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91.
O. Lüning und Stephan Gerö 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1925,49(4):179-187
Ohne ZusammenfassungMitteilung aus der Nahrungsmittel-Untersuchungsstelle an der Technischen Hochschule in Braunschweig. 相似文献
92.
Nikolaj Krasokha Sebastian Weber Stephan Huth Kathrin Zumsande Werner Theisen 《Metallurgical and Materials Transactions A》2012,43(11):4237-4246
This work deals with gas?Csolid interactions between a high-alloyed steel powder and the surrounding atmosphere during continuous heating. It is motivated by the recently developed corrosion-resistant CrMnCN austenitic cast steels. Here, powder metallurgical processing would be desirable to manufacture highly homogeneous parts and/or novel corrosion-resistant metal-matrix composites. However, the successful use of this new production route calls for a comprehensive investigation of interactions between the sintering atmosphere and the metallic powder to prevent undesirable changes to the chemical composition, e.g., degassing of nitrogen or evaporation of manganese. In this study, dilatometric measurements combined with residual gas analysis, high-temperature X-ray diffraction (XRD) measurements, and thermodynamic equilibrium calculations provided detailed information about the influence of different atmospheric conditions on the microstructure, constitution, and densification behavior of a gas-atomized CrMnCN steel powder during continuous heating. Intensive desorption of nitrogen led to the conclusion that a vacuum atmosphere is not suitable for powder metallurgical (PM) processing. Exposure to an N2-containing atmosphere resulted in the formation of nitrides and lattice expansion. Experimental findings have shown that the N content can be controlled by the nitrogen partial pressure. Furthermore, the reduction of surface oxides because of a carbothermal reaction at elevated temperatures and the resulting enhancement of the powder??s densification behavior are discussed in this work. 相似文献
93.
Waste disposal and waste avoidance are examined from two different perspectives, from the point of view of the waste 'producing' company on the one hand, and from the point of view of the waste disposing company on the other hand. The idea of the basic model lies in the 'turning upside down' of the lot-sizing approach to inventory control theory. We derive a corresponding formula for disposal that shows that the number of waste disposals depends positively on the waste accumulation rate and negatively on the fixed costs for a pick-up. Moreover, we formally work out at which waste avoidance costs a company will enlist the services of a disposal company. Specifically, disposal tends to be preferred to avoidance when waste-avoidance is relatively expensive and three cost rates to be specified are relatively low. Finally, we take the perspective of a monopolistic disposal company that has to decide on the optimal pricing policy. In our model, we determine that the price for a pick-up should be chosen just to cover costs. The disposal company can earn a profit by the suitable choice of the price per unit waste to be disposed of. 相似文献
94.
Damien Serret Stephan Guignard Lounès Tadrist 《Microgravity science and technology》2009,21(1-2):101-105
Heat transfer prediction under boiling condition is still unresolved. In this paper, a basic study on bubble growth is carried out. Recent works show that contact line region plays an important role for heat and mass transfer in nucleate boiling regime. Three dimension experimental set-up lead to a mirage effect which disturbs measurements. To overcome this problem, a new quasi two dimensional experimental set-up is designed. This Hele–Shaw like configuration allows measuring the contact angle and contact line displacement during the bubble growth. A noticeable behavior of the contact angle is observed, and the influence of the sub-cooling level on the bubble growth rate and the contact angle value is studied. 相似文献
95.
Filip Alexandrescu Petr Klusáček Stephan Bartke Robert Osman Bohumil Frantál Stanislav Martinát Josef Kunc Lisa Pizzol Alex Zabeo Elisa Giubilato Andrea Critto Alena Bleicher 《Clean Technologies and Environmental Policy》2017,19(5):1323-1334
This article deals with experiences acquired during the process of developing the Timbre Brownfield Prioritization Tool (TBPT). Developing a decision support tool that takes into account the expectations and experiences of its potential users is similar to creating applicable knowledge by the joint action of scientists and heterogeneous actors. Actor network theory is used to explore the construction of this form of applicable knowledge as a process of actor network creation. Following the French sociologist Callon, networks are seen to be initiated and carried out by a group of scientists (tool developers) via four moments of translation, called problematization, interessement, enrolment and mobilization. Each step in the construction of the TBPT—from the initial research question to the final model—can be linked in retrospect to changing configurations of actor networks. Based on the experiences of the tool developers in the Czech Republic, Poland, Germany and Romania, we illustrate how these configurations varied across space and time. This contribution emphasizes the ability to correlate gains in knowledge with the more visible changes in the scope of actor networks in order to highlight achievements but also limitations in acquiring applicable knowledge. 相似文献
96.
97.
Carbon nanotube papers (CNT papers, also referred to as “buckypapers”) prepared from chemically functionalized single-walled CNTs are being investigated for their mechanical tensile properties. While the Young’s moduli are unaffected by the functionalization with diazonium salts of aniline or aromatic mono- and bis-amides tensile strengths of CNT papers are found to increase with a growing degree of functionalization, and more pronounced with a growing number of amide groups capable of hydrogen bonding. The importance of hydrogen bonding becomes evident after its inhibition through N-methylation of the amide groups, resulting in a distinct reduction of strength values. Scanning electron micrography indicates that a high degree of functionalization or a high number of amide group results in the formation of domains with aligned CNTs. 相似文献
98.
Stephan van Reenen Piotr Matyba Andrzej Dzwilewski René A. J. Janssen Ludvig Edman Martijn Kemerink 《Advanced functional materials》2011,21(10):1795-1802
Incorporation of ions in the active layer of organic semiconductor devices may lead to attractive device properties like enhanced injection and improved carrier transport. In this paper, we investigate the effect of the salt concentration on the operation of light‐emitting electrochemical cells, using experiments and numerical calculations. The current density and light emission are shown to increase linearly with increasing ion concentration over a wide range of concentrations. The increasing current is accompanied by an ion redistribution, leading to a narrowing of the recombination zone. Hence, in absence of detrimental side reactions and doping‐related luminescence quenching, the ion concentration should be as high as possible. 相似文献
99.
Stephan Renner 《Datenschutz und Datensicherheit - DuD》2011,35(8):524-529
In ?sterreich wurden Ende 2010 die rechtlichen Grundlagen für die Einführung von elektronischen Z?hlern (Smart Meters) geschaffen.
Datenschutz und der Schutz der Privatsph?re spielen dabei eine bedeutende Rolle. Vor der Einführung intelligenter Messger?te
ist jedenfalls zu definieren, zu welchen Zwecken Daten notwendig sind. 相似文献
100.