The Use of Thermoelectric Peltiers to Recapture Waste Heat

Peltier devices are a method of converting differences in temperature into electrical energy. Using data from a supplier of these devices, calculations were made to determine the efficiency of these devices in conjunction with a residential solar hybrid electric system. The initial calculations show efficiencies less than 2% with the temperature differences experienced during the springtime. While this efficiency doesn\u27t sound stellar, taking into account the current efficiency of residential solar cells, this would be an appreciable addition to the power output of a residential solar system

The Use of Thermoelectric Peltiers to Recapture Waste Heat

Peltier devices are a method of converting differences in temperature into electrical energy. Using data from a supplier of these devices, calculations were made to determine the efficiency of these devices in conjunction with a residential solar hybrid electric system. The initial calculations show efficiencies less than 2% with the temperature differences experienced during the springtime. While this efficiency doesn\u27t sound stellar, taking into account the current efficiency of residential solar cells, this would be an appreciable addition to the power output of a residential solar system

Temporal demography of lesser scaup: a species in decline

2020 Summer.Includes bibliographical references.A central goal of wildlife management and conservation is to determine which demographic parameters have the greatest influence on population growth rate to focus management actions for species of concern. Understanding how environmental conditions influence intra- and interannual variation in demographic parameters, and in turn population growth rates, requires long-term studies. This allows researchers to account for temporal covariation in demographic parameters that may have a greater influence on population dynamics than direct variation in the demographic parameter. One such species that could benefit from a better understanding of temporal variation and covariation in demographic parameters is lesser scaup (Aythya affinis, hereafter scaup), which has declined continentally since the early 1980's. I contributed to and utilized a long-term study of scaup demography at Red Rock Lakes National Wildlife Refuge in southwestern Montana, USA to 1) explore how environmental conditions influenced intra- and inter- annual variation in clutch size and nest survival, and 2) incorporate temporal (co)variation in demographic parameters into population models to decouple the influence of parameter variation, versus covariation, on population growth rate. To address my first objective, I considered an array of environmental covariates that were hypothesized to influence inter-annual variation in clutch size and nest survival such as water levels, water level phenology, and water temperature. In addition, I considered intra-annual covariates that could influence these vital rates, such as nest initiation date and day of the breeding season, which could serve as proxies for seasonal changes in resources, predators, or both. Clutch size varied much more within years across nest initiation dates (3.18-10.05), than it did across years (7.51 – 8.38). Given the constrained range of clutch sizes across years, none of the environmental covariates exhibited significant relationships with clutch size. In contrast, nest survival varied little intra-annually (e.g. 2018 nest survival 0.38 ± 0.03), but greatly interannually (0.27 – 0.58). Water level phenology did influence nest survival, such that years when maximum lake levels were reached late in the breeding season relative to mean nest initiation date, had the highest nest survival rates. To address my second objective, I incorporated results from my first chapter along with annual estimates of female breeding propensity, duckling survival, first-winter survival of females, adult female seasonal survival, process variance of each vital rate, and correlation between each pair of vital rates into a time-variant population model and conducted a prospective and retrospective perturbation analysis of population growth rates. The population model revealed that the study population is declining by approximately 6% each year. Results from the prospective perturbation analysis indicated that breeding season and non-breeding season adult survival had the highest stochastic elasticities (0.84 and 0.82 respectively), and thus had the greatest potential to influence the stochastic population growth rate. Whereas, retrospective analyses indicated that fluctuations in duckling survival made the largest contribution to realized population growth rates in the past (64%). Additionally, covariation in demographic rates explained 37% of variation in realized growth rates compared to 63% being attributable to direct temporal variation in the vital rates. These findings collectively suggest efforts to manage water phenology at Red Rock Lakes National Wildlife Refuge could positively influence nest survival and efforts should focus on finding ways to increase duckling survival to have the greatest impact on population growth rate. More broadly, covariation in demographic rates can explain a large proportion of variation in population growth rate and should be incorporated into population models of declining species to more accurately determine points in the life cycle that truly drive population dynamics, and therefore provide sound information to managers aiming to conserve the species

Extensible Interface for a Compact Spectrophotometer for Teaching Molecular Absorption in the Undergraduate Laboratory

A simple computer interface for controlling a compact spectrograph for use as a spectrophotometer in an undergraduate teaching laboratory was developed. The project was implemented on a Raspberry Pi computer which permits the integration of a light source into the software. The interface was written in Python to facilitate modification by the user and because of its compatibility with several computing platforms. An implementation of the project in Linux on a Raspberry Pi computer is described

Determination of predominant species of oil-degrading bacteria in the oiled sediment in Barataria Bay, Louisiana

The effects of the Deepwater Horizon (DWH) oil spill on the bacterial communities in coastal sediments are relatively known but few studies have been published evaluating the impacts of the spill on oil-degrading bacterial populations in the salt marsh sediments of Barataria Bay, Louisiana. The aims of this study were to determine the effects of the oil spill on the microbial community in Barataria Bay, Louisiana through the determination of predominate species of oil-degrading bacteria in marsh sediments, and to determine how well certain bacterial isolates can degrade crude oil in the region by taking samples from three areas of different oiling categories in April 2012, October 2012 and April 2013, approximately 24, 30, and 36 months after the initial oiling event. Hydrocarbon-degrading bacteria were isolated from the sediment samples using Bushnell Haas (BH) agar enriched with 1% Light Louisiana Sweet (LLS) crude oil. The isolates were subsequently purified on LB agar plates, their genomic DNAs extracted, and 16S rRNA genes amplified by polymerase chain reaction (PCR). The PCR products of 16S rRNA were then sequenced and taxonomically classified based on similarity to known sequences in BLAST database. A total of 460 isolates were obtained, representing 84 species from 45 genera in 6 phyla. Oil degradability of 10 bacterial isolates, designated to Staphylococcus xylosus, Acinetobacter calcoaetious, Pseudomonas stutzeri, Bacillus pumilus, Micrococcus luteus, Rhodococcus equi, Microbacterium esteratomaticum, Vibrio sp., Pseudomonas mendocina, and Agromyces aurantiacus, respectively, was tested in LB broth with 1% LLS crude oil. Their growth and metabolic properties in terms of optical density at 600 nm and pH in culture medium were monitored for 6 days. Among these isolates, Micrococcus luteus, Vibrio sp., Bacillus pumilus, Rhodococcus equi and Microbacterium esteratomaticum appeared to have the greatest ability to degrade LLS crude oil; their growth rates were estimated to be 0.038, 0.037, 0.031, 0.029 and 0.037 per hour, respectively. All isolates showed a decrease in pH in their culture medium during their growth, with M. esteratomaticum having the lowest pH of 5.29 and R. equi having the highest pH of 6.50 at 96 hours of incubation. A decrease in pH in the cultured media is indicative of an accumulation of acid from oxidation reactions carried out by oil-degrading bacteria. The present study provided a comprehensive list of indigenous oil-degrading bacteria in Louisiana marsh sediment, which is critical in developing bioremediation strategies

Commercial Helicopter Services: Toward Quantitative Solutions for Understanding Industry Phenomena and Achieving Stakeholder Optimization

An understanding of industry phenomena and optimization techniques within the upstream energy industry’s transportation sector is markedly absent in the extant literature and suitable for rigorous investigation. This manuscript presents analyses related to the optimization of offshore worker transportation and econometric analyses of factors influencing commercial helicopter operators’ stock returns, which are represented throughout the manuscript as Part I and Part II, respectively. The global energy industry transports supplies and personnel via helicopter to offshore locations and has been increasingly focusing on optimizing upstream logistics. Using a unique sample of deepwater and ultra-deepwater permanent offshore locations in the Gulf of Mexico, transportation networks consisting of 58 locations operated by 19 firms are optimized via a randomized greedy algorithm. The model developed in Part I has been found to effectively solve the complex transportation problem and simulation results show the potential advantages of alternative clustered and integrated network structures, as compared to an independent firm-level structure. The evaluation of clustered and integrated network structures, which allow ride sharing via energy firm cooperation, provides evidence that such network structures may yield cost reductions for participating firms. The extent to which commercial helicopter operators’ stock returns are related to commodity prices and other relevant industry variables is absent in the extant literature. Often, firms attribute favorable results to internal factors whereas unfavorable results are attributed to external factors. Using a unique data set from 2013-2018, the current research identifies structural relationships between crude oil prices, natural gas prices, the rotary rig count, a subset of the overall market, firms’ degree of diversification and stock returns of commercial helicopter operators. Empirical analyses developed in Part II show that the prevalent price of crude oil and the overall market environment possess explanatory power of commercial helicopter firms’ stock returns, ceteris paribus. Specifically, 10% increases in the crude oil price and the S&P 500 index yield a 2.7% and 8.0% increase in stock returns, respectively. Collectively, the abovementioned parts of this manuscript provide rigorous, quantitative analyses of topics unrepresented within the extant literature, which are foundational for future practice and research. Specifically, new knowledge regarding a practical approach to model development and solution deliverance for the transportation of offshore workers to their respective locations and factors influencing commercial helicopter operators’ stock returns has been appropriately designed and empirically evaluated