Modeling and experimental validation of pressure drop for pneumatic plug conveying

This paper indicates that a variety of models exist to calculate the pressure drop of pneumatic plug conveying. Unfortunately these models are limited in their flexibility and calculate pressure drop only for two extremes, the active and passive case of bulk solid. Until now the stress state within the plug cannot be determined. Therefore a sensor was built to detect wall shear stress, normal stress and the stress state along a moving plug. Beginning with vertical pneumatic plug conveying, the previous models were verified and modified to get new perceptions about formation, stability and pressure drop of plugs.The DFG (German Research Community) is gratefully appreciated for the financial support to this work.Received October 2003     

Modeling of striplines between a power and a ground plane

In this paper, a stripline model is presented for coupled signal lines routed between a power and a ground plane based on multiconductor transmission line (MTL) theory. Through a suitable diagonalization of the MTL equations for striplines, the transverse electromagnetic (TEM) parallel-plate mode is decoupled from the stripline mode. In this way, stripline models that are obtained assuming ideal planes at ground potential can be extended to take into account the nonideal behavior of the planes. The presented model is applied to represent mode conversion due to vias, holes in the reference planes, and terminations of the stripline. Influence of inhomogeneous media is discussed.     

Computer evidence: A forensic investigations handbook

It is never easy to decide when to publish a book. Against the undoubted benefits of scoring a ‘first’ in a new subject are the undoubted hazards of hitting while the topic is too immature and fast-evolving to be safely encapsulated within a permanent binding.     

运用一步化体外转录—翻译系统筛查基因突变的新技术

报道了一种筛查基因突变的新技术－ＰＣＲ结合一步化体外转转录－翻译系统。该技术包括：（１）ＰＣＲ扩增靶ＤＮＡ片段，并使ＤＮＡ产物的一端或两端带上Ｔ７Ｔ１序列；（Ｔ１：翻译起始信号，ＣＣＡ ＣＣＡ ＴＧ）；（２）以核的为模板，利用一步化体外转录－翻译系统合成相应肽链；（３）用ＳＤＳ－ＰＡＧＥ及高分辨ｐＨ梯度ＰＡＧＥ（聚丙烯酰胺凝胶电泳）分离分析多肽产物，通过异常电泳图谱而发现基因突变，本文以已知突变的     

Bibliometric analysis and private research funding

Summary The year 2002 brought a successive funding change-over from until now institutional to programme oriented funding (POF) in the Helmholtz Association of German Research Centres (HGF). This way the 15 German research centres now have to generate their means successively from programmes of the research fields of the HGF (see: www.helmholtz.de) by competing with each other. This nucleus of the reform of the Association is being implemented based upon the opinion of international experts. In this context the evaluation of publications of individual research centres, resp. research groups will be playing an ever increasing part. This lecture will inform about the reformed, partially formalized system and first experiences therewith at the time of the first evaluations.     

Database of mutations in the p53 and APC tumor suppressor genes designed to facilitate molecular epidemiological analyses

Germline and somatic mutations in the p53 and APC genes contribute to neoplasia. The patterns of these and other acquired mutations in cancers reflect environmental mutagens and endogenous factors that contribute to carcinogenesis. Herein, we describe a database of almost 2,300 mutations in the p53 and APC genes published until September 1, 1993. In addition to cataloging the mutations, multiple fields of information have been added to facilitate future molecular epidemiological analyses of human cancer. The accuracy of the database has been checked by the present authors and, by soliciting feedback from the original corresponding authors. The strengths and limitations of the primary literature are discussed.     

Possibilities to improve the short-term dosing constancy of volumetric feeders

For some applications, e.g. processes with stoichiometric reactions or the mixing of powders in a static mixer, a high short-term dosing constancy is necessary. For the dosing of calcium carbonate with a median diameter of 2 μm, it is shown that the pulsation of a volumetric feeder can be reduced tremendously by the use of different attachments for the dosing tube. The best results were obtained with a self-developed rotating star attachment. The quantitative assessment of the efficiency was performed both in the time domain with the standard deviation and in the frequency domain with the fast Fourier transformation.