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51.
The classical Coulomb potential and force can be calculated efficiently using fast multi-pole methods. Effective quantum potentials,
however, describe the physics of electron transport in semiconductors more precisely. Such an effective quantum potential
was derived previously for the interaction of an electron with a barrier for use in particle-based Monte Carlo semiconductor
device simulators. The method is based on a perturbation theory around thermodynamic equilibrium and leads to an effective
potential scheme in which the size of the electron depends upon its energy and which is parameter-free. Here we extend the
method to electron-electron interactions and show how the effective quantum potential can be evaluated efficiently in the
context of many-body problems. Finally several examples illustrate how the momentum of the electrons changes the classical
potential. 相似文献
52.
By varying cross-linking intensity, the effect of microbial transglutaminase on acid gels made from casein solution and raw milk was studied. To avoid any impact of heating, N-ethylmaleimide was used for enzyme inactivation after appropriately checking its efficiency. Up to a specific degree of oligomerisation gel stiffness and firmness increased and tan δ, time at gelation onset and syneresis decreased. Above approximately 70% and 25% of cross-linked protein in casein solution and raw milk, respectively, these parameters showed an opposite behaviour, and weak gels with high syneresis were obtained. Substrate differences, such as preferred cross-linking of adjoining κ-caseins on the surface of the micelle enhanced the effect of steric hindrance in raw milk and impaired proper rearrangements upon acidification at a much lower level of oligomerised protein. It is mainly dimeric and trimeric casein that successfully contributed to the enhanced properties of milk protein gels. 相似文献
53.
Sedimentation superimposed on industrial cake filtration leads to longer filtration times and often has a detrimental effect on subsequent process steps such as washing and demoisturing. The influence of sedimentation is seldom recognised in laboratory filtration experiments. Methods are presented for evaluation of pressure filter experiments with superimposed sedimentation which avoid the error made in the usual evaluation methods. For the case of zone sedimentation the article presents a graphical evaluation and a numerical method of modelling permitting scale up to any desired cake height. In superimposed classifying sedimentation simultaneous measurement of filtrate volume and cake height provide information about local variation in filter cake resistance. It is shown for a model system that, owing to sedimentation, the cake resistance shows a minimum at mean cake height and increases rapidly towards greater heights. The local cake resistance corelates with particle size distributions measured for layers of a horizontally cut filter cake. The method of evaluation presented permints determination of the flow resistance of the uppermost layers of a cake and hence estimation of the gas pressure necessary for demoisturing. The profiles of local filter cake resistance show that the relative cake layering is largely independent of the level of suspension filling. A scale-up model is presented for use in those cases where classifying sedimentation cannot be suppressed. 相似文献
54.
55.
Lena Zentner Silke Hügl Clemens Wystup Stefan Griebel Mirna Issa Thomas S. Rau Omid Majdani 《Forschung im Ingenieurwesen》2016,80(1-2):57-69
The cochlear implant, consisting of a compliant electrode carrier (ET) and embedded electrodes with contact wires, is an auditory neuroprosthesis, which is surgically inserted into the inner ear (cochlea) in order to create an auditory impression in the hearing-impaired patients. For simplification of the insertion, a fluidically actuated electrode carrier with a changeable curvature is presented. The deformation of the ET is specifically manipulated by applying pressure to its interior and also by a non-stretchable thin fibre or stripe embedded in its wall. An analytical examination of scaling properties allows to use scaled structures for models and measurements. In order to determine the geometry of the ET, a model-based synthesis – FE method combined with analytical modelling – is carried out. The synthesis resulted in a conical shape of the ET with a cylindrical cavity closed at one end and a fiber running parallel to the cavity. Experimental studies on a measuring geometry show a maximum deviation of 0,6 bar at a maximum internal pressure of 6 bar. The investigations show that the proposed synthesis method is suitable for the development of surgical instruments with adjustable curvature. 相似文献
56.
57.
A Schellart R Veldkamp M Klootwijk F Clemens S Tait R Ashley C Howes 《Water science and technology》2005,52(3):137-146
A greater understanding of the erosion behaviour of sewer sediments is necessary in order to reliably estimate the amount and nature of the sewer sediments released from deposits in sewers and transported either to waste water treatment plants or discharged into the environment. Research has indicated that microbial activity in sediment can influence the physical release of sediment from in-pipe deposits. This paper reports on a series of erosion tests in which sewer sediments from different sewer networks are kept under different environmental conditions and their resistance to erosion is examined. The erosion tests are carried out under aerobic and anaerobic conditions and two temperatures, one representing ambient sewer temperatures and a lower temperature that significantly suppresses bacterial activity. 相似文献
58.
Jason Byrne Alison Cook Jim Walmsley Bambang Hari Wibisono Justin Clemens Ispurwono Soemarno Bruce Moon 《Urban Policy and Research》2001,19(2):258-276
Australian Urban Planning: New Challenges, New Agendas. Brendan Gleeson and Nicholas Low. Allen & Unwin, Sydney, 2000. ISBN 1865082384 (paperback). 273 pp.; bibliography and index. RRP $35.00.
Australian Urban Planning: New Challenges, New Agendas. Review 2.
Equity, Environment, Efficiency: Ethics and Economics in Urban Australia. Patrick Troy (ed.). Melbourne University Press, Melbourne, 2000. ISBN 0522848923 (paperback). 255pp.; bibliography and index. RRP $43.95.
Asian New Urbanism. William S. W. Lim. Select Books, Singapore, 1998. ISBN 9814022012. 250 pp.. RRP $52.00.
Rethinking Australian Citizenship. Wayne Hudson and John Kane (eds). Cambridge University Press, Cambridge, 2000. ISBN 052159670 (paperback), 052159337 9 (hardback). 274pp.; bibliography and index. RRP $34.95 (paperback), $90.00 (hardback).
Community Participation Methods in Design and Planning. Henry Sanoff. John Wiley, New York, 2000. ISBN 0471355453. 306 pp.; bibliography, additional readings and index. RRP $114.95.
Global Spin: The Corporate Assault on Environmentalism. Sharon Beder. Scribe, Melbourne, rev. edn, 2000. ISBN 090801144 (paperback). 336 pp; bibliography and index. RRP $29.95. 相似文献
Australian Urban Planning: New Challenges, New Agendas. Review 2.
Equity, Environment, Efficiency: Ethics and Economics in Urban Australia. Patrick Troy (ed.). Melbourne University Press, Melbourne, 2000. ISBN 0522848923 (paperback). 255pp.; bibliography and index. RRP $43.95.
Asian New Urbanism. William S. W. Lim. Select Books, Singapore, 1998. ISBN 9814022012. 250 pp.. RRP $52.00.
Rethinking Australian Citizenship. Wayne Hudson and John Kane (eds). Cambridge University Press, Cambridge, 2000. ISBN 052159670 (paperback), 052159337 9 (hardback). 274pp.; bibliography and index. RRP $34.95 (paperback), $90.00 (hardback).
Community Participation Methods in Design and Planning. Henry Sanoff. John Wiley, New York, 2000. ISBN 0471355453. 306 pp.; bibliography, additional readings and index. RRP $114.95.
Global Spin: The Corporate Assault on Environmentalism. Sharon Beder. Scribe, Melbourne, rev. edn, 2000. ISBN 090801144 (paperback). 336 pp; bibliography and index. RRP $29.95. 相似文献
59.
60.
D. F. Clemens B. M. Whitehurst G. B. Whitehurst 《Nutrient Cycling in Agroecosystems》1990,25(2):127-131
Within the past 20–25 years it has been recognized that many of the micronutrient requirements of plants could be supplied by complexes containing chelated metals. These chelates find uses in a wide variety of agricultural crops such as: corn, bush beans, cucumbers and citrus groves. Applications vary from fertilizer additives and seed dressing to foliar sprays and hydroponics. The chelates themselves have chemical structures that seem to be limited only by the chemists imagination. The critical factors for the use of any of these chelates is the stability constant and the cost to prepare a pound of chelated metal such as iron or zinc. A comparison of costs for a few of the more common chelates indicates a need for agricultural studies on the results of using glucoheptonates for supplying micronutrients. 相似文献