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排序方式: 共有902条查询结果,搜索用时 0 毫秒
1.
This study investigates the relationship between the critical surface tension of wetting of celestite and agglomeration recovery as well as the zeta potential in dependence of pH and amount of collector (Na‐Oleate). For this purpose, effects of pH and collector amount on the agglomeration recovery are investigated and zeta potential measurements and Fourier Transform Infrared Spectrophotometer (FTIR) analyses are carried out to determine the adsorption type of Na‐Oleate on celestite surface. The sessile drop technique is used for the measurement of contact angle and determination of the critical surface tension of wetting (YC) of celestite. The maximum agglomeration recovery is obtained at pH 7. The critical surface tension of wetting of celestite is very close to the surface tension of kerosene, which is 25.95 mN/m. Furthermore, at the optimum Na‐Oleate amount of 10 kg/ton, the critical surface tension of wetting of celestite is approximately equal to the surface tension of kerosene. 相似文献
2.
3.
J Zaloudík I Kocák Z Pacovsky P Karásek V Fait H Bartonková M Nekulová 《Canadian Metallurgical Quarterly》1997,43(3):171-172
In the absence of adequate autogenous vein for tibial artery bypass in limb salvage surgery, the use of prosthetic grafts with a distal anastomotic vein cuff or patch has shown promising results. Here, we describe how the Florester Internal Vessel Occluder (Meadox UK, Bedfordshire, UK) can facilitate the construction of a distal anastomotic vein cuff. 相似文献
4.
S. Kar T. Searles E. Lee G. B. Viswanathan H. L. Fraser J. Tiley R. Banerjee 《Metallurgical and Materials Transactions A》2006,37(3):559-566
The development of a set of computational tools that permit microstructurally based predictions for the tensile properties
of commercially important titanium alloys, such as Ti-6Al-4V, is a valuable step toward the accelerated maturation of materials.
This paper will discuss the development of neural network models based on a Bayesian framework to predict the yield and ultimate
tensile strengths of Ti-6Al-4V at room temperature. The development of such rules-based model requires the population of extensive
databases, which in the present case are microstructurally based. The steps involved in database development include producing
controlled variations of the microstructure using novel approaches to heat treatments, the use of standardized stereology
protocols to characterize and quantify microstructural features rapidly, and mechanical testing of the heat-treated specimens.
These databases have been used to train and test neural network models for prediction of tensile properties. In addition,
these models have been used to identify the influence of individual microstructural features on the tensile properties, consequently
guiding the efforts toward development of more robust mechanistically based models. Based on the neural network model, it
is possible to investigate the influence of individual microstructural features on the tensile properties, and in certain
cases these dependencies can point toward unrecognized phenomena. For example, the apparently unexpected trend of increase
in tensile strength with increasing prior β-grain size has led to the determination of the pronounced role of the basketweave microstructure in strengthening these alloys,
especially in case of larger prior β grains.
This article is based on a presentation made in the symposium “Computational Aspects of Mechanical Properties of Materials,”
which occurred at the 2005 TMS Annual Meeting, February 13–17, 2005, in San Francisco, CA, under the auspices of the MPMD-Computational
Materials Science & Engineering (Jt. ASM-MSCTS) Committee. 相似文献
5.
Cemile 《中国化学工程学报》2021,37(9):121-127
In this study,a sequential process (heterotrophic up-flow column and completely mixed membrane bioreactors) was proposed combining advantages of the both processes.The system was operated for 249 days with simulated and real groundwater for nitrate removal at concentrations varying from 25 to 145 mg·L-1 NO3-N.The contribution of heterotrophic process to total nitrate removal in the system was controlled by dozing the ethanol considering the nitrate concentration.By this way,sulfur based autotrophic denitrification rate was decreased and the effluent sulfate concentrations were controlled.The alkalinity requirement in the autotrophic process was produced in the heterotrophic reactor,and the system was operated without alkalinity supplementation.Throughout the study,the chemical oxygen demand in the heterotrophic reactor effluent was (23.7 ± 22) mg·L-1 and it was further decreased to(7.5 ± 7.2) mg·L-1 in the system effluent,corresponding to a 70% reduction.In the last period of the study,the real groundwater containing 145 mg·L-1 NO3-N was completely removed.Membrane was operated without chemical washing in the first 114 days.Between days 115-249 weekly chemical washing was required. 相似文献
6.
D. K. Bhattacharyya M. M. Chakrabarty K. Kar 《European Journal of Lipid Science and Technology》1985,87(7):278-282
Acidolysis reaction of sal fat (Shorea robusta) with palmitic acid has been studied in relation to the operating variables like catalyst system and concentration, reaction temperature and time and molar ratios of reactants with the object of introducing more palmitic acid which is low in sal fat. The results demonstrate that as low as 2.5% and as high as 39% palmitic acid can be introduced in sal fat at the expense of other acids under the influence of various operating conditions. The products obtained differ from original sal fat in respect of chemical composition and slip point. The importance of such study is that there are possibilities of getting plastic fats of diverse properties for edible and industrial uses. 相似文献
7.
Polyaniline doped with nonoxidizing Bronsted acids is recognized as a conducting material, as its electrical conductivity changes with percentage of doping. In the present work, different percentages of doped polyaniline were blended with polyacrylamide and their electrical conductivities as well as the positron annihilation lifetimes were measured. Analysis of data yielded three lifetime components. It was observed that the value of the short lifetime component remained constant for doping concentration, whereas that of the intermediate component τ2 decreased. The relative intensity pertaining to τ2, however, increased with the increase in doped PANI concentration. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 930–933, 2003 相似文献
8.
Yakup Cebeci 《Fuel》2003,82(13):1645-1651
In this study, the kinetics of agglomerate growth in a batch oil agglomeration process has been studied using bituminous coal. The effect of operating variables such as kerosene concentration, pulp density and speed of agitation on the agglomeration process was investigated. It has been found that the second-order kinetic equation describes the growth of agglomerates adequately. The growth of the agglomerates in the oil agglomeration process shows a self-preserving growth. Using this, a characteristic curve has been developed. For the prediction of the size distribution of the agglomerates, the d50 values of the agglomerates must be known. Therefore, a model has been developed by using the kinetic equation for estimation of d50 values of agglomerates for this coal. It was shown that the size distribution of the agglomerates for any levels of the process variables studied can be predicted using the equation of characteristic curve and d50 values. Knowledge obtained from this study will be helpful for technological advancement of this kind of study. 相似文献
9.
In this paper, optimal sets of filter coefficients are searched by a meta-heuristic optimization technique called Harmony Search (HS) algorithm for infinite impulse response (IIR) system identification problem. For different optimization problems, HS algorithm undergoes three basic rules; namely Random Selection (RS), Harmony Memory Consideration (HMC), and Pitch Adjustment (PA) rules, which are inspired from the process that the musicians use to improvise a perfect state of harmony with the consummate skill of blending notes in tune. With the help of the properly selected control parameters, a perfect balance is achieved in exploration and exploitation in searching phases. The detailed analysis of simulation results emphasizes the strength of HS algorithm to find the near-global optimal solution, quality of convergence profile and the speed of convergence while tested against standard benchmark examples for same and reduced order models. 相似文献
10.
Application of the Box-Wilson experimental design method for the spherical oil agglomeration of coal
Yakup Cebeci 《Fuel》2006,85(3):289-297
In this study, the Box-Wilson statistical experimental design method was employed to evaluate the effects of important variables such as bridging liquid (oil) concentration, salt (CaCl2·2H2O) concentration and stirring speed on the agglomeration of bituminous coal. Response function coefficients were determined by the regression analysis of experimental data and the predictions were found to be in good agreement with the experimental results. The optimum kerosene concentration, CaCl2·2H2O concentration and stirring speed were determined as 30 wt%, 1 M and 1683 rpm, respectively, when considering combustible recovery and ash content.In addition, contact angle and solution surface tension measurements were carried out to evaluate of agglomeration success with the contact angle values and surface tension values. The surface tension of CaCl2 2H2O solutions and the average contact angle increased with increasing CaCl2·2H2O concentration. 相似文献