Coflow jets with large velocity difference - a new aerodynamic principle of flame stabilization and combustion intensification

A new aerodynamic principle of flame stabilization and combustion intensification, the coflow jets with large velocity difference, is described. One or more small high-velocity jets of air or steam, injected off the axis and in the same direction as the low-velocity main fuel-air flow into the combustor, create a large recirculation zone of high turbulence intensity in which the combustibles and high temperature gases are effectively mixed, so that stable and intensive combustion can be maintained even for fuels with poor ignition. A pulverized coal combustor based on the principle mentioned above is shown to be characteristic of excellent combustoom and a simple structure. A number of precombustors of this type are in operation at some power stations and industrial boilers of China. Using such precombustor, successtul startups and part-load operation of the boilers have become available under conditions of unpreheated air and low-grade coal with volatiles as low as 15% and ash content as high as 30%. This principle shows good promise as an attractive new technology of combustion.

Dynamic-response of a laminated plate with friction damping

沉降对不同粒径聚苯乙烯胶乳球异向聚集的影响

R.Folkersma等报道了在微重力环境下2μm聚苯乙烯（PS）胶乳球的异向聚集速率有明显增大的结果,本文作者之一孙祉伟等的实验结果却与此有很大差异.为此作者在孙祉伟等的实验基础上对1,2,3μm以及1μm+2μm PS胶乳球混和体系的相对聚集速率进行了研究.作者对原有实验装置进行了改进,并验证了改进后的实验装置的可行性.用密度匹配法实现模拟微重力条件,用快聚集过程中浊度随时间的变化表示相对聚集速率.结果表明,重力引起的沉降对所研究体系聚集速率的影响是很小的,在实验误差范围内可以忽略.作者认为与Stein等结果显著不同的原因是二者使用的样品表面性质不同以及实验方法的差异.

On the strategic equivalence of multiple-choice test scoring rules

A disadvantage of multiple-choice tests is that students have incentives to guess. To discourage guessing, it is common to use scoring rules that either penalize wrong answers or reward omissions. These scoring rules are considered equivalent in psychometrics, although experimental evidence has not always been consistent with this claim. We model students' decisions and show, first, that equivalence holds only under risk neutrality and, second, that the two rules can be modified so that they become equivalent even under risk aversion. This paper presents the results of a field experiment in which we analyze the decisions of subjects taking multiple-choice exams. The evidence suggests that differences between scoring rules are due to risk aversion as theory predicts. We also find that the number of omitted items depends on the scoring rule, knowledge, gender and other covariates.

A Non-Parametric Dimension Test of the Term Structure

Published as an article in: Studies in Nonlinear Dynamics & Econometrics, 2004, vol. 8, issue 3, article 6.

Randomized, double-blind, placebo-controled clinical trial of sublingual immunotherapy in natural rubber latex allergic patients

Trial registration number: CTRN12611000543987

Test well exploration in the Myakka River Basin area, Florida

In recent years, difficulties encountered in obtaining ground-water supplies with acceptable chemical characteristics in the Myakka River basin area led to the implementation of a test drilling program. Under this program, well drilling and data collection were executed in such a manner that all water-producing zones of the local aquifers, together with the quality and quantity of the water available, were effectively identified. A step-drilling method was utilized which allowed the collection of formation cuttings, water samples, and water-level data, from isolated zones in the well as drilling proceeded. The step drilling procedure is described. The driller's logs, geophysical logs, and chemical quality of water tables are presented.(Document has 66 pages.)

¿Cómo podemos distinguir a los vendedores éticos de los que no lo son?: Implicaciones para el proceso de selección y formación de los comerciales

[ES] Actualmente las organizaciones necesitan dar prestigio a sus equipos de ventas, conocedoras de la influencia que tienen los vendedores sobre el éxito o fracaso de la empresa y de la deteriorada imagen que la sociedad ha tenido tradicionalmente de los vendedores, debido en parte, a la utilización de prácticas éticamente cuestionables por parte de los mismos.

Can the change in the composition of the US GDP explain the Great Moderation? A test via oil price shocks

The paper investigates whether the growing GDP share of the services sector can contribute to explain the great moderation in the US. We identify and analyze three oil price shocks and use a SVAR analysis to measure their economic impact on the US economy at both the aggregate and the sectoral level. We find mixed support for the explanation of the great moderation in terms of shrinking oil shock volatilities and observe that increases (decreases) in oil shock volatilities are contrasted by a weakening (strengthening) in their transmission mechanism. Across sectors, services are the least affected by any oil shock. As the contribution of services to the GDP volatility increases over time, we conclude that a composition effect contributed to moderate the conditional volatility to oil shocks of the US GDP.