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131.
ABSTRACT Moisture diffusivity is the most crucial property in drying calculations. Literature data are scarce due to the variation of both experimental measurement techniques and methods of analysis. The effect of using different methods of analysis on the same experimental drying data is examined in this work. Detailed and simplified mathematical models, incorporating moisture diffusivity as model parameter, are applied. It is proved, that significant differences in the calculated values of moisture diffusivity result when different models are used, and probably these differences explain the variation in literature data. Thus, the adoption of a standardised methodology will be of great importance in moisture diffusivity evaluation. The above findings resulted from the application of four alternative models on the drying data of three common food materials, potato, carrot and apple. A typical pilot plant scale dryer with controlled drying air conditions was used for the experiments. The moisture content dependence of the diffusion coefficient was proved significant at the last drying stage, while the temperature dependence followed the well known Arrhenius relation. The effects of considering external mass transfer and volume shrinkage during drying, were also investigated. 相似文献
132.
<正>如今,随着集成功能的不断增加,移动电话还可作为便携式媒体播放器(PMP)、数码相机、掌上电脑(PDA)、甚至全球定位系统(GPS)使用。如何获得更加逼真的显示、突破热瓶颈、高效智能地管理电源是系统设计人员当前面临的挑战。 相似文献
133.
Jerry Ray Dias 《Polycyclic Aromatic Compounds》2013,33(3-4):359-377
The important concepts of a formula periodic table set, aufbau principle, elementary substructures, excised internal structure/circumscribing algorithm, leapfrog algorithm, and hexagonal-to-pentagonal ring contraction algorithm will be reviewed. These concepts have been instrumental in organizing polyhex/polypent systems from benzenoid hydrocarbons to fullerene carbons. Some recent experimental verification of our prior predictions in this work will be noted. 相似文献
134.
Abstract The effect of drying conditions on color changes of apple, banana, carrot and potato during conventional and vacuum drying was investigated. The Hunder color scale parameters redness, yellowness and lightness were used to estimate color changes during vacuum and conventional drying at 50, 70 and 90°C. Air humidity during conventional drying was regulated at 15, 30 and 40%. Air temperature and humidity affected redness and yellowness, but not lightness. A first order kinetic model was fitted to experimental data adequately for both redness and yellowness. The rate of color deterioration was found to increase as temperature increased and air humidity decreased, for both drying methods and all the examined materials. 相似文献
135.
ABSTRACT Drying kinetics of volatile organic solvents have been examined during the drying process of a pharmaceutical coating containing a multicomponent mixture of ethyl acetate, n-heptane, propanol-2, and toluene. A complete set of experiments was performed in two drying apparatuses, a laboratory air-dryer and an oven dryer, for a wide range of drying temperature, air velocity, initial coating thickness and drying time. An empirical kinetic model is used to predict the concentration of each organic solvent in the mixture during the drying process. The results show that both drying conditions and sample characteristics affect significantly the drying rate of solvents. 相似文献
136.
137.
The purpose of this paper is to describe the use of a minicomputer in an integrated track inspection program. The basic elements of such a program include the measuring vehicle, data reduction process, and presentation of data to the various management levels. The paper describes such a system which has been in use on the Southern Railway for over five years and points out desirable changes, problems, and economics. 相似文献
138.
For the fuzzy weighted average (FWA), despite various discrete solution algorithms and their improvements, attempts at analytical solutions are very rare. This paper provides an analytical solution method for the FWA based on the conclusions of the Karnik–Mendel (KM) algorithm. Compared with the two current popular kinds of α-cut based computational methods for the FWA (mathematical programming transformations and direct iterate computations), our method is precise, and, has a concise structure, efficient computation process, and sound theoretical proofs. We propose two algorithms for computing the analytical solution of the FWA. Two numerical examples illustrate our proposed approach. 相似文献
139.
140.
Jerry Ray Dias 《Polycyclic Aromatic Compounds》2013,33(1-4):83-91
Two 2-dimensional tableaus of heterocyclic molecular systems are shown to have molecular graphs that are pairwise strongly subspectral (having a preponderance of common eigenvalues). Based on this result, the electronic similarity of candidate chromophores are proposed. 相似文献