Thesis (M.S.)--University of California, Santa Cruz, 1992. / Typescript. Includes bibliographical references (leaves 75-76).

Thesis (M.S.)--University of California, Santa Cruz, 1990. / Typescript. Includes bibliographical references.

Universiẗat, Diss., 2003--München.

Thesis (M.S.)--Brigham Young University. Dept. of Geology, 2005. / Includes bibliographical references (p. 15-19).

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on November 20, 2009). Thesis advisor: Dr. Mitchell Schulte. Includes bibliographical references.

Made available in DSpace on 2014-06-11T19:28:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2003Bitstream added on 2014-06-13T20:58:42Z : No. of bitstreams: 1 costa_agf_me_botfca.pdf: 338484 bytes, checksum: 9314cb65a12c9d3e9a4fd12627bae433 (MD5) / O presente trabalho teve como objetivo desenvolver e comparar métodos para estimar perdas em aplicações de herbicidas em pré-emergência, utilizando como traçadores o herbicida tebuthiuron e o corante Azul Brilhante, e diferentes alvos artificiais para coleta de deriva e deposição. Para tanto, foram realizadas duas aplicações em pré-emergência, simultâneas, com pulverizadores de barra equipados com pontas de pulverização modelo SF 11002 espaçadas a 0,5 m e a 0,5 m de altura em relação ao solo. Uma aplicação foi realizada com o traçador herbicida tebuthiuron na formulação suspensão concentrada (Combine 500 SC) e a outra com o traçador Azul Brilhante (FD&C-1), nas concentrações de 0,73 e 0,60% (p.v-1) e com volumes de calda de 167,75 e 163,75 L.ha-1, respectivamente. Para estimar as perdas utilizaram-se bandejas de isopor contendo 100 g de solo espalhados em sua superfície (coletores de deposição com área útil de 0,044288 m2), em 100 repetições, distribuídas dentro da área de aplicação e; fios de náilon de 2 mm de diâmetro (coletores de deriva), fixados na posição vertical de 0 a 5 m de altura em hastes de ferro de 1,59 cm de diâmetro e 6 m de comprimento que foram colocados fora da área de aplicação, nos 4 lados adjacentes (nas posições NO, SO, SE e NE), enfileirados e fixados à distâncias de 1, 2, 4, 8 e 16 m da área aplicada. As alturas dos coletores de deriva foram de 0 a 1, 1 a 2, 2 a 3, 3 a 4 e 4 a 5 m, totalizando 4 repetições para cada distância, em cada área adjacente. Após a aplicação e secagem da calda aplicada, o solo e os fios de náilon retirados dos coletores foram guardados em sacos de polietileno. Para a extração dos traçadores contido no solo oriundo dos coletores de deposição, foram utilizadas 2 porções de 10 g de cada repetição, sendo uma lavada com 50 mL de água destilada, para extrair o Azul Brilhante... . / The aim of this research was to develop and compare methods to estimate herbicide spraying losses in pre emergence application. Two compounds were used as tracer (brilliant blue FD&C-1 and the tebuthiuron herbicide), and two different artificial targets to collect the drift and deposition. Two pre emergence simultaneous sprays were released from two sprayer booms with nozzles model SF 11002 (Jacto S.A.) distant 0.5 m and 0.5 m height. One of the sprayer applied tebuthiuron herbicide and the other brilliant blue. The concentrations used were 0.73% and 0.60% (w/v) the volumes rates were 167.75 L.ha-1 for the tebuthiuron sprayer and 163.75 L.ha-1 for the brilliant blue. It was used to estimate the drift loss deposition colectors made of foam (trays with 100 g of soil spread on its superfice with 0.044288 m2). A hundred trays were distributed in the application area resulting in 100 repetitions. Drift collectors (nylon threads of 2 mm diameter vertically fixed between 0-5 m height on iron stens with 1.59 cm diameter and 6 m length) were placed around the application area. The drift collectors were placed in all directions (NW, SW, SE and NE) at 1, 2, 4, 8 and 16 m distant and 0-1, 1-2, 2-3, 3-4 and 4-5 m height com 4 repetitions for each distance. After the sprays the soil and the nylon threads were put in a plastic bag. The analysis of the tracers in the soil samples were realized with 50 mL of destilated water to extract the brilliant blue and 50 mL of methyl alcohol to extract the tebuthiuron. The nylon threads were washed with 40 mL destilated water for extract both tracers. The wash solutions were analysed with spectrophotometer to quantify the brilliant blue and high-performance liquid chromatography (HPLC) to quantify the herbicide tebuthiuron. The drift detected values were analyzed in fatorial design 4x5x5. Gompertz model provided the highest determinations coefficients...(Complete abstract, click electronic address below).

Essa tese de doutorado discute em ato o conceito de experiência através de um processo de trabalho inventivo denominado « Deriva Parada ». Com metodologia inspirada em elementos dos movimentos artísticos Surrealismo e o Situacionismo, buscou tensionar a palavra cidade, operando nela uma crise de sentido. A deriva e a deambulação foram dois procedimentos artísticos que agiram na suspensão dos usuais sentidos atribuídos ao termo e dotaram-lhe de potência criativa-criadora de novos sentidos, ou até mesmo, da possibilidade transmitir o vazio de sentido. Seguindo a leitura de autores como W. Benjamin, G. Agamben, G. Didi-Hubeman, G. Bataille em torno da questão da produção da experiência após a modernidade histórica, buscou-se um percurso em trabalhos de artistas, pensadores, além da experência-tema dessa tese: fagulhas da destruição da experiência e outras formas de existir, contar e produzir memória na cidade contemporânea. / This thesis discusses in act the concept of experience trough a process of inventive work denominated « Deriva Parada ». It sought for tensioning the word city, operating over it a crisis of meaning with a methodology inspired in elements of the artistic movements Surrealism and Situationism. The drift and the strolling were two artistic procedures that acted on the suspension of the usual meanings related to this concept and gave it a creativecreator power of new meanings, or even, possibilities of transmitting the absence of meaning. Following the readings of authors as W. Benjamin, G. Agamben, G. Didi-Hubeman, G. Bataille around the issue of the experience production after historic modernity, we sought a trajectory in works of artists, thinkers and the theme-experience of this thesis: destruction sparks of the experience and others forms of existing, telling and producing memory in the contemporary city.

This dissertation computationally and analytically investigates ways to model solar cells when the lateral motion of charge carriers and light are relevant. We focus on back-contact perovskite solar cells, and assessing the experimental technique of scanning photocurrent microscopy as a means to investigate them. Solar cells are three-dimensional objects frequently modelled as being one-dimensional. However, for more complex designs of solar cell or if the cell is only point-illuminated, one-dimensional modelling is insufficient. In the first study, some conditions for reducing the complexity of two-dimensional drift-diffusion simulations are investigated for a back-contact perovskite cell. Analytic expressions for the relationship in both the low extraction velocity and high extraction velocity regimes are demonstrated, and the conditions where these approximations break down are investigated. These findings are then applied a point-excited film with an extended electrode, a problem encountered during scanning photocurrent microscopy. We show the current recorded in this case should decay exponentially with the distance between excitation and electrode, with a decay constant that can be related to device parameters. The characteristic equilibration time for the system to reach this current is demonstrated to increase linearly with distance. Between this gradient and the exponent, information about the diffusion and recombination mechanics can be extracted from a variety of systems. Photon recycling is the process in whereby photogenerated carriers recombine to generate light that is absorbed again within the solar cell. In the second section, we apply the findings of the first section to show that experimental results published elsewhere are best explained by photon recycling in methylammonium lead iodide perovskite back-contact solar cells. However we do not have an established theoretical model for long-ranged lateral optical transport in these solar cells. Three models are developed: a bimolecular model for unscattered, coherent transport; a photon diffusion model for frequently scattered, noncoherent light; and a monomolecular, assisted-diffusion model. The modal nature of coherent optical transport is considered and modifications to previous one-dimensional theories are made. The nature of the photon diffusion model is discussed, as are theoretical shortcomings. All three models are then solved numerically and compared to experimental results. The low-scattering photon diffusion models correspond well to the experiment. The third investigation involves the performance of different architectures of back-contact perovskite cells. These cells potentially offer increased current due to less shadowing by front electrodes. We compare them to each other and to traditional vertical structures. It is found that, in terms of internal transport, the back-contact solar cells give less efficient performance than the vertical design. The best of the back-contact cells investigated is a flat interdigitated design. The increase in efficiency from optical factors would have to exceed 10% for the overall efficiency of back-contact cells to be higher than vertical devices. We also develop a model of photon recycling appropriate for short-ranged, bulk 2D transport and demonstrate that in perovskites, it produces little change in power conversion efficiency (and small changes in short-circuit voltage) when compared with the standard drift-diffusion equations with the second-order recombination constant is adjusted.

Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Florestal, 2008. / Submitted by Jaqueline Oliveira (jaqueoliveiram@gmail.com) on 2008-11-25T18:15:51Z No. of bitstreams: 1 TESE_2008_FernandoNunesGouveia.pdf: 1621334 bytes, checksum: 055e97d798bdc7c7d7142497acfefdd7 (MD5) / Approved for entry into archive by Georgia Fernandes(georgia@bce.unb.br) on 2009-02-09T14:59:06Z (GMT) No. of bitstreams: 1 TESE_2008_FernandoNunesGouveia.pdf: 1621334 bytes, checksum: 055e97d798bdc7c7d7142497acfefdd7 (MD5) / Made available in DSpace on 2009-02-09T14:59:06Z (GMT). No. of bitstreams: 1 TESE_2008_FernandoNunesGouveia.pdf: 1621334 bytes, checksum: 055e97d798bdc7c7d7142497acfefdd7 (MD5) / Neste trabalho, amostras de três espécies de madeiras tropicais, Simarouba amara, Sextonia rubra e Cariniana micrantha foram submetidas a quatro tratamentos térmicos com o objetivo de reduzir a variação da cor da superfície da madeira após um período de 84 horas de irradiação ultravioleta. Os tratamentos utilizados foram: I – temperatura de 150°C por uma hora; II – temperatura de 150°C por duas horas; III – temperatura de 200°C por uma hora; IV – temperatura de 200°C por duas horas. Para acompanhar a variação do teor dos compostos químicos na superfície das amostras foi utilizada uma técnica nãodestrutiva, conhecida como DRIFT – Espectroscopia de refletância difusa no infravermelho com transformada de Fourier. O teste foi conduzido em uma estufa de laboratório com ventilação forçada, à pressão atmosférica e sem controle de gases. Foram registrados os valores das variáveis colorimétricas L*, a*, b*, C e h*, de acordo com o Sistema CIELAB 1976, bem com a variação destes parâmetros, L, a, b e E. Ao final dos tratamentos térmicos as maiores variações de cor foram observadas nas amostras submetidas ao tratamento IV (200°C por duas horas). A análise dos interferogramas DRIFT mostrou que em todas as amostras houve perda de água e degradação das carbonilas. Também foi observado aumento no teor de compostos aromáticos, o que pode indicar uma possível migração de substâncias extrativas de camadas inferiores para a superfície da madeira. Após o período de exposição à radiação ultravioleta, as amostras de Simarouba amara submetidas ao Tratamento III e de Sextonia rubra, submetidas ao Tratamento II, apresentaram maior resistência à variação da cor do que amostras não tratadas destas espécies. As amostras de Cariniana micrantha, tratadas termicamente, não apresentaram melhorias quanto à fotodegradação. _________________________________________________________________ ABSTRACT / Three tropical wood species, Simarouba amara, Sextonia rubra and Cariniana micrantha, were submitted to four thermal treatments aiming to improve the resistance to photo degradation after 84 hours of ultraviolet irradiation. The treatments were: I - one hour at 150°C; II - two hours at 150°C; III - one hour at 200°C; IV - two hours at 200°C. The non-destructive technique known as DRIFT was used to compare the chemical changes of the wood components. The thermal modification was carried out in a common laboratory oven with air circulation at atmospheric pressure and without gas control. The colorimetric parameters of the CIELAB 1976 system: L*, a*, b*, C e h* were measured and the colorimetric variation calculated: L, a, b e E. After the application of the thermal treatments the greatest changes in color occurred with samples treated at two hours at 200°C (Treatment IV). The study of the DRIFT’s spectra showed that all wood specimens lost water and a migration of the extractives to the wood’s surface took place. After the ultraviolet irradiation period, Simarouba amara changed under treatment III and Sextonia rubra’ specimens were modified under treatment II, showing better performances as compared with the control samples. The thermal modification of Cariniana micrantha did not produced any improvement in the wood samples.

Essa tese de doutorado discute em ato o conceito de experiência através de um processo de trabalho inventivo denominado « Deriva Parada ». Com metodologia inspirada em elementos dos movimentos artísticos Surrealismo e o Situacionismo, buscou tensionar a palavra cidade, operando nela uma crise de sentido. A deriva e a deambulação foram dois procedimentos artísticos que agiram na suspensão dos usuais sentidos atribuídos ao termo e dotaram-lhe de potência criativa-criadora de novos sentidos, ou até mesmo, da possibilidade transmitir o vazio de sentido. Seguindo a leitura de autores como W. Benjamin, G. Agamben, G. Didi-Hubeman, G. Bataille em torno da questão da produção da experiência após a modernidade histórica, buscou-se um percurso em trabalhos de artistas, pensadores, além da experência-tema dessa tese: fagulhas da destruição da experiência e outras formas de existir, contar e produzir memória na cidade contemporânea. / This thesis discusses in act the concept of experience trough a process of inventive work denominated « Deriva Parada ». It sought for tensioning the word city, operating over it a crisis of meaning with a methodology inspired in elements of the artistic movements Surrealism and Situationism. The drift and the strolling were two artistic procedures that acted on the suspension of the usual meanings related to this concept and gave it a creativecreator power of new meanings, or even, possibilities of transmitting the absence of meaning. Following the readings of authors as W. Benjamin, G. Agamben, G. Didi-Hubeman, G. Bataille around the issue of the experience production after historic modernity, we sought a trajectory in works of artists, thinkers and the theme-experience of this thesis: destruction sparks of the experience and others forms of existing, telling and producing memory in the contemporary city.