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991.
Christoph Stiller Ulrich Bünger Steffen Møller-Holst Ann Mari Svensson Kari A. Espegren Matthias Nowak 《International Journal of Hydrogen Energy》2010
Hydrogen is expected to become an integral part of the Norwegian energy system in the future, primarily as transportation fuel. The NorWays project aims at providing decision support for introduction of hydrogen in the Norwegian energy system by modelling of energy system and hydrogen infrastructure at various spatial levels. GIS-based regional hydrogen demand scenarios and fuelling station networks have been generated, considering organic growth of regional hydrogen coverage and increasing density of hydrogen users over time. A regional model optimised supply scenarios for these fuelling station networks, including choice of production technology (biomass gasification, NG SMR, electrolysis, by-product hydrogen) and delivery (pipeline, truck, and onsite schemes), including integrated hydrogen delivery networks by truck and pipeline. The impact of energy price and GHG emission constraint scenarios on hydrogen production and delivery mix and average hydrogen costs is analysed, and conclusions on the effectiveness of policy measures are drawn. 相似文献
992.
EBZ260H岩巷掘进机在城郊煤矿的应用 总被引:1,自引:0,他引:1
城郊煤矿要实现持续高产,开拓工程满足采区接替是关键。介绍了EBZ260H岩巷掘进机的各部分组成、主要工作原理和使用情况及产生的效益。该岩巷掘进机在岩巷快速掘进中具有推广价值。 相似文献
993.
B. Reggiani L. Donati J. Zhou L. Tomesani 《Journal of Materials Processing Technology》2010,210(12):1613-1623
The present study was aimed to analyze the effect of loading cycles on the behaviour of the AISI H11 tool steel commonly used for aluminium extrusion dies working at high temperatures and under high, cyclic stresses. A technological test method in which the specimen geometry resembled the mandrel of a hollow extrusion die was developed. Finite element analyses were performed to aid in determining specimen geometry and dimensions as well as the levels of stress to be applied to the specimen so as to replicate the conditions typically encountered by industrial hollow extrusion dies. Tests were performed on a Gleeble thermomechanical simulator by heating the specimen using Joule's effect and by applying loading for up to 6.30 h or till specimen failure. Displacements during the tests at 380, 490, 540 and 580 °C and under the average stresses of 400, 600 and 800 MPa were determined. The specimens were tested under creep (with the load held at a fixed value), fatigue (cyclic loading) and creep–fatigue (cyclic loading with a 3 min dwell-time) loading, thereby allowing a direct comparison between different deforming mechanisms. The results showed that the test could physically simulate the cyclic loading on the hollow die during aluminium extrusion and that the creep condition represented the most severe working condition. In addition, the tests could reveal the interaction between creep and fatigue mechanisms. 相似文献
994.
995.
L. Yu. Ferdigalov 《Cybernetics and Systems Analysis》1999,35(6):994-998
To solve the Poisson equation in a rectangular domain, a numerical increased-accuracy method is used. This method is based
on the relationship be Ween the values of the function and its derivatives at neighboring nodes of a net domain. Results of
solution of model problems using this method are presented.
Translated from Kibernetika i Sistemnyi Analiz, No. 6, pp. 176–182, November–December, 1999. 相似文献
996.
A. Suat Bagci 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2013,35(3):221-232
The purpose of this study was to perform wet forward combustion experiments for Bati Kozluca heavy oil under different experimental conditions. In the experiments, a vertical combustion tube was packed with crushed limestone and saturated with crude oil and water. A total of five wet combustion tube runs were conducted. It was observed that peak temperatures were higher when stabilized combustion was achieved and decreased as the combustion front approached the outlet of combustion tube. In wet combustion experiments, excess carbon dioxide productions were observed due to the decomposition of carbonate minerals. The concentration of carbon dioxide increased after the injection of water while the concentration of the oxygen and carbon monoxide decreased. Atomic H/C ratio of the fuel consumed decreased as the average peak temperature increased. Fuel consumption rate also decreased as the water-air ratio increased. The oil recovery was increased with the water injection until the optimum value. After this point, a decrease in oil recovery was observed due to the decrease in peak temperatures in Bati Kozluca crude oil. The main advantage of wet combustion was to reduce air requirements and improve the sweep efficiency by expanding the steam plateau region. Since most of the oil was displaced ahead of the burning front, the steam plateau becomes the primary driving mechanism for oil production. 相似文献
997.
Abstract. In this article, under a semi‐parametric partly linear autoregression model, a family of robust estimators for the autoregression parameter and the autoregression function is studied. The proposed estimators are based on a three‐step procedure, in which robust regression estimators and robust smoothing techniques are combined. Asymptotic results on the autoregression estimators are derived. Besides combining robust procedures with M‐smoothers, predicted values for the series and detection residuals, which allow to detect anomalous data, are introduced. Robust cross‐validation methods to select the smoothing parameter are presented as an alternative to the classical ones, which are sensitive to outlying observations. A Monte Carlo study is conducted to compare the performance of the proposed criteria. Finally, the asymptotic distribution of the autoregression parameter estimator is stated uniformly over the smoothing parameter. 相似文献
998.
Zafer Gezgin & Gurbuz Gunes 《International Journal of Food Science & Technology》2007,42(9):1067-1072
Cig kofte is a traditional Turkish food containing raw ground meat. Samples inoculated with Escherichia coli O157:H7 were irradiated at 0.5–6 kGy with a 60Co source and stored at 4 and 25 °C. Total aerobic mesophilic count decreased with increasing irradiation doses, D10 value was 0.83 kGy. Escherichia coli O157:H7 count decreased from 5.1 log10 CFU g?1 to an undetectable level (<1 log10 CFU g?1) after 1‐day storage at 4 °C following irradiation at 2 kGy, D10‐value was 0.29 kGy. Irradiation doses up to 2 kGy did not affect sensory quality after 1 day. There was colour loss in samples irradiated at 2 kGy or above and stored for longer periods. Storage of the irradiated products at abused temperature must be avoided for safety assurance. Irradiation at 2 kGy has a great potential for extending the shelf‐life of cig kofte and assuring safety by decreasing the number of E. coli O157:H7 and other bacteria, but further studies with suitable package designs are needed to decrease quality degradation during extended storage. 相似文献
999.
Commercially pure titanium and a Ti-6Al-4V alloy covered with a thin thermal oxide film derived from hot rolling were electrolytically hydrogenated in 1N aqueous sulfuric acid solution (H2SO4(aq)) to see the influence of thiourea (H2N-CS-NH2) on the hydrogen uptake of both metals under atmospheric conditions. The inhibitive effect of thiourea was evaluated through quantitative composition analyses (by using a glow discharge spectrometer, GDS) and qualitative microstructural examinations (by using XRD). Thiourea acts as a hydrogenation inhibitor irrespective of the applied current densities. However, the inhibitive effect is more evident at lower charging current densities for longer operating periods. 相似文献
1000.