Quantum transport and spin-orbit coupling in semiconductor nanostructures

Semiconductor nanostructures present a promising path to enhance current computing technology and develop quantum information technologies. The electronic structure of these nanostructures has direct implications on the transport of electrons through them and their potential device applications. This thesis explores the electronic structures of various semiconducting nanostructures and their dependence on electromagnetic fields, dopant atoms, spin-orbit coupling and atomistic features through experiment and modelling. A form of quantum transport, known as single electron charging, is demonstrated through the electron-bound states of dopant atoms in a silicon nanostructure. A portion of a recently published work is presented which models the response of valley states in a gate-defined quantum dot within a silicon quantum well to an interface step and applied electric fields. The main work of this thesis employs an atomistic tight-binding model to determine the effective g-factor anisotropy of InAs nanowires under various atomistic and electromagnetic conditions. The spin-orbit interactions present in the nanowires are extracted from the effective g-factor anisotropy with an effective model. The modelling results provide insights for InAs nanowire applications in fields such as Majorana zero mode research, spintronic devices and quantum information technology.Thesis (MPhil) -- University of Adelaide, School of Physics, Chemistry and Earth Sciences, 202

Trace Elements in Oklahoma Soils: Content, Availability, and the Effect of Phosphorus Fertilizer and Organic Amendment Application

Trace elements in soil are important both for the necessity of some for life and for their potential toxicity when present in elevated levels. Micronutrient availability is important to crop production and can be affected by long-term application of phosphorus (P) fertilizer and other amendments. This study was conducted to determine the effects of the long term application of inorganic and variably sourced organic amendments on micronutrient availability. Extractable (DTPA-sorbitol) and total micronutrients were determined from sites that had long-term application of beef manure, swine effluent, biosolids, or commercial fertilizer across Oklahoma. Three continuous inorganic P experiments that have been conducted for 36 to 39 years and two organic amendment experiments that have been conducted for 11-12 years were evaluated. Soil properties including organic matter, pH, and total soil P were also determined. In the case of micronutrient toxicity, baseline levels need to be established in order to determine the extent of anthropogenic influences to a site. Total trace element levels were determined for 28 benchmark soils of Oklahoma and path analysis was used to determine relationships between these trace element levels and the soil properties pH, OC, clay content, CEC, Alox and Feox. Different relationships were observed between DTPA-extractable micronutrients and total P for different P sources. Significant relationships (p < 0.01) were found between DTPA-extractable Cu, Zn, Fe, and Mo and total P applied in the biosolids amended plots. For the beef manure plots, significant relationships existed between DTPA-extractable B, Fe, Zn, Cu, and Mn and total P applied. Significant relationships were also found between extractable B, Zn, and Cu and total P applied for the swine effluent plots. However, significant relationships were not found between the vast majority of inorganic commercial P fertilizer treatments and DTPA-extractable micronutrients. Long-term application of organic amendments increased micronutrient availability, but long-term application of inorganic P had no effect on micronutrient availability. Trace element concentrations varied in Oklahoma soils. The trace elements Cd, Cr, Cu, Ni, Pb, and Zn were significantly correlated with clay content while Mn was correlated with Alox.Department of Plant and Soil Science

Sero-prevalence and risk factors for Severe Acute Respiratory Syndrome Coronavirus 2 infection in women and children in a rural district of Bangladesh: A cohort study.

BACKGROUND: Bangladesh reported its first COVID-19 case on March 8, 2020. Despite lockdowns and promoting behavioural interventions, as of December 31, 2021, Bangladesh reported 1.5 million confirmed cases and 27 904 COVID-19-related deaths. To understand the course of the pandemic and identify risk factors for SARs-Cov-2 infection, we conducted a cohort study from November 2020 to December 2021 in rural Bangladesh. METHODS: After obtaining informed consent and collecting baseline data on COVID-19 knowledge, comorbidities, socioeconomic status, and lifestyle, we collected data on COVID-like illness and care-seeking weekly for 54 weeks for women (n = 2683) and their children (n = 2433). Between March and July 2021, we tested all participants for SARS-CoV-2 antibodies using ROCHE's Elecsys® test kit. We calculated seropositivity rates and 95% confidence intervals (95% CI) separately for women and children. In addition, we calculated unadjusted and adjusted relative risk (RR) and 95% CI of seropositivity for different age and risk groups using log-binomial regression models. RESULTS: Overall, about one-third of women (35.8%, 95% CI = 33.7-37.9) and one-fifth of children (21.3%, 95% CI = 19.2-23.6) were seropositive for SARS-CoV-2 antibodies. The seroprevalence rate doubled for women and tripled for children between March 2021 and July 2021. Compared to women and children with the highest household wealth (HHW) tertile, both women and children from poorer households had a lower risk of infection (RR, 95% CI for lowest HHW tertile women (0.83 (0.71-0.97)) and children (0.75 (0.57-0.98)). Most infections were asymptomatic or mild. In addition, the risk of infection among women was higher if she reported chewing tobacco (RR = 1.19,95% CI = 1.03-1.38) and if her husband had an occupation requiring him to work indoors (RR = 1.16,  95% CI = 1.02-1.32). The risk of infection was higher among children if paternal education was >5 years (RR = 1.37, 95% CI = 1.10-1.71) than in children with a paternal education of ≤5 years. CONCLUSIONS: We provided prospectively collected population-based data, which could contribute to designing feasible strategies against COVID-19 tailored to high-risk groups. The most feasible strategy may be promoting preventive care practices; however, collecting data on reported practices is inadequate. More in-depth understanding of the factors related to adoption and adherence to the practices is essential

Comparative Advertising Wars: An Historical Analysis of Their Causes and Consequences

This historical study contributes to the extensive literature on comparative advertising by examining the causes and consequences of comparative advertising wars; that is, when one advertiser responds to a direct or implied attack by another advertiser. Primary and secondary sources consist of articles published in historic and contemporary marketing and advertising trade journals, such as Printers’ Ink, Advertising & Selling, and Advertising Age. The findings reveal that well-publicized advertising wars occurred frequently between major U.S. advertisers throughout the twentieth century and into the twenty-first, and that they most often occurred in product and service markets characterized by intense competition. Many, if not most, advertisers’ principal motive for responding to a comparative advertising attack has been emotional rather than rational. The findings also reveal that advertising wars often became increasingly hostile, leading to negative consequences for all combatants, as well as a broad and negative social consequence in the form of potentially misleading advertising.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Competition and Combative Advertising: An Historical Analysis

Fred K. Beard (PhD, University of Oklahoma) is a professor of advertising in the Gaylord College of Journalism and Mass Communication, University of Oklahoma. His research interests include comparative advertising, advertising humor, and advertising history. His work has appeared in the Journal of Advertising, the Journal of Advertising Research, the Journal of Business Ethics, the Journal of Business Research, Journalism History, the Journal of Historical Research in Marketing, the Journal of Macromarketing, and the Journal of Marketing Communications, among others.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Occurrence, Fate, and Transport of Pesticides and Their Degradation Products in Urban Environments

In highly urbanized areas, intensive use of pyrethroids has led to offsite transport to surface waters at concentrations known to cause toxicity to aquatic organisms. However, there is limited knowledge on the occurrence and distribution of pyrethroids in urban settings, or the role dust particles play in offsite transport of pyrethroids. Additionally, when pyrethroids enter the environment, they undergo transformation to form a common degradation product 3-phenoxybenzoic acid (3-PBA), which has been shown to cause endocrine disruption. However, little research has been conducted on the formation of 3-PBA in urban environments, its occurrence in urban streams, or its stability in different environmental matrices. Here we first evaluated the occurrence of particle-borne insecticides including pyrethroids in outdoor urban dust and studied their spatial and temporal distribution patterns and correlation with particle sizes. Temporally, particle-bound insecticides increased over the dry season and then significantly decreased after winter rains. Spatially, levels of pyrethroids in dust did not differ with distance from point of application, suggesting redistribution. Pyrethroids were found to associate predominantly with the smallest particle size fraction in dust. These findings suggest that loose particles are likely a significant source for offsite contamination of insecticides. In a subsequent study, we investigated pyrethroid transformation processes on concrete and 3-PBA formation. Pyrethroid degradation was rapid with hydrolysis being the most significant pathway, leading to rapid formation of 3-PBA. Low levels of 3-PBA were constantly detected in urban surface water, suggesting the need to understand chronic exposure and risk to aquatic species. In order to aid risk assessment of 3-PBA, in the last study we examined its stability in different environmental matrices. The half-life of 3-PBA in surface water and aerobic sediments was relatively short, while it was prolonged in soil and anaerobic sediments. These results further suggested that urban soil may be a source of 3-PBA to surface water or underlying groundwater, and due to the continuous input, additional research is needed to evaluate adverse effects on non-target organisms

Is it too easy to be green? :a comparative analysis and critical assessment of green building rating systems

With a continued emphasis on designing for sustainability in architecture, it is important to see what role green rating systems are playing and what differences they are making. There are many options when it comes to choosing a green rating system for a particular project, and their metrics can vary greatly. Names such as LEED and BREEAM have a large global presence and a long standing relationship with green design. Others, like the Living Building Challenge, are pushing criteria to higher standards. By examining popular green rating systems, one can get a better idea of their fundamentals -what concepts each system evaluates and emphasizes. Comparatively analyzing specific projects certified under these various rating systems then reveals how such systems manifest themselves in the built environment. Finally, crossreferencing this data with practicing academic and professional subjects' views helps to formulate a clearer image of what implications green rating systems are having today and what their continued role may be in the future of architectural design.Honors CollegeThesis (B.?

Enhancing Antibacterial Properties Using Herbal Extracts

Intramammary infections caused by some stands of Escherichia coli have been known to acquire antibiotic resistance. Therefore, other methods should be sought out to find an effective therapy that does not include antibiotics. Information on how anti-inflammatories coupled with homeopathic practices affect Escherichia coli is insufficient. The objective of this experiment is to discover whether anti-inflammatories and organic compounds combined would have a detrimental effect on Escherichia coli. The Escherichia coli inhibiting power was evaluated both individually and combination of banamine, dexamethasone with either cinnamomum cassia oil or aromatic turmeric (curcuma aromatica) extract. Paper disks (8mm) was saturated in the different solutions and placed directly onto a lawn of Escherichia coli housed in a petri dish for each trial. Antibacterial activity results are presented here

Is it too easy to be green? :a comparative analysis and critical assessment of green building rating systems

With a continued emphasis on designing for sustainability in architecture, it is important to see what role green rating systems are playing and what differences they are making. There are many options when it comes to choosing a green rating system for a particular project, and their metrics can vary greatly. Names such as LEED and BREEAM have a large global presence and a long standing relationship with green design. Others, like the Living Building Challenge, are pushing criteria to higher standards. By examining popular green rating systems, one can get a better idea of their fundamentals -what concepts each system evaluates and emphasizes. Comparatively analyzing specific projects certified under these various rating systems then reveals how such systems manifest themselves in the built environment. Finally, crossreferencing this data with practicing academic and professional subjects' views helps to formulate a clearer image of what implications green rating systems are having today and what their continued role may be in the future of architectural design.Thesis (B.?)Honors Colleg