Measurements of Neutron Induced Surface and Bulk Defects in 4H Silicon Carbide

Epitaxial n-type 4H-silicon carbide (SiC) is irradiated with 2 MeV protons to evaluate the dislocation damage effects on the optical and electrical characteristics of the material. The optical properties of the material are investigated using temperature-dependant photoluminescence (PL) and the effects of proton irradiation on the electrical properties are evaluated using current-voltage measurements and constant-voltage deep level transient spectroscopy (CV-DLTS). Subsequent high-temperature thermal annealing and recovery of the irradiated material is investigated over the temperature range of 900-1500°C. Proton-induced irradiation damage is apparent in the 4H-SiC material, affecting both the optical and electrical characteristics of the devices. The radiative behavior of the nitrogen-related near band edge transitions is significantly reduced as a result of the irradiation with partial recovery observed after high-temperature thermal annealing at 1500 °C. A deeper trapping complex (EC-ET 380 meV) is detected as a result of irradiation and shows signs of activation due to thermal annealing. Initial indications taken from I-V measurements of the Schottky diodes reveal that proton irradiation followed by thermal annealing at 900°C may, in fact, enhance the rectifying device characteristics. Increasing the anneal temperature (TA = 1300°C) causes the device to fail entirely. Further annealing of the irradiated 4H-SiC at 1500°C demonstrates recovery in the rectifying behavior of the material. Significant levels of deep level donor traps are observed, induced by irradiation in n-type material. Three detectable defect pairs emerge with energy levels ranging from 570-730 meV below the conduction band. The trap parameters were determined using curve-fitting algorithms

An exploratory study of accommodations provided to welfare -to -work participants in housekeeping classifications

This study explored the workplace needs of welfare recipients in their transition from welfare to work, and the willingness of housekeeping managers and supervisors to provide workplace accommodations that could enhance the probability of a successful transition to self-sufficiency. Personal interviews and two separate survey questionnaires were used to survey employers and welfare recipients in an attempt to explore several research questions. Questions focused on the respective needs of employers and welfare recipients, and on each group\u27s perceptions of the other group. This exploratory study was supported by a literature review and survey techniques. Data was subjected to appropriate statistical analysis in order to generate conclusions and formulate hypotheses for future research

The Dilute Solution Chemistry of Antimony

Investigation of the chemistry of the elements by conventional methods is generally limited to concentrations on the order of 10-5 M or higher. The discovery of radio-activity opened new fields in chemistry among which is the obtaining of information concerning chemical behavior of elements at very low concentrations. For many years after the initial discovery of radioactivity in 1896 by Becquerel, the study of low-concentration chemistry was limited to about ten naturally occurring radioactive elements. A renewed interest in this field was generated after 1934 when it was discovered by Curie and Joliot that radioactive elements could be artificially produced

Map Use in Small-Town Planning Documents in Northeast Ohio

Author Institution: Department of Geography and Planning, University of AkronMaps are of fundamental importance to the planning profession. This paper examines the use of maps in planning documents from small towns in northeast Ohio. It considers the frequency of map use, the types of maps utilized, and their quality. Map quality is evaluated by determining the presence or absence of basic map elements and the utilization of a lettering hierarchy for the various map elements. Maps are found in all the plans (median =10) and these represent about one-quarter of non-textual materials. Maps of community facilities and land use are most common, accounting for over half of all maps. Key map elements are included on almost all maps, but few incorporate a lettering hierarchy to reflect the importance of the various elements. The increasing availability of computer mapping programs and the ease with which inadequate maps can be produced make it imperative that planners become more cognizant of the proper techniques for effective cartographic communication. More comprehensive studies are warranted examining the use of maps in planning documents from a wider range of types and sizes of administrative units—i.e., cities, metropolitan areas, and countie

Tuateawa

The Tuateawa project seeks to inform ecological understanding using analyses of soundscapes. Sound recordings are made in specific locations near Tuateawa in the Coromandel peninsula. This area is being monitored for the eradication of pests such as possums, stoats and rats. The research looks at how the soundscapes change over time, in particular: how is bird life affected by the presence of introduced noxious pests? And, how does human activity influence natural behaviours? The project is a form of documentary capturing detailed sound recordings every season for three or more years. The sound data is analysed for noticeable shifts in frequency and loudness, and output as various visual abstractions, the first of which is an audio visual work for LCD screens and speakers at Ramp Gallery 7-11 December 2020. The intended audience is intermediate age children to get them thinking about how these soundscapes might be understood and focused on through a less ‘scientific’ medium