The Experts below are selected from a list of 70800 Experts worldwide ranked by ideXlab platform
Karim Allaf - One of the best experts on this subject based on the ideXlab platform.
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Quality studies on various types of partially dried vegetables texturized by Controlled Sudden Decompression: General patterns for the variation of the Expansion Ratio
2004Co-Authors: Nicolas Louka, Frédéric Juhel, Karim AllafAbstract:Abstract Quality of dried vegetables texturized by Controlled Sudden Decompression (Detente Instantanee Controlee DIC®) was studied through the Expansion Ratio, the color and the degree of cooking. This study was realized as a function of the four main experimental parameters: saturated steam pressure, treatment time, water content of the product before treatment and the thickness of the pieces of the raw product. These parameters are of primary importance in determining the quality of the final product. The behavior of the matter vis-a-vis the treatments was also investigated. It was found that pressure had the highest effect with final product volumes being 2.2–4.5 times those after drying with hot air only. An optimum treatment time of 25 s was defined although for potato, with a denser structure, it was 45 s. General patterns for the variation in Expansion Ratio as a function of the operating parameters are proposed.
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Expansion Ratio and color improvement of dried vegetables texturized by a new process controlled sudden decompression to the vacuum application to potatoes carrots and onions
2004Co-Authors: Nicolas Louka, Karim AllafAbstract:A procedure, Controlled Sudden Decompression (Detente Instantanee Controlee DIC®) has been developed to impart a porous structure to partially dried pieces of food by expanding them. In this paper, the DIC cycle was optimized for use with special food products. The establishment of an initial vacuum phase prior to the steam treatment, a treatment by step-wise increases in temperature and an atmospheric air injection phase enabled us to process product pieces in a thick layer, very heat-sensitive products or other food products with a low hardening temperature. The physical attributes evaluated were the Expansion Ratio and color of three vegetables: potatoes, carrots and onions.
Surajit Kumar Paul - One of the best experts on this subject based on the ideXlab platform.
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A critical review on hole Expansion Ratio
2020Co-Authors: Surajit Kumar PaulAbstract:Abstract Materials resistance to edge fracture in intricate shape forming is commonly quantified by hole Expansion Ratio (HER). Hole Expansion test is normally used to evaluate HER. To date, the governing factors of HER have not well understood regardless of its importance for automotive part manufacturing with advanced high-strength steels. The present paper comprehensively discussed the recent progress on HER, including fundamental deformation aspects, the effect of punch geometries, correlation with tensile properties, and the influence of microstructure. This reviewed work explains why HER is currently an essential topic of engineering research.
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non linear correlation between uniaxial tensile properties and shear edge hole Expansion Ratio
2014Co-Authors: Surajit Kumar PaulAbstract:Stretch flanging of steel sheets is an important formability issue for automobile industry. Finite element simulation study confirms that the edge of the hole deforms in a uniaxial tensile manner during the hole Expansion process. To understand the effect of various tensile properties on hole Expansion Ratio, current experimental data and collected data from published work have been used. Yield stress, ultimate tensile stress, coefficient of normal anisotropy, total elongation, and post uniform elongation are closely related to hole Expansion Ratio. A non-linear relationship between hole Expansion Ratio and tensile properties (ultimate tensile stress, coefficient of normal anisotropy, and total elongation) is developed in the present investigation.
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Prediction of hole Expansion Ratio for automotive grade steels
2014Co-Authors: Surajit Kumar Paul, Monideepa Mukherjee, Saurabh Kundu, Sanjay ChandraAbstract:Abstract The objective of this work is to characterize experimentally and predict analytically the hole Expansion Ratio of steel sheets from uniaxial tensile properties. Firstly, finite element analysis is performed to understand the deformation modes (i.e. stress state) at the edge of the hole during its Expansion by a conical punch. Finite element simulation study confirms that during the hole Expansion process, the edge of the hole undergoes uniaxial tensile deformation. Secondly, a fracture based failure criterion is employed to predict the hole Expansion Ratio, considering that the test stop criteria of the hole Expansion process is the formation of a through thickness crack. Next, a methodology is proposed to compute the true fracture strain during uniaxial tensile test, following which a model is proposed to predict the hole Expansion Ratio analytically from the true fracture strain. The proposed model is validated with eight different steel grades.
Nicolas Louka - One of the best experts on this subject based on the ideXlab platform.
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Quality studies on various types of partially dried vegetables texturized by Controlled Sudden Decompression: General patterns for the variation of the Expansion Ratio
2004Co-Authors: Nicolas Louka, Frédéric Juhel, Karim AllafAbstract:Abstract Quality of dried vegetables texturized by Controlled Sudden Decompression (Detente Instantanee Controlee DIC®) was studied through the Expansion Ratio, the color and the degree of cooking. This study was realized as a function of the four main experimental parameters: saturated steam pressure, treatment time, water content of the product before treatment and the thickness of the pieces of the raw product. These parameters are of primary importance in determining the quality of the final product. The behavior of the matter vis-a-vis the treatments was also investigated. It was found that pressure had the highest effect with final product volumes being 2.2–4.5 times those after drying with hot air only. An optimum treatment time of 25 s was defined although for potato, with a denser structure, it was 45 s. General patterns for the variation in Expansion Ratio as a function of the operating parameters are proposed.
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Expansion Ratio and color improvement of dried vegetables texturized by a new process controlled sudden decompression to the vacuum application to potatoes carrots and onions
2004Co-Authors: Nicolas Louka, Karim AllafAbstract:A procedure, Controlled Sudden Decompression (Detente Instantanee Controlee DIC®) has been developed to impart a porous structure to partially dried pieces of food by expanding them. In this paper, the DIC cycle was optimized for use with special food products. The establishment of an initial vacuum phase prior to the steam treatment, a treatment by step-wise increases in temperature and an atmospheric air injection phase enabled us to process product pieces in a thick layer, very heat-sensitive products or other food products with a low hardening temperature. The physical attributes evaluated were the Expansion Ratio and color of three vegetables: potatoes, carrots and onions.
Lei Zhang - One of the best experts on this subject based on the ideXlab platform.
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fabrication of high Expansion microcellular pla foams based on pre isothermal cold crystallization and supercritical co2 foaming
2018Co-Authors: Guoqun Zhao, Lei Zhang, Guilong Wang, Jie GongAbstract:Abstract Poly(lactic acid) (PLA) is a kind of bio-based and biodegradable polymers. PLA foams with high Expansion Ratio have great application potential in heat insulation, adsorption and other areas. However, due to its low melt strength and slow crystallization rate, linear PLA has poor foaming ability, so it is hard to prepare PLA foams with high Expansion Ratio. Although chain branching, blending, and other methods have been utilized to improve PLA's melt strength and foaming ability, they easily destroy PLA's biodegradability, cause chemical pollution, and raise production costs. In this study, a new supercritical fluid foaming process, based on pre-isothermal cold crystallization, was proposed to prepare PLA foams with high Expansion Ratio. To improve PLA's melt strength and foaming ability, a pre-isothermal treatment was applied to induce sufficient cold crystallization. According to the SEM results, the cold crystallization of PLA becomes more sufficient and the crystal morphology becomes more perfect with the pre-isothermal treating. The DSC and WAXD results confirm that, the pre-isothermal treatment remarkably promotes the PLA's cold crystallization, and endows the PLA sample higher crystallinity and more perfect crystalline structure. Moreover, the high-pressure rheology testing results indicate that the pre-isothermal treatment improves the PLA's melt viscoelasticity significantly. Finally, the foaming results show that the pre-isothermal treatment significantly enhances the PLA's foaming ability. With the pre-isothermal treatment, the PLA's maximum Expansion Ratio increases from 6.40-fold to 17.7-fold, and the uniformity of cellular structure is also improved obviously. The new process provides a green, flexible, and low-cost way to prepare fully biodegradable PLA foams with high Expansion Ratio.
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Design Optimization of A Small Scale High Expansion Ratio Organic Vapour Turbo Expander for Automotive Application
2017Co-Authors: Qiyu Ying, Wei Lin Zhuge, Yangjun Zhang, Lei ZhangAbstract:Abstract Environmental concern on a global scale and the concept of energy conservation in heavy duty trucks nowadays have attracted the increasing attention among researchers on the automotive waste heat recovery applications based on Organic Rankine Cycle (ORC) system. However, the system efficiency is theoretically low because of comparatively small temperature difference between exhaust gas and atmosphere, which brings about increasing Expansion Ratio as a feasible method to improve system performance. However, turbo expander, the most significant component in the system, might generate huge losses due to supersonic flow caused by high Expansion Ratio, therefore study on supersonic organic vapor turbo expander design emerged as required. In this paper, a single-stage radial-inflow organic vapor turbo expander with pressure-Ratio up to 8 is preliminarily designed, and its performance and internal flow are numerically studied. The performance is simulated with three dimensional computational fluid dynamic (CFD) method at operating conditions. Several geometry modifications are conducted in order to learn their influence on turbine performance. Shock waves and trailing edge losses are observed as main losses in the nozzles. In addition, flow sepaRations are the main losses in the rotors. Turbine blade is accordingly optimized after the analysis, and the nozzle total pressure loss coefficient decrease clearly, meanwhile a rise of 3.4% on turbine efficiency can be obtained. Shock waves and reflected waves are suppressed, and a more uniform stream at nozzle outlet can be observed.
Milford A. Hanna - One of the best experts on this subject based on the ideXlab platform.
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screw configuRation effects on corn starch Expansion during extrusion
1994Co-Authors: Avtar S Sokhey, Anantha N R Kollengode, Milford A. HannaAbstract:Normal corn starch was extrusion cooked in a Brabender single-screw extruder. Three screws with no mixing, one mixing or two mixing elements were used to extrude the samples through a 3 mm cylindrical die nozzle at 140°C barrel temperature and 140 rpm screw speed. Dependent variables included overall and radial Expansion Ratios, bulk density and specific mechanical energy (SME). Extrudates were ground and re-extruded using the same three screws, and the same extrusion conditions. Significant differences (P < 0.05) in bulk density, SME and radial Expansion Ratio were found on re-extrusion. No changes occurred in overall Expansion Ratio (P < 0.05).
