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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.
1

In-situ monitoring of PMMA solution polymerization with dielectric microsensors

Walmet, Eric Robert 12 1900 (has links)
No description available.
2

High-temperature silicon sensors

Hout, S. R. in't. January 1996 (has links)
Thesis (Ph. D.)--Delft University of Technology, 1996. / Includes bibliographical references.
3

High-temperature silicon sensors

Hout, S. R. in't. January 1996 (has links)
Thesis (Ph. D.)--Delft University of Technology, 1996. / Includes bibliographical references.
4

Study of magnetic layers in magnetic sensors

Yuan, Lu. January 1900 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2006. / Title from title screen (site viewed on Feb. 8, 2007). PDF text: vi, 106 p. : ill. (some col.). UMI publication number: AAT 3216416. Includes bibliographical references. Also available in microfilm and microfiche format.
5

Gyroscopes as feedback sensors for position control of a flexible robot arm

Cronjé, Hendrik Albertus 05 February 2014 (has links)
M.Tech. (Electrical Engineering) / The challenges faced by modern industrial robots and robots in general are increasing in cornplexity. A modern robot can be defined as a technological system. capable of replacing or assisting man in carrying out a variety of physical tasks. Thus the implementation of advanced technology in the field of industrial robotics poses different challenges to those faced by engineers in other fields. The reason for this lies mainly in the fact that robots have to be be able to interact with their environment in some intelligent way. For the robot to be able to accomplish this. it must be able to obtain information about its immediate surroundings. and/or its position in the surroundings. In the case of industrial or other stationary robots. the knowledge about its surroundings are of less importance than its own position and the position of the relevant workpieces in the work space. Traditionally the position of a robot arm is measured using position encoders mounted at the joints of the robot arm. The combination of information obtained from these sensors gives the position of the endpoint of the arm. To ensure that the encoder positions accurately reflect the actual position of the arm. the arms have to be rigid, resulting in a heavy. bulky and costly system. If it were possible to determine the endpoint of a robot arm without using the joints of the arm as reference points, it would be possible to design more flexible robot arms. resulting in less costly and more maneuverable systems. Various solutions were considered for this measurement problem and from these it was decided to investigate the use of inertial measurement technology to determine the endpoint position of a flexible robot arm. To test the use of gyroscopes as feedback sensors in the position control of a flexible robot arm. a small low cost robot arm was developed. The design was based on an articulated robot arm with three degrees of freedom (DOF). The system was designed to be fitted with a flexible arm segment to evaluate the gyroscope-based feedback system. The system was further fitted with traditional position sensors to be used as the benchmark against which the gyroscope-based control system was to be compared. Making use of the traditional position sensors the endpoint of the arm can be accurately placed in a space of :3mm x 4mm x 1mni. When the robot was fitted with the flexible arm segment the gyroscopes were able to measure movement of the flexible ann. which the traditional sensors could not detect. Using the gyroscopes as position feedback. the robot was able to track the potentiometer position within 0.19° under dynamic conditions, but under stationary conditions. the error was 6.50 • Based on the results obtained. it was concluded that the displacement of a robot arm segment can be determined using inertial measurement technology. The low cost sensors used proved the concept. but for reliable operation. higher accuracy sensors would be required aided with information obtained from other sensors. i.e, potentiometers resolvers or other absolute encoders.
6

Instrumentation of flexible pavement

Schweiger, Daniel L. January 1995 (has links)
Thesis (M.S.)--Ohio University, June, 1995. / Title from PDF t.p.
7

Avaliação da influência de diferentes tióis no desempenho de biossensores magnetielásticos para detecção de escherichia coli

Pozza, Márcia Dalla 12 December 2016 (has links)
Os métodos de detecção de patógenos, em geral, requerem dias para identificação de micro-organismos patogênicos, havendo interesse em uma detecção rápida e precisa em tempo real, os biossensores magnetoelásticos são uma alternativa promissora. Os sensores magnetoelásticos são dispositivos de detecção que podem ser acessados remotamente e sua aplicação no método de biossensoriamento possui sensibilidade mássica para espécies biológicas, oferecendo confiabilidade na detecção de patógenos como Escherichia coli. Neste trabalho, tiras amorfas Metglas 2826MB3 foram revestidas com Au pelos processos de deposição de sputtering e eletrodeposição e segmentadas em lâminas de 5 x 1 mm. Foram avaliados os parâmetros de rugosidade média absoluta (Ra), desvio padrão das alturas da superfície (Rq) e simetria do perfil de distribuição (Rsk) com a técnica de microscopia de força atômica aplicada em três superfícies distintas (lisa, rugosa e polida). Buscando melhorar a sensibilidade de detecção do dispositivo, avaliou-se a influência de diferentes tióis no desempenho de biossensores magnetoelásticos. Os compostos utilizados diferem no tamanho da cadeia carbônica e no grupamento terminal que liga-se ao anticorpo. Sobre a superfície polida revestida com Cr/Au pelo processo de sputtering depositou-se os compostos cistamina (CYS), cisteamina (CYSTE) e ácido mercaptopropiônico (MPA), seguido por anticorpos. Os biossensores foram expostos a solução de bactéria E. coli e a variação da frequência de ressonância foi medida com um analisador de rede. Foi possível constatar que a superfície polida revestida com Cr/Au pelo processo de sputtering apresentou menores valores de Ra e Rq e melhor perfil de distribuição (Rsk) em relação às demais superfícies estudadas. Os biossensores com o composto MPA mostraram um aumento na captação de bactérias em relação aos biossensores com os compostos CYS e CYSTE, porém altos valores de desvio padrão foram observados, dificultando a reprodutibilidade e confiabilidade do biossensor. Os biossensores testados com CYSTE apresentaram maior eficiência e menor limite de detecção em relação aos biossensores testados com CYS, apontando um melhoramento na utilização deste composto. Os resultados foram favoráveis para a detecção da bactéria E. coli, evidenciando que o tamanho da cadeia carbônica e o grupamento terminal influenciam na eficácia da imobilização deste patógeno em biossensores magnetoelásticos. / Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2016-12-23T12:07:42Z No. of bitstreams: 1 Dissertacao Marcia Dalla Pozza.pdf: 1557950 bytes, checksum: dc75080707940367f6a35094de4afcef (MD5) / Made available in DSpace on 2016-12-23T12:07:42Z (GMT). No. of bitstreams: 1 Dissertacao Marcia Dalla Pozza.pdf: 1557950 bytes, checksum: dc75080707940367f6a35094de4afcef (MD5) Previous issue date: 2016-12-23 / Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq. / The magneto-elastic sensors are detection devices that can be remotely accessed and applied as biosensors having a mass sensitivity for detection of biological specimens, offering reliability in the detection of pathogens such as Escherichia coli. The pathogen detection methods generally require days to identify the pathogenic micro-organism, so there is interest in a rapid and accurate detection in real time. The magneto elastic biosensors are a promising alternative for this task. In this work, amorphous ribbons of Metglas 2826MB3 were coated with Au by the processes of sputtering and electrodeposition and segmented into 5 x 1 mm strips. We evaluated the roughness parameters arithmetic average height (Ra), root mean square roughness (Rq) and skewness (Rsk) using atomic force microscopy applied on three different surfaces (smooth, rough and polished). Seeking to improve the detection sensitivity of the device, the performance of the biosensors was evaluated in terms of the effects of different thiols on their performance. The compounds used differ in the size of the carbon chain and the terminal grouping which binds to the antibody. On the polished surface coated with Cr/Au by sputtering, we deposited the compounds cystamine (CYS), mercaptopropionic acid (MPA) and cysteamine (CYSTE), followed by antibodies. The biosensors were exposed to the bacteria E. coli in solution and the variation of the resonance frequency was measured with a network analyzer. It was found that the polished surface coated with Cr/Au by sputtering process showed lower values of Ra and Rq and a better distribution profile (Rsk) in relation to other surface studied. Biosensors employing the compound MPA showed an increase in attracting bacteria in relation to biosensors with CYS and CYSTE, but high standard deviations were observed, thus hampering the reproducibility and reliability of the biosensor. Biosensors tested with CYSTE showed higher efficiency and lower detection limit with respect to biosensors tested with CYS, indicating an improvement in the use of this compound. The results were favorable for the detection of E. coli, indicating that the size of carbon chain and the terminal grouping influence the effectiveness of immobilization of the magneto elastic biosensors.
8

Avaliação da influência de diferentes tióis no desempenho de biossensores magnetielásticos para detecção de escherichia coli

Pozza, Márcia Dalla 12 December 2016 (has links)
Os métodos de detecção de patógenos, em geral, requerem dias para identificação de micro-organismos patogênicos, havendo interesse em uma detecção rápida e precisa em tempo real, os biossensores magnetoelásticos são uma alternativa promissora. Os sensores magnetoelásticos são dispositivos de detecção que podem ser acessados remotamente e sua aplicação no método de biossensoriamento possui sensibilidade mássica para espécies biológicas, oferecendo confiabilidade na detecção de patógenos como Escherichia coli. Neste trabalho, tiras amorfas Metglas 2826MB3 foram revestidas com Au pelos processos de deposição de sputtering e eletrodeposição e segmentadas em lâminas de 5 x 1 mm. Foram avaliados os parâmetros de rugosidade média absoluta (Ra), desvio padrão das alturas da superfície (Rq) e simetria do perfil de distribuição (Rsk) com a técnica de microscopia de força atômica aplicada em três superfícies distintas (lisa, rugosa e polida). Buscando melhorar a sensibilidade de detecção do dispositivo, avaliou-se a influência de diferentes tióis no desempenho de biossensores magnetoelásticos. Os compostos utilizados diferem no tamanho da cadeia carbônica e no grupamento terminal que liga-se ao anticorpo. Sobre a superfície polida revestida com Cr/Au pelo processo de sputtering depositou-se os compostos cistamina (CYS), cisteamina (CYSTE) e ácido mercaptopropiônico (MPA), seguido por anticorpos. Os biossensores foram expostos a solução de bactéria E. coli e a variação da frequência de ressonância foi medida com um analisador de rede. Foi possível constatar que a superfície polida revestida com Cr/Au pelo processo de sputtering apresentou menores valores de Ra e Rq e melhor perfil de distribuição (Rsk) em relação às demais superfícies estudadas. Os biossensores com o composto MPA mostraram um aumento na captação de bactérias em relação aos biossensores com os compostos CYS e CYSTE, porém altos valores de desvio padrão foram observados, dificultando a reprodutibilidade e confiabilidade do biossensor. Os biossensores testados com CYSTE apresentaram maior eficiência e menor limite de detecção em relação aos biossensores testados com CYS, apontando um melhoramento na utilização deste composto. Os resultados foram favoráveis para a detecção da bactéria E. coli, evidenciando que o tamanho da cadeia carbônica e o grupamento terminal influenciam na eficácia da imobilização deste patógeno em biossensores magnetoelásticos. / Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq. / The magneto-elastic sensors are detection devices that can be remotely accessed and applied as biosensors having a mass sensitivity for detection of biological specimens, offering reliability in the detection of pathogens such as Escherichia coli. The pathogen detection methods generally require days to identify the pathogenic micro-organism, so there is interest in a rapid and accurate detection in real time. The magneto elastic biosensors are a promising alternative for this task. In this work, amorphous ribbons of Metglas 2826MB3 were coated with Au by the processes of sputtering and electrodeposition and segmented into 5 x 1 mm strips. We evaluated the roughness parameters arithmetic average height (Ra), root mean square roughness (Rq) and skewness (Rsk) using atomic force microscopy applied on three different surfaces (smooth, rough and polished). Seeking to improve the detection sensitivity of the device, the performance of the biosensors was evaluated in terms of the effects of different thiols on their performance. The compounds used differ in the size of the carbon chain and the terminal grouping which binds to the antibody. On the polished surface coated with Cr/Au by sputtering, we deposited the compounds cystamine (CYS), mercaptopropionic acid (MPA) and cysteamine (CYSTE), followed by antibodies. The biosensors were exposed to the bacteria E. coli in solution and the variation of the resonance frequency was measured with a network analyzer. It was found that the polished surface coated with Cr/Au by sputtering process showed lower values of Ra and Rq and a better distribution profile (Rsk) in relation to other surface studied. Biosensors employing the compound MPA showed an increase in attracting bacteria in relation to biosensors with CYS and CYSTE, but high standard deviations were observed, thus hampering the reproducibility and reliability of the biosensor. Biosensors tested with CYSTE showed higher efficiency and lower detection limit with respect to biosensors tested with CYS, indicating an improvement in the use of this compound. The results were favorable for the detection of E. coli, indicating that the size of carbon chain and the terminal grouping influence the effectiveness of immobilization of the magneto elastic biosensors.
9

Karakterisering van makroskopiese oppervlakgrofheid met behulp van akoestiese golwe

Blom, C. 29 September 2014 (has links)
M.Ing. (Electrical & Electronic Engineering) / Please refer to full text to view abstract
10

Low differential pressure and multiphase flow measurements by means of differential pressure devices

Ruiz, Justo Hernandez. January 1900 (has links)
Thesis (Ph.D.)--Texas A & M University, 2004. / Title from caption (viewed on Feb. 8, 2008). Title from document title page. Includes bibliographical references. Available in PDF format via the World Wide Web.

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