published_or_final_version / Physiology / Master / Master of Philosophy

Notwithstanding several years of robust growth, solar energy still only accounts for<1% of total electrical generation in the US. Before solar energy can substantially replace fossil fuels subsidy-free at utility scale, further cost reductions and efficiency improvements are needed in complete generating systems. Flat panel silicon PV modules are by far the most dominant solar technology today, but have little room for improvement in efficiency and are limited by balance of system costs. Concentrated PV (CPV) is an alternate approach with long-term potential for much higher efficiency in sunny climates. In CPV modules, large area optics collect and concentrate direct sunlight onto small multi-junction cells with>40% conversion efficiency. Concentrated Solar Power (CSP) uses mirrors to concentrate sunlight onto thermally absorbing receivers, which generate electricity with convention thermal cycles. In this dissertation, four new optical approaches to CPV and CSP with potential for lower cost are analyzed. Common to each approach is the use of large square glass reflectors, which have very low areal cost (~$35/m^2) and field-proven reliability in the CSP industry. Chapter 2 describes a freeform toroidal lens array used to intercept the low concentration line focus of a parabolic trough to produce multiple high concentration foci (>800X) for multi-junction cells. In Chapter 3, three embodiments of dish mirrors and freeform lenslet arrays are explored, including an off-axis system. In each case, a dish mirror illuminates a freeform lenslet array, which divides sunlight equally to a sparse matrix of multi-junction cells. The off-axis optical system achieves +/-0.45° acceptance angle and averages 1215X geometric concentration over 400 multi-junction cells. Chapter 4 proposes a new architecture for CSP central receivers that achieves extremely high collection efficiency (>70%) with unconventional heliostat field tracking. In Chapter 5, the design and preliminary testing of a spectrum-splitting hybrid PV/thermal generator is discussed. This system has the advantage of 'drop-in' capability in existing CSP trough plants and allows for thermal storage, an important mitigation to the intermittency of the solar resource.

This dissertation describes the design, development, and field validation of a concentrator photovoltaic (CPV) solar energy system. The challenges of creating a highly efficient yet low-cost system architecture come from many sources. The solid-state physics of photovoltaic devices present fundamental limits to photoelectron conversion efficiency, while the electrical and thermal characteristics of widely available materials limit the design arena. Furthermore, the need for high solar spectral throughput, evenly concentrated sunlight, and tolerance to off-axis pointing places strict illumination requirements on the optical design. To be commercially viable, the cost associated with all components must be minimized so that when taken together, the absolute installed cost of the system in kWh is lower than any other solar energy method, and competitive with fossil fuel power generation. The work detailed herein focuses specifically on unique optical design and illumination concepts discovered when developing a viable commercial CPV system. By designing from the ground up with the fundamental physics of photovoltaic devices and the required system tolerances in mind, a select range of optical designs are determined and modeled. Component cost analysis, assembly effort, and development time frame further influence design choices to arrive at a final optical system design. When coupled with the collecting mirror, the final optical hardware unit placed at the focus generates more than 800W, yet is small and lightweight enough to hold in your hand. After fabrication and installation, the completed system's illumination, spectral, and thermal performance is validated with on-sun operational testing.

The basin factor is a hydrologic parameter that represents the overall impedance to flow of a watershed in the PC-Hydro peak discharge model for small ( < 10 mi2) semi-arid watersheds in Pima County, Arizona. To improve peak discharge estimates and provide validation of the basin factor as a physically-based parameter, basin factor values were "back-calculated" for return period and observed events on six undeveloped rangeland watersheds and correlated with Manning's n roughness coefficients, rainfall intensities, and hydraulic radii. Observed basin factor values displayed a positive trend with observed peak discharge. The results suggest that the correlated variables can predict the basin factor on small undeveloped sub-basins in Pima County and the basin factor is measurable as a physical parameter. Empirical models for basin factor prediction are proposed. The study may also be useful for estimating hydraulic roughness in hydrologic methods such as the kinematic wave time of concentration equation.

La seule mention d'un camp de concentration évoque instinctivement Auschwitz, Dachau, Bergen-Belsen, Büchenwald Ravensbrück... Ces noms restent gravés dans l'esprit contemporain. Par définition, toutefois, n'importe quel enclos qui emprisonne ou enferme des réfugiés, des prisonniers, ou même des étrangers hostiles, est un camp de concentration. Mais à cause des évènements historiques ce sont ces camps d'extermination qui nous reviennent à l'esprit. [...]

Introduction. There is ample evidence that using carbohydrates during physical exercise contributes to increasing the duration of the physical load being experIenced. Still research devoted to the study of using carbohydrate solutions of different concentrations and in different quantities is of great interest. No definite results as to the time of assimilation of carbohydrates in respect to the starting point of the physical load undertaken are available either. Carbohydrates are the main source of energy during intensive exercise. The body of the athlete requires a greater amount of carbohydrates since they present in themselves the most efficient source of energy that prolongs muscle function by providing possibilities for the energy to be generated both aerobically and anaerobically. The topicality of the present study lies in the fact that it is aimed at establishing the effect of different solutions on the working capacity of athletes. The hypotesis of the research is: the assimilation of extra glucose 20 min after the start of running helps to prolong the duration of running. The aim of the research done was to establish the effect of using glucose during running on the duration of running possible. Subjects and methods. The subjects were seven long – distance runners (age 23.0 ± 1.9 years, height 1.82 ± 2.7 m, weight 77.0 ± 7.85 kg and body mass index 23.79 ± 2.06 kg/m2). Information as to health condition of the subjects, their physical activity and nutrition was... [to full text]

Koncentracijų vertinimui ES, Lietuvoje ir JAV pasitelkiamos skirtingos koncentracijų vertinimo – „žymaus veiksmingos konkurencijos apribojimo“, „dominavimo“ ir „reikšmingo konkurencijos sumažinimo“ – taisyklės. Lietuvoje taikoma „dominavimo“ taisyklė neapima konkurencijos teisės draudimų taikymo oligopolinėse rinkose sukuriamam, vienašaliam neigiamam poveikiui rinkoje, kuris nelemia dominuojančios padėties sukūrimo ar sustiprinimo. Taip pat šios taisyklės pagrindu nepakankamas dėmesys skiriamas koncentracijų sukuriamo efektyvumo vertinimui. Nors ES ir JAV taikomų koncentracijų vertinimo taisyklių turinys yra tapatus – praktinis taisyklių taikymas nagrinėjamose jurisdikcijose yra skirtingas. Atliktas koncentracijų kontrolės tikslų, koncentracijos sąvokos, koncentracijos sudarymo būdų, ūkio subjekto sąvokos tyrimas, koncentracijų sukuriamų neigiamų bei teigiamų padarinių lyginamasis vertinimas parodė, kad pastarieji nagrinėjamos jurisdikcijose suprantami tapačiai. Buvo nustatyta, kad esminiai skirtumai pasireiškia koncentracijų kontrolės institucijoms nustatinėjant priežastinį ryšį tarp veikos (vykdomos koncentracijos) bei jos sukuriamų padarinių rinkoje. Vertinant horizontalias koncentracijas ir ES, ir JAV atsižvelgiama į tuos pačius, žymų, reikšmingą konkurencijos apribojimą lemiančius veiksnius, tačiau ES didesnis dėmesys skiriamas struktūrinių pasikeitimų rinkoje vertinimui, JAV – konkurencinių ryšių tarp koncentraciją vykdančių subjektų pasikeitimui. Nehorizontalių... [toliau žr. visą tekstą] / Concentrations in the EU, Lithuania and the US are assessed under different – “significant impediment of competition”, “dominance” and “substantial lessening of competition” – rules. Lithuanian “dominance” rule is not applicable to merger’s created unilateral effect in oligopolistic market if such merger doesn’t create or strengthen its dominant position. Furthermore, less attention is paid for efficiencies, created by mergers under this rule. While the content of the EU and the US concentrations assessment rules might seem alike – practical assessment of mergers proves the opposite. Moreover, comparative analysis of merger control goals, concepts of concentration and undertaking, ways of concentration and positive, negative effects of concentration showed that these are interpreted in the same way in all jurisdictions. It was also noticed that the main differences occur while identifying causality between concentration and its effects in the market. The same attention is paid to certain factors that might lessen competition substantialy during the horizontal mergers assessment process in the EU and the US. However, analysis applied in the EU are more of structural nature and the US concentration’s control institutions put focus on the assessment of competitive relationships between merged undertaking before and after the merger. The US is also more cautious about assessment of non-horizontal mergers. Competition authorities practically presume efficiencies created by the... [to full text]

The equipment for dosing out the solution has been created and the research of its technical characteristics has been done. It appeared that during a certain period of time, depending upon the quantity of solution, the concentration of the solution changes. Besides, with the help of the model, experiments concerning concentration of a solution were done, and the results about the changes of concentration are shown on a graphic.

Soybean [Glycine max (L.) Merr.] seed is a major source of edible oil in the world and the main renewable raw material for biodiesel production in North America. Oil, which on average accounts for 20% of the soybean seed weight, is a complex quantitative trait controlled by many genes with mostly minor effects and influenced by environmental conditions. Because of its quantitative nature, the seed oil concentration may have an indirect effect on other economically important and agronomic traits such as seed yield and protein concentration. Increasing the oil concentration in soybean has been given more attention in recent years due to increasing demand for both edible oil and feedstock. To achieve this objective, it is important to understand the genetic control of the oil accumulation and its relationship with other traits. The main objectives of this thesis were to identify quantitative trait loci (QTL) and genes involved in oil biosynthesis in soybean. Two recombinant inbred line (RIL) populations were developed from crosses between moderately high oil soybean cultivars with high seed yield and protein concentration. In a population of 203 F3:6 RILs from a cross of ‘OAC Wallace’ and ‘OAC Glencoe’, a total of 11 genomic regions located on nine different chromosomes were identified as associated with oil concentration using multiple QTL mapping (MQM) and single-factor ANOVA. Among the 11 oil-associated QTL, four QTL were also validated in a population of 211 F3:5 RILs from a cross of ‘RCAT Angora’ and ‘OAC Wallace’. There were six oil QTL identified in this study that were co-localized with seed protein QTL and four for seed yield QTL. The oil-beneficial allele of the QTL tagged by marker Sat_020, on Chromosome 9, was positively associated with seed protein concentration. The oil-enhancing alleles at markers Satt001 and GmDGAT2B were positively correlated with seed yield. In this study, three sequence mutations were also discovered in either the coding or non-coding regions of three DGAT soybean genes (GmDGAT2B, GmDGAT2C, and GmDGAT1B) between ‘OAC Wallace’ and ‘OAC Glencoe’ that showed significant effects on some of the traits evaluated. GmDGAT2B showed significant association with seed oil and yield across different environments. The oil-favorable allele of the gene GmDGAT2B from ‘OAC Glencoe’ was also positively correlated with seed yield. GmDGAT2C was associated with seed yield, whereas GmDGAT1B showed significant effects on seed yield and protein concentration. However, neither of these two genes showed any association with seed oil. The yield-enhancing allele of GmDGAT1B showed negative association with protein concentration. The identification of oil QTL that were either positively associated with seed yield and protein or neutral to both traits and the development of new gene-based markers will facilitate marker-assisted breeding to develop high oil soybean cultivars with high yield and minimal effect on protein concentration. / Generous funding to conduct this research was provided by the Alternative Renewable Fuels II Program of the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) and by the Grain Farmers of Ontario.

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