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121.
Anne Marie Svane 《Journal of Mathematical Imaging and Vision》2014,49(2):352-376
Local algorithms are common tools for estimating intrinsic volumes from black-and-white digital images. However, these algorithms are typically biased in the design based setting, even when the resolution tends to infinity. Moreover, images recorded in practice are most often blurred grey-scale images rather than black-and-white. In this paper, an extended definition of local algorithms, applying directly to grey-scale images without thresholding, is suggested. We investigate the asymptotics of these new algorithms when the resolution tends to infinity and apply this to construct estimators for surface area and integrated mean curvature that are asymptotically unbiased in certain natural settings. 相似文献
122.
The Water Framework Directive (WFD) defines common objectives for water resources throughout the European Union (EU). Given this general approach to water preservation and water policy, the objective of this paper is to analyse whether common patterns of water consumption exist within Europe. In particular, our study uses two methods to reveal the reasons behind sectoral water use in all EU countries. The first method is based on an accounting indicator that calculates the water intensity of an economy as the sum of sectoral water intensities. The second method is a subsystem input-output model that divides total water use into different income channels within the production system. The application uses data for the years 2005 and 2009 on water consumption in the production system of the 27 countries of the EU. From our analysis it emerges that EU countries are characterized by very different patterns of water consumption. In particular water consumption by the agriculture sector is extremely high in Central/Eastern Europe, relative to the rest of Europe. In most countries, the water used by the fuel, power and water sector is consumed to satisfy domestic final demand. However, our analysis shows that for some countries exports from this sector are an important driver of water consumption. Focusing on the agricultural sector, the decomposition analysis suggests that water usage in Mediterranean countries is mainly driven by final demand for, and exports of, agricultural products. In Central/Eastern Europe domestic final demand is the main driver of water consumption, but in this region the proportion of water use driven by demand for exports is increasing over time. Given these heterogeneous water consumption patterns, our analysis suggests that Mediterranean and Central/Eastern European countries should adopt specific water policies in order to achieve efficient levels of water consumption in the European Union. 相似文献
123.
Different types of enzymes such as lipases, several phosphatases, dehydrogenases, oxidases, amylases and others are well suited for the reactions in SC-CO2. The stability and the activity of enzymes exposed to carbon dioxide under high pressure depend on enzyme species, water content in the solution and on the pressure and temperature of the reaction system. The three-dimensional structure of enzymes may be significantly altered under extreme conditions, causing their denaturation and consequent loss of activity. If the conditions are less adverse, the protein structure may be largely retained. Minor structural changes may induce an alternative active protein state with altered enzyme activity, specificity and stability. 相似文献
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125.
A hypothesis was investigated, to assess if Ni-plating a 3rd-generation single-crystal alloy could favorably alter the diffusion profile of critical elements such that brittle, deleterious topologically close-packed (TCP) phases did not form or at least the extent to which they did was reduced. In conjunction with delaying the onset of these phases, it was hoped that more favorable alternatives could be promoted, such as martensite (β′). This study showed that Ni-plating did have some positive effects on the super-alloy/coating system. While the coating produced on the Ni-plated alloy was thinner, it retained a higher Al content than its unplated counterpart when subjected to oxidation. The retention of Al within the coating delayed the phase evolution of the coating from a β or β + β′ to a γ′-dominant coating as the Ni-plated system had a greater driving force for Ni and Al diffusion, which helped to establish the Ni-rich diffusion barrier that entrapped Al in the coating. Unfortunately, Ni-plating does not sufficiently alter the diffusion profiles within the alloy to prevent precipitation of the TCP phases. Four pairs of the CMSX-10 alloy were used for this study. While they were all aluminized, only half of them, one in each pair, were Ni plated prior to aluminizing. Three of the four pairs were then oxidized at 1423 K (1150 °C), while the first pair was kept as a standard. X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy were used to characterize each alloy-coating system in an effort to better understand their performance under high temperature oxidation. 相似文献
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127.
Delphine Paolucci‐Jeanjean Marie‐Pierre Belleville Gilbert M Rios 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2001,76(3):273-278
Loss of enzyme activity is a problem associated with enzymatic reactions in continuous recycled membrane reactors (CRMR). It may result from catalyst leakage and also enzyme denaturation due to the effects of pH, temperature, shear effects or adsorption/deposit on membrane. In this study, the relative importance of these various factors has been assessed in order to reduce their adverse effects on starch hydrolysis in a CRMR. The effects of temperature and denaturation by adsorption/deposit on membrane were the most limiting phenomena. Reducing the temperature to overcome thermal denaturation was not a practical solution since this increases viscosity and thereby decreases permeate flux and reactor performance. Insofar that adsorption/deposit of enzymes on the membrane is directly linked to membrane fouling, back‐flushing or regularly purging retentate should reduce this phenomenon by lowering accumulation of high molecular weight products. © 2001 Society of Chemical Industry 相似文献
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129.
Tomáš Horák Jiří Čulík Vladimír Kellner Marie Jurková Pavel Čejka 《Journal of the Institute of Brewing》2009,115(3):214-219
Dominant trends in analytical chemistry include miniaturization in sample preparation techniques and faster run times to provide high‐throughput screening, fast process monitoring and fast method development. This study focused on the application of narrow bore gas chromatographic capillary columns, 0.18 mm internal diameter, for brewing analyses. On these capillary columns, faster analyses could be performed compared to conventional GC capillary columns using 0.32 to 0.53 mm internal diameters. The robustness of the state‐of‐the‐art faster capillary gas chromatography, without compromising resolution, has been demonstrated with the analyses of beer flavour compounds such as lower and higher alcohols, esters and other volatile compounds such as acetaldehyde and dimethyl sulphide in beer. These methods were able to reduce sample run times by 60%. 相似文献
130.
Abbas Hodroj Patrick Simon Pierre Florian Marie‐Hélène Chopinet Yann Vaills 《Journal of the American Ceramic Society》2013,96(8):2454-2460
The morphological and structural properties of sodium silicate (Na2O–SiO2) glasses were analyzed using atomic force microscopy (AFM) and light scattering following thermal treatments. AFM observations indicated that the glass surface microstructure evolves during the phase separation mechanisms from continuous interpenetrating phases in the spinodal decomposition process to separated droplets embedded in a continuous matrix for the nucleation/growth one. Raman mapping gave evidence of a phase separation through the nucleation/growth process with formation of silica‐rich clusters characterized by higher polymerization degree as separate droplets. The variations in inhomogeneities versus temperature investigated by Brillouin are exponential for spinodal decomposition and linear in the case of nucleation/growth mechanism. Nuclear magnetic resonance spectroscopy was used to investigate the spatial distribution of the various Qn species present in thermally treated glasses and allows determining fractal dimension between two and three. 相似文献