Dimension reduction of bivariate population balances using the quadrature method of moments

Crystallization models with direction-dependent growth rates give rise to multi-dimensional population balance equations (PBE) that require a high computational cost. We propose a model reduction based on the quadrature method of moments (QMOM). Using this method a two-dimensional population balance is reduced to a system of one-dimensional advection equations. Despite the dimension reduction the method keeps important volume dependent information of the crystal size distribution (CSD). It returns the crystal volume distribution as well as other volume dependent moments of the two-dimensional CSD. The method is applied to a model problem with direction-dependent growth of barium sulphate crystals, and shows good performance and convergence in these examples. We also compare it on numerical examples to another model reduction using a normal distribution ansatz approach. We can show that our method still gives satisfactory results where the other approach is not suitable.     

Minimum surcharge load of URM walls under flexure and axial force / Mindestauflast bei Biegung mit Normalkraft

This paper suggests a detailed parametric study, which has been drawn up in connection with the question of the necessity of verification of masonry wall by a minimum vertical load subject to bending and normal force by the author and his team [7]. It assumes the actual eccentricities from supporting due floors and takes into account the second order theory in middle of wall according to DIN EN 1996‐1‐1 or the German NA. In some cases, the model is derived for very high wind loads to its limits. Using the arch model which is introduced in DIN EN 1996‐1‐1 and may be applied by NA, is helpful and effective. This method may provide higher capacity rather than for example, with the bar or plate model. In this article the verification by means of the arch model will be presented and discussed. It is also shown that, forming an arch opposing to the horizontal wind load and low vertical loads may not come to a stability failure.     

Folgen des Globalen Wandels für das Grundwasser in Süddeutschland – Teil 1: Naturräumliche Aspekte

In order to account for complex interactions between humans climate and the water cycle, the research consortium GLOWA-Danube (www.glowa-danube.de) has developed the simulation system DANUBIA which consists of 17 coupled models. DANUBIA was applied to investigate various impacts of global-change between 2011 and 2060 in the Upper Danube Catchment. This article represents part 1 of an article series and describes groundwater and natural aspects of the investigations, while part 2 describes socio-economic aspects (Barthel et al. in Grundwaser 16(4), doi:10.1007/s00767-011-0180-y, 2011). Here we describe concepts of GLOWA-Danube and DANUBIA as well as groundwater-related model components. This leads to selected simulation results for water balance, groundwater quantity and quality. The chosen scenarios show decreasing precipitation, increasing temperatures, and changes in the annual distribution that lead to significant decreases in groundwater recharge. Regional predictions of groundwater quality were difficult to achieve because of complex soil and groundwater processes. However, climatic change will probably have little impact.     

Extending citer analysis to journal impact evaluation

The concept of citer analysis investigated earlier by Ajiferuke and Wolfram (In: B. Larsen, J. Leta (eds.) Proceedings of the 12th international conference of the international society for scientometrics and informetrics (ISSI) pp. 798–808, 2009, Scientometrics 83:623–638, 2010) is extended to journals where different citing units (citers, citing articles, citing journals) are compared with the journal impact factor and each other to determine if differences in ranking arise from different measures. The citer measures for the 31 high impact journals studied from information science and library science are significantly correlated, even more so than the earlier citer analysis findings, indicating that there is a close relationship among the different units of measure. Still, notable differences in rankings for the journals examined were evident for the different measures used, especially from either 5-year impact factor or number of citing articles per publication to the number of citing journals per publication. The journals that are adversely affected seem to be those whose citations are concentrated in a few journals. This informed the need to develop a journal citation concentration index, which can serve as a complementary measure to the existing journal impact indices.     

Fette und Ernährung aus Sicht der DGE

Fat and Nutrition - The Point of View of the DGE Fat is an important energy source because of its high energy density. Moreover fat in food is carrying fat soluble vitamins and essential fatty acids. Fat contributes to the taste of dishes and increases the acceptance of food. Energy density of fat is important for the high energy demand of children and heavy workers. The supply of fat soluble antioxidative vitamins is of increasing importance. The influence of the amount and the quality of fat on lipoproteins in blood and coronary risk as well as epidemiological data on the relation of a high fat intake and the risk of different kinds of cancer are of importance. Fat intake is a critical factor in nutrition and should be intensively monitored with respect to upper and lower limits.