Bundle event structures: A revised cpo approach

Bundle event structures equipped with a partial order ? have been used to give a true concurrency denotational semantics for LOTOS. This model has also been extended by time and stochastic information. Unfortunately it fails to yield a complete partial order (cpo) as we illustrate by an example.We propose a subset of all bundle event structures such that it forms a cpo. This subset is closed under the usual operators on bundle event structures. And as a consequence these operators are continuous. Therefore, this subset can be used to give a denotational semantics of LOTOS.     

Integrating Process Support and Knowledge Management for Virtual Software Development Teams

In this paper we describe how knowledge management and software process support can be integrated to improve the efficiency of virtual software teams. The approach presented here integrates a process enactment environment with an on-demand knowledge delivery strategy that is based on parameterized information needs models. The parameters in the information needs models are bound at project execution time to values extracted from the process enactment engine. Thus, the approach supports virtual teams by establishing a platform for systematic and task-specific knowledge exchange. The proposed approach is prototypically implemented in the MILOS system, an open source project of the University of Calgary (Canada) and the University of Kaiserslautern (Germany).     

An automated gantry crane as a large workspace robot

In the context of further automation of manufacturing processes, automated transportation of heavy weights using cranes becomes more and more important. Applying the skills of robots to crane automation, a wide market of new applications could be developed. The main idea is to interpret the crane as a large workspace-serving robot. The crane hook represents the effector of the robot. As an example for the effector, an automated storage and retrieval unit for rack operations by a crane with three active auxiliary effector axes has been developed and integrated into the control concept. The control has been realized for a reconstructed 5-t-bridge crane with workspace dimensions of 30 m×8.7 m×7 m.     

15-Methyl-1,2-hexadecanediol,a major constituent of hamster surface wax

Long chain 1,2-alkanediol diesters comprise about 15–20% of the acetone soluble skin surface wax of golden Syrian hamsters. The constituent 1,2-alkanediols, obtained through acidic methanolysis, were fractionated by preparative gas liquid chromatography of their isopropylidene derivatives. The major component (57%) was identified by nuclear magnetic resonance and mass spectrometry as 15-methyl-1,2-hexadecanediol.     

Teilkondensation und nichtadiabate Rektifikation binärer Gemische in Füllkörperrohren

Partial condensation and non-adiabatic rectification of binary mixtures in packed columns. Vertical tube assemblies are preferred for partial condensation of vapour mixtures. The mixture of vapours is fed through the tubes in countercurrent flow to the falling condensate, while coolant flows through the jacket. Only with very large ratios of length L to diameter d of the tubes, i.e. L/d 200, does the separatory effect of partial condensation, owing to rectification mass transfer between the phases, exceed the enrichment effect of partial condensation. Use of ring-shaped packings drastically reduces the characteristic diameter, so that the additional separatory effect occurs at relatively short tube lengths. In the present paper, experimental results concerning the separation efficiency of tubes packed with Raschig rings for non-adiabatic rectification and partial condensation of the “negative” binary mixture n-heptane/benzene are reported and evaluated with the aid of the extended two-film theory. It is found that the resistance to mass transfer averaged over the length of the tube lies entirely on the liquid side on non-adiabatic rectification. Correlation of the Sherwood number of the condensate taken over the length of the tube and the condensate loading clearly shows that the usual calculation of partial condensation with average total mass transfer coefficients does not give physically meaningful results in the case of liquid-side resistance to transport. Calculating procedures which account for the variation of the partial mass transfer coefficients along the tube should lead to improved evaluation or prediction of separation efficiency.     

Pressure dependence of the electric conductance of aqueous solutions of LiCl,KCl and (CH3)4NCl. Correlation of kinetic parameters

The electrical conductivity and the compression of solutions of LiCl, KCl, and (CH₃)₄NCl have been measured as a function of pressure up to 2 kbar at the temperatures 25°, 35° and 45°C in the concentration range 0·1–1 molal. The results are discussed in terms of the transition state theory in relation to kinetic parameters for viscous flow and partial molal volume.