Master of Science

thesisChapter 1 examines the stratigraphic architecture of the lower straight cliffs formation across the southwestern portion of the Kaiparowits Plateau in southern Utah. To determine the controls affecting deposition of marginal marine deposits, seven stratigraphic sections (each ~90-100m) and 729 paleocurrents were measured along a 20 km transect (A-A'). This study divides the lower Straight Cliffs Formation into four depositional units (DU), representing distinct and genetically-related depositional environments: prograding shoreface parasequences (DU-1), tidally influenced fluvial channels and estuaries (DU-2), a transitional sequence of shoreface deposits through fluvial deposits (DU-3), and downstream accreting fluvial deposits (DU-4). This interpretation represents both minor and more significant revisions to previous interpretations of this succession, and highlights the need for high-resolution stratigraphic studies to fully understand depositional compexity in this and similar settings. Earth scientists often use images to communicate scientific concepts, and they commonly provide cues establishing the scale of features shown ('hammer for scale,' etc). How effective are these kinds of scaling cues? Chapter 2 examines the effect of scaling cures and interactivity on the ability of earth scientists to extract information from 2 2D image. To evaluate both scaling cues and interactivity, a visualization test was created in which participants were asked to estimate the size of several boxes shown in outcrop photos. All test subjects first viewed a static image, followed by an interactive (gigapan) image of the same outcrop; two different outcrops of different sizes were used. Participants (test group =63, further testing in progress) represent a range of experience and education levels. Results show that scaling estimates are more difficult for larger/more distant outcrops. Scaling cues can also become a distractor for viewers of any experience level or background. It is important to realize that viewers internalize scaling cues differently, so different types of cues may help some viewers more than others. Also it appears that incorporating interactivity can increase accuracy, due to the ability to customize views that best fits an individual's learning style and internal sense of problem solving, The results of this study contain numerous educational implications for the application of scale and interactivity

A ‘Good Employer’ Perceptions and Practice in Small Enterprises

The research explored the concept of a ‘good employer’ pertaining to employment relations and occupational health and safety (OHS) in small enterprises (SE’s). How perceptions, attitudes and beliefs of a ‘good employer’ were implemented in practice, were surveyed in a sample of SE’s using a framework developed from the International Labour Organisation (ILO) socially Decent Work Index (DWI). The study retained the DWI’s key dimensions: employment security, voice security, income security, skill reproduction security, and work security. However, measures of the key dimensions were broadened to capture the predominantly individualistic nature of employment relations in SE’s. The employers’ perceptions generally corresponded with the two dimensions of the ‘good employer’ prioritized by the ILO: employee voice and income security. In practice, there were instances of employees having input beyond operational matters. Nevertheless employers unilaterally determined pay and other terms and conditions of work. As for work security, the level of formal and informal policies and practices varied but employers who operated in higher OHS risk trade industries generally implemented comprehensive formal OHS management systems. It is argued that all it takes to be a ‘good employer’ is compliance with statutory employment minima. The employers in this study generally fulfilled this basic standard with some employers demonstrating higher levels of the characteristics that fitted with the dimensions associated with some large enterprises and the concept of a ‘good employer’ developed in the public sector. To accommodate space limitations, only brief summaries of the employer’ perceptions, attitudes and beliefs of a ‘good employer’ and Work Security are provided. This paper focuses on the results concerning voice and income security

Wide-Bandgap Device Enabled Multilevel Converters With Simplified Structures and Capacitor Voltage Balancing Capability

This paper aims to point out and demonstrate the opportunities enabled by wide-bandgap (WBG) devices for multilevel converters, contributing to the international technology roadmap for WBG power semiconductors (ITRW). The emergence of silicon carbide (SiC) and gallium nitride (GaN) devices offers new opportunities to push the boundaries of power converter performances. Featuring high single-device blocking voltage and ultra-low switching loss, WBG devices can enable a group of multilevel converters with simplified structures and a higher number of levels to be practically implemented in applications with various power levels. This paper highlights how the use of WBG devices can reduce the number of required devices in the simplified multilevel topologies, how the capacitor voltage balance can be achieved with the newly proposed redundant level modulation (RLM) enabled by the ultra-low switching loss of WBG devices and how the switching frequency and efficiency can be improved with WBG multilevel converters. A 1.2 kV/100 kW, three-phase demonstrator implemented with a simplified four-level active neutral point clamped (ANPC) structure and commercial SiC power modules is studied to show the opportunities brought by WBG devices for multilevel converters. A voltage balancing scheme based on the RLM and a power loss analysis are presented for this configuration

Reducing Tobacco Use and Access Through Strengthened Minimum Price Laws

Higher prices reduce consumption and initiation of tobacco products. A minimum price law that establishes a high statutory minimum price and prohibits the industry’s discounting tactics for tobacco products is a promising pricing strategy as an alternative to excise tax increases. Although some states have adopted minimum price laws on the basis of statutorily defined price “markups” over the invoice price, existing state laws have been largely ineffective at increasing the retail price. We analyzed 3 new variations of minimum price laws that hold great potential for raising tobacco prices and reducing consumption: (1) a flat rate minimum price law similar to a recent enactment in New York City, (2) an enhanced markup law, and (3) a law that incorporates both elements