最新艾伯纳工业炉使用氢气保护气氛的优势分析

位于奥地利林茨的艾伯纳工业炉公司拥有分别位于美国和中国的两家子公司，生产用于对钢、铝和铜金属进行热处理的设备。主要生产对钢材进行热处理的强对流罩式退火炉、立式光亮退火生产线及调制生产线，此三类产品大约占总产量的60％。前两种类型的设备是以100％氢气作为过程保护气氛的，同时一些调制线也使用100％氢气作为过程保护气氛。为了更好的比较使用氢气作为保护气氛的突出效果，通过实例来证明当氢用于罩式退火炉及连续热处理生产线时所具有的优势。     

Plasma and red blood cell total phospholipid fatty acid status of nonpregnant female Vervet monkeys (Cercopithecus aethiops) on a high carbohydrate maintenance diet

A sexually intact, male Chihuahua and a spayed female poodle were presented with left perineal masses. The masses were identified as perineal hernias by rectal palpation. Surgical exploration of the perineal region in each dog revealed retroperitoneal fat protruding between the sacrotuberous ligament and the coccygeus muscle (sciatic perineal hernia). The hernias were repaired using modifications of the standard or internal obturator flap herniorrhaphies. The levator ani muscle was grossly and histologically normal in the Chihuahua and grossly normal in the poodle. No short- or long-term complications were reported in either case. The management of sciatic perineal hernia is similar to the more common caudal perineal hernia.     

Permeation and Sorption of Water and Gases Through EVA Copolymers Films

The transport of water and gases (pure oxygen and carbon dioxide) through poly(ethylene-co-vinyl acetate) (EVA) films of different VA contents and through a low density polyethylene LDPE (used as reference with 0 wt.% VA), was analysed by permeation and sorption measurements. In the case of water, for EVA of 70 wt.% VA, a plasticization effect on the material was observed. For EVA of 19 wt.% VA, there was no plasticization, while for EVA of 4.5 wt.% VA and for LDPE, the water diffusion coefficient decreases with increasing water. An empirical law was then found to account for the reduction of the water diffusivity. A negative plasticization effect was attributed to the formation of water clusters in these rather non polar polymers. This latter result was confirmed by sorption measurements and infra-red spectroscopy. The increase in water sorption extent with the VA content leads to a steady increase in the water permeability in the EVA copolymers. In the case of gas permeation, both for O₂ and CO₂ and whatever the VA content of the copolymer used, the experimental curves are characterized by a constant diffusion coefficient. This is confirmed by sorption experiments. In terms of gas permeability, EVA copolymers are characterized by low coefficients especially for oxygen. In the EVA rubbery copolymers, The O₂ solubility coefficient does not increase with the VA content due to the lack of polar interactions, while the CO₂ one increases due to the overall interactions between CO₂ induced dipoles and the polar the VA carbonyl groups. For these copolymers, the H₂O/CO₂ and H₂O/O₂ selectivities are very high. The experimental values of the selectivities indicate that these EVA copolymers appear as good candidates for applications using high perm-selectivity properties. Electronic Publication     

Keratinizing dermatoses. Combined data from four centers on short-term topical treatment with tretinoin

In four medical centers, 40 patients with keratinizing dermatoses were treated with topical tretinoin (vitamin A acid) 0.1% cream and salicylic acid 2% cream in a short-term, double-blind study. Tretinoin was the more effective treatment for several of the keratinizing dermatoses with the exception of palmar-plantar hyperkeratosis, for which it was not effective in the concentration and method of application used. The most striking clinical responses occurred in patients with lamellar ichthyosis and ichthyosis vulgaris. Local adverse reactions-chiefly pruritus, erythema, burning, excoriation, and irritation-were not severe and could be controlled by modification of the treatment regimen.     

The importance of market interdependencies in modeling energy systems - The case of the European electricity generation market

The analysis of complex electricity generation systems such as the European one require large scale models based on extensive databases of the relevant infrastructures. Such models are increasingly used to assist policymaking by developing scenarios to investigate the impact of certain policies on generation capacities, investments and prices. The continuing liberalization and interconnection of energy markets thereby requires the considerations of multiple interdependencies with other markets. Most models, however, do not take this into account. This paper develops and applies a large scale electricity investments and dispatch and natural gas market dispatch model to highlight the importance of recognizing interdependencies between power generation and the gas market. In an exemplary analysis, it is demonstrated that seasonal gas price patterns resulting from temperature-dependent household gas demand have a significant impact on the competitiveness of gas-fired power stations in competition with other technologies. Spatially, we show that competitive cost-based gas prices would lead to a relocation of such plants closer to the sources of natural gas.     

Expanding the small molecular toolbox to study big biomolecular machines

Ion channels are transmembrane protein complexes that are found in virtually all cells. They fulfill a crucial physiological function by facilitating communication between and within cells. Consequently, impaired channel function, e.g. due to mutations, often has profound physiological effects. Their central role in cell-to-cell communication makes ion channels formidable drug targets, albeit their transmembrane nature often hampers efforts to obtain high resolution structures and hence impedes drug discovery. Decades of electrophysiology and molecular biology studies have made critical contributions to our understanding of ion channel structure and function. Small organic compounds, acting as either agonist or antagonist, have played vital roles in such studies and in recent years these molecular tools have become more sophisticated. Decorated with fluorescent, photoaffinity and/or affinity tags small molecular tools enable imaging, binding site mapping and isolation of biomolecular targets. Here, some of the methodologies employed in the context of ion channels are discussed and highlighted with representative examples.     

Cardiorespiratory and efficiency responses during arm and leg exercises with spontaneously chosen crank and pedal rates

The aim of this study was to compare the cardiorespiratory and efficiency responses between upper (T(UBE)) and lower (T(LBE)) body exercises at the same relative power outputs and with spontaneously chosen crank (SCCR) or pedal (SCPR) rates. Twelve participants performed exercise bouts set at 20, 40, 60 and 80% of maximal power (MP) separated by passive recovery periods. Oxygen uptake, ventilation, gross and work efficiencies during T(LBE) were significantly (P < 0.05) higher than during T(UBE). These results suggest that these responses were not directly related to the relative intensities. However, no significant difference was found for delta efficiency and heart rate values. During T(UBE) and T(LBE), gross efficiency increased significantly (P < of MP for T(UBE) and T(LBE) and the same SCCR and SCPR could explain these results. The present results confirm that the cardiorespiratory and efficiency responses between arm and leg exercises are not always similar, although the power output are normalized in relation to MP and add to the understanding of differences between upper and lower body.