Stand und Trends bei der Entwicklung leckfreier oszillierender Verdrängerpumpen

Leakfree oscillating positive-displacement pumps – state of the art and trends of development . Leak- and maintenance-free oscillating positive-displacement pumps are very important for avoiding pollution and improving the reliability of plants. Technical progress in the field of hydraulic diaphragm- and tube-pumps for high pressures are explained. The actual data (pressure, efficiency, temperature) and experience with different fluids are surveyed. The various hydraulic control systems, the diaphragm design, and methods for rupture-control are compared. Further development trends are explained.     

Die Wechselbeziehung von Bauteilverhalten und zeitgeraffter Wettersimulation

Time-lapse weathering of wooden building elements was carried out with the help of a double climate chamber with two sections, one with computer controlled exterior climate, the other with interior climate. This test arrangement enabled reactions of building parts most similar to reactions under natural weather conditions. As related to the building parts construction, time-lapse factors up till 10 were reached (1 year in 36 days). By computerized simulation procedures, which are applied parallel to time-lapsed weathering, building elements, just in their developing state, can be tested for their suitability under certain border conditions. For the technological transfer and for the export of prefabricated houses into regions with deviating climate conditions, the risk of damage can be minimized by this method.     

Classes of design — classes of methods — classes of tools

It is unrealistic to expect one computer-aided design tool to sufficiently support any one given design process. Yet it is necessary to define new CAD programs that give semantic support in design. To this end, the paper first differentiates classes of design and then attempts to establish relations between the defined classes and appropriate methods and computer-aided design tools. In three main sections it describes routine, innovative and creative design; top-down, bottom-up and case-based methods; and a set of corresponding design tools. The purpose of the paper is to make a contribution to the definition of domain specific aspects of CAD and to propose a mapping between processes, methods, and tools.     

Correlation of Ⅲ/Ⅴ semiconductor etch results with physical parameters of high-density reactive plasmas excited by electron cyclotron resonance

Reactive ion etching is the interaction of reactive plasmas with surfaces. To obtain a detailed understanding of this process, significant properties of reactive composite low-pressure plasmas driven by electron cyclotron resonance(ECR) were investigated and compared with the radial uniformity of the etch rate. The determination of the electronic properties of chlorine-and hydrogen-containing plasmas enabled the understanding of the pressure-dependent behavior of the plasma density and provided better insights into the electronic parameters of reactive etch gases. From the electrical evaluation of I(V) characteristics obtained using a Langmuir probe,plasmas of different compositions were investigated. The standard method of Druyvesteyn to derive the electron energy distribution functions by the second derivative of the I(V)characteristics was replaced by a mathematical model which has been evolved to be more robust against noise, mainly, because the first derivative of the I(V) characteristics is used. Special attention was given to the power of the energy dependence in the exponent. In particular, for plasmas that are generated by ECR with EM modes, the existence of Maxwellian distribution functions is not to be taken as a self-evident fact, but the bi-Maxwellian distribution was proven for Ar-and Kr-stabilized plasmas. In addition to the electron temperature, the global uniform discharge model has been shown to be useful for calculating the neutral gas temperature. To what extent the invasive method of using a Langmuir probe could be replaced with the noninvasive optical method of emission spectroscopy, particularly actinometry, was investigated,and the resulting data exhibited the same relative behavior as the Langmuir data. The correlation with etchrate data reveals the large chemical part of the removal process—most striking when the data is compared with etching in pure argon. Although the relative amount of the radial variation of plasma density and etch rate is approximately ?5%, the etch rate shows a slightly concave shape in contrast to the plasma density.     

Light and electron microscope studies on cysts of sarcocystis fusiformis in the muscles of calves infected experimentally with oocysts and sporocysts of isospora hominis Railliet et Lucet, 1891. 1. The development of cyst and cyst wall (author's transl)

In several experiments young calves were infected with isospora hominis sporocysts excreted by human males who had ingested raw beef containing Sarcocystis fusiformis cysts. On the 29th, 48th, 62nd and 98 day p.i. the calves were killed and the development of S. fusiformis cysts in muscle cells was studied by light and electron microscopy. Beginning with the 48th day p.i. numerous cysts containing small numbers of metrocytes only were observed. The cysts developed from a parasitophorous vacuole within the host cells. At first this parasitophorous vacuole was limited by a single unit membrane, which soon became thickened at numberous places inside of the vacuole by osmiophilic material. This complex is called primary wall (equal to Prim?rhülle), reaching a thickness of up to 32 nm in old cysts. This primary wall became regularly folded. forming palisade-like protrusions. On the 62nd day after inoculation these protrusions measured about 2-3 mum in length and 0.5-0.7 mum in diameter. In light microscopy the combined protrusions had the appearance of a radially striated "thick wall", because of their close proximity to each other.     

The influence of wine additives on colour and colour quality of young red wine

Summary Zweigelt 1987, a typical Austrian wine treated with wine additives such as sulphur dioxide,l-ascorbic acid and sorbic acid was stored for 77 days. All characteristic wine components were analysed during the storage period. Only changes in colour could be detected. The changes in the amount of anthocyanins and anthocyanidin chlorides were analysed. The results show that Zweigelt 1987 mixed with wine additives such asl-ascorbic acid or sorbic acid resulted in a larger loss in colour than untreated wine. The changes could be measured photometrically but they were invisible to the naked eye. Appropriate use of wine additives did not appear to deterioriate the ruby colour of young red wine during the period tested.

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Der Einfluß von Wein-Zusatzstoffen auf Farbe und Farbqualität von jungem Rotwein

Zusammenfassung Österreichischer Wein Zweigelt 1987, welcher für die Versuchsreihe unter authentischen Bedingungen hergestellt worden war, wurde mit Weinbehandlungsmitteln wie Schwefeldioxid, Sorbinsäure undl-Ascorbinsäure versetzt. Die Wechselwirkungen der Farbe des Rotweines mit den zugesetzten Chemikalien wurden während einer Lagerzeit von 77 Tagen studiert. Die Anthocyane und Anthocyanidinchloridmengen wurden bestimmt. Die Ergebnisse zeigen, daß Zweigelt 1987, der mitl-Ascorbinsäure bzw. Sorbinsäure versetzt worden war, etwas größere Farbverluste zeigte als unbehandelter Wein. Abschließend wurde festgestellt, daß die Farbveränderungen zwar photometrisch meßbar sind, aber mit freiem Auge nicht erkannt werden. Eine Verwendung dieser Weinbehandlungsmittel in richtiger Dosierung führt zu keiner Verschlechterung der Farbqualität bei jungem Rotwein über den untersuchten Zeitraum.

     

Parameter estimation and optimization techniques for discrete-time semi-Markov models of H.264/AVC video traffic

We investigate a variety of known and new approaches for the estimation of the parameters of discrete-time semi-Markovian traffic models. We focus on modeling video traffic, since the accurate representation of its long-term autocorrelation is a challenge to the parameter estimation methods. The modeling techniques are applied to sample H.264/AVC-encoded video traces. We study their ability to reflect the autocorrelation and variability of the original traffic and also the delay probabilities of a resulting SMP/GI/1 queueing system. The delay probabilities are determined both by simulation and verified analysis of the queue.     

On multicell cooperative transmission in backhaul-constrained cellular systems

Recent work has shown that multicell cooperative signal processing in cellular networks can significantly increase system capacity and fairness. For example, multicell joint transmission and joint detection can be performed to combat intercell interference, often mentioned in the context of distributed antenna systems. Most publications in this field assume that an infinite amount of information can be exchanged between the cooperating base stations, neglecting the main downside of such systems, namely, the need for an additional network backhaul. In recent publications, we have thus proposed an optimization framework and algorithm that applies multicell signal processing to only a carefully selected subset of users for cellular systems with a strongly constrained backhaul. In this paper, we consider the cellular downlink and provide a comprehensive summary and extension of our previous and current work. We compare the performance obtained through centralized or decentralized optimization approaches, or through optimal or suboptimal calculation of precoding matrices, and identify reasonable performance–complexity trade-offs. It is shown that even low-complexity optimization approaches for cellular systems with a strongly constrained backhaul can yield major performance improvements over conventional systems.