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101.
102.
This paper presents a procedure to predict monthly-mean hourly values of relative humidity, ambient temperature and wind velocity for an Indian location. Three maps, showing distribution of annual-average hourly values of humidity, temperature and wind velocities, are prepared from the analysis of available meteorological data of 205 Indian cities. An equation is obtained for annual-average temperature as a function of altitude of the location. Sets of equations are then developed to predict the said weather parameters by the least square regression analysis of the data of 14 cities, taken from different regions, out of 19 cities for which detailed weather data was available. A ratio of monthly-mean to the yearly-mean value of variable is correlated with month and then hourly to the monthly-mean value is correlated with day-hours. On comparison of the computed results with the measured data of the remaining 5 cities, yearly-average relative standard deviations are 14.6, 10.5 and 26.7% for monthly-mean hourly relative humidity, ambient temperature and wind velocities, respectively. 相似文献
103.
104.
In the past few years, multi-objective optimization algorithms have been extensively applied in several fields including engineering design problems. A major reason is the advancement of evolutionary multi-objective optimization (EMO) algorithms that are able to find a set of non-dominated points spread on the respective Pareto-optimal front in a single simulation. Besides just finding a set of Pareto-optimal solutions, one is often interested in capturing knowledge about the variation of variable values over the Pareto-optimal front. Recent innovization approaches for knowledge discovery from Pareto-optimal solutions remain as a major activity in this direction. In this article, a different data-fitting approach for continuous parameterization of the Pareto-optimal front is presented. Cubic B-spline basis functions are used for fitting the data returned by an EMO procedure in a continuous variable space. No prior knowledge about the order in the data is assumed. An automatic procedure for detecting gaps in the Pareto-optimal front is also implemented. The algorithm takes points returned by the EMO as input and returns the control points of the B-spline manifold representing the Pareto-optimal set. Results for several standard and engineering, bi-objective and tri-objective optimization problems demonstrate the usefulness of the proposed procedure. 相似文献
105.
106.
Oxidation process control plays a key role in influencing the development of carbon fiber properties. The characterization of oxidized fibers is difficult because of their poor solubility in organic solvents and strong absorbance. X-ray photoelectron spectroscopy (XPS) has been used in the surface characterization of carbon fiber precursors during the oxidation or stabilization process. The changes in surface elemental composition and functionalities of carbon and oxygen have been identified. Quantitative changes have been noticed in surface functional groups as the oxidation process proceeds. © 1994 John Wiley & Sons, Inc. 相似文献
107.
Kelli Hoover Mahesh Bhardwaj Nancy Ostiguy Owen Thompson 《Materials Research Innovations》2002,6(5-6):291-295
Conventional wisdom stipulates that high power ultrasound without direct or indirect transducer contact with the medium to
be treated is not possible. This seemingly correct notion is based upon two major hurdles: inefficient transmission of ultrasound
from the piezoelectric material into air/gases and exorbitant attenuation of ultrasound by gases. The latter is a natural
phenomenon about which nothing can be done, and the former requires an un-conventional approach to transducer design. After
many years of R& D in this area, we have finally succeeded in producing transducers that generate immense acoustic pressure
in air in the frequency range of ∼50 kHz→10 MHz. By using these transducers without any contact with the material, we demonstrate
destruction of 99.9% of dried bacterial spore samples of a close relative of anthrax, Bacillus thuringiensis. Following further refinement of the transducers and the mechanism of their excitation, we anticipate that non-contact ultrasound
will have numerous applications including inactivation of agents of bioterrorism and sterilization of medical and surgical
equipment, food materials, and air-duct systems of buildings, airplanes, space stations, and others.
Electronic Publication 相似文献
108.
A two-compartment electrochemical photocell using nickel-based polycrystalline CdSe, CdS, and mixed chalcogenides showed promising potential for constructing regenerative and/or storage batteries. The cell was able to generate photovoltages of up to 700 mV and photocurrent of 2–6 mA/cm2 when different aqueous electrolytes were used in the dark compartment. The illuminated compartment was filled with polysulphide electrolyte and light intensity used was 70 mW/cm2. Properties such as the open-circuit voltage, the short-circuit current, the efficiency, and the effect of applied voltages in different redox couples are reported. 相似文献
109.
In a prospective, double-blind, controlled study the efficacy of clonidine was assessed in children, with respect to sedation, intubation response, and recovery. Fifty children, aged 4-12 years, undergoing general anesthesia were studied. Twenty-five children (group I) received oral diazepam) 0.2 mg/kg and another 25 children (group II) received oral clonidine 3 micrograms/kg, 90-120 minutes before induction of anesthesia. The level of sedation, hemodynamic changes to laryngoscopy and intubation, the recovery from anesthesia were noted and compared between the groups. Clonidine 3 micrograms/kg produced sedation comparable to diazepam 0.2 mg/kg (p > 0.1). There was significant (p > 0.01) attenuation of hemodynamic intubation response with clonidine. The recovery with clonidine was not delayed (p < 0.01). Clinically significant hypotension and bradycardia were not observed in any of the patients. We conclude that clonidine 3 micrograms/kg produces sedation comparable to diazepam 0.2 mg/kg and also attenuates the intubation response without increasing the incidence of complications. 相似文献
110.
Bhardwaj S. Wang W. Vattikonda R. Cao Y. Vrudhula S. 《Circuits, Devices & Systems, IET》2008,2(4):361-371
The authors present a predictive model for the negative bias temperature instability (NBTI) of PMOS under both short term and long term operation. On the basis of the reaction-diffusion mechanism, this model accurately captures the dependence of NBTI on the oxide thickness (t ox), the diffusing species (H or H 2) and other key transistor and design parameters. In addition, a closed form expression for the threshold voltage change (DeltaVth) under multiple cycle dynamic operation is derived. Model accuracy and efficiency were verified with 180, 130 and 90 nm silicon data. The impact of NBTI on the delay degradation of a ring oscillator and the various metrics of the SRAM such as its data retention voltage, read and hold margins, as well as read and write delay, is also investigated. 相似文献