The Kittlitz's murrelet (Brachyramphus brevirostris) is a rare member of the seabird family Alcidae that breeds in coastal areas of Alaska and Beringian Russia. The species belongs to the genus Brachyramphus, an unusual seabird taxon in which all three extant species nest non-colonially, situating their nests up to 75 km...
Transparent conductive oxides (TCOs), primarily indium doped tin oxide, have been widely used in numerous fields since decades ago, such as solar cells, displays, OLEDs and ‘smart windows’ etc. Owing to the scarcity of indium, there is a great demand for new alternative materials. Metal/insulator/metal (MIM) diodes are a critical...
Level of aspiration plays a part in achievement motivation which
supports teaching/learning in motor performances. In the past,
females reported poorer ability in performances, set lower levels of
aspiration, and had lesser achievement motives than males (Crandall,
1969; Stein & Bailey, 1973; Sumner & Johnson, 1949). Some researchers
found there...
This thesis will discuss two critical components of a digital system -- domino logic styles and flip-flops. In today's microprocessors, both domino logic and flip-flops are essential to high-performance and low-power design. Two new domino logic styles are presented and analyzed, Double Edge Triggered (DET) and Double Data Rate (DDR)...
Current observations were obtained at three locations forming
a cross section along 70°34'W longitude in Long Island Sound. Fifteen
days of data were selected from each series so that nearly
simultaneous observations were used in the analysis.
Elementary statistics were computed for the data prior to
performing a least squares...
This thesis describes the transport properties observed in thermally treated graphite oxide (GO), which holds promise as an economical route to obtaining graphene. Graphene is a material consisting of a single atomic plane of carbon atoms and was first isolated as recently as 2004. Several isolation techniques have been investigated,...
The US military is evaluating the capabilities of emerging technologies based on IEEE 802.16 standard as a potential commercial off-the-shelf solution to support the communication requirements of the future war.
In the last few years, development in military and telecommunication industries have focused on an intensive use of broadband systems,...
Increased interest in the field of sensor technology stems from the availability of an inexpensive and robust sensor to detect and quantify the presence of a specific gas. Bulk p-CuO/n-ZnO heterocontact based gas sensors have been shown to exhibit the necessary sensitivity and selectivity characteristics, however, low interfacial CuO/ZnO contact...
Metal-insulator-metal (MIM) tunnel devices have been proposed for high speed applications such as hot electron transistors, IR detectors, optical rectennas for IR energy harvesting, and backplanes for LCDs. The majority of these applications require highly asymmetric and non-linear current versus voltage (I-V) behavior at low applied voltages and ultra-high frequencies....
Surface characterization of materials is widely utilized over a range of disciplines and essential to the development of new materials, technology, or processes. Metal oxide nanoclusters have shown promise as potential new generation photoresist materials for extreme ultraviolet (EUV) nanolithography. Organotin clusters have been proposed as potential candidates for resist...
Recent changes in legislation restricting lead content in waste streams produced during electronics manufacturing have inspired a strong push to develop alternative lead-free materials systems for piezoelectric applications. One lead-free piezoelectric material system, (100-X)Bi₀.₅Na₀.₅TiO₃-XBi₀.₅K₀.₅TiO₃ (BNKT), has shown promising properties in bulk research, however, difficulties have arisen in the development of...
In this dissertation, the spectroscopic properties and thermodynamic stability of a class of materials known as metal oxo and hydroxo clusters are studied. In aqueous solutions, many metals can aggregate into discrete clusters of metals bridged by oxo or hydroxo ligands. These clusters are of particular interest to us for...
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...
Amorphous metal thin films lack the grain boundaries and dislocations present in
crystalline metal films. As a result, amorphous metal films can be more mechanically robust, atomically smooth, and more resistant to chemical attack than crystalline metals. However, amorphous metals are meta-stable and subject to crystallization upon heating, thus limiting...
The common cherrylaurel (Prunus laurocerasus) and Portuguese cherrylaurel (P. lusitanica) are economically important landscape shrubs across the United States. To gain a better understanding of physiology and morphology in these higher level polyploids (P. lusitanica, 2n = 8x; P. laurocerasus, 2n =22x), a variety of breeding experiments were performed. The...
The subject of this PhD thesis is part of a research domain of great present interest in new semiconductor materials for photovoltaic and thermoelectric applications. This domain contains the elaboration and the study of both Cu-based chalcogenides bulk and thin-film samples, driven by materials design principles.
One of the most...
Amorphous metal thin films (AMTFs) are of potential use for metal-insulator-metal (MIM) tunnel diode applications due to their ultra-smooth surfaces, a consequence of their amorphous microstructure. The objective of this thesis is to design a thermally-stable AMTF capable of maintaining MIM tunnel diode performance after a post-deposition anneal in excess...
A transient code (TFETC) for calculating the temperature
distribution throughout the radial and axial positions of a
thermionic fuel element (TFE) has been successfully developed.
It accommodates the variations of temperatures, thermal power,
electrical power, voltage, and current density throughout the
TFE as a function of time as well as...
In this report, the optical characteristics of ZnS:Tb AC driven thin-film
electroluminescent devices are evaluated. Luminescence at low and room temperature
under a constant phosphor field is recorded in order to probe the hot electron energy
distribution. Samples fabricated by atomic layer epitaxy and by sputter deposition are
investigated and...
This work is concerned with the modeling and analysis of lossy planar dielectric
optical waveguides. Loss mechanisms which affect propagation characteristics are
reviewed, and various representations of the propagation constant in the lossy case
are defined. Waveguide structures which are susceptable to absorption and/or to
leakage loss, in particular silicon-based...
Quality Function Deployment (QFD) is a product development process that
assures the needs and desires of the customer are heard and heeded during the
design, development and production of a product. Though it has been used
successfully in other industries, only a few companies in the U. S. Engineering
and...
This thesis describes compensation techniques for cascaded delta-sigma A/D
converters (ADCs) and high-performance switched-capacitor (SC) circuits. Various
correlated-double-sampling (CDS) techniques are presented to reduce the effects of the
nonidealities, such as clock feedthrough, charge injection, opamp input-referred noise and
offset, and finite opamp gain, in SC circuits. A CDS technique...
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...
New transparent p- and n-type semiconductors and luminescent materials have been prepared and characterized. Synthesis, structures, optical and electrical properties of new chalcogenide fluoride p-type transparent semiconductors MCuQF (M=Ba, Sr; Q=S, Se, Te) are described. Band-gap tuning and improvement in conductivity through p-type doping are demonstrated in the family. The...
Nanostructured ZnO films were obtained via thermal oxidation of thin films formed with metallic Zn-nanoparticle dispersions. Commercial zinc nanoparticles used for this work were characterized by microscopic and thermal analysis methods to analyze the Zn-ZnO core shell structure, surface morphology and oxidation characteristics. These dispersions were spin-coated on SiO₂/Si substrates...
Thin-film transistors (TFTs) are primarily used as a switching element in liquid crystal
displays. Currently, amorphous silicon is the dominant TFT technology for displays, but
higher performance TFTs will become necessary to enable ultra-definition resolution
high-frequency large-area displays. Amorphous zinc tin oxide (ZTO) TFTs were
fabricated by RF magnetron sputter...
The central focus of this thesis is the design, fabrication and characterization of amorphous oxide semiconductor (AOS) thin-film transistor (TFT) current mirrors. The thin-film deposition and circuit fabrication methods used to realize zinc tin oxide (ZTO) TFT
current mirrors are addressed in order to elucidate the processing challenges for this...
As electronics reach nanometer size scales, new avenues of integrating biology and electronics become available. For example, nanoscale field-effect transistors have been integrated with single neurons to detect neural activity. Researchers have also used nanoscale materials to build electronic ears and noses. Another exciting development is the use of nanoscale...
Trends in wireless networks are increasingly pointing towards a future with multi-hop
networks deployed in multi-channel environments. In this thesis, we present the design
for iMAC—a protocol targeted at medium access control in such environments. iMAC
uses control packets on a common control channel to faciliate a three-way handshake
between...
Amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) constitute the central theme of this thesis. Within this theme, three primary areas of focus are pursued.
The first focus is the realization of a transparent three-stage ring oscillator with buffered output and an output frequency in the megahertz range. This leads to...
As a preliminary step toward the establishment of a
70 mm. aerial photo timber inventory system capable of
generating accurate stand tables, stock tables, and gross
volume estimates, this project focuses on the development
of a system which (1) eliminates the need to measure tree
height on the photos through...
The objective of this thesis is to introduce and demonstrate a novel magnetic bead detector based on inductive detection at the ferromagnetic resonance (FMR) frequency for use in bio-sensing applications. Detection ability is demonstrated through theoretical arguments, numerical computer simulations, and experimental characterization of micro-fabricated detectors.
The detector is composed...
This thesis describes a Systemic Vulnerability Identification and Remediation (SVIR) methodology that identifies human fallibilities and errors in complex technical processes, and recommends remediations for the errors, based on human factors principles and guidelines. The objectives of the research described in the thesis are the development of the methodology and...
The Philippines relies heavily on timber product exports for its foreign exchange requirements. In recent years, however, it adopted log export restrictions as a hedge against the rapid depletion of its timber resources. Although conducted independently, its ASEAN partners (Malaysia and Indonesia), have likewise instituted similar restrictions on their own...
The primary objective of this thesis is to develop a process for fabricating integrated circuits based on thin-film transistors (TFTs) using zinc tin oxide (ZTO) as the channel layer. ZTO, in contrast to indium- or gallium-based amorphous oxide semiconductors (AOS), is perceived to be a more commercially viable AOS choice...
Amorphous oxide semiconductors (AOSs) are of great current interest for thin-film transistor (TFT) channel layer applications. In particular, indium gallium zinc oxide (IGZO) is under intense development for commercial applications because of its demonstrated high performance at low processing temperatures. The objective of the research presented in this thesis is...
The focus of this thesis is the investigation of thin-film transistors (TFTs) based on amorphous oxide semiconductors (AOSs) in two circuit applications. To date, circuits implemented with AOS-based TFTs have been primarily enhancement-enhancement inverters, ring oscillators based on these inverters operating at peak frequencies up to ~400 kHz, and two-transistor...
The general emphasis of this work has been synthesis, characterization, and applications of n- and p-type inorganic oxide thin films that are deposited from solutions. In particular, a study of n-type transparent semiconductor films of tin (IV) oxide and zinc-doped tin (IV) oxide has been performed by spin coating. Solution...
Streptococcus gordonii is a bacterial species that naturally colonizes the oral cavity of most healthy humans. It resides in the mouth as an adherent to dental surfaces and, with few exceptions, does not cause disease in individuals it inhabits. It possesses qualities that encourage its use as a vector to...
This thesis focuses on two aspects of transparent electronics, SnO₂ transparent thin-film transistors (TTFTs) and transparent circuits. Both depletion- and enhancement-mode SnO₂ TTFTs are realized. The maximum effective mobility for the depletion- and enhancement-mode devices are 2 cm²V⁻¹s⁻¹ and 0.8 cm²V⁻¹s⁻¹, respectively. A variety of techniques to decrease the carrier...
The distribution of adult Pacific herring (Clupea harengue
pallasi) near Auke Bay, Lynn Canal, southeastern Alaska, varied by
depth and geographic area over 24 successive months during 1973-75.
From June through September, schools concentrated at 5- to 37-m
depths where zooplankton was abundant, and moderate currents were
present in a...
It has been well established that ferroelectric to relaxor crossover in piezoelectric ceramics exhibit promising electromechanical and dielectric properties over a wide temperature range, applying sensors and actuators transducers and such. A plethora of research has reported giant strain in various lead-free piezoelectric ceramics and attributed the reasoning to the...
With the rapid growth of worldwide internet traffic in data centers and clouds, silicon photonics has been utilized to provide enormous data bandwidth and outstanding energy efficiency over electronics. Computing servers and storage servers that are connected by communication links are relying more on optical rather than electrical means mainly...
Oxo-hydroxo Group 5 metal clusters are an untapped resource to study and advance aqueous solution processing of metal oxide thin films. The tetramethylammonium (TMA) hexatantalate salt (TMA6[H2Ta6O19]) yields dense Ta2O5 films (~95% of the bulk ß-Ta2O5 density) with atomically smooth surfaces (<4 Å root mean square surface roughness). This same...
Due to a lack of grain boundaries, an amorphous metal thin film (AMTF) possesses advantageous mechanical properties and enhanced chemical stability that is potentially useful for thermal inkjet (TIJ) printing applications. The use of an AMTF as a TIJ resistor or cavitation plate could lead to a thinner TIJ cavitation...
In this thesis an introduction to simulation and object oriented programming discusses the need for the creation of several classes which directly support object oriented simulation. The author places no restrictions on the type of simulations that can be conducted and simulation practitioners will find that the classes provided lay...
More than 30 members of the diverse amphidinolide family of biologically active macrolides have been isolated over last three decades. From this family, amphidinolides C and F stand among the most complex and densely functionalized affiliates. Recently, we have accomplished the first total synthesis of amphidinolide F. The all-carbon framework...
Indium-gallium-zinc oxide (IGZO) and zinc-tin oxide (ZTO) are investigated for thin-film transistor (TFT) applications. Negative bias illumination stress (NBIS) is employed for electrical stability assessment. Unpassivated IGZO and ZTO TFTs suffer from severe NBIS instabilities. Zinc-tin-silicon oxide is found to be an effective passivation layer for IGZO and ZTO TFTs,...