As modern systems continue to increase in size and complexity, they pose significant safety and risk management challenges. System engineers and much of the government research efforts are focused on understanding the attributes and characteristics that emerge from the interactions of components and subsystems. As a result, the objective of...
A series of new ternary graphite intercalation compounds (GICs) containing alkaline earth metal cations (M = Mg, Ca, Sr, Ba) and ethylenediamine (en) are reported. These GICs are deep blue to green in color and can be prepared as phase-pure compounds by the direct reaction of graphite powder with the...
Interest in nanomaterials is motivated partly by their potential for sensor arrays to detect
different gases. Nanowires in particular are of interest because their high surface-to-volume
ratio promises the possibility of high sensitivity. However, because of their discrete
quasi-one-dimensional geometry, electrical integration of nanowires into photolithographically
defined devices and circuits...
In this work, stainless steel wire cloth (SSWC) for metallic support was thermally treated to increase the adhesive strength of Al₂O₃ by improving superficial roughness. After coating Al₂O₃ on SSWC, Pt particles as a catalytic component were deposited on the Al₂O₃/SSWC. These supports and catalysts were characterized by N₂ gas...
This dissertation presents a phase domain in-loop-bandwidth spread-spectrum clock generation technique. In this proposed technique, a charge-based discrete-time loop filter is proposed to enable the phase domain in-loop-bandwidth spread-spectrum modulation without a delta-sigma modulator or time-to-digital converter. The in-loop-bandwidth modulation technique maximizes the loop bandwidth to improve phase noise suppression...
The ubiquity of high quality video and proliferation of mobile devices has contributed to an unprecedented rise in video consumption. HTTP, in conjunction with adaptive streaming, has become the de facto mechanism for delivering the vast majority of video as it readily caters to heterogeneous networks and devices. This dissertation...
The aim of the research undertaken for this thesis was to develop a new high-performance amorphous oxide semiconductor (AOS) for use as a channel layer in a thin-film transistor (TFT). AOS TFTs offer higher electron mobility than the established amorphous silicon based technology. A new channel material comprised of aluminum...
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...
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...
Rhizopus microsporus is a globally ubiquitous opportunistic human and plant pathogen that is known to harbor endosymbiotic bacteria. Differences between populations of clinical and environmental R. microsporus isolates have yet to be assessed on a global scale. Whole-genome sequence data were used to explore fungal biology and to assess potential...
The demand from consumers for more sustainable products, and the need to comply with government regulations motivates manufacturers to evaluate their operations for opportunities to reduce environmental impact and improve economic competitiveness. Manufacturers have actively improved the sustainability performance of their products through the use of sustainability assessment methods and...
We demonstrate that unidirectionally aligned, free-standing multi-walled carbon nanotubes (CNTs) exhibit highly anisotropic linear and nonlinear terahertz (THz) responses. For the polarization parallel to the CNT axis, strong THz pulses induce nonlinear absorption in the quasi-one-dimensional conducting media, while no nonlinear effect is observed in the perpendicular polarization configuration. Time-resolved...
Ample research has demonstrated the largely untapped potential of bioactive peptides (BAPs) for treating systematic chronic inflammation (SCI). Protein hydrolysates are the mixture of peptides resulting from the hydrolytic breakdown of a protein. Numerous hydrolysates contain BAPs and exert beneficial effects in both in vitro and in vivo models. In...
Task persistence has been associated with task mastery in many different realms of learning, and is thought to be evoked particularly through the observation of positive models; however, the capability of such exposures to transfer across domains is not currently well-understood. The present study sought to examine the effect of...
Investigations on the application of self-assembled monolayers (SAM) to indium gallium zinc oxide (IGZO) thin film transistors (TFT) for fabrication and channel modification are presented. The back channel of IGZO thin film transistors can be modified by the absorption of self-assembled monolayers. The electrical properties of the IGZO exposed back...
The development of technologies such as Building Information Modeling (BIM), light detection and ranging (lidar), and sensor-based systems poses new opportunities for researchers to rethink how construction safety and health can be approached during the design, planning, and construction phases of a project. Nevertheless, the majority of the technology applications...
The variegated aqueous chemistries of metal cations are applied to the design and synthesis of non-toxic solution precursors suitable for additive printing of large-area oxide electronics. Polycondensation behaviors of aqueous Al+3 and PO4 +3 are manipulated in the deposition of atomically smooth amorphous aluminum oxide phosphate (AlPO) dielectric films. AlPO...
Phosphate and peroxide stabilize new oxo-hydroxo niobium clusters in water at low pH. The clusters open a new chapter in aqueous niobium chemistry under acidic conditions. The clusters also produce atomically smooth, amorphous niobium oxide phosphate (NbPOx) thin films. Reaction pathways from cluster solutions to amorphous niobium oxide phosphate solids...
Aromatic hydrocarbons represent a large class of environmental contaminants that have a broad range of structures, physicochemical properties, and toxicities. Arising from the burning of organic matter, particularly fossil fuels, they are both widespread and abundant in all environmental compartments. Both monoaromatic hydrocarbons (BTEX) and polycyclic aromatic hydrocarbons (PAHs) are...
In this study the enzymatic activity of adsorbed Thermomonospora fusca E₅ and Trichoderma reesei CBHI cellulases were investigated using fluorescence techniques. In particular, cellulases were allowed to contact hydrophobic polystyrene surfaces under conditions of different solution concentrations, and adsorption times. Each of these variables is known to have a potential...
Emerging data showing the presence of atmospheric microplastics (MPs) has recently raised awareness surrounding the potential of human nanoplastics (NPs) exposure. Due to factors such as weathering, UV exposure, and other biodegradation processes, plastic pollution in the environment breaks down over time into micro (<5 micrometers) and nanoscale (<1000nm) particles....
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...
Many studies have shown that ground beetles feed on different agricultural pests, but little is known about their species communities from US cropping systems. We assessed the biological control potential of the most common carabid beetle species in Oregon annual ryegrass grown for seed by investigating spatial and temporal overlap...
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...
Atomic layer deposition (ALD) is an enabling technique for many new micro- and nanoscale technologies. The self-limiting surface chemical reactions by which ALD fundamentally operates give rise to uniquely high precision (atomic) control over deposited film thickness, uniformity over large areas, and conformality over complex and extreme topographies. One such...
The continuous improvement of construction operations requires a systematic approach of monitoring and making appropriate control actions. However, the lack of real-time information hinders this workflow and eventually compromises timely and effective decision-making. Project managers spend a great deal of time and effort to solve problems emerging from lack of...
Commercial whaling during the 20th century drastically reduced many populations of great whales in the Southern Hemisphere. The Antarctic blue whale, for example, is estimated to have been reduced to less than 0.1% of its original abundance based on catch records and population dynamic models. Despite this population bottleneck, several...
A method for large quantity dsRNA production was developed since a small amount of dsRNA synthesized in vitro with commercial kits are used for small scale bioassay evaluations. Developing a large-scale production system for dsRNA is critical for practical RNAi application, especially for non-transgenic RNAi-based control. However, large-scale analysis or...
Peroxiredoxins (Prxs) are dominant peroxide-reducing enzymes with two important roles: they protect all organisms from oxidative damage induced by peroxides, and in eukaryotes, they participate in hydrogen peroxide signaling pathways. This dissertation presents studies aimed at the biophysical characterization of select Prxs and a Prx reductase to elucidate their structure-function...
The reaction conditions for the synthesis of Cu-BTC (BTC = benzene-1,3,5-tricarboxylic acid) were elucidated using a continuous-flow microreactor-assisted solvothermal system to achieve crystal size and phase control. A high-rate synthesis of Cu-BTC metal-organic frameworks with BET surface area of more than 1600 m²/g (Langmuir surface area of more than 2000...
Full Text:
., Chang, C. H., Wannenmacher, N., Thallapally,
P. K., & Ahn, H. G. (2013). High-rate synthesis of Cu-BTC
Vibrio cholerae, a Gram-negative bacterium, is the etiological agent of cholera. V.
cholerae shuttles between the human host and the aquatic reservoir, where it associates
with marine organisms such as copepods and vertebrate fish. The bacteria use the Type II
Secretion System (T2SS) to release proteins that facilitate V. cholerae...
High-pressure torsion (HPT) is an effective severe plastic deformation (SPD)
technique to produce bulk nanostructured materials (BNMs). These BNMs often show a combination of exceptional mechanical and physical properties. Processing of single metals and alloys by HPT has been understood that the homogenous microstructures can be achieved throughout the disk...
We report the use of MIL-120 as a water-stable and cost-effective metal-organic framework (MOF) for selectively capturing CO₂ from wet flue gas. Synthesized using inexpensive and environmentally benign reagents in water, MIL-120 possesses one-dimensional pores decorated with hydroxyl-bridged Al(III) ions and benzene rings with an interstitial spacing of 4.78 Å....
Vibrio bacteria are commonly found in freshwater, marine, and estuarine environments. Members of this genus can exist in commensal relationships with marine animals or as planktonic bacteria, however, they are well known for their roles as pathogens towards humans and animals. In this dissertation, I investigated aspects of host-bacteria relationships...
The primary focus of this thesis is modifying the comprehensive depletion-mode model and extending its applicability to p-channel thin-film transistor (TFT) behavior and subthreshold (subpinchoff) operation. The comprehensive depletion-mode model accurately describes depletion-mode TFT behavior and establishes a set of equations, different from those obtained from square-law theory, which can...
The advent of high-throughput sequencing (HTS) methods has enabled direct approaches to quantitatively profile small RNA
populations. However, these methods have been limited by several factors, including representational artifacts and lack of
established statistical methods of analysis. Furthermore, massive HTS data sets present new problems related to data processing
and...
Automation of computational chemistry, while only an engineering feat, has the potential to accelerating computational research be removing all by the science. The work in this thesis mainly discusses fundamental understanding of complex chemical systems. What is not obvious are the numerous tasks necessary for this fundamental understanding. Under the...
The development of nanomaterials and the potential enhancement of their chemical, mechanical, electrical, and optical properties have led to the investigation of methods for their synthesis at lower cost with enhanced performance for next generation devices. Along with the pursuit of new materials that exhibit properties of interest, industry requires...
Aerobic organisms have evolved many sensory mechanisms that allow
response to oxidants in the environment. One area of interest is the relationship
between the activity of the tumor suppressor protein p53 and the redox state of
thioredoxin. Human p53 activity is severely compromised in budding yeast lacking
thioredoxin reductase. Evidence...
In this work, colloidal PbSe quantum dots (QDs) are shown to be synthesized in a controlled manner by changing the growth time and reaction temperature in a microwave synthesis method. It is explained why quantum dots make such a unique material to create electronic devices and the specific benefits that...
NAND flash based solid state drives (SSDs) require out-of-place updating due to the characteristics of flash memories. In addition, due to the mismatched granularity between read/write and erase operations, a cleaning policy involving garbage collection and wear leveling has to perform data migration incurring high overhead. Another challenge is that...
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...
Ever increasing global internet data traffic has driven up the demand for cutting-edge high-speed wireline communication systems including SerDes PHY for various interfaces, interconnects, data centers servers and switches in optical systems. Operating wireline communications at higher data rates leads to signals suffering from greater channel loss and exponential increase...
Scaling of CMOS technology has progressed relentlessly for the past several
decades. In order for this unprecedented scaling to benefit the performance of
large digital systems, the communication bandwidth between integrated circuits
(ICs) must scale accordingly. However, interconnect technology does not scale as
aggressively, making communication between chips the major...
Phase-Locked Loops (PLLs) are essential building blocks in many communication systems. Designing high performance analog PLLs in the presence of technology imposed constraints such as leakage, poor analog transistor behavior, process variability, and low supply voltage is a challenging task. To overcome these drawbacks, digital PLLs (DPLLs) have recently emerged...
The continued scaling of deep-submicron CMOS technology enables low-voltage high-frequency phase-locked loops (PLLs) to be fully integrated in complex mixed-signal systems. However, fluctuations due to the manufacturing process and variations in
environmental conditions, such as supply voltage and temperature, are also significantly increased. As a result, the performance of PLLs...
Faithful modeling of the expected gamma signals inside an electrochemical facility at various key measurement points is important for understanding what detection limits are available for the next generation of safeguards technologies. Gamma Detector Response and Analysis Software (GADRAS) and the Separation Safeguards Performance Model (SSPM) were used to build...
Boiling dynamics and related heat transfer mechanisms have been widely studied for several decades. During that time, incredible progress has been made on quantifying bubble departure phenomena including growth rate, departure frequency, associated natural and forced convection, and radiation additions to the overall heat transfer rate. With this, the thermal...
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...