Skúšanie opakovanej presnosti polohovania plazmovej rezacej hlavy

Článok stručne opisuje experimentov zameraných na overenie vybraných technologických parametrov plazmového rezacieho stroja. Konštrukčné riešenie tohto stroja predstavuje komplexnú kinematickú štruktúru s deviatimi stupňami voľnosti. Jedným z najdôležitejších parametrov, ktoré sa od stroja požadujú, je dosiahnutie predpísanej opakovanej presnosti polohovania. Úplný návrh experimentov si vyžaduje viac ako tisíc experimentov. preto sa pripravil redukovaný návrh experimentov, ktorý s vyžaduje vykonanie iba 32 experimentov. Predpokladáme pritom iba jedno opakovanie každého experimentu. Ak sa má sledovať aj rozptyl nameraných údajov, vyžaduje sa najmenej päť opakovaní každého experimentu, čo vedie k značnému nárastu ich počtu.Paper briefly describes design of experiments aimed at verification of selected technological parameters of the plasma cutting machine. Design solution of the plasma cutting machine represents a complex kinematic structure with 9 DOF. Reaching the prescribed repeated accuracy of the positioning is one of the main parameters that is required from the machine. Full experiment design covers more than thousands experiments. Therefore reduced experiment design was prepared tehat requires only 32 experiments. We consider only one execution of each experiment. When thae data variability should be observed, five repeating of each experiment is required, resulting in respective increase of the number of experiments

Steam soak predictive model

The steam soak predictive model SSPM has been developed for use in screening studies and feasibility analysis. The SSPM requires only a fraction of the computing time of numerical simulators, but includes most of the phenomena which affect soak performances. The model uses an energy balance which is a refined and extended version of that initially presented by Boberg and Lantz. A simple material balance was developed which incorporates the effects of changing fluid saturations in the results. The theoretical work leading to the model is first presented. This is followed by several sensitivity studies using the SSPM and finally the validation of the model in a comparison of results obtained with the SSPM and field dataPetroleum and Geosystems Engineerin

Degradation of glyphosate in water by the application of surface corona discharges

Glyphosate (GLP) is one of the most widely applied herbicides, and is found ubiquitously in the environment. The removal of glyphosate from waste water and soil is challenging and can be achieved with chemical or biological methods, which, nevertheless, suffer from different disadvantages. The application of a physical plasma for the removal of GLP in water was examined by the application of surface corona discharges in a wire-to-cylinder setup filled with argon. The plasma was ignited at the liquid surface without any additives. By applying a photometric method, GLP was detected after derivatisation with fluorenyl methoxycarbonyl chloride, whereas phosphate was determined with ammonium molybdate. A GLP degradation rate of 90.8% could be achieved within a treatment time of 30 minutes with an estimated energy efficiency of 0.32 g/kWh

AMPA-15N - Synthesis and application as standard compound in traceable degradation studies of glyphosate

Stable isotope labeling of pollutants is a valuable tool to investigate their environmental transport and degradation. For the globally most frequently used herbicide glyphosate, such studies have, so far, been hampered by the absence of an analytical standard for its labeled metabolite AMPA-15N, which is formed during the degradation of all commercially available glyphosate isotopologues. Without such a standard, detection and quantitation of AMPA-15N, e.g. with LC-MS/MS, is not possible. Therefore, a synthetic pathway to AMPA-15N from benzamide-15N via the hemiaminal was developed. AMPA-15N was obtained in sufficient yield and purity to be used as a standard compound for LC-MS/MS analysis. Suitable MS-detection settings as well as a calibration using the internal standard (IS) approach were established for Fmoc-derivatized AMPA-15N. The use of different AMPA isotopologues as IS was complicated by the parallel formation of [M+H]+ and [M]+• AMPA-Fmoc precursor ions in ESI-positive mode, causing signal interferences between analyte and IS. We recommend the use of either AMPA-13C-15N, AMPA-13C-15N-D2 or a glyphosate isotopologue as IS, as they do not affect the linearity of the calibration curve. As a proof of concept, the developed analysis procedure for AMPA-15N was used to refine the results from a field lysimeter experiment investigating leaching and degradation of glyphosate-2-13C-15N. The newly enabled quantitation of AMPA-15N in soil extracts showed that similar amounts (0.05 - 0.22 mg·kg-1) of the parent herbicide glyphosate and its primary metabolite AMPA persisted in the topsoil over the study period of one year, while vertical transport through the soil column did not occur for either of the compounds. The herein developed analysis concepts will facilitate future design and execution of experiments on the environmental fate of the herbicide glyphosate

Accumulation and nuclear import of HIF1 alpha during high and low oxygen concentration in skeletal muscle cells in primary culture

AbstractThe hypoxia-inducible-factor-1 (HIF1) mediates the transcriptional upregulation of several target genes during hypoxia. HIF1 itself is known to be regulated essentially by ubiquitinylation and proteolytic degradation of the subunit HIF1α of the dimeric transcription factor HIF1. In contrast to other tissues, skeletal muscle expresses high amounts of HIF1α in normoxia as well as in hypoxia. In view of this, we aimed to investigate HIF1α accumulation and subcellular localization as well as the transcriptional activity of the HIF1α-regulated gene of glyceraldehyde dehydrogenase (GAPDH) in skeletal muscle cells exposed to low oxygen concentration (3% O2), normoxia (20% O2) or high oxygen concentration (42% O2). Immunofluorescence analysis reveals that under normoxic and high oxygen conditions, significant amounts of HIF1α can be found exclusively in the cytoplasm of the myotubes. Muscle cells treated with CoCl2, a known inhibitor of HIF1α degradation, show even higher levels of HIF1α, again exclusively in the cytoplasm. Under conditions of low oxygen, HIF1α in controls as well as in CoCl2-treated cells is found in the nuclei. CdCl2 inhibits nuclear import of HIF1α at low oxygen concentration and leads to a transcriptional downregulation of the marker enzyme of anaerobic glycolysis GAPDH. Immunoprecipitation with anti-HIF1α antibody co-precipitates HSP90 in an oxygen-dependent manner, more at high pO2 than at low pO2. Cadmium-treated samples also show high amounts of co-immunoprecipitated HSP90, independent of oxygen concentration. We conclude that in skeletal muscle cells, HIF1α, in contrast to other tissues, may, in addition to its regulation by degradation, also be regulated by binding to HSP90 and subsequent inhibition of its import into the nuclei

Strategies for exploiting independent cloud implementations of biometric experts in multibiometric scenarios

Cloud computing represents one of the fastest growing areas of technology and offers a new computing model for various applications and services. This model is particularly interesting for the area of biometric recognition, where scalability, processing power and storage requirements are becoming a bigger and bigger issue with each new generation of recognition technology. Next to the availability of computing resources, another important aspect of cloud computing with respect to biometrics is accessability. Since biometric cloud-services are easily accessible, it is possible to combine different existing implementations and design new multi-biometric services that next to almost unlimited resources also offer superior recognition performance and, consequently, ensure improved security to its client applications. Unfortunately, the literature on the best strategies of how to combine existing implementations of cloud-based biometric experts into a multi-biometric service is virtually non-existent. In this paper we try to close this gap and evaluate different strategies for combining existing biometric experts into a multi-biometric cloud-service. We analyze the (fusion) strategies from different perspectives such as performance gains, training complexity or resource consumption and present results and findings important to software developers and other researchers working in the areas of biometrics and cloud computing. The analysis is conducted based on two biometric cloud-services, which are also presented in the paper

In Memoriam Roger Mohr

Article qui rappelle la carrière scientifique de Roger Moh

Orthorhombic versus monoclinic symmetry of the charge-ordered state of NaV2O5

High-resolution X-ray diffraction data show that the low-temperature superstructure of alpha-NaV2O5 has an F-centered orthorhombic 2a x 2b x 4c superlattice. A structure model is proposed, that is characterized by layers with zigzag charge order on all ladders and stacking disorder, such that the averaged structure has space group Fmm2. This model is in accordance with both X-ray scattering and NMR data. Variations in the stacking order and disorder offer an explanation for the recently observed devils staircase of the superlattice period along c.Comment: REVTEX, 4 pages including 2 figures, shortened, submitted to PR