Submitted by Daniele Santos (danielesantos.htl@gmail.com) on 2017-02-21T20:29:41Z No. of bitstreams: 1 Gus Davidson.pdf: 970488 bytes, checksum: 476e7012037f6f72d871810a4fdaf8f5 (MD5) / Approved for entry into archive by Janete de Oliveira Feitosa (janete.feitosa@fgv.br) on 2017-02-23T16:38:01Z (GMT) No. of bitstreams: 1 Gus Davidson.pdf: 970488 bytes, checksum: 476e7012037f6f72d871810a4fdaf8f5 (MD5) / Made available in DSpace on 2017-02-24T12:39:36Z (GMT). No. of bitstreams: 1 Gus Davidson.pdf: 970488 bytes, checksum: 476e7012037f6f72d871810a4fdaf8f5 (MD5) Previous issue date: 2016-11-10 / Health care is a rapidly evolving industry with new technologies constantly entering the marketplace. Supply for quality care has to continuously catch up to demand. The United States’ primary care system is at a crossroads, as patients rightly demand the best in health care costs, access, and quality. How will the industry continue to deliver high quality of care with our nation’s increasing demands? What technologies can be best utilized when caring for our aging population? This thesis is built around key sections that address our country’s impending physician shortage and how our health care system can combat growing demand with better processes and technologies. First, this thesis will examine physician shortages in America and what opportunities are available to address the problem. Existing health care research has found that advanced practice providers improve the costs, access, and quality of care as a solution to the impending shortage. This review will also assess the effectiveness of advanced care providers and health systems using telehealth, and how technology can alleviate the primary care physician shortage. An analysis was also conducted to document the United States’ current ratio of physician to patients in each state, which shows that adding advanced primary care providers and telehealth services can narrow the gap between supply and demand in most states. Second, this thesis will analyze the impact of telehealth in the U.S. health care system. A literature review of telehealth’s definition and history will give a foundation of how the technology has already changed how Americans access care, especially in rural areas. This thesis is proposing that advance practice providers can deliver primary care services using telehealth. Through the review of studies and literature, in addition to interviews with industry experts, it is suggested that there is a lack of concrete evidence with which to fully assess the economic impact of telehealth. Two of the most common economic evaluation methods are cost-utility analysis (CUA) and cost-effectiveness analysis (CEA). The main x objective of CUA, which is used especially in health technology assessment, is to estimate the ratio between the cost of a health-related intervention and the benefit it produces in terms of the number of years lived in full health by the users. In health technology assessments, the benefits are usually expressed in quality adjusted life years.1

The aim of this thesis is to develop a deeper understanding and the technology in the nascent field of solid-state organic-inorganic perovskite solar cells. In recent years, perovskite materials have emerged as a low-cost, thin-film technology with efficiencies exceeding 16% challenging the quasi-paradigm that high efficiency photovoltaics must come at high costs. This thesis investigates perovskite solar cells in more detail with a focus on incorporating plasmonic nanostructures and perovskite film formation. Chapter 1 motivates the present work further followed by Chapter 2 which offers a brief background for solar cell fabrication and characterisation, perovskites in general, perovskite solar cells in specific, and plasmonics. Chapter 3 presents the field of plasmonics including simulation methods for various core-shell nanostructures such as gold-silica and silver-titania nanoparticles. The following Chapters 4 and 5 analyze plasmonic core-shell metal-dielectric nanoparticles embedded in perovskite solar cells. It is shown that using gold@silica or silver@titania NPs results in enhanced photocurrent and thus increased efficiency. After photoluminescence studies, this effect was attributed to an unexpected phenomenon in solar cells in which a lowered exciton binding energy generates a higher fraction of free charge. Embedding thermally unstable silver NPs required a low-temperature fabrication method which would not melt the Ag NPs. This work offers a new general direction for temperature sensitive elements. In Chapters 6 and 7, perovskite film formation is studied. Chapter 6 shows the existence of a previously unknown crystalline precursor state and an improved surface coverage by introducing a ramped annealing procedure. Based on this, Chapter 7 investigates different perovskite annealing protocols. The main finding was that an additional 130°C flash annealing step changed the film crystallinity dramatically and yielded a higher orientation of the perovskite crystals. The according solar cells showed an increased photocurrent attributed to a decrease in charge carrier recombination at the grain boundaries. Chapter 8 presents on-going work showing noteworthy first results for silica scaffolds, and layered, 2D perovskite structures for application in solar cells.

Quantitative analysis of trends in vegetation cover, especially in Kogi state, Nigeria, where agriculture plays a major role in the region’s economy, is very important for detecting long-term changes in the phenological behavior of vegetation over time. This study employs the use of normalized difference vegetation index (NDVI) [global inventory modeling and mapping studies 3g (GIMMS)] data from 1983 to 2011 with detailed methodological and statistical approach for analyzing trends within the NDVI time series for four selected locations in Kogi state. Based on the results of a comprehensive study of seasonalities in the time series, the original signals are decomposed. Different linear regression models are applied and compared. In order to detect structural changes over time a detailed breakpoint analysis is performed. The quality of linear modeling is evaluated by means of statistical analyses of the residuals. Standard deviations of the regressions are between 0.015 and 0.021 with R2 of 0.22–0.64. Segmented linear regression modeling is performed for improvement and a decreasing standard deviation of 33%–40% (0.01–0.013) and R2 up to 0.82 are obtained. The approach used in this study demonstrates the added value of long-term time series analyses of vegetation cover for the assessment of agricultural and rural development in the Guinea savannah region of Kogi state, Nigeria.