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The relation between the electrical property and the material microstructure of InSb grown on Si utilizing electron beam evaporation technology has been investigated. The improvement of the InSb electrical property with controlling annealing environment after post annealing is demonstrated. The crystal structure of InSb thin films were characterized with X-ray diffraction (XRD) and the surface morphology was examined by scanning electron microscope (SEM). The composition of InSb films was analyzed by electron probe microscope analysis (EPMA) and the mobility of InSb films were measured by Hall measurement. Finally, the grain size and texture of InSb films microstructure were studied by transmission electron microscope (TEM). The films were grown with different In/Sb flux ratio by controlling electron energy during electron evaporation. The results show that the poly-InSb films were formed due to large lattice difference between Si and InSb . The InSb films which had higher In concentration behave higher mobility. The highest mobility of the as-grown film is around 12000(cm2/Vs). The mobility of InSb can be improved to 26000 (cm2/Vs) by added extra Sb source annealed at 500¢J for 5 hours in an sealed ampoule. The extra Sb which dissolved with the existed In droplet in the film and adjust the composition ratio of In/Sb closing to 1:1. Besides, the post-annealing process provides the InSb film to gain much better texture. Both these two factors contribute to improve the electrical property of InSb films.

Loop heat pipes seem a promising approach for application in modern technologies where such thermal devices as cooling fans and radiators cannot satisfy overall requirements. Even though a loop heat pipe has a big potential to remove the thermal energy from a high heat flux source, the heat removal performance of heat pipes cannot be predicted well since a first principles of evaporation has not been established. An evaporation model based on statistical rate theory has been recently suggested by Ward and developed for a single pore by Oinuma. A loop heat pipe with coherent pore wick structure has been proposed as a design model. To limit product development risk and to enhance performance assurance, design model features and performance parameters have been carefully reviewed during the concept development phase and have been deliberately selected so as to be well-founded on the limited existing loop heat pipe knowledge base. A first principles evaporation model has been applied for evaporator geometry optimization. A number of iteration calculations have been performed to satisfy design and operating limitations. A set of recommendations for design optimization has been formulated. An optimal model has been found and proposed for manufacture and experimental investigation.

Colloidal suspensions of disk-like particles have been of interest in both colloidal and liquid crystal studies because they exhibit unique liquid crystalline phases different from those of rod-like molecules. Disk-like particles, such as asphaltenes in heavy oil industry, clay particles in agriculture, and red blood cells in biology, are of great interest in a variety of industries and scientific areas. However, to fabricate monodisperse microdisks, uniform in structure or composition with precise control of particle size and shape has not yet succeeded. In this thesis, we show an experimental strategy of using microfluidic technique to fabricate homogeneous α-eicosene microemulsions with chloroform in an aqueous solution of sodium dedecyl sulfate (SDS). The monodisperse chloroform emulsions, generated by the glass-based microfluidic devices, ensure the precise control on microdisk particle size and shape. A systematic investigation was performed to study the relation between the resulted microdisk size and the initial concentration of α-eicosene in chloroform before evaporation. The smectic liquid crystalline phase inside the wax particles controls the coin-like disk shape below the melting temperature of wax’s rotator phase. The kinetics of the disk formation is observed using a polarized light microscope. Dynamic light scattering is used to characterize the Brownian motion of the microdisks, and the rotational diffusion is estimated from the image sequences taken by the charge-coupled device (CCD) camera. Effort has been put into collecting a large quantity of microdisks to investigate the discotic liquid crystalline phases, which can be readily probed by light scattering and microscope. In comparison, X-ray and neutron have to be used for the atomic liquid crystalline phase investigation.

In this study, the AZO thin films were deposited with various manufacturing conditions, such as working pressure of oxygen and substrate temperature, by e-beam evaporation. The microstructure of the AZO film was observed by SEM and AFM. Sheet resistance was measured using four-point probe method. Optical transmittance was measured in the visible range by UV spectrophotometer. Finally, AZO transparent film was used as a substitute for ITO to fabricate the radiation-resistant glasses. The optimum parameters for depositing AZO films are glass substrates of 80¢J and working pressure of 1¡Ñ10-4 Torr. The film resistance is 9.2¡Ñ10-4 £[-cm with a film thickness of 60 nm. The refractive index was measured to be 2.05 at a wavelength of 510 nm. The optical transmittance of the prepared films was above 83 % in the visible range. The manufacturing conditions for depositing AZO multilayer coatings are working pressure of 5.0¡Ñ10-5 Torr, ion gun working pressure of 6.0¡Ñ10-5 Torr, voltage of 6.2 V, oxygen gas flow rate of 36 sccm and glass substrates of 80¢J. The optical transmittance of the glass was above 94 % in the visible range.

In some configurations of compact, biofilm based photobioreactors, algae grow on a porous substrate that acts as the support system for the cells providing them with the necessary water and nutrients as well as carrying away their secreted products. The flow in these porous media can be driven by evaporation, mimicking the function of a synthetic leaf. The surface properties of the porous medium as well as the presence of a second immiscible phase in the fluid transported can significantly alter the transport capability and evaporative performance of the porous medium. The focus of this study is to investigate these effects through an experimental study. A dilute, 1% emulsion of lauric acid (chemical formula: C₁₂H₂₄O₂) in water was prepared using Tween® 80 surfactant. Evaporation driven flow of deionized water and the emulsion through two porous media, a hydrophilic glass fiber membrane and a less hydrophilic poly(vinylidene) fluoride (PVDF) membrane were studied. Experiments were conducted to determine the effect of porous medium and fluid properties on the rate of evaporation. The parameters investigated were the hydrophilicity of the porous medium and the area of the porous medium available for evaporation for both water and emulsion. During the experiment, the mass flow rate of the fluid as well as the temperature and the relative humidity of the ambient air were monitored. The results showed that for dilute emulsions, the rate of evaporation observed was the same as that for water and was dictated by the governing laws of convection applicable to the situation based on the geometry of the setup and the ambient conditions. The response of the porous medium to flow of dilute emulsion showed that the highly hydrophilic glass fiber porous medium rejected any accumulation of the oil phase in the pores, and ejected it out, whereas the lesser hydrophilic PVDF porous medium allowed the pores to be clogged by the oil phase, resulting in change in the properties of the medium. However, the dependence of this observation solely on surface properties of the medium cannot be ascertained as the glass fiber medium had a larger pore diameter than the PVDF medium, and this factor could be of effect. The relative humidity of ambient air affected the rate of evaporation, which implied that the flow was limited by evaporation rather than by the viscous losses in the porous medium. The response of change in rate of evaporation to change in relative humidity showed a high time lag. Also, it was seen that there was a maximum area over which evaporation occurred which was dictated by the capillary pressure generated by the porous medium and the viscous losses for the fluid flow through the medium. Any excess area available for evaporation did not have any effect on the rate of evaporation. Electrospinning, as a simple and effective process for generating fibrous porous media was presented and a sample porous medium was prepared using this method. A parametric analysis of the effect of the potential difference applied between the syringe tip and the collector electrode, and the distance between the tip and the collector on the diameter of fibers produced, was performed. / text

Three goals of this research were: 1) to develop a field-scale research facility that could be used for conducting a variety of soil water experiments in both deep (greater than 2 meters) and near-surface soils where the soil water balance could be accurately determined; 2) to develop a transient experimental technique for calibrating time domain reflectometry (TDR) probes; and 3) to study the use of vertically-installed TDR probes for measuring near-surface soil water movement in a field setting, and to compare these measurements with those made by the weighing lysimeter. The weighing lysimeter facility consists of two lysimeter tanks, 4.0 m deep and 2.5 m in diameter, which rest atop a scale with a resolution of ±200 g, equivalent to ±0.04 mm of water on the surface. Data collection is completely automated with a data logger and personal computer. Both lysimeters are instrumented with TDR probes, tensiometers, and pore water solution samplers; thermocouples are installed in one lysimeter for measuring temperature. The TDR probes were calibrated using a transient method known as upward infiltration. The method is rapid, allows the soil to remain unchanged during the experiment, and provides many data points. The upward infiltration method was tested using two different length probes in soils of three textures. Results show that the upward infiltration method is stable, repeatable, and provides accurate dielectric constants and calibration curves. Four, vertically-installed TDR probes of different lengths (200, 400, 600, and 800 mm) were placed in the lysimeter at ground surface to measure water added and water lost during a one-month period in the presence of daily irrigated turfgrass. The purpose of this study was to compare changes in soil water storage as measured by the TDR system, against measurements made using the weighing lysimeter. The TDR probes detected diurnal changes in water content due to irrigation and evapotranspiration, even when these amounts changed slightly from day to day. The TDR probes underestimated the measurements of both water added and water loss, as confirmed using measurements from the weighing lysimeter. The presence of a 47-mm thick biomass above the TDR waveguides retained water that otherwise would have percolated the soil surface into the measurement domain of the probes. Addition and loss of water in the biomass were recorded by the lysimeter, but not by the TDR probes, thus explaining the underestimation. Modeling of near-surface water movement with the HYDRUS model showed very similar water movement behavior as measured by the TDR probes. This confirms our hypothesis that TDR would a useful tool for measuring diurnal changes in water content for irrigation scheduling.

Project Completion Report, OWRT Project No. A-091-ARIZ / Agreement No. 14-34-0001-8003 / Project Dates: October 1978 - September 1979 / Acknowledgement: The work upon which this report is based was supported by funds provided by the United States Department of the Interior, Office of Water Research and Technology, as authorized under the Water Resources Research Act of 1978. / This report contains the results of a one year study to develop improved methods of evaporation control using wax impregnated foam. The foam used was expanded polystyrene and the wax used was paraffin with a 140° F melting point. The report tells of a pressure chamber that was used to wax impregnate sheets of expanded polystyrene. Based on tests made in the laboratory the pressure chamber was modified into a vacuum chamber. Problems were encountered getting the interior of the sheets impregnated using a vacuum. There was no way this problem could have been predicted based on the smaller laboratory models. The pressure method, however, was successfully used to impregnate up to 3 -inch thick sheets of expanded polystyrene. During the project it was found that the paraffin impregnated rafts worked very well until high temperatures, 100° F plus, are encountered Under dusty conditions. The heat causes the surface of the wax to get tacky, the dust darkens the otherwise white surface, which in turn captures more heat, and then more dust, etc. The high surface temperature caused an accelerated weathering of the material. Because of this, waxes with higher melting points were tried. Additional work is needed in this area as no satisfactory combinations were found. Two polyethylene copolymers with a melting point close to the 190° F destruction point of the expanded polystyrene were tested. This wax was too viscous for impregnation but provided a hard surface coating when the previously wax impregnated expanded polystyrene is dipped into the molten polyethylene wax. This dipping might be the best method for surface protection at low cost but additional testing is needed before trying the material out on a large scale. Progress was made in the development of wax impregnated lightweight concrete rafts. The wax impregnation of the lightweight raft solves the vapor penetration problem. This type of raft was found to resist removal by wind and weathered very well in the one year of testing. Connecting rafts with strips of sheet metal bonded to the expanded polystyrene was done on a small scale, and needs to be field tested. The PVC pipe C clamps work well on partially submerged rafts but need to be lengthened to interconnect wax impregnated rafts. Square wax impregnated rafts lx1 ft in size did not stay on a small test pond in high wind. Circles are presently being tried but additional testing is needed in this area before their reliability is known.

Research Project Technical Completion Report (A-109-Ariz.) For: United States Department of the Interior, Project Dates: 1981-1983, September 1, 1983. / The Research on which this project is based was financed in part by the U.S. Department of the Interior, as authorized by the Water Research and Development Act of 1978 (P.L. 95-467) / A liquid level interferometer has been built to measure changes in water level to an accuracy of /8. A novel magnetic suspension is used to position the floating retroreflector of a laser interferometer. Direction sensing is achieved by dual optical channels phased near quadrature by means of an absorbing beamsplitter. The interferometer (laser) has been used to measure very accurately the drop in water level of a lined reservoir. The drop in water level thus provides a precise method of measuring evaporation. It was found that this drop in water level essentially ceased when the relative humidity approached very closely or equaled 100 percent during early morning calm periods. This provides a method of determination of seepage loss. In an unlined reservoir during calm periods when the relative humidity is 100 percent any remaining drop in water level is due to seepage. The laser can measure this rate.

A mathematical model is developed to describe the micro/nano-scale fluid flow and heat/mass transfer phenomena in an evaporating extended meniscus, focusing on the transition film region under nonisothermal interfacial conditions. The model incorporates thermocapillary stresses at the liquid-vapor interface, a slip boundary condition on the solid wall, polarity contributions to the working fluid field, and binary mixture evaporation. The analytical results show that the adsorbed film thickness and the thin film length decrease with increasing superheat by the thermocapillary stresses, which influences detrimentally the evaporation process by degrading the wettability of the evaporating liquid film. In contrast, the slip effect and the binary mixture enhance the stability of thin film evaporation. The slip effect at the wall makes the liquid in the transition region flow with smaller flow resistance and thus the length of the transition region increases. In addition, the total evaporative heat flow rate increases due to the slip boundary condition. The mixture of pentane and decane increases the length of the thin film by counteracting the thermocapillary stress, which enhances the stability of the thin film evaporation. The polarity effect of water significantly elongates the thin film length due to the strong adhesion force of intermolecular interaction. The strong interaction force restrains the liquid from evaporation for a polar liquid compared to a non-polar liquid. In the experimental part, laser induced fluorescence (LIF) thermometry has been used to measure the microscale temperature field of a heated capillary tube with a 1 mm by 1 mm square cross section. For the temperature measurement, the calibration curve between the temperature and the fluorescent intensity ratio of Rhodamine-B and Rhodamine-110 has been successfully obtained. The fluorescent intensity ratio provides microscale spatial resolution and good temperature dependency without any possible bias error caused by illuminating light and background noise usually encountered in conventional LIF techniques. For the validation of the calibration curve obtained, thermally stratified fields established inside a glass cuvette of 10 mm width were measured. The measurement result showed a good agreement with the linear prediction. The temperature measurement in a 1 mm capillary tube could provide the feasible method of temperature measurement for the thin film region in the future.