Studies of the nature of interfacial barriers in high efficiency crystalline silicon solar cells

The effects of interfacial barriers in crystalline silicon solar cells were studied. The effort was directed toward the investigation and use of such techniques as Angular Resolved Parameter Spectroscopy (ARAPS) and Impedance Spectroscopy in initially characterizing n-type Si doped to levels commonly used for n+p solar cells, and eventually Si solar cells. The objectives of the research are given. Those accomplished are detailed, as are recommendations for future work

Examining perceived subordinate support

Support relationships within organizations have been the subject of numerous empirical studies. Much of this research has focused on the influence of perceived organizational support and perceived supervisor support and their effects on subordinates. To date, however, no research has focused on how supervisors are influenced by their beliefs about support from their subordinates. I define perceived subordinate support (PSubS) as the extent to which a supervisor feels subordinates are concerned with the supervisor\u27s well-being and value the supervisor as a leader. Previous research suggests that subordinates’ opinions and behaviors do influence supervisor behavior. In the present study, a measure of PSubS and a measure of supervisor self-efficacy (SSE) were created and administered along with Eisenberger et al.’s (1986) measure of perceived organizational support (POS) to two samples of supervisors. The two new measures were validated using principle components factor analysis. The results indicated that PSubS is a unique construct distinct from POS and SSE. Implications and recommendations for future research are discussed

Evaluation of event data recorders in real world crashes and full-scale crash tests

With the advent of advanced safety systems in U.S. passenger vehicles, there has been increased interest shown by automakers in recording crash related parameters that ultimately lead to the deployment of these safety systems in what are known as Event Data Recorders (EDRs). Since the only other record of these parameters, specifically crash pulse, comes from staged crash tests in a controlled environment, the advent of the EDR has become increasingly important to crash researchers. The purpose of this study is to quantify the performance of EDRs in full-scale crash tests and real world crashes. Comparison of EDRs with staged crash tests included 6 General Motors vehicles. The EDRs performed well in staged crash tests reporting delta-V accurately in five of six tests. They were able to report other crash related parameters such as driver seat belt and airbag deployment status accurately in five of six tests as well. Comparison of EDRs with real world accident reconstructions was performed for 315 General Motors cases and 10 Ford cases from the National Automotive Sampling System Crashworthiness Data System (NASS / CDS) database. Computer generated (WinSmash) values for delta-V showed the tendency to underestimate delta-V for high-speed deployment events and overestimate delta-V for low-speed nondeployment events when compared to the GM EDR. The Ford EDR showed a lack of sufficient recording duration to draw any concrete conclusions on the accuracy of its delta-V value

The significance of marine-derived biogenic nitrogen in anadromous Pacific salmon freshwater food webs

Thesis (Ph.D.) University of Alaska Fairbanks, 1991The natural abundance of the stable isotope ratios \sp{15}N/\sp{14}N and \sp{13}C/\sp{12}C expressed as \delta\sp{15}N and \delta\sp{13}C was used to trace biogenic nutrients delivered by returning adult anadromous Pacific salmon into freshwater systems. These systems were Sashin Creek, a rapidly flushing stream located on Baranof Island, southeastern Alaska and Iliamna Lake, the major sockeye salmon, Oncorhynchus nerka, nursery lake in the Kvichak River watershed, Bristol Bay, southwestern Alaska. Marine-derived nitrogen (MDN) was quantifiable by use of an isotope mixing model based on comparison of biota \delta\sp{15}N in areas used for spawning by anadromous salmon with salmon-free controls within the same watershed. Control periphyton (benthic primary producers) \delta\sp{15}N values $\sim$0 suggested that the control N pool was derived from N\sb2 fixation without significant recycling. In contrast, periphyton abundant in areas of intense spawning activity or carcass aggregation had \delta\sp{15}N $\sim$ +7. These two values were the basis for comparison of \delta\sp{15}N values of higher trophic level biota. A mixing model relating \delta\sp{15}N to MDN with trophic level was used to estimate consumer MDN through incorporation of a priori isotopic trophic enrichment factors established in the literature. Distinctive \delta\sp{13}C signatures along the Sashin Creek stream gradient and between Iliamna Lake littoral and limnetic production were used in concert with \delta\sp{15}N. Sashin Creek fishes reflected isotopic signatures of periphyton and thus production within the same stream section. Isotopic data suggested an overall importance of limnetic production in Iliamna Lake resident fish and juvenile sockeye salmon diets. Salmon eggs and emergent fry retaining the parental marine isotopic signature were distinguishable from autochthonous production derived from marine N, and appear to be a minor dietary component in both Sashin Creek or Iliamna Lake fishes. The proportion of MDN in resident fish N, including juvenile salmon after turnover of the natal N pool, was proportional to the escapement of spawners. Thus there is now direct evidence for a significant natural fertilization process: the flow of remineralized marine-derived biogenic nutrients from returning anadromous Pacific salmon into freshwater food webs