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111.
Arman Arefi Parviz Ahmadi Moghaddam Kaveh Mollazade Ali Hassanpour Constantino Valero Aoife Gowen 《Comprehensive Reviews in Food Science and Food Safety》2015,14(5):657-680
Mealiness is known as an important internal quality attribute of fruits/vegetables, which has significant influence on consumer purchasing decisions. Mealiness has been a topic of research interest over the past several decades. A number of destructive and nondestructive techniques are introduced for mealiness detection. Nondestructive methods are more interesting because they are rapid, noninvasive, and suitable for real‐time purposes. In this review, the concept of mealiness is presented for potato, apple, and peach, followed by an in‐depth discussion about applications of destructive and nondestructive techniques developed for mealiness detection. The results suggest the potential of electromagnetic‐based techniques for nondestructive mealiness evaluation. Further investigations are in progress to find more appropriate nondestructive techniques as well as cost and performance. 相似文献
112.
Nonlinear thermoelastic analysis of thick-walled functionally graded piezoelectric cylinder 总被引:1,自引:0,他引:1
Mohammad Arefi 《Acta Mechanica》2013,224(11):2771-2783
This research addresses the nonlinear behavior of a functionally graded piezoelectric (FGP) cylinder under thermal, mechanical and electrical loads. Except the Poisson ratio, the other thermal, mechanical and electrical properties vary continuously along the thickness direction. The geometric nonlinearity was considered in strain–displacement relation. The present paper proposes a novel analytical method for estimating the response of the systems of nonlinear differential equations. The proposed method is modification and combination of Adomian’s decomposition and successive approximation methods. The governing nonlinear differential equations were solved using the proposed analytical method. The nonlinear solutions were presented for different values of nonhomogenous index. For validation of the results and justifying the necessity of the present study, the present results were compared with results obtained using the linear analysis. Due to using the functionally graded cylinder in serious environments such as chemical and weapon equipments or adjustable and precise condition, a nonlinear analysis for these materials is necessary. A nonlinear analysis improves the results significantly. A maximum of 5% improvement for electric potential and 9% for radial displacement were attained employing this nonlinear analysis rather than a linear analysis. These considerable improvements can present a confidence and adjustable tool for manufacturing and design of sensors and actuators with better accuracy. 相似文献
113.
114.
In this research, ablation resistance of Cf-C-SiC and Cf-C-SiC-Ti3SiC2 composites, fabricated by liquid silicon infiltration (LSI) method were investigated. The infiltration process was conducted at 1500?°C for 30?min and then the samples were annealed at 1350?°C. X-ray diffraction (XRD) technique and scanning electron microscopy (SEM) were utilized in order to investigate the phase composition and microstructure of the ablated samples, respectively. When compared with Cf-C-SiC composite, results showed that mass and linear ablation rates of Cf-C-SiC-Ti3SiC2 composite have been improved by 50% and 37.5%, respectively. The mass and linear ablations rates of Cf-C-SiC composite were reached to 23.8?mg/s and 0.096?mm/s, respectively, while these values for Cf-C-SiC-Ti3SiC2 were reached to 11.8?mg/s and 0.06?mm/s, respectively. Microscopic investigations showed that formation of protective oxide layer and its stability on the surface of MAX-containing composite are the main reasons for improvement of ablation properties. While the oxide film formed on Cf-C-SiC composite has been blown away by flame. 相似文献
115.
Journal of Superconductivity and Novel Magnetism - Perovskite La0.85Ce0.15FeO3 was synthesized with crystallite size 23 nm by flash combustion technique. The obtained sample was... 相似文献
116.
Rolf Berghammer Weiping Hu Arman Hasani Günter Gottstein 《Advanced Engineering Materials》2011,13(4):232-236
Ultrafine grained material was produced by equal channel angular pressing and confined channel die pressing. Microstructure and mechanical properties of the obtained samples were compared. The different effects on microstructure evolution and mechanical properties from both processes are discussed. 相似文献
117.
A Novel Solution for Stochastic Dynamic Game of Water Allocation from a Reservoir Using Collocation Method 总被引:2,自引:2,他引:0
In this study, a continuous model of stochastic dynamic game for water allocation from a reservoir system was developed. The continuous random variable of inflow in the state transition function was replaced with a discrete approximant rather than using the mean of the random variable as is done in a continuous model of deterministic dynamic game. As a result, a new solution method was used to solve the stochastic model of game based on collocation method. The collocation method was introduced as an alternative to linear-quadratic (LQ) approximation methods to resolve a dynamic model of game. The collocation method is not limited to the first and second degree approximations, compared to LQ approximation, i.e. Ricatti equations. Furthermore, in spite of LQ related problems, consideration of the stochastic nature of game on the action variables in the collocation method would be possible. The proposed solution method was applied to the real case of reservoir operation, which typically requires considering the effect of uncertainty on decision variables. The results of the solution of the stochastic model of game are compared with the results of a deterministic solution of game, a classical stochastic dynamic programming model (e.g. Bayesian Stochastic Dynamic Programming model, BSDP), and a discrete stochastic dynamic game model (PSDNG). By comparing the results of alternative methods, it is shown that the proposed solution method of stochastic dynamic game is quite capable of providing appropriate reservoir operating policies. 相似文献
118.
Arman Shehabi Srirupa Ganguly Lara A. Gundel Arpad Horvath Thomas W. Kirchstetter Melissa M. Lunden William Tschudi Ashok J. Gadgil William W. Nazaroff 《Building and Environment》2010
Economizer use in data centers is an energy efficiency strategy that could significantly limit electricity demand in this rapidly growing economic sector. Widespread economizer implementation, however, has been hindered by potential reliability concerns associated with exposing information technology equipment to particulate matter of outdoor origin. This study explores the feasibility of using economizers in data centers to save energy while controlling particle concentrations with high-quality air filtration. Physical and chemical properties of indoor and outdoor particles were analyzed at an operating northern California data center equipped with an economizer under varying levels of air filtration efficiency. Results show that when improved filtration is used in combination with an economizer, the indoor/outdoor concentration ratios for most measured particle types were similar to levels when using conventional filtration without economizers. An energy analysis of the data center reveals that, even during the summer months, chiller savings from economizer use greatly outweigh any increase in fan power associated with improved filtration. These findings indicate that economizer use combined with improved filtration could reduce data center energy demand while providing a level of protection from particles of outdoor origin similar to that observed with conventional design. 相似文献
119.
This paper suggests a method based on stochastic multi-objective modelling for optimally siting and sizing of distributed generations and capacitors and simultaneously network reconfiguration, in order to take more advantages of recent developed technologies. With respect to the widespread effect of uncertainties of load forecasting and market price, some strategies must be devised so as to well incorporate them into the problem. The mentioned problem can be regarded as a multi-objective optimisation problem for which NSGA-II accompanied by fuzzy set theory are chosen. The main aim of DisCo is to provide highly reliable power at the lowest possible costs. Besides, voltage deviation and voltage stability as the criteria of power quality in distribution networks and emission pollutant reduction are treated as independent objective functions. Eventually, to validate the effectiveness of the proposed scheme, simulations are carried out and the results are compared to the initial configuration. 相似文献
120.
Akbar Heydari Afsaneh Arefi Samad Khaksar Mahmoud Tajbakhsh 《Catalysis communications》2006,7(12):982-984
A simple method is described for the synthesis of α-hydroxy phosphonates by reaction of aldehydes with trimethylphosphite in the presence of guanidine hydrochloride (5 mol%) in water at 50 °C. 相似文献