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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.
361

Alternative power transfer for passive RFID systems in challenging applications

Yang, Shuai January 2018 (has links)
This dissertation presents a case study which attempts to implement a passive Ultra High Frequency Radio Frequency Identification (UHF RFID) system on aircraft landing gear (LG) to permit component configuration management. It is shown that a monostatic RFID system with two reader antennas, one on the LG main fitting and one in the wing bay allows up to 64 kbits of data to be associated with each LG component. A 7 dB system margin allows data on each LG component to be updated wirelessly and will also enable a passive UHF RFID-based LG health and usage monitoring system when tags with required sensors become available. Results from an electromagnetic simulation show that when a metal is illuminated by a nearby antenna the E-field distribution close to its surface is stronger than in free space. To explore if the stronger E-field can be used to enhance the performance of a conventional passive tag, a 5 cm × 6 mm × 3.02 m aluminium bar has been selected as the tagging object and connected to the reader via an RF feed. It is shown that a conventional metal tag which has a maximum free space range of 1.3 m when mounted on a metal plate can be detected up to 30 m along the aluminium bar from the RF feed. When orientated with the long axis normal to the metal surface a conventional passive tag with a dipole antenna can efficiently harvest the E- field and can be read at least 50 m away from the antenna feed. The proposed use of metal objects as a nearfield antenna is well suited to some applications, but in others a significant wireless path is still required. In such a case, a semi-passive tag can be used. It is demonstrated that a semi-passive tag only requires 14.4 ̧œ‡̧‘Š to be read over 42 m in a bistatic RFID system. Such a power consumption can be easily achieved by most energy harvesting techniques. It is demonstrated that a solar-powered semi-passive tag can be read at a range of 22 m, but its performance is still limited by multipath effects. A distributed antenna system (DAS) can be used to overcome these effects by using frequency and phase hopping techniques. It is demonstrated that 50 solar-powered semi-passive tags can be read with no missed detections over a 10 m × 20 m office area with 4 dB system margin.
362

Changes in microvascular hematocrit during post-occlusive reactive hyperemia: descriptions and mechanisms

Bopp, Christopher Michael January 1900 (has links)
Doctor of Philosophy / Department of Anatomy and Physiology / Thomas J. Barstow / The primary aim of this dissertation was to describe the changes in microvascular hematocrit, as total[hemoglobin+myoglobin] (T[Hb+Mb] measured with near-infrared spectroscopy (NIRS), during post-occlusive reactive hyperemia (PORH). Mechanisms of reactive hyperemia within skeletal muscle were also explored. The investigation detailed in Chapter 2 of this dissertation found that the differing time courses of the kinetic responses of both oxy- and deoxy[Hb+Mb], are related to changes in T[Hb+Mb]. We also determined that adipose tissue thickness had no effect on a purely temporal analysis of NIRS data. In Chapter 3 we observed that brachial artery reactive hyperemia preceded changes in T[Hb+Mb] during reactive hyperemia. Assuming that myoglobin remained constant, we posited that changes in T[Hb+Mb] must reflect alterations in red blood cell concentration in the microvasculature, i.e., microvascular hematocrit. In Chapter 4 comparisons were made between brachial artery blood flow, cutaneous and skeletal muscle flux and T[Hb+Mb]. The conduit artery response was faster than the microvascular responses in all tissues. Within skeletal muscle, time to peak and the time constant for the on-kinetics were faster in T[Hb+Mb] compoared with intramuscular flux as measured with intramuscular laser-Doppler. We observed no differences in temporal responses between cutaneous and intramuscular measures and suggested that in a purely temporal analysis the cutaneous microvasculature could serve as an analog for the skeletal muscle microvasculature. Finally, in Chapter 5 we found that prostaglandin inhibition with ibuprofen altered the initial T[Hb+Mb] response during PORH without impacting cutaneous flux or brachial artery blood flow. Chapter 5 also discussed that the addition of a wrist cuff to our standard instrumentation prevented the accumulation of T[Hb+Mb] during the occlusion period.
363

Development of NIR spectroscopy models for starch content prediction and ethanol production from mutant grain sorghum

Saul, Kaelin E. January 1900 (has links)
Master of Science / Biological & Agricultural Engineering / Donghai Wang / The growing demands for renewable energy sources have led researchers to investigate other biomass sources, aside from maize. Grain sorghum is comparable to maize in its starch content and can be grown in regions with drier climates, where maize is a less suitable crop for these areas. In attempts to increase yield prior to harvest and for ethanol production, this study focuses on mutant grain sorghum. One hundred and nine mutant grain sorghum samples were analyzed for their chemical and physical properties and fermented into ethanol. The current method for starch analysis is time-consuming and tedious. Near infrared spectroscopy (NIR) models were developed as fast, cost-effective, and non-destructive methods for grain sorghum starch content analysis. Each mutated grain sorghum sample was scanned in a wavelength range from 4,000 to 10,000 cmˉ¹ as a whole grain and in flour form. Partial Least Squares (PLS) regression method was used for NIR model development. The coefficients of determination (R²) of 0.77 and 0.90 were achieved for starch content calibration and prediction models, respectively. This model demonstrates the possibility of a positive correlation between the actual and calculated values for starch content. Another PLS first derivative model with R² = 0.95 for calibration and a reduced wavelength range (4,000-5,176 cmˉ¹), using 39 of the original 109 samples (27 for calibration and 8 for validation), was created to predict the fermentation efficiency.
364

Desenvolvimento de um analisador de processo por espectroscopia no infravermelho próximo (NIR) para previsão de propriedades de derivados de petróleo / Development of a near-infrared process analyzer for the prediction of properties of petroleum products

Bueno, Aerenton Ferreira 18 August 2018 (has links)
Orientador: Célio Pasquini / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-18T09:40:06Z (GMT). No. of bitstreams: 1 Bueno_AerentonFerreira_D.pdf: 13715052 bytes, checksum: 49ac649190d25c5991f45b0564f4df65 (MD5) Previous issue date: 2011 / Resumo: O trabalho trata do desenvolvimento de um analisador de processo utilizando a espectroscopia no infravermelho próximo (NIR) para prever propriedades de derivados de petróleo, como gasolina e querosene de aviação. O instrumento foi projetado para ser instalado diretamente em uma linha de processo numa unidade industrial, realizando, de maneira automatizada, a coleta, análise e descarte da amostra, envio dos resultados obtidos, além de operações como limpeza da célula e diagnósticos funcionais. Um protótipo de um espectrofotômetro NIR de bancada foi construído, a partir do qual, foi montado um espectrofotômetro de laboratório plenamente funcional. O espectrofotômetro foi instalado num gabinete com sistema de pressurização (para estar de acordo com a classificação da área industrial), controlador de temperatura e dispositivos para a seleção da amostra e limpeza da célula, tornando-se, assim, um analisador de processo. Um programa de computador em linguagem Visual Basic foi desenvolvido para a operação automatizada do analisador. Foram obtidos espectros e desenvolvidos modelos de calibração multivariados para prever uma série de parâmetros de qualidade de gasolina (como destilação, octanagem e concentrações de aromáticos, olefinas e saturados) e querosene de aviação (massa específica e ponto de congelamento), que apresentaram resultados compatíveis com os valores de precisão dos métodos de referência utilizados. O analisador foi instalado num sistema de mistura para produção de gasolina de uma refinaria de petróleo, visando prever, em tempo real, vários parâmetros de qualidade desse produto, para a otimização do processo produtivo / Abstract: The work deals with the development of a process analyzer using near infrared spectroscopy (NIR) to predict properties of petroleum products like gasoline and jet fuel. The instrument was designed to be mounted directly on a line in an industrial process, performing automatically the collection, analysis and disposal of the sample, transmission of results, as well as operations such as cleaning the cell and functional diagnosis. A prototype of a benchtop NIR spectrometer was built, from which a fully functional laboratory spectrophotometer was assembled. The spectrophotometer was installed in a cabinet with a pressurization system (to be consistent with the classification of the industrial area), temperature controller and devices for sample selection and cleaning of the cell, becoming thus a process analyzer. A computer program written in Visual Basic was developed for the automated operation of the analyzer. Spectra were acquired and multivariate calibration models were developed to predict a series of gasoline (such as distillation, octane and concentrations of aromatics, olefins and saturated) and jet fuel quality parameters (specific gravity and freezing point), who presented results compatible with the precision values of the reference methods used. The analyzer was installed in a blending system for production of gasoline in an oil refinery, aimed to provide, in real time, various quality parameters of the product, to optimize the production process / Doutorado / Quimica Analitica / Doutor em Ciências
365

Determinação dos parametros de qualidade de detergentes em po utilizando espectroscopia no infravermelho proximo / Determination of the parameters of quality of powder detergents using near infrared spectroscopy

Povia, Giovana Soato 30 May 2007 (has links)
Orientador: Celio Pasquini / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-09T09:59:17Z (GMT). No. of bitstreams: 1 Povia_GiovanaSoato_M.pdf: 1681817 bytes, checksum: d59818d169390e4a42e0555251507c27 (MD5) Previous issue date: 2007 / Resumo: Este trabalho visa o desenvolvimento de um método analítico para a determinação dos parâmetros de qualidade em detergentes em pó utilizando a Espectroscopia de Infravermelho Próximo (NIR) e técnicas de calibração multivariada. Foram utilizados dois conjuntos de amostras: o primeiro para as análises quantitativas e o segundo para análises qualitativas. As amostras do primeiro conjunto tiveram os parâmetros de qualidade determinados pelos respectivos métodos de referência. A técnica estatística utilizada para as calibrações foi o PLS. Foram desenvolvidos modelos de calibrações para a previsão do teor de umidade, matéria ativa e densidade. O desempenho dos modelos de calibrações foi avaliado por meio de validação externa. A determinação do teor de umidade apresentou RMSEP = 0,29% (m/m). O valor de RMSEP para a determinação da matéria ativa foi de 0,37% (m/m) e para a determinação da densidade o valor de RMSEP = 14 g L . Os modelos construídos apresentaram resultados satisfatórios e os erros encontrados são aceitáveis para a faixa de controle utilizada na indústria. O segundo conjunto é composto de 4 grupos, que apresentam características distintas. Foram avaliados dois métodos de classificação: SIMCA e PLS DA. É possível observar que ocorre a discriminação das amostras que apresentam teor de matéria ativa mais elevado, no entanto, os outros grupos não puderam ser discriminados. Os dois métodos de classificação avaliados apresentaram resultados semelhantes, com acerto de 100% na classificação de amostras externas somente em seus respectivos grupos / Abstract: This work aims the development of an analytical method for the determination of quality parameters on powder detergents using the near infrared spectroscopy (NIR) and multivariate calibration techniques. Two sets of samples were used: the first one for the quantitative analysis and the second one for qualitative analysis. The samples of the first set had the quality parameters determined by their respective methods of reference. The chemometric technique used for calibration was the PLS1. Calibrations for the prediction of de moisture content, active matter and density were developed. The performance of the calibration models was evaluated through external validation. The determination of the moisture content presented a RMSEP = 0,29% (w/w). The value of RMSEP for the determination of the active matter was 0,37% (w/w) and for the determination of moisture the value of RMSEP was 14 g L. The constructed models presented satisfactory results and the errors that were found are acceptable for the control range used in industry. The second set is composed of four groups of power detergents which present different characteristics. Two methods of classification were evaluated: SIMCA and PLS DA. It was possible to observe the discrimination of the samples which presents higher active matter content. However, the other groups could not be discriminated. Both methods of classifications evaluated presented similar results, with 100% correcte results of the classification of samples only in their respective groups / Mestrado / Quimica Analitica / Mestre em Química
366

Espectroscopia de infravermelho-próximo em madeiras neotropicais: aplicação na identificação e predição de propriedades físicas / Near-infrared spectroscopy in neotropical woods: application to identification and prediction of physical properties

Raphael Jaquier Bossler Pigozzo 06 May 2011 (has links)
A madeira é uma excelente matéria-prima renovável, sendo empregada como fonte de celulose e na construção civil, e sendo usada ainda como combustível. Contudo, as propriedades da madeira variam muito entre as espécies. Logo, saber a qual espécie pertence a madeira, assim como algumas de suas propriedades é essencial para um planejamento adequado de sua aplicação, evitando desperdícios e melhorando a qualidade dos produtos derivados do material. No presente estudo, analisou-se a aplicação da espectroscopia de infravermelho-próximo (NIR) na identificação e predição de propriedades físicas de madeiras nativas ou plantadas no Brasil, as quais apresentam grande variação entre suas propriedades e características anatômicas. Primeiramente, foi verificada a relação do espectro NIR com a densidade básica e algumas das características anatômicas importantes para identificação de madeiras, em especial aquelas ligadas aos raios parênquimáticos. Em seguida, com a espectroscopia NIR, foram desenvolvidos modelos para predição da densidade básica em madeiras de várias espécies brasileiras. Por fim, aplicou-se a espectroscopia NIR para discriminação entre as madeiras de Dalbergia nigra e D. spruceana, as quais são muito semelhantes em aspecto e características anatômicas. Os resultados sugerem que a espectroscopia de infravermelho-próximo é uma potencial ferramenta para classificação das diferentes madeiras brasileiras de acordo com suas propriedades físicas. Os resultados sugerem ainda uma metodologia auxiliar no processo de identificação pela anatomia do lenho. / Wood is an excellent renewable raw material, used as fuel, pulp and as building material. However, the properties of wood vary widely among species. Therefore, knowing the wood species as well as some of its properties is essential for proper planning of its application, avoiding waste and improving the quality of wood based products. In this study it was analysed the application of the near infrared spectroscopy (NIR) to identification and prediction of physical properties of native or planted timbers from Brazil, which show great variation on their properties and anatomical features. First, it was verified the relationship between the NIR spectrum and the basic density as well as some important anatomical features for wood identification, especially those related to ray parenchyma. Then, using NIR spectroscopy, models were developed to predict the wood basic density from various Brazilian species. It was also applied NIR spectroscopy to separate the woods from Dalbergia nigra and D. spruceana, two woods that are very similar in appearance and anatomical features. The results suggest that near-infrared spectroscopy is a potential tool for classification of various Brazilian woods based on their physical properties, as well as an auxiliary method in wood anatomy identification.
367

Estratégias quimiométricas aplicadas ao estudo de imagens químicas : novas possibilidades para caracterização de produtos e processos farmacêuticos / Chemometric strategies applied to the study of chemical imaging : new possibilities for the characterization of pharmaceutical products and processes

Sabin, Guilherme Post, 1977- 03 November 2013 (has links)
Orientador: Ronei Jesus Poppi / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-22T17:44:22Z (GMT). No. of bitstreams: 1 Sabin_GuilhermePost_D.pdf: 9789223 bytes, checksum: 0f451c3cf56a345b71358f196448c6d9 (MD5) Previous issue date: 2013 / Resumo: A indústria farmacêutica está em constante busca por novas tecnologias analíticas capazes de fornecer informações relevantes sobre produtos e processos industriais. Esta tese sugere novas possibilidades no estudo de medicamentos através de imagens químicas obtidas por microespectroscopia na região do infravermelho próximo e as seguintes ferramentas quimiométricas: MLR, CLS, MCR e PLS. Os trabalhos estão divididos em quatro tópicos e contribuem para o avanço analítico neste campo de conhecimento. Na primeira aplicação, foi realizado um estudo da similaridade entre imagens obtidas por técnicas quimiométricas distintas. O trabalho mostra como estimar limites de confiabilidade para a concentração por pixel de imagem. Assim, foi possível diminuir o tempo de aquisição de imagens mantendo a confiabilidade analítica no estudo de comprimidos de carbamazepina. O segundo estudo mostra uma aplicação onde a vantagem de segunda ordem foi requerida. Este estudo traz uma abordagem nova sobre o reconhecimento de padrões de imagem na caracterização de produtos farmacêuticos. Na terceira aplicação, o objetivo foi acompanhar o desenvolvimento industrial de um produto farmacêutico com baixo teor de ativo, auxiliando no processo de decisão em termos de micro-homogeneidade da formulação. O estudo mostrou que a concentração local pode ser explorada como vantagem analítica. Na quarta aplicação, foi abordado pela primeira vez na literatura, o estudo da estrutura de pellets farmacêuticos através de informações químicas obtidas por espectroscopia de imagem química na região do infravermelho próximo. Este trabalho abre alternativas para o estudo de medicamentos de entrega controlada. / Abstract: The pharmaceutical industry is constantly searching for new analytical technologies capable of providing relevant information about products and industrial processes. This thesis suggests new possibilities in the study of drugs by using chemical images obtained by microspectroscopy in the near infrared region and the following chemometric tools: MLR, CLS, MCR e PLS. The work is divided into four topics and it contributes to the advancement in the field of analytical knowledge. In the first application, a study was performed about the similarity between images obtained by different chemometric techniques. The work demonstrates how to estimate concentration reliability limits per image pixel. Thus, it was possible to shorten the time of image acquisition while maintaining analytical reliability in the study of carbamazepine tablets. The second study presents an application where the advantage of the second order was required. This study presents a new approach to the recognition of image patterns in the characterization of pharmaceuticals. In the third application, the aim was to follow the industrial development of a pharmaceutical product with a low active content, assisting in the decision about the process in terms of micro-homogeneity of the formulation. The study showed that the local concentration can be exploited for analytical advantage. In the fourth application, addressed in a publication for the first time, is the study of the structure of pharmaceutical pellets through chemical information obtained by near infrared chemical imaging. This work opens up alternatives for the study of controlled delivery drugs. / Doutorado / Quimica Analitica / Doutor em Ciências
368

Fire and water must live together: a novella

Gabbard, Robert January 1900 (has links)
Master of Arts / Department of English / Katherine Karlin / By the year 2037, climate change has destabilized the world’s ecology, politics, and culture. Hawaii has seceded from the United States, instituting the Cultural Reaffirmation, which champions a sustainable, traditional way of life. Eenie is an astronomer on the Big Island of Hawaii. In order to keep the observatory on Mauna Kea operational, she must appease the newly independent island nation by reenacting a mythical sled race between Poliahu, the Hawaiian snow goddess of Maunakea, and Pele, the fierce goddess of lava, personified by a rival geoscientist from Maunaloa’s volcanic laboratory. Once an Olympic contender in the women’s luge, Eenie has won this race twice before. This year, though, the greenhouse effect has caught up with her; there is no snow on Maunakea. Without it, she cannot prevail, and if she doesn’t, the priests of Hawaii’s Cultural Reaffirmation will pull the telescopes down from their most sacred mountain. Eenie struggles against nature’s increasing wrath, gods, monsters, pigs, and political rivals, though her biggest struggle is within herself. Fire and water must live together takes place in an ecodystopic future, though its story pulls from Hawaiian myth. The story’s projection into the future is based on current events, including the Hawaiian sovereignty movement, climate change science, and technology. An accompanying essay frames the novella through three critical lenses: ecocriticism, eco-politics, and post-colonial hybridity. The essay includes a focused look at the setting of Hawaii as it stands today in terms of environment, politics, and people.
369

Consistency of near-infrared spectroscopy chromophores during a 10-minute vascular occlusion procedure of the thigh over 5 consecutive days

Mackintosh, Cameron Eve 07 July 2016 (has links)
The purpose of this study was to examine the consistency of near-infrared spectroscopy (NIRS) measures associated with a 10 minute vascular occlusion of the thigh during 5 consecutive days. A secondary purpose was to examine if the repeated daily occlusions modify the vascular response to such occlusions. The NIRS chromophores of oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (HHb), total hemoglobin (tHb), hemoglobin difference (HbDiff), and total saturation index (TSI) were monitored at the vastus lateralis muscle during each testing session. Participants were female (age 18-30 yrs) and were randomly assigned to one of two groups. The Test Group (age 23 ± 2yrs) completed an occlusion test every day for 5 consecutive days while the Control Group (age 21 ±1.6yrs) was tested on days 1, 3 and 5. Each testing session involved 10 minutes rest in a supine position, 10 minutes of femoral artery occlusion (preset at 250mmHg), 10 minutes of recovery. At onset of occlusion, the rapid cuff inflation system inflated in 0.3 seconds to the preset 250mmHg. Following the 10 minutes of occlusion, the cuff was deflated in 0.3 seconds. Heart rate was monitored throughout all testing sessions and mean arterial pressure was calculated and compared between groups. There were no significant group or day main effects found, nor any significant interactions for the following hemoglobin chromophores measures: HbO2, HHb, HbDiff, and TSI. In all participants, the NIRS response pattern to rest, occlusion and recovery was consistent for all testing days regardless of group. The response pattern to the occlusion initiated by the rapid cuff inflation was as follows: HbO2, tHb, HbDiff, and TSI decreased then slowly plateaued over the 10 minutes while HHb increased initially and then plateaued. Following the rapid cuff deflation, HbO2, tHb, HbDiff and TSI increased to their maximum reperfusion levels and then plateaued over the remainder of the 10 minutes of recovery. During that same period, HHb decreased initially upon reperfusion and then plateaued. Unlike the other measures, TSI and tHb demonstrated inconsistencies in their response pattern regardless of group or day. The consistency of hemoglobin chromophores response pattern to daily 10 minute vascular leg occlusions over 5 consecutive days is an important finding of this study. This response indicates that there is no apparent change in vascular response to repeated occlusions and has implications for exercise studies that use occlusion in their methodology. The study also emphasizes the inconsistency of tHb and TSI as primary hemoglobin response measures to occlusion. Similarly, the results demonstrate the potential misinterpretation of results if only relying on one hemoglobin measure during occlusion. / Graduate
370

Teachers' Experiences with the Teaching Proficiency Through Reading and Storytelling (TPRS) Method of Language Instruction| A Qualitative Study Using a Quasi-Phenomenological Approach

Baker, Richard J. 27 September 2017 (has links)
<p> This quasi-phenomenological study identified the common lived classroom experiences of high school (grades 9-12) teachers who used the Teaching Proficiency through Reading and Storytelling (TPRS) method of world language instruction. The study also explained why some teachers who were trained in and had some experience using TPRS abandoned the method, and what they perceived as obstacles to its use. Additionally, the study identified the techniques perceived as effective by traditional teachers for promoting student success in producing and comprehending the target language with the goal of bridging the gap between TPRS and non-TPRS teachers.</p><p> The central phenomenon studied was teachers&rsquo; lived experiences using TPRS, a method of world language teaching for providing a near-immersion classroom learning experience. The TPRS method required no textbook or grammar syllabus and focused on providing students with interesting, repetitive, and comprehensible input of commonly used verb structures and high-frequency vocabulary within the context of a story. For this study, a non-TPRS traditional approach included using a textbook, a grammatical syllabus, and production-based communicative classroom learning activities.</p><p> A purposeful sample of study participants included three groups of ten teachers each. The first two groups constituted the phenomenological part of the study because they had training and experience with TPRS. In the first group, ten participants used TPRS and considered themselves primarily as TPRS teachers. In a second group, ten teachers were selected because they were trained in TPRS and had some experience using the method but discontinued or limited its use when they encountered obstacles and resistance. A third group, not part of the phenomenological portion of the study, consisted of ten teachers who were not trained in TPRS, used a traditional approach, and had no experience using the method. That group provided a perspective outside of TPRS training and experience to discover which teaching techniques they perceived as effective. That input was included in the study to inform the researcher of potential improvements to recommend for the continuously developing TPRS method.</p><p> Data were collected through in depth, face-to-face, in-person, open-ended, semi-structured interviews. The results of the data analysis identified sixteen common lived experiences of TPRS teachers, twelve obstacles encountered by teachers when using or trying out TPRS, and four recommendations to consider incorporating into this changing and evolving method of world language instruction. </p><p>

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