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21.
Xing Ruan 《Frontiers of Structural and Civil Engineering》2010,4(4):450-455
This essay begins with a reflection on what has been taught in architectural design since the turn of the twentieth century. I shall trace back to the two disciplinary foundations of the French École des Beaux-Arts — parti and poché — in the education of an architect in the eighteenth and nineteenth centuries. I shall then attempt to superimpose parti and poché on a modern disciplinary framework, say that of mathematics, which leads to musings on a series of architectural problems that include pattern versus type, stability versus mobility, orthogonal versus oblique, confinement versus transparency, and aging versus metallic sheen. These paradoxes, I suggest, demand the education of an architect to address both the instrumental pattern of a building configuration and the ambient felt qualities of a room, rather than vision alone. 相似文献
22.
F. A. Nicholson BSc MSc PhD B. J. Chambers BSc PhD A. Moore BSc PhD R. J. Nicholson BSc G. Hickman BSc 《Water and Environment Journal》2004,18(3):155-160
A review was undertaken of (a) the levels and prevalence of Salmonella spp., Campylobacter spp., Listeria monocytogenes, Escherichia coli 0157. Cryptosporidium parvum and Giardia intestinalis in livestock manure, and (b) factors which affect their survival during storage and following land application. Pathogens are commonly present in livestock manures and can survive in soil for several months or years after spreading or excretion onto land. Temperature was identified as being the most important factor influencing pathogen survival, although pH, UV light and drying were also important. Various practical measures to minimise the risk of pathogen transfer into the food chain were identified, including treatment, extended storage and no/harvest periods following land spreading. Guidelines are being developed on managing farm manures to minimise the risks of microbiological contamination of ready-to-eat crops. 相似文献
23.
Ten full-scale test fires were conducted in a chamber simulating a three person ship accommodation quarter. The test fires used three different ventilation conditions, two types of bunks and furnishings with either polyurethane foam or chloroprene foam. The chamber was instrumented to follow the development of the fire.The furnishings with polyurethane foam were readily ignited and produced an intense fire within 2 to 4 minutes. The furnishings with chloroprene foam ignited but burned slowly with a small flame or in smoldering combustion.The ventilation conditions had a significant effect on the development and intensity of the fire as the test fires were burning under oxygen-limiting conditions.The solid pan bunks retarded the early development of the fire compared to open bunks for polyurethane furnishings. However, once the mattresses on the three bunks were ignited the intensity of the test fires was similar for both types of bunks. 相似文献
24.
Spatial competition and regulatory change in the grain handling and transportation system in western Canada 总被引:2,自引:0,他引:2
The grain handling and transportation system (GHTS) has been a defining component of the western Canadian economy since the
early part of the last century. Only two major railways serve the grain handling industry, so the potential for the exercise
of market power in transportation appears to be significant. In fact, spatially oriented regulations applicable to railways
exist in Canada to mitigate this, but to date they have not often been used by shippers. While the reasons for this are not
completely clear, we suggest that the regulations are now inadequate for the current state of the GHTS. Using a unique data
set from the year 2000, we assess the effect on the grain handling industry of modifications to these regulations, and find
that significant gains for shippers from these modifications are possible. These gains are computed to be on the order of
C$10–15 million per year for grain shippers alone.
We would like to thank conference and presentation participants (Transportation Research Board, Canadian Agricultural Economics
Society, University of British Columbia, University of Leeds and California State University, Long Beach) as well as the anonymous
reviewers who commented on the earlier versions of this paper. We would also like to acknowledge support from the Saskatchewan
Department of Highways. 相似文献
25.
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27.
Kyrsten E. Black Jennifer A.H. Lowe Michael F. Billett Malcolm S. Cresser 《Water research》1993,27(7)
River water has been sampled under baseflow conditions in both summer and winter at c. 250-m intervals along the length of each of seven rivers in northeast Scotland, and the nitrate contents have been determined. The resultant data have been examined in the context of the nitrogen saturation hypothesis. Capacity of the catchment soils to retain nitrate was generally minimal in winter. Although biological uptake of nitrate was evident in summer, in the upper part of each catchment substantial nitrate leaching still occurred. The phenomenon was most marked in water draining from hill peats, except where these were conspicuously waterlogged. The results are discussed in the context of possible nitrogen saturation effects on upper catchment slopes. 相似文献
28.
The oxidation of protocatechuic acid with ozone in aqueous solution has been studied varying the temperature, pH, ozone partial pressure and initial acid concentration. A stoichiometric ratio of 2 mol of ozone consumed per mol of protocatechuic acid reacted is deduced from homogeneous experiments in a discontinuous tank reactor.In the ozonation experiments, the influence of the operating variables was established and the kinetic regime of ozone absorption was shown to be fast and pseudo m-order with respect to ozone, except at pH 2, when the reaction develops in the moderate kinetic regime. After applying a mass transfer with chemical reaction model, the reaction orders are deduced and the kinetic rate constants are determined as a function of pH and temperature. A modified Arrhenius expression is proposed to correlate them. 相似文献
29.
In this paper experiments are described in a bio-disc pilot plant. A new method has been developed for a reproducible measurement of the thickness of the waterfilm on the rotating discs. The results were used to calculate the oxygen transfer coefficient into water (KL). The values of KL, calculated in this way, appeared to be considerably higher than experimental KL-values, which is mainly due to the fact that the water layer on the rotating disc is outdistanced by the disc. This effect has not been taken into account in the literature so far. 相似文献
30.
Antonio Alvarez 《The Annals of Regional Science》2007,41(2):431-441
The main contribution of this paper is the implementation of a new model which combines the two parametric approaches most
commonly used in the productivity literature: fixed effects and stochastic frontiers. This allows us to discuss whether it
is better to use average or frontier functions to estimate regional productivity. The empirical section uses panel data of Spanish regions over the period 1980–1995.
Additionally, we calculate and decompose total factor productivity growth for the Spanish regions. 相似文献