Parameter-study on the influence of steel fibers and coarse aggregate content on the fresh properties of self-compacting concrete

Self-compacting concrete (SCC) offers several economic and technical benefits; the use of steel fibers extends its possibilities. Steel fibers bridge cracks, retard their propagation, and improve several characteristics and properties of the concrete. Fibers are known to significantly affect the workability of concrete. Therefore, an investigation was performed to compare the properties of plain SCC and SCC reinforced with steel fibers. Two mixtures of SCC with different aggregate contents were used as reference. Each of the concretes was tested with four types of steel fibers at different contents in order to answer the question to what extent the workability of SCC is influenced. The slump flow, a fiber funnel and the J-ring test were used to evaluate the material characteristics of the fresh concrete. This paper discusses the suitability of the applied test methods and the effect of the coarse aggregate content, the content and type of steel fibers on the workability of SCC.     

Continuous Model-Driven Engineering

CMDE has been successfully applied in several industrial projects, including telecommunication services, supply-chain management, bioinformatics, logistics, and healthcare. In all these cases, agility at the customer, user, and application level proved key to aligning and linking business and IT. We now expect an additional boost when integrating this approach into a processor project-management environment that oversees development and evolution. This environment will include deadline management and progress reports, automatically informing all relevant parties when certain actions are required, managing different versions and product lines, and automatically steering the build and quality-management process. Perhaps not surprisingly, the development of this management environment proved to be a prime application of CMDE.     

Factorial interlaboratory tests for microbiological measurement methods

This paper presents a validation approach for microbiological methods based on a combination of interlaboratory tests and factorial experiments. It requires not more than 4 participants but is achieving comparable statistical confidence as in method validation studies with 8–12 participants, if properly designed. The approach is illustrated by a comprehensive validation of the Arxula adeninivorans yeast estrogen screen (A-YES) assay for the detection of estrogenic activity in mineral water.     

Accelerated Visualization of Dynamic Molecular Surfaces

Molecular surfaces play an important role in studying the interactions between molecules. Visualizing the dynamic behavior of molecules is particularly interesting to gain insights into a molecular system. Only recently it has become possible to interactively visualize dynamic molecular surfaces using ray casting techniques. In this paper, we show how to further accelerate the construction and the rendering of the solvent excluded surface (SES) and the molecular skin surface (MSS). We propose several improvements to reduce the update times for displaying these molecular surfaces. First, we adopt a parallel approximate Voronoi diagram algorithm to compute the MSS. This accelerates the MSS computation by more than one order of magnitude on a single core. Second, we demonstrate that the contour‐buildup algorithm is ideally suited for computing the SES due to its inherently parallel structure. For both parallel algorithms, we observe good scalability up to 8 cores and, thus, obtain interactive frame rates for molecular dynamics trajectories of up to twenty thousand atoms for the SES and up to a few thousand atoms for the MSS. Third, we reduce the rendering time for the SES using tight‐fitting bounding quadrangles as rasterization primitives. These primitives also accelerate the rendering of the MSS. With these improvements, the interactive visualization of the MSS of dynamic trajectories of a few thousand atoms becomes for the first time possible. Nevertheless, the SES remains a few times faster than the MSS.     

Zutrittskontrolle mit Gesichtserkennung

Firmen&ProdukteDehn Austria

überspannungs-schutz in der Telekommunikation     

Service Engineering: Linking Business and IT

With its strong emphasis on modularization, service-oriented computing radically alters the way business processes are modeled, realized, and maintained. Domain-specific services virtualize complex functions of the underlying business applications so that they can be loosely coupled to form transorganizational processes. This level of abstraction fosters agility and lessens traditional provider dependence. Service-oriented design has long driven the development of the telecommunications infrastructure and applications, especially intelligent network services. Applying the same principles of domain specificity, visualization, loose coupling, and seamless vertical integration to business processes has the potential to lead to a new generation of personalized, secure, and highly available Web services     

Advertising an event

The paper considers a problem of how to minimize advertising costs to sell seats for a particular event, for instance, a sports game, a rock concert or a ballet performance. We take into consideration a word-of-mouth effect, which means that people buying a ticket tell their friends about it, so that advertising is unnecessary to inform those people.The problem is one of optimal control and the number of seats sold and the advertising effort of the organizers are the state and control variables, respectively. We show that, besides being dependent on the cost and revenue parameters, the optimal advertising policy is also affected by the length of the planning period and the relation between the number of seats and the total number of potential attendees.     

Ein Planungsansatz zum Umgang mit Störungen bei der Produktion: Die flexible Produktionsfeinplanung mithilfe von Planungsschritten

Disruptions like the breakdown of machines or delays in the delivery of materials cause generated production plans to be useless, at least in some parts. A new planning approach for coping with this uncertainty caused by disruptions is presented. Planning steps that are described by properties, preconditions and consequences are used for material requirements planning and scheduling. If their preconditions are satisfied in a certain state of environment, planning steps will be applicable. The consequences of planning steps change the state of environment. Each customer order establishes a goal of a new planning problem to be achieved by applying planning steps. Plan execution concerns all planning steps applicable in a certain state of environment. In choosing among applicable planning steps and among available resources the flexibility of plan execution is preserved.     

Polarization and electric field distribution in thermally poledPVDF and FEP

In the present paper, heat wave (LIMM) and pressure step (PPS) measurements of the spatial polarization and electric field distributions in nonuniformly thermally poled α-PVDF and Teflon FEP films are reported. The spatial distributions obtained by the two methods are compared over the entire thickness range, and a satisfactory agreement is found. For PVDF the results of both methods are in accordance with literature data for similarly poled specimens of similar material, the so-called `thermal profile', a polarization peak near the anode. Furthermore, in the LIMM experiments we found a small peak near the cathode, which can be explained by a positive compensation charge layer extending ≈2 μm in depth. For the first time, LIMM spectra of FEP are published. The space charge distribution in the FEP sample is nearly homogeneous inside the sample. Near the anode side an accumulation of negative charges appear. Near both surfaces a positive compensation charge was found with a thickness of ~1 μm. It is demonstrated that by means of our deconvolution the spatial distribution can be determined simultaneously with two thermal parameters, the diffusivity of the sample material and the heat transfer coefficient between sample and sample holder