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61.
A physically based stochastic-deterministic procedure for the estimation of flood frequency 总被引:2,自引:1,他引:1
A procedure based on the method of derived distributions is proposed for the estimation of flood frequency from ungauged watersheds. The results of previous research on rainfall characteristics and watershed response are incorporated into the proposed procedure. These rainfall characteristics are storm depth, storm duration, space and time distribution. A simplified watershed model is used which has previously given good simulation of the watershed response. Some of the rainfall and watershed model parameters are stochastic in nature and are assumed to follow various probability distributions. Monte Carlo simulation is used for the generation of the various parameter values and simulation of the peak flow hydrographs. After 5000 realizations, the frequency of the hourly and daily peak flow and the flood volume is estimated. The proposed procedure is applied to eight coastal British Columbia watersheds and the results compare well with the observed data and with fitted probability distributions. The method is easy to apply, requires limited data and is shown to be reliable. Sensitivity analysis shows that the procedure is not very sensitive to uncertainty of the parameter values and is not dependent on the parameter probability distributions used. 相似文献
62.
Überblick über die Veröffentlichungen auf dem Gebiet des Ringwalzens. Versuchsergebnisse beim Ringwalzen über die Druckverteilung im Walzspalt. Modell für die Abschätzung von Walzkraft und Drehmoment. 相似文献
63.
Jeff H. Harwell Athanasios I. Liapis R. Litchfield Daniel T. Hanson 《Chemical engineering science》1980,35(11):2287-2296
A mathematical model for adiabatic adsorption of multiple components onto a fixed bed of adsorbent is developed. The model consists of a set of coupled, hyperbolic, parial-differential equations. Heat and mass transfer resistances evident in real systems are included in the model. Solutions of the equations are obtained by numerical application of the method of characteristics. Results show non-ideal mass and thermal wavefronts and complex wave-wave interactions in adiabatic adsorption of benzene and cyclohexane onto activated carbon. Phenomena of inversions in relative adsorptivity due to temperature changes are also shown. Column performance is indicated to be greatly affected by these phenomena. Cases considered demonstrate that time on stream before breakthrough may be doubled by increasing influent and initial bed temperatures. It is shown, in contrast to results obtained fron using the non-equilibrium model, that models based on assumptions of local equilibrium cannot quantitatively describe behavior of a typical industrial adsorption system. 相似文献
64.
65.
Wim Verbeke Federico J.A. Pérez-Cueto Marcia D. de Barcellos Athanasios Krystallis Klaus G. Grunert 《Meat science》2010
This paper presents the combined mid-term findings of the consumer research components of two EU Sixth Framework Programme integrated projects concerning meat, ProSafeBeef and Q-PorkChains. The consumer pillar of ProSafeBeef carried out eight focus group discussions in May 2008, in France, Germany, Spain and the UK. Q-PorkChains conducted a large-scale, web-based, consumer survey in January 2008 in Belgium, Denmark, Germany, Greece and Poland. The first project provides a set of qualitative data from a small cohort of focus groups and the second a set of quantitative data from a larger consumer sample. This paper draws together the main findings of both projects and provides a comprehensive overview of European citizens’ and consumers’ attitudes towards and preferences regarding beef and pork. In general, consumers consider meat to be a healthy and important component of the diet. Consumers support the development of technologies that can improve the health attributes of meat products and guarantee eating quality, but they have a negative view of what they see to be excessive manipulation and lack of naturalness in the production and processing of beef products. In the Q-PorkChains study consumer and citizen segments are identified and profiled. Consumer segments were built upon the frequency and variety of pork consumption. The citizen segments were built upon their attitudes towards pig production systems. Overall, the relationship between individuals’ views as citizens and their behaviour as consumers was found to be quite weak and did not appear to greatly or systematically influence meat-buying habits. Future studies in both projects will concentrate on consumers’ acceptance of innovative meat product concepts and products, with the aim of boosting consumer trust and invigorating the European beef and pork industries. 相似文献
66.
67.
Athanasios Stefanou 《Journal of Electronic Materials》2008,37(2):172-175
Four interface models for crystalline oxynitride on (001)Si substrates are proposed and investigated. All four models are
proposed to model thin oxynitride films on Si substrates, according to experimental findings and theoretical studies on amorphous
oxynitride films and nitrogenated SiO2. State-free insulating interfaces were obtained by expanding the bulk oxynitride cell by approximately 12% and 1% along the
[100] and [010] axes, respectively, and interfacing it with (001)Si. Results demonstrate state-free insulating interfaces
for all models with, however, valence-band offsets slightly above or below 1 eV. The significant decrease in the valence-band
offsets is mainly attributed to the significant expansion of the oxynitride’s lattice constant to lattice-matched (001)Si,
as well as to the high concentration of nitrogen atoms in the oxynitride bulk. 相似文献
68.
Vassileios K. Sakarellos Athanasios D. Panagopoulos John D. Kanellopoulos 《Journal of Infrared, Millimeter and Terahertz Waves》2008,29(1):99-111
The ever increasing demand for bandwidth and multimedia services has led to the employment of Ka and V band in modern satellite communication networks. In these frequency bands, rain attenuation is the most dominant fading mechanism deteriorating the performance of the Earth-space links. Moreover, interference due to propagation phenomena increases the outage time of the satellite links and should be taken into account for the reliable design of a satellite communication network. In this paper, a physical propagation model for the prediction of carrier-to-noise plus interference ratio statistics of a broadband satellite link incorporating the receiver noise temperature increase due to rain, is presented The obtained numerical results highlight the significance of the latter effect and investigate the impact of various operational, geometrical and climatic parameters in the total outage analysis. Some simple mathematical formulas for the prediction of the carrier-to-noise plus interference ratio, based on the above theoretical results, are also presented. 相似文献
69.
Stavros Plessas Ann Fisher Katerina Koureta Costas Psarianos Poonam Nigam Athanasios A. Koutinas 《Food chemistry》2008
The application of Kluyveromyces marxianus (IFO 288), Lactobacillus delbrueckii ssp. bulgaricus (ATCC 11842) and Lactobacillus helveticus (ATCC 15009) as starter cultures for sourdough bread making was examined. Production of lactic and acetic acids, bread rising, volatile composition, shelf-life and organoleptic quality of the sourdough breads were evaluated. The amount of starter culture added to the flour, the dough fermentation temperature and the amount of sourdough used were examined in order to optimise the bread making process. The use of mixed cultures led to higher total titratable acidities and lactic acid concentrations compared to traditionally made breads. Highest acidity (3.41 g lactic acid/kg of bread) and highest resistance to mould spoilage were observed when bread was made using 50% sourdough containing 1% K. marxianus and 4% L. delbrueckii ssp. bulgaricus. The use of these cultures also improved the aroma of sourdough breads, as shown by sensory evaluations and as revealed by GC–MS analysis. 相似文献
70.
Pantazopoulos George Vazdirvanidis Athanasios Contopoulos Ioannis 《Journal of Failure Analysis and Prevention》2019,19(3):858-865
Journal of Failure Analysis and Prevention - Failure analysis is performed in electrolytic tough pitch copper plates that have been severely fractured during the initial hot rolling passes. A... 相似文献