Journal articles: 'Spoof effects'

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Mercier, J. F., M. L. Cordero, S. Félix, A. Ourir, and A. Maurel. "Classical homogenization to analyse the dispersion relations of spoof plasmons with geometrical and compositional effects." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 471, no. 2182 (October 2015): 20150472. http://dx.doi.org/10.1098/rspa.2015.0472.

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We show that the classical homogenization is able to describe the dispersion relation of spoof plasmons in structured thick interfaces with periodic unit cell being at the subwavelength scale. This is because the interface in the real problem is replaced by a slab of an homogeneous birefringent medium, with an effective mass density tensor and an effective bulk modulus. Thus, explicit dispersion relation can be derived, corresponding to guided waves in the homogenized problem. Contrary to previous effective medium theories or retrieval methods, the homogenization gives effective parameters depending only on the properties of the material and on the geometry of the microstructure. Although resonances in the unit cell cannot be accounted for within this low-frequency homogenization, it is able to account for resonances occurring because of the thickness of the interface and thus, to capture the behaviour of the spoof plasmons. Beyond the case of simple grooves in a hard material, we inspect the influence of tilting the grooves and the influence of the material properties.

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Mosavi, M. R., Z. Nasrpooya, and M. Moazedi. "Advanced Anti-Spoofing Methods in Tracking Loop." Journal of Navigation 69, no. 4 (March 4, 2016): 883–904. http://dx.doi.org/10.1017/s0373463315001010.

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The Global Positioning System (GPS) has become widespread in many civilian applications. GPS signals are vulnerable to interference and even low-power interference can easily spoof GPS receivers. In this paper, two techniques are proposed based on correlators and adaptive filtering to diminish the effect of spoofing on GPS-based positioning. The suggested algorithms are implemented in the tracking loop of the receiver. As a first method, a high-resolution correlator is utilised to avoid big parts of the influence of interference. To improve the results, a multicorrelator technique is also employed. In the second method, an adaptive filter is used for estimating the parameters of authentic plus spoof signals. Interference elimination is performed by subtracting the estimated conflict effects from the measured correlation function. These techniques provide easy-to-implement quality assurance tools for anti-spoofing. As a primary step, in this article, the proposed algorithms have been implemented in a Software Receiver (SR) to prove the concept of idea in multipath-free environments.

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Qiu, Li Jun, and Su Ying Xu. "Exploration on the Dual Spool Design of Rotary Hydraulic Valve." Advanced Materials Research 989-994 (July 2014): 2845–48. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.2845.

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There is also a monomer leak valve body on the single spool, Leakage between the guide groove affected the layout of the form guide groove. Two end faces of the single spool work in the different fluid pressure in the chamber. When the working pressure of the hydraulic system is high, the pressure differential will cause the spool bearings subject to large axial force. It will increase the resistance torque of bearing rotation. Effects of axial force also limits the increase spool diameter. Double spool valve with two spool rotation series manner. Each spool in the same pressure in the working medium. Eliminating the axial force of the valve body due to fluid pressure differential generated, also reduces the resistance to rotation of the spool moment and the impact of guide groove arrangement by oil leak, and also the commutation frequency of the rotary valve can be improved by increasing the diameter of the spool.

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Pan, Xu Dong, Guang Lin Wang, and L. Zhang. "Simulation Study on Spool Edge’s Round Angle Effects on Spool Valve Orifice Discharge Characteristic." Applied Mechanics and Materials 10-12 (December 2007): 918–22. http://dx.doi.org/10.4028/www.scientific.net/amm.10-12.918.

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This paper deals with the effect on orifice discharge characteristic by the round angle of electro-hydraulic servo valve spool metering edge. The machining method of spool metering edge can cause micro round angle on the edge. This paper firstly provides 3D geometry model and computational grids of spool valve where the round angle’s range is 0-10μm and orifice opening is 0-40μm. Secondly calculates the flow rate of the orifice on the constant differential pressure circumstances. The numerical analysis is performed by using the commercial code ‘‘Fluent’’, and the numerical results show the complete flow field inside the valve. The analysis result is to obtain the influence of round angle on discharge characteristic, quantitatively. An experimental result is used in this paper to evaluate and validate the numerical analysis of the valve. The aim of this analysis is to provide a designation reference of the spool valves which are important parts of servo valve.

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Minias, Piotr, Radosław Włodarczyk, Adrian Surmacki, and Tomasz Iciek. "Silver spoon effects on plumage quality in a passerine bird." Royal Society Open Science 2, no. 6 (June 2015): 140459. http://dx.doi.org/10.1098/rsos.140459.

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A silver spoon effect means that individuals who develop under favourable circumstances enjoy a fitness or performance advantage later in life. While there is large empirical support for silver spoon effects acting on different life-history traits in birds, such as survival and reproduction, the evidence for the carry-over effects of rearing conditions on the quality of future plumage generations is lacking. Here, we examined whether abilities of individuals to undergo extensive post-juvenile moult may depend on the quality of juvenile plumage developed during the nestling phase in a small passerine showing large individual variation in the extent of post-juvenile moult, the greenfinch ( Carduelis chloris ). We found that high structural quality and carotenoid chroma of juvenile feathers were positively linked to the extent of post-juvenile moult in this species, thus allowing young birds to attain more adult-like plumage. Silver spoon effects mediated by the juvenile plumage quality were also found to have other fitness-related consequences, as individuals with high-quality juvenile feathers were in better condition during their first winter. As far as we are aware, the results provide the first correlative evidence for a silver spoon effect acting on general plumage quality in birds.

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Wang, He, Long Quan, Jiahai Huang, Guofang Gong, and Xu Yang. "Reduction of steady flow torques in a single-stage rotary servo valve." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 233, no. 4 (August 22, 2018): 718–27. http://dx.doi.org/10.1177/0954408918793402.

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In this paper, geometry optimization of spool is proposed to reduce the steady flow torques in a single-stage rotary servo valve. The steady flow torques under different spool structures are studied by computational fluid dynamics simulation and experimental test and the most effective spool structure is found out. Then, the effects of geometry parameters on the steady flow torques are studied and an optimized solution for reduction of the steady flow torques is suggested by considering the optimization qualities and production costs. The results show that modification of the geometry of spool can make the jet angle at the orifices much closer to 90°, with almost no effect on the flow rate. Processing annular groove in the spool land with increased number of grooves on one side of the spool land is an effective way to reduce the steady flow torques. The maximum value of steady flow torques reduces with a gradual decrease in reduction as the external diameter of annular groove and the number of grooves increase. With the optimized spool structure, the maximum value of steady flow torques can be reduced significantly.

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Harrar, Vanessa, and Charles Spence. "A weighty matter: The effect of spoon size and weight on food perception." Seeing and Perceiving 25 (2012): 199. http://dx.doi.org/10.1163/187847612x648288.

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When deciding on a product’s quality, we often pick it up to gauge its weight. If it’s heavy enough, we tend to think that it is good quality. We have recently shown that the weight of a dish can affect the taste and quality perception of the food it contains. Here, we varied the weight of spoons in order to determine whether the weight or size of the cutlery might influence taste perception. Teaspoons and tablespoons were tested, with one of each spoon-size artificially weighted with lead hidden into the handle (teaspoons: 2.35 and 5.67 g, and tablespoons: 3.73 and 10.84 g). Participants tasted yoghurt from each spoon and rated the yoghurt’s perceived density, price, sweetness, and pleasantness. Four within-participant ANOVAs were used to test the effects of spoon size and spoon weight on each attribute. The perceived density of the yoghurt was affected by the spoon’s weight, with yoghurt from light spoons being perceived as thicker than yoghurt sampled from a heavy spoon. The perceived price of the yoghurt also varied with spoon weight such that lighter spoons made the yoghurt taste more expensive. The most reliable effect was an interaction between spoon weight and spoon size on sweetness perception: heavy teaspoons and light tablespoons made the yoghurt appear sweeter. These data support the growing body of research demonstrating that tableware (and silverware) can affect the consumer’s judgements without their being aware.

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Pigeon, Gabriel, Marco Festa-Bianchet, and Fanie Pelletier. "Long-term fitness consequences of early environment in a long-lived ungulate." Proceedings of the Royal Society B: Biological Sciences 284, no. 1853 (April 19, 2017): 20170222. http://dx.doi.org/10.1098/rspb.2017.0222.

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Cohort effects can be a major source of heterogeneity and play an important role in population dynamics. Silver-spoon effects, when environmental quality at birth improves future performance regardless of the adult environment, can induce strong lagged responses on population growth. Alternatively, the external predictive adaptive response (PAR) hypothesis predicts that organisms will adjust their developmental trajectory and physiology during early life in anticipation of expected adult conditions but has rarely been assessed in wild species. We used over 40 years of detailed individual monitoring of bighorn ewes ( Ovis canadensis ) to quantify long-term cohort effects on survival and reproduction. We then tested both the silver-spoon and the PAR hypotheses. Cohort effects involved a strong interaction between birth and current environments: reproduction and survival were lowest for ewes that were born and lived at high population densities. This interaction, however, does not support the PAR hypothesis because individuals with matching high-density birth and adult environments had reduced fitness. Instead, individuals born at high density had overall lower lifetime fitness suggesting a silver-spoon effect. Early-life conditions can induce long-term changes in fitness components, and their effects on cohort fitness vary according to adult environment.

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CHOWDHURY, SAYAM U., MOHAMMAD FOYSAL, M. ABDULLAH ABU DIYAN, and SAKIB AHMED. "Discovery of an important wintering site of the Critically Endangered Spoon-billed Sandpiper Calidris pygmaea in the Meghna Estuary, Bangladesh." Bird Conservation International 28, no. 2 (December 7, 2017): 251–62. http://dx.doi.org/10.1017/s0959270917000247.

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SummaryThe Critically Endangered Spoon-billed Sandpiper Calidris pygmaeus is one of the most threatened migratory shorebirds in the world, breeding in Russia and wintering in Asia. The global population is declining rapidly and is projected to be extinct within a few decades without intervention. Here, we present the results of shorebird surveys in previously unrecognised site in Bangladesh along the Meghna Estuary, identified for the first time by using species distribution models. Counts and habitat preference of Spoon-billed Sandpipers and other endangered shorebirds are described here with notes on the global importance of the newly discovered site. The sum of the peak counts for each shorebird species across the two surveys was 25,993 including a minimum of 48 Spoon-billed Sandpipers. The majority of the Spoon-billed Sandpipers were observed during low tide while foraging (66.6%) and logistic regression testing for effects on the presence of foraging Spoon-billed Sandpiper indicate that they mainly preferred to forage on shallow mud. We summarise the threats to Spoon-billed Sandpipers and other birds in the new site that is currently not recognized as a Wetland of International Importance under the Ramsar Convention, although it fulfils several Ramsar Criteria. We also propose conservation and monitoring measures for long-term protection of the Spoon-billed Sandpiper and its habitat.

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Ruan, J., R. Burton, P. Ukrainetz, and Y. M. Xu. "Two-dimensional pressure control valve." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 215, no. 9 (September 1, 2001): 1031–38. http://dx.doi.org/10.1177/095440620121500903.

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The two-dimensional pressure control valve is a piloted control valve which functions by using both linear and rotary motions of a single spool. A groove on the spool land, incorporating a sensing channel, forms the pilot stage to control the pressure of a spool chamber, while the load pressure is fed to the other spool chamber. To sustain the balance of the force across the spool, the load pressure must follow the change of pressure variation along the groove while the spool is in rotary motion. The geometric parameters of the groove and the spool-to-sleeve clearance have significant effects on both the static and dynamic characteristics of the valve. Increasing the sectional size of the groove results in a large Reynolds number and the static property of the valve thus changes from that of linearity owing to the entrance effect. The linearity of the static property is also affected by the leakage through the spool-to-sleeve clearance. The dynamic characteristics of the valve are dependent upon both the structural parameters and the tune constant of the load. The stability and dynamic response were investigated under different structural parameters and time constants of the load using both linear theory and simulation methods. Experiments were designed to obtain the static and dynamic characteristics of the valve and the leakage through the pilot. A balance should be made between the linearity of the static property and the response speed; it was found that both fairly linear static and desired dynamic characteristics could be simultaneously maintained for the two-dimensional pressure control valve.

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Quisel, John D., William F. Burkholder, and Alan D. Grossman. "In Vivo Effects of Sporulation Kinases on Mutant Spo0A Proteins in Bacillus subtilis." Journal of Bacteriology 183, no. 22 (November 15, 2001): 6573–78. http://dx.doi.org/10.1128/jb.183.22.6573-6578.2001.

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ABSTRACT The phosphorylated form of the response regulator Spo0A (Spo0A∼P) is required for the initiation of sporulation in Bacillus subtilis. Phosphate is transferred to Spo0A from at least four histidine kinases (KinA, KinB, KinC, and KinD) by a phosphotransfer pathway composed of Spo0F and Spo0B. Several mutations inspo0A allow initiation of sporulation in the absence ofspo0F and spo0B, but the mechanisms by which these mutations allow bypass of spo0F andspo0B are not fully understood. We measured the ability of KinA, KinB, and KinC to activate sporulation of fivespo0A mutants in the absence of Spo0F and Spo0B. We also determined the effect of Spo0E, a Spo0A∼P-specific phosphatase, on sporulation of strains containing the spo0A mutations. Our results indicate that several of the mutations relax the specificity of Spo0A, allowing Spo0A to obtain phosphate from a broader group of phosphodonors. In the course of these experiments, we observed medium-dependent effects on the sporulation of different mutants. This led us to identify a small molecule, acetoin, that can stimulate sporulation of some spo0A mutants.

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Vaughan, N. D., and J. B. Gamble. "The Modeling and Simulation of a Proportional Solenoid Valve." Journal of Dynamic Systems, Measurement, and Control 118, no. 1 (March 1, 1996): 120–25. http://dx.doi.org/10.1115/1.2801131.

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A nonlinear dynamic model of a high speed direct acting solenoid valve is presented. The valve consists of two subsystems; a proportional solenoid and a spool assembly. These two subsystems are modeled separately. The solenoid is modeled as a nonlinear resistor/inductor combination, with inductance parameters that change with displacement and current. Empirical curve fitting techniques are used to model the magnetic characteristics of the solenoid, enabling both current and magnetic flux to be simulated. The spool assembly is modeled as a spring/mass/damper system. The inertia and damping effects of the armature are incorporated in the spool model. The solenoid model is used to estimate the spool force in order to obtain a suitable damping coefficient value. The model accurately predicts both the dynamic and steady-state response of the valve to voltage inputs. Simulated voltage, current, and displacement results are presented, which agree well with experimental results.

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Hopwood, Paul E., Allen J. Moore, and Nick J. Royle. "Effects of resource variation during early life and adult social environment on contest outcomes in burying beetles: a context-dependent silver spoon strategy?" Proceedings of the Royal Society B: Biological Sciences 281, no. 1785 (June 22, 2014): 20133102. http://dx.doi.org/10.1098/rspb.2013.3102.

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Good early nutritional conditions may confer a lasting fitness advantage over individuals suffering poor early conditions (a ‘silver spoon’ effect). Alternatively, if early conditions predict the likely adult environment, adaptive plastic responses might maximize individual performance when developmental and adult conditions match (environmental-matching effect). Here, we test for silver spoon and environmental-matching effects by manipulating the early nutritional environment of Nicrophorus vespilloides burying beetles. We manipulated nutrition during two specific early developmental windows: the larval environment and the post-eclosion environment. We then tested contest success in relation to variation in adult social environmental quality experienced (defined according to whether contest opponents were smaller (good environment) or larger (poor environment) than the focal individual). Variation in the larval environment influenced adult body size but not contest success per se for a given adult social environment experienced (an ‘indirect’ silver spoon effect). Variation in post-eclosion environment affected contest success dependent on the quality of the adult environment experienced (a context-dependent ‘direct’ silver spoon effect). By contrast, there was no evidence for environmental-matching. The results demonstrate the importance of social environmental context in determining how variation in nutrition in early life affects success as an adult.

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Elmer, K. F., and C. R. Gentle. "A parsimonious model for the proportional control valve." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 215, no. 11 (November 1, 2001): 1357–63. http://dx.doi.org/10.1243/0954406011524739.

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A generic non-linear dynamic model of a direct-acting electrohydraulic proportional solenoid valve is presented. The valve consists of two subsystems—a spool assembly and one or two unidirectional proportional solenoids. These two subsystems are modelled separately. The solenoid is modelled as a non-linear resistor-inductor combination, with inductance parameters that change with current. An innovative modelling method has been used to represent these components. The spool assembly is modelled as a mass-spring-damper system. The inertia and the damping effects of the solenoid armature are incorporated in the spool model. The model accurately and reliably predicts both the dynamic and steady state responses of the valve to voltage inputs. Simulated results are presented, which agree well with experimental results.

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Ruan, J., R. Burton, and P. Ukrainetz. "An Investigation Into the Characteristics of a Two Dimensional “2D” Flow Control Valve." Journal of Dynamic Systems, Measurement, and Control 124, no. 1 (March 22, 2001): 214–20. http://dx.doi.org/10.1115/1.1433480.

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In hydraulic servo systems, a pilot stage is often used to reduce the influence of Bernoulli’s forces and frictional forces when trying to accurately position a spool. A unique pilot controlled valve (defined as a two dimensional or “2D” flow control valve), which utilizes both rotary and linear motions of a single spool, is presented. The rotary motion uses a spiral groove in the sleeve combined with high and low pressure holes on the spool land to control the pressure in the spool chamber, while the linear motion of the spool is actuated by a hydrostatic force. Both linear theory and numerical simulation are adopted in the investigation of the characteristics of the valve. A criterion for stability is established from a linearized model of the valve. The analysis establishes the effects that certain structural parameters have on the valve’s static and dynamic characteristics. Special experimental procedures were designed to obtain properties such as mechanical stiffness, leakage flow rate, and dynamic response under different structural parameters and system pressure. It was shown that the leakage through the spool-sleeve clearance had a favorable effect on the valve stability. Theoretical and experimental results show that it is necessary to establish a balance between the static and dynamic performance in establishing appropriate structural parameters. It is also shown that the 2D flow control valve can demonstrate a high speed of response, while maintaining the pilot flow rate at a low level.

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James, Lewis J., Tyler Maher, Jack Biddle, and David R. Broom. "Eating with a smaller spoon decreases bite size, eating rate and ad libitum food intake in healthy young males." British Journal of Nutrition 120, no. 7 (August 29, 2018): 830–37. http://dx.doi.org/10.1017/s0007114518002246.

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AbstractThere is a paucity of data examining the effect of cutlery size on the microstructure of within-meal eating behaviour or food intake. Therefore, the present studies examined how manipulation of spoon size influenced these eating behaviour measures in lean young men. In study one, subjects ate a semi-solid porridge breakfast ad libitum, until satiation. In study two, subjects ate a standardised amount of porridge, with mean bite size and mean eating rate covertly measured by observation through a one-way mirror. Both studies involved subjects completing a familiarisation visit and two experimental visits, where they ate with a teaspoon (SMALL) or dessert spoon (LARGE), in randomised order. Subjective appetite measures (hunger, fullness, desire to eat and satisfaction) were made before and after meals. In study one, subjects ate 8 % less food when they ate with the SMALL spoon (SMALL 532 (SD 189) g; LARGE 575 (SD 227) g; P=0·006). In study two, mean bite size (SMALL 10·5 (SD 1·3) g; LARGE 13·7 (SD 2·6) g; P<0·001) and eating rate (SMALL 92 (SD 25) g/min; LARGE 108 (SD 29) g/min; P<0·001) were reduced in the SMALL condition. There were no condition or interaction effects for subjective appetite measures. These results suggest that eating with a small spoon decreases ad libitum food intake, possibly via a cascade of effects on within-meal eating microstructure. A small spoon might be a practical strategy for decreasing bite size and eating rate, likely increasing oral processing, and subsequently decreasing food intake, at least in lean young men.

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Arafa, H. A., and M. Rizk. "Spool Hydraulic Stiffness and Flow Force Effects in Electrohydraulic Servo-Valves." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 201, no. 3 (May 1987): 193–99. http://dx.doi.org/10.1243/pime_proc_1987_201_106_02.

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This paper deals with an analytical and experimental assessment of the flow force effects on electrohydraulic servo-valve steady state characteristics. The system mathematical model is derived, and special consideration is given to non-linearity of the feedback wire stiffness and magnetic saturation of the armature. The ‘spool hydraulic stiffness’ is defined and expressed in terms of the servo-valve parameters and supply pressure to allow clear interpretation of the nature of flow force effects. Experimental results of spool displacement decrement due to flow force versus net displacement are in good agreement with the predicted performance in a wide range of input current up to almost full magnetic saturation. The results provide evidence, on an alternative basis, of the non-linear feedback behaviour. Correlation is also made between flow force and limits of stable operation, and an expression is derived for the maximum allowable supply pressure.

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Steinwald, Mary C., Bradley J. Swanson, and Peter M. Waser. "EFFECTS OF SPOOL-AND-LINE TRACKING ON SMALL DESERT MAMMALS." Southwestern Naturalist 51, no. 1 (January 2006): 71–78. http://dx.doi.org/10.1894/0038-4909(2006)51[71:eostos]2.0.co;2.

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McDonald, Susan S., David Levine, Jim Richards, and Lauren Aguilar. "Effectiveness of adaptive silverware on range of motion of the hand." PeerJ 4 (February 15, 2016): e1667. http://dx.doi.org/10.7717/peerj.1667.

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Background.Hand function is essential to a person’s self-efficacy and greatly affects quality of life. Adapted utensils with handles of increased diameters have historically been used to assist individuals with arthritis or other hand disabilities for feeding, and other related activities of daily living. To date, minimal research has examined the biomechanical effects of modified handles, or quantified the differences in ranges of motion (ROM) when using a standard versus a modified handle. The aim of this study was to quantify the ranges of motion (ROM) required for a healthy hand to use different adaptive spoons with electrogoniometry for the purpose of understanding the physiologic advantages that adapted spoons may provide patients with limited ROM.Methods.Hand measurements included the distal interphalangeal joint (DIP), proximal interphalangeal joint (PIP), and metacarpophalangeal joint (MCP) for each finger and the interphalangeal (IP) and MCP joint for the thumb. Participants were 34 females age 18–30 (mean age 20.38 ± 1.67) with no previous hand injuries or abnormalities. Participants grasped spoons with standard handles, and spoons with handle diameters of 3.18 cm (1.25 inch), and 4.45 cm (1.75 inch). ROM measurements were obtained with an electrogoniometer to record the angle at each joint for each of the spoon handle sizes.Results.A 3 × 3 × 4 repeated measures ANOVA (Spoon handle size by Joint by Finger) found main effects on ROM of Joint (F(2, 33) = 318.68, Partialη2= .95,p< .001), Spoon handle size (F(2, 33) = 598.73, Partialη2= .97,p< .001), and Finger (F(3, 32) = 163.83, Partialη2= .94,p< .001). As the spoon handle diameter size increased, the range of motion utilized to grasp the spoon handle decreased in all joints and all fingers (p< 0.01).Discussion.This study confirms the hypothesis that less range of motion is required to grip utensils with larger diameter handles, which in turn may reduce challenges for patients with limited ROM of the hand.

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Kralev, Jordan, Alexander Mitov, and Tsonyo Slavov. "Robust μ-Controller for Hydraulic Spool Valve, Pilot Operated with Switching Micro Valves." Energies 14, no. 16 (August 7, 2021): 4817. http://dx.doi.org/10.3390/en14164817.

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Hydraulic spool valve, pilot operated with bi-state switching micro valves is a low-cost alternative to the conventional proportional and high-response valves. However, high-frequency switching causes variations in the control flow which limits achievable spool tracking error. This paper presents the design of a robust μ-controller for the spool position reference tracking synthesized with D-K iterative procedure. Furthermore, in order to reduce wind-up effects in the closed-loop, the μ-controller is decomposed to a canonical observer and state feedback components which allows explicit introduction of the saturated control signal in the controller equations. The uncertainty model required for the μ-synthesis is inferred from the nonlinear hydraulic model by identification of a Box–Jenkins model set characterized by its parameter covariance matrix. The regulator is implemented in a 32-bit programmable logic controller (PLC) and its performance is experimentally verified on a laboratory test bench of electro-hydraulic power steering system.

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Song, Zitan, Yuqi Zou, Canshi Hu, Yuanxing Ye, Chao Wang, Baoping Qing, Jan Komdeur, and Changqing Ding. "Silver spoon effects of hatching order in an asynchronous hatching bird." Behavioral Ecology 30, no. 2 (December 29, 2018): 509–17. http://dx.doi.org/10.1093/beheco/ary191.

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James, L. J., T. Maher, J. Biddle, and D. R. Broom. "Spoon size effects energy intake at an ad-libitum porridge breakfast." Appetite 101 (June 2016): 232. http://dx.doi.org/10.1016/j.appet.2016.02.114.

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Yang, Zaoli, Xin Li, Harish Garg, and Meng Qi. "Decision Support Algorithm for Selecting an Antivirus Mask over COVID-19 Pandemic under Spherical Normal Fuzzy Environment." International Journal of Environmental Research and Public Health 17, no. 10 (May 13, 2020): 3407. http://dx.doi.org/10.3390/ijerph17103407.

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With the rapid outbreak of COVID-19, most people are facing antivirus mask shortages. Therefore, it is necessary to reasonably select antivirus masks and optimize the use of them for everyone. However, the uncertainty of the effects of COVID-19 and limits of human cognition add to the difficulty for decision makers to perfectly realize the purpose. To maximize the utility of the antivirus mask, we proposed a decision support algorithm based on the novel concept of the spherical normal fuzzy (SpNoF) set. In it, firstly, we analyzed the new score and accuracy function, improved operational rules, and their properties. Then, in line with these operations, we developed the SpNoF Bonferroni mean operator and the weighted Bonferroni mean operator, some properties of which are also examined. Furthermore, we established a multi-criteria decision-making method, based on the proposed operators, with SpNoF information. Finally, a numerical example on antivirus mask selection over the COVID-19 pandemic was given to verify the practicability of the proposed method, which the sensitive and comparative analysis was based on and was conducted to demonstrate the availability and superiority of our method.

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Ferreira, J. A., F. Gomes de Almeida, and M. R. Quintas. "Semi-empirical model for a hydraulic servo-solenoid valve." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 216, no. 3 (May 1, 2002): 237–48. http://dx.doi.org/10.1177/095965180221600303.

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High-performance proportional valves, also called servo-solenoid valves, can be used today in closed-loop applications that previously were only possible with servo-valves. The valve spool motion is controlled in a closed loop with a dedicated hardware controller that enhances the valve frequency response and minimizes some non-linear effects. Owing to their lower cost and maintenance requirements as well as increasing performance they can compete with servo-valves in a large number of applications. This paper describes a new semi-empirical modelling approach for hydraulic proportional spool valves to be used in hardware-in-the-loop simulation experiments. The developed models use either data sheet or experimental values to fit the model parameters in order to reproduce both static (pressure gain, leakage flowrate and flow gain) and dynamic (frequency response) valve characteristics. Valve behaviour is divided into two parts: the static behaviour and the dynamic behaviour. A parameter decoupled model, with a variable equation structure, and a flexible model, with a fixed equation structure, are proposed for the static part. Spool dynamics are modelled by a non-linear second-order system, with limited velocity and acceleration, the parameters being adjusted using optimization techniques.

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YUGE, Atsushi, Koki TOMIOKA, Kazuhiro TANAKA, Katsuya NAGAYAMA, and Kimishiro TOKUDA. "Dynamic Characteristics of a Spool Valve Coupled with Electromagnetic and Mechanical Effects." Proceedings of the JFPS International Symposium on Fluid Power 2005, no. 6 (2005): 340–45. http://dx.doi.org/10.5739/isfp.2005.340.

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Sanghvi, Krish, Felix Zajitschek, Maider Iglesias-Carrasco, and Megan L. Head. "Sex- and trait-specific silver-spoon effects of developmental environments, on ageing." Evolutionary Ecology 35, no. 3 (April 11, 2021): 367–85. http://dx.doi.org/10.1007/s10682-021-10115-y.

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Spakovszky, Z. S. "Analysis of Aerodynamically Induced Whirling Forces in Axial Flow Compressors." Journal of Turbomachinery 122, no. 4 (February 1, 2000): 761–68. http://dx.doi.org/10.1115/1.1312801.

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A new analytical model to predict the aerodynamic forces in axial flow compressors due to asymmetric tip-clearance is introduced. The model captures the effects of tip-clearance induced distortion (i.e., forced shaft whirl), unsteady momentum-induced tangential blade forces, and pressure-induced forces on the spool. Pressure forces are shown to lag the tip-clearance asymmetry, resulting in a tangential (i.e., whirl-inducing) force due to spool pressure. This force can be of comparable magnitude to the classical Alford force. Prediction and elucidation of the Alford force is also presented. In particular, a new parameter denoted as the blade loading indicator is deduced. This parameter depends only on stage geometry and mean flow and determines the direction of whirl tendency due to tangential blade loading forces in both compressors and turbines. All findings are suitable for incorporation into an overall dynamic system analysis and integration into existing engine design tools. [S0889-504X(00)01604-4]

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Ye, Yi, Chen-Bo Yin, Xing-Dong Li, Wei-jin Zhou, and Feng-feng Yuan. "Effects of groove shape of notch on the flow characteristics of spool valve." Energy Conversion and Management 86 (October 2014): 1091–101. http://dx.doi.org/10.1016/j.enconman.2014.06.081.

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Omer Bendori, Shira, Shaul Pollak, Dorit Hizi, and Avigdor Eldar. "The RapP-PhrP Quorum-Sensing System of Bacillus subtilis Strain NCIB3610 Affects Biofilm Formation through Multiple Targets, Due to an Atypical Signal-Insensitive Allele of RapP." Journal of Bacteriology 197, no. 3 (November 24, 2014): 592–602. http://dx.doi.org/10.1128/jb.02382-14.

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The genome ofBacillus subtilis168 encodes eightrap-phrquorum-sensing pairs. Rap proteins of all characterized Rap-Phr pairs inhibit the function of one or several important response regulators: ComA, Spo0F, or DegU. This inhibition is relieved upon binding of the peptide encoded by the cognatephrgene.Bacillus subtilisstrain NCIB3610, the biofilm-proficient ancestor of strain 168, encodes, in addition, therapP-phrPpair on the plasmid pBS32. RapP was shown to dephosphorylate Spo0F and to regulate biofilm formation, but unlike other Rap-Phr pairs, RapP does not interact with PhrP. In this work we extend the analysis of the RapP pathway by reexamining its transcriptional regulation, its effect on downstream targets, and its interaction with PhrP. At the transcriptional level, we show thatrapPandphrPregulation is similar to that of otherrap-phrpairs. We further find that RapP has an Spo0F-independent negative effect on biofilm-related genes, which is mediated by the response regulator ComA. Finally, we find that the insensitivity of RapP to PhrP is due to a substitution of a highly conserved residue in the peptide binding domain of therapPallele of strain NCIB3610. Reversing this substitution to the consensus amino acid restores the PhrP dependence of RapP activity and eliminates the effects of therapP-phrPlocus on ComA activity and biofilm formation. Taken together, our results suggest that RapP strongly represses biofilm formation through multiple targets and that PhrP does not counteract RapP due to a rare mutation inrapP.

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Pountney, D. C., W. Weston, and M. R. Banieghbal. "A Numerical Study of Turbulent Flow Characteristics of Servo-Valve Orifices." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power Engineering 203, no. 2 (May 1989): 139–47. http://dx.doi.org/10.1243/pime_proc_1989_203_018_02.

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A numerical scheme based on the k—e turbulences model has been employed to determine turbulent flow characteristics of servo-valve orifices. Numerical predictions of flow patterns, flow coefficients and pressure variations within the valve orifice are presented and their implications for control of spool forces and cavitation effects are considered. The limitations of the model are considered and a proposal for more effective servo-valve modelling, together with a comparable experimental study, is made.

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Bolhuis, D., R. Keast, and L. P. Newman. "Consumption with fork or spoon? Effects on acute food intake, eating rate and palatability." Journal of Nutrition & Intermediary Metabolism 4 (June 2016): 44. http://dx.doi.org/10.1016/j.jnim.2015.12.317.

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Calvard, Thomas Stephen, and Cindy Rajpaul-Baptiste. "The Bittersweet Silver Spoon: Considering the Mixed and Contextual Effects of Nepotistic Organizational Practices." Industrial and Organizational Psychology 8, no. 1 (March 2015): 31–37. http://dx.doi.org/10.1017/iop.2014.8.

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The focal article by Jones and Stout (2015) has revealed just how much there is for industrial and organizational (I-O) psychologists to try to unpack in the implications of nepotism for organizations and employees, particularly in relation to selection and development practices. In this brief commentary, we try to make two contributions to this state of affairs. First, we discuss the importance of disentangling different types of nepotistic and social connection preference (SCP) effects in context because these differences may in turn implicate distinct processes and effects that shape employee outcomes. We do this in part by drawing on findings from some of our own data on nepotistic hiring within a Caribbean coast guard organization (Rajpaul-Baptiste & Calvard, 2012). Second, we argue that for nepotism and SCP to be considered more fully and fruitfully as topics for I-O research and practice, these topics need to be integrated and consolidated more thoroughly along with existing work on diversity management, cross-cultural psychology, organizational discourses, organizational contexts, institutional logics, and social network approaches. We believe this is likely to produce more theoretical, methodological, empirical, and practical coherence across emerging I-O research in this area, without leading researchers and practitioners to reinvent the wheel or misguidedly rely on cultural stereotypes about nepotism and cronyism.

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Jia, Wen Hua, Chen Bo Yin, and Guo Jin Jiang. "Flow Features Analysis of Throttle Notches of Proportional Direct Valve." Advanced Materials Research 189-193 (February 2011): 2285–88. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.2285.

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Flow features, specially, flow rate, discharge coefficient and efflux angle under different operating conditions are numerically simulated, and the effects of shapes and the number of notches on them are analyzed. To simulate flow features, 3D models are developed as commercially available fluid flow models. Most construction machineries in different conditions require different actions. Thus, in order to be capable of different actions and exhibit good dynamic behavior, flow features should be achieved in designing an optimized proportional directional spool valve.

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Liu, Jin-gang, Gao-sheng Wang, Tian-heng Peng, and Sheng-qiang Jiang. "Numerical Simulation of Solid Particle Erosion in Aluminum Alloy Spool Valve." Mathematical Problems in Engineering 2019 (December 5, 2019): 1–16. http://dx.doi.org/10.1155/2019/9465406.

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Aluminum alloy spool valve body material is prone to severe wear on the wall under the condition of oil contamination. Aiming at this problem, combined with the theory of liquid-solid two-phase flow and erosion wear, the wear prediction model of aluminum alloy sliding valve wall is established based on computational fluid dynamics, and the effects of turbulence and wall materials, particle size distribution, and particle shape on particle motion are discussed. The calculation of the wear prediction model is done with Fluent software. This study predicts the wear of the wall under actual working conditions and calculates the influence of particle size, particle shape, and pressure difference on the wall wear of the aluminum alloy sliding valve. The research results have certain significance for the maintenance and upkeep of aluminum alloy sliding valve wall, improved design, and life prediction.

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Anderson, Randall T., and Perry Y. Li. "Mathematical Modeling of a Two Spool Flow Control Servovalve Using a Pressure Control Pilot1." Journal of Dynamic Systems, Measurement, and Control 124, no. 3 (July 23, 2002): 420–27. http://dx.doi.org/10.1115/1.1485287.

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A nonlinear dynamic model for an unconventional, commercially available electrohydraulic flow control servovalve is presented. The two stage valve differs from the conventional servovalve design in that: it uses a pressure control pilot stage; the boost stage uses two spools, instead of a single spool, to meter flow into and out of the valve separately; and it does not require a feedback wire and ball. Consequently, the valve is significantly less expensive. The proposed model captures the nonlinear and dynamic effects. The model has been coded in Matlab/Simulink and experimentally validated.

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Canatan, Duran, and Handan Duman. "The Antioxidant Effects of Capparis Ovata and Deferasirox in Patients with Thalassemia Major." Blood 112, no. 11 (November 16, 2008): 5427. http://dx.doi.org/10.1182/blood.v112.11.5427.5427.

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Abstract Introduction: Iron overload and auto-oxidation of unpaired globin chains is the main cause of oxidative stress in thalassemia. The high levels of MDA in iron overloaded thalassemic patients is the best sample of oxidative stres. Generally decreased iron burden was associated with decreased oxidant damage. In vitro studies were shown that iron chelators such as deferoxamine and deferipron neutrolyse intraselluler free iron and inhibits oxidation. We aimed to show the antioxidant effects of capparis ovatta and deferasirox in thalassemic patients. Material-Method: A total number of 40 thalassemia major patient aged between 7–30 years, who has been taken regular transfusion (15 cc/kg/month to maintain Hb >10 gr/dl) and chelation therapy (30 mg/kg/day ICL-670) are involved. They were separated into two groups as control and study group randomly. Both study and control group were followed by transfusion and chelation therapy. In study In addition study group have been taken capparis marmelade at the breakfast with a dose of a dessert-spoon (12.5 gr) younger than 10 years and a soup-spoon (25 gr) older than ten years for 6 months. Hematological and biochemical parameters, ferritin at every month and oxidative-antioxidant status (MDA, CAT, Gpx, SOD) were measured at the beginning and at the end of the study. Results: Serum ferritin and MDA levels declined significiantly in both groups (for ferritin; control group p= 0.00; study group p=0.00) during the study but a much more decrease occured at MDA levels in the cappari given group (p=0.02). There was no statistically significant difference between the groups at the initial and last SOD CAT, GPX, SOD levels. Further more in the study group a significant decrease in liver function tests was occured (AST p= 0.05, ALT p= 0.01). Conclusion: Our findings suggest that combination of capparis with deferasirox may be usefull for decreasing the effect of oxidative damage.

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Sugiyama, N. "System Identification of Jet Engines." Journal of Engineering for Gas Turbines and Power 122, no. 1 (October 20, 1999): 19–26. http://dx.doi.org/10.1115/1.483172.

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System identification plays an important role in advanced control systems for jet engines, in which controls are performed adaptively using data from the actual engine and the identified engine. An identification technique for jet engine using the Constant Gain Extended Kalman Filter (CGEKF) is described. The filter is constructed for a two-spool turbofan engine. The CGEKF filter developed here can recognize parameter change in engine components and estimate unmeasurable variables over whole flight conditions. These capabilities are useful for an advanced Full Authority Digital Electric Control (FADEC). Effects of measurement noise and bias, effects of operating point and unpredicted performance change are discussed. Some experimental results using the actual engine are shown to evaluate the effectiveness of CGEKF filter. [S0742-4795(00)00401-4]

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Kelleher, Shannon R., Aimee J. Silla, Petri T. Niemelä, Niels J. Dingemanse, and Phillip G. Byrne. "Dietary carotenoids affect the development of individual differences and behavioral plasticity." Behavioral Ecology 30, no. 5 (June 4, 2019): 1273–82. http://dx.doi.org/10.1093/beheco/arz074.

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AbstractNutritional conditions experienced during development are expected to play a key role in shaping an individual’s behavioral phenotype. The long term, irreversible effects of nutritional conditions on behavioral variation among and within individuals remains largely unexplored. This study aimed to investigate how long-term carotenoid availability (representing low vs. high quality nutritional conditions) during both larval and adult life stages influences the expression of among-individual variation (animal personality) and within-individual variation (behavioral plasticity). We tested for personality and plasticity along the exploration/avoidance behavioral axis in the Southern Corroboree frog (Pseudophryne corroboree). We predicted that treatment groups receiving carotenoids during early development would be more exploratory and have greater among- and within-individual variation compared with individuals that did not receive carotenoids (i.e., silver spoon hypothesis). Superior nutritional conditions experienced during development are expected to provide individuals with resources needed to develop costly behaviors, giving them an advantage later in life irrespective of prevailing conditions. Unexpectedly, frogs that did not receive carotenoids as larvae expressed greater among-individual variance in exploration behavior. Additionally, frogs that did not receive carotenoids at either life stage displayed greater within-individual variance. Our findings provide no support for the silver spoon hypothesis but suggest that inconsistent nutritional conditions between life stages may adversely affect the development of behavioral phenotypes. Overall, our results indicate that early and late life nutritional conditions affect the development of personality and plasticity. They also highlight that nutritional effects on behavior may be more complex than previously theorized.

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Hu, Xianjin, Kun Yang, and Cheng Zhang. "Optimization of Preparation Conditions for Side-Emitting Polymer Optical Fibers Using Response Surface Methodology." Polymers 12, no. 12 (December 21, 2020): 3062. http://dx.doi.org/10.3390/polym12123062.

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Polymer optical fibers (POFs) were used for preparing side-emitting polymer optical fibers (SPOFs), which were processed with acetone and n-hexane combined in selected proportions by a solvent treatment method. The effects of the volume ratio of acetone to n-hexane and treatment time on response variable factors were investigated. The center composite design (CCD) based response surface methodology (RSM), a quadratic model, and a two-factor interaction model were developed to relate the preparation variables of illumination intensity, breaking strength, and rigidity. According to analysis of variance (ANOVA), the factors affecting the optimization of each response factor were determined. The predicted values after process optimization were found to be highly similar to the experimental values. The optimal conditions for the preparation of SPOF were as follows: the volume ratio of acetone to hexane was 1.703, and the treatment time was 2.716 s. The three response variables of SPOF prepared under the optimal conditions were: illumination intensity 19.339 mV, breaking strength 5.707 N, and rigidity 572.013 N·mm2.

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Fondelli, Tommaso, Antonio Andreini, Riccardo Da Soghe, Bruno Facchini, and Lorenzo Cipolla. "Numerical Simulation of Oil Jet Lubrication for High Speed Gears." International Journal of Aerospace Engineering 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/752457.

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The Geared Turbofan technology is one of the most promising engine configurations to significantly reduce the specific fuel consumption. In this architecture, a power epicyclical gearbox is interposed between the fan and the low pressure spool. Thanks to the gearbox, fan and low pressure spool can turn at different speed, leading to higher engine bypass ratio. Therefore the gearbox efficiency becomes a key parameter for such technology. Further improvement of efficiency can be achieved developing a physical understanding of fluid dynamic losses within the transmission system. These losses are mainly related to viscous effects and they are directly connected to the lubrication method. In this work, the oil injection losses have been studied by means of CFD simulations. A numerical study of a single oil jet impinging on a single high speed gear has been carried out using the VOF method. The aim of this analysis is to evaluate the resistant torque due to the oil jet lubrication, correlating the torque data with the oil-gear interaction phases. URANS calculations have been performed using an adaptive meshing approach, as a way of significantly reducing the simulation costs. A global sensitivity analysis of adopted models has been carried out and a numerical setup has been defined.

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Richer, Edmond, and Yildirim Hurmuzlu. "A High Performance Pneumatic Force Actuator System: Part I—Nonlinear Mathematical Model." Journal of Dynamic Systems, Measurement, and Control 122, no. 3 (June 23, 1999): 416–25. http://dx.doi.org/10.1115/1.1286336.

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In this paper, we developed a detailed mathematical model of dual action pneumatic actuators controlled with proportional spool valves. Effects of nonlinear flow through the valve, air compressibility in cylinder chambers, leakage between chambers, end of stroke inactive volume, and time delay and attenuation in the pneumatic lines were carefully considered. We performed system identification, numerical simulation, and model validation experiments for two types of air cylinders and different connecting tubes length. The mathematical model of the present article is used in a sequel article to develop high performance nonlinear pneumatic force controllers. [S0022-0434(00)00503-7]

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Tsai, Chia-Wen. "How Much Can Computers and Internet Help?" International Journal of Technology and Human Interaction 7, no. 1 (January 2011): 67–81. http://dx.doi.org/10.4018/jthi.2011010105.

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Computing education in Taiwan is ineffective. Most teaching efforts in private vocational schools have been devoted to helping students pass tests through a “spoon-feeding” teaching method. Under such constraints, students may lose their long-term competence in practical terms. In this study, the author conducted a series of quasi-experiments to examine the long-term effects of web-mediated problem-based learning (PBL), self-regulated learning (SRL), and their combinations on students’ computing skills over three years. The author re-examined students’ long-term computing skills three years after the start of the related course. Results reveal that effects of web-mediated PBL, SRL, and their combinations on students’ long-term computing skills are significant. The implications for scholars and teachers engaged in online learning were also discussed.

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Redmond, John A., Diann Brei, Jonathan Luntz, Alan L. Browne, and Nancy L. Johnson. "Spool-packaging of shape memory alloy actuators: Performance model and experimental validation." Journal of Intelligent Material Systems and Structures 23, no. 2 (January 2012): 201–19. http://dx.doi.org/10.1177/1045389x11431742.

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Shape memory alloy (SMA) actuators in the wire form are attractive because of their simplistic architecture and electrical operation, and their manufacturability at high yields and low cost. While SMA actuators are known for their superior work density among smart materials, packaging long lengths of SMA wire needed for moderate to large motions is an ongoing technical challenge. This article investigates spooling as a packaging approach to provide more compact actuator footprints. An analytical, quasi-static model is derived to provide a foundational tool for the analysis and synthesis of spool-packaged SMA wire actuators. The model predicts motion with respect to a generalized architecture, and specifiable geometric, material, and loading parameters. The model prediction accounts for the effects of local friction loss and bending strains, and for a “binding” limitation due to accumulated friction. An experimental validation study demonstrates the model’s ability to predict actuator motion well in terms of form and magnitude with respect to load and packaging geometry. This model provides a basis for a systematic application of spooled-packaging techniques to overcome packaging limitations of SMA, positioning SMA wire actuators as a viable alternative in many applications.

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Awang Saifudin, Awang Raisudin, and Nurul Musfirah Mazlan. "Computational Exploration of a Two-Spool High Bypass Turbofan Engine's Component Deterioration Effects on Engine Performance." Applied Mechanics and Materials 629 (October 2014): 104–8. http://dx.doi.org/10.4028/www.scientific.net/amm.629.104.

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Aircraft engines are exposed to degradation due to several factors such as environmental air pollution, fuel content and ageing or degradation of engine’s components, which are experienced within specified time. While the turbofan in operation, its components deteriorate and consequently affect its performance. This study is aimed to computationally investigate the effect of components degradation on engine performance. A high bypass turbofan engine operated at cruise is selected for this evaluation and the simulation was performed using the Gas Turbine Simulation Program (GSP). The affected components considered are turbines and compressors with deterioration rate ranging from 0% to 5%. The effect of selected deterioration rate on engine thrust and thrust specific fuel consumption (TSFC) is studied. Results obtained show an agreement with literature where reduction in engine thrust and TSFC are observed. Turbine’s fouling has been found to be more severe than erosion in terms of power and efficiency losses. However, in terms of the overall performance, the erosion effect is more severe than fouling.

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Tue-Fee, Kin K., and Arno J. Keinonen. "Full-Scale Maneuvering Tests in Level Ice of Canmar Kigoriak and Robert LeMeur." Marine Technology and SNAME News 23, no. 02 (April 1, 1986): 131–38. http://dx.doi.org/10.5957/mt1.1986.23.2.131.

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This paper gives an overview of the extensive full-scale maneuvering tests carried out during the period of September 1979 to July 1980 and May to June 1981 on the icebreaker Canmar Kigoriak and during November to December 1982 and June 1983 on the Robert LeMeur. The icebreakers with spoon-shaped bow and reamers perform well, with the Robert LeMeur rivalling and Kigoriak surpassing the performance of conventional Canadian icebreakers of comparable size and power. The effects of heel on the turning performance of the ships were tested and are discussed. Due to the proprietary nature of the full-scale data, only some of the results are presented in this paper.

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DIJKSTRA, TON, BÉRYL HILBERINK-SCHULPEN, and WALTER J. B. VAN HEUVEN. "Repetition and masked form priming within and between languages using word and nonword neighbors." Bilingualism: Language and Cognition 13, no. 3 (January 19, 2010): 341–57. http://dx.doi.org/10.1017/s1366728909990575.

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If access to the bilingual lexicon takes place in a language independent way, monolingual repetition and masked form priming accounts should be directly applicable to bilinguals. We tested such an account (Grainger and Jacobs, 1999) and extended it to explain bilingual effects from L2 to L1. Dutch–English bilinguals made a lexical decision on a Dutch target word preceded by a briefly presented word or nonword prime from Dutch (L1; Exp. 1) or English (L2; Exp. 2). The prime was an orthographically related neighbor of the target (e.g., zwaar–ZWAAN or spoon–SPION) or unrelated (e.g., thuis–ZWAAN or mouse–SPION). On their first presentation, responses to L1 word targets were non-significantly slowed relative to unrelated primes following both L1 and L2 related word primes. Upon target repetition, all effects turned into facilitation. Stable facilitation effects were also found when word targets were preceded by related nonwords derived from Dutch or English words. Simulations by the Bilingual Interactive Activation Plus (BIA+) model account for the major effects within and across languages.

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Saarti, Jarmo. "Feeding with the spoon, or the effects of shelf classification of fiction on the loaning of fiction." Information Services & Use 17, no. 2-3 (April 1, 1997): 159–69. http://dx.doi.org/10.3233/isu-1997-172-312.

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Lobo, Bianca, Fernando Schnaid, Marcelo Rocha, and John Howie. "Shear strength of granular soils from the simulation of dynamic penetration tests." Journal of Geo-Engineering Sciences 2, no. 3,4 (July 17, 2015): 143–58. http://dx.doi.org/10.3233/jgs-140028.

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Abstract This paper presents a model for the numerical simulation of dynamic penetration tests in cohesionless soils. In the model, dynamic penetration equations are solved by finite difference analysis in the time domain to produce the discretization of the penetration system. The approach allows essential effects of the soil influence to be accounted for, including the dynamic soil resistance by viscous damping during penetration. The model performance has proved by comparisons between the static and dynamic resistance to reproduce the variation with time of measured force, velocity, displacement and energy associated with the interaction mechanism around split-spoon samplers when penetrating in the ground. A realistic representation of the dynamic penetration mechanism allows the internal friction angle of the soil to be estimated. The proposed methodology accounts for scale effects and produces values of φ′ within the same order of magnitude as those estimated from piezocone test data.

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Basavaraj, Hubballi, and Sondur Vilas. "Theoretical analysis of steady state operating forces in control valves." MATEC Web of Conferences 144 (2018): 01002. http://dx.doi.org/10.1051/matecconf/201814401002.

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The controlling components, such as valves are used to regulate controlled fluid power. It is not always possible to calculate valve forces accurately, and with some types of valves even the existence of certain types of forces cannot be predicted with certainty. In many cases, however, the analysis can be made fairly completely and accurately. The assumption of steady state conditions is valid for the valve alone, but transient effects in the rest of the system may be large. These effects are particularly important with regard to the instability of valves, where the system may react on the valve in such a way as to make it squeal or oscillate, sometimes with large amplitude. The origin of the steady state flow force understood from a brief qualitative explanation. The following paper will summarize much of what is known about valve forces in the spool type controlling element.

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MacLeod, J. D., V. Taylor, and J. C. G. Laflamme. "Implanted Component Faults and Their Effects on Gas Turbine Engine Performance." Journal of Engineering for Gas Turbines and Power 114, no. 2 (April 1, 1992): 174–79. http://dx.doi.org/10.1115/1.2906567.

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Under the sponsorship of the Canadian Department of National Defence, the Engine Laboratory of the National Research Council of Canada (NRCC) has established a program for the evaluation of component deterioration on gas turbine engine performance. The effect is aimed at investigating the effects of typical in-service faults on the performance characteristics of each individual engine component. The objective of the program is the development of a generalized fault library, which will be used with fault identification techniques in the field, to reduce unscheduled maintenance. To evaluate the effects of implanted faults on the performance of a single spool engine, such as an Allison T56 turboprop engine, a series of faulted parts were installed. For this paper the following faults were analyzed: (a) first-stage turbine nozzle erosion damage; (b) first-stage turbine rotor blade untwist; (c) compressor seal wear; (d) first and second-stage compressor blade tip clearance increase. This paper describes the project objectives, the experimental installation, and the results of the fault implantation on engine performance. Discussed are performance variations on both engine and component characteristics. As the performance changes were significant, a rigorous measurement uncertainty analysis is included.

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Journal articles on the topic 'Spoof effects'

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