180,913 research outputs found
An experimental and theoretical investigation of a wick-type solar still for water desalination
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Solar distillation using a wick-type solar still was investigated theoretically and experimentally. A tilled flat plate wick-type solar still was designed and constructed.
Charcoal cloth was used as an absorber/evaporator material and for saline water transport. A theoretical model for the performance of the wick-type solar still has been developed and analysed. It investigates the effect of various factors on the still productivity. A Fortran computer program has been developed and a finite difference technique was used to solve the main equations and to determine related parameters.
Indoor experimental testing was carried out to investigate the effect of input water flow rate and salinity on the still productivity together with the variation of the solar still efficiency with absorber temperature. The tests were conducted using the irradiance from a lamp array. Outdoor testing was carried out with and without a V-trough solar concentrator on clear days in summer and winter. Representative daily efficiencies of the still with and without the solar concentrator were about 60% and 50% respectively on clear days in summer. The solar absorptances of samples of charcoal cloth and blackened hessian cloth were determined before and after environmental exposure. The solar reflectances of samples of 3M Scotchcal Films and aluminised plastic (as potential reflecting materials for the concentrator mirrors) were investigated before and after environmental exposure and also exposure to elevated temperatures and humidities. It has been concluded that: charcoal cloth is a good material for use as an absorber/evaporator and also as a water transport medium. Increase of the input water mass flow rate leads to a reduction in the efficiency of the wick-type solar still. The still efficiency decreased linearly with Increase of salinity of the input saline water. The productivity of the still Increases linearly with absorber temperature. The best absorber-cover separation Is found to be in the range 20-25 mm. Wind speed has no significant effect (up to about 10 m/s) on the performance of a well sealed still. The transmittance of the glass cover has a strong influence on the still efficiency. Use of the solar concentrator with the inclined wick-type solar still leads to a greater fractional increase In still productivity on clear days in winter than on clear days in summer
Modeling and Design Optimization of Ultra-Thin Vapor Chambers for High Heat Flux Applications
No full textPassive phase-change thermal spreaders, such as vapor chambers have been widely employed to spread the heat from small-scale high-flux heat sources to larger areas. In this paper, a numerical model for ultrathin vapor chambers has been developed, which is suitable for reliable prediction of the operation at high heat fluxes and small scales. The effects of boiling in the wick structure on the thermal performance are modeled, and the model predictions are compared with experiments on custom-fabricated vapor chamber devices. The working fluid for the vapor chamber is water and a condenser side temperature range of 293 K–333 K is considered. The model predictions agree reasonably well with experimental measurements and reveal the input parameters to which thermal resistance and vapor chamber capillary limit are most sensitive. The vapor space in the ultrathin devices offers significant thermal and flow resistances when the vapor core thickness is in the range of 0.2 mm–0.4 mm. The performance of a 1-mm-thick vapor chamber is optimized by studying the variation of thermal resistance and total flow pressure drop as functions of the wick and vapor core thicknesses. The wick thickness is varied from 0.05 to 0.25 mm. Based on the minimization of a performance cost function comprising the device thermal resistance and flow pressure drop, it is concluded that the thinnest wick structures (0.05 mm) are optimal for applications with heat fluxes below 50 W/cm2, while a moderate wick thickness of 0.1 mm performs best at higher heat flux inputs (\u3e50 W/cm2)
7 Walde P. ,Wick R. , Fresta M. , Autopoietic self-reproduction of fatty acid vesicles J. Am. Chem. Soc. 116 (1994) 11649
No full textMarriage record of Clary, Gordon B. and Wick, Henrietta R.
No full textMarriage license for Gordon B. Clary and Henrietta R. Wick. D.T. McMullen was the officiant
Marriage record of Clary, Gorden B. and Wick, Henrietta R.
No full textMarriage license for Gorden B. Clary and Henrietta R. Wick. D.T. McMullen was the officiant
Recommended from our members
Memorial to Wick R. Miller
No full textWick R. Miller, widely respected anthropological linguist, pioneer in acquisition studies, and benefactor to our discipline, was gravely injured in a bicycle accident in Hermosillo, Sonora, on Saturday, May 7, 1994. He was flown to a hospital in Phoenix, Arizona, where he died on May 9 at the age of 62. Friends and family gathered to honor his memory in Salt Lake City on Sunday, May 15, 1994
Wick R. Miller Papers, Folder 2
No full textShoshoneThis document contains a list of sentences and their English translation
Wick R. Miller Papers, Folder 1
No full textShoshoneThis story from Indian folklore explains the origins of the Bear Danc
Wick\u27s Pet Paper; or The Possession of Pets, Dogs, and Other Beasts (Both Animal and Human) in Southern California and Surrounding Areas
No full textShoshoneIn this paper, Wick Miller analyzes Indian languages, especially vocabulary pertaining to domesticated animals. Miller claims some Indian languages use the classifying noun "pet" when referring to a domesticated animal in order to avoid implying ownership of the animal, while others do not. Miller discusses problems with pet ownership from semantic, cultural, and historic perspective
Process gg?h0??? in the Lee-Wick standard model
No full textThe process gg?h0??? is studied in the Lee-Wick extension of the standard model (LWSM) proposed by Grinstein, O’Connell, and Wise. In this model, negative norm partners for each SM field are introduced with the aim to cancel quadratic divergences in the Higgs mass. All sectors of the model relevant to gg?h0??? are diagonalized and results are commented on from the perspective of both the Lee-Wick and higher-derivative formalisms. Deviations from the SM rate for gg?h0 are found to be of the order of 15%–5% for Lee-Wick masses in the range 500–1000 GeV. Effects on the rate for h0??? are smaller, of the order of 5%–1% for Lee-Wick masses in the same range. These comparatively small changes may well provide a means of distinguishing the LWSM from other models such as universal extra dimensions where same-spin partners to standard model fields also appear. Corrections to determinations of Cabibbo-Kobayashi-Maskawa (CKM) elements |Vt(b,s,d)| are also considered and are shown to be positive, allowing the possibility of measuring a CKM element larger than unity, a characteristic signature of the ghostlike nature of the Lee-Wick fields
- …
