Статті в журналах з теми "Sliding reserve"

Concrete dam safety is one of the hot issues in dam study with the increasing of dam’s scale and height. Sliding failure along foundation surface is a potential failure mode of concrete gravity dam, and this mode is relatively rare in practical engineering. Strength reduction method is used to analyze the progressive failure along foundation surface of concrete gravity dam, and the strength parameters of weak layer in the foundation surface are reduced to analyze the occurrence and development regularity of plastic zone. If the plastic zone of foundation surface is totally coalescent, the dam will slide along the foundation surface. To track this process, the failure path and the safety reserve coefficient would be determined. This result will provide certain scientific basis for anti-sliding stability analysis of concrete gravity dam.

Abstract In this paper, sliding mode control is used to develop two passive fault tolerant controllers for an AscTec Pelican UAV quadrotor. In the first approach, a regular sliding mode controller (SMC) augmented with an integrator uses the robustness property of variable structure control to tolerate partial actuator faults. The second approach is a cascaded sliding mode controller with an inner and outer SMC loops. In this configuration, faults are tolerated in the fast inner loop controlling the velocity system. Tuning the controllers to find the optimal values of the sliding mode controller gains is made using the ecological systems algorithm (ESA), a biologically inspired stochastic search algorithm based on the natural equilibrium of animal species. The controllers are tested using SIMULINK in the presence of two different types of actuator faults, partial loss of motor power affecting all the motors at once, and partial loss of motor speed. Results of the quadrotor following a continuous path demonstrated the effectiveness of the controllers, which are able to tolerate a significant number of actuator faults despite the lack of hardware redundancy in the quadrotor system. Tuning the controller using a faulty system improves further its ability to afford more severe faults. Simulation results show that passive schemes reserve their important role in fault tolerant control and are complementary to active techniques

The seismic degradation of bearing capacity for drained soils is shown to depend primarily on two factors related to earthquake acceleration: (a) the lateral inertial forces in the structure transmitted as shear at the foundation-soil interface and (b) the lateral body forces in the soil itself. Both induce shear stresses using up the reserve strength of the soil to carry the footing load. During those short periods when this reserve strength provided by the static design factor of safety is exhausted, the footing settles and moves laterally. Solutions for this seismic limit state defining the critical acceleration at which it occurs are determined for any value of shear transfer first by the "exact" method of characteristics and then by a simple Coulomb-type approximate mechanism. Expressions for seismic bearing capacity factors that are directly related to their static counterparts are nearly identical by either method. Thus a straightforward sliding block procedure based on the Coulomb mechanism with examples is presented for computing accumulating settlements due to the periodic loss of bearing capacity. Conversely, this approach leads to a modified static design procedure for shallow footings to limit seismic settlements in a prescribed earthquake intensity zone.

Landslides are serious geological disasters in loess areas. In order to study the effect of the filling caves in the edge of loess tableland on loess slope stability, the slope stability of sliding from the caves was calculated in irrigation when caves were filled with compacted soil, lime soil, lime-ash soil and non-filled. The results show when caves are filled with lime soil the slope stability is the highest. The effects of variability of the physical and mechanical property indexes of caver filler on loess slope stability were researched further. The results show that (1) the variation coefficients of unit weigh and the shear strength indexes of cave filler lime soil have small effect on the average value of safety reserve, but have big effect on the standard deviation of safety reserve, which explains that the design risks increase while the variation coefficient increasing. (2) with the increase of variation coefficients of unit weigh and the shear strength indexes of cave filler the failure probability increases. Especially when variation coefficient is bigger than 0.3, the failure probability of loess slope is very sensitive to variation coefficient. (3) the effect of correlation coefficient among unit weight and the shear strength indexes of cave filler on failure probability increases with the variation coefficient increasing. It is very important to guarantee filling project. Good quality of filling construction will decrease the variability of cave filler, heighten the stability of loess slope, and decrease the occurrence of loess disasters.

The lack of evaluation standard for safety coefficient based on finite element method (FEM) limits the wide application of FEM in roller compacted concrete dam (RCCD). In this paper, the strength reserve factor (SRF) method is adopted to simulate gradual failure and possible unstable modes of RCCD system. The entropy theory and catastrophe theory are used to obtain the ultimate bearing resistance and failure criterion of the RCCD. The most dangerous sliding plane for RCCD failure is found using the Latin hypercube sampling (LHS) and auxiliary analysis of partial least squares regression (PLSR). Finally a method for determining the evaluation standard of RCCD safety coefficient based on FEM is put forward using least squares support vector machines (LSSVM) and particle swarm optimization (PSO). The proposed method is applied to safety coefficient analysis of the Longtan RCCD in China. The calculation shows that RCCD failure is closely related to RCCD interface strength, and the Longtan RCCD is safe in the design condition. Considering RCCD failure characteristic and combining the advantages of several excellent algorithms, the proposed method determines the evaluation standard for safety coefficient of RCCD based on FEM for the first time and can be popularized to any RCCD.

Geomorphological evolution, erosion and retreat processes that affect the rocky coasts of the mid-western Adriatic Sea (Abruzzo, Central Italy) are the subject of this research. This coastal sector, one of the few examples of clastic soft rock coasts in the Mediterranean Sea, is characterized by active, inactive and paleo cliffs, as well as coastal slopes, composed of the clayey-sandy-arenaceous-conglomeratic marine sequence (Early-Middle Pleistocene) covered by continental deposits (Late Pleistocene-Holocene). This study provides geomorphological and 3D modelling stability analyses of the cliffs of Torre Mucchia, Punta Lunga, Punta Ferruccio (Ortona, CH) and Punta Aderci (Vasto, CH), which are popular tourist sites included in natural reserve areas. They are representative of two main types of active cliffs on soft clastic rocks: cliffs on sandstone and cliffs on conglomerate with notches. In order to evaluate the processes and factors that induce cliffs to retreat and their recent evolution, the research was based on a DEM analysis (LIDAR 2 × 2 m data), aerial photos and an orthoimages interpretation, detailed geological–geomorphological surveys, and a structural analysis; field and remote investigations were combined with numerical modelling with a FLAC3D calculation code. Geological and geomorphological field data provided reliable 3D models, and FLAC3D numerical analyses allowed the definition of the most critical and/or failure areas, and the evaluation of the controlling factors, evolution mechanisms of the slopes and the sliding kinematics of gravitational instability phenomena. Different retreat mechanisms have been observed all along the investigated coastal sectors, induced by gravitational processes due to coastal erosion cycles at the foot of the cliffs, and controlled by lithological features and joints systems. The geomorphological analysis combined with the 3D modelling (i) showed that the retreat process of the cliffs is connected to translational slides and rockfalls (cliffs on sandstone), combined rockfalls, and topples (cliffs on conglomerate), largely controlled by main joints; (ii) defined the most critical areas along the cliffs. These results are of great interest in the assessment of hazard connected to potential sliding on the cliffs. Their implementation within Geographical Information Systems provides a valuable contribution to the integrated management of coastal areas, strongly improving the identification and prediction of landscape changes and supporting a new geomorphological hazards assessment, in areas of high tourism, as well as natural and cultural landscape value.

The rolling bearing is a key component of the bogie of the rail train. The working environment is complex, and it is easy to cause cracks and other faults. Effective rolling bearing fault diagnosis can provide an important guarantee for the safe operation of the track while improving the resource utilization of the rolling bearing and greatly reducing the cost of operation. Aiming at the problem that the characteristics of the vibration data of the rolling bearing components of the railway train and the vibration mechanism model are difficult to establish, a method for long-term faults diagnosis of the rolling bearing of rail trains based on Exponential Smoothing Predictive Segmentation and Improved Ensemble Learning Algorithm is proposed. Firstly, the sliding time window segmentation algorithm of exponential smoothing is used to segment the rolling bearing vibration data, and then the segmentation points are used to construct the localized features of the data. Finally, an Improved AdaBoost Algorithm (IAA) is proposed to enhance the anti-noise ability. IAA, Back Propagation (BP) neural network, Support Vector Machine (SVM), and AdaBoost are used to classify the same dataset, and the evaluation indexes show that the IAA has the best classification effect. The article selects the raw data of the bearing experiment platform provided by the State Key Laboratory of Rail Traffic Control and Safety of Beijing Jiaotong University and the standard dataset of the American Case Western Reserve University for the experiment. Theoretical analysis and experimental results show the effectiveness and practicability of the proposed method.

When the mechanical transmission mechanism fails, such as gears and bearings in the gearbox, its vibration signal often appears as a periodic impact. Considering the influence of noise, however, the fault signal is often submerged in the noise, so it is necessary to propose a feasible and effective fault extraction method. MOMEDA (multipoint optimal minimum entropy deconvolution adjusted) overcomes the tedious iterative process of MED (minimum entropy deconvolution) and overcomes the resampling trouble in MCKD (maximum correlated kurtosis deconvolution). It is suitable for dealing with periodic impact signal. Besides, aiming at the poor ability of MOMEDA to capture the deconvolution result of target function in a strong noise environment, this paper proposes an improved MOMEDA gearbox fault feature extraction method. Considering that MOMEDA has poor anti-noise performance and can easily cause misdiagnosis in a strong noisy environment, this paper constructs an autoregressive mean sliding model to improve the noise immunity of MOMEDA. Firstly, the stability of the test signal is judged by the autocorrelation coefficient (ACF) and the partial correlation coefficient (PACF). Secondly, the ARMA (autoregressive moving average) model is constructed and a set of optimal model coefficients are obtained to filter the signal, which greatly improves MOMEDA’s ability to capture fault features. Thirdly, the fault feature is extracted by MOMEDA, and the fault information is extracted accurately under a strong noise environment. Finally, compared with AR-MED, ARMAMED, and other methods, the advantages of ARMAMOMEDA are verified. Moreover, the effectiveness and superiority of the proposed method are verified by simulation signals and experimental data from the Case Western Reserve University Bearing Data Center.

The use of liquid hydrogen as a fuel will be inevitable in the aviation of the future. This statement means that manufacturers will also implement liquid hydrogen for cooling all superconducting aviation equipment of an electric propulsion system. The development of fully electric aircraft is the most promising solution in this case. Scientists from the Department of electrical machines and power electronics of Moscow aviation institute have conducted calculations and theoretical researches of critical specific mass-dimensional parameters (MW/ton and MW/m3 at 21 K) of fully superconducting aviation synchronous generator of the electric propulsion system. The results are in this article. The article discusses the results 3D finite element modeling (FEM) simulation of a 5 MW fully superconducting synchronous generator with combined excitation. Superconducting armature and axial excitation windings based on second generation high temperature superconductors (HTS-2G) are located on the stator, which makes it possible to contactlessness and the absence of sliding seals. A dry gap will reduce gas-dynamic losses and increase the nominal peripheral speed of the rotor. The use of liquid hydrogen as a coolant makes it possible to significantly increase the linear load of the generator, and high current densities to reduce the cross-sectional area of the coils, which will make it possible to place them in individual cryostats in the future. Individual cryostats will allow to remove the heat release of magnetic losses from the cryogenic zone and reduce the consumption of refrigerant. For the purpose of internal redundancy of the HTS coils, the machine has a complete set of reserve winding made of ultrapure aluminum, also cooled by liquid hydrogen. If the superconducting coils get out of the stand, the generator will provide 15 % power on standby

Nitrogenization is one of most spread methods of surface hardening of critical parts of machines. To elaborate methodological base of structural evaluation of quality parameters of nitrogenized surface layers of sliding friction couple by methods of X-ray structural analysis and tribotechnical tests, structure and performance properties of nitrogenized structural steels and alloys were studied. Namely pearlitic and martensitic steels (40Х, 38Х2МЮА, ВКС-7), model iron-based alloys with a BCC lattice, steels alloyed by Cr, Mo, Al in amount of up to 4 % (at.), iron-based alloys with FCC lattice, alloyed by Ni (29 % (at.)), Cr, Al, Ti in the amount of up to 4 % (at.), as well as austenitic high-chromium steels 12Х18Н10Т, 08Х16Г15Н5МАФ, steel 16Х3НВФМБ-Ш and high manganese steel 40Г14Н8Х3Б1. The surface saturation of the samples was made by gas, ion, gas-baric nitrogenizing and by ion implantation of nitrogen. The sum of macroscopic (tribotechnical) and microscopic (structural) indicators was evaluated, which characterize the physics and mechanics of friction process at various hierarchical levels. This sum of indicators also provides information on properties of antifriction coatings, modified layers and performance ability of the friction couple under conditions of contact deformation. It was established, that increasing of the nitrogenizing temperature from 540 up to 700 °C for alloys with a ferrite matrix results in a decrease of the hardness of the surface layer and physical broadening of X-ray lines. In this case, the relative wear resistance reaches maximum at 620 °C. For alloys with an austenitic matrix, an increase of hardness, broadening of X-ray lines and relative wear resistance occurs with increasing of temperature. These parameters grow in the sequence Fe−Ni, Fe−Ni−Al, Fe−Ni−Cr, Fe−Ni−Ti. Gas-baric nitrogenizing enables to obtain higher performance characteristics of parts (wear resistance and contact strength). Based on the generalization of the results of experimental studies of nitrogenized steels and alloys with various compositions and various crystal lattices, the most significant characteristics of the structural state and properties of near-surface microvolumes were established, that affect the level of surface destruction during friction, as follows: the size of the alloying element nitrides particles, the distance between them, the micro-deformation of the crystal lattice of the solid solution, the values of the physical broadening of the X-ray lines of the solid solution, its hardness and the change in hardness during friction, the plasticity reserve. Generalized criteria for the properties of the surface layer, taking into account the characteristics of the structure and properties of the nitrogenized layer and the zone of surface contact plastic deformation elaborated. Also methodological foundations for the structural assessment of the quality parameters of the surface layers of sliding friction couples elaborated. Bench tests have confirmed the effectiveness of the application of the generalized structure parameter and properties of surface layers for the selection of materials for the friction unit. The formulated conditions are recommended for optimizing the nitrogenizing technological process from the standpoint of tribology and choice of materials for friction couple.

On the basis of fundamental regulations of the theory of metal plastic deformations there are defined additional reserves in the operation reliability increase of machinery operated under conditions of cyclic loadings and sliding friction.

Purpose The paper aims to focus on the individual contribution of water to the lubrication regimes in articular joints because understanding of these regimes is crucial not only for the treatment of diseases like osteoarthritis but also for the development of new implants to have a longer service cycle. Design/methodology/approach Cartilage specimen and the synovial fluid were both isolated from bovine knee joints that are enclosed by a synovial membrane under sterile conditions of a biosafety Level 2 (BSL2) cabinet. Subchondral bone was removed from the cartilage because it not only creates a stable base to place the specimen on the holder, but it also acts as a primary shock absorber protecting the overlaying cartilage under high-impact loads. A specimen holder specially designed for tests and was attached to the linear oscillation (SRV) test machine. The SRV test machine provides a reciprocating sliding motion between the cartilage samples that are submerged into the selected biological media. The entire system can be mounted on the BSL2 cabinet, sealed with the convoluted gaiter and transported to the SRV machine with a specifically designed handle for the entire system. The process ensures sterile conditions for tests on biological samples that are highly sensitive to the environmental conditions. Findings A remarkably low coefficient of friction value for distilled water constitutes more evidence to support the assumption of the impact of water in the friction behaviour of the cartilage-against-cartilage contact. As the fluid in articular cartilage (AC) effectively serves as a synovial fluid reserve and 70-80 per cent of its composition is distilled water, it can be stated that the tribotest system mimics the natural working conditions of an actual knee joint adequately. Research limitations/implications Time and limited availability of the animal-driven samples led to a focus on certain parameters mentioned in the approach. A planned scan of parameter matrix, such as variation of load and speed, would allow deeper knowledge on the lubrication regimes. Practical implications Study of relevant tribological contact in human joints might give ideas on new designs for artificial joints. Social implications Understanding of lubrication regimes is crucial not only for the treatment of diseases like osteoarthritis but also for the development of new implants to adapt motion of related joint. Originality/value Exclusion of water and application as the primary lubricant in the test system brings a new perspective to joint lubrication.

ABSTRACTThe oil and gas industry relies heavily on helicopters for transporting personnel and cargo to and from offshore installations and support vessels. A growing number of offshore helicopter operations are to moving helidecks, which include large vessels such as FPSOs, drill ships, and semi-submersibles, as well as smaller service vessels. Landing a helicopter on a moving helideck presents additional challenges to those faced on fixed helidecks, not only at the point of touchdown but also for the entire period the helicopter remains on the helideck.The UK Civil Aviation Authority (CAA), on behalf of the joint CAA/industry Helicopter Safety Research Management Committee has led a comprehensive programme of research over a number of years, aimed at improving the operational safety of helicopters landing on moving helidecks. The work focused on the aspect of the stability of helicopters once landed on a moving helideck, this being the main source of in-service incidents and accidents as evidenced in the Mandatory Occurrence Reports. The project culminated in the development of a new standard for Helideck Monitoring Systems (HMS), which was published by the Helideck Certification Agency in April 2018 with an implementation compliance date of 31 March 2021. Operations to moving helidecks not equipped with HMS meeting the new standard will be restricted to stable deck conditions from this date. The research underpinning the new standard is presented in two papers.This paper (Part A), presents the analytical approach that has been developed to model the Reserve of Stability (ROS) for all modes of failure of a helicopter on a moving offshore helideck.The analytical model covers all modes of on-deck failure (roll-over and sliding), for any nose wheel tricycle undercarriage helicopter. The mathematical expressions that have been derived are remarkably simple, physically intuitive, and make the relative contribution of all the destabilising factors easy to understand and assess. These analytical expressions can be used to calculate the ROS of any helicopter in real time, as well as for calculating an envelope of safe operating limits.This approach has many advantages compared to conventional ‘black box’ modelling methods. The main advantage is that it simplifies the modelling of the destabilising effect of helideck motion and allows the most salient parameters governing on-deck ROS to be defined, namely the Measure of Motion Severity, the instantaneous wind speed as the Measure of Wind Severity, and the wind direction relative to the helicopter (Relative Wind Direction).The main rotor lift generated during the time the helicopter remains on-deck (at Minimum Pitch on Ground, MPOG) has been one of the most important unknowns that this research programme has sought to address. An empirical model for estimating the lift at MPOG has been developed, based on experimental and field data. Practical methods for quantifying fuselage wind drag and the vertical position of the centre of gravity were also developed, which allow different helicopter types to be assessed without recourse to helicopter Original Equipment Manufacturer (OEM) proprietary information or models. Finally, a comparison and evaluation of the model against dedicated field trial measurements is presented, together with a discussion of the modelling strengths and weaknesses, and recommendations for further work.

It is sometimes imperative to modify the characteristics of materials surface reserved for the applications requiring the particular tribological properties in order to confer them certain specific properties such as the improvement of hardness, the corrosion resistance and the wear resistance. The use of aluminium and its alloys in mechanics is limited for their certain properties related to the surface whose principal one is very bad frictions behaviour, associated with a tendency of seizing and a strong sensitivity to the effect of wear. The deposit plasma is a technique which can cure these bad behaviours. It is particularly adapted to treat superficially parts of complex geometry and of rather significant number. Our work consists to study the wear behaviour of stainless steel coatings obtained by plasma on aluminium alloy substrates. The wear tests were carried out using a pin-on-disc apparatus under dry sliding conditions. Pin specimens were 100Cr6 stainless steel, while disc specimens were 316L stainless steel coating. A study will be undertaken on the tribological behaviour of the layers and the mechanisms of wear which control them for various experimental conditions (speeds and normal force) is defined, at four sliding speeds (44, 56.5,75.4, 94.3 m/s) and force of 20N.

In this paper, a moving-average method of smoothing noise based on complex exponential decomposition is applied to eliminate noise of a non-stationary signal and a non-linear signal produced by Bouc–Wen model, which are added to white Gaussian noise to simulate the noise in measured signal. The method uses a sliding window cutting the entire non-stationary and/or non-linear signal into small segments and considers that the small segments are stable and linear. The segments are decomposed into a series of components via complex exponential decomposition, and the high-energy components are reserved to reconstruct de-noised signal. Then, due to the overlap of the reconstructed segments, the average value at the same time point of reconstruction signal is regarded as the de-noised data. A non-stationary signal and a non-linear signal are selected to investigate the performance of the proposed method, the results show that the proposed method has better de-noising efficiency compared with the wavelet shrinkage method and the Savitzky–Golay filter method based on EMD (EMD-SG) for dealing with the signals with SNR of 10 dB, 15 dB, and 20 dB, and de-noised signal using the proposed method has the highest signal-to-noise ratio (SNR) and the least root mean square error (RMSE).

Under certain conditions of a helicopter flight, the main rotor can exert a rather strong effect on the tail rotor, changing its traction and power characteristics. The calculated and experimental characteristics of an isolated tail rotor under such operating conditions can differ significantly from those under conditions of interaction with the main rotor. The study of this phenomenon is an urgent task, since a change in the characteristics of the tail rotor and the conditions of its operation in the presence of the main rotor can cause a decrease in controllability margins and, as a consequence, the cause of an aircraft accident, for example, the so-called. "left rotation" of the helicopter. Since 1985, on helicopters from M. L. Mile, 42 aviation accidents occurred in units and subdivisions of the state and civil aviation of the USSR (and now Russia) due to helicopters falling into spontaneous left rotation. Over the past 10 years, 29 accidents (8 accidents and 21 accidents) have occurred for this reason. 29 helicopters were lost: 20 Mi-8, 5 Mi-24, 4 Mi-2. Experience shows that getting into an uncontrolled left rotation in almost 100% of cases ends with a collision of the helicopter with the ground and overturning it on the starboard side. The interaction of the main and tail rotor is most significantly manifested in the modes of horizontal flight with sliding at low speeds and hovering in crosswind conditions. This is due to the peculiarities of the formation of the main rotor vortex wake. In this article, the case of aerodynamic interference of the main rotor and several helicopter configurations in horizontal flight mode with the low speed with sliding (hovering in a crosswind) is considered. Using the methods of computational fluid dynamics, the degree of influence of the main rotor on the tail rotor was investigated in the described modes. The most severe operating modes of the tail rotor of each configuration have been determined. Based on the results of calculations, the most rational configuration of the tail rotor has been chosen, which has the greatest reserves of controllability under unfavorable operating conditions. The results obtained have been used in the design of a new perspective helicopter, modernization of the existing fleet, as well as improving the flight safety level.

Many sedimentary basins host important reserves of exploitable energy resources. Understanding of the present-day state of stresses, porosity, overpressure and geometric configuration is essential in order to minimize production costs and enhance safety in operations. The data that can be measured from the field is, however, limited and at a non-optimal resolution. Structural restoration (inverse modelling of past deformation) is often used to validate structural interpretations from seismic data. In addition, it provides the undeformed state of the basin, which is a pre-requisite to understanding fluid migration or to perform forward simulations. Here, we present a workflow that integrates geomechanical-based structural restoration and forward geomechanical modelling in a finite element framework. The geometry and the boundary kinematics derived from restoration are used to automatically create a forward geomechanical model. Iterative correction may then be performed by either modifying the assumptions of the restoration or modifying the restoration-derived boundary conditions in the forward model. The methodology is applied to two problems; firstly, a sand-box scale benchmark model consisting of sand sediments sliding on silicon leading to the formation of a graben structure; secondly, a field-scale thrust-related anticline from Niger Delta. Two strategies to provide further constraint on fault development in the restoration-derived forward simulation are also presented. It is shown that the workflow reproduces the first order structural features observed in the target geometry. Furthermore, it is demonstrated that the iterative approach provides improved understanding of the evolution and additional information of current-day stress and material state for the Niger Delta Case.

Traditional Simultaneous Localization and Mapping (SLAM) (with loop closure detection), or Visual Odometry (VO) (without loop closure detection), are based on the static environment assumption. When working in dynamic environments, they perform poorly whether using direct methods or indirect methods (feature points methods). In this paper, Dynamic-DSO which is a semantic monocular direct visual odometry based on DSO (Direct Sparse Odometry) is proposed. The proposed system is completely implemented with the direct method, which is different from the most current dynamic systems combining the indirect method with deep learning. Firstly, convolutional neural networks (CNNs) are applied to the original RGB image to generate the pixel-wise semantic information of dynamic objects. Then, based on the semantic information of the dynamic objects, dynamic candidate points are filtered out in keyframes candidate points extraction; only static candidate points are reserved in the tracking and optimization module, to achieve accurate camera pose estimation in dynamic environments. The photometric error calculated by the projection points in dynamic region of subsequent frames are removed from the whole photometric error in pyramid motion tracking model. Finally, the sliding window optimization which neglects the photometric error calculated in the dynamic region of each keyframe is applied to obtain the precise camera pose. Experiments on the public TUM dynamic dataset and the modified Euroc dataset show that the positioning accuracy and robustness of the proposed Dynamic-DSO is significantly higher than the state-of-the-art direct method in dynamic environments, and the semi-dense cloud map constructed by Dynamic-DSO is clearer and more detailed.

Introduction. Requirements for mineral based plasters are divided into two groups: technological and performance properties. Plasticity and ease of application are attributed to the technological properties. This determines the requirements for rheological characteristics and, first of all, for the thixotropy of mixtures. The technique is developed and tested on plaster compositions based on clay-gypsum binder which belongs to the category of local binders. Russia has significant reserves of this raw material, but at present it is not used industrially. The main reason is the lack of a scientifically based theory of hardening of the clay-gypsum binder and the formation of its properties without and with modifying additives. The purpose of this research is to develop the composition and technology of application of interior plaster compositions based on stabilized binder. The methodology of studying the rheological properties of dry plaster mixtures based on clay gypsum for interior work and wet rooms is presented. The study of the rheology of clay gypsum mixtures is carried out for the first time, it determines scientific novelty. Recommendations for the use of clay gypsum plaster mixtures determine the practical significance of the research. Materials and methods. Methods of evaluation of thixotropic properties of plaster mixtures based on clay-gypsum binder in laboratory environment are realized. Results. The valid intervals of the water-cement ratio are established which ranged from 0.46 to 0.50, determined by the limiting shear stress and the actual sliding from the vertical wall. Conclusions. The possibility of using a clay-gypsum binder in dry plaster mixtures for interior decorative works in the premises, in particular, confirmed by research. It allows us to assess the actual adhesion of plaster coatings to the concrete based surfaces and to brickwork.

Sunkoshi Small Hydropower Plant (SSHP) is a run-of-river type project constructed in Sunkoshi River located in Sindhupalchowk District of Bagmati zone of Central Development Region, Nepal. The plant started its commercial operation since March 2005. During the year 2014, 2015 and 2016 the plant faced series of natural disaster events; landslide at Jure village on 2 August 2014, earthquake (7.8 magnitude) on 25 April 2015, landslide dammed flood in Sunkoshi River on 11 August 2015 and Glacier Lake Outburst Flood (GLOF) in Sunkoshi River on 5 July 2016. The Jure landslide created 55 m dam across Sunkoshi River. Thus created landslide dammed lake inundated the powerhouse of SSHP for 36 days. About seven million cubic meters of water was reserved in the lake. The event damaged entire powerhouse building, Electromechanical Equipment (EM), tailrace culvert, portion of steel penstock pipe and staff quarter. The rehabilitation works after Jure landslides included strengthening of powerhouse building and tailrace culvert, winding of generators, replacement of electromechanical equipment and portion of penstock pipe and change of transmission line alignment. On 25 April 2015, most of the rehabilitation works were completed. The EM experts were conducting a wet test for power generation when the power-plant was hit by other natural disaster - earthquake of 7.8 Rector Scale. The earthquake and its aftershocks followed by landslide dammed outburst flood of 11 August 2015 damaged headworks structures - formed a cavern of 56.6 m3 below gravel trap, collapsed entire powerhouse building and damaged newly installed electromechanical equipment, created several landslides along water way alignment and damaged about 900 m of penstock alignment. Some innovations in designs were introduced such as construction of sliding type saddle supports, bio-engineering combined with civil engineering structures to stabilize landslides, retrofitting of powerhouse building, use of crackamite and rock drill and avoidance of heavy masonry wall and gable wall in powerhouse. After rehabilitation works, the power plant re-operated since 4 January 2016 - after about 18 months. However, the plant was again affected by a Glacier Lake Outburst Flood (GLOF) in Botekoshi River on 5 July 2016.

Background. Additional exploration of oil and gas reserves requires the application of information technologies for modelling all technological processes and interpreting the results of geophysical well logging. Reliable models of the object under exploration and the use of best practices in the field of information systems reduce investment risks associated with planning exploration works, at the same time as optimizing the planning and design of the entire process of field development.Aim. Optimization of the selection process of multivolume, multiparameter logging data when modelling a complex oil reservoir at the stage of additional field exploration, grouping well data by quality, completeness and uniformity of their distribution over the study area, as well as identifying inaccuracies (errors) in the field data (registration of signals in probes, errors in measurements of directional survey, borehole picks, etc.).Materials and methods. Examples of well logging interpretation for a complex reservoir are given, along with its distribution options for a constructed lithology cube (2D, 3D) based on the data obtained during drilling from one pilot borehole – a horizontal well, a sidetrack and a directional well. It was established that the data obtained when distributing the reservoir and modelling the lithology cube of a complex development target can be significantly different for wells located close to each other. The results obtained when constructing 2D and 3D models by different specialists revealed discrepancies in the interpretation and cross-well correlation of well sections.Results. Local zones with a sharp change in the structure were established, in particular, the concentration of extrema around some wells. The presence of such anomalies points to the presence of wells, for which the values of stratigraphic depth marks for wells located close to each other are quite different. A geostatistical algorithm was applied to correct the well data using the “sliding window” method, which became a solution for the most accurate determination of the depths of the object under exploration.Conclusions. The possibility of using a geostatistical algorithm for correcting well data based on multiparameter geophysical data was assessed; the current state of modelling the processes of exploration and development of oil fields with a complex geological structure was analysed.

Abstract. Tiawoun MAP, Tshisikhawe MP, Gwata ET. 2019. Geometric morphometry of pupae to identify four medically important flies (Order: Diptera) in Thailand. Biodiversitas 20: 1504-1509. Brackenridgea zanguebarica is one of the most threatened plant species in South Africa, found only in Thengwe village, Vhembe District Municipality, Limpopo Province, South Africa. Due to the high traditional use of its stem bark and root, the species is now facing the threat of extinction. It has been assessed in accordance with the IUCN Red List of South Africa as a critically endangered species. The aim of this study was to investigate the impact of current threats to the population in the Brackenridgea Nature Reserve, in order to improve its conservation measures. The study was carried out in the reserve, where 10 belt transects of 50 m long and 20 m wide were laid at regular intervals of 5 m to investigate the population of B. zanguebarica. Individuals were counted and the structural parameters, e.g. tree height and stem diameter size of each were measured, while the impact of plant harvesting was estimated using a sliding scale of 0 to 5. The structure of the populations in terms of the stem diameter size classes was dominated by juvenile plants that showed the bell shape pattern. In addition, 59.9% out of the total plants recorded presented signs of plant parts extraction, with the stem bark the main part extracted. The population status of B. zanguebarica was unstable and under severe threat due to the destructive harvesting of the mature tree parts, leading to poor regeneration of individuals. It is thus recommended that in order to improve its conservation measures.

Calcium cycling is a major determinant of cardiac function. S100A1 is the most abundant member of the calcium-binding S100 protein family in myocardial tissue. S100A1 interacts with a variety of calcium regulatory proteins such as SERCA2a, ryanodine receptors, L-type calcium channels and Na+/Ca2+ exchangers, thus enhancing calcium cycling. Aside from this major function, S100A1 has an important role in energy balance, myofilament sliding, myofilament calcium sensibility, titin-actin interaction, apoptosis and cardiac remodeling. Apart from its properties regarding cardiomyocytes, S100A1 is also important in vessel relaxation and angiogenesis. S100A1 potentiates cardiac function thus increasing the cardiomyocytes’ functional reserve; this is an important feature in heart failure. In fact, S100A1 seems to normalize cardiac function after myocardial infarction. Also, S100A1 is essential in the acute response to adrenergic stimulation. Gene therapy experiments show promising results, although further studies are still needed to reach clinical practice. In this review, we aim to describe the molecular basis and regulatory function of S100A1, exploring its interactions with a myriad of target proteins. We also explore its functional effects on systolic and diastolic function as well as its acute actions. Finally, we discuss S100A1 gene therapy and its progression so far.

The overarching goal of the present work is to contribute to the understanding of the relations between fetal heart rate (FHR) temporal dynamics and the well-being of the fetus, notably in terms of predicting the evolution of lactate, pH and cardiovascular decompensation (CVD). It makes uses of an established animal model of human labor, where 14 near-term ovine fetuses subjected to umbilical cord occlusions (UCO) were instrumented to permit regular intermittent measurements of metabolites lactate and base excess, pH, and continuous recording of electrocardiogram (ECG) and systemic arterial blood pressure (to identify CVD) during UCO. ECG-derived FHR was digitized at the sampling rate of 1,000 Hz and resampled to 4 Hz, as used in clinical routine. We focused on four FHR variability features which are tunable to temporal scales of FHR dynamics, robustly computable from FHR sampled at 4 Hz and within short-time sliding windows, hence permitting a time-dependent, or local, analysis of FHR which helps dealing with signal noise. Results show the sensitivity of the proposed features for early detection of CVD, correlation to metabolites and pH, useful for early acidosis detection and the importance of coarse time scales (2.5–8 s) which are not disturbed by the low FHR sampling rate. Further, we introduce the performance of an individualized self-referencing metric of the distance to healthy state, based on a combination of the four features. We demonstrate that this novel metric, applied to clinically available FHR temporal dynamics alone, accurately predicts the time occurrence of CVD which heralds a clinically significant degradation of the fetal health reserve to tolerate the trial of labor.

Abstract Background B-profile detected by lung ultrasound (LUS) during stress echocardiography (SE) consists in B-lines with lung sliding and mirrors extra-vascular lung water accumulation (“wet lung”), more often found with ischemic regional wall motion abnormalities (RWMA) and/or diastolic dysfunction. B-lines present at rest may also decrease during stress. Aim To assess the frequency and functional correlates of decreasing B-profile (“drying lung” pattern) during SE. Methods We prospectively performed transthoracic echocardiography (TTE) and LUS evaluation at rest and peak stress in 780 patients with B-lines at rest referred for exercise (n=387), vasodilator (n=324) or dobutamine (n=69) SE for known/suspected coronary artery disease (CAD) and/or heart failure (HF). Recruitment occurred in 17 certified labs of 8 countries with the ABCD protocol, including regional wall motion abnormalities with wall motion score index (WMSI), B-lines, left ventricular contractile reserve (LVCR based on force, systolic blood pressure/end-systolic volume) and Doppler-based coronary flow velocity reserve (CFVR, available in 473 patients). By LUS, we adopted the 4-site simplified scan, each site scored from 0=normal A-lines, to 10=coalescing B-lines. By selection, all patients had resting B-lines score ≥2. Invasive or noninvasive coronary angiography was available in 208 patients. Results Two B-lines stress patterns were identified: Group 1, increase or unchanged pattern (B-line stress score ≥ rest, n=698, 89%); Group 2, decrease-disappearance pattern (B-line stress score < rest for ≤2 points, n=82, 11%). Group 1 showed higher prevalence of inducible ischemia (Group 1 = 74/698 vs. Group 2 = 5/82, 11% vs. 6%, p<0.001), abnormal LVCR (Group 1 = 403/698 vs. Group 2 = 36/82, 58% vs. 42%, p=0.012) and impaired CFVR (Group 1 = 173/433 vs. Group 2 = 5/40, 40 vs. 12%, p<0.001): see figure. Two- or three-vessel coronary artery disease was also more frequent in fixed-worsening pattern (Group 1 = 88/191 vs. Group 2 = 3/17, 46 vs. 17%, p=0.024). Multivariate logistic regression analysis identified peak Force (Odds Ratio, OR, 1.039, 95% Confidence Intervals, CI: 1.006–1.074, P=0.022), stress-rest Δ-WMSI (OR 0.190, 95% CI 0.086–0.419, P<0.001) and normal CFVR (OR=1.754, 95% CI: 1.147–2.682, P=0.010) as significant predictors of drying lung pattern. Disappearing BLines Conclusion About one out of 10 patients with resting B-lines exhibit a decrease-disappearance pattern during stress. They show a more benign coronary anatomic, myocardial functional and coronary physiological profile compared to patients with the fixed-worsening pattern. The drying lung pattern is more often accompanied by a strong (higher peak force), non-ischemic and warm heart (with normal CFVR).

Micro Hydro Powewr Plant (MHPP) is a power plant that converts water energy into electrical in a small capacity. Developing MHPP means developing renewable energy which is environmentally save. In this researh the position of cross flow turbine is submerged in water so it is said cross flow zero head turbine. The purpose of this reserch is to analyze the performances of cross flow zero head turbne. The variation parameters include number of blade (12, 6 and 4 blades), fixed blades and sliding blades (unbolted blades). The turbine performances to be analyzed are system efficiency, turbine output power and generator speed. The results show that the best turbine performance is obtained when number of blades is 12 with fixed blade. This yields to the best system efficiency of 0.47% obtained at generator speed of 89.9 rpm and generator power output of 29.25 Watts.

Under the impact of seismic forces, the strain of conventional anchor cables tended to increase sharply in an instant, which could easily cause the anchor cables to fail due to stress overload. This study aimed to optimize the design of rock supporting methods under dynamic disaster events such as earthquakes and rock bursts. A scale model specimen with a mechanical sliding device was designed based on an anti-seismic anchor cable. The working mechanism and seismic strain response of anti-seismic anchor cables were studied using static and shaking table model tests. The results show that under a static force, the anti-seismic anchor cables undergo in sequence a first elastic deformation stage, a slipping stage, a second elastic deformation stage, a plastic strengthening stage, and a brittle failure stage. In the slipping stage, the anchor cables start frictional sliding while keeping the axial force unchanged so as to adapt to the large deformation of the rock mass. The anti-seismic anchor cables exhibit the three situations of no-slip, instantaneous slip, and gradual and accumulative slip under seismic excitation. With a large constant resistance to slippage, the anchor cables do not slip, which can easily cause the anchor cables to break due to stress overload. With a small constant resistance to slippage, the reserved slipping distance is instantly exhausted; a step-shaped jump appears in the time history curves of the strain of the anchor cables. In the engineering design, a preset constant resistance to slippage is needed to match the seismic force for the anchor cables to exhibit the mechanism of multiple accumulated slips. During each slipping process, the strain of the anchor cables first decreases and then increases, with the peak strain decreasing significantly. This mechanism effectively cushions the instantaneous impact force of the earthquake, releases rock deformation, and dissipates seismic energy.

All the moving components in an internal combustion engine require a lubricant that allows smooth sliding and/or rolling of interacting surfaces. Lubricant not only minimizes the friction and wear but also dissipates the heat generated due to friction and removes debris from the area of contact. Environmental concerns, decreasing mineral oil reserves and difficult disposal of nonbiodegradable conventional lubricants have urged the researchers to shift towards environmental-friendly lubricants. Number of tribological studies carried out in the past have proved that ionic liquid-based bio-lubricants are sustainable and biodegradable alternative to mineral oils. This paper presents a brief review of properties of ionic liquids and their ability to reduce friction and wear between the interacting surfaces. Tribological performance and compatibility of ionic liquids with various base-oils have been compared under boundary lubrication. The results reveal that phosphonium-based ionic liquids namely tetra-decyl tri-hexyl phosphonium bis(2,4,4-trimethylpentyl) phosphinate (P66614)i(C8)2PO2 and tri-hexyl tetra-decyl phosphonium bis(2-ethylhexyl) phosphate (P-DEHP) are more suitable for tribological applications. Since, ionic liquids can be tailored according to the application and millions of combinations are possible therefore, there is a need to summarize the published data in a more systematic and logical way.

The expediency of replacing natural quartz Sands, whose reserves are gradually exhausted, by rock screenings as part of fine-grained concretes is shown. In particular, the characteristics of granite and quartzite crushing screenings in comparison with quartz river sand are presented, as well as the results of studying the strength and abrasion of the fine-grained concrete obtained. To exclude the effect of the grain composition on the properties of concrete, aggregate samples were pre-fractionated, and the conditions for producing concrete (cement consumption, water-cement ratio, concrete mix mobility) were the same. It was found that quartz sand having rounded grains with a relatively smooth surface promotes the formation of dense particle packing and increases the strength of fine-grained concrete by 9-14%, but at the same time reduces the abrasion of similar standard samples by 20-30% compared to screenings crushing of granite and quartzite. The maximum abrasion resistance showed concrete containing quartzite screening. Quartzite – metamorphic (metasomatic) dense rock crushing which produces angular particles with a rough surface. The absence of dense packaging reduces the compressive strength of concrete samples containing quartzite aggregate compared to quartz sand. At abrasion of similar samples in a thin layer the resistance to sliding of filler particles one relative to another increases. Therefore, when choosing crushed rock fines instead of natural quartz Sands, it is important to consider the purpose of the designed fine-grained concrete. Keywords: crushing screenings, quartz sand, granite, quartzite, fine-grained concrete, strength, abrasion

There is a wide range of academic effort put into the questions of food. It is obvious that eating is necessary for everybody, but it is equally acknowledged that there are lots of cultural meanings in the area of food as well. However, it is rarely answered why preparing food is important to some people. My aim is to address this question in the context of unemployment, where food has social, recreational and spiritual meanings for the whole life. My analysis is based on the writings of the unemployed written during the unexpected recession in Finland in the 1990s. It occurred, perhaps surprisingly, that many participants wrote about food in their entries to the writing contest called 'The Story of the Unemployed'. It is worth mentioning that to be unemployed in Finland means that it is possible to get along because of the -- still on-going but shifting -- welfare state. Usually the study of food is based on specific problematics within different disciplines. Examples of these include the symbolic connection between food and culture à la Mary Douglas in anthropology, meanings and connotations of food in Barthesian semiotics, and taste as a distinctive feature or the connection between taste and class position in the sociology of taste. In addition, phenomena such as anorexia nervosa and vegetarianism has been explained within a social context by cultural sociologists. Personally I want to introduce a slightly different route. It goes from actual articulation of food and unemployment in the writings of the unemployed to the context of media and consumer culture. There are certainly some basic explanations why food is included in the stories. When you write a story in the form of a diary, it is easy to tell about eating or cooking. The time of eating is the glue of human relations, the moment of the day which connects partners together. It is not surprising, then, that human relations are of great importance when there is no work and workplace to offer social relations and position in social hierarchy. In spite of this I want to offer more interpretative and provocative insights. In the societies based on 'primitive technology', hunger was shared (see, for instance, Sahlins). On the contrary, hunger is privatised in modern and postmodern societies. The uneven sharing of food is a result of a hierarchy based on having or not having money. As a result, to keep hunger away means to have at least some money (or favourable friends). In this context, writing about food is a part of the conceptual battle against hunger. It is a conceptual proof of having survived thus far. For those who have a job, their work ensures an economic ability to stay far from the poverty. In addition to this, they have a privileged access to the space of 'normality' of being a good citizen. This is because the Protestant work ethic says so. In the case of the unemployed the relations are more complex. One's social position is marginalised since the beginning of one's period of unemployment but I suggest that food and things related to it take the place of work. Food becomes a space for continuity when work does not offer it. As long as you have food you do not have to be a criminal to go on. This should be understood in the context of Zygmunt Bauman's provocative statement that, according to the logic of consumer society, differences between its Others (poor, unemployed, criminals, madmen, drug addicts) are fading. To be poor is to be an enemy of the society. Society wants nothing from its others. It would be best if they just burnt their tents and left (Bauman 72-7). In this context food functions as an element in constructing self-definition of the unemployed. Food prevents them from sliding into a criminal position and keeps up the cultural boundaries between different forms of otherness. The actual point is not whether Bauman's claim is correct or not but its power to illuminate both the worries of the poor and the unemployed and the role food plays in it. Anything that produces empowerment for the unemployed is important in the situation which normally narrows one's possibilities to act. The situation of the unemployed is usually devoid of social dignity and material resources. That is why it is especially important for them to experience success, to learn something new and to measure it in some ways. Normally these kinds of acts are reserved for the area of work but the unemployed person transfers them into the area of cooking. Making good, perhaps healthy and affordable food allows one to experience feelings of success. This raises one's self-esteem and ability to act. It is perhaps no surprise that most writers emphasise the meaning of cooking in their lives only after they have been left without work. Food is connected to empowerment in two senses. It is important in itself but it has an instrumental function as well. It produces pleasure and it becomes a part of identity-building (for example when people put effort into making healthy or affordable food). It can also be an instrument in building different life projects when it offers feelings of success and leads to an ability to act on some different level. Thematically, food is a good example of the many activities that allow the unemployed to empower themselves. When all this is articulated in the context of media, the point and battleground become clear. The image of the unemployed presented in the media is unfortunately one-dimensional at least in Finland and perhaps in other countries as well. Outside the 'human interest' type of magazines, media describe them as unskilled job-seekers or as 'lazy bums'. This picture is part of the neoliberal machinery which blames individuals for their inability to get a job even though the reasons for high unemployment rates are mostly based on changes in the economic structure (such as the breakdown of the Soviet Union, which the Finnish economy previously leaned on, and the low state of technology except for a few leading enterprises). So the notions of food in the writings of the unemployed pointed at the media are an attempt to disarticulate and rearticulate the image of the unemployed. There is one hegemonic discourse on the topic of identity in consumer culture. Identity is not something you are born with. It is something that everybody constructs, it is changeable and what is more, it is something you can buy in postmodern consumer society. Buy it, be it! Buy caviar -- be high class! Pleasure follows purchase as well as identity. I am not saying that talk about changing identities is just capitalist mishmash. In fact, it is relevant for the unemployed as well. If identity was understood as petrifying, not possible to change, it would be sad to live as an unemployed, carrying the burdens of Protestant work ethic and seeing getting a job as the only way for constructing a reasonable life. That is why talk about contextually changing postmodern identities is not out of picture here. What is the other side of postmodern consumer identity discourse is that the unemployed have no resources to buy their identity. Thus, food comes again into the picture. For the unemployed, buying food does not lead to identity or to pleasure. It depends on who cooks (unemployed him/herself, partner, friend) and what the food tastes like. Food is not an equivalent to commodities that are ready to use. Raw materials should be handled with skill or with care before food can produce pleasure or empowerment. Accumulation of cultural capital is not based on buying as such, because it is a race where unemployed are definitely determined to resignation compared to economically privileged people. A commodity does not guarantee happiness. It must be made to mean something by using it in a specific way. You can consume cars, clothes and television without the requirement of any special skills. Food and especially cooking resonate with other rhythms. It requires skills. (This point is emphasised in Warde, especially pages 200-1.) As we have seen, food as a hobby is a part of the life projects of the unemployed. It is an important way to acquire feelings of success. As such, it produces empowerment on an individual level. At the same time, it extends its tentacles to struggle for articulations in the contexts of media and consumer culture. Its aim is to rearticulate the term unemployed as different from the passive media creations. Moreover, it is directed towards consumeristic identity discourse in the sense that food and especially cooking represent an area where identity and pleasure do not follow directly from buying and consuming. Thus, writing about food is a part of a wider spiritual quest -- a way of constructing meanings for life outside the world of work. On a more general level, this text shows clearly that the questions posed on the problematics of food are complex. Food is never only about material food for biological needs. Its discourses always point to some other spaces depending on the context. Furthermore, when food is articulated together with the unemployed, it should be seen as different from many other forms of building identity by consuming. References Bauman, Zygmunt. Work, Consumerism and the New Poor. Buckingham: Open UP, 1998. Warde, Alan. Consumption, Food and Taste: Culinary Antinomies and Commodity Culture. London: Sage, 1997. Sahlins, Marshall. Stone Age Economics. Chicago: Aldine, 1972. Citation reference for this article MLA style: Teemu Taira. "Material Food, Spiritual Quest: When Pleasure Does Not Follow Purchase." M/C: A Journal of Media and Culture 2.7 (1999). [your date of access] <http://www.uq.edu.au/mc/9910/pleasure.php>. Chicago style: Teemu Taira, "Material Food, Spiritual Quest: When Pleasure Does Not Follow Purchase," M/C: A Journal of Media and Culture 2, no. 7 (1999), <http://www.uq.edu.au/mc/9910/pleasure.php> ([your date of access]). APA style: Teemu Taira. (1999) Material food, spiritual quest: when pleasure does not follow purchase. M/C: A Journal of Media and Culture 2(7). <http://www.uq.edu.au/mc/9910/pleasure.php> ([your date of access]).