摘要:

A centrifugal sedimentation method (CSM) is proposed for the assessment of deformability of red blood cells. The method is based on the premise that a red blood cell (RBC) should deform in a centrifugal field due to the variation of the centrifugal acceleration with the distance from the center of rotation. This change in shape of the RBC leads to a change in the rate of sedimentation in the centrifugal field. The rate of sedimentation, which serves as a measure of deformability, is characterized by an apparent sedimentation coefficient (ASC) and its normalized value (NASC), which is calculated by comparison with a control group of normal RBCs. It has been shown that the NASC is sensitive to the speed of rotation, to treatments with glutaraldehyde, diamide, or chlorpromazine, to heat treatment and to osmotic pressure variations.

ISSN:0098-6445    

DOI:10.1080/00986449608936552

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A method for superhigh compression of a gas bubble in a liquid due to forced non-linear, non-periodic resonance oscillations with moderate to small amplitudes of forcing pressure is proposed and analyzed. The key feature of the method is the coordination of the liquid pressure change with the change of bubble volume. The corresponding regime of forced oscillations is called the “basketball dribbling regime”. Analytical solutions describing the process are obtained.

ISSN:0098-6445    

DOI:10.1080/00986449608936553

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

We developed the purification method to produce ultra-pure succinonitrile by multiple countercurrent distillations. The distillation column used was 25 mm in diameter and 110 cm in the packed height with Heli-Pak® packing (0·05” × 0·10” × 0·10”, packing factor+ 960). Typical operational conditions of each stage are as follows: condenser temperature 65 °C, reboiler temperature 160 °C, head pressure 50 m Torr or below, and reflux ratio of 60:1. As the number of distillation stages increases, the maximum temperature of the freezing curve increases and the freezing curves become flat. Triple point of our sample, which is obtained after eight distillation stages, is not appreciably different from that of a standard NIST specimen. The purity of the SCN prepared in our experiments is estimated at 99·99992% which corresponds to a melting range (T1, – Ts) of 1·2 mK. To ensure the purity of our purified SCN for the purpose of crystal growth, the growth rate and the tip radius of dendrite were measured at various supercooling. It was found that there was no discrepancy in data between ours and Glicksman's within measurement errors. We could prepare ultra-pure succinonitrile at a rate about 1500 g within a week in our distillation column, which is much more faster compared to that obtained by zone refining. Furthermore, since the scale-up method of distillation unit is well developed, it is possible that a much larger amount of ultra pure SCN can be produced in a short time.

ISSN:0098-6445    

DOI:10.1080/00986449608936554

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A multicomponent transport model is presented to describe the rejection components of electrolyte systems by cellulose acetate reverse osmosis membranes. Comparison of the model with the experimental results obtained with NaCl-CaCl2-H2O solutions shows good agreement. It was observed that the presence of CaCl2can reduce drastically the rejection of NaCl in this multicomponent system and even cause ‘negative rejection’ in certain cases. The results of this study will be helpful in better understanding, predicting and controlling the operation of reverse osmosis desalination plants that process multicomponent feeds where interactions among the electrolytes present can affect the performance of the membranes used

ISSN:0098-6445    

DOI:10.1080/00986449608936555

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Aluminum nitride based materials were synthesized by combustion of aluminum powder in air. When aluminum nitride powder is used as a diluent, mostly aluminum nitride product with small amount of alumina was obtained. For reactant mixtures consisting of 33 wt% of aluminum and 67 w% of alumina, materials with a high content of aluminum oxynitride (AION) were formed. Synthesized aluminum nitride based powders with and without in-situ added sintering aids were characterized and tested for their sintering ability. Densification characteristics of combustion synthesized powders by pressureless sintering in nitrogen atmosphere are also reported.

ISSN:0098-6445    

DOI:10.1080/00986449608936556

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

In this paper, we provide exact analytical solutions for a new method of constant molar flow of pure gas into a reservoir containing solid adsorbents having a bidispersed structure, such as zeolite, activated carbon and alumina. Depending on the diffusion mechanism, two models are proposed under the isothermal conditions and linear isotherm. One is applicable to zeolite, and the other for alumina and activated carbon. The solutions of these two models are in the form of an infinite series, and its eigenvalues are determined from a transcendental equation. This transcendental equation is such that the eigenvalues are lumped into infinite but countable groups, and in each group there are infinite but countable eigenvalues. The dominant eigenvalues are generally the first ten to thirty eigenvalues (depending on the value of time at which the series is evaluated) in each group. The pressure response of the reservoir is a function of time as the result of the introduction of adsorbate into the reservoir, and as time is sufficiently large it asymptotes to a straight line, of which the slope is a function of the equilibrium parameters only and the intercept is found to be an explicit function of the equilibrium parameters as well as the diffusivities in the macropore and micropore.

ISSN:0098-6445    

DOI:10.1080/00986449608936557

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The problem of electromagnetic heating of a small sphere is solved for transient and steady state conditions, taking into account the highly nonuniform energy absorption determined from Mie theory. The effects of conduction, convection and radiation boundary conditions are explored to determine the conditions under which radiant energy transfer becomes the dominant mechanism of heat loss and to predict laser intensities required to heat a particle to a specified mean temperature.

ISSN:0098-6445    

DOI:10.1080/00986449608936558

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Diffusional effects in reactions involving macromolecular substrates and reactants in heterogeneous media lead to unique features. We report investigations on the hydrolysis of 2-hydroxy ethyl methacrylate copolymers catalyzed by imidazole and poly (W-vinyl imidazole) selected as an enzyme mimicing polymer. This process has been mathematically modelled, and the predictions compared with experimental findings. The model framework is general for diffusion-reaction problems of this class. The work has also pragmatic relevance in the design of drug delivery systems, since the reaction takes place in pH ranges of physiological significance.

ISSN:0098-6445    

DOI:10.1080/00986449608936559

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The delaminated Fe203-pillared clay shows high activities for selective catalytic reduction (SCR) of NO by NH2. Temperature program desorption (TPD) studies show that large amounts of NO., are adsorbed on the pillared clay catalyst at the SCR reaction temperatures (i.e. near 400°C). This result indicates that a Langmuir-Hinshelwood type mechanism (for reaction between chemisorbed NO, and NH, on the surface to form N2) is operative for the pillared clay catalyst, which is in contrast to the SCR reaction on the commercial vanadia-based catalysts. The SCR activities for the delaminated Fe203-pillared clay catalyst are higher than that of a commercial-type V2O5+ WO3/TiO2catalyst under SO2+ H20 free conditions, but became lower in the presence of SO2+l H20. However, when promoted by doping 1–3% Cr203, the pillared clay catalyst exhibits higher SCR activities than the commercial-type catalyst in the presence of S02+ H2O at all practical SCR reaction temperatures

ISSN:0098-6445    

DOI:10.1080/00986449608936560

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Several elementary heat conduction examples are given demonstrating the need to employ a fictitious initial condition in place of the true initial condition in homogenized, effective medium descriptions of transient thermal phenomena for systems where the boundary conditions are such that the heat originally present in the system is not conserved. The need arises as a consequence of the spatial inhomogeneity of the local rate of heat transfer towards the boundaries during the period existing prior to that at which the effective medium description of the system becomes a faithful macroscale model of the transient micro-scale phenomena. While the illustrations are confined for simplicity to pure conduction problems, the need to use fictitious initial conditions extends to broader classes of problems, including those for which forced convection plays a major role in the thermal transport process.

ISSN:0098-6445    

DOI:10.1080/00986449608936561

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor