On the Minimum Common Supergraph of Two Graphs

The minimum common supergraph of two graphs, g₁ and g₂, is defined as the smallest graph that includes, as subgraphs, both g₁ and g₂. It is shown that minimum common supergraph computation can be solved by means of maximum common subgraph computation. For the latter problem, algorithms are known from the literature. It will also be shown that for a certain class of cost functions, the concept of graph edit distance is closely related with the minimum common supergraph.     

Über Zeitkonstanten von Kondensatoren

Zusammenfassung Bei hinreichend langer Trocknung und Bernsteinisolation lassen sich mit Luftkondensatoren Zeitkonstanten erreichen, die in der Größenordnung 10⁷ s bzw. 10³ s/pF liegen. Die physikalischen Ursachen der Entladung werden näher untersucht. Praktisch erfolgt die Entladung nur über die Bernsteinisolation; die Leitfähigkeit der Luft ist zu vernachlässigen. Maßgebend für die Entladung ist das Verhältnis Volumen zur Kapazität. Hohe Zeitkonstanten lassen sich erreichen, wenn das Verhältnis Volumen zur Kapazität klein ist. Kondensatoren mit sehr hohen Zeitkonstanten finden ihre Anwendung, z. B. wenn ein aufgeladener Kondensator als Vergleichsspannungsquelle dienen soll, bei der elektrischen Kurzzeitmèssung als Zeittransformator oder zur Messung sehr hoher Widerstände von der Größenordnung 10¹⁰ bis 10¹⁵ nach dem Kondensatorentladungsverfahren. Über eine weitere Anwendung wird demnächst berichtet werden.Die vorliegende Untersuchung wurde von Herrn Prof. Dr.-Ing. E. h. Dr.-Ing. W. Rogowski angeregt, dem ich für seine vielseitige Unterstützung zu großem Dank verpflichtet bin. Der Deutschen Forschungsgemeinschaft danke ich für die Mittel zur Durchführung der Arbeit.     

Optimisation models to enhance resilience in evacuation planning

We argue that the concepts of resilience in engineering science and robustness in mathematical optimisation are strongly related. Using evacuation planning as an example application, we demonstrate optimisation techniques to improve solution resilience. These include a direct modelling of the uncertainty for stochastic or robust optimisation as well as taking multiple objective functions into account.     

Integrated synthesis and extraction of short‐chain fatty acid esters by supercritical carbon dioxide

We developed an efficient, integrated reaction‐extraction process for the production of short‐chain fatty acid ethyl esters (FAEE) from milk fat, using carbon dioxide as the only processing solvent. FAEE were synthesized using a short‐chain fatty acid selective lipase. The expansion of the liquid mixture of reactants by dense carbon dioxide enhanced the apparent lipase selectivity. In situ extraction of FAEE by a continuous flow of supercritical carbon dioxide proved to increase the lipase production rate. When the integrated process was operated with alternated periods of synthesis and product removal, the overall selectivity for short‐chain FAEE increased as well, as a result of the combination of the selectivities of lipase and extraction solvent. A two‐fold increase of the lipase productivity was achieved at these conditions, compared to a single batch reaction. The developed process enables the synthesis and isolation of high‐value fatty acid derivatives from a natural source such as milk fat. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

现代过滤器清洁技术必须增加效益和避免环境问题

介绍了Schwing公司用于聚合物纺丝过滤系统组件的清洁工艺和设备,技术要点是采用水解或热解原理,具有增加效益和避免环境问题的优点。     

Prof. Dr. Dr. h.c. Karl Kratzl Emeritus

Ohne Zusammenfassung     

Regulation of calf renal 25-hydroxyvitamin D-hydroxylase activities by calcium-regulating hormones

Parathyroid hormone and 1,25-dihydroxyvitamin D3 had opposite effects on calf renal 25-hydroxyvitamin D3 24-, 23-, and 1 alpha-hydroxylase activities. Parathyroid hormone administration increased renal 25-hydroxyvitamin D3-1 alpha-hydroxylase activity 7-fold while 25-hydroxyvitamin D3-23- and 24-hydroxylase activities were essentially the same as controls. Administration of 1,25-dihydroxyvitamin D3 increased 25-hydroxyvitamin D3-23-hydroxylase and 24-hydroxylase activities 4-fold and decreased 25-hydroxyvitamin D3-1 alpha-hydroxylase activity to undetectable concentrations. Vitamin D deficiency increased 25-hydroxyvitamin D3-1 alpha -hydroxylase activity 13-fold, and 25-hydroxyvitamin D3-23-hydroxylase and 24-hydroxylase activities were undetectable. These results confirm previous reports with regard to control of renal 25-hydroxyvitamin D3-24-hydroxylase and 1 alpha -hydroxylase in other species and represent new findings relative to the control of 25-hydroxyvitamin D3-23-hydroxylase. Plasma P was lower and 1,25-dihydroxyvitamin D3 higher in calves treated with parathyroid hormone, and Ca and 1,25-dihydroxyvitamin D3 were lower in the vitamin D-deficient calves. 1,25-Dihydroxyvitamin D3-treated calves had higher plasma P and lower Mg than controls. Further studies using this calf model should lead to better understanding of Ca-regulating hormones control of vitamin D metabolism.     

LIQUID-LIQUID EXTRACTION STUDIES OF METAL IONS WITH DIAZACROWN AND STRUCTURE ANALOGOUS OPEN-CHAIN COMPOUNOS

1,10-diaze [8]crown-6, their N,N'-dibutyl- and dioctyl-substituted derivatives and the structure analogous open-chein tetreoxedieza slkanee have been synthesized in order to examine the extraction properties for Na⁺, K⁺, Sr²⁺ and Hg²⁺. It wes found, that the extraction of strontium, potassium and sodium picratee with azacrown compounds ie much higher than that with open-chein oxaaze alkanes. 1,10-diaze [18] erown-6 has a good selectivity for the extraction of Sr²⁺ over K⁺ and Na in alkaline solution. In the case of Sr²⁺ the diffarencea between tha various azacrown compounds are email, whereea in the caee of K⁺ and Na the substituted derivativee are better extractante. Theserssulte correspond qualitativsly with tha order of stebility conetantB in protic solvsnts. The extrectebility of N,N'-dioctyl-l, 10-dieze[18]crown-6 for HgCl₂ is very high. Contrerv to the order of stability conetants the uneubetituted conpound do not extract mercury under the choeen experimental condition*. The extraction power of open-chain conpounde ie aleo high and strong Influenced by the alkyl eubatltuente at the nitrogen donor stons,     

Generalized sparse MRF appearance models

Image segmentation or registration approaches that rely on a local search paradigm (e.g, Active Appearance Models, Active Contours) require an initialization that provides for considerable overlap or a coarse localization of the object to be segmented or localized. In this paper we propose an approach that does not need such an initialization, but localizes anatomical structures in a global manner by formulating the localization task as the solution of a Markov Random Field (MRF).     

Measurement and Calculation of the Absolute Thermoelectric Power of Rhodium and Iridium

The thermoelectric power of Rh and Ir was redetermined between 100 K and 1400 K. It varies almost linearly from +1.7 μV K⁻¹ to −3.8 μV K⁻¹ for Rh and from +1.5 μV K⁻¹ to −2.2 μV K⁻¹ for Ir. The diffusive part of the thermopower could be calculated from the density of states. It is approximately equal to the temperature dependence of the electrochemical potential of the electrons divided by the electronic charge. This is attributed to the approximate establishment of local equilibrium between electrons and lattice atoms above 400 K—a condition not fulfilled in the phonon-drag regime below 300 K.