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51.
The main objective of the paper is to establish an arrangement of sources of exergy losses (internal and external ones) and to estimate the value of the losses in an industrial ozone production installation. An exergetic model of industrial installation in a system approach corresponding to real conditions has been formulated.  相似文献   
52.
An analysis of the solute dispersion in the liquid flowing through a pipe by means of Aris-Barton's ⒈method of moments',under the joint effect of some finite yield stress and irreversible absorption into the wall is presented in this paper.The liquid is considered as a three-layer liquid where the center region is Casson liquid surrounded by Newtonian liquid layer.A significant change from previous modelling exercises in the study of hydrodynamic dispersion,different molecular diffusivity has been considered for the different region yet to be constant.For all time period,finite difference implicit scheme has been adopted to solve the integral moment equation arising from the unsteady convective diffusion equation.The purpose of the study is to find the dependency of solute transport coefficients on absorption parameter,yield stress,viscosity ratio,peripheral layer variation and in addition with various diffusivity coefficients in different liquid layers.This kind of study may be useful for understanding the dispersion process in the blood flow analysis.  相似文献   
53.
The deformation behavior of rubber-toughened polymer, which was prepared by incorporating soft, core-shell rubbery particles into a glassy polymer such as poly (methyl methacrylate) (PMMA), has been investigated by means of mechanical tests, optical monitoring (OM), and scanning electron microscopy (SEM). By mechanical testing, the neat PMMA reveals a 2% strain with high yield stress. After inclusion of 17.5 and 35 vol%rubber particles, the softened-PMMA samples exhibit corresponding strain of 20% and 38%, showing an increase of strain along with the relative decrease of yield stress, resulting in a toughening behavior of PMMA. Clear shear bands and stress whitening develop in the rubber-toughened PMMA after deformation, as observed by OM. Investigation by SEM shows crazes/cracks in the stretched, rubber-softened PMMA samples in which the core-shell particles are found to be cavitated. The mechanism of this deformation has been explained based on the void formation in the rubbery shell as well as the initiation and propagation of crazing.  相似文献   
54.
Abstract

The yellowish color of High Yield Pulp (HYP) gives some psychological obstacles and limits its application in some paper grades. Dyes are widely used in the papermaking process to shade the yellowish color of the paper products. We proposed to add dyes into the HYP manufacturing process to minimize the yellowish hue. In this work, we substituted the dye-added HYP (dyes added in the HYP manufacturing process) for hardwood kraft pulp in the production of fine paper grades, and compared the results from those by adding dyes into the papermaking wet end. A higher dye effectiveness was obtained when we used the dye-added HYP. Also, the dye-added HYP gave more effective performance of Precipitated Calcium Carbonate (PCC) fillers and Optical Brightening Agents (OBA) in terms of CIE whiteness and b*. In addition, the dye-added HYP showed less negative effect on brightness and better compatibility with other dyes. The underlying mechanism for the above experimental observation was proposed.  相似文献   
55.
采用碱溶和酸洗过程对合成的MOR沸石进行骨架脱硅与介孔改性。结果表明,碱溶-酸洗联合处理促进 MOR 骨架选择性脱硅和晶内介孔的形成;脱硅沸石的相对结晶度和产率随介孔率的增加呈下降趋势。辅以酸洗可调整碱处理沸石的硅铝比,改进其酸强度分布和介孔率。  相似文献   
56.
In order to control the large deformation of tunnel surrounding rock, a new energy-absorbing bolt is developed. This bolt can be transformed into a rigid support when the deformation of the surrounding rock reaches the length of the sleeve tube, thus preventing the surrounding rock from continuing to deform. Moreover, this bolt has a simple structure and is easy to manufacture and assemble. Then the static tensile test is conducted on the bolt specimen to test its working performance. The test results show that when the cone angle of the cone block is small, the load–displacement curve of the bolt contains three stages; when the cone angle is large, the load–displacement curve contains only two stages. Meanwhile, both the average constant resistance and the maximum absorbed energy increase linearly with the increase of cone angle. On this basis, ignoring the influence of shear stress, and it is supposed that the thickness of the sleeve tube is constant, then the theoretical calculation formula of constant resistance for the new bolt is derived, and the rationality of the formula is verified using the static tensile test results. It is found that the error of the calculated result is less than 15% when the cone angle does not exceed 15°. At last, the numerical simulation method is used to analyze the performance of the new bolt. The simulation results indicate that the generation of shear stress and the change of tube thickness during the movement of the cone block are two important factors that cause theoretical errors.  相似文献   
57.
In some of the coalfields in India, coal seams are only developed but no extraction of pillars is possible due to the presence of surface or sub-surface structures and also non-availability of stowing materials which leads to huge amounts of coal being locked-up underground. Spontaneous heating and fire, accumulation of poisonous gases, severe stability issues leading to unsafe workings and environmental hazards are the major problems associated with the developed coal pillars. So, there is a pressing need for a technology for the mining industry to extract the huge amount of coal locked-up under different constraints. In this study, the locked-up coal is proposed to be extracted by artificially strengthening the rib pillars. The detailed comparative study is carried out to know the increase of extraction percentage of locked-up coal by strengthening the rib pillars with FRP. Extraction methodology is designed and studied through numerical modelling for its stability analysis to evaluate its suitability of application in underground.  相似文献   
58.
张春林 《辽宁化工》2005,34(9):412-413
针对富马酸重结晶过程中,漂浮物太多,产品粒度太小,已经不能适应现有生产方式,导致重结晶收率低;改进重结晶工艺,使结晶收率达到95%以上,降低劳动强度,节能效果明显,质量明显改善。  相似文献   
59.
Electrorheological (ER) response of biocompatible particles suspended in an insulating silicone oil, was investigated under several different applied external electric field strengths. Chitosan, a biodegradable polysaccharide, was used as anhydrous ER materials. The effect of particle volume concentration on their ER response was examined by focusing on the measurement for rheological and electrical properties. The yield stress of chitosan suspended in silicone oil system as a function of applied electric field strength showed different value of slopes for different particle concentrations, however, all data points collapse onto a universal scaling function.  相似文献   
60.
成海涛 《钢管》2000,29(2):10-14
分析了周期轧管机组的工艺特点 ,指出影响周期轧管机组金属收得率的原因 ,提出了提高周期轧管机组成材率的途径。  相似文献   
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