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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Go tell it on the mountain a history of Narrow Ridge Earth Literacy Center, 1970-2004 /

Smith, Christopher T. January 2009 (has links) (PDF)
Honors project (B.A.) -- Carson-Newman College, 2009. / Project advisor: Dr. Beth Vanlandingham. Includes bibliographical references (p. 40-41).
62

Tl 9 BiTe 6 a new thermoelectric material with record efficiencies

Wölfing, Bernd. January 2001 (has links)
Konstanz, Univ., Diss., 2000.
63

Optimization of high efficiency thermoelectrics based on Tl5Te3

Teubner, Jens. January 2001 (has links)
Konstanz, Univ., Diplomarb., 2001.
64

Pesquisa de segunda neoplasia em boca e orofaringe em pacientes portadores de carcinoma espinocelular (CEC) de esôfago, boca e orofaringe através de "narrow band imaging (NBI)" /

Boldrini Junior, Domingos. January 2011 (has links)
Orientador: René Aloísio da Costa Vieira / Banca: Jair Cortez Montovani / Banca: José Magrin / Resumo: O câncer de boca e orofaringe apresentam incidência elevada em nosso meio, sendo o diagnóstico realizado em estádio avançado, onde a sobrevida é limitada. Neste sentido, faz-se importante avaliar e aprimorar métodos que visem ao diagnóstico precoce destas lesões. O uso do lugol ou do azul de toluidina tem limitações, e o exame clínico de rotina não é realizado rotineiramente na prática clínica, mesmo em populações de alto risco. A pesquisa neoplasia primária em pacientes de risco constitui um bom modelo na avaliação de novas metodologias de diagnóstico precoce do câncer de boca e orofaringe, sendo que a taxa de segunda neoplasia primária varia de 1 a 40%. Recentemente, o aparecimento de endoscópios com o recurso do Narrow-band imaging (NBI) tem demonstrado uma elevação na acurácia do diagnóstico de lesões neoplásicas, porém o número de trabalhos é limitado, havendo pouca experiência em nosso meio. Estudo prospectivo de pacientes portadores de carcinoma espinocelular de boca, orofaringe e esôfago, sem tratamento prévio, atendidos no Hospital de Câncer de Barretos no período de janeiro a agosto de 2010. Procurou-se avaliar a pesquisa de lesões préneoplásicas e segunda tumor primário (STP) na boca e orofaringe, utilizando-se o exame físico, associado a endoscopia com luz branca e a endoscopia com o recurso do NBI. As lesões visualizadas foram biopsiadas e as imagens digitalizadas. Utilizou-se a classificação patológica de WHO. Procurou-se avaliar a sensibilidade, especificidade, acurácia valores preditivos positivos e negativos e teste kappa da técnica do NBI em relação à técnica tradicional avaliando em as lesões pré-neoplásicas e neoplásicas. Foram avaliados 144 pacientes, sendo a maioria homens (86,8%), portadores de CEC de boca (44,4%), fumantes (80,6%) e etilistas (58,3%), com tumores em estádio STP em cabeça e pescoço... (resumo completo, clicar acesso eletrônico abaixo) / Abstract: Oral and oralpharyngeal cancer have high incidence in our country, being diagnosed at advanced stages, where survival is limited. In this sense is important to evaluate and improve methods aimed at early diagnosis, such as lugol's solution and toluidine, but both have limitations, and clinical evaluation, not always used in clinical practice, even in high risks population.The research of second primary tumor in high risks pacients is a good way to evaluate new methods of earlier diagnosis of oral and oralpharyngeal cancers. It's important to remember that the rate of second primary tumor varies between 1 to 40%. Recently, advent of endoscopes with the NBI feature (narrow band imaging) in endoscopy has demonstrated an increase in accuracy in cancer diagnosis, but the number of publications are still limited, with little experience in our midst. Cross-sectional, prospective, study of patients with oral carcinoma, pharynx and esophagus, untreated, in Cancer Hospital of Barretos, between january and august in 2010. Second primary tumor (SPT) in oral and oropharynx was searching using the association between clinical evaluation with white light endoscopy and NBI endoscopy. When lesions were presented it was biopsied and images digitalized. WHO pathologic classification was performed. The results of the both methods were compared regarding sensitivity, specificity, accuracy, positive predictive value and negative predictive value and kappa test. We evaluated 144 patients, being the majority men (86.8%) with OSCC (oral squamous cell carcinomas) (44.4%), smokers (80.6%) and alcoholics (58.3%), clinical stage neoplasia III and IV (77.0%). We identified nine neoplastic lesions and 16 dysplasia lesions. Head and neck SPT rate was 6,3%, but the rate of premalignant lesions and malignant in oral cavity and oropharynx was 17.4% and 30.0% when the primary site was oral cavity, 25.0% for esophagus... (Complete abstract click electronic access below) / Mestre
65

Search for narrow resonances in proton-proton collisions at sqrt{s} = 8 TeV decaying to z and higgs bosons in the two tau leptons and a merged jet pair final state

Bernardes, César Augusto January 2015 (has links)
Orientador: Prof. Dr Pedro Galli Mercadante / Tese (doutorado) - Universidade Federal do ABC, Programa de Pós-Graduação em Física, 2015. / We present a search in the CMS detector for a high-mass and narrow resonance decaying into a Higgs and a Z SM bosons in the final state with a pair of tau leptons and a pair of quarks. We analyze 19:7=fb of integrated luminosity of? s = 8 TeV proton-proton collisions from LHC. In the resonance mass range of interest (1:0 .. 2:5 TeV), the Z and Higgs bosons are produced with large momentum compared with their masses, which implies that the final products of the two quarks and the two taus must be detected within a small angular separation (boosted topology). Jet substructure techniques are used to identify the boosted Z boson decaying hadronically and a modified approach is considered to reconstruct very collimated pairs of tau leptons from boosted Higgs decay. From a combination of all possible decay modes of the tau lepton, heavy spin-1 resonances production cross sections are excluded at 95% C.L. in a range between 0:9 and 27:8 fb, depending on the resonance mass. We consider as benchmark model an effective description of a strongly coupled theory based on the Minimal Composite Higgs Model, which predicts heavy resonances with suppressed branching fractions into fermions. Comparing the experimental limits with analytical expressions of the parameters of a simplified model Lagrangian we obtain observed limits on these parameters, which are directly connected with the heavy resonance production and decay. / Apresentamos uma busca no detector CMS por ressonâncias massivas decaindo em um bóson de Higgs e um boson Z do Modelo Padrão no estado final com um par de leptons tau e um par de quarks. Analisamos 19; 7=fb de luminosidade integrada em colisões próton-próton com energia no centro de massa de 8 TeV no LHC. No intervalo de massa da ressonância entre 1; 0 .. 2; 5 TeV, os bósons Z e Higgs são produzidos com um momento grande comparado a suas massas, isso implica que os produtos finais provenientes de cada par de taus ou quarks devem ser detectados dentro de pequenas regiões espaciais. Técnicas de subestrutura de jatos são utilizadas para identificar o boson Z que decai em quarks. Para o Higgs decaindo em taus é definido um metodo modificado de reconstrução de pares de taus com alto momento e colimados. Combinando os resultados das análises de cada modo de decaimento do tau, são excluidas com 95% de confiança seções de choque de produção de ressonâncias com spin-1 no intervalo de 0; 9..27; 8 fb, dependendo da massa da ressonância. Consideramos como modelo de referência uma teoria efetiva de Higgs composto, que prediz ressonâncias massivas com pequena razão de ramificação em férmions. Comparando os limites experimentais com expressões analíticas dos parâmetros de uma Lagrangeana de um modelo simplificado, obtemos limites sobre esses parâmetros, os quais estão diretamente relacionados com a produção e decaimento das ressonâncias.
66

Pesquisa de segunda neoplasia em boca e orofaringe em pacientes portadores de carcinoma espinocelular (CEC) de esôfago, boca e orofaringe através de narrow band imaging (NBI)

Boldrini Junior, Domingos [UNESP] 16 March 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-16Bitstream added on 2014-06-13T18:50:21Z : No. of bitstreams: 1 boldrinijunior_d_me_botfm.pdf: 512291 bytes, checksum: 8823a68fb6704d2438a0ce58e025b019 (MD5) / Fundação Pio Xii - Barretos / O câncer de boca e orofaringe apresentam incidência elevada em nosso meio, sendo o diagnóstico realizado em estádio avançado, onde a sobrevida é limitada. Neste sentido, faz-se importante avaliar e aprimorar métodos que visem ao diagnóstico precoce destas lesões. O uso do lugol ou do azul de toluidina tem limitações, e o exame clínico de rotina não é realizado rotineiramente na prática clínica, mesmo em populações de alto risco. A pesquisa neoplasia primária em pacientes de risco constitui um bom modelo na avaliação de novas metodologias de diagnóstico precoce do câncer de boca e orofaringe, sendo que a taxa de segunda neoplasia primária varia de 1 a 40%. Recentemente, o aparecimento de endoscópios com o recurso do Narrow-band imaging (NBI) tem demonstrado uma elevação na acurácia do diagnóstico de lesões neoplásicas, porém o número de trabalhos é limitado, havendo pouca experiência em nosso meio. Estudo prospectivo de pacientes portadores de carcinoma espinocelular de boca, orofaringe e esôfago, sem tratamento prévio, atendidos no Hospital de Câncer de Barretos no período de janeiro a agosto de 2010. Procurou-se avaliar a pesquisa de lesões préneoplásicas e segunda tumor primário (STP) na boca e orofaringe, utilizando-se o exame físico, associado a endoscopia com luz branca e a endoscopia com o recurso do NBI. As lesões visualizadas foram biopsiadas e as imagens digitalizadas. Utilizou-se a classificação patológica de WHO. Procurou-se avaliar a sensibilidade, especificidade, acurácia valores preditivos positivos e negativos e teste kappa da técnica do NBI em relação à técnica tradicional avaliando em as lesões pré-neoplásicas e neoplásicas. Foram avaliados 144 pacientes, sendo a maioria homens (86,8%), portadores de CEC de boca (44,4%), fumantes (80,6%) e etilistas (58,3%), com tumores em estádio STP em cabeça e pescoço... / Oral and oralpharyngeal cancer have high incidence in our country, being diagnosed at advanced stages, where survival is limited. In this sense is important to evaluate and improve methods aimed at early diagnosis, such as lugol´s solution and toluidine, but both have limitations, and clinical evaluation, not always used in clinical practice, even in high risks population.The research of second primary tumor in high risks pacients is a good way to evaluate new methods of earlier diagnosis of oral and oralpharyngeal cancers. It’s important to remember that the rate of second primary tumor varies between 1 to 40%. Recently, advent of endoscopes with the NBI feature (narrow band imaging) in endoscopy has demonstrated an increase in accuracy in cancer diagnosis, but the number of publications are still limited, with little experience in our midst. Cross-sectional, prospective, study of patients with oral carcinoma, pharynx and esophagus, untreated, in Cancer Hospital of Barretos, between january and august in 2010. Second primary tumor (SPT) in oral and oropharynx was searching using the association between clinical evaluation with white light endoscopy and NBI endoscopy. When lesions were presented it was biopsied and images digitalized. WHO pathologic classification was performed. The results of the both methods were compared regarding sensitivity, specificity, accuracy, positive predictive value and negative predictive value and kappa test. We evaluated 144 patients, being the majority men (86.8%) with OSCC (oral squamous cell carcinomas) (44.4%), smokers (80.6%) and alcoholics (58.3%), clinical stage neoplasia III and IV (77.0%). We identified nine neoplastic lesions and 16 dysplasia lesions. Head and neck SPT rate was 6,3%, but the rate of premalignant lesions and malignant in oral cavity and oropharynx was 17.4% and 30.0% when the primary site was oral cavity, 25.0% for esophagus... (Complete abstract click electronic access below)
67

Phosphorescent Organic Light Emitting Diodes Implementing Platinum Complexes

January 2014 (has links)
abstract: Organic light emitting diodes (OLEDs) are a promising approach for display and solid state lighting applications. However, further work is needed in establishing the availability of efficient and stable materials for OLEDs with high external quantum efficiency's (EQE) and high operational lifetimes. Recently, significant improvements in the internal quantum efficiency or ratio of generated photons to injected electrons have been achieved with the advent of phosphorescent complexes with the ability to harvest both singlet and triplet excitons. Since then, a variety of phosphorescent complexes containing heavy metal centers including Os, Ni, Ir, Pd, and Pt have been developed. Thus far, the majority of the work in the field has focused on iridium based complexes. Platinum based complexes, however, have received considerably less attention despite demonstrating efficiency's equal to or better than their iridium analogs. In this study, a series of OLEDs implementing newly developed platinum based complexes were demonstrated with efficiency's or operational lifetimes equal to or better than their iridium analogs for select cases. In addition to demonstrating excellent device performance in OLEDs, platinum based complexes exhibit unique photophysical properties including the ability to form excimer emission capable of generating broad white light emission from a single emitter and the ability to form narrow band emission from a rigid, tetradentate molecular structure for select cases. These unique photophysical properties were exploited and their optical and electrical properties in a device setting were elucidated. Utilizing the unique properties of a tridentate Pt complex, Pt-16, a highly efficient white device employing a single emissive layer exhibited a peak EQE of over 20% and high color quality with a CRI of 80 and color coordinates CIE(x=0.33, y=0.33). Furthermore, by employing a rigid, tetradentate platinum complex, PtN1N, with a narrow band emission into a microcavity organic light emitting diode (MOLED), significant enhancement in the external quantum efficiency was achieved. The optimized MOLED structure achieved a light out-coupling enhancement of 1.35 compared to the non-cavity structure with a peak EQE of 34.2%. In addition to demonstrating a high light out-coupling enhancement, the microcavity effect of a narrow band emitter in a MOLED was elucidated. / Dissertation/Thesis / Doctoral Dissertation Materials Science and Engineering 2014
68

Transição de fase no efeito Hall, em camadas de inversão de materiais com gaps estreitos. / Phase transition in the Hall Effect in inversion layers, of materials with narrow gaps.

Marta Silva dos Santos 18 July 1989 (has links)
A Aproximação de Massa Efetiva para a função evnvelope multi-componente, na presença de uma interface, desenvolvida por Marques e Sham, será utilizada aqui, para materiais de gap estreito do grupo II-VI, da seguinte maneira: A) A forte interação entre bandas de condução e valência, nestes materiais, é justificada em um Hamiltoniano de Kane (6x6) modificado, contendo todas as ondas de Bloch propagantes e evanescentes. Na presença de uma interface, a função de onda eletrônica, &#936, é composta de uma onda de Bloch incidente, uma refletida e duas evanescentes, com a mesma energia E e momento paralelo k. Já que a estrutura da maioria dos isolantes utilizados são desconhecidos, a interface semicondutor-isolante por ser considerada como uma barreira infinita, de modo que, &#936, se anule na interface. Existe uma fina região de espessura &#945 na interface, onde o decaimento das ondas evanescentes é indispensável. Distante desta região, as ondas evanescentes possuem um papel insignificante e eventualmente anulam-se. O limite de &#945 &#8594 0 determina as condições de contorno para cada componente da função de onda envelope na interface. B) As condições de contorno são usadas para computar a estrutura de subbandas e o potencial auto-consistente para o Hg1-xCdxTe. A mais interessante característica é o afastamento dos estados de spin duplamente degenerados. Estes resultados serão utilizados para encontrarmos a dependência da energia das subbandas com um campo magnético perpendicular à interface. C) A magneto-condutividade longitudinal é calculada como função do campo magnético B &#8869. Efeitos das interações elétron-elétron e elétrons-impureza são levadas em conta nas aproximações de Hartee-Foch e auto-consistente de Born, respectivamente. Para uma interação elétron-impureza finita, encontram-se fatores de preenchimentos críticos dos níveis de Landau, onde transições de fase são observadas. Estes resultados explicam as descontinuidades presentes, em medidas experimentais, na magneto-resistividade longitudinal e transversal (Hall), em MISFET de Hg (Cd)Te. / The Effective Mass Approximation for multi-component envelope wave function in the presence of an interface in the MOSFET system, developed by Marques and Sham, will be used here, for II-VI narrow-gap semiconductors, in the following way: A) The strong interaction between conduction and valence bands, in these materials, is justified. The (6x6) Kane type modified Hamiltonian is used and the total wave function contains every propagating and evanescent waves. For an interface, the total function, &#936, is composed of one incident and one reflected and two evanescent Bloch waves, with energy E and parallel wave-vector k. Since the band structure of the most used insulators is usually not well known, the insulator-semiconductor interface can be assumed as an infinite barrier; therefore, the total wave-function there can set to zero. The semiconductor evanescent Bloch waves are indispensable in a thin layer, of thickness &#945, close to this region. Far away from the interface their role are insignificant and can be neglected. In the limit &#945 &#8594 0, the boundary condition for each the limit the total Bloch wave function, are derived. B) These boundary conditions are used to calculate the self-consistent electric subband and potential for MISFET of Hg1-xCdxTe. The subbands present a very important spin splitting, due to the internal electric field. C) The effect of a perpendicular magnetic field is also studied and the longitudinal magneto-conductivity are calculated. The effect of electron-electron and electron-impurity interactions are respectively accounted for in the Hartee-Fock and self-consistent Born approximations. For critical electron-impurity interaction, the Landau level filling shows a phase transition at a given fractional occupation (or magnetic field). These results are experimentally observed in both longitudinal and transverse (Hall) magneto-resistance for Hg(Cd)Te.
69

The Effects of Passive Hallux Adduction on Posterior Tibial Artery Blood Flow Compared to the Lateral Plantar Artery

Hatch, Jaysen Alani 23 November 2020 (has links)
Passive hallux adduction has been shown to decrease blood flow in the lateral plantar artery (LPA) in a non-weight-bearing condition. Further research in weight-bearing and shod conditions is necessary to explore relationships between altered blood flow and injury or tissue healing. However, measuring blood flow in a shod foot would require an alternate measurement location to accommodate footwear, such as the more proximal posterior tibial artery (PTA). PURPOSE: To determine changes in blood flow in the PTA and LPA subsequent to passive hallux adduction and to compare the observed changes between the two arteries. Second, to determine if measurement at the PTA is a viable surrogate for measurement at the LPA. METHODS: Forty-one subjects (21 males, 20 females) participated in this study (age 23.5 ± 4.5 years, body mass 72.6 ± 13.7 kg, and height 173.1 ± 10.2 cm). PTA and LPA vessel diameter and velocity were measured via doppler ultrasound (L8-18i transducer GE Logiq S8). LPA was imaged distal to the abductor hallucis and the PTA posterior to the medial malleolus. Each artery was measured for 120 s: 60 s at rest followed by 60 s of passive hallux adduction. PTA and LPA metrics were log transformed and compared using a two-way repeated measures ANOVA, then the log transformed data was assessed with paired t-tests and Bland-Altman plots (alpha = 0.05). RESULTS: There was an expected decrease in blood flow within each artery after passive hallux adduction (p < 0.001). The volume of blood flow differed between the arteries (p < .0001), but the change between baseline to first 5 cardiac cycles after hallux adduction was similar in each artery (p = 0.419). Bland-Altman analysis showed large spread limits of agreement, indicating the PTA underestimated or overestimated measurements at the LPA. CONCLUSIONS: These data suggest that PTA blood flow behaves in a similar manner as LPA blood flow in consequence to passive hallux adduction. There is no significant difference in the absolute change of blood flow during hallux adduction between the LPA and PTA. However, Bland-Altman analysis suggests that the PTA is not a direct surrogate for the LPA due to the large variance in flow between the arteries. Despite this, the PTA can still be a beneficial location of measurement for plantar blood flow. Some reasons are that the PTA has a larger diameter making it an easier artery to image and allows for further research implications due to its ease of access in more applicable circumstances, such as in a shod condition.
70

Nanoplasmonics with Dispersive and Lossy Media

Peck, Ryan 24 May 2022 (has links)
This thesis focuses on the physics of nanoplasmonic systems for dispersive and lossy media. Gold nanoparticles in P3HT (poly(3-hexylthiophene)) and PMMA (poly(methyl methacrylate)) are analyzed both theoretically and experimentally. It is found in both cases that the presence of P3HT narrows the linewidth of the gold plasmon peak. This is a counter-intuitive result, and this narrowing of the linewidth by a lossy material is analyzed in detail. It is found that dispersion in both the real and imaginary parts of the permittivity of the surrounding medium can significantly affect the linewidth. Another plasmonic phenomena was also researched. An atomic energy level model of erbium was constructed and used to solve a rate equation to calculate the far-field emission enhancement from an erbium atom nearby a gold nanorod when the dark mode is excited. Normally a small emission enhancement is expected in the far field since dark modes do not couple strongly to radiation, but in experiments this dark field emission enhancement was seen to be significant. The results of the calculation were compared to this previous experimental result. Although the incident power dependence of the calculated 980 nm emission line agreed with experiments, the 650 nm emission line power dependence and the calculated emission enhancement did not, and so more work needs to be done with this model to explain the experimental results. / Graduate

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