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Material Density (material + density)
Selected AbstractsChemical-Picture-Based Modeling of Thermodynamic Properties of Dense Multicharged-Ion Plasmas Using the Superconfiguration ApproachCONTRIBUTIONS TO PLASMA PHYSICS, Issue 10 2009P.A. Loboda Abstract Using the chemical-picture representation of plasmas as a mixture of various ions and free electrons, a consistent description of thermodynamics of dense multicharged-ion plasmas is being developed that involves the effects of Coulomb non-ideality and degeneracy of plasma electrons; contribution of the excited ion states (on the base of the superconfiguration approach) that may exist under an appropriate truncation of ion energy spectra due to plasma effects; hard-sphere-model representation of the finite-volume effects of plasma ions with the model parameters (effective ion sizes) corresponding to superconfigurations yielding the greatest contribution to partition functions. We present the calculated data for average ionization, Grüneisen coefficient, and specific heat of aluminum and iron plasmas at temperatures of 0.03,3 keV and densities 10,3 , 10,5 of their normal material densities. Calculated thermodynamic functions and shock Hugoniots are compared with other theoretical and experimental data (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Method of calculation of heat transfer coefficient of the heater in a circulating fluidized bed furnaceHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 7 2002J.F. Lu Abstract Knowledge of heat transfer coefficients is important in the design and operation of CFB boilers. It is the key to determining the area and the layout of the heat transfer surfaces in a CFB furnace. Local bulk density has a close relationship to the local heat transfer coefficient. Using a heat flux probe and bulk density sampling probe, the local bed to wall heat transfer coefficient in the furnace of a 75 t/h CFB boiler was measured. According to the experimental results and theoretical analysis of the facts that influence the heat transfer, the heat transfer coefficient calculation method for the CFB furnace was developed. The heat transfer surface configuration, heating condition, and the material density are considered in this method. The calculation method has been used in the design of CFB boilers with a capacity from 130 t/h to 420 t/h. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 31(7): 540,550, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10056 [source] Bond rolling resistance and its effect on yielding of bonded granulates by DEM analysesINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 8 2006M. J. Jiang Abstract A discrete element modelling of bonded granulates and investigation on the bond effect on their behaviour are very important to geomechanics. This paper presents a two-dimensional (2-D) discrete element theory for bonded granulates with bond rolling resistance and provides a numerical investigation into the effect of bond rolling resistance on the yielding of bonded granulates. The model consists of mechanical contact models and equations governing the motion of bonded particles. The key point of the theory is that the assumption in the original bond contact model previously proposed by the authors (55th CSCE-ASCE Conference, Hamilton, Ont., Canada, 2002; 313,320; J. Eng. Mech. (ASCE) 2005; 131(11):1209,1213) that bonded particles are in contact at discrete points, is here replaced by a more reliable assumption that bonded particles are in contact over a width. By making the idealization that the bond contact width is continuously distributed with the normal/tangential basic elements (BE) (each BE is composed of spring, dashpot, bond, slider or divider), we establish a bond rolling contact model together with bond normal/tangential contact models, and also relate the governing equations to local equilibrium. Only one physical parameter , needs to be introduced in the theory in comparison to the original bond discrete element model. The model has been implemented into a 2-D distinct element method code, NS2D. Using the NS2D, a total of 86 1-D, constant stress ratio, and biaxial compressions tests have been carried out on the bonded granular samples of different densities, bonding strengths and rolling resistances. The numerical results show that: (i) the new theory predicts a larger internal friction angle, a larger yielding stress, more brittle behaviour and larger final broken contact ratio than the original bond model; (ii) the yielding stress increases nonlinearly with the increasing value of ,, and (iii) the first-yield curve (initiation of bond breakage), which define a zone of none bond breakage and which shape and size are affected by the material density, is amplified by the bond rolling resistance in analogous to that predicted by the original bond model. Copyright © 2006 John Wiley & Sons, Ltd. [source] Dielectric properties of pharmaceutical materials relevant to microwave processing: Effects of field frequency, material density, and moisture contentJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 2 2010Paul W.S. Heng Abstract The rising popularity of microwaves for drying, material processing and quality sensing has fuelled the need for knowledge concerning dielectric properties of common pharmaceutical materials. This article represents one of the few reports on the density and moisture content dependence of the dielectric properties of primary pharmaceutical materials and their relevance to microwave-assisted processing. Dielectric constants and losses of 13 pharmaceutical materials were measured over a frequency range of 1,MHz,1,GHz at 23,±,1°C using a parallel-electrode measurement system. Effects of field frequency, material density and moisture content on dielectric properties were studied. Material dielectric properties varied considerably with frequency. At microwave frequencies, linear relationships were established between cube-root functions of the dielectric parameters ( and ) and density which enabled dielectric properties of materials at various densities to be estimated by regression. Moisture content was the main factor that contributed to the disparities in dielectric properties and heating capabilities of the materials in a laboratory microwave oven. The effectiveness of a single frequency density-independent dielectric function for moisture sensing applications was explored and found to be suitable within low ranges of moisture contents for a model material. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:941,957, 2010 [source] The rotational molding of a thermotropic liquid crystalline polymerPOLYMER ENGINEERING & SCIENCE, Issue 3 2005Eric Scribben Thermotropic liquid crystalline polymers (TLCPs) exhibit a number of mechanical and physical properties such as excellent chemical resistance, low permeability, low coefficient of thermal expansion, high tensile strength and modulus, and good impact resistance, which make them desirable as a rotationally molded storage vessel. However, there are no reports in the technical literature of the successful rotational molding of TLCPs. In this article, conditions are identified that lead to the successful rotational molding of a TLCP, Vectra B 950. First, a technique was developed to produce particles suitable for rotational molding because TLCPs cannot be ground into a free-flowing powder. Second, because the viscosity at low shear rates can be detrimental to the sintering process, coalescence experiments with isolated particles were carried out to determine the thermal and environmental conditions at which sintering should occur. These conditions were then applied to static sintering experiments to determine whether coalescence and densification of the bulk powder would occur. Finally, the powders were successfully rotationally molded into tubular structures in a single axis, lab-scale device. The density of the molded structure was essentially equivalent to the material density and the tensile strength and modulus were approximately 18 MPa and 2 GPa, respectively. POLYM. ENG. SCI., 45:410,423, 2005. © 2005 Society of Plastics Engineers [source] Raman Spectroscopy of Laser-Shocked NitrobenzenePROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 6 2002Naoshi Kozu A technique for in situ Raman spectroscopy of laser-shocked nitrobenzene was developed. Raman spectra of shocked nitrobenzene are obtained up to ,3.5,GPa, and peak shifts at particular frequencies are observed. The shifts are plotted as a function of density and compared with the data under isothermal compression. Both data provide the same results. This indicates that the numbers of peak shifts of nitrobenzene depend solely on material density. [source] | |||||||||||||