Field trials in four distinct agricultural soils were conducted to examine changes to total recoverable and labile soil Cd and Ni concentrations with applications of commercial phosphate fertilizers. The edible portion of wheat and potato crops grown at the field plots were analyzed for recoverable Cd and Ni. Total recoverable...
Cadmium is a common impurity in phosphatic fertilizers and may contribute to soil Cd accumulation. Changes in total and bioavailable Cd burdens to agricultural soils and the potential for plant Cd accumulation resulting from fertilizer input was investigated. Three year field studies were conducted using three dose levels of cadmium-rich,...
Solid-state amorphous materials show amazing promise in thin-film electronics. The interface-to-bulk ratio of thin films makes interfacial chemistries of these systems of utmost importance. Thin films of amorphous metals, dielectrics and semiconductors have novel chemistries that are not only based upon their elemental constituent makeup, but also based upon the...
A class of high-performance thin-film transistor (TFT) channel materials has emerged
involving oxides composed of heavy-metal cations (HMCs) with (n-1)d¹⁰ns⁰ (n≥4)
electronic configurations. This thesis is devoted to the pursuit of three topics involving
the development of these materials for TFT applications: modeling TFT currentvoltage
characteristics, an exploratory method for...
Spectroscopic ellipsometry (SE) is used to characterize amorphous and crystalline thin films of TiO2. Amorphous precursor films of TiO2 are deposited by radio frequency magnetron sputtering on fused silica and silicon substrates. Annealing the amorphous precursor films induces them to crystallize into either pure or mixed phases of the three...
The digital revolution has brought information to every corner of our daily lives. Inexpensive and flexible integrated circuits are needed for this continuing revolution. Silicon technology, the current workhorse of microelectronic industry, is far from inexpensive and flexible. Researchers are taking several different routes to achieve this goal. Amorphous silicon...
Copper sulfides (Cu[subscript x]S) are compound semiconductor materials that exhibit considerable optical and electrical properties varying significantly as a function of the composition. Copper sulfide thin films can be used in many applications, such as solar control coatings, solar cells, photothermal conversion of solar energy, electroconductive coatings, and microwave shielding...
Researchers around the world use various solution-based deposition techniques to deposit thin films with multiple layers that typically require multiple rounds of deposition. Some such techniques include successive ionic layer adsorption and reaction (SILAR), and layer-by-layer (LBL) deposition.
One of the main issues with deposition of these types of films...
The aim of this dissertation is to develop non-traditional approaches to alternating-current thin-film electroluminescent (ACTFEL) device fabrication. ACTFEL technology suffers from a lack of adequately bright and efficient primary-color phosphors and cannot presently compete in the low-cost display market. Therefore the research presented in this dissertation focuses on an exploration...
The aim of this dissertation is to develop oxide semiconductors by radio-frequency
sputtering for thin-film transistor (TFT) applications. A variety of oxide semiconductors
are used as the TFT channel layer, including indium gallium oxide (IGO), zinc tin
oxide (ZTO), and indium gallium zinc oxide (IGZO). The variety of materials used...
This dissertation outlines two approaches for improving the efficiency and reducing the cost of photovoltaic energy generation. First, the structures of known binary copper and iron compounds are used to choose the promising compositions Fe₂XS₄ (X = Si, Ge), Cu₃TaQ₄ (Q = Se, Te), and BaCuQ'F (Q' = S, Se,...
Advances in energy technologies and electronics have typically occurred through either heightened performance or cost reduction. This dissertation explores both routes through a series of fundamental material studies that may contribute to the enabling of next generation devices. Solution based syntheses and deposition of chemical products offer a low cost...
A constrained thin film desorption scheme has been experimentally tested to determine the desorption rates for water from an aqueous lithium bromide mixture through a confining membrane. Variable conditions include the inlet concentration, pressure differential across the membrane, and channel height. Desorption takes place in a channel created between two...
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1.2 Thinfilm desorption process showing both the thermal and concentration
gradients expected
The primary focus of this thesis involves modeling and development of p-type thin-film transistors (p-TFTs), moving towards the realization of a filly transparent thin-film transistor (TTFT). The modeling portion of this thesis emphasizes the development of physics-based TFT models, specifically focusing on the elucidation of non-ideal current-voltage characteristic behavior. A...
CuGaSe₂/CuInSe₂ tandem junction solar cell is currently being pursued to be a low cost and high efficiency renewable energy source. A reported theoretical efficiency of 33.9% solar cells has been the motivation to fabricate CuGaSe₂ films in a simple and low cost method. Electrodeposition is a potentially suitable method to...
The objective of this dissertation is to introduce low-cost processing methods for the fabrication of ZnO transparent thin-film transistors (TTFTs). A novel method for depositing ZnO body layers via spin-coating of a zinc nitrate-based spin solution is presented. The processing conditions of spin-coated ZnO are optimized to produce continuous and...
Current leading thin-film solar cell technologies, i.e., cadmium telluride (CdTe) and copper indium gallium diselenide (CIGS), employ elements which are either toxic (Cd), or rare and/or expensive (In, Te, Ga, and Cd). The aim of this thesis is to investigate new, abundant, non-toxic p-type semiconductors for potential solar absorber application....
The focus of this thesis involves development of highly transparent, n-channel, accumulation- mode thin-film transistors employing a zinc tin oxide (ZTO) channel layer. ZTO-based transparent thin-film transistors (TTFTs) show improved device performance compared to ZnO-based TTFTs. An estimated peak effective mobility for these devices as high as ~100 cm² V⁻¹sec⁻¹...
The trend towards higher resolution, faster refresh rate active-matrix liquid-crystal displays (AMLCDs) as well as the emergence of active-matrix organic light-emitting diode (AMOLED) displays is driving the demand for amorphous oxide semiconductor thin-film transistors (AOS TFTs) with higher mobility. A physics-based model for carrier transport in an amorphous semiconductor is...
The linear theory of double diffusive interleaving is extended to take account of baroclinic effects. This study goes beyond previous studies by including the possibility of modes with nonzero tilt in the alongfront direction, which allows for advection by the baroclinic frontal flow. This requires that the stability equations be...
Piezoelectric materials have been widely used in electromechanical actuators, sensors, and ultrasonic transducers. Among these materials, lead zirconate titanate Pb(Zr[subscript 1‐x]Ti[subscript x])O₃ (PZT) has been primarily investigated due to its excellent piezoelectric properties. However, environmental concerns due to the toxicity of PbO have led to investigations into alternative materials systems....
Polylactic acid (PLA), a renewable material, is used widely in a variety of commercial and specialty applications. However, certain limitations such as high temperature stability and brittleness limit its applicability. This problem is addressed by reinforcing PLA with a variety of materials but the process gives rise to different issues...
A scalable synthesis of the "flat" tridecameric inorganic cluster [Al₁₃(μ₃-OH)₆(μ-OH)₁₈(H₂O)₂₄]¹⁵⁺ has been realized by treating an aqueous aluminum nitrate solution with zinc-metal powder at room temperature. Single crystals and polycrystalline samples are readily obtained in yields exceeding 55% relative to the starting reagent Al(NO₃)₃. Products have been characterized by X-ray...
An experimental investigation of the thermohaline, diffusive interface between convecting layers, with heat fluxes more similar to natural fluxes than in previous studies, shows that the formula suggested by Huppert (1971) for the dependence of heat flux on interface stability cannot be extrapolated to stability numbers higher than seven and...
A long-standing challenge to the widespread application of complex oxide thin films is the stable and robust integration of noble metal electrodes, such as platinum, which remains the optimal choice for numerous applications. By considering both work of adhesion and stability against chemical diffusion, it is demonstrated that the use...
The development of solution-based methods for deposition of different thin film material is presented as an alternative to high cost vacuum-based methods. For certain materials, vacuum techniques are unsuitable for processing. Additionally, vacuum-based processes present high capital costs associated with equipment, and slow processing times. Atmospheric pressure solution based techniques...
CuInGaSe₂ (CIGS), a promising thin film solar cell material, has gained lots of
attention in decades due to its high energy conversion efficiency and potential lower
manufacture cost over conventional Si solar cells. As a cheaper processing method
compared to vacuum-based techniques, solution-based deposition has been
successfully applied to fabricate...
Pb(Zr₀.₅₂Ti₀.₄₈)O₃ (PZT) thin films are of interest for their large dielectric permittivity, ferroelectric, and piezoelectric properties. The material has been widely studied for use in high frequency transducers, multi-layered capacitors, and ferroelectric random access memory. Copper foils are an inexpensive, flexible substrate with a low resistivity which makes them ideal...
The linear stability of a double-diffusively stratified, inflectional shear flow is investigated. Double-diffusive stratification has little effect on shear instability except when the density ratio R[subscript]ρ is close to unity. Double-diffusive instabilities have significant growth rates and can represent the fastest-growing mode even in the presence of inflectionally unstable shear...
The electrical stability of amorphous indium-gallium-zinc oxide (a-IGZO) thinfilmtransistors (TFTs) is investigated for flat-panel display applications. Althoughproducts incorporating a-IGZO TFT backplanes are already commercially available,e.g., iMac with 5K retina display, technical challenges need to be addressed for nextgenerationapplications, e.g., active-matrix organic light-emitting diode displays.Device stability is one crucial issue. The...
The behavior of the thin liquid film formed between a bubble and hydrophobic membrane is of high interest in applications where separating two-phase mixtures is beneficial. One such application is in-situ vapor extraction heat sinks. In these systems, high heat transfer rates are accomplished by taking advantage of the high...
Structure-specific synthesis processes are of key importance to the growth of polymorphic functional compounds such as TiO₂, where material properties strongly depend on structure as well as chemistry. The robust growth of the brookite polymorph of TiO₂, a promising photocatalyst, has been difficult in both powder and thin-film forms due...
Metal-oxo clusters are discrete, soluble pieces of bulk metal oxide. Cluster size, monodispersity, and chemical properties allow for potential use as solution-based precursors for functional metal oxide films. Classical monoalkyltin-oxo clusters are either charge neutral or stabilized by anions. The structure of Cs₄.₅H₂.₅[(BuSn)₃(α-SiW₉O₃₇)]*2H₂O enables its use in established ion exchange...
We have measured sweep-rate-dependent magnetization hysteresis curves of thin-film Bi₂Sr₂CaCu₂O[subscript 8+δ] using a Hall probe magnetometer in an unconventional geometry. We find a structure in the response well below the three-dimensional to two-dimensional crossover field. The observed strong enhancement of the perpendicular field component’s creep rate in the presence of...
Thin films of wide band-gap semiconductors are deposited by the pulsed laser deposition method. Optimal deposition parameters for the individual compounds are reported. A family of p-type BaCuQF (Q = S, Se, Te) ceramics with a layered crystalline structure is investigated for active and passive device applications.
Epitaxial films of...
Tests of a formula derived for the cutoff wave number of vertical temperature gradient spectra, using
data taken in the upper layers of the North Pacific, show encouraging results. To derive this formula, the
cutoff wave number is assumed to be the Batchelor wave number, with kinetic energy dissipation calculated...
To become a competitor for fossil fuels such as coal, solar installations will need to be produced and installed at a price equal to or below grid parity. This price can be approached by either reducing the overall system cost or increasing system efficiency. The focus of this paper is...
An experimental study of absorption of ammonia into a constrained thin film of ammonia-water solution is presented. A large aspect ratio microchannel with one of its walls formed by a porous material is used to constrain the thickness of the liquid film. Experiments were performed at a pressure of 1,...
Protection of the quality and integrity of food supplies is of global concern. Crops can accumulate non-nutritive and sometimes toxic metals and metalloids. Accumulated metals/metalloids can come in part, from fertilizers, which may contain variable levels of non-nutritive metals or metalloids such as arsenic (As), cadmium (Cd), lead (Pb), nickel...
Continuous liquid-liquid two-phase separation is needed in microfluidic devices. Due to the small characteristic lengths of microreactors, phenomena such as mass transport via molecular diffusion occur within seconds. Typically, discrete slugs of an extract are created within microchannels for high specific interfacial area to achieve intensified mass transfer. A challenge...
The motivation for undertaking this research was to increase the understanding of processing colloidal semiconductor nanocrystals and thin films metallic glasses to enable their wider application in future devices. This research covered two unique materials, lead selenide (PbSe) nanocrystals and thin film metallic glass alloy of zirconium copper aluminum nickel...
Field trials in four distinct agricultural soils were conducted to examine changes to total recoverable and labile soil Cd and Ni concentrations with applications of commercial phosphate fertilizers. The edible portion of wheat and potato crops grown at the field plots were analyzed for recoverable Cd and Ni. Total recoverable...
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diffusivegradientsinthinfilms (DGT), a
passive sampling device reported to estimate the plant
Field trials in four distinct agricultural soils were conducted to examine changes to total recoverable and labile soil Cd and Ni concentrations with applications of commercial phosphate fertilizers. The edible portion of wheat and potato crops grown at the field plots were analyzed for recoverable Cd and Ni. Total recoverable...
Chemistry of preparing dense film from solution deposition is explored with several cases in this thesis. Surface dense structure, conversion at melting point, and ion exchange in aqueous solution are the main topics covered here for the thin films of aluminum oxide phosphate and tin dioxide. Thin film density, optical...
The phytohormones auxin and cytokinin control plant development through a complex network of interactions which include synergistic, additive, and opposite effects whose mechanisms are unknown. The auxin-insensitive diageotropica (dgt) mutant provided a tool to dissect the relationship between auxin- and cytokinin-induced responses in tomato. Morphological, physiological, and molecular data support...
The ternary system (Bi₀.₅Na₀.₅)TiO₃-(Bi₀.₅K₀.₅)TiO₃-Bi(Mg₀.₅Ti₀.₅)O₃ (BNT-BKT-BMgT) was explored along the [75-(x 2) ]Bi₀.₅Na₀.₅TiO₃ - [25-(x 2)]Bi₀.₅K₀.₅TiO₃ - [x]Bi(Mg₀.₅Ti₀.₅)O₃ composition line. Thin films were fabricated using chelated mixing route solutions spin cast onto platinized silicon substrates. Processing parameters such as: excess cation molar%, solution molality, and crystallization temperatures, for composition where x=0,...
Cadmium is a common impurity in phosphatic fertilizers and may contribute to soil Cd accumulation. Changes in total and bioavailable Cd burdens to agricultural soils and the potential for plant Cd accumulation resulting from fertilizer input was investigated. Three year field studies were conducted using three dose levels of cadmium-rich,...
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.
Keywords
Cadmium; Bioavailability; DiffusiveGradientsinThinFilms (DGT); Field
experiments; Plant
Cadmium is a common impurity in phosphatic fertilizers and may contribute to soil Cd accumulation. Changes in total and bioavailable Cd burdens to agricultural soils and the potential for plant Cd accumulation resulting from fertilizer input was investigated. Three year field studies were conducted using three dose levels of cadmium-rich,...
Recently, models for the onshore migration of nearshore sandbars were improved by including an empirical acceleration term in the sediment transport formulation (Hoefel and Elgar, 2003). Here, field observations of the fluid-sediment interface suggest that the success of this empirical parameter may result from unsteady forcing of sediment beds by...
In this study the impact of episodic events on levels of bioavailable trace metals Zn,
Cu, Cr, Cd, Pb, and As (III) were determined for the lower Willamette River in Oregon.
In addition, a comparison among three alternative methods for estuary sampling was
conducted. Potential adverse human health risk associated...
Development of efficient methods for the destruction of solid wastes and recovery of valuable resources is needed to support long-duration manned missions in space. In particular, these technologies are required for deployment in hypogravity and microgravity environments, such as at the lunar or Martian surfaces. Gradient Magnetically Assisted Fluidized Bed...
Momentum transfer in an annular duct with upward gas-Iiquid
flow was studied under the condition that the liquid flowed as a film
only on the inner core of the annulus, the outer wall remaining dry.
Previous workers have studied climbing and falling liquid
films in tubes or on vertical planes....
The purpose of this study is to synthesize and characterize the nanoporous structures that can be obtained by the anodization of thin film aluminum sputter deposited on a silicon wafer substrate. This study also investigated the application of nanoporous alumina to fabricate nanorod arrays by using preceramic polymers. Although there...
An experimental and numerical study of absorption of ammonia vapor bubbles into a constrained thin film of ammonia-water solution is presented in the context of a potential reduction in size of a heat-actuated heat pump component. A large-aspect-ratio channel with a depth of 600 µm restricts the thickness of the...
This report is one of a series issued in cooperation with the ANC-17 Panel on Plastics for Flight Vehicles of the Departments of the Air Force, Navy, and Commerce.
Equipment and procedures for the rapid measurement of the water vapor
permeability of polymer films and food coatings has been evaluated. The
method uses an electronic sensor to measure the concentration increase in
water vapor diffusing through a film into a chamber of known volume. Air of
known humidity is...
The use of edible coatings in combination with antimicrobial
agents enhances the microbial stability of foods. In this study we
evaluated the potassium sorbate and sorbic acid permeability of an
edible methylcellulose (MC) - palmitic acid (PA) film with a MC:PA
ratio of 3:1.
Permeability cell measurements were used to...
This paper describes a study of two-phase gas-liquid vertical
annular climbing film flow. Using a high speed Fastax movie camera,
motion was slowed sufficiently to facilitate detailed analysis of the
climbing film structure, based on single frame projections. The
dynamic characteristics of the liquid film could likewise be obtained,
though...
Soil food webs process the majority of terrestrial carbon, and influence overall ecosystem function. A primary distinction among soil food webs is based on fungal versus bacterial pathways of decomposition; these lead to fundamentally different soil function, and are expected to differ in dominance between meadows and forests. This assumption...
This investigation focuses on gaining a better understanding of the complex relationship between melt generation, source variability and mid-ocean ridge morphology. The approach adopted here uses a variety of geochemical techniques to evaluate the ability of 'global' models to predict regional scale geochemical variability associated with axial depth and axial...
Momentum transfer in climbing-film flow in an annular duct was
investigated. Air and various liquids, with a wide range of viscosities
and surface tensions, were investigated. The two phases flowed co-currently
upward, the liquid climbing as a thin film on the inner wail
while the outer wall remained dry.
The...
Solute transport models in karst groundwater must consider variable and complex flow regimes. Within fissures less than 2 mm in aperture, during unsaturated flow events, seeping flow may flow as films or under capillary tension as a capillary rivulet. This project focuses on exploring the mass transport characteristics of seeping...
Design and preliminarily characterization of two thermally-actuated pumps is presented
in this thesis. The unique feature of both pumps is the presence of periodic asymmetrical
structures on the channel walls. Two heat transfer effects are used with surface
asymmetry to generate forces that drive the fluid in a preferential direction...
A constant temperature anemometer, utilizing quartz coated hot
film probes, was used to measure velocities from .1 to 5 cm/sec.
The effects on anemometer performance due to time, reimmersion,
and metallic sensor coatings were examinated by repeated calibrations
of the probes. Contrary to previous published results, calibration
change due to...
In this work, a multicomponent lattice Boltzmann model is developed for the simulation of multiphase mixing, reactions, and separations processes. This model is unique in that diffusive mass transfer of a component in the model is driven by gradients of chemical potential. This fundamentally correct description of diffusion accurately captures...
The research presented herein focuses on electrical assessment of oxide thin films as insulators. The current density-electric field (J-E) characteristics of four insulators of dramatically different electrical quality are assessed in terms of their operative electronic conduction mechanisms. Conduction in the two high-quality insulators is dominated by Ohmic conduction and...
Edible coatings controlling preservative migration from
surface to food bulk could inhibit surface microbial growth
which is often the main cause of spoilage for many food
products. In this project we focused our attention upon
methylcellulose, hydroxypropyl methylcellulose, and chitosan as
the structural component for such edible films. These films...
Submillimeter depth distributions of total dissolved inorganic carbon (DIC) were derived from pH and PCO2 profiles measured with microelectrodes in an organic-rich, laboratory-maintained sediment. The DTC profiles were used to calculate diffusive fluxes of DIC across the sediment-water interface. In two experiments, the calculated diffusive fluxes fell within ±50% of...
The kinetics of physical and chemical processes controlling the precipitation of iron oxide minerals in unsaturated media were investigated in this study. The characteristic morphology, mineralogy, and chemistry of iron oxides were also explored. Laboratory column experiments using fine and coarse grades of silica sand were conducted to compare the...
The results of an investigation into carrier dynamics in several novel functionalized and solution-processable pentacene and anthradithiophene derivatives are reported. Measurements were made of real-time photoresponse of polycrystalline thin films of these materials to ultrafast laser pulses, on picosecond to microsecond time-scales, as well as measurements of dark current and...
The search for and discovery of early archaeological sites is an inherently geoarchaeological problem. Archaeological sites of late Pleistocene-age are known to be located in the Intermountain West, however, the record of these early sites remains limited to only a few examples. In the lower Salmon River canyon (LSRC), the...
The work in this thesis involves the development of specimen preparation techniques for the observation with an electron microscope of alpha
particle tracks in cellulose nitrate plastic.
Both direct observation
using thin films and replica production techniques were investigated.
Direct observation of the alpha tracks was accomplished by cutting
thin...
Microchannel process technology (MPT) offers several advantages to the field of nanomanufacturing: 1) improved process control over very short time intervals owing to shorter diffusional distances; and 2) reduced reactor size due to high surface area to volume ratios and enhanced heat and mass transfer. The objective of this thesis...
The kinetics of laser-induced, liquid-mediated crystallization of amorphousGe thin films were studied using multi-frame dynamic transmission electron microscopy (DTEM), a nanosecond-scale photo-emission transmission electron microscopy technique. In these experiments, high temperature gradients are established in thin amorphousGe films with a 12-ns laser pulse with a Gaussian spatial profile. The hottest...
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electron microscopy technique. In these experiments, high temperature
gradients are established inthin
The kinetics of laser-induced, liquid-mediated crystallization of amorphousGe thin films were studied using multi-frame dynamic transmission electron microscopy (DTEM), a nanosecond-scale photo-emission transmission electron microscopy technique. In these experiments, high temperature gradients are established in thin amorphousGe films with a 12-ns laser pulse with a Gaussian spatial profile. The hottest...
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the grains of the thinfilm make it
difficult to discern individual grains, but an orientation map (d
The kinetics of laser-induced, liquid-mediated crystallization of amorphousGe thin films were studied using multi-frame dynamic transmission electron microscopy (DTEM), a nanosecond-scale photo-emission transmission electron microscopy technique. In these experiments, high temperature gradients are established in thin amorphousGe films with a 12-ns laser pulse with a Gaussian spatial profile. The hottest...
The research presented in this thesis is a continuation of collaboration between Oregon State University and Auburn University studying the feasibility of passively pumping liquid during boiling in a preferential direction using meso-scaled asymmetric surface patterns. Such a passive phase-change mechanism has great potential for thermal management in spacecraft and...
Sintering of nanoparticles to create films and patterns of functional materials is emerging as a key manufacturing process in applications like flexible electronics, solar cells and thin-film devices. Further, there is the emerging potential to use nanoparticle sintering to perform additive manufacturing as well. While the effect of nanoparticle size...
At the smallest length scales, conductivity measurements include a contribution from salinity fluctuations in
the inertial–convective and viscous–diffusive ranges of the turbulent scalar variance spectrum. Interpreting these
measurements is complicated because conductivity is a compound quantity of both temperature and salinity.
Accurate estimates of the dissipation rate of salinity variance...
The chemistry of hafnium oxide based and materials are described in the context of ion exchange and lithography. HafSOx, represented by the composition HfO₂₋[subscript x](SO₄)x, is described to possess a significant capacity towards ion exchange in acidic and basic solutions, enabling films of HafSOx to be cleanly and readily be...
It is known that soil biota affects water dynamics through various complex mechanisms. The impact on retention by soil biota are due to a combination of changes to pore geometry, pore clogging by biofilms, biofilms that serve to connect thin water films across many pores as the soil dries, and...
The understanding of critical heat flux is crucial for the safety of nuclear reactors. To this end, many studies have been carried out to understand various aspects of the boiling crisis phenomenon. Power transient critical heat flux trigger mechanisms is a small category that is relatively under-studied and not well...
Direct determination of the irreversible turbulent flux of salinity in the ocean has not been possible because of the complexity of measuring salinity on the smallest scales over which it mixes. Presented is an analysis of turbulent salinity microstructure from measurements using a combined fast-conductivity/temperature probe on a slowly falling...
The various solution-based processes, spin coating, inkjet printing, microreactor assisted nanoparticle deposition (MANDTM) and spin-successive ionic layer absorption and reaction (Spin-SILAR) were used to demonstrate thin film electronics and anti-reflective coatings. Several aspects of thin film transistors (TFTs) were tested including a range of temperatures, annealing atmosphere, and deposition methods....
Characterization of local boiling trends, in addition to the typically reported area-averaged trends, is essential for the robust design and implementation of phase change technologies to sensitive heat transfer applications such as electronics cooling. This paper compares local and area-averaged boiling curves during a phase change process using non-intrusive quantitative...
Engineered capillary barriers typically consist of two layers of granular materials designed so that the contrast in sediment hydrologic properties and sloping interface retains infiltrating water in the upper layer. We report here on the results of two bench-top capillary barrier experiments, and associated modeling. These experiments were conducted to...
The upward flux of heat from the subsurface core of Warm Deep Water
(WDW) to the perennially ice-covered sea surface over the continental slope in the
western Weddell Sea is estimated using data obtained during February-June 1992
from a drifting ice station. Through the permanent pycnocline the diapycnal heat
flux...
Evaporation synergy is the phenomenon in which two porous medium textures that share a common vertical boundary experience a higher cumulative evaporation than either homogeneous texture can produce. Studies that have been conducted to date address this phenomenon in relatively fine and coarse sands but not in finer textured soils...
A model for the spatial and temporal evolution of the gray sericitic (GS) and sericite with remnant biotite (SBr) hydrothermal alteration selvages within the Butte Quartz Monzonite (BQM) of the porphyry copper deposit at Butte, Montana, is presented. The model provides a mathematical description for the location and advance of...
The plant hormone auxin regulates many aspects of plant growth and
development. At the cellular level, auxin can stimulate cell division, cell elongation, and
cell differentiation. Little is known about the molecular mechanisms that mediate auxin
action at this level, although changes in gene expression have been implicated in each...
