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91.
The purpose of this paper is to analyze long-run electricity demand behavior in the Swedish mining industry with special emphasis on the impact of energy prices and private research and development (R & D) on electricity use. Methodologically, we estimate a generalized Leontief variable cost function using a panel data set of nine mining operations over the time period 1990–2005. Since the lower boundary of a set of short-run cost functions confines the long-run cost function, we can compute the long-run own- and cross-price elasticities of electricity demand. The empirical results indicate that long-run electricity demand in the mining industry is sensitive to changes in the own price, and already in a baseline setting Swedish mining companies tend to allocate significant efforts towards improving energy efficiency, in part through private R & D. From a policy perspective, the results imply that taxes (and tax exemptions) on electricity can have significant long-run impacts on electricity use. Moreover, future evaluations of so-called voluntary energy efficiency programs must increasingly recognize the already existing incentives to reduce energy use in energy-intensive industries. 相似文献
92.
We present a detailed study of the synthesis of C60 nano- and microrods as well as crystals with normal shapes by the evaporation of C60 solutions based on different aromatic solvents. C60 nano- and microrods are grown with high yield by vaporizing C60 solutions in meta-isomers of aromatic solvents on different substrates while para-isomers give a different type of growth leading to highly crystalline two- and three-dimensional nano- and microcrystals with fcc structure. The role of solvent properties was investigated by using positional isomers containing different halogen radicals. The as-grown crystal rods form hexagonal structures but transform into fcc structure on annealing in vacuum. IR and EDX analysis indicate that solvents remain in the hexagonal nano- and microrods, while it is hard to detect any trace of solvents in the two- or three-dimensional nano- and microcrystals. Furthermore, we present direct proof of the nucleation-growth mechanism for C60 rods. By the vaporization method, the solubility of C60 in the studied halogen aromatic solvents is found to correlate with the diameter distribution of the C60 rods and we suggest that the chemical affinity of the aromatic solvent molecules to C60 may determine its ability to force C60 to form rod-shaped crystals. 相似文献
93.
Patrik Schumacher 《Architectural Design》2016,86(4):128-133
With the countryside becoming ever more sparsely populated as fewer people are needed to keep rural enterprises running, is there any point in engaging architects there? Patrik Schumacher , partner at Zaha Hadid Architects, argues that their time and skills are put to better use in cities, where buildings impact a far greater number of individuals and their social and cultural functionality is more important. Engineers, meanwhile, are perfectly equipped to devise generic solutions for the rural realm. 相似文献
94.
Vladimir Pletser Josef Winter Fabienne Duclos Thierry Bret-Dibat Ulrike Friedrich Jean-Francois Clervoy Thierry Gharib Frederic Gai Olivier Minster Patrik Sundblad 《Microgravity science and technology》2012,24(6):383-395
Aircraft parabolic flights provide repetitively short periods of reduced gravity and are used to conduct scientific and technology microgravity investigations, to test instrumentation prior to space flights and to train astronauts before a space mission. Since 1997, ESA, CNES and DLR use the Airbus A300 ZERO-G, currently the largest airplane in the world for this type of experimental research flight. This mean is managed by the French company Novespace. Since 2010, Novespace offers the possibility of flying reduced gravity levels equivalent to those on the Moon and Mars achieved repetitively for periods of more than 20?s. ESA, CNES and DLR issued an international call for experiments inviting European Scientists to submit experiment proposals to be conducted at these partial gravity levels. The scientific objectives are on one hand to obtain results at intermediate levels of gravity (between 0 and 1?g) allowing a better study of the influence of gravity, and on the other hand to give them some elements to prepare for research and exploration during space flights and future planetary exploration missions. ESA, CNES and DLR jointly organised in June 2011 the first Joint European Partial-G Parabolic Flight campaign with 13 experiments selected among 42 received proposals. Parabolas were flown during three flights providing micro-, Moon and Mars gravity levels with duration typically of 20?s, 25?s and 32?s with a mixed complement of investigations in physical and life sciences and in technology. The paper presents the approach taken to organise this campaign and the 13 selected experiments with some preliminary results are presented to show the interest of this unique research tool for microgravity and partial gravity investigations. 相似文献
95.
Electrochemical oxidation of metals, in solutions where the oxide is somewhat soluble, produces anodic oxides with highly regular arrangements of pores. Although porous aluminium and titanium oxides have found extensive use in functional nanostructures, pore initiation and self-ordering are not yet understood. Here we present an analysis that examines the roles of oxide dissolution and ionic conduction in the morphological stability of anodic films. We show that patterns of pores with a minimum spacing are possible only within a narrow range of the oxide formation efficiency (the fraction of oxidized metal atoms retained in the film), which should exist when the metal ion charge exceeds two. Experimentally measured efficiencies, over diverse anodizing conditions on both aluminium and titanium, lie within the different ranges predicted for each metal. On the basis of these results, the relationship between dissolution chemistry and the conditions for pore initiation can now be understood in quantitative terms. 相似文献
96.
A twin-core fiber Michelson interferometer is evaluated as a high-temperature sensor. Although linear and reproducible operation up to 300°C is obtained, at higher temperatures (700°C) the refractive index shifts plastically and hysteresis is observed, rendering an untreated sensor head unusable. The shift is shown to be greatly reduced by an annealing process of the fiber for 10 h at 900°C, with which the linear response is preserved. 相似文献
97.
Xin Zhou Si-Ming Wu Patrik Schmuki 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(43):2303306
In the present work, the spontaneous dewetting of thin Au layers on single crystalline anatase nanosheets into narrow-disperse Au nanoparticles is investigated. Patterns of the Au particles can be formed on the main facets of anatase that provide a high co-catalytic activity for photocatalytic generation of H2. Dewetting is distinctly influenced by the respective facets (001) and (101), the deposit thickness, and secondary thermal dewetting, but most strongly by the surface termination of the nanosheets. Fluoride termination not only leads to an enhanced Au-phobic behavior but strongly affects the co-catalytic activity for photocatalytic generation of H2. While fluoride termination with or without Au decoration is detrimental for hole transfer, the interplay of the Au co-catalyst and surface fluoride yields highly beneficial effect for electron transfer. This results in a three-times higher photocatalytic H2 production for the F-terminated surface. The findings suggest that dewetting of Au on surface fluorinated TiO2 is an effective way to modulate surface dewetting and achieve a strongly enhanced photocatalytic activity. 相似文献
98.
Biological volatilization of selenium, Se, in a contaminated area is an economical and environmentally friendly approach to phytoremediation techniques, but analytical methods for monitoring and studying volatile compounds released in the process of phytovolatilization are currently limited in their performance. Thus, a new method for real time quantification of trace amounts of the vapors of hydrogen selenide (H(2)Se), methylselenol (CH(3)SeH), dimethylselenide ((CH(3))(2)Se), and dimethyldiselenide ((CH(3))(2)Se(2)) present in ambient air adjacent to living plants has been developed. This involves the characterization of the mechanism and kinetics of the reaction of H(3)O(+), NO(+), and O(2)(+?) reagent ions with molecules of these compounds and then use of the rate constants so obtained to determine their absolute concentrations in air by selected ion flow tube mass spectrometry, SIFT-MS. The results of experiments demonstrating this method on emissions from maize (Zea mays) seedlings cultivated in Se rich medium are also presented. 相似文献
99.
Jan‐Marten Seitz Eric Wulf Patrik Freytag Dirk Bormann Friedrich‐Wilhelm Bach 《Advanced Engineering Materials》2010,12(11):1099-1105
Magnesium alloys present an alternative to medical cases in which polymeric sutures may not be ideal. To date, no efficient and low‐cost manufacturing process for the fabrication of magnesium‐based sutures can be found. To obtain an alternative, the previously characterised magnesium alloys ZEK100 (98% Mg), AX30 (96.2% Mg), AL36 (91% Mg) and MgCa0.8 (99.2% Mg) were cast, extruded into 30 mm diameter bars and extruded into 0.5 mm diameter wires. To determine the mechanical properties of the wires, grain size measurements, tensile tests as well as qualitative bending tests were carried out. The ZEK100 alloy's wires showed the finest microstructure having grains of 1.2 µm in diameter. Coarser microstructures were observed for MgCa0.8, AX30 and AL36. The alloy ZEK100 had the highest tensile stress (367 MPa) also revealing a brittle behaviour due to its fine microstructure. The tensile test, carried out for AX30 as well as AL36, resulted in comparable high fracture strains (10.6%) and tensile stresses (300 MPa). However, MgCa0.8 showed a tensile strength of 315 MPa and a low strain of 1.6%. Within the qualitative bending test wires made of the alloy AL36 were able to form tight knots, which is a key feature for suture applications. The comparison of the magnesium sutures with commercially available polymeric sutures revealed lower strength and elongation for the magnesium alloys. Yet, the wires exhibited mechanical properties that can meet the requirements of a suture material. 相似文献
100.