Pressure release of containments during severe accidents in Switzerland

As required by the Swiss Federal Nuclear Safety Inspectorate (HSK) all Switzerland's five nuclear power plants have to install a containment filtered venting system. The integrity of the containment (the last barrier for radioactive releases to the environment) can be threatened by overpressure due to inadequate heat removal. Design requirements have been provided for a specific class of severe accident scenarios. In general the capacity of the system is considered sufficient if it is able to vent the steam production corresponding to a decay heat level of 1% of the thermal reactor power. The mitigation capacity for the reduction of released radioactive material is specified by a retention factor of 1000 for aerosols to prevent or limit a long term ground contamination and a factor of 100 for elementary iodine for prevention or limiting of thyroid doses and to avoid short term evacuation. Besides existing requirements for design, maintenance and operation, additional claims such as passivity and operability at any pressure conditions inside the containment have to be met. Passivity implies that the system can be initiated after a severe accident without any operator action. The system also has to allow early manual venting. Various filtered venting systems are presently available. The nuclear power plants of Beznau, Gosgen, Leibstadt and Muhleberg have already selected such systems and already implemented them or are going to install them step by step. Beznau selected the Sulzer-EWI system which is using a water pool with nozzles-baffle plates and mixing elements to achieve the required filtration of the aerosols. In both Beznau units, the systems are installed and in standby mode. Gosgen, a pressurized water reactor as well as Beznau, is going to implement a filter system developed by Siemens-KWU, known as sliding pressure venting process, combining a venturi scrubber in a water pool and a mesh filter. The boiling water reactor of Leibstadt also selected the same system as Beznau while Müheberg choose the ABB system but not in the common design. The venturi pipes are thereby integrated in the water pool of the outer torus. The system in all five nuclear power plants is fully operable and in standby mode since December 1993.     

International orientation,efficiency of and regard for research in East and West Germany: A bibliometric investigation of aspects of technology genesis in the United Germany

The efficiency of areas of science was evaluated using the DEA method. Areas achieving a maximum orientation or regard of international publication are rated as efficient. The areas of reproductive medicine, organic and inorganic chemistry in the former Federal Republic can thus be regarded as efficient areas of science. No area of scientific research in the former East Germany was able to achieve the optimum. The determinant in this connection is the adverse situation with respect to international orientation whilst no substantial difference in regard for further research could be detected between East and West German research.     

Slow skeletal troponin I gene transfer, expression, and myofilament incorporation enhances adult cardiac myocyte contractile function

The functional significance of the developmental transition from slow skeletal troponin I (ssTnI) to cardiac TnI (cTnI) isoform expression in cardiac myocytes remains unclear. We show here the effects of adenovirus-mediated ssTnI gene transfer on myofilament structure and function in adult cardiac myocytes in primary culture. Gene transfer resulted in the rapid, uniform, and nearly complete replacement of endogenous cTnI with the ssTnI isoform with no detected changes in sarcomeric ultrastructure, or in the isoforms and stoichiometry of other myofilament proteins compared with control myocytes over 7 days in primary culture. In functional studies on permeabilized single cardiac myocytes, the threshold for Ca2+-activated contraction was significantly lowered in adult cardiac myocytes expressing ssTnI relative to control values. The tension-Ca2+ relationship was unchanged from controls in primary cultures of cardiac myocytes treated with adenovirus containing the adult cardiac troponin T (TnT) or cTnI cDNAs. These results indicate that changes in Ca2+ activation of tension in ssTnI-expressing cardiac myocytes were isoform-specific, and not due to nonspecific functional changes resulting from overexpression of a myofilament protein. Further, Ca2+-activated tension development was enhanced in cardiac myocytes expressing ssTnI compared with control values under conditions mimicking the acidosis found during myocardial ischemia. These results show that ssTnI enhances contractile sensitivity to Ca2+ activation under physiological and acidic pH conditions in adult rat cardiac myocytes, and demonstrate the utility of adenovirus vectors for rapid and efficient genetic modification of the cardiac myofilament for structure/function studies in cardiac myocytes.     

A method to align the coordinate system of accelerometers to the axes of a human body: The depitch algorithm

One of the key problems in accelerometry based gait analyses is that it may not be possible to attach an accelerometer to the lower trunk so that its axes are perfectly aligned to the axes of the subject. In this paper we will present an algorithm that was designed to virtually align the axes of the accelerometer to the axes of the subject during walking sections. This algorithm is based on a physically reasonable approach and built for measurements in unsupervised settings, where the test persons are applying the sensors by themselves. For evaluation purposes we conducted a study with 6 healthy subjects and measured their gait with a manually aligned and a skewed accelerometer attached to the subject's lower trunk. After applying the algorithm the intra-axis correlation of both sensors was on average 0.89±0.1 with a mean absolute error of 0.05g. We concluded that the algorithm was able to adjust the skewed sensor node virtually to the coordinate system of the subject.     

Repairing parts from nickel base material alloy by laser cladding and ball end milling

Due to rising costs of raw material, companies of the aerospace industry increasingly seek to repair components of aircraft engines instead of replacing them. Particularly the clad repair of turbine blades made of high strength nickel-base alloys with directionally solidified or single crystalline structure is a difficult issue, especially due to high requirements regarding the conditions of the final part surface. The present work deals with the question whether the prediction of surface and subsurface conditions, e.g. surface topography and residual stresses, is possible after repairing the inhomogeneous nickel-base alloy Rene 80. For this purpose, laser deposition cladding is applied for the polycrystalline Rene 80, using the filler material Rene 142. In the following re-contouring process, the claddings are milled with a ball end mill cutter. The influence of the inhomogeneous base material and the shape of the clad on the cutting forces as well as the final part surface are experimentally investigated. Superficial residual stresses are measured and evaluated. The cutting forces and the final surface reveal characteristic variations in the area of the material deposition and the dendrites. A geometric process simulation shows that the prediction of cutting forces and surface conditions for the polycrystalline material is only possible to some extent.     

Overview of the local production process of raw milk butter in Wallonia (Belgium)

This study aims to describe the procedures and practices used in local production of raw milk butter. The demand for local products is increasing; hence, there is a need to describe the practices used in the artisanal production of raw milk butter. Therefore, a survey of 147 raw milk butter producers was carried out. The results from the survey indicate that there is not one single way to produce butter at artisanal level. In terms of maturation, six temperature sequences were distinguished. Attention is required at every step of production starting from breeding.     

Test-Driven Development for Spreadsheet Risk Management

Spreadsheet technology is central to the functioning of the financial sector, but professionally created spreadsheets have a high level of error, which highlights the need for innovative supporting processes and tools. The current global financial crisis will likely accelerate this need because anticipated regulation will require novel, innovative risk management methods and technologies that cover development, risk assessment, review, and other spreadsheet activities. These methods will need to be easy to understand and use and will have to serve multiple stakeholders' needs. Test-driven spreadsheet development (TDSD) is one such method. TDSD provides an ideal fit with existing market-leading spreadsheet management processes and can assist managers and auditors in the assessment and control of spreadsheet risk.