Статті в журналах з теми "Blade root Joint"

A review of the root causes and mechanisms of damage and failure to wind turbine blades is presented in this paper. In particular, the mechanisms of leading edge erosion, adhesive joint degradation, trailing edge failure, buckling and blade collapse phenomena are considered. Methods of investigation of different damage mechanisms are reviewed, including full scale testing, post-mortem analysis, incident reports, computational simulations and sub-component testing. The most endangered regions of blades include the protruding parts (tip, leading edges), tapered and transitional areas and bond lines/adhesives. Computational models of different blade damage mechanisms are discussed. The role of manufacturing defects (voids, debonding, waviness, other deviations) for the failure mechanisms of wind turbine blades is highlighted. It is concluded that the strength and durability of wind turbine blades is controlled to a large degree by the strength of adhesive joints, interfaces and thin layers (interlaminar layers, adhesives) in the blade. Possible solutions to mitigate various blade damage mechanisms are discussed.

Stresses due to resonant vibrations induce fatigue damage in turbomachinery blades jeopardizing their structural integrity. Damping plays a fundamental role in passive control of resonant stresses. In the present work the effect of ‘crowning’ of dovetail joints on blade-root friction damping is for the first time investigated. In detail, the damping of a simplified blade is measured under varying centrifugal load for two different joint geometries: a customary dovetail attachment and a ‘crowned’ one. A theoretical model is developed to quantify the damping generated at the contact surfaces. Experimental results and analytical predictions are compared.

The importance of a reliable blade root connection has grown due to the higher-gravity-induced edgewise loads on the blade root that resulted from the recent increased size and weight of a wind turbine rotor blade. To avoid the loosening of a bolt joint connection or even consecutive blade failures, the stress concentration factor (SCF) at the bolt thread root that is sensitive to fatigue should be understood comprehensively. In this work, two-dimensional and three-dimensional finite element (FE) analysis methods were used to determine the SCF at the bolt threads both between an insert and a M42 bolt used for a large offshore blade, and between a M42 bolt and a nut. The effect of various geometric parameters on the SCF were also investigated, which included shank diameter, nut height, nut type, and relief cone. Results showed that the decreased diameter of a M42 bolt shank diameter was the dominant design driver in reducing the stress concentration factor by 40%, from 3.94 to 2.32. The round nut type was also a recommended factor to be implemented to connect bolts and inner pitch bearing with an additional 10% SCF reduction. The relief cones applied to bolt threads and insert threads also contributed to the reduction of SCF to 2.01, a 49% reduction in total. This work not only provides guidelines by which to choose the proper geometry of the bolt and nut for a large blade, but also could be beneficial in designing bolted joint connections of segment or modular blades.

Abstract The article addresses the improvement of compressor impeller configuration methods. One of the key parameters of compressor blade assembly quality is the uniform tension in the blade shroud joint. The authors have developed an algorithm for arranging the blades in the compressor impeller, which allows reducing the tension and ensures its uniform distribution. The algorithm kernel is based on a mathematical model developed for calculating shroud tension areas on the suction side and pressure side based on controlled deviations of the airfoil and shroud. The computed areas are used to sort the blades by the increasing tension area on the suction side and the decreasing one on the pressure side. At the final stage, the blades are arranged by their successive choice from among two rows and each next blade from the rows is installed in the casing, next to the pre-installed blades, with the change in the bypass direction. The algorithm is written in Python; 1,000 computing experiments were made to simulate the deviation of the parameters for 84 blades in the set. The algorithm function was compared to the arbitrary arrangement of the blades. As a result, the root-mean-square deviation of the originating tensions decreased from 0.54 mm2 to 132 mm2.

The article addresses the improvement of compressor impeller configuration methods. One of the key parameters of compressor blade assembly quality is the uniform tension in the blade shroud joint. The authors have developed an algorithm for arranging the blades in the compressor impeller, which allows reducing the tension and ensures its uniform distribution. The algorithm kernel is based on a mathematical model developed for calculating shroud tension areas on the suction side and pressure side based on controlled deviations of the airfoil and shroud. The computed areas are used to sort the blades by the increasing tension area on the suction side and the decreasing one on the pressure side. At the final stage, the blades are ar-ranged by their successive choice from among two rows and each next blade from the rows is installed in the casing, next to the pre-installed blades, with the change in the bypass direction. The algorithm is written in Python; 1,000 computing experiments were made to simulate the deviation of the parameters for 84 blades in the set. The algorithm function was compared to the arbitrary arrangement of the blades. As a result, the root-mean-square deviation of the originating tensions decreased from 0.54 mm2 to 0.132 mm2.

The unsteady numerical simulation of fluid field and structural transient dynamic analysis of axial flow pump were carried out at three operating conditions based on fluid-structure interaction method. Numerical results show that the maximum equivalent stress of impeller occurs at the joint region of the impeller blade root and the hub, and the maximum deformation of impeller occurs at the tips of blade leading edges. The frequency-domain of the maximum equivalent stress and outlet pressure fluctuation of impeller are mainly affected by the impeller blade passing frequency.

The vibration dissipation mechanism of the rotating blade with a dovetail joint is studied in this paper. Dry friction damping plays an indispensable role in the direction of vibration reduction. The vibration level is reduced by consuming the total energy of the turbine blade with the dry friction device on the blade-root in the paper. The mechanism of the vibration reduction is revealed by the variation of the friction force and the energy dissipation ratio of dry friction. In this paper, the flexible blade with a dovetail interface feature is discretized by using the spatial beam element based on the finite element theory. Then the classical Coulomb-spring friction model is introduced to obtain the dry friction model on the contact interfaces of the tenon-mortise structure. What is more, the effects of the system parameters (such as the rotating speed, the friction coefficient, the installation angle of the tenon) and the excitation level on blade damping characteristics are discussed, respectively. The results show that the variation of the system parameters leads to a significant change of damping characteristics of the blade. The variation of the tangential stiffness and the position of the external excitation will affect the nonlinear characteristics and vibration damping characteristics.

The operational environment of offshore wind turbines is much more complex than that of onshore wind turbines. Facing the persistent wind and wave forces, offshore wind turbines are prone to vibration problems, which are not conducive to their long-term operation. Under this background, first, how the wave affects the vibration characteristics of offshore wind turbines is analyzed. Based on the existing wave and wave load models, we analytically show that there exist fluctuating components related to the hydrodynamic frequency in the aerodynamic load and aerodynamic torque of offshore wind turbines. Simulation results based on a GH Bladed platform further validates the analysis. Second, in order to reduce the joint impacts of the wave, wind shear and tower shadow on the wind turbine, a variable pitch control method is proposed. The integrated tower top vibration acceleration signal is superimposed on the collective pitch reference signal, then the triple frequency (3P) fluctuating component of the wind turbine output power and the azimuth angle of each blade are converted into the pitch angle adjustment signal of each blade, which is superimposed on the collective pitch signal for individual pitch control. The simulation results show that the proposed pitch control strategy can effectively smooth the fluctuation of blade root flap-wise load caused by wind and wave, and significantly reduce the fluctuation of aerodynamic torque and output power of offshore wind turbines.

The butt part of the main rotor blade (RB) of the helicopter is presented. A geometric model of the calculated connection was developed using the CATIA V5 system. With the help of the ANSYS system, a finite element model of the butt part of the main rotor blade was developed, and the calculation and analysis of the characteristics of the results obtained were carried out. To describe the response of materials to an external action, a model of an elastically deformable isotropic body was used with the assignment of the corresponding elastic constants of the material. The case of loading a bolted joint by a centrifugal force arising during the rotation of a blade is considered. To model the contact interaction, a generalized surface-to-surface contact interaction model was adopted. The analysis of the calculation results includes the determination of reactions at the attachment points, the values of the maximum displacements of structural elements and stresses in the stress concentration zones. In the course of the calculation, reactions were determined at the points of attachment of the tip along the holes in the lugs. The nature of the deformation of the bolted joint as a whole and of its individual elements is analyzed. The assessment of total displacements and displacement components is carried out. To assess the static and fatigue strength of the elements of the bolted connection of the tip with the blade spar, the stresses in the load-bearing elements were analyzed for typical concentrators. When assessing the static strength, the distribution of equivalent stresses according to Mises was analyzed. The distribution of stresses in the zone of holes along the rows is analyzed, starting from the root section in the direction of increasing the Y coordinate. The maximum von Mises stresses for typical stress concentration zones were compared with the ultimate strength of the structural element material. To assess the fatigue strength, we analyzed the distribution of the main tensile stresses in the load-bearing elements by typical stress concentrators. The maximum values of these stresses were compared with the fatigue limit of the structural element material.

Using active control methods for load mitigation in wind turbines could greatly reduce the cost of per kilowatt hour of wind power. In this work, the combined pitch and trailing edge flap control (CPFC) for load mitigation of wind turbines is investigated. The CPFC includes an individual pitch control (IPC) loop and a trailing edge flap control (TEFC) loop, which are combined by a load frequency division control algorithm. The IPC loop is mainly used to mitigate the low frequency loads, and the TEFC loop is mainly used to mitigate the high frequency loads. The CPFC adopts both an azimuth angle feed-forward and a loads feedback control strategy. The azimuth angle feed-forward control strategy should mitigate the asymmetrical loads caused by observable disturbances. and the loads feedback control strategy should decrease asymmetrical loads by closed loop control. A simulation is carried out on the joint platform of FAST and MATLAB. The simulation results show that the damage equivalent load (DEL) of blade root out-of-plane bending moment is reduced by 53.7% while using CPFC, compared to collective pitch control (CPC); and the standard deviation of blade tip out-of-plane deflection is reduced by 50.2% while using CPFC, compared to CPC. The results demonstrate that the CPFC can mitigate the fatigue loads of wind turbines as anticipated.

Abstract. Observations of large coherent fluctuations are used to define a probabilistic model of coherent gusts with direction change. The gust model provides the joint description of the gust rise time, amplitude, and directional changes with a 50-year return period. The observed events are from a decade of measurements from a coastal site in western Denmark, making the derived gust model site specific. In conjunction with the gust model, a yaw controller is presented in this study to investigate the load implications of the joint gust variables. These loads are compared with the design load case of the extreme coherent gust with direction change (ECD) from the IEC 61400-1 Ed.4 wind turbine safety standard. Within the framework of our site-specific gust model we find the return period of the ECD to be approximately 460 years. From the simulations we find that for gusts with a relatively long rise time the blade root flapwise bending moment, for example, can be reduced by including the considered yaw controller. From the extreme load comparison of the ECD and the modeled gusts we see that by including the variability in the gust parameters the load values from the modeled gusts are between 20 % and 74 % higher than the IEC gusts.

For large off-shore wind turbines, blades with relative low blade mass are becoming more important. The economic use of large-tow carbon fibers can help achieve lower blade masses. Basic material design data have been established for two promising material combinations, including the fatigue properties for Panex33/epoxy. Blade root joints have been developed in a carbon/glass combination, resulting in a better price performance ratio. The initial cost assessment on a blade dominated by severe fatigue loads shows that application of carbon fibers in the spar leads to cost reductions.

An approach is developed to analyze the multiharmonic forced response of large-scale finite element models of bladed disks taking account of the nonlinear forces acting at the contact interfaces of blade roots. Area contact interaction is modeled by area friction contact elements which allow for friction stresses under variable normal load, unilateral contacts, clearances, and interferences. Examples of application of the new approach to the analysis of root damping and forced response levels are given and numerical investigations of effects of contact conditions at root joints and excitation levels are explored for practical bladed disks.

Periwinkle, a perennial commonly used as a summer bedding plant, is known as the source of vinca alkaloids used to treat lymphocytic leukemia and Hodgkin's disease. It is also one of the natural hosts of many phytoplasma diseases, such as X-disease of major Prunus species, aster yellows, and ash yellows diseases. Therefore, periwinkle is an ideal plant species for phytoplasma disease research, such as disease transmission, species resistance, and resistant gene screening. Periwinkle tissue culture was established by incubating sterile seeds in hormone-free Murashige and Skoog (MS) medium. Plants were successfully regenerated from in vitro leaf tissues of periwinkle. Adventitious shoots were induced when leaf tissues were cultured on Murashige and Skoog (MS) medium or woody plant medium (WPM) supplemented with benzyladenine (BA) and naphthaleneacetic acid (NAA). Nearly 75% of leaf explants produced shoots in both media with 10–20 μm BA and 1 μm NAA. A mean of 4.3 shoots was produced from each explant cultured on WPM, whereas only 2 shoots were produced on MS medium under 16-h photoperiod. Leaf explants under dark treatment for 2 weeks produced big callus only, indicating that light is necessary for shoot formation. Most adventitious shoots were induced from the joint of leaf blade and petiole. In vitro shoots (>1.5 cm) were easily rooted in half-strength MS medium. Addition of NAA dramatically increased root number, with more than 20 roots being induced in 5 μm NAA medium. Rooted plants were transferred to potting medium and grown in a greenhouse.

In machinery structures with joints, the contact pressures at contact interfaces are usually high enough to ensure that the contacting components stay joined and the gross slip does not occur. Nevertheless, the small relative slip over parts of the contact interface, i.e. the microslip, contributes significantly to the vibration damping. In the high-fidelity analysis of practical bladed discs, the macroslip model cannot provide sufficient accuracy for the predictive analysis of the properties of the friction damping in the contact interfaces. In this article, numerical studies of microslip damping effects is performed using 2D and 3D models of blade root joints. Analysis of hysteresis loops is performed to assess the influence of modeling parameters: choice of reference points, mesh configurations, and other physical parameters. The impact of the physical parameters, such as the contact geometry, friction coefficient, contact stiffness and tangential and normal loading, on the friction damping is numerically examined. The numerical results demonstrate the possibilities of microslip prediction using finite element modeling and show the microslip friction damping effects using simplified and realistic blade root models.

The analysis of both foreign and domestic experience in the use of polymer composite materials in the structures of the lifting surfaces of a helicopter (blades, wing, stabilizer, fin), as well as the technological features of the manufacture of such structures is performed. The design and technological and operational advantages and disadvantages of composite blades compared to all-metal blades are noted. The load-carrying structures of the composite main rotor blades of a helicopter, as well as the schemes of special joints of the MR blade and the polymer composite materials package are considered. The route scheme for manufacturing of the composite blade of a helicopter is presented. The technological features of manufacturing the composite spar of a blade are analyzed by the methods of lay-up and winding-on. The scheme and route technology for manufacturing the tail section of a blade, including the scheme of lay-up and molding of composite covers and ribs, are presented. The efficiency of the equipment for automatic cutting of the roll prepreg and manual lay-up of the prepreg layers with the help of a laser projector is noted. The technological tasks of special software for lay-up CNC equipment are given. The technological transitions of the general assembly-bonding of a helicopter composite blade in the assembly jig are presented. Recommendations are given on the method of manufacturing a monoblock lifting surfaces of type of a wing, tail pylon and helicopter stabilizer from polymer composite materials using automated winding-on. A scheme of surface reinforcement is proposed. It allows to obtain a variable wall thickness from the root rib to the end rib. The trajectories of movement of the working bodies of a three-coordinate CNC winding machine for their implementation are determined. A variant of a computer simulation of the stages of lay-up of a reinforcing tape on a technological mandrel is shown. The technology of manufacturing a low aspect wing made of polymer composite materials by the method of automated winding is presented.

It is important and difficult for the complicated surface processing in mechanical industry. In this paper, an improved algorithm for trajectory planning is proposed in impeller surface processing by using 6-DOF cutting-robot. Taking a single finished path of the impeller blade as an example, the feedrate of the cutter, bow height error, cutter-orientation and position are planned by the B-spline interpolation algorithm, the best cutting trajectory is obtained. On the basis of trajectory planning, the optimal movement scheme of 6-DOF cutting-robot joints is obtained, the 6-DOF cutting-robot feedrate and trajectory smooth transition is achieved and the joints movement adaptive adjustment is completed. Finally, the angles, the angular velocitys of the joints and their interrelated properties are analyzed. The research works indicate that the robot joint angle curves are continuous and stable, which has met the requirements of smooth movement of the robot, and the results show that the trajectory planning is effective and practical.

This paper focuses on the contact characteristics of the blade root joints subjected to the dry friction damping under periodic excitation. The numerical method and experimental procedure are combined to trace the contact behavior in the nonlinear vibration conditions. In experimental procedure, a novel excitation method alongside the accurate measurements is used to determine the frequencies of the blade under different axial loads. In numerical simulations, local behavior of contact areas is investigated using the reduction method as a reliable and fast solver. Subsequently, by using both experimental measurements and numerical outcomes in a developed code, the global stiffness matrix is calculated. This leads to find the normal and tangential stiffness in the contact areas of a dovetail blade root joints. The results indicate that the proposed method can provide an accurate quantitative assessment for investigation the dynamic response of the joints with focusing the contact areas.

Abstract The length of rotor blades is showing continuous growth for future wind energy turbines leading to high bending moments, which must be transferred to the hub by the root section. As the growth of the root diameter is limited by factors such as transportability, motivation to improve the load carrying capacity without changing the geometry is high. Hybridisation with metals shows a possibility to intrinsically increase the bearing strength of fibre-reinforced plastics. This publication presents experimental investigations into hybrid laminates to be used in so-called T-joints for connecting rotor blades to the hub of the nacelle of a wind energy turbine. An overview is given about the bearing strength of several material combinations hybridising glass- and carbon fibre-reinforced plastics (GFRP, CFRP) with aluminium, titanium and steel alloys. A GFRP-steel-hybrid can be identified as a material with a high reinforcing effect even for low amounts of steel. A hybrid T-joint demonstrator is manufactured by resin infusion and tested under static tension. In comparison with a GFRP reference, a joining strength increase of about 33% is achieved for a steel content of 3%. Further coupon level tests reveal a weak spot in the transition zone between the monolithic GFRP region and full hybrid region as the static and fatigue resistance clearly decreases in comparison with monolithic GFRP and full hybrid references.

Objetivou-se neste trabalho gerar e validar 16 modelos simplificados para estimar a área do limbo foliar de árvores de Tectona grandis L. Foram coletadas folhas de árvores adultas em plantios homogêneos e em matrizes isoladas, nos estratos superior, médio e basal das copas, totalizando 1800 folhas. A área foliar real foi determinada usando o integrador de área foliar “Area Meter” (LI-3100C). Nos modelos de estimativa, considerou-se a área foliar como variável dependente, massa seca (MS) e as dimensões lineares da folha (comprimento – C e largura do meio da folha - L) como variáveis independentes. Para calibração e validação estatística, utilizou-se 70% e 30% das folhas, nesta ordem. Na avaliação do desempenho estatístico (validação) empregou-se o erro médio (MBE), raiz quadrática do erro médio (RMSE) e índice de ajustamento de Wilmott (dw). Empregou-se o método dos valores ponderados dos indicativos estatísticos (Vp) para definir qual a melhor modelo. Os modelos que empregam medidas conjuntas de C e L proporcionam melhores estimativas da área do limbo foliar de T. grandis, sendo indicado o modelo AF = 0,5776 C*L, que apresenta superestimava de 13,98 cm², espalhamento de 61,99 cm² e ajustamento de 0,99. Considerando a massa seca, recomenda-se o modelo AF = 91,9164 MS.Palavras-chave: Tectona grandis L.; indicativos estatísticos; morfometria foliar. ALLOMETRIC EQUATIONS FOR LEAF BLADE AREA ESTIMATION OF TEAK ABSTRACT: The objective of this work was to generate and validate 16 simplified models to estimate the leaf limb area of Tectona grandis L. trees. Leaves of adult trees were collected at homogeneous plantations and isolated matrices, in the upper, middle and basal strata of the crowns totalizing 1800 sheets. The actual leaf area was determined using the “Area Meter” leaf area integrator (LI-3100C). In the estimation models, the leaf area was considered as a dependent variable, dry mass and leaf linear dimensions (length - C and width of the middle leaf - L) as independent variables. For calibration and statistical validation, 70% and 30% of the leaves were used in this order. In the statistical performance evaluation (validation) we used the mean error (MBE), quadratic root mean error (RMSE) and Wilmott adjustment index (dw). We used the method of weighted values of statistical codes (Vp) to define the best model. Models employing C and L joint measurements provide better estimates of T. grandis leaf limb area, with the AF = 0.5776 C * L model being overestimated 13.98 cm², scattering 61.99. cm² and adjustment of 0.99. Considering the dry mass, the model AF = 91.9164 MS is recommended.Keywords: Tectona grandis L.; statistics indicatives; leaf morphometry.

In quadruped robot, there is the strong correlation of kinematic parameters for the joints of two-section leg, and it is difficult to realize the decoupling of rhythm and pattern over rough terrains. In this paper, we investigated the physiological feature, locomotion characteristics and main function of shoulder blade of quadrupeds, and based on the results, we proposed a stratified control system on the three-section leg to realize better adaptation of a robot to terrains. Through the active control of shoulder blade (frequency and amplitude) and the coupled passive control of upper arm and forearm, a leg may adjust to the terrains of different elevations without changing the movement state of shoulder blade and body speed. In addition, the foot trajectory was planned and a rough terrain was created for testing the athletic ability of a three-section leg, and the validity of the proposed control system is confirmed through simulation.

Abstract This paper presents a methodology of mapping the bead geometry, deposited on a fillet like joint, as a function of the input parameters of the synergic pulsed gas metal arc welding process and the welding position, to allow the planning of repairing hydroelectric turbine runner blades by means of robotic welding. The challenges of automating the repair process; further, to choosing the best welding parameters, include the definition of the path that the robot must follow during the metal deposition, such that it is able to fill completely the damaged blade cavity, by means of producing overlapped layers from several individual weld beads. Thus, this research focused on developing statistical prediction models that could map the geometric variations of the weld bead section as function of the input parameters (wire feed speed, welding speed and bead face rotation angle). For this purpose, the bead section was approximated by a parallelogram whose height, width and inclination angle were considered as dependent variables. Several welding trials were carried out according to a central composite experimental design and three multiple regression models were obtained. Here, the physics is used to interpret the influence of the input parameters on the output results.

Joining of different nickel-base superalloys could simplify the manufacturing of turbine blades. The used technique of choice is transient liquid phase bonding, which is an established repair technology for high temperature components. Two nickel-base superalloys with distinct composition and grain structure are bonded and the joints are analysed regarding the microstructure. To quantify the mechanical properties of these joints, tensile and short term creep rupture tests were performed at room and elevated temperatures.

Purpose This paper aims to provide a posture generation method of robot deposition paths based on intersection topology, which is helpful to contribute to improving the flexibility and deposition capability of the deposition system. Design/methodology/approach Via the geometry information and normal vector information of the stereolithography (STL) model, the intersecting edge information is generated and the topological relationship of the model is established. Through the removal of redundant points for the STL model and the sort of robot path points, the position information of robot path points is obtained. According to the geometric relationship between the normal vector information of the STL model and the robot deposition path points, combining with the robot posture representation method of roll-pitch-yaw angles, the posture information of path points is achieved. Then, the generation from CAD model of parts to robot paths for laser melting is realized, and the experimental verification is carried out. Findings For simple parts, the laser melting process can be completed without the posture information of deposition paths. However, in the melting process of a turbine blade, there are some accumulated burls on the sidewall. The posture generation method of robot deposition paths based on the intersection topology can solve this problem. The light spot of deposition points irradiates on the surface of the forming part, and the forming process can proceed smoothly. Practical implications As a motion platform in laser melting deposition (LMD), the application of the multi-joint robot can improve the flexibility and deposition capability of the deposition system, as well as promote the LMD application for individuation manufacturing, parts repair and green remanufacturing. Originality/value The posture is essential for robot deposition paths. This paper first proposes a posture generation method of deposition paths for LMD to improve the flexibility and deposition capability of LMD systems.

Category: Ankle Arthritis; Arthroscopy; Trauma Introduction/Purpose: One of the options for the surgical treatment of tibial pilon fracture is the circular external fixator. Similar results are found in the literature, with good outcomes in relation to a low incidence of infection, osteomyelitis and soft tissue injuries compared to open reduction and internal fixation. Even so, evolution to a probable arthrodesis occurs in 3-27% of cases, showing that the prognosis for this type of fracture is dismal. Options for performing joint fusion include open arthrotomy with joint decortication and internal fixation (plates and/or screws), in addition to arthroscopic joint preparation, a method that has been gaining popularity since 1983, in its first description. Fusion through circular external fixation is an excellent option that has shown good results in the literature. Methods: Patient with left tibial pilon fracture. Uniplanar external fixation was performed in the emergency room, with subsequent conversion to transarticular circular external fixation. After 4 months of review, the patient has evidence of tibiotarsal arthrosis. It was decided to perform arthrodesis using the arthroscopic technique, performing joint compression with circular external fixation, already installed in the patient. Spinal anesthesia was performed on the patient and the Smarch tourniquet was used. First, access to the anteromedial portal, trocar and optic passage was obtained, and the intermediate dorsal cutaneous branch of the superficial peroneal nerve was identified laterally, and the anterolateral portal was constructed. Through these portals, a 4.5mm Shaver blade was used to perform curettage and joint debridement, in addition to curettes and osteotomes. In addition to arthroscopic control, fluoroscopic observation was also performed for adequate joint preparation.Finally, joint compression was performed with the device already installed. Results: The patient presented complete consolidation of the tibio-tarsal arthrodesis. At the moment (2 years and 10 months postoperatively) the patient does not use crutches/gait accessories, does not limit his daily activities due to foot problems, does not have difficulty going down and up stairs, has good ankle alignment, plantigrade foot, has no joint pain and can walk long distances. Conclusion: This work showed a technique rarely reported or cited in the orthopedic literature, not presenting any article as an original description. Supported by the description of the procedure by the robust final functional results of the patient in question, this report establishes the basis for the widespread method and new works to emerge to enrich the debate and study around arthroscopic ankle arthrodesis using the Ilizarov method.

Modern lightweight structures containing hybrid materials allow an improvement of the weight-specific properties. However, to exploit the potential as far as possible novel joint concepts are necessary, enabling an economic structure manufacturing. The DFG-researcher group Schwarz-Silber (FOR 1224) at the University of Bremen aims to explore and develop interface structures for advanced FRP-Al compounds. Considering textile, welding and casting techniques novel joint concepts are under development, in five interdisciplinary projects. Within their work the researcher group focuses on three concepts realizing the transition structures: the usage of wires (titanium), foils (titanium) and fibres (glass fibre) as transition elements between CFRP and aluminium. Typical examples for such hybrid structures can be found in products from the aerospace industry (e.g. hull segments), the car industry (e.g. CFRP roof structures), but also in general mechanical engineering (e.g. rotor blade elements). In this paper, the joint configuration based on titanium wires and a laser beam conduction welding process will be presented. As beam source a lamp pumped Nd:YAG laser (HL4006D) was used. First specimens obtained will be discussed with respect to their properties. It will be shown that the novel approach is in principle suitable to produce load-bearing CFRP-aluminium structures. The wire concept represents a parallel arrangement of miniaturized loop connections. It is characterized by joining a CF-Ti-textile to an aluminium sheet. A carbon fibre loop is threaded through a titanium wire loop by textile technologies on one side. On the side opposite to the CF, the titanium wire loops of the CF-Ti-textile are joined to an aluminium component by welding or casting. A double-sided laser beam heat conduction welding process was applied, for both concepts. During processing, the laser beam was travels along the aluminium edge. The titanium-aluminium structure is welded in two steps. During the first step (i.e. the first weld pass) the aluminium and titanium are heated by the defocused laser beam simultaneously on both sides. An aluminium melt pool is formed, supported by the action of gravity and a certain amount of pre-heating of the titanium-wire or the titanium-foils by the laser beam and by heat conduction through the aluminium melt pool. In the second, immediately subsequent step (i.e. the second weld pass), due to a pre-heating of the materials by the first pass and an increased heat transfer between both materials, a complete wetting of the titanium structures in the joining zone is achieved.

A hybrid energy harvester is presented in this paper to harvest energy from water flow motion and temperature difference in an irrigating pipe at the same time. The harvester is based on the integration of thermoelectric and electromagnetic mechanisms. To harvest the water flow motion, a turbine fan with magnets that are attached on the blades is placed inside of the water pipe. Multiple coils turn the water flow energy into electricity with the rotation of the turbine. The thermoelectric generators (TEGs) are attached around the pipe, so as to harvest energy due to temperature difference. For a maximum temperature difference of 55 °C (hot side 80 °C and room temperature 25 °C), twelve serial-connected TEGs can generate voltage up to 0.346 V. Under a load resistance of 20 Ώ, the power output of 1.264 mW can be achieved. For a maximum water flow rate of 49.9 L/min, the electromagnetic generator (EMG) can produce an open circuit voltage of 0.911 V. The EMG can be potentially used as a water flow meter due to the linear relationship between water flow rate and output voltage. Under the joint action of TEG and EMG, the maximum terminal voltage for TEG is 66 mV and for EMG is 241 mV at load resistances of 10 and 100 Ώ, respectively, resulting in a corresponding power output of 0.435 and 0.584 mW.

Objectives During arthroscopic or open joint surgery, articular cartilage may be subjected to mechanical insults by accident or design. These may lead to chondrocyte death, cartilage breakdown and posttraumatic osteoarthritis. We have shown that increasing osmolarity of routinely used normal saline protected chondrocytes against injuries that may occur during orthopedic surgery. Often several liters of irrigation fluid are used during an orthopedic procedure, which is usually kept at room temperature, but is sometimes chilled. Here, we compared the effect of normal and hyperosmolar saline solution at different temperatures on chondrocyte viability following cartilage injury using in vitro and in vivo models of scalpel-induced injury. Design Cartilage injury was induced in bovine osteochondral explants and the patellar groove of rats in vivo by a single pass of a scalpel blade in the presence of normal saline (300 mOsm) or hyperosmolar saline solution (600 mOsm, sucrose addition) at 4°C, 21°C, or 37°C. Chondrocytes were fluorescently labeled and visualized by confocal microscopy to assess cell death. Results Hyperosmolar saline reduced scalpel-induced chondrocyte death in both bovine and rat cartilage by ~50% at all temperatures studied (4°C, 21°C, 37°C; P < 0.05). Raising temperature of both irrigation solutions to 37°C reduced scalpel-induced cell death ( P < 0.05). Conclusions Increasing the osmolarity of normal saline and raising the temperature of the irrigation solutions to 37°C reduced chondrocyte death associated with scalpel-induced injury in both in vitro and in vivo cartilage injury models. A hyperosmolar saline irrigation solution at 37°C may protect cartilage by decreasing the risk of chondrocyte death during mechanical injury.

Abstract INTRODUCTION Hemophilia A (HA) is a rare inherited genetic disorder linked to the X chromosome, characterized by joint bleeding in patients with severe disease with <1% of factor VIII (FVIII)(White et al. Thromb Haemost 2001). However, there are cases of severe HA with less bleeding than usual and it has been postulated that there must be other contributors to the hemorrhagic phenotype, including a platelet dysfunction (Van Bladel et al. Haematologica 2011). In this study we analyzed platelet reactivity in a cohort of 16 male patients with severe HA in prophylactic treatment by flow cytometry. The control group was 15 healthy male subjects. METHODS A longitudinal prospective observational study cohort was conducted. The study was performed according to the Declaration of Helsinki of 1975 (revised 1983), and was approved by the Ethics Committee of our Institution. Sixteen HA male patients without FVIII inhibitor aged 9-39 years (mean 22,75 years, SD 11,428) and 15 adult male healthy volunteers aged 26-48 years (mean 36,4 years, SD 6,6) were included. All subjects had normal platelet counts (150-450x103/µl). The blood was collected by antecubital venipuncture and avoiding the use of tourniquet to minimize the spontaneous activation of platelets during extraction. For HA patients blood samples were taken immediately before FVIII infusion (basal sample, 72h without FVIII) and 15 minutes after the infusion of FVIII. Levels of factor FVIII in plasma were determined using a chromogenic method. We analyzed platelet responsiveness, using the thrombin receptor activator peptide-6 (TRAP-6) as agonist, measuring the expression of CD62P and CD63 by flow cytometry. For microparticles analysis, percentages and number of events positive for CD62P and CD41 were gated for Annexin-V+ subpopulation. Endothelial cell-derived microparticles were identified as CD144+CD41-. To calculate the absolute count we considered the final volumes of each tube and it was expressed in events/µL for each subpopulation (Annexin-V +, CD41+, CD144+ and CD62P+). For the analysis of cytoplasmic free calcium release, whole blood was labelled with PerCP-Cy5.5-human anti-CD61 and the calcium sensitive dye Fluo-4-AM for 15 min at room temperature. Following adjustment of the basal fluorescence, samples were stimulated with the agonists TRAP-6 or adenine-5«-diphosphate sodium salt (ADP) and analyzed for 5 min by flow cytometer. Ionophore A23187 was used as a positive control for calcium mobilization. Afterwards mean fluorescence intensity values were analysed with the Kaluza flow cytometry analysis software (Beckman Coulter). RESULTS Statistical analysis was carried out using SPSS statistical software version 19.0.All values were expressed as mean ± SD for each experimental group.To compare the results in HA patients before and after administration of FVIII we used the t-Student test for means related, to compare HA patients and the control group we used the t-student test for independent samples. Data of calcium were analyzed by one-way analysis of variance followed by Tukey-Kramer for multiple comparisons. The minimum acceptable level of significance wasp<0.05. Basal levels of FVIII in plasma were4,58 ± 6,4%. The mean fluorescence intensity for CD62P after stimulation with TRAP was significantly lower in HA patients after infusion of FVIII compared to basal levels (p<0,05)(Table 1). Regarding microparticles (MPs), we detected higher expression of CD41+ MPs in HA patients after infusion of FVIII compared to basal expression, but not for CD41+CD62P+ MPs. Also, percentage of CD144+ MPs were significantly lower in HA patients after FVIII infusion (Table 2). Moreover, we did not find statistically significant differences comparing the release of calcium between the different groups (Table 3). CONCLUSION In this study severe HA patients in prophylactic treatment displayed normal platelet activation and microparticles plasmatic levels. However, the platelet activation marker CD62P after TRAP agonist and the endothelial cell origin microparticles expression were lower 15 minutes after the infusion factor VIII. Acknowledgments We wish to thank to Pfizer providing economic support to this project. Disclosures Melero-Amor: Pfizer: Research Funding. García Candel:Pfizer: Research Funding. García:Pfizer: Research Funding. Romecin:Pfizer: Research Funding. Iyu:Pfizer: Research Funding. Cabañas-Perianes:Pfizer: Research Funding. Pérez:Pfizer: Research Funding. O´Connor:Pfizer: Research Funding. Moraleda:Pfizer: Research Funding. Marín:Pfizer: Research Funding. Blanquer Blanquer:Pfizer: Research Funding.

Supplemental Instruction (SI) has been a successful implementation into institutions worldwide. It serves as a means of reducing attrition and increasing the overall learning of course material. The City College of New York (CCNY) has recently implemented SI to General Chemistry I courses to examine whether or not SI would help students succeed in the course and understand and grasp the course material better. SI was made available several times a week during flexible times to students who are struggling in the course. Our method of data collection is a Likert-type and open-ended questionnaire that was distributed at the end of each of the semesters to SI participants in an anonymous fashion. Furthermore, we compared the grades and performance of students participating in SI with those who did not. The collected data enabled us to examine the impact of implementing Supplemental Instruction (SI) in General Chemistry I at CCNY. Our data show that SI was beneficial, contributed to improving students’ understanding of course material, and increased their success rate. About 80 percent of students who failed the first exam and participated in SI obtained a passing grade compared to 11 percent of those who did not.Keywords: supplemental instruction, chemistry education research, student learningINTRODUCTION Supplemental instruction is derived from the term developmental education and stems from a branch of Learning Assistance Centers or LACS [1]. To better understand the origins of Supplemental Instruction, we must first understand the framework that set up this type of education. Developmental education originates in the 1600s and focuses mainly on the assumption that each student has multifaceted talents that can be developed academically, opposed to focusing on the deficits of a student [1]. The main goal was to naturally adapt the students’ population to higher education through means of social and academic domains allowing the students to grow in multiple dimensions in their academic skills [1].Developmental education later paved the way for academic programs such as Learning Assistance Centers (LACs). It was viewed as an extension of the classroom and did not discriminate between faculty and students, and within the student population did not discriminate between students who performed to standard and those who performed below par. LACs were for everyone who wanted to be academically enriched [1]. As a new program, LACs had six main objectives: “higher course grades for participating students; central location for students to receive tutorial assistance; a referral source to other helping agencies; a comprehensive library of basic study aids; a training agency for paraprofessionals, peer counselors, and tutors; and a center for faculty development.” [1]. These goals made it very clear that this service was not to be mislabeled as remedial, which was a main topic of interest when it comes to implementing new services, like this one, in schools. LACs are essentially a tool used to attain higher education, not provide a remedial course. Another important reason as to why LACs were adopted into other higher education institutions is to increase student retention [1]. LACs jump-started improved learning across campuses not only in the United States but across the world.In the 1990’s developmental or remedial courses were not allowed to be offered at public four-year universities, thus making supplemental instruction a very attractive candidate to solving the issue with students’ academic integrity and attrition [1]. College faculty members were drawn to SI due to its minute fiscal commitment and that it strongly promoted individual self-learning for the students, this meant less time spent teaching for instructors [1].SI or supplemental instruction is as it states - supplemental instruction offered to the students enrolled in a course. SI gives the students the opportunity to work in a cooperative setting on problems and is supported by peer instructors [2]. SI works to increase academic performance and retention but utilizing both collaborative studying in addition to independent studying and analysis of study strategies. SI sessions are offered for traditionally difficult high risk course; ‘historically difficult’ courses are also identified by analyzing the grade distribution of courses throughout each academic division, “courses in which 30% or more of the students receive D or F grades or withdraw, become targets” [3]. One of the main factors that attribute to the individuality of SI programs is that it focuses on historically difficult courses [4] and large classes where students have little opportunity for interaction with the professor or other students [5]. Labeling a course as historically difficult allows you to categorize the class as challenging without placing blame on the professor or the students.SI sessions are scheduled on a weekly basis and all students enrolled in the course are encouraged to join. SI sessions act as a continuation of the lesson learned during in-class lecture with the instructor. Being that SI sessions are not tied down to class time, students can attend whenever and however many times they wish without the restriction of a required course preventing them. Constant feedback will be given based on the student’s grasp of the material taught in class, thus giving them ample time and motivation to alter their study methods to adapt, if need be. Research on SI suggests that problem-solving skills and study strategies learned in SI courses are transferable to other courses which leads to improved performance [6]. Supplemental instruction sessions are typically led by an SI leader, who would be a former student that succeeded in the same course, however it is not uncommon for a professor to join an SI session for a course. SI may improve students’ retention and graduation because it offers the students the opportunity to network socially which speeds up the acclimatization to the college experience [7].SI provides a way to combine “how do I teach myself this” with “what do I need to know”. While SI helps students gain a more thorough understanding of the material, it also helps students to condition themselves and alters their thinking to accommodate for the type of information they are processing. SI differs from a remedial tutoring course because it is created based on the course versus the students [1]. This potentially makes attending SI sessions more attractive to students who are afraid or shy to ask for help.SI is not a remedial course, it is considered a mediator connecting the gap between the new information presented to students and the students current knowledge and practices, “SI bridges the gap between the current knowledge base and the acquisition of new knowledge by focusing on the refinement of the learning skills indispensable for acquiring new knowledge” [8]. Successfully implemented SI programs were able to track those students who attended and the impact it made towards their grade, for data that was collected institutionally [9]. SI can be effectively used to develop study skills, increase motivation and improve performance in participants [10].According to Wolfe, “…there appear to be benefits of SI in courses where students are being newly introduced to chemical concepts and methods, but these benefits seem to drop off when students are more experienced with the material.” [5]. The results further go on to conclude that SI is most beneficial to entry level science courses such as, General Chemistry I and Organic Chemistry I. It seems as though SI is a great addition into institutions to overall help attrition rates and more generally help students improve within their courses. More research has been done to give us a wider range of knowledge on SI within Chemistry courses [9]. SI can be used to address the continuous decline of fundamental chemical knowledge noticed in recent college graduates [11].In large lecture classes, there is a disconnect between the lecturer and the student. Supplemental Instruction (SI) is often offered in a more intimate setting where the SI instructors can have one-on-one time with students to individually hone in on their specific problems, whether it is conceptual or problem-solving. As for learning environment, SI is usually held in a smaller more accommodating room where it is a less intimidating more inviting space. This setting provides a social interaction component in which usual Chemistry lectures don’t provide. In addition to the more personal tutoring time available, students are also encouraged to interact in a common social setting. This allows for an opportunity of collaborative learning and may help foster a sense of community [12].The attraction to SI in a college setting is due to its short and long-term effects. The short-term effects of SI sessions are to instill a deeper understanding of the coursework within students. Whereas the long-term goals are two-fold, the academic goal is to change the way students learn, study, and understand information so that the knowledge stays with them. Students who participate in SI earn higher grades not only the course but in subsequent semesters, which is due to improved study habits and is considered a long-term positive outcome of SI [13]. The second long-term goal is to develop better social interaction skills within these students.Many public institutions have implemented SI and thus have uncovered several significant findings. Findings that were previously mentioned pertaining to the outcomes of SI includes achieving higher percentages of passing grades [1, 14]. Some studies also found higher graduation rates among participants [1]. Despite their better performance, SI takers often score lower on academic success predictors such as the SAT and ACT exams [14]; increases in performance, therefore, appear to not occur because stronger students use SI. SI helps promote problem-solving skills because it involves the learner in the construction of knowledge and information processing based on their prior experiences which could contribute to cognitive development [15-16]. Furthermore, SI has been shown to improve motivation and enhance study habits and understanding difficult concepts [17]. Participants in SI have been found to have better control on their achievement, self-esteem, and confidence [18]. SI has also been found to higher academic self-efficacy and grades [19]. Studies have reported that students who participated in SI in introductory courses in Biology or Chemistry courses tended to continue onto upper level courses in the field; SI has a positive effect on students’ enrollment in upper level courses [20-21]. We should note that Rabitoy and co-authors reported that SI enhanced students’ achievement in STEM fields and this was greater for females and students of color [22]. METHODS While researching the topic of SI as a whole, we were able to uncover many studies that were in favor of this new implementation in institutions. Our research study is unique because it targets only at risk students and provides an added value to the curriculum. SI was implemented into The City College of New York (CCNY) as a test run in the Department of Chemistry and Biochemistry. The CCNY is an urban minority serving institute that offers a diverse selection of classes, which vary from the arts to the sciences and everything in between. We wanted to try implementing SI into the sciences to see if at risk science students can benefit from it. Grasping the S in stem, our main goal is to use the successful methods of SI to see what benefits it can bring to general science courses.Beginning during the Spring semester of 2018, SI was implemented at The CCNY’s General Chemistry I course which is composed of lecture, lab, and Peer-Led Team Learning (PLTL) workshop. PLTL is implemented as an integrated part of the course [23]. In the General Chemistry course, after exam one was distributed and grades were given back, an announcement was made introducing SI. The lecture professor would encourage students who received a failing grade, classified as a grade below a 65 out of 100 on exam one, to attend SI as means of improving in the course. This makes our study unique since we are only targeting students who are struggling the course and are not likely to earn a passing grade. It is noteworthy that PLTL offers a collaborative learning experience for all students. SI instructors targeted weaknesses in study habits, socialization, conceptual-understanding, and problem-solving skills.SI was made available for five days a week and on those days, SI was scheduled around classes times which makes it easier for students with busy schedules involving work and class to attend. During SI sessions there are instructors that have been hand-picked by instructors from a cohort of recitation leaders and who have successfully completed the course and have received a grade of A in the course. SI attendance was not mandatory.Throughout the first session available after the Supplemental Instruction announcement was made to the lecture class, those who chose to attend, because SI was not mandatory and it was strongly recommended for struggling students. Students brought their first exam with them to be discussed. This initial discussion is a one-on-one between the student and instructor, which serves as a more social component to learning whereas that isn’t available during class time. The first exam was then discussed so that the instructor can now sift through the student’s strengths and weaknesses to later target them in the weeks to come. The overall composition of our Supplementary Instruction sessions was influenced by the previous studies done and researched, hand-picking methods that seemed to work and leaving off ones that were less successful. SI sessions included cooperative learning activities, and addressed students’ misconceptions and difficulties, explored difficult concepts in depth, and enhanced problem-solving skills [24].Every week during Supplementary Instruction sessions students were encouraged to come back to further work through their weaknesses. During this trial specifically, it was noticed by the SI instructors that a lot of students actually struggle with basic problem-solving skills and reasoning. To help combat this, worksheets were made each week based on the lecture topics covered in class, based on problem-solving to help build their skills. Aside from doing the worksheets, students were encouraged to bring in topics or questions they have on the material so the SI instructors can further clarify and explain. Furthermore, students came to SI with questions that they were struggling with. Students provided questions for the SI instructor to explain which created a mutually beneficial relationship [11, 25].Our research question is: How does Supplemental Instruction in General Chemistry I impact students’ learning, conceptual understanding, retention, and attitudes?In order to properly assess how beneficial SI is to the way students learn Chemistry, data were collected at the end of the Spring and Fall of 2018 semesters, as well as Spring 2019. We used a combination Likert-type and open-ended questionnaire, as well as, grade comparisons. The Likert-type section included a five-point scale, where (1) Strongly Disagree, (2) Disagree, (3) Neutral, (4) Agree, (5) Strongly Agree. For each question, the average was taken which helps make sense of the data. For the open ended questions, questions 1 through 3, we created and used a rubric to score the questions on a scale from 1 to 5 similar to what was mentioned above. For question 4, we compiled the answers and created pie charts based on the type and number of responses.As previously stated, at the end of the semester surveys were printed and distributed to each SI session. Students that attended SI were all encouraged to participate in this survey. A total of 44 out of 60 students were available and willing to participate in the optional survey.RESULT AND DISCUSSION Graphical depictions of each Likert-type question along with average responses are shown in Figure 1. FIGURE 1. Averages for the answers for each of the Likert-type questionnaire. Our data clearly shows that students overall had a positive learning experience with SI. The students agree that SI improved their basic problem-solving skills, understanding of concepts covered, and attaining a better grade in the course. Furthermore, SI participation encouraged students to practice problems and tackle their weaknesses in the course. SI participants believe that the SI instructors targeted their weak areas and helped them improve. Finally, students felt that SI was worth the time and effort they put into it and that it was beneficial and contributed to improvements in grades.FIGURE 2. Averages of the short-answer responses were numerically scaled using a rubric.Figure 2 shows that students overall had a positive learning experience with SI and that it helped them better understand the concepts. Furthermore, the participants would enthusiastically would recommend SI to other Chemistry students.FIGURE 3. The pie chart above shows the beneficial components of SI to studentsFigure 3 shows the parts of SI that students found beneficial. Overall, there were many useful features of the SI program that facilitated students’ learning and succeeding in the course. The students appreciated the time spent on problem-solving, the flexibility of the offerings – refers to the times and days, the individualized learning experience, and the one-on-one support, guidance, and tutoring. From the Likert-type questions given in part one of the survey, responses were broken down for each given question in order to visualize the impact of SI for the students/participants. The average of the responses can be seen above and was about 4.8. The corresponding results can be viewed above as shown in Figure 1. To turn our attention to Figure 1 ‘SI has helped me to improve my basic problem solving skills’, upon meeting with the SI instructor team at The CCNY we were made aware that students have trouble with basic problem-solving which leads to the disconnect in understanding how to build upon this knowledge. When students lack this basic skill, it is difficult for them to move on and build upon this skill as the course progresses, which ultimately leads to their failure to meet the level of understanding for each lecture exam. From the responses, we can see that majority of the students feel as though their problem solving skills have developed as a result of participating in SI. Questions 6-8 deal with an overall belief about the experience of SI participation. Based on Figure 1, SI helped students better understand the course material, and had an overall positive response as 100% of students felt like they did have a better understanding of the course material after attending SI. Students overwhelmingly agree that SI is very beneficial to the way they learn Chemistry. Our data show that SI is well received by the participants which is consistent with other researchers [11]. Short answer questions 1-3 were made in order to have a more in-depth understanding of the student experience with SI this past semester. These questions were formed as short answer so students were more inclined to share their opinions of SI. The collected data shows that the students strongly agree that SI has been very beneficial for ways unique to each student. Some students enjoyed the SI instructors and their way of teaching and helping the students understand the material. While others enjoyed how personal the experience was. It wasn’t a ‘one size fits all’ experience but an experience that was personalized to each student’s needs, strengths, and weaknesses. Short answers for question 4 also had very personalized responses. Question 4 in particular – ‘What features of SI did you find to be most beneficial to you?’ was very helpful in understanding what students appreciate most about SI, and served as a standard to which should be upheld. Responses ranged from the flexible times SI was offered to the small class setting which is extremely different than the lecture, and more comfortable. Students also enjoyed and benefited from the one-on-one attention they received in SI session. For that reason, students would make time to attend the SI section of their ‘favorite instructor’. Furthermore, the individualized learning experience was appealing to SI participants. The overall goal is to get each student to understand complex concepts and if one instructor can better help someone to reach this goal; SI is a success. The overall responses show that SI is very beneficial and contributed a great deal to the way that students learn Chemistry. One main issue we have encountered during this initial phase of implementation is low number of students who self-select to participate in SI. Only about 10 percent of students who failed the first exam, participated in SI. One reason could be that students might not buy into the philosophy of SI. A second reason might be that students do not think that SI would help them better understand the content and succeed on the course. A third reason could be due to lack of motivation in these students. Another reason could be attributed to the lack of maturity in students who are taking General Chemistry I. We use the term ‘lack of maturity’ loosely in this sense to mean the lack of knowledge of how to conduct oneself in a college setting [26]. Most commonly, freshman students come straight from high school where they have not yet acquired good study techniques or methods which work best for them. These reasons combined with the hardship required to understand such complex concepts that they’re learning for the very first time can deter students. Our data show that students who participated in SI after failing the first exam achieved a success rate of about 80%. Students who failed the first exam and did not participate in SI had an 11% chance of passing the course. This data is consistent with several research in the field indicating that students who participate in SI have a higher chance of successfully completing the course with a passing grade [14, 27]. We feel these data make powerful statement for the added value of SI in General Chemistry courses and its impact on students learning and attitudes.CONCLUSION In conclusion, our research study on SI provided valuable data into students’ learning and conceptual understanding of content in General Chemistry. Furthermore, our findings provide insights into students’ attitudes about SI implementation and its benefits to the participants. Our research data supports the introduction of SI into General Chemistry courses and provides students with learning skills, socialization competencies, problem-solving skills, and the knowledge required to successfully complete the course. We believe that our data supports the notion that SI had a significantly affected the participants grades in a positive manner and it should be noted that that majority of SI participants earned a passing grade in the course. Our results and data on the implementation of SI in General Chemistry courses improved students’ attitudes towards the subject matter, learning, socialization, and study habits. We are confident we can reach a larger population and improve our recruitment so more students can experience SI and increase their chances of successful completion of the course. As an implication for curriculum, we would recommend supplemental instruction for all introductory courses STEM fields. ACKNOWLEDGMENT We also would like to thank the Department of Psychology at the CCNY and CUNY Coordinated Undergraduate Education (CUE) for funding our Supplemental Instruction program.

Abstract A method is proposed to analyze the modal damping in mistuned bladed-disk with root joints using large finite element models and the detailed description of frictional interactions at contact interfaces. The influence of mistuning on the dissipated energy for different blades on a bladed-disk and the modal damping factors for different vibration levels for any family of modes can be investigated. The dissipated energy and damping factors due to microslip are simulated by multitude of surface-to-surface elements modeling the friction contact interactions at root joints. The analysis is performed in the time domain, and an original reduction method is developed to obtain the results with acceptable computational times. The model reduction method allows the calculation of the modal damping of the mistuned assembly by evaluation of the energy dissipated at root joint of each individual blade using small parts of bladed disk sectors. The dependency of modal damping factor on blade mode shapes, engine-order excitation numbers, nodal diameter numbers, and vibration amplitudes is studied and the distributions of amplitude and dissipated energy on the mistuned bladed-disk are investigated using a realistic blade disk model.

Abstract The effect of differences in nominally equal sectors of a bladed disk (mistuning) is a well-known problem for designers since the forced response may show localized amplification of the blade response with respect to a cyclically symmetric (tuned) configuration. In order to perform a large number of simulations in a reasonable amount of time to characterize the highest blade response, corresponding to the worst mistuning pattern, reduction techniques have been developed where mistuning is introduced directly in Reduced Order Models (ROM) obtained from very large finite element (FE) models. Typically, mistuning is introduced in the ROM in terms of natural frequency perturbations of the blade; nevertheless, a better insight is required to correlate mistuning to a specific source (geometrical, material, contact mistuning). In this paper, a reduction technique is presented to take into account mistuning due to the contact uncertainties at the blade root joint, which can be caused by design tolerances, manufacturing process, assembly procedures, wear. The technique takes its basis from the Craig-Bampton Component Mode Synthesis applied to the uncoupled blade and disk sector, which is typically included in most of the FE software for an easy implementation in standard industrial practice. The set of master degrees of freedom at the random contacts are purposely reduced using an optimal local modal basis based on the Gram-Schmidt Interface technique developed by the authors. Experimental evidence of actual uncertain contacts obtained during joint pre-loading is used to find an appropriate base to represent typical contact patterns.

Emphasis of this article is on the dynamic characteristics analysis of individual pitch control for MW scale directly driven wind turbines with permanent magnet synchronous generator (PMSG). The pitch control objectives were analyzed and the objective expressions were deduced, including power expression, loads expression, and vibration expressions of blade and tower. Then, both the collective pitch control aiming at power control and the individual pitch control strategy aiming at joint power and loads control were analyzed, too. The blade root bending moments and the actual capture power of wind rotor were employed to be the control variables. The power was calculated based on the conventional measured parameters of wind turbines. In order to reflect the difference between the pitch angle command value and the actual value, the pitch actuator dynamic model was used. The research results show that both the collective pitch control strategy and the proposed individual pitch control strategy can effectively control the power injected into grid; moreover, the individual pitch control can reduce fatigue loads; while in the process of individual pitch control, the actual variation of blade pitch angle is closely related to not only the inflow speed but also the blade azimuth angle; individual pitch control strategy can reduce the variation amplitude of flapwise moments, but has little influence on the edgewise moments.

A method for the analysis of amplitude-dependent modal damping factors is developed for the cases when the energy dissipation is caused by the micro-slip motion at friction contacts of blade root joints. The modal damping at root joints for a lone blade and for tuned bladed disc assemblies is studied. Large three-dimensional finite element models and detailed description of friction contacts by surface-to-surface friction contact elements at contact interfaces of the root joints are used for the calculations. The method allows using available finite element packages and is based on the direct calculation of the energy dissipated at root joints for prescribed levels of vibration amplitudes. The method takes into account the nonlinear dependency of the modal damping factors on the vibration level. The numerical studies of the dependency of modal damping factors on the vibration amplitudes, rotation speed, and contact interface parameters are performed for different families of modes and different nodal diameter numbers.

The prediction of extreme loads for the offshore floating wind turbine is analyzed based on the inverse reliability technique. The inverse reliability approach is in general used to establish the design levels associated with the specified probability of failure. The present study is performed using the environmental contour (EC) method to estimate the long-term joint probability distribution of extreme loads for different types of offshore floating wind turbines. The analysis is carried out in order to predict the out-of-plane bending moment (OoPBM) loads at the blade root and tower base moment (TBM) loads for a 5 MW offshore floating wind turbine of different floater configuration. The spar-type and semisubmersible type offshore floating wind turbines are considered for the analysis. The FAST code is used to simulate the wind conditions for various return periods and the design loads of various floating wind turbine configurations. The extreme and operation situation of the spar-type and semisubmersible type offshore floating wind turbine are analyzed using one-dimensional (1D) and two-dimensional (2D)-EC methods for different return periods. The study is useful to predict long-term design loads for offshore wind turbines without requiring excessive computational effort.

Abstract The design of disk assemblies requires the capability to predict their dynamic behavior. To achieve this objective, knowledge of friction damping on the contact between blade and disk is of paramount importance. This paper proposes an experimental technique to measure the loss factor and the dynamics, in terms of natural frequencies, of blade-disk attachment. The free decay is used to infer the dynamic parameters from dummy blades. The identification method is based on the Hilbert transform that al-lows extracting the dynamic parameters from non-linear system. This paper shows the test rig utilized in the experimental analysis and details the excitation system used to displace the dummy blade. This system must be a real or a "virtual" non-contact system to avoid injecting external damping into the blade under test. Tests were performed on both a dovetail and a fir-tree type attachments. On the dovetail, tests were performed both with dry contact surfaces and with contact surfaces covered by a film of lubricant to achieve a low coefficient of friction. This low coefficient of friction better simulates dry surfaces at high temperatures, as friction coefficients decrease with temperatures. This paper presents the results obtained on the first and second bending mode. The experimental results show the loss factor and the natural frequency for different axial loads. The measured loss factor depends on the amplitude of vibrations. The loss factor shows a maximum then approaching zero for large amplitude of vibrations and it decreases with increasing centrifugal loads.

A new effective method for comprehensive modeling of gas flow effects on vibration of nonlinear vibration of bladed disks has been developed for a case when the effect of the gas flow on the mode shapes is significant. The method separates completely the structural dynamics calculations from the significantly more computationally expensive computational fluid dynamics (CFD) calculations while providing the high accuracy of modeling for aerodynamic effects. A comprehensive analysis of the forced response using the new method has been performed for a realistic turbine bladed disk with root-disk joints, tip, and under-platform dampers. The full chain of aerodynamic and structural calculations are performed: (i) determination of boundary conditions for CFD, (ii) CFD analysis, (iii) calculation of the aerodynamic characteristics required by the new method, and (iv) nonlinear forced response analysis using the modal aerodynamic influence matrix (MAIM). The efficiency of the friction damping devices has been studied and compared for several resonance frequencies and engine orders. Advantages of the method for aerodynamic effect modeling have been demonstrated.

Cars crest the rise behind the truck stop and drop cones of light over the highway. Ryan dunks his head under a tap. He rubs red dust from his pores and tries to drink some water, but it slides down his throat like a length of wire.His older brother Josh fills their drink bottles. “Wanna get some chips or something?”Ryan shakes his head. He’s sick of watching Josh’s pulpy tongue poke his broken tooth. Their dad never left visible marks before—Ryan used to wish for a cut or bruise, so someone at school could see it. He shivers and clutches his coat tight. Josh says, “We got money.”Ryan wonders how Josh stole it. He didn’t know there was anything to steal. He stares back down the road.“Fine, fuck, I’ll get—”Ryan nudges him and he looks over his shoulder. A square silhouette approaches. The brothers stand back as a two-storey house pulls up in front of them, strapped to the back of a truck. The house is cut in half, patched with pale afterimages of furniture and light fittings. A door slams and a tattooed man with a white wedge of beard climbs out of the cabin. He stretches and heads for the toilets. Josh sidles up to the house and runs his hands along the straight, fresh edge of the floorboards. Sawdust settles onto his hoodie. He laughs and hurls his bag into one of the rooms. “Shit yeah. You coming?” Ryan hesitates. He remembers the time Josh’s Torana—a windowless wreck, used for drifting in paddocks and chasing kangaroos—broke down at the back of their property. Ryan and their dad towed Josh in the four-wheel drive while he sat in the Torana, steering with his knees. He started swinging wide, bouncing the back of the car off tree trunks, until he overshot and hit an old gum headfirst. The cable snapped, jerking the four-wheel drive to a halt. Ryan’s head smacked against the dash. Josh emerged from the smoking Torana with a bloody nose, laughing hysterically—thumping the bonnet and laughing hysterically—even after his dad came over and hit him on the back of the head. Through a window in the far wall they watch the driver eat a sausage roll. Ryan follows Josh upstairs and they stand on the edge of the second floor, where the distorted acoustics amplify the traffic sounds. From this angle, the outback barely conceals the curvature of the earth. The moon is a globe of bone amongst the clouds, a ball and socket. Ryan thinks they’re in a kid’s bedroom; a mural on the far wall depicts the bottom of the ocean and a tinted window spreads faded colours on the floor. He tries to imagine the room with all its walls in place. The brothers hide in a back room when they hear the driver's footsteps. The driver slides a torch over the house and light filters through the floorboards in front of them. They press themselves against the wall. Ryan starts shivering again and Josh elbows him in the ribs. The truck eases onto the road and the house groans, its unsupported floorboards dipping and lifting like piano keys. Signs and lights flick past. The brothers creep downstairs, struggling to stay upright on the vibrating staircase. Josh opens two tins of baked beans. A string of cold sauce as thick as an artery spills down Ryan’s neck. They place the empty tins on the floor and bet on which one will roll off the edge first. Josh wins. He grabs Ryan’s head and rubs his knuckles into it. Josh runs into the bathroom, which juts out over the edge of the trailer. Ryan hangs back in the doorway. Instead of a toilet Josh finds a small circle cut out of the floor. He steadies himself and pisses in it. Ryan sprints into the other room and pisses out the window. They laugh and piss until a horn blares behind them. Ryan ducks. Urine splatters on the sill. He scrabbles with his pants. He’s pissed on someone’s windscreen. The horn’s still going. Headlights hit the trees beside him. Josh comes in from the toilet and Ryan grabs him and pulls him to the ground. A four-wheel drive appears beside them. There’s barely enough room on the road; the truck swerves away and a branch scrapes along the roof of the house. The passengers hang out the windows, screaming abuse. Josh stumbles onto his feet and gives them the finger. Someone hurls an empty coke can and it lands on the second floor. Then the car is gone and only the wind remains, filling the house with the whining roar of a depressurised aircraft. The trees are a smear of static. Josh smacks Ryan on the back of the head. Ryan swings instinctively. Josh deflects his fist and knocks him to the floor and Ryan’s head hits the skirting board. Something crumbles. Ryan presses his thumb into Josh’s black eye and Josh twists his arm behind his back. When they were kids Josh pinned Ryan in this position and shoved gravel into his mouth. Ryan remembers the stones scratching his teeth, the bloody mud he spat out. Josh lets him up and Ryan scrambles into the corner, sick with sudden panic. He kicks his bag away. Josh wipes his mouth and laughs. He crouches down and stares at the spot where Ryan’s head hit the wall. One of the panels has collapsed inwards. Josh snorts. “Look what your fucking head did!” He pulls out the panel and tosses it onto the road. He shines his torch into the space behind it, brushes away the cobwebs and extracts a cheap gold box. “Well, well, well,” he mutters. He sets it on the ground and dusts the lid off. He tries to pry it open it but it’s locked. Ryan looks over. Josh grips the box in both hands and pulls. For a moment his top teeth dig into his lip and then the box bursts open, scattering pieces of silver. Ryan reaches out his hand, expecting jewellery, but he jerks it back when he finds a razor near his foot. The floor is littered with needles and knives. Josh picks up a brown glass bottle and squints at the label. “Iodine.” They stare at the blades in silence. A sand bank slides past as steadily as a sine wave. Josh carves the word FUCK into the floor with a scalpel. Ryan cringes but doesn’t dare warn him about diseases. On long-distance drives Ryan often stares out the window and imagines his vision is a laser-beam, cutting cleanly through cities, forests, passers-by. Now he pictures a wrecking ball swinging into the darkness and colliding with a run-down rollercoaster. He imagines the ball smashing through the tangle of struts and tracks; wrapping around and around a corkscrew section like a yoyo; sending a train of carriages hurtling through the remains of a loop. A few hours later the house passes through a town surrounded by silos and steel windmills. The brothers retreat to the mural room. Streetlights slide on and off them: orange, black, orange, black, orange, black. Josh waves at the people on the balcony of the pub. In a slouched house over a hardware store Ryan glimpses, through half-closed curtains, a topless woman sitting on the edge of a bed, combing her hair. He tries to make out the name of the town on the shopfronts. Josh lights a joint, indifferent. Ryan slides his torch over the door frame, which is marked with the family’s heights. The vibrations blur the words, but he makes out the name “Molly” at eye level. He wonders if this is her room. He stares at the underwater scene and remembers reading somewhere that squids lay eggs via a funnel under their eyes, so their offspring emerge like hard, heavy tears. Josh offers the joint to Ryan, who snatches it and takes a shallow drag. Josh brushes dandruff off his sleeves. Ryan drops the joint when a siren starts to wail: they scramble to their feet and run over to the back window, fearing the police, but the road’s empty. Josh looks up and shouts, “Smoke detector!” Ryan starts waving his jacket to clear the smoke, but Josh just rips the detector from the ceiling and hurls it into a dam beside the road. Once the houses thin out the brothers climb back downstairs and unroll their sleeping bags. Ryan uses his pack as a pillow but Josh’s is still full of tins. Dark branches clasp the stars. Ryan gets up and tugs at his penis in the toilet, watching the bitumen slide under the hole like a belt sander. He tries to remember the scene above the hardware store—the line of tea lights on the windowsill, the mosquito net over the bed, the woman’s small, pale breasts—but his mind keeps replaying the image of a young girl pressing a razor into her thigh. They're woken a few hours later by footsteps. Ryan opens his eyes. Josh is already on his feet. “What the hell is that?” The ceiling creaks again and Josh picks up the torch and the scalpel. “I'm gonna take a look.” They creep upstairs. The hall is empty. Something shuffles in one of the rooms and slams against the wall. Josh whispers, “There ain’t no doors on that side of the hall. The fucking door's in the other half of the house.' He grabs the end of the wall and leans out, struggling to see around it. The wind blasts him back and he cups his hands over his black eye. He pushes the torch into Ryan’s chest. “Go. You go.” Ryan tries to turn away but Josh blocks him and says, “Don’t be a dickhead. Just see what’s over there.” The dark, crinkled skin around his eye shines with tears. “Fuck’s sake, my eye’s killing me. I can’t go.” He pushes Ryan again. With his free hand Ryan feels for the frame behind the plaster. He swings his leg around the wall, plants his foot on the other side, presses his chest against the end of the wall and edges into the other room. It’s empty. Sliding doors in the far wall conceal a walk-in wardrobe. A door on the right leads to an en suite. His foot crunches on the coke can and he kicks it onto the road. He pushes the bathroom door open and the torch beam slides over the tiles. He glimpses movement behind him in the mirror, but it’s only the trees. The tiles remind him of the killing floor on their chicken farm. When he and Josh were little their dad just cut the chickens’ heads off with an axe and let them run around spurting blood out of their necks, but a few years ago he got new machinery installed. Now the chickens were strung up by their feet on an overhead conveyor belt that carried them to a trough filled with electrified water, which killed them as soon as their heads hit it. He walks back into the bedroom and stares at the sliding doors. “Oi hurry up!” Josh shouts from the hall. “Fuck you.” “Fuck you, dickhead!” Ryan pushes a sliding door open and shines his torch in. A man crouches in the darkness, gripping a bottle of colourless liquid in both hands. His clothes are stuffed with newspapers; his beard clings to his chin like clotted blood caked together. He stares at Ryan and shouts, “Bastards! Leave me alone ya bastards! Get outta here! Get out!” He hurls the bottle and it smacks into Ryan’s shoulder. The bottle smashes on the floor; shards of glass cascade onto the highway. The man stumbles out of the wardrobe, lunging at Ryan, grabbing at his jacket. Ryan reaches around the wall and Josh pulls him over. The man slams his fists rhythmically, like pistons, into the other side of the wall. They scramble downstairs and Ryan takes off his jacket and waves it over the edge, screaming to get the driver’s attention. He looks up and sees the man shouting at him, tears streaming sideways across his face. Josh pulls Ryan back but he struggles free. Ryan crouches near the edge and stares at the scrub racing past. There’s a hill ahead and the truck’s slowing down. Josh sees what he’s thinking and calls him an idiot, but he’s already leaning forwards, judging the distance, waiting for the driver to downshift. Josh grabs him by the collar and hisses something but he doesn’t listen and pulls away and jumps. His head smacks solidly against a root and his arm twists under his torso, grinding into the gravel. He lies on his back and spits out black dust. Blood dribbles out of his arm. When the house reaches the top of the hill something flies out and bounces along the side of the road. Ryan gets to his feet and limps towards it. He searches through the bushes and finds his bag with half the tins in it. The roof of the house disappears over the top of the hill and he imagines Josh reaching his destination, perhaps a few hours after dawn, on a small hill out in the bush somewhere, where the morning light is as sallow as blood plasma and the other half of the house is already waiting.

“...children’s play seems to become more and more a product of the educational and cultural orientation of parents...” — Stephen Kline, The Making of Children’s Culture We live in a world saturated by design and through design artefacts, one can glean unique insights into a culture's values and norms. In fact, some academics, such as British media and film theorist Ben Highmore, see the two areas so inextricably intertwined as to suggest a wholesale “re-branding of the cultural sciences as design studies” (14). Too often, however, everyday objects are marginalised or overlooked as objects of scholarly attention. The field of material culture studies seeks to change that by focussing on the quotidian object and its ability to reveal much about the time, place, and culture in which it was designed and used. This article takes on one such object, a mid-century children's toy tea set, whose humble journey from 1968 Sears catalogue to 2014 thrift shop—and subsequently this author’s basement—reveals complex rhetorical messages communicated both visually and verbally. As material culture studies theorist Jules Prown notes, the field’s foundation is laid upon the understanding “that objects made ... by man reflect, consciously or unconsciously, directly or indirectly, the beliefs of individuals who made, commissioned, purchased or used them, and by extension the beliefs of the larger society to which they belonged” (1-2). In this case, the objects’ material and aesthetic characteristics can be shown to reflect some of the pervasive stereotypes and gender roles of the mid-century and trace some of the prevailing tastes of the American middle class of that era, or perhaps more accurately the type of design that came to represent good taste and a modern aesthetic for that audience. A wealth of research exists on the function of toys and play in learning about the world and even the role of toy selection in early sex-typing, socialisation, and personal identity of children (Teglasi). This particular research area isn’t the focus of this article; however, one aspect that is directly relevant and will be addressed is the notion of adult role-playing among children and the role of toys in communicating certain adult practices or values to the child—what sociologist David Oswell calls “the dedifferentiation of childhood and adulthood” (200). Neither is the focus of this article the practice nor indeed the ethicality of marketing to children. Relevant to this particular example I suggest, is as a product utilising messaging aimed not at children but at adults, appealing to certain parents’ interest in nurturing within their child a perceived era and class-appropriate sense of taste. This was fuelled in large part by the curatorial pursuits of the Museum of Modern Art (MoMA) in New York, coupled with an interest and investment in raising their children in a design-forward household and a desire for toys that reflected that priority; in essence, parents wishing to raise modern children. Following Prown’s model of material culture analysis, the tea set is examined in three stages, through description, deduction and speculation with each stage building on the previous one. Figure 1: Porcelain Toy Tea Set. Description The tea set consists of twenty-six pieces that allows service for six. Six cups, saucers, and plates; a tall carafe with spout, handle and lid; a smaller vessel with a spout and handle; a small round bowl with a lid; a larger oval bowl with a lid, and a coordinated oval platter. The cups are just under two inches tall and two inches in diameter. The largest piece, the platter is roughly six inches by four inches. The pieces are made of a ceramic material white in colour and glossy in texture and are very lightweight. The rim or edge of each piece is decorated with a motif of three straight lines in two different shades of blue and in different thicknesses, interspersed with a set of three black wiggly lines. Figure 2: Porcelain Toy Tea Set Box. The set is packaged for retail purposes and the original box appears to be fully intact. The packaging of an object carries artefactual evidence just as important as what it contains that falls into the category of a “‘para-artefact’ … paraphernalia that accompanies the product (labels, packaging, instructions etc.), all of which contribute to a product’s discourse” (Folkmann and Jensen 83). The graphics on the box are colourful, featuring similar shades of teal blue as found on the objects, with the addition of orange and a silver sticker featuring the logo of the American retailer Sears. The cover features an illustration of the objects on an orange tabletop. The most prominent text that confirms that the toy is a “Porcelain Toy Tea Set” is in an organic, almost psychedelic style that mimics both popular graphics of this era—especially album art and concert posters—as well as the organic curves of steam that emanate from the illustrated teapot’s spout. Additional messages appear on the box, in particular “Contemporary DESIGN” and “handsome, clean-line styling for modern little hostesses”. Along the edges of the box lid, a detail of the decorative motif is reproduced somewhat abstracted from what actually appears on the ceramic objects. Figure 3: Sears’s Christmas Wishbook Catalogue, page 574 (1968). Sears, Roebuck and Co. (Sears) is well-known for its over one-hundred-year history of producing printed merchandise catalogues. The catalogue is another important para-artefact to consider in analysing the objects. The tea set first appeared in the 1968 Sears Christmas Wishbook. There is no date or copyright on the box, so only its inclusion in the catalogue allows the set to be accurately dated. It also allows us to understand how the set was originally marketed. Deduction In the deduction phase, we focus on the sensory aesthetic and functional interactive qualities of the various components of the set. In terms of its function, it is critical that we situate the objects in their original use context, play. The light weight of the objects and thinness of the ceramic material lends the objects a delicate, if not fragile, feeling which indicates that this set is not for rough use. Toy historian Lorraine May Punchard differentiates between toy tea sets “meant to be used by little girls, having parties for their friends and practising the social graces of the times” and smaller sets or doll dishes “made for little girls to have parties with their dolls, or for their dolls to have parties among themselves” (7). Similar sets sold by Sears feature images of girls using the sets with both human playmates and dolls. The quantity allowing service for six invites multiple users to join the party. The packaging makes clear that these toy tea sets were intended for imaginary play only, rendering them non-functional through an all-capitals caution declaiming “IMPORTANT: Do not use near heat”. The walls and handles of the cups are so thin one can imagine that they would quickly become dangerous if filled with a hot liquid. Nevertheless, the lid of the oval bowl has a tan stain or watermark which suggests actual use. The box is broken up by pink cardboard partitions dividing it into segments sized for each item in the set. Interestingly even the small squares of unfinished corrugated cardboard used as cushioning between each stacked plate have survived. The evidence of careful re-packing indicates that great care was taken in keeping the objects safe. It may suggest that even though the set was used, the children or perhaps the parents, considered the set as something to care for and conserve for the future. Flaws in the glaze and applique of the design motif can be found on several pieces in the set and offer some insight as to the technique used in producing these items. Errors such as the design being perfectly evenly spaced but crooked in its alignment to the rim, or pieces of the design becoming detached or accidentally folded over and overlapping itself could only be the result of a print transfer technique popularised with decorative china of the Victorian era, a technique which lends itself to mass production and lower cost when compared to hand decoration. Speculation In the speculation stage, we can consider the external evidence and begin a more rigorous investigation of the messaging, iconography, and possible meanings of the material artefact. Aspects of the set allow a number of useful observations about the role of such an object in its own time and context. Sociologists observe the role of toys as embodiments of particular types of parental messages and values (Cross 292) and note how particularly in the twentieth century “children’s play seems to become more and more a product of the educational and cultural orientation of parents” (Kline 96). Throughout history children’s toys often reflected a miniaturised version of the adult world allowing children to role-play as imagined adult-selves. Kristina Ranalli explored parallels between the practice of drinking tea and the play-acting of the child’s tea party, particularly in the nineteenth century, as a gendered ritual of gentility; a method of socialisation and education, and an opportunity for exploratory and even transgressive play by “spontaneously creating mini-societies with rules of their own” (20). Such toys and objects were available through the Sears mail-order catalogue from the very beginning at the end of the nineteenth century (McGuire). Propelled by the post-war boom of suburban development and homeownership—that generation’s manifestation of the American Dream—concern with home décor and design was elevated among the American mainstream to a degree never before seen. There was a hunger for new, streamlined, efficient, modernist living. In his essay titled “Domesticating Modernity”, historian Jeffrey L. Meikle notes that many early modernist designers found that perhaps the most potent way to “‘domesticate’ modernism and make it more familiar was to miniaturise it; for example, to shrink the skyscraper and put it into the home as furniture or tableware” (143). Dr Timothy Blade, curator of the 1985 exhibition of girls’ toys at the University of Minnesota’s Goldstein Gallery—now the Goldstein Museum of Design—described in his introduction “a miniaturised world with little props which duplicate, however rudely, the larger world of adults” (5). Noting the power of such toys to reflect adult values of their time, Blade continues: “the microcosm of the child’s world, remarkably furnished by the miniaturised props of their parents’ world, holds many direct and implied messages about the society which brought it into being” (9). In large part, the mid-century Sears catalogues capture the spirit of an era when, as collector Thomas Holland observes, “little girls were still primarily being offered only the options of glamour, beauty and parenthood as the stuff of their fantasies” (175). Holland notes that “the Wishbooks of the fifties [and, I would add, the sixties] assumed most girls would follow in their mother’s footsteps to become full-time housewives and mommies” (1). Blade grouped toys into three categories: cooking, cleaning, and sewing. A tea set could arguably be considered part of the cooking category, but closer examination of the language used in marketing this object—“little hostesses”, et cetera—suggests an emphasis not on cooking but on serving or entertaining. This particular category was not prevalent in the era examined by Blade, but the cultural shifts of the mid-twentieth century, particularly the rapid popularisation of a suburban lifestyle, may have led to the use of entertaining as an additional distinct category of role play in the process of learning to become a “proper” homemaker. Sears and other retailers offered a wide variety of styles of toy tea sets during this era. Blade and numerous other sources observe that children’s toy furniture and appliances tended to reflect the style and aesthetic qualities of their contemporary parallels in the adult world, the better to associate the child’s objects to its adult equivalent. The toy tea set’s packaging trumpets messages intended to appeal to modernist values and identity including “Contemporary Design” and “handsome, clean-line styling for modern little hostesses”. The use of this coded marketing language, aimed particularly at parents, can be traced back several decades. In 1928 a group of American industrial and textile designers established the American Designers' Gallery in New York, in part to encourage American designers to innovate and adopt new styles such as those seen in the L’ Exposition Internationale des Arts Decoratifs et Industriels Modernes (1925) in Paris, the exposition that sparked international interest in the Art Deco or Art Moderne aesthetic. One of the gallery founders, Ilonka Karasz, a Hungarian-American industrial and textile designer who had studied in Austria and was influenced by the Wiener Werkstätte in Vienna, publicised her new style of nursery furnishings as “designed for the very modern American child” (Brown 80). Sears itself was no stranger to the appeal of such language. The term “contemporary design” was ubiquitous in catalogue copy of the nineteen-fifties and sixties, used to describe everything from draperies (1959) and bedspreads (1961) to spice racks (1964) and the Lady Kenmore portable dishwasher (1961). An emphasis on the role of design in one’s life and surroundings can be traced back to efforts by MoMA. The museum’s interest in modern design hearkens back almost to the institution’s inception, particularly in relation to industrial design and the aestheticisation of everyday objects (Marshall). Through exhibitions and in partnership with mass-market magazines, department stores and manufacturer showrooms, MoMA curators evangelised the importance of “good design” a term that can be found in use as early as 1942. What Is Good Design? followed the pattern of prior exhibitions such as What Is Modern Painting? and situated modern design at the centre of exhibitions that toured the United States in the first half of the nineteen-fifties. To MoMA and its partners, “good design” signified the narrow identification of proper taste in furniture, home decor and accessories; effectively, the establishment of a design canon. The viewpoints enshrined in these exhibitions and partnerships were highly influential on the nation’s perception of taste for decades to come, as the trickle-down effect reached a much broader segment of consumers than those that directly experienced the museum or its exhibitions (Lawrence.) This was evident not only at high-end shops such as Bloomingdale’s and Macy’s. Even mass-market retailers sought out well-known figures of modernist design to contribute to their offerings. Sears, for example, commissioned noted modernist designer and ceramicist Russel Wright to produce a variety of serving ware and decor items exclusively for the company. Notably for this study, he was also commissioned to create a toy tea set for children. The 1957 Wishbook touts the set as “especially created to delight modern little misses”. Within its Good Design series, MoMA exhibitions celebrated numerous prominent Nordic designers who were exploring simplified forms and new material technologies. In the 1968 Wishbook, the retailer describes the Porcelain Toy Tea Set as “Danish-inspired china for young moderns”. The reference to Danish design is certainly compatible with the modernist appeal; after the explosion in popularity of Danish furniture design, the term “Danish Modern” was commonly used in the nineteen-fifties and sixties as shorthand for pan-Scandinavian or Nordic design, or more broadly for any modern furniture design regardless of origin that exhibited similar characteristics. In subsequent decades the notion of a monolithic Scandinavian-Nordic design aesthetic or movement has been debunked as primarily an economically motivated marketing ploy (Olivarez et al.; Fallan). In the United States, the term “Danish Modern” became so commonly misused that the Danish Society for Arts and Crafts called upon the American Federal Trade Commission (FTC) to legally restrict the use of the labels “Danish” and “Danish Modern” to companies genuinely originating in Denmark. Coincidentally the FTC ruled on this in 1968, noting “that ‘Danish Modern’ carries certain meanings, and... that consumers might prefer goods that are identified with a foreign culture” (Hansen 451). In the case of the Porcelain Toy Tea Set examined here, Sears was not claiming that the design was “Danish” but rather “Danish-inspired”. One must wonder, was this another coded marketing ploy to communicate a sense of “Good Design” to potential customers? An examination of the formal qualities of the set’s components, particularly the simplified geometric forms and the handle style of the cups, confirms that it is unlike a traditional—say, Victorian-style—tea set. Punchard observes that during this era some American tea sets were actually being modelled on coffee services rather than traditional tea services (148). A visual comparison of other sets sold by Sears in the same year reveals a variety of cup and pot shapes—with some similar to the set in question—while others exhibit more traditional teapot and cup shapes. Coffee culture was historically prominent in Nordic cultures so there is at least a passing reference to that aspect of Nordic—if not specifically Danish—influence in the design. But what of the decorative motif? Simple curved lines were certainly prominent in Danish furniture and architecture of this era, and occasionally found in combination with straight lines, but no connection back to any specific Danish motif could be found even after consultation with experts in the field from the Museum of Danish America and the Vesterheim National Norwegian-American Museum (personal correspondence). However, knowing that the average American consumer of this era—even the design-savvy among them—consumed Scandinavian design without distinguishing between the various nations, a possible explanation could be contained in the promotion of Finnish textiles at the time. In the decade prior to the manufacture of the tea set a major design tendency began to emerge in the United States, triggered by the geometric design motifs of the Finnish textile and apparel company Marimekko. Marimekko products were introduced to the American market in 1959 via the Cambridge, Massachusetts-based retailer Design Research (DR) and quickly exploded in popularity particularly after would-be First Lady Jacqueline Kennedy appeared in national media wearing Marimekko dresses during the 1960 presidential campaign and on the cover of Sports Illustrated magazine. (Thompson and Lange). The company’s styling soon came to epitomise a new youth aesthetic of the early nineteen sixties in the United States, a softer and more casual predecessor to the London “mod” influence. During this time multiple patterns were released that brought a sense of whimsy and a more human touch to classic mechanical patterns and stripes. The patterns Piccolo (1953), Helmipitsi (1959), and Varvunraita (1959), all designed by Vuokko Eskolin-Nurmesniemi offered varying motifs of parallel straight lines. Maija Isola's Silkkikuikka (1961) pattern—said to be inspired by the plumage of the Great Crested Grebe—combined parallel serpentine lines with straight and angled lines, available in a variety of colours. These and other geometrically inspired patterns quickly inundated apparel and decor markets. DR built a vastly expanded Cambridge flagship store and opened new locations in New York in 1961 and 1964, and in San Francisco in 1965 fuelled in no small part by the fact that they remained the exclusive outlet for Marimekko in the United States. It is clear that Marimekko’s approach to pattern influenced designers and manufacturers across industries. Design historian Lesley Jackson demonstrates that Marimekko designs influenced or were emulated by numerous other companies across Scandinavia and beyond (72-78). The company’s influence grew to such an extent that some described it as a “conquest of the international market” (Hedqvist and Tarschys 150). Subsequent design-forward retailers such as IKEA and Crate and Barrel continue to look to Marimekko even today for modern design inspiration. In 2016 the mass-market retailer Target formed a design partnership with Marimekko to offer an expansive limited-edition line in their stores, numbering over two hundred items. So, despite the “Danish” misnomer, it is quite conceivable that designers working for or commissioned by Sears in 1968 may have taken their aesthetic cues from Marimekko’s booming work, demonstrating a clear understanding of the contemporary high design aesthetic of the time and coding the marketing rhetoric accordingly even if incorrectly. Conclusion The Sears catalogue plays a unique role in capturing cross-sections of American culture not only as a sales tool but also in Holland’s words as “a beautifully illustrated diary of America, it’s [sic] people and the way we thought about things” (1). Applying a rhetorical and material culture analysis to the catalogue and the objects within it provides a unique glimpse into the roles these objects played in mediating relationships, transmitting values and embodying social practices, tastes and beliefs of mid-century American consumers. Adult consumers familiar with the characteristics of the culture of “Good Design” potentially could have made a connection between the simplified geometric forms of the components of the toy tea set and say the work of modernist tableware designers such as Kaj Franck, or between the set’s graphic pattern and the modernist motifs of Marimekko and its imitators. But for a much broader segment of the population with a less direct understanding of modernist aesthetics, those connections may not have been immediately apparent. The rhetorical messaging behind the objects’ packaging and marketing used class and taste signifiers such as modern, contemporary and “Danish” to reinforce this connection to effect an emotional and aspirational appeal. These messages were coded to position the set as an effective transmitter of modernist values and to target parents with the ambition to create “appropriately modern” environments for their children. References Ancestry.com. “Historic Catalogs of Sears, Roebuck and Co., 1896–1993.” <http://search.ancestry.com/search/db.aspx?dbid=1670>. Baker Furniture Inc. “Design Legacy: Our Story.” n.d. <http://www.bakerfurniture.com/design-story/ legacy-of-quality/design-legacy/>. Blade, Timothy Trent. “Introduction.” Child’s Play, Woman’s Work: An Exhibition of Miniature Toy Appliances: June 12, 1985–September 29, 1985. St. Paul: Goldstein Gallery, U Minnesota, 1985. Brown, Ashley. “Ilonka Karasz: Rediscovering a Modernist Pioneer.” Studies in the Decorative Arts 8.1 (2000-1): 69–91. Cross, Gary. “Gendered Futures/Gendered Fantasies: Toys as Representatives of Changing Childhood.” American Journal of Semiotics 12.1 (1995): 289–310. Dolansky, Fanny. “Playing with Gender: Girls, Dolls, and Adult Ideals in the Roman World.” Classical Antiquity 31.2 (2012): 256–92. Fallan, Kjetil. Scandinavian Design: Alternative Histories. Berg, 2012. Folkmann, Mads Nygaard, and Hans-Christian Jensen. “Subjectivity in Self-Historicization: Design and Mediation of a ‘New Danish Modern’ Living Room Set.” Design and Culture 7.1 (2015): 65–84. Hansen, Per H. “Networks, Narratives, and New Markets: The Rise and Decline of Danish Modern Furniture Design, 1930–1970.” The Business History Review 80.3 (2006): 449–83. Hedqvist, Hedvig, and Rebecka Tarschys. “Thoughts on the International Reception of Marimekko.” Marimekko: Fabrics, Fashions, Architecture. Ed. Marianne Aav. Bard. 2003. 149–71. Highmore, Ben. The Design Culture Reader. Routledge, 2008. Holland, Thomas W. Girls’ Toys of the Fifties and Sixties: Memorable Catalog Pages from the Legendary Sears Christmas Wishbooks, 1950-1969. Windmill, 1997. Hucal, Sarah. "Scandi Crush Saga: How Scandinavian Design Took over the World." Curbed, 23 Mar. 2016. <http://www.curbed.com/2016/3/23/11286010/scandinavian-design-arne-jacobsen-alvar-aalto-muuto-artek>. Jackson, Lesley. “Textile Patterns in an International Context: Precursors, Contemporaries, and Successors.” Marimekko: Fabrics, Fashions, Architecture. Ed. Marianne Aav. Bard. 2003. 44–83. Kline, Stephen. “The Making of Children’s Culture.” The Children’s Culture Reader. Ed. Henry Jenkins. New York: NYU P, 1998. 95–109. Lawrence, Sidney. “Declaration of Function: Documents from the Museum of Modern Art’s Design Crusade, 1933-1950.” Design Issues 2.1 (1985): 65–77. Marshall, Jennifer Jane. Machine Art 1934. Chicago: U of Chicago P, 2012. McGuire, Sheila. “Playing House: Sex-Roles and the Child’s World.” Child’s Play, Woman’s Work: An Exhibition of Miniature Toy Appliances : June 12, 1985–September 29, 1985. St. Paul: Goldstein Gallery, U Minnesota, 1985. Meikel, Jeffrey L. “Domesticating Modernity: Ambivalence and Appropriation, 1920–1940.” Designing Modernity; the Arts of Reform and Persuasion. Ed. Wendy Kaplan. Thames & Hudson, 1995. 143–68. O’Brien, Marion, and Aletha C. Huston. “Development of Sex-Typed Play Behavior in Toddlers.” Developmental Psychology, 21.5 (1985): 866–71. Olivarez, Jennifer Komar, Jukka Savolainen, and Juulia Kauste. Finland: Designed Environments. Minneapolis Institute of Arts and Nordic Heritage Museum, 2014. Oswell, David. The Agency of Children: From Family to Global Human Rights. Cambridge UP, 2013. Prown, Jules David. “Mind in Matter: An Introduction to Material Culture Theory and Method.” Winterthur Portfolio 17.1 (1982): 1–19. Punchard, Lorraine May. Child’s Play: Play Dishes, Kitchen Items, Furniture, Accessories. Punchard, 1982. Ranalli, Kristina. An Act Apart: Tea-Drinking, Play and Ritual. Master's thesis. U Delaware, 2013. Sears Corporate Archives. “What Is a Sears Modern Home?” n.d. <http://www.searsarchives.com/homes/index.htm>. "Target Announces New Design Partnership with Marimekko: It’s Finnish, Target Style." Target, 2 Mar. 2016. <http://corporate.target.com/article/2016/03/marimekko-for-target>. Teglasi, Hedwig. “Children’s Choices of and Value Judgments about Sex-Typed Toys and Occupations.” Journal of Vocational Behavior 18.2 (1981): 184–95. Thompson, Jane, and Alexandra Lange. Design Research: The Store That Brought Modern Living to American Homes. Chronicle, 2010.

Historians of Modern Architecture have cultivated the image of the architect as a temperamental genius, unconcerned by issues of politeness or pragmatics—a reading reinforced in cultural representations of Modern Architects, such as Howard Roark, the protagonist in Ayn Rand’s 1943 novel The Fountainhead (a character widely believed to be based on the architect Frank Lloyd Wright). The perception of the Modern Architect as an artistic hero or genius has also influenced the reception of their work. Despite their indisputable place within the architectural canon, many important works of Modern Architecture were contested on pragmatic grounds, such as cost, brief and particularly concerning issues of suitability and effectiveness in relation to climate and weather. A number of famed cases resulted in legal action between clients and architects, and in many more examples historians have critically framed these accounts to highlight alternate issues and agendas. “Complaints about the weather,” in relation to architecture, inevitably raise issues regarding a work’s “success,” particularly in view of the tensions between artistry and functionality inherent in the discipline of architecture. While in more recent decades these ideas have been framed around ideas of sustainability—particularly in relation to contemporary buildings—more traditionally they have been engaged through discussions of an architect’s ethical responsibility to deliver a habitable building that meets the client’s needs. This paper suggests these complaints often raise a broader range of issues and are used to highlight tensions inherent in the discipline. In the history of Modern Architecture, these complaints are often framed through gender studies, ethics and, more recently, artistic asceticism. Accounts of complaints and disputes are often invoked in the social construction (or deconstruction) of artistic genius – whether in a positive or negative light. Through its discussion of a number of famed examples, this paper will discuss the framing of climate in relation to the figure of the Modern Architect and the reception of the architectural “masterpiece.” Dear Monsieur Le Corbusier … In June 1930 Mme Savoye, the patron of the famed Villa Savoye on the outskirts of Paris, wrote to her architect, Le Corbusier, stating: “it is still raining in our garage” (Sbriglio 144)—a persistent theme in their correspondence. This letter followed another sent in March after discovering leaks in the garage and several bedrooms following a visit during inclement weather. While sent prior to the building’s completion, she also noted that rainfall on the bathroom skylight “makes a terrible noise […] which prevents us from sleeping in bad weather” (Sbriglio 142). Claiming to have warned Le Corbusier about the concern, the contractor refused to accept responsibility, prompting some rather fiery correspondence between the two. This problem, compounded by issues with the heating system, resulted in the house feeling, as Sbriglio notes, “cold and damp” and subject to “substantial heat loss due to the large glazing”—a cause for particular concern given the health problems of the clients’ only child, Roger Savoye, that saw him spend time in a French Sanatorium (Sbriglio 145). While the cause of Roger’s illness is not clear, at least one writer (albeit with a noticeable lack of footnotes or supporting evidence) has linked this directly to the villa (de Botton 65). Mme Savoye’s complaints about dampness, humidity, condensation and leaking in her home persisted in subsequent years, prompting Benton to summarise in 1987, “every autumn […] there were cries of distress from the Savoye family with the first rains” (Villas 204). These also extended to discussion of the heating system, which while proving insufficient was also causing flooding (Benton, "Villa" 93). In 1935 Savoye again wrote to Le Corbusier, wearily stating: It is raining in the hall, it’s raining on the ramp and the wall of the garage is absolutely soaked [….] it’s still raining in my bathroom, which floods in bad weather, as the water comes in through the skylight. The gardener’s walls are also wet through. (Sbriglio 146-7) Savoye’s understandable vexation with waterproofing problems in her home continued to escalate. With a mixture of gratitude and frustration, a letter sent two years later stated: “After innumerable demands you have finally accepted that this house which you built in 1929 in uninhabitable…. Please render it inhabitable immediately. I sincerely hope that I will not have to take recourse to legal action” (Sbriglio 147). Paradoxically, Le Corbusier was interested in the potential of architecture and urban planning to facilitate health and well-being, as well as the effects that climate may play in this. Early twentieth century medical thought advocated heliotherary (therapeutic exposure to sunlight) for a diverse range of medical conditions, ranging from rickets to tuberculosis. Similarly the health benefits of climate, such as the dryness of mountain air, had been recognised for much longer, and had led to burgeoning industries associated with health, travel and climate. The dangers of damp environments had also long been medically recognised. Le Corbusier’s awareness of the health benefits of sunshine led to the inclusion of a solarium in the villa that afforded both framed and unframed views of the surrounding countryside, such as those that were advocated in the seventeenth century as an antidote to melancholy (Burton 65-66). Both Benton and Sbriglio present Mme Savoye’s complaints as part of their comprehensive histories of an important and influential work of Modern Architecture. Each reproduce excerpts from archival letters that are not widely translated or accessible, and Benton’s 1984 essay is the source other authors generally cite in discussing these matters. In contrast, for example, Murphy’s 2002 account of the villa’s conversion from “house” to “historical monument” cites the same letters (via Benton) as part of a broader argument that highlights the “undomestic” or “unhomely” nature of the work by cataloguing such accounts of the client’s experience of discomfort while residing in the space – thus revisiting a number of common criticisms of Modern Architecture. Le Corbusier’s reputation for designing buildings that responded poorly to climate is often referenced in popular accounts of his work. For example, a 1935 article published in Time states: Though the great expanses of glass that he favors may occasionally turn his rooms into hothouses, his flat roofs may leak and his plans may be wasteful of space, it was Architect Le Corbusier who in 1923 put the entire philosophy of modern architecture into a single sentence: “A house is a machine to live in.” Reference to these issues are usually made rather minimally in academic accounts of his work, and few would agree with this article’s assertion that Le Corbusier’s influence as a phrasemaker would rival the impact of his architecture. In contrast, such issues, in relation to other architects, are often invoked more rhetorically as part of a variety of historical agendas, particularly in constructing feminist histories of architecture. While Corbusier and his work have often been the source of intellectual contention from feminist scholars—for example in regard to authorial disputes and fractious relationships with the likes of Eileen Gray or Charlotte Perriand – discussion of the functional failures in the Villa Savoye are rarely addressed from this perspective. Rather, feminist scholars have focussed their attention on a number of other projects, most notably the case of the Farnsworth House, another canonical work of Modernism. Dear Herr Mies van der Rohe … Mies van der Rohe’s Farnsworth House, completed in 1951 in Plano Illinois, was commissioned as a country weekend residence by an unmarried female doctor, a brief credited with freeing the architect from many of the usual pragmatic requirements of a permanent city residence. In response Mies designed a rectilinear steel and glass pavilion, which hovered (to avoid the flood levels) above the landscape, sheltered by maple trees, in close proximity to the Fox River. The refined architectural detail, elegant formal properties, and poetic relationship with the surrounding landscape – whether in its autumnal splendour or covered in a thick blanket of snow – captivated architects seeing it become, like the Villa Savoye, one of the most revered architectural works of the twentieth century. Prior to construction a model was exhibited in the Museum of Modern Art in New York and, upon completion the building became a pilgrimage site for architects and admirers. The exhibition of the design later fuelled debate about whether Dr Farnsworth constituted a patron or a client (Friedman 134); a distinction generating very different expectations for the responsibilities of the architect, particularly regarding the production of a habitable home that met the client’s brief versus producing a design of architectural merit. The house was intended as a frame for viewing and contemplating nature, thus seeing nature and climate aligned with the transcendental qualities of the design. Following a visit during construction, Farnsworth described the building’s relationship to the elements, writing: “the two horizontal planes of the unfinished building, floating over the meadows, were unearthly beautiful under a sun which glowed like a wild rose” (5). Similarly, in 1951, Arthur Drexler described the building as “a quantity of air caught between a floor and a roof” (Vandenberg 6). Seven years later the architect himself asserted that nature “gained a more profound significance” when viewed from within the house (Friedman 139). While the transparency of the house was “forgiven” by its isolated location and the lack of visibility from neighbouring properties, the issues a glass and steel box might pose for the thermal comfort of its occupant are not difficult to imagine. Following the house’s completion, Farnsworth fitted windows with insect screens and blinds (although Mies intended for curtains to be installed) that clumsily undermined the refined and minimalistic architectural details. Controversy surrounding the house was, in part, the result of its bold new architectural language. However, it was also due to the architect-client relationship, which turned acrimonious in a very public manner. A dispute between Mies and Farnsworth regarding unpaid fees was fought both in the courtroom and the media, becoming a forum for broader debate as various journals (for example, House Beautiful), publicly took sides. The professional female client versus the male architect and the framing of their dispute by historians and the media has seen this project become a seminal case-study in feminist architectural histories, such as Friedman’s Women and the Making of the Modern House of 1998. Beyond the conflict and speculation about the individuals involved, at the core of these discussions were the inadequacies of the project in relation to comfort and climate. For example, Farnsworth describes in her journal finding the house awash with several inches of water, leading to a court session being convened on the rooftop in order to properly ascertain the defects (14). Written retrospectively, after their relationship soured, Farnsworth’s journal delights in recounting any errors or misjudgements made by Mies during construction. For example, she described testing the fireplace to find “the house was sealed so hermetically that the attempt of a flame to go up the chimney caused an interior negative pressure” (2). Further, her growing disenchantment was reflected in bleak descriptions aligning the building with the weather. Describing her first night camping in her home, she wrote: “the expanses of the glass walls and the sills were covered with ice. The silent meadows outside white with old and hardened snow reflected the bleak [light] bulb within, as if the glass house itself were an unshaded bulb of uncalculated watts lighting the winter plains” (9). In an April 1953 article in House Beautiful, Elizabeth Gordon publicly sided with Farnsworth as part of a broader campaign against the International Style. She condemned the home, and its ‘type’ as “unlivable”, writing: “You burn up in the summer and freeze in the winter, because nothing must interfere with the ‘pure’ form of their rectangles” (250). Gordon included the lack of “overhanging roofs to shade you from the sun” among a catalogue of “human qualities” she believed architects sacrificed for the expression of composition—a list that also included possessions, children, pets and adequate kitchen facilities (250). In 1998 excerpts from this article were reproduced by Friedman, in her seminal work of feminist architectural history, and were central in her discussion of the way that debates surrounding this house were framed through notions of gender. Responding to this conflict, and its media coverage, in 1960 Peter Blake wrote: All great houses by great architects tend to be somewhat impractical; many of Corbu’s and Wright’s house clients find that they are living in too expensive and too inefficient buildings. Yet many of these clients would never exchange their houses for the most workable piece of mediocrity. (88) Far from complaining about the weather, the writings of its second owner, Peter Palumbo, poetically meditate the building’s relationship to the seasons and the elements. In his foreword to a 2003 monograph, he wrote: life inside the house is very much a balance with nature, and an extension of nature. A change in the season or an alteration of the landscape creates a marked change in the mood inside the house. With an electric storm of Wagnerian proportions illuminating the night sky and shaking the foundations of the house to their very core, it is possible to remain quite dry! When, with the melting snows of spring, the Fox River becomes a roaring torrent that bursts its banks, the house assumes a character of a house-boat, the water level sometimes rising perilously close to the front door. On such occasions, the approach to the house is by canoe, which is tied to the steps of the upper terrace. (Vandenberg 5) Palumbo purchased the house from Farnsworth and commissioned Mies’s grandson to restore it to its original condition, removing the blinds and insect screens, and installing an air-conditioning system. The critical positioning of Palumbo has been quite different from that of Farnsworth. His restoration and writings on the project have in some ways seen him positioned as the “real” architectural patron. Furthermore, his willingness to tolerate some discomfort in his inhabitation has seen him in some ways prefigure the type of resident that will be next be discussed in reference to recent owners of Wright properties. Dear Mr Wright … Accounts of weatherproofing problems in buildings designed by Frank Lloyd Wright have become the basis of mythology in the architectural discipline. For example, in 1936 Herbert Johnson and J. Vernon Steinle visited Wright’s Richard Lloyd Jones house in Oklahoma. As Jonathan Lipman wrote, “Steinle’s most prominent recollection of the house was that there were scores of tubs and canning jars in the house catching water leaking through the roof” (45). While Lipman notes the irony that both the house and office Wright designed for Johnson would suffer the same problem, it is the anecdotal accounts of the former that have perhaps attracted the most interest. An oft-recounted story tells of Johnson telephoning Wright, during a dinner party, with regard to water dripping from the ceiling into his guest-of-honour’s soup; the complaint was reportedly rebuffed unsympathetically by Wright who suggested the lady should move her chair (Farr 272). Wright himself addressed his reputation for designing buildings that leaked in his Autobiography. In reference to La Miniatura in Pasadena, of 1923, he contextualised difficulties with the local climate, which he suggested was prone to causing leaks, writing: “The sun bakes the roof for eleven months, two weeks and five days, shrinking it to a shrivel. Then giving the roof no warning whatever to get back to normal if it could, the clouds burst. Unsuspecting roof surfaces are deluged by a three inch downpour.” He continued, stating: I knew all this. And I know there are more leaking roofs in Southern California than in all the rest of the world put together. I knew that the citizens come to look upon water thus in a singularly ungrateful mood. I knew that water is all that enables them to have their being there, but let any of it through on them from above, unexpectedly, in their houses and they go mad. It is a kind of phobia. I knew all this and I have taken seriously precautions in the details of this little house to avoid such scenes as a result of negligible roofs. This is the truth. (250) Wright was quick to attribute blame—directed squarely at the builder. Never one for quiet diplomacy, he complained that the “builder had lied to [him] about the flashing under and within the coping walls” (250) and he was ignorant of the incident because the client had not informed him of the leak. He suggested the client’s silence was undoubtedly due to her “not wishing to hurt [his] feelings”. Although given earlier statements it might be speculated that she did not wish to be accused of pandering to a phobia of leaks. Wright was dismissive of the client’s inconvenience, suggesting she would be able to continue as normal until the next rains the following year and claiming he “fixed the house” once he “found out about it” (250). Implicit in this justification was the idea that it was not unreasonable to expect the client to bear a few days of “discomfort” each year in tolerance of the local climate. In true Wright style, discussions of these problems in his autobiography were self-constructive concessions. While Wright refused to take responsibility for climate-related issues in La Minatura, he was more forthcoming in appreciating the triumphs of his Imperial Hotel in Japan—one of the only buildings in the vicinity to survive the 1923 earthquake. In a chapter of his autobiography titled “Building against Doomsday (Why the Great Earthquake did not destroy the Imperial Hotel),” Wright reproduced a telegram sent by Okura Impeho stating: “Hotel stands undamaged as monument of your genius hundreds of homeless provided perfectly maintained service. Congratulations” (222). Far from unconcerned by nature or climate, Wright’s works celebrated and often went to great effort to accommodate the poetic qualities of these. In reference to his own home, Taliesin, Wright wrote: I wanted a home where icicles by invitation might beautify the eaves. So there were no gutters. And when the snow piled deep on the roofs […] icicles came to hang staccato from the eaves. Prismatic crystal pendants sometimes six feet long, glittered between the landscape and the eyes inside. Taliesin in winter was a frosted palace roofed and walled with snow, hung with iridescent fringes. (173) This description was, in part, included as a demonstration of his “superior” understanding and appreciation of nature and its poetic possibilities; an understanding not always mirrored by his clients. Discussing the Lloyd Lewis House in Libertyville, Illinois of 1939, Wright described his endeavours to keep the house comfortable (and avoid flooding) in Spring, Autumn and Summer months which, he conceded, left the house more vulnerable to winter conditions. Utilising an underfloor heating system, which he argued created a more healthful natural climate rather than an “artificial condition,” he conceded this may feel inadequate upon first entering the space (495). Following the client’s complaints that this system and the fireplace were insufficient, particularly in comparison with the temperature levels he was accustomed to in his workplace (at The Daily News), Wright playfully wrote: I thought of various ways of keeping the writer warm, I thought of wiring him to an electric pad inside his vest, allowing lots of lead wire so he could get around. But he waved the idea aside with contempt. […] Then I suggested we appeal to Secretary Knox to turn down the heat at the daily news […] so he could become acclimated. (497) Due to the client’s disinclination to bear this discomfort or use any such alternate schemes, Wright reluctantly refit the house with double-glazing (at the clients expense). In such cases, discussion of leaks or thermal discomfort were not always negative, but were cited rhetorically implying that perfunctory building techniques were not yet advanced enough to meet the architect’s expectations, or that their creative abilities were suppressed by conservative or difficult clients. Thus discussions of building failures have often been invoked in the social construction of the “architect-genius.” Interestingly accounts of the permeability of Wright’s buildings are more often included in biographical rather that architectural writings. In recent years, these accounts of weatherproofing problems have transformed from accusing letters or statements implying failure to a “badge of honour” among occupants who endure discomfort for the sake of art. This changing perspective is usually more pronounced in second generation owners, like Peter Palumbo (who has also owned Corbusier and Wright designed homes), who are either more aware of the potential problems in owning such a house or are more tolerant given an understanding of the historical worth of these projects. This is nowhere more evident than in a profile published in the real estate section of the New York Times. Rather than concealing these issues to preserve the resale value of the property, weatherproofing problems are presented as an endearing quirk. The new owners of Wright’s Prefab No. 1 of 1959, on Staten Island declared they initially did not have enough pots to place under the fifty separate leaks in their home, but in December 2005 proudly boasted they were ‘down to only one leak’ (Bernstein, "Living"). Similarly, in 2003 the resident of a Long Island Wright-designed property, optimistically claimed that while his children often complained their bedrooms were uncomfortably cold, this encouraged the family to spend more time in the warmer communal spaces (Bernstein, "In a House"). This client, more than simply optimistic, (perhaps unwittingly) implies an awareness of the importance of “the hearth” in Wright’s architecture. In such cases complaints about the weather are re-framed. The leaking roof is no longer representative of gender or power relationships between the client and the uncompromising artistic genius. Rather, it actually empowers the inhabitant who rises above their circumstances for the sake of art, invoking a kind of artistic asceticism. While “enlightened” clients of famed architects may be willing to suffer the effects of climate in the interiors of their homes, their neighbours are less tolerant as suggested in a more recent example. Complaints about the alteration of the micro-climate surrounding Frank Gehry’s Walt Disney Concert Hall in Los Angeles prompted the sandblasting of part of the exterior cladding to reduce glare. In 2004, USA Today reported that reflections from the stainless steel cladding were responsible for raising the temperature in neighbouring buildings by more than 9° Celsius, forcing neighbours to close their blinds and operate their air-conditioners. There were also fears that the glare might inadvertently cause traffic problems. Further, one report found that average ground temperatures adjacent to the building peaked at approximately 58° Celsius (Schiler and Valmont). Unlike the Modernist examples, this more recent project has not yet been framed in aid of a critical agenda, and has seemingly been reported simply for being “newsworthy.” Benign Conversation Discussion of the suitability of Modern Architecture in relation to climate has proven a perennial topic of conversation, invoked in the course of recurring debates and criticisms. The fascination with accounts of climate-related problems—particularly in discussing the work of the great Modernist Architects like Le Corbusier, Mies van der Rohe and Frank Lloyd Wright—is in part due to a certain Schadenfreude in debunking the esteem and authority of a canonical figure. This is particularly the case with one, such as Wright, who was characterised by significant self-confidence and an acerbic wit often applied at the expense of others. Yet these accounts have been invoked as much in the construction of the figure of the architect as a creative genius as they have been in the deconstruction of this figure—as well as the historical construction of the client and the historians involved. In view of the growing awareness of the threats and realities of climate change, complaints about the weather are destined to adopt a new significance and be invoked in support of a different range of agendas. While it may be somewhat anachronistic to interpret the designs of Frank Lloyd Wright or Mies van der Rohe in terms of current discussions about sustainability in architecture, these topics are often broached when restoring, renovating or adapting the designs of such architects for new or contemporary usage. In contrast, the climatic problems caused by Gehry’s concert hall are destined to be framed according to a different set of values—such as the relationship of his work to the time, or perhaps in relation to contemporary technology. While discussion of the weather is, in the conversational arts, credited as benign topic, this is rarely the case in architectural history. References Benton, Tim. The Villas of Le Corbusier 1920-1930. New Haven: Yale UP, 1987. ———. “Villa Savoye and the Architects’ Practice (1984).” Le Corbusier: The Garland Essays. Ed. H. Allen Brooks. New York: Garland, 1987. 83-105. Bernstein, Fred A. “In a House That Wright Built.” New York Times 21 Sept. 2003. 3 Aug. 2009 < http://www.nytimes.com/2003/09/21/nyregion/in-a-house-that-wright-built.html >. ———. “Living with Frank Lloyd Wright.” New York Times 18 Dec. 2005. 30 July 2009 < http://www.nytimes.com/2005/12/18/realestate/18habi.html >. Blake, Peter. Mies van der Rohe: Architecture and Structure. Harmondsworth: Penguin, 1963 (1960). Burton, Robert. The Anatomy of Melancholy, vol. II. Eds. Nicolas K. Kiessling, Thomas C. Faulkner and Rhonda L. Blair. Oxford: Clarendon, 1995 (1610). Campbell, Margaret. “What Tuberculosis Did for Modernism: The Influence of a Curative Environment on Modernist Design and Architecture.” Medical History 49 (2005): 463–488. “Corbusierismus”. Art. Time 4 Nov. 1935. 18 Aug. 2009 < http://www.time.com/time/magazine/article/0,9171,755279,00.html >. De Botton, Alain. The Architecture of Happiness. London: Penguin, 2006. Farnsworth, Edith. ‘Chapter 13’, Memoirs. Unpublished journals in three notebooks, Farnsworth Collection, Newberry Library, Chicago, unpaginated (17pp). 29 Jan. 2009 < http://www.farnsworthhouse.org/pdf/edith_journal.pdf >. Farr, Finis. Frank Lloyd Wright: A Biography. New York: Charles Scribner’s Sons, 1961. Friedman, Alice T. Women and the Making of the Modern House: A Social and Architectural History. New York: Harry N. Abrams, 1998. Gordon, Elizabeth. “The Threat to the Next America.” House Beautiful 95.4 (1953): 126-30, 250-51. Excerpts reproduced in Friedman. Women and the Making of the Modern House. 140-141. Hardarson, Ævar. “All Good Architecture Leaks—Witticism or Word of Wisdom?” Proceedings of the CIB Joint Symposium 13-16 June 2005, Helsinki < http://www.metamorfose.ntnu.no/Artikler/Hardarson_all_good_architecture_leaks.pdf >. Huck, Peter. “Gehry’s Hall Feels Heat.” The Age 1 March 2004. 22 Aug. 2009 < http://www.theage.com.au/articles/2004/02 /27/1077676955090.html >. Lipman, Jonathan. Frank Lloyd Wright and the Johnson Wax Buildings. Introduction by Kenneth Frampton. London: Architectural Press, 1984. Murphy, Kevin D. “The Villa Savoye and the Modernist Historic Monument.” Journal of the Society of Architectural Historians 61.1 (2002): 68-89. “New L.A. Concert Hall Raises Temperatures of Neighbours.” USA Today 24 Feb. 2004. 24 Aug. 2009 < http://www.usatoday.com/news/nation/2004-02-24-concert-hall_x.htm >. Owens, Mitchell. “A Wright House, Not a Shrine.” New York Times 25 July 1996. 30 July 2009 . Sbriglio, Jacques. Le Corbusier: La Villa Savoye, The Villa Savoye. Paris: Fondation Le Corbusier; Basel: Birkhäuser, 1999. Schiler, Marc, and Elizabeth Valmont. “Microclimatic Impact: Glare around the Walt Disney Concert Hall.” 2005. 24 Aug. 2009 < http://www.sbse.org/awards/docs/2005/1187.pdf >. Vandenberg, Maritz. Farnsworth House. Ludwig Mies van der Rohe. Foreword by Lord Peter Palumbo. London: Phaidon Press, 2003. Wright, Frank Lloyd. An Autobiography. New York: Duell, Sloan and Pearce, 1943.

As a genre, science fiction deals with possible futures, imagining places and technologies that typically do not exist in audiences’ own lives. Science fiction film takes this directive a step further by creating visual representations of these futures and possibilities, presenting audiences with imagined ideas of what new technologies or unfamiliar places might look like. Thus, although any science fiction text can describe sociocultural and technological futures, science fiction film goes a step further by providing images that viewers do not have to envision for themselves. This difference can enable science fiction films to deliver even more incisive stories and commentaries on futuristic technologies as “sociotechnical assemblages” (Gillespie 18) – that is, as machines whose possibilities stem from humans’ interactions with them as much as from the technologies themselves.Marquard Smith and Joanne Morra maintain that today’s society is already interested in a real-world version of sociotechnologies: they call this interest the “prosthetic impulse” (4). For Smith and Morra, the prosthetic impulse can denote either “ways that the body and technology come into contact with one another” (4) or else any exploration of boundaries between technoculture and “the body, its histories, and its mutability” (6). However, Smith and Morra also warn that the prosthetic impulse often creates unreasonable expectations of what technology can accomplish: a prosthetic can “assume an epic status that is out of proportion with its abilities to fulfill our ambitions for it” (Smith and Morra 2), and the drive to “enhance” human bodies’ capabilities can signify beliefs that abled bodies are the standard, desirable norm (S. Smith).Science fiction films in turn often pick up on real-world ideas such as Smith and Morra’s prosthetic impulse as new ways of visualizing possible futures. Knowledgeable fans could undoubtedly list several examples of prosthetics in favorite sci-fi movies, including those donned by Star Wars’ Luke Skywalker, Star Trek’s Borg collective, Mad Max: Fury Road’s Imperator Furiosa, and many more. However, these films can also heighten the prosthetic’s immoderately “epic status” (Smith and Morra 2) and result in “our fantasies for technological possibility [being] played out across depictions of impairment” (Hung par. 10). In science fiction film, then, the prosthetic impulse can strongly reinforce problematic assumptions about what human beings “need” to have added, augmented, or replaced in order to function according to subjective norms.Steven Spielberg’s 2001 film A.I. Artificial Intelligence, though, expands the implications of the prosthetic impulse even further by broadening the types of bodies, losses, and functions that we imagine prosthetics can address. Set in a dystopian future where human-driven climate change has decimated the environment, world governments have instituted mandatory birth control, and socioeconomic stratification has skyrocketed, A.I. Artificial Intelligence speaks directly to Vivian Carol Sobchack’s 2006 concern that “theoretical use of the prosthetic metaphor tends to transfer agency [from] human actors to human artifacts” (23), though it does so in a novel way.The film’s human characters, or “human actors” to use Sobchack’s term, expend their creativity and resources not to address the issues of environmental catastrophe, starvation, and class warfare that humans themselves have created: instead, they turn to manufacturing advanced robots, or “mechas”, that are literally “human artifacts” (Sobchack 23) created to help humanity avoid the debilitating consequences of its own destructive actions. As a result, the film’s mecha characters, seen most clearly in the “child-substitute mecha” David and the mecha prostitute Gigolo Joe, are positioned as prosthetic humans intended to fill social roles and functions that human beings themselves are incapable of fully satisfying.The Prosthetic HumanEven though it offers a new angle to this concept, A.I. Artificial Intelligence is hardly the only science fiction film concerned with some configuration of the prosthetic impulse. In fact, several other science fiction films incorporate one of three other versions, each building up to more and more complex possibilities before we reach the prosthetic human as envisioned in A.I.The first – and arguably most common – treatment of the prosthetic impulse in science fiction film is found in the partial prosthetic, where technology is depicted as replacing or repairing one visible part of the perceptible bodily whole. Common versions of the partial prosthetic include replacements for limbs or even certain organs, with examples such as Luke Skywalker’s prosthetic hand in Star Wars, the techno-organic Borg collective in Star Trek: The Next Generation, Bucky Barnes’s metal arm in Captain America: The Winter Soldier and other Marvel Cinematic Universe (MCU) films, and Furiosa’s metal arm in Mad Max: Fury Road. The partial prosthetic in science fiction film is the most analogous to real-world prosthetics, despite problematic conflations created by this comparison (S. Smith), and the partial prosthetic is also the one that Mailee Hung is describing when she maintains that in science fiction film “it is technological, or even technophilic, fantasy that is being explored rather than the spectrum of human ability” (par. 11).A second treatment of the prosthetic impulse in science fiction film is visible in the full-body prosthetic, which denotes a technology that completely encloses or envelops the human body. Anne McCaffrey offers an early example of this type with her “Ship Who Sang” series (1961–1969), where “brainships” are created when children with severe physical disabilities but above-average brains can be rescued from euthanasia by having their minds linked with spaceships. Thankfully, later science fiction narratives tend to avoid most of the eugenicist and ableist overtones plaguing McCaffrey’s work. Science fiction films also offer examples of full-body prosthetics that can be departed or disengaged from at will, and these prosthetics may be used to enhance an abled body rather than housing a disabled one. Examples of full-body prosthetics in science fiction film include the boxing robots of Real Steel (2011), the Jaegers of Pacific Rim (2013) and Pacific Rim: Uprising (2018), the genetically-engineered alien bodies operated by remote human pilots in James Cameron’s Avatar (2009), and the police robot MOOSE in Chappie (2015), among others. In these cases, the full-body prosthetic is a technological entity that must be interfaced with by a human consciousness – and sometimes the whole human body – in order to perform some function that the human body alone cannot accomplish.A third way of depicting the prosthetic impulse in science fiction film can be found in what Victor Grech calls Pinocchio Syndrome, or a “reverse prosthetic impulse” (265). Here technological, non-human characters “desire to become human” (Grech 263) and often attempt to gain humanity in the form of a human body, “its histories, and its mutability” (Smith and Morra 6) that will replace their own mechanical components. Examples of this third type include Data of Star Trek: The Next Generation (1987–1994 television, 1994–2002 films) and NDR-113/Andrew of the novelette “Bicentennial Man” (1967), the novel Positronic Man (1992), and the film Bicentennial Man (1999). Data is an android, and Andrew is a service robot, who both explore what it would mean to “be” human and actively pursue different means of achieving humanness – Data through human emotions and NDR-113/Andrew through a fully human body.All three of these science fiction versions – the partial prosthetic, the full prosthetic, and the reverse prosthetic impulse or Pinocchio Syndrome – tend to reinforce Smith and Morra’s warning that the prosthetic, both as an aid and as a technology, can “assume an epic status that is out of proportion with its abilities to fulfill our ambitions for it” (2). Put differently, just because these technologies exist within the films’ storyworlds does not mean that they can fix the characters’ or even the worlds’ problems, and the plots of many science fiction films actually stem from these assumptions.Of these three versions, Grech’s “reverse prosthetic impulse” (265) might initially seem the most applicable to A.I. Artificial Intelligence, particularly because most of the film follows David’s quest to find the Blue Fairy of the Pinocchio tale and petition her to make him “a real boy” (A.I. Artificial Intelligence). However, even Grech’s term does not fully cover what Spielberg’s film is attempting through its characters and its setting. Unlike robot characters who embody Grech’s reverse prosthetic impulse, David is not attempting to “become” human: instead, he articulates his struggle as the desire to “become real”, which prioritizes not humanness via a human body but instead David’s self-perceived ability to better fulfill a particular role within a nuclear family. Moreover, unlike the ways in which Data and NDR-113/Andrew fulfill primarily career-adjacent roles in their respective storyworlds – Data as a ship’s officer, NDR-113/Andrew initially as a caretaker and butler – A.I. Artificial Intelligence depicts a world in which mechas are both an “essential” form of labor in a decimated global economy, but can also be constructed to fill specifically social roles such as child or lover. Where robots like Data and NDR-113/Andrew enact a reverse prosthetic impulse in their yearning to “become” human (Grech 263), thus treating humanness and the human body as prosthetics to technology, David as a “child-substitute mecha” and Gigolo Joe as a “lover robot” (A.I. Artificial Intelligence) are more like prosthetic humans.In A.I. Artificial Intelligence, humans attempt to replace, enhance, or augment specific interpersonal relationships using “human artifacts” that function like Sobchack’s “human actors” – only, better than those human actors ever could be. David is continually described as a child who demonstrates unconditional love but never loses his temper, catches ill, or grows older; Gigolo Joe describes mecha prostitutes like himself as “the guiltless pleasures of the lonely human being” (A.I. Artificial Intelligence) and promises that they will never get pregnant, clingy, or tired of sex. Because David is a “toy boy” and Gigolo Joe is a “boy toy” (Sobchack 2) – both meant to enhance different types of human relationships without the inconveniences that a human actor would bring into the picture – A.I. Artificial Intelligence is also imagining sociocultural structures like the nuclear family or the heterosexual romantic relationship as the wholes, the social bodies, that the prosthetic human will supposedly repair. Here the prosthetic impulse becomes human beings’ drive to use reparative technologies to replace other human beings entirely, rather than simply parts or functions of the human body.David as Prosthetic HumanDavid’s role as a prosthetic human meant to repair or augment human relationships is made clear even before the character himself first appears onscreen. Instead, the film’s initial scene follows Professor Allen Hobby, the scientist who leads the team that later creates David, as he pitches a new mecha of “a qualitatively different order” to a skeptical audience (A.I. Artificial Intelligence). Hobby contends that his new robot will be capable of love “like a child for its parents” instead of the “sensuality simulators” already available (A.I. Artificial Intelligence), and moreover, that this kind of love “will be the key by which they [mechas] acquire a kind of sub-consciousness never before achieved. An inner world of metaphor, of intuition, of self-motivated reasoning, of dreams” (A.I. Artificial Intelligence). However, these plans are quickly challenged by a female scientist who poses a moral question: “Isn’t the real conundrum [whether] you can get a human to love them back?” (A.I. Artificial Intelligence). Hobby then cycles through three responses to his peer’s question, all of which point to the ways in which David is positioned as a prosthetic human.First, Hobby stresses that this new mecha will be “a perfect child caught in a freeze-frame: always loving, never ill, never changing” (A.I. Artificial Intelligence). His claim implies that families want or need a perfect child, and also that childhood perfection entails unwavering physical health, a permanently positive attitude, and unshakeable devotion to the parent(s) – all features that a real human child, as Sobchack’s “human actor”, cannot provide. Then too, Hobby’s claim that David is a child caught in “freeze-frame” perfection also hints that, as a form of technology, a prosthetic human supersedes many of a biological human’s limitations: just moments later, for example, the film’s audience learns that David’s adoptive family the Swintons have a young son, Martin, who has been placed in a cryogenic chamber until his terminal illness can be treated. For David, being “caught in a freeze-frame” of eternal and “perfect” childhood is beneficial to the Swintons, who will then experience his love and participation in their family unit forever – unlike Martin, who when similarly “frozen” cannot express or reciprocate familial affection at all, and so has been superseded by David.Hobby’s second response to the female scientist’s moral question is to assert that David, as a “child-substitute mecha” (A.I. Artificial Intelligence), will answer both a market need and a human one: because world governments issue a limited number of pregnancy licenses, Hobby argues, mechas like David may become many families’ only way of having children. Here, the family unit is imagined as incomplete without offspring, to the extent that there is a species-wide “human need” for children (A.I. Artificial Intelligence) even though global catastrophes such as climate change and mass starvation are unavoidable threats to real children’s future welfare. To this end, Hobby positions a “child-substitute mecha” like David as a prosthetic for the family unit, filling in for children without taking up any of the resources needed to raise an actual member of the population who will then face and inherit unfixable global issues. Moreover, toward the end of A.I. audiences also learn that David was created to look like Hobby’s own dead son, meaning that this entire line of child-substitute mechas has stemmed from Hobby’s own grief – and perhaps his need of a prosthetic to repair it.Finally, Hobby’s last response to his peer’s challenge is to ask: “In the beginning, didn’t God create Adam to love him?” (A.I. Artificial Intelligence). This rhetorical question reiterates how Hobby built David, reminding Hobby’s challenger – and by extension the film’s audience – that human actors are technology’s creators. The question’s rhetorical nature also implies that a creator’s status translates to their right to use such created technologies however they choose – regardless of the potential harm to either the prosthetic human or the "real" humans around them.Thus, although most of A.I. Artificial Intelligence does follow David’s journey to become “real”, it is important to realize that this quest actually stems from his being a prosthetic human rather than just Pinocchio Syndrome or a “reverse prosthetic impulse” (Grech 265). The very features of unconditional love, eternal innocence, and unchanging health that initially made David so attractive to the grieving Swintons are the same attributes that later lead to the family’s hostility when Martin does recover, and David is eventually abandoned in the woods – the prosthetic human child ousted for the “real” human child he was intended to replace. David’s longing to become “a real boy” so that Monica Swinton will return his love and welcome him home stems from his realization that he was always just a “technological substitution” (Hung par. 9) for Martin, and because of this, David’s desire to “become real” is better understood as him seeking to become a true part of the whole nuclear family instead of remaining a replacement or attachment to it. Rather than just “desire to become human” (Grech 263), David seeks to move from being a “human artifact” to becoming a “human actor” (Sobchack 23).Gigolo Joe as Prosthetic HumanWhile Gigolo Joe also serves as a prosthetic human in A.I. Artificial Intelligence, he does so in different ways than David. As a “child-substitute mecha”, David was created for intentionally prosthetic ends: even though he “can never be anything more than an approximate substitute” (Rosenbaum 74), he was still made specifically to repair or complete family units like the Swintons, rendering them “whole” by taking the place of an unavailable human child. As a mecha prostitute, though, Gigolo Joe was not created with prosthetic ends in mind: he was made to augment or supplement sexual experiences on a temporary basis, not to replace a long-term human partner or to make a sexual or romantic relationship whole by his presence within it. Also in obvious contrast to David, Gigolo Joe addresses sexual appetite rather than a need for filial love, provides short-term pleasure instead of a long-term connection, and is never intended to be seen by the film’s human characters as a human man instead of a male-shaped mecha. These are crucial differences between the two mechas’ purposes, functions, and target audiences, and Sobchack sums up this disparity by describing David and Gigolo Joe as two different types of “love machines” that remain “[s]uspended between an ironic Kubrickian critique of technological man and his Spielbergian redemption” (12–13).However, these differences between David and Gigolo Joe also translate into their being different kinds of prosthetic human. Where David was created to be a prosthetic human in the context of a childless family, replacing a needed member in order to make that family whole, Gigolo Joe takes the initiative to position himself as a prosthetic human, substituting the technology of his mecha body for the various physiological and/or emotional shortcomings of absent human sexual partners. Then too, where David rejects and attempts to outstrip his status as a “technological substitution” (Hung par. 9) for a human being, Gigolo Joe seems to exult in his part as substitute for human being.Audiences are shown this difference immediately. Where David is introduced through descriptions by Hobby, the scientist who created him and knows exactly what he wants David to accomplish, Gigolo Joe is introduced in person, alongside a nervous young woman who has apparently solicited him for sex. This unnamed woman admits that she has never had sex with a mecha before, and Gigolo Joe quickly discovers bruises from physical abuse by a human partner. In implied contrast to this unseen human partner, Gigolo Joe remains quiet, respectful, and gentle as he navigates the young woman’s communication of her fears and desires: he also assures her first that “once you’ve had a lover robot, you’ll never want a real man again” and then that “you are a goddess ... [and] you deserve much better in your life. You deserve me” (A.I. Artificial Intelligence). Both implicitly and explicitly, then, Gigolo Joe promises to provide his client with sexual and pseudo-romantic fulfillment: Sobchack frames this appeal as Gigolo Joe's ability to "satisfy every female sexual need and desire (including the illusion of romance) without wearing out” (5). But Gigolo Joe can only accomplish all of this because he is a perceptible, self-aware substitution for a human man – and a substitution that does not replicate the intentions and behaviors of his clients' "real" human partners.Gigolo Joe returns frequently to this idea that substitution is positive. Later, for instance, he explains to several fascinated teenage boys that mecha prostitutes “are the guiltless pleasures of the lonely human being. You’re not going to get us pregnant or have us to supper with Mommy and Daddy” (A.I. Artificial Intelligence), emphasizing that humans do not need to fulfill any social obligations toward mechas precisely because they are not “real” lovers. Gigolo Joe also pitches mecha sex workers by reminding his listeners that “We work under you, we work on you, and we work for you. Man made us better at what we do than was ever humanly possible” (A.I. Artificial Intelligence), suggesting that a substitute sexual partner will offer technological advantages over their human counterparts.Through dialogues and exchanges such as these, Gigolo Joe positions himself as a prosthetic human, acknowledging that he and his sex worker peers were not really meant to “repair” or “complete” human relationships even as he also maintains that mechas do replace human partners in important ways, even if temporarily. However, Gigolo Joe also recognizes the realities of being a prosthetic human in ways that David seems incapable of. For instance, when one of his clients is murdered by her human partner for seeking a replacement lover, Gigolo Joe realizes immediately that the man won’t even be suspected while Gigolo Joe himself automatically takes the blame. Similarly, Gigolo Joe is the one who can tell David that Monica Swinton “loves what you do for her, as my customers love what it is I do for them. But she does not love you. . . You were designed and built specific like the rest of us” (A.I. Artificial Intelligence). David rejects this warning, demonstrating that his creation as a prosthetic human has made him impervious to that same reality, but Gigolo Joe’s positioning himself as a prosthetic human has made him aware that being “designed and built specific” to meet humans’ needs does not negate the dangers that come along with a designed, perfected form of substitution.Prosthetic Humans and the End of HumanityThe ending of AI: Artificial Intelligence has baffled critics and audiences alike since its theatrical release. Are the alien-like Specialists real, or does David imagine these beings as a means of explaining away Hobby’s entire line of child-substitute mechas? Does David actually see Monica again, or is this the robotic equivalent of a comforting dream before he dies? Frances Flannery-Dailey outlines nine possible ways of understanding how the film ends before noting that its ambiguity and length often frustrate audiences, leaving them with a negative impression of the film.No matter which way we try to explain the ending of A.I. Artificial Intelligence, though, it is worth noting the presence of the Specialists, who claim that they are advanced beings that evolved from mechas following humanity’s extinction. Though Flannery-Daily correctly questions whether the Specialists actually exist or else are just dream-specters of David's “death”, their presence at the end of the film suggests at least the possibility of a distant future in which the prosthetic human has completely overtaken and supplanted the “real” humans that David so wanted to join. This potential ending, as well as David’s and Gigolo Joe’s poor treatment by "real" humans throughout the film, all demonstrate that the prosthetic humans in A.I. Artificial Intelligence suffer from more than the “epic status” that Smith and Morra assign to real-world prosthetics (2), or even the shortcomings visible in other versions of the prosthetic impulse as depicted in science fiction films. Instead, A.I. Artificial Intelligence becomes bleak when we realize that these prosthetic humans actually function very well, even when (wrongly) touted as miracle technologies (Smith and Morra 2), and that instead it is humans, their needs, and their visions that have fallen sadly short. Both David and Gigolo Joe do exactly what they were "designed and built specific” to do (A.I. Artificial Intelligence) and more, yet humanity has destroyed both them and itself by the end of the film regardless.ReferencesA.I. Artificial Intelligence. Dir. Steven Spielberg. Warner Bros. Pictures, 2001. Flannery-Dailey, Frances. "Robot Heavens and Robot Dreams: Ultimate Reality in A.I. and Other Recent Films." 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