Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16849号 / 工博第3570号 / 新制||工||1539(附属図書館) / 29524 / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 河合 潤, 教授 白井 泰治, 教授 乾 晴行 / 学位規則第4条第1項該当

Silver, gold, and copper metallic nanoparticle films have been utilized in various MEMS devices due to not only their electrical but also their optical properties. The focus of this research is to study the detection at room temperature of carbon monoxide (CO) and hydrogen (H2) via Surface Plasmon Resonance (SPR) phenomenon of silver-embedded Yttrium Stabilized Zirconium (Ag-YSZ) nanocomposite film, gold (Au) nanoparticle film, and an alloy film of silver-copper (Ag-Cu) , grown by the Pulsed Laser Deposition (PLD). To determine the appropriate film materials for quick and accurate CO and H2 detection at room temperature with the PLD technique, the growth process was done repeatedly. Optical tools such as X-Ray Diffraction, Alpha Step 200 Profilometer, Atomic Force Microscopy, and Scanning Electron Microscopy were used to characterize thin films. The gas sensing performance was studied by monitoring the SPR band peak behavior via UV/vis spectrophotometer when the films were exposed to CO and H2 and estimating the percent change in wavelength. The metallic nanoparticle films were tested for concentration of CO (100 to 1000 ppm) and H2 (1 to 10%). Silver based sensors were tested for the cross-selectivity of the gases. Overall the sensors have a detection limit of 100 ppm for CO and show a noticeable signal for H2 in the concentration range as low as 1%. The metallic films show stable sensing over a one-hour period at room temperature. The SPR change by UV/vis spectrophotometer shows a significant shift of 623 nm wavelength between 100 ppm CO gas and dry air at room temperature for the alloy films of Ag-Cu with a wider curve as compared to silver and gold films upon their exposure to CO and H2 indicating an improvement in accuracy and quick response. The results indicate that in research of CO and H2 detection at room temperature, optical gas sensors rather than metal oxide sensors are believed to be effective due to not only the absence of chemical involvement in the process but also the sensitivity improvement and accuracy, much needed characteristics of sensors when dealing with such hazardous gases.

No description available.

The present study addresses some of the problems in human handedness studies by noting the manual choices of one hundred twenty elementary pupils in the first through fifth grades. It discusses the value of the Van Riper critical angle board, the correlation indices of handedness based upon different types of activities, and the divergence with respect to degree and pattern of hand preference in the children.

Neste trabalho apresentamos uma nova técnica para a medida da rotação da polarização da luz por uma substância que possui atividade óptica. O sistema utiliza um LED, dois polarizadores, um prisma de vidro semicilíndrico, uma cubeta, uma CCD e um computador para análise de dados. Luz proveniente do LED passa pelo primeiro polarizador, cujo eixo de transmissão se encontra a 45°, e incide no prisma pelo lado semicilíndrico, ocorrendo reflexão na sua base, num ângulo próximo do ângulo crítico. Devido ao tamanho finito do feixe e o formato curvo da superfície do prisma, vários ângulos de incidência são observados na base da lente semicilíndrica. A luz refletida passa então pela cubeta e depois por um analisador, cujo eixo se encontra paralelo ao primeiro polarizador, e então o sinal é captado pela CCD. De forma alternativa, a cubeta pode ser posicionada após o primeiro polarizador, antes do prisma. Quando a cubeta é preenchida com água, observa-se na CCD uma interferência destrutiva exatamente no ângulo crítico caracterizado por um mínimo de intensidade nesse ângulo. Se uma substância opticamente ativa é utilizada para preencher a cubeta, a posição desse mínimo é alterada dependendo do ângulo de rotação da polarização imposto pela substância. Uma calibração é necessária e pode ser feita utilizando-se soluções de concentração conhecida de sacarose ou frutose, por exemplo. O aparato obtido foi utilizado para medir a rotação causada por uma amostra normal (0,26 g/ml) de soluções de sacarose e frutose e apresenta uma precisão de 0,04°. Equivalentemente, a precisão em concentração é de 0,001 g/ml ou aproximadamente 0,1% (m/m). Isso corresponde a uma precisão que é uma ordem de grandeza acima dos aparelhos comerciais e técnicas mais comuns utilizadas atualmente. Em contrapartida, o custo da montagem experimental é duas ordens de grandeza menor que os mesmos aparelhos comerciais. A produção de uma gama de ângulos de incidência devido à focalização na superfície cilíndrica do prisma substitui a necessidade de se produzir rotação no eixo de polarização do analisador após a passagem da luz pela amostra opticamente ativa, como ocorre em alguns aparelhos comercializados. Este dispositivo, por ser de baixo custo, compacto e de fácil manuseio, é de grande importância porque pode ser utilizado na indústria sucroalcooleira para a medida da quantidade de sacarose em cana e também na indústria farmacêutica para a identificação de substâncias opticamente ativas dextrogiras ou levógiras. / In this thesis we present a novel technique for measuring light polarization rotation caused by an optically active substance. The system is composed by a LED, two polarizers, a semi cylindrical glass prism, a cuvette, a linear CCD camera and a computer for data analysis. Light from the LED passes through the first polarizer, whose transmission axis is set at 45°. After that, the linear polarized light enters the prism by the semi cylindrical face, occurring reflection in the flat face at critical angle approximately. Several incidence angles are accessed due to the beams finite size and the shape of the semi cylindrical lens. The reflected light passes through the cuvette and then through the analyzer, whose transmission axis is set parallel to the first polarizer. Finally, the light is detected by the CCD. When the cuvette is filled up with water, a destructive interference at the critical angle is observed, characterized by a narrow valley centered at this angle. If the cuvette is filled up with an optically active substance, the center of this valley is shifted depending on the substance, its concentration and the optical path travelled by the light in the substance. A calibration is needed and is performed using a set of solutions of known concentrations. Our apparatus was used to measure the angle rotation caused by a normal solution (0,26 g/ml) of sucrose and fructose solutions and has a precision of 0,04°. It corresponds to a precision that is one order of magnitude above most used commercial apparatus and developed techniques. In contrast, the cost of our experimental setup is two orders of magnitude less than the same commercial devices. The production of a range of angles of incidence due to focusing on the cylindrical surface of the prism replaces the need of producing a rotation of the analyzer polarization axis after the light passes through the optically active sample, as it happens in some commercial devices. Since this device has a low cost, is compact and easy to handle, it may be of great importance for applications in the pharmaceutical industry to identify enantiomers, and in the sugar industry for measuring sugar content in sugar cane juice.

Neste trabalho apresentamos uma nova técnica para a medida da rotação da polarização da luz por uma substância que possui atividade óptica. O sistema utiliza um LED, dois polarizadores, um prisma de vidro semicilíndrico, uma cubeta, uma CCD e um computador para análise de dados. Luz proveniente do LED passa pelo primeiro polarizador, cujo eixo de transmissão se encontra a 45°, e incide no prisma pelo lado semicilíndrico, ocorrendo reflexão na sua base, num ângulo próximo do ângulo crítico. Devido ao tamanho finito do feixe e o formato curvo da superfície do prisma, vários ângulos de incidência são observados na base da lente semicilíndrica. A luz refletida passa então pela cubeta e depois por um analisador, cujo eixo se encontra paralelo ao primeiro polarizador, e então o sinal é captado pela CCD. De forma alternativa, a cubeta pode ser posicionada após o primeiro polarizador, antes do prisma. Quando a cubeta é preenchida com água, observa-se na CCD uma interferência destrutiva exatamente no ângulo crítico caracterizado por um mínimo de intensidade nesse ângulo. Se uma substância opticamente ativa é utilizada para preencher a cubeta, a posição desse mínimo é alterada dependendo do ângulo de rotação da polarização imposto pela substância. Uma calibração é necessária e pode ser feita utilizando-se soluções de concentração conhecida de sacarose ou frutose, por exemplo. O aparato obtido foi utilizado para medir a rotação causada por uma amostra normal (0,26 g/ml) de soluções de sacarose e frutose e apresenta uma precisão de 0,04°. Equivalentemente, a precisão em concentração é de 0,001 g/ml ou aproximadamente 0,1% (m/m). Isso corresponde a uma precisão que é uma ordem de grandeza acima dos aparelhos comerciais e técnicas mais comuns utilizadas atualmente. Em contrapartida, o custo da montagem experimental é duas ordens de grandeza menor que os mesmos aparelhos comerciais. A produção de uma gama de ângulos de incidência devido à focalização na superfície cilíndrica do prisma substitui a necessidade de se produzir rotação no eixo de polarização do analisador após a passagem da luz pela amostra opticamente ativa, como ocorre em alguns aparelhos comercializados. Este dispositivo, por ser de baixo custo, compacto e de fácil manuseio, é de grande importância porque pode ser utilizado na indústria sucroalcooleira para a medida da quantidade de sacarose em cana e também na indústria farmacêutica para a identificação de substâncias opticamente ativas dextrogiras ou levógiras. / In this thesis we present a novel technique for measuring light polarization rotation caused by an optically active substance. The system is composed by a LED, two polarizers, a semi cylindrical glass prism, a cuvette, a linear CCD camera and a computer for data analysis. Light from the LED passes through the first polarizer, whose transmission axis is set at 45°. After that, the linear polarized light enters the prism by the semi cylindrical face, occurring reflection in the flat face at critical angle approximately. Several incidence angles are accessed due to the beams finite size and the shape of the semi cylindrical lens. The reflected light passes through the cuvette and then through the analyzer, whose transmission axis is set parallel to the first polarizer. Finally, the light is detected by the CCD. When the cuvette is filled up with water, a destructive interference at the critical angle is observed, characterized by a narrow valley centered at this angle. If the cuvette is filled up with an optically active substance, the center of this valley is shifted depending on the substance, its concentration and the optical path travelled by the light in the substance. A calibration is needed and is performed using a set of solutions of known concentrations. Our apparatus was used to measure the angle rotation caused by a normal solution (0,26 g/ml) of sucrose and fructose solutions and has a precision of 0,04°. It corresponds to a precision that is one order of magnitude above most used commercial apparatus and developed techniques. In contrast, the cost of our experimental setup is two orders of magnitude less than the same commercial devices. The production of a range of angles of incidence due to focusing on the cylindrical surface of the prism replaces the need of producing a rotation of the analyzer polarization axis after the light passes through the optically active sample, as it happens in some commercial devices. Since this device has a low cost, is compact and easy to handle, it may be of great importance for applications in the pharmaceutical industry to identify enantiomers, and in the sugar industry for measuring sugar content in sugar cane juice.

<p dir="ltr">With increasing demand for reduced carbon emissions and increased fuel costs, novel aircraft designs are being developed that reduce the wetted area of the aircraft leading to complex inlet installations for engine integrations. With this, an understanding of the effects of inlet distortion on the compression system is paramount. One key parameter that defines the response of the compression system to inlet distortions is that of the critical angle of distortion. This is the circumferential angle that a distortion must occupy before performance and stability of the compression system is changed. This effort investigates the mechanism by which the critical angle of distortion alters the performance and stability of a high-speed centrifugal compressor. With this, a more accurate estimate of the critical angle of distortion for compressors is developed that allows for characterization of this angle without the need for copious simulations and experimental test campaigns. This investigation was driven by computational fluid dynamic simulations that were utilized to determine the critical angle of inlet distortion. Once this was understood, inlet distortion screens were designed via use of porous inlet-only CFD models to generate similar distortion profiles to those used in the CFD campaign. Finally, these screens were tested and the distortion profiles of the screens investigated along with the performance and stability changes of the compressor due to increasing distortion extents.</p><p dir="ltr">To determine the critical angle of distortion for the centrifugal compressor investigated, a computational fluid dynamics study of the compressor was conducted. In this effort, pure once-per-rev total pressure distortions were delivered to the compression system with the extent varied in terms of number of impeller main blade pitches. The effects of this on performance and machine static pressure rise characteristics was analyzed. These simulations were conducted using a full-annulus transient model to allow for distortion propagation through the passages to be as realistic as possible. The critical angle of distortion of the compressor was found to correspond to 4.5 pitches (or 95.3°) as at this point the compressor efficiency and total pressure ratio were exponentially deteriorated for any increase in distortion extent.</p><p dir="ltr">With knowledge of the critical angle, an understanding of the mechanism by which this alters performance was presented in terms of reduced frequency. Advective, acoustic, and relative acoustic definitions of reduced frequency were analyzed to determine which correlated best with physical flow disturbances from the inlet distortion propagation through the impeller passage. Furthermore, rothalpy was investigated as a tool to track distortion through the passage as it is maintained along a streamline but contains information of the relative frame temporal pressure gradient due to disturbances in the absolute frame. Utilizing distortion tracking and reduced frequencies, the critical angle of inlet distortion was found to correlate with the acoustic reduced frequency. For acoustic reduced frequencies below unity, the compressor performance was degraded.</p><p dir="ltr">With an understanding of the critical extent, inlet-only simulations were conducted to generate designs of total pressure screens to precipitate similar total pressure distortion profiles to the compressor for a design of experiment. These designs were evaluated experimentally using rotatable inlet rakes upstream of the compressor. A comparison between the experimental and CFD data for these distortion profiles showed discrepancies, which were investigated. The findings from this allowed an outline of best practices for future design work for generating total pressure distortion profiles using porous inlet-only models for design of experimental testing of inlet distortion related effects.</p><p dir="ltr">Finally, the centrifugal compressor’s response to the designed inlet distortion screens was analyzed. The compressor was mapped from choke to surge at 80%, 90%, and 100% speed. These corresponded to subsonic, transonic, and supersonic inlet relative Mach numbers for the impeller. The compressor was found to be sensitive above the critical distortion extent with efficiency and stage total pressure ratio degraded. Surge margin was enhanced by use of the screens at 100% speed, but severely degraded at 80% and this was found to correlate with the work characteristic slope. The typical understanding of a more negative work characteristic slope being a more stable operating condition for the compressor was found to be untrue for the distortion screens tested. The compressor entered instability at the same value of work coefficient for all distortion conditions, which lead to a more positive slope of the work characteristic allowing for a wider operating range in terms of flow coefficient.</p>

This diploma thesis is focused on introducing the mathematical and physical fundamentals of viskosity, density and refractive index of liquids and methods of its measurement. Based on available literatures specify review of areas in which the measurement of dynamic viscosity is used for evaluation the actual state of liquid materials. Discuss the possibility of using for example variables to determine the concentration of fat in milk and ethanol in alcoholic beverages. The sample of liquid to realize the practical measurements.