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Arie Ben-Zvi 《国际水》2013,38(3):127-133
ABSTRACT The provision of piped water has often been considered a major sanitation measure which will improve the general health of a given population. The associated problems of maintaining a functioning sewerage system so as to insure the quality of the piped water have received increasing recognition. From November 1978 to December 1979, and under varying meteorological conditions, water samples were drawn from ten taps of a piped water supply in an urban slum of Madras, Tamil Nadu, South India. Samples were tested for fecal coliform organisms as an indicator of fecal contamination of water at the taps. Regression analyses were performed on the data, using distance from the tap to the slum's boundary as the independent variable (x) and regressing average log concentration of fecal coliforms (y) during periods of dry and wetter weather, on x. It was found that during wet conditions there was a regression coefficient of +0.972 whereas during dry conditions the regression coefficient was +0.816. The linear regression model suggests that during wet conditions, especially, there is on-site contamination of piped water in the high population density conditions of this urban slum. 相似文献
13.
In their efforts to change organizations, managers and change consultants are time and again confronted with the limited controllability of organizations, the complexity and indeterminacy of change processes and the uncertain and ambiguous effects of their actions. In short, they are confronted with chaos. Some managers and consultants try to enhance their (illusion of) control over organizations by attempting to reduce chaos, while others accept and embrace chaos and base their change practice on it. This article focuses on the second group. Based on a study of literature and a series of interviews with experienced change consultants, a typology is developed, in which an enlightened modern, an ironic, and a postmodern way of coping with chaos in change processes is elaborated. The typology may help change consultants and managers with the development of their way of working and the articulation of their professional identity. 相似文献
14.
The PbZr0.53Ti0.47O3(PZT)/CoFe2O4(CFO) layered nanostructures show lowering of dielectric constant and polarization, and an enhanced magnetization with a decrease in temperature from 400 K to 100 K. The temperature dependence of the real part of the dielectric constant illustrates a step-like behavior, whereas the imaginary part gives a relaxation peak near the step maxima temperature. A slow decrease in the polarization was observed from 300 K to 200 K, with an eventual collapse of polarization at ~ 100 K, and a complete polarization recovery with heating, these phenomena is reproducible over cycles of experiment. Remanent magnetization of the layered nanostructure was found to be three times higher at 100 K than that at room temperature. There is a slow enhancement in remanent (internal) magnetization with lowering of temperature, resulting in slow polarization switch and finally the collapse. The temperature-dependent dielectric, polarization and magnetization were different from the parent layer, indicating a kind of dynamic magneto-electric coupling in the layered nanostructures. 相似文献
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Chun Woo Young; Kruglanski Arie W.; Sleeth-Keppler David; Friedman Ronald S. 《Canadian Metallurgical Quarterly》2011,101(5):1124
This research examines the possibility that people's choices in the service of an explicit focal goal may also reflect their tendency to fulfill implicit background goals and in that sense are multifinal. We carried out 5 experimental studies to investigate this notion. In Experiment 1, a primed implicit goal affected individuals' choices even when those avowedly served an explicit “focal” goal. Experiment 2 replicated this finding with a different type of implicit goals. Experiment 3 found that primed implicit goals had no effect on choices where the options that served them undermined the explicit goal. Experiment 4 found that a primed implicit goal served by a multifinal option does not privilege it over a unifinal option if that goal had been already attained by a different means. Finally, Experiment 5, via 3 types of control groups, showed that choices were affected by both the explicit and implicit goals in isolation, and they shifted toward multifinality when these goals were conjointly present. The discussion considers the integrative potential of the multifinality framework and its implications for a variety of phenomena in the domain of motivated cognition. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
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In this paper, the electrochemical characteristics of semi conductive silicon thin films (n-type and p-type silicon) anodes
integrated with the solid polymer electrolyte for lithium polymer batteries were investigated. The charge/discharge cycling
tests revealed that the phosphorus-doped n-type silicon electrode shows the most stable cyclic performance after the 40th cycle and still maintains a reversible specific capacity of about 2,500 mAh/g. The enhanced electrochemical performance of
the doped silicon anode was attributed to the enhancement of its electrical conductivity, which was further confirmed by impedance
spectroscopy and surface analysis by XPS. 相似文献
19.
R.G. Carvajal A. Torralba J. Tombs F. Muñoz J. Ramírez-Angulo 《Analog Integrated Circuits and Signal Processing》2003,36(3):245-249
A new class AB output stage for CMOS op-amps is proposed with simple and accurate quiescent current control using floating gate transistors. The proposed stage can be operated with a supply voltage close to a transistor's threshold voltage. Experimental results are provided showing a 15 MHz gain-bandwidth product when it is used as the second stage of an op-amp with 1.5 V supply voltage in a standard 0.8 m CMOS technology. 相似文献
20.
K.P. Pipe R.J. Ram 《Photonics Technology Letters, IEEE》2003,15(4):504-506
By measuring the total energy flow from an optical device, we can develop new design strategies for thermal stabilization. Here we present a comprehensive model for heat exchange between a semiconductor laser diode and its environment that includes the mechanisms of conduction, convection, and radiation. We perform quantitative measurements of these processes for several devices, deriving parameters such as a laser's heat transfer coefficient, and then demonstrate the feasibility of thermal probing for the nondestructive wafer-scale characterization of optical devices. 相似文献