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Tsinghua Science and Technology 2005年第5期10卷 523-528页

作者：任钟旗费维扬 hans-joerg bart State Key Laboratory of Solvent Extraction Department of Chemical Engineering Tsinghua University Beijing 100084 China Institute of Chemical Engineering University of Kaiserslautern Kaiserslautern 67653 Germany

The Taylor dispersion method was used to measure diffusion coefficients of three-component liquid systems. An improved constrained nonlinear least-square method was used to evaluate the ternary diffusion coefficients directly by fitting the mathematical solutions of the dispersion equation to eluted solute peaks detected using a differential refractometer. Diffusion coefficients of the three-component system of acetone-benzene-CCl4, determined at 25℃, were used to test the procedure. The measured diffusion coefficients were compared with values obtained by optical interferometry and the diaphragm cell method. Ternary diffusion coefficients are also determinated for solutions of 1-hexanol-hexane-toluene and 1-propanol- water-ethylene glycol at 25℃, with an accuracy of approximately 0.05 m^2·s^- 1.

关键词： Taylor dispersion method ternary diffusion coefficient constrained nonlinear least-squared method Fick law

Evaluation of Hydroabrasion in a Slurry Tank

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Journal of Energy and Power Engineering 2013年第12期7卷 2273-2284页

作者： Mehdi Azimian hans-joerg bart Chair of Separation Science and Technology Mechanical and Process Engineering Faculty University of KaiserslauternKaiserslautern D-67663 Germany

A slurry erosion tank test rig was designed and built to investigate the erosion rates of different materials and effects of the influencing parameters on material loss and erosion profiles. A CFD （computational fluid dynamics） tool is applied to study the flow impact velocity, solid concentration and particle size effects on the erosion rate of sample plates in the liquid-solid mixture in a cylindrical tank. The MRF （multiple reference frames） method is applied to model the rotating parts inside the tank. The flow behavior and liquid-solid interactions in the slurry tank test rig are simulated and the results are validated with the experimental data. It was approved that changing the height and diameter of each rotating zone （MRF zones） have a negligible effect on simulation results. It was observed that the erosion mass losses are increasing with increase in flow velocity and sand concentration. Both variations can be predicted with a logarithmic dependence of mass loss to rotational velocity and sand concentration. The increase in erosion rate by increase in particle size was also observed for three various particle size distributions.

关键词： CFD liquid-solid mixture slurry tank erosion rate.

Swelling Kinetics Associated with Diffusion of Poly （N-isopropylacrylamide） Hydrogel

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材料科学与工程（中英文B版） 2011年第3期1卷 247-258页

作者： Naddaf Aisha Ahmad hans-joerg bart Chair of Separation Science and Technology Kaiserslautern University Kaiserslautern 67653 Germany

Numerical analysis of hydroabrasion in a hydrocyclone

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Petroleum Science 2016年第2期13卷 304-319页

作者： Mehdi Azimian hans-Jorg bart Department of Mechanical and Process Engineering University of Kaiserslautern 67663 Kaiserslautern Germany

The velocity profiles and separation efficiency curves of a hydrocyclone were predicted by an Euler-Euler approach using a computational fluid dynamics tool ANSYS-CFX 14.5. The Euler-Euler approach is capable of considering the particle-particle interactions and is appropriate for highly laden liquid-solid mixtures. Pre- dicted results were compared and validated with experi- mental results and showed a considerably good agreement. An increase in the particle cut size with increasing solid concentration of the inlet mixture flow was observed and discussed. In addition to this, the erosion on hydrocyclone walls constructed from stainless steel 410, eroded by sand particles （mainly SiOz）, was predicted with the Euler-La- grange approach. In this approach, the abrasive solid particles were traced in a Lagrangian reference frame as discrete particles. The increases in the input flow velocity, solid concentration, and the particle size have increased the erosion at the upper part of the cylindrical body of the hydrocyclone, where the tangential inlet flow enters the hydrocyclone. The erosion density in the area between the cylindrical to conical body area, in comparison to other parts of the hydrocyclone, also increased considerably. Moreover, it was observed that an increase in the particle shape factor from 0.1 to 1.0 leads to a decrease of almost 70 % in the average erosion density of the hydrocyclone wall surfaces.

关键词： Hydrocyclone Computational fluiddynamicS (CFD) Separation efficiency - Erosion rateErosion impact parameters

From Single Droplet to Column Design

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Tsinghua Science and Technology 2006年第2期11卷 212-216页

作者： hans-Jrg bart Institute of Thermal Process Engineering TU Kaiserslautern D-67653 Kaiserslautern Germany

The technique state to design counter-current extraction columns is based on the performance of pilot plant experiments. The modelling is then either with the equilibrium or dispersion model, whereas in the latter the dispersion coefficient accounts for all hydrodynamic non-idealities. A new approach uses single droplet experiments to obtain the basic laws and functions governing droplet breakage, coalescence, relative velocity, and axial dispersion when using droplet populance balance models （DPBM）. The hydrodynamics simulation results show that the mean Sauter diameter, hold-up, and concentration profiles could be well predicted, which promotes the use of DPBM models for further applications in industrial scale.

关键词： single droplet column design countercurrent extraction droplet populance balance model

CFD aided investigation of single droplet coalescence

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Chinese Journal of Chemical Engineering 2016年第2期24卷 249-252页

作者： Felix Gebauer Mark W.Hlawitschka hans-Jorg bart Chair of Separation Science and Technology University of KaiserslauternKaiserslautern 67653Germany Center for Computational and Mathematical Modelling(CIVY) University of KaiserslauternKaisersloutern 67653Germany

This article describes the development of a coalescence model using various CFD work packages,and is validated using as toluene water model *** studies were performed to describe droplet interactions in liquid–liquid test *** models use adjustable parameters to describe these *** research in the past decades led to different correlations to model coalescence and breakage depending on the chemical system and the apparatus *** the complexity of droplet coalescence requires a detailed investigation of local phenomena during the droplet *** fluid dynamics(CFD) studies of single droplet interactions were performed and validated with experimental results to improve the understanding of the local hydrodynamics and film drainage during *** CFD simulations were performed for the interaction of two differently sized droplets at industrial relevant impact *** experimental verification and validation of the numerical results were done with standardized high-speed imaging studies by using a special test cell with a pendant and a free rising *** experimental based algorithm was implemented in the open source code OpenF OAM to account for the contact time and the dimple *** standard European Federation of Chemical Engineering(EFCE) test system toluene/water was used for the numerical studies and the experimental investigations as *** results of the CFD simulations are in good accordance with the observed coalescence behavior in the experimental *** addition,a detailed description of local phenomena,like film rupture,velocity gradients,pressures and micro-droplet entrainment could be obtained.

关键词： CFD Parameter estimation Coalescence Film drainage

Body Building on Diamonds

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Journal of Bionic Engineering 2009年第1期6卷 14-17页

作者： Andrei P. Sommer Tim Scharnweber hans-joerg Fecht Institute of Micro and Nanomaterials University of UlmUlm 89081Germany Institute for Biological Interfaces Research Center KarlsruheKarlsruhe 76021Germany Institute for Nanotechnology Research Center Karlsruhe Karlsruhe 76021Germany

Whereas conservative therapies aim to stall the advance of disease,regenerative medicine strives to reverse *** capacity of most tissues to regenerate derives from stem cells,but there are a number of barriers which have to be circumvented before it will be possible to use stem-cell-based *** therapies,however,are expected to improve human health enormously, and knowledge gained from studying stem cells in culture and in model organisms is now laying the groundwork for a new era of regenerative *** of the most prominent methods to study stem cell differentiation is to let them to form embryoid *** favourable conditions any stem cell line will form embryoid ***,the mechanism of the formation of embryoid bodies is not very well understood,and to produce them in the laboratory is in no way trivial-an important technical barrier in stem cell ***,the embryoid body cultivation step has been successfully circumvented for the derivation of osteogenic cultures of embryonic stem *** we report on a simple and reusable system to cultivate embryoid bodies in extremely short *** method is inspired by the principles that lead to the establishment of the biomimetic triangle.

关键词： biomimetic triangle stem cells embryoid bodies nanobionics nanocrystalline diamond

The Top of the Biomimetic Triangle

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Journal of Bionic Engineering 2008年第2期5卷 91-94页

作者： Andrei P. Sommer Dan Zhu Matthias Wiora hans-joerg Fecht Institute of Micro and Nanomaterials University of Ulm Ulm 89081 Germany Institute for Nanotechnology Forschungszentrum Karlsruhe Karlsruhe 76021 Germany

There is increasing observational evidence indicating that crystalline interfacial water layers play a central role in evolution and biology. For instance in cellular recognition processes, in particular during first contact events, where cells decide upon survival or entering apoptosis. Understanding water layers is thus crucial in biomedical engineering, specifically in the design of biomaterials inspired by biomimetic principles. Whereas there is ample experimental evidence for crystalline interfacial water layers on surfaces in air, their subaquatic presence could not be verified directly, so far. Analysing a polarity dependent asym- metry in the surface conductivity on hydrogenated nanocrystalline diamond, we show that crystalline interfacial water layers persist subaquatically. Nanoscopic interfacial water layers with an order different from that of bulk water have been identified at room temperature on both hydrophilic and hydrophobic model surfaces - in air and subaquatically. Their generalization and systematic inclusion into the catalogue of physical and chemical determinants of biocompatibility complete the biomimetic triangle.

关键词： biomimetic triangle crystalline interfacial water layers nanobionics diamond

It is Time for a Change： oPetri Dishes Weaken Cells

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Journal of Bionic Engineering 2012年第3期9卷 353-357页

作者： Andrei P. Sommer Mike Kh. Haddad hans-joerg Fecht Institute of Micro and Nanomaterials University of Ulm 89081 Ulm Germany Institute for Nanotechnology Karlsruhe Institute for Technology 76344 Eggenstein-Leopoldshafen Germany

We wish to draw the attention to a potential deficiency in the biocompatibility of polystyrene cell culture dishes which is caused by a softening of the material under relevant culture conditions. The finding confirms the central hypothesis of our previous model study. In it we assumed a local increase in pH at the interface between the hydrophilic polymer and liquid. The finding is of considerable biological interest. Polystyrene tissue culture dishes are now in use for 50 years. To the best of our knowledge their biocompatibility has never been challenged. Here we report the first experimental proof that exposure to water softens the surface of polystyrene Petri dishes. We expect that our results will stimulate the development of a new generation of cell culture devices, including Petri dishes and culture flasks, and the establishment of improved biomimetic settings for tissue engineering and stem cell research. New non-swelling biomaterials or nanocoatings designed to reduce the swelling of polymer ct, lture dishes could improve cell performance. The need for further study is clear.

关键词： Petri dish polystyrene biomimetic triangle nanoindentation stem cells diamond

Phosphate removal from wastewater by model-La(Ⅲ)zeolite adsorbents

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Journal of Environmental Sciences 2008年第6期20卷 670-674页

作者： NING Ping bart hans-Jorg LI Bing LU Xiwu ZHANG Yong Department of Environmental Science and Engineering Kunming University of Science and Technology Kunming 650093 China Lehrsmhl für Thermische Verfahrenstechnik TU Kaiserslautern D-67653 Kaiserslautern Germany Department of Environmental Engineering Southeast University Nanjing 210096 China

Phosphorus is one of the primary nutrients which leads to eutrophication and accelerates aging process in enclosed water bodies. Because of the poor phosphorus selectivity of other adsorbents, the novel La（Ⅲ）-modified zeolite adsorbent （LZA） was prepared by modifying 90 nm zeolite with lanthanide to selectively remove phosphate in the presence of various omnipresent anions, such as sulfates, bicarbonates, and chlorides. Through batch and fixed bed operation, the following optimum conditions were obtained： concentration of lanthanum chloride solution 0.05 mol/L; solid/liquor ratio 1/25; pH 10; calcination temperature 550℃; time 1 h. The value of the Freundlich model constants Kf and 1/n were found to be 16.76 mg/L and 0.2209, respectively. In addition, when calculated at pH 6.0, distribution coefficient KD could be as high as 36.6. Furthermore, in the alkaline pH range, solution of 0.8 mol/L NaCl was used to regenerate the saturated LZA, which could reach the high regeneration efficiency as high as 100%. Because of the good selectivity and regenerability of LZA, it might serve as a potential way for advanced phosphate removal from the sewage containing other anions.

关键词： phosphate adsorption zeolite regeneration distribution coefficient