ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper will present techniques for accurately measuring the power flux density (PFD) of interfering signals at telemetry receiving stations. The solar power flux density is measured daily by radio astronomers and will be used as a calibration signal. The electromagnetic spectrum is being used more intensely as time marches on so being familiar with interference measurement techniques is becoming more important because more interfering signals are present.

No description available.

A disponibilidade de água no solo para as culturas é um dos principais fatores de produção. O estudo das características climáticas, juntamente com as propriedades físico-hídricas do solo, o sistema de manejo do agro-ambiente e as características vegetais são itens fundamentais para a implantação de um canavial produtivo. Objetivando caracterizar o comportamento da água no solo e sua influência na produtividade da cana-de-açúcar com e sem adubação nitrogenada, foram instalados instrumentos para medir a entrada e saída da água do solo, permitindo a efetuação do balanço de água em um LATOSSOLO VERMELHO Distrófico típico, localizado na Usina Santa Adélia, Município de Jaboticabal - São Paulo. O estudo foi conduzido em delineamento de blocos casualizados, com 2 tratamentos e 4 repetições, sendo que os tratamentos constaram de uma testemunha - T1 (sem adubação nitrogenada) e T2 (120 kg ha-1 de nitrogênio). As avaliações foram realizadas do dia 30 de setembro de 2005 a 12 de julho de 2006. O volume de controle de utilizado teve como limite inferior a profundidade de 0,90 m, uma vez que essa camada engloba mais de 95 % do sistema radicular da cana-de-açúcar. A precipitação pluviométrica foi medida com um pluviômetro, modelo Paulista, instalado ao lado da área experimental e uma estação meteorológica automática instalada a 500 m da área experimental. As armazenagens de água no solo foram feitas gravimetricamente, nas seguintes camadas: 0 - 0,15; 0,15 - 0,25; 0,25 - 0,35; 0,35 - 0,45; 0,45 - 0,55; 0,55 - 0,65; 0,65 - 0,75; 0,75 - 0,85; 0,85 - 0,95 m; em períodos que variaram de 14 a 28 dias, totalizando 14 amostragens. Para a determinação das densidades de fluxo diárias, no limite inferior do volume de controle de solo, foram instalados tensiômetros nas profundidades de 0,80; 0,90 e 1,0 m, sendo que o tensiômetro de 0,90 m foi utilizado para a estimação da umidade do solo, com uso da curva de retenção da água no solo, e os outros dois tensiômetros para o cálculo do gradiente de potencial total da água no solo. As densidades de fluxo foram calculadas pela equação de Darcy-Buckingham, sendo que a condutividade hidráulica do solo foi determinada pelo método do perfil instantâneo. Conhecendo esses componentes, foi possível efetuar o balanço de água no solo para os 13 períodos, calculando a evapotranspiração pela equação de balanço de massas, uma vez que a pequena declividade permitiu negligenciar o escoamento superficial. As perdas de água por drenagem interna para todo o período não apresentou diferença significativa, enquanto a entrada de água no volume de controle de solo por ascensão capilar foi 87,53 % maior no T2. Esse comportamento das densidades de fluxo nos tratamentos não refletiu em diferença significativa para a armazenagem de água no solo. Ao longo dos 13 períodos avaliados, o T2 apresentou uma evapotranspiração de 1156,06 mm, enquanto no T1 foi de 1057,85. Não se verificou diferença significativa para a produtividade, nem para a eficiência de uso da água da cultura. / The soil water availability for agricultural crops is one of the main production factors. The study of climatic characteristics together with soil physical and hydrological properties, agroenvironmental management system and the plant characteristics are of fundamental importance for the introduction of a productive sugarcane crop. With the objective of characterizing the soilwater behaviour and its influence on the sugarcane productivity, with and without nitrogen fertilization, instruments were installed to measure inputs and outputs of water in the soil, which permitted the determination of the water balance in an Ultisol (Arenic Kandiustults) located in the county of Jaboticabal, State of São Paulo, Brazil. The work was carried out using the experimental design of random blocks, with two treatments and four replications, being the treatments: T1 (control, without nitrogen fertilization), T2 (120 kg ha-1 of nitrogen fertilization). Measurements were made from September 30, 2005 to July 12, 2006. The lower limit of the soil control volume for the water balance was the soil depth if 0.9 m. Rainfall was measured with a raingauge, model ?Paulista? installed beside the experimental area and also by means of an automatic meteorological station installed 500 m from the experimental area. Soil water storages were made gravimetrically in the following soil layers 0 - 0.15 m; 0.15 - 0.25 m; 0.25 - 0.35 m; 0.35 - 0.45 m; 0.45 - 0.55 m; 0.55 - 0.65 m; 0.65 - 0.75 m; 0.75 - 0.85 m; 0.85 - 0.95 m in periods that varied from 14 to 28 days, totalizing 14 samplings. For the dayly water flux density calculations in the lower limit of the control volume, by Darcy-Buckingham equation, tensiometers were installed the 0.80, 0.90 and 1.00 m soil depths, being the tensiometer at the 0.90 m depth used to calculate the soil water content, via a soil water retention curve, and then the soil hydraulic conductivity at this depth, and the other two tensiometers to calculate the soil water total potential gradient at the same depth. The hydraulic conductivity as a function of soil water content was determined by the instantaneous profile method. With the knowledge of these processes of the soil water balance, it was possible to determine the balance for the 13 selected periods, calculating the actual evapotranspiration as the unknown of the soil water balance equation. The small slope of the experimental area permitted to neglect the surface runoff. Internal drainage water losses for the entire period between treatments, were not different, while the water inputs in the control volume by capillary rise was 87.53% higher in treatments T2. This behaviour of the water flux densities in the treatments did not reflect in significant differences for the soil water storage. For the entire evaluated period, treatment T2 presented an evapotranspiration of 1156.06 mm, and treatement T1 of 1057.85 mm. Sugarcane productivity and water use efficiency did not present significant defference between treatments T1 and T2 eventhough plants of treatment T1 were, in average, more efficient in using water.

No description available.

A methodology for the measurement of the radio frequency environment close to the radio noise floor is presented for urban, suburban and rural areas within New Zealand for the purposes of characterisation and trend monitoring by radio spectrum managers. Flux density measurements in bands within a range of frequencies from 80 MHz to 8 GHz have been made in urban, suburban and rural areas of New Zealand during 2007 and 2008. An analysis of the band occupancy is presented in summary form. These summaries are intended as a starting point for radio spectrum usage and can be used as a reference for any future measurements. A description of the computer directories and charts resulting from these measurements, using 20 MHz bandwidths have also been included. All the results for the work have been collated in a set of computer directories named “NZRFI Directories 2007 2008”, which are intended as a reference for use in the determination of local activity in particular frequency ranges. A disc with the full range measurement spectral density charts and channel occupancy charts accompanies this work. Also included on the disc are sets of 20 MHz band charts for some urban, suburban and rural location measurements.

A methodology for the measurement of the radio frequency environment close to the radio noise floor is presented for urban, suburban and rural areas within New Zealand for the purposes of characterisation and trend monitoring by radio spectrum managers. Flux density measurements in bands within a range of frequencies from 80 MHz to 8 GHz have been made in urban, suburban and rural areas of New Zealand during 2007 and 2008. An analysis of the band occupancy is presented in summary form. These summaries are intended as a starting point for radio spectrum usage and can be used as a reference for any future measurements. A description of the computer directories and charts resulting from these measurements, using 20 MHz bandwidths have also been included. All the results for the work have been collated in a set of computer directories named “NZRFI Directories 2007 2008”, which are intended as a reference for use in the determination of local activity in particular frequency ranges. A disc with the full range measurement spectral density charts and channel occupancy charts accompanies this work. Also included on the disc are sets of 20 MHz band charts for some urban, suburban and rural location measurements.

A methodology for the measurement of the radio frequency environment close to the radio noise floor is presented for urban, suburban and rural areas within New Zealand for the purposes of characterisation and trend monitoring by radio spectrum managers. Flux density measurements in bands within a range of frequencies from 80 MHz to 8 GHz have been made in urban, suburban and rural areas of New Zealand during 2007 and 2008. An analysis of the band occupancy is presented in summary form. These summaries are intended as a starting point for radio spectrum usage and can be used as a reference for any future measurements. A description of the computer directories and charts resulting from these measurements, using 20 MHz bandwidths have also been included. All the results for the work have been collated in a set of computer directories named “NZRFI Directories 2007 2008”, which are intended as a reference for use in the determination of local activity in particular frequency ranges. A disc with the full range measurement spectral density charts and channel occupancy charts accompanies this work. Also included on the disc are sets of 20 MHz band charts for some urban, suburban and rural location measurements.

A disponibilidade de água no solo para as culturas é um dos principais fatores de produção. O estudo das características climáticas, juntamente com as propriedades físico-hídricas do solo, o sistema de manejo do agro-ambiente e as características vegetais são itens fundamentais para a implantação de um canavial produtivo. Objetivando caracterizar o comportamento da água no solo e sua influência na produtividade da cana-de-açúcar com e sem adubação nitrogenada, foram instalados instrumentos para medir a entrada e saída da água do solo, permitindo a efetuação do balanço de água em um LATOSSOLO VERMELHO Distrófico típico, localizado na Usina Santa Adélia, Município de Jaboticabal - São Paulo. O estudo foi conduzido em delineamento de blocos casualizados, com 2 tratamentos e 4 repetições, sendo que os tratamentos constaram de uma testemunha - T1 (sem adubação nitrogenada) e T2 (120 kg ha-1 de nitrogênio). As avaliações foram realizadas do dia 30 de setembro de 2005 a 12 de julho de 2006. O volume de controle de utilizado teve como limite inferior a profundidade de 0,90 m, uma vez que essa camada engloba mais de 95 % do sistema radicular da cana-de-açúcar. A precipitação pluviométrica foi medida com um pluviômetro, modelo Paulista, instalado ao lado da área experimental e uma estação meteorológica automática instalada a 500 m da área experimental. As armazenagens de água no solo foram feitas gravimetricamente, nas seguintes camadas: 0 - 0,15; 0,15 - 0,25; 0,25 - 0,35; 0,35 - 0,45; 0,45 - 0,55; 0,55 - 0,65; 0,65 - 0,75; 0,75 - 0,85; 0,85 - 0,95 m; em períodos que variaram de 14 a 28 dias, totalizando 14 amostragens. Para a determinação das densidades de fluxo diárias, no limite inferior do volume de controle de solo, foram instalados tensiômetros nas profundidades de 0,80; 0,90 e 1,0 m, sendo que o tensiômetro de 0,90 m foi utilizado para a estimação da umidade do solo, com uso da curva de retenção da água no solo, e os outros dois tensiômetros para o cálculo do gradiente de potencial total da água no solo. As densidades de fluxo foram calculadas pela equação de Darcy-Buckingham, sendo que a condutividade hidráulica do solo foi determinada pelo método do perfil instantâneo. Conhecendo esses componentes, foi possível efetuar o balanço de água no solo para os 13 períodos, calculando a evapotranspiração pela equação de balanço de massas, uma vez que a pequena declividade permitiu negligenciar o escoamento superficial. As perdas de água por drenagem interna para todo o período não apresentou diferença significativa, enquanto a entrada de água no volume de controle de solo por ascensão capilar foi 87,53 % maior no T2. Esse comportamento das densidades de fluxo nos tratamentos não refletiu em diferença significativa para a armazenagem de água no solo. Ao longo dos 13 períodos avaliados, o T2 apresentou uma evapotranspiração de 1156,06 mm, enquanto no T1 foi de 1057,85. Não se verificou diferença significativa para a produtividade, nem para a eficiência de uso da água da cultura. / The soil water availability for agricultural crops is one of the main production factors. The study of climatic characteristics together with soil physical and hydrological properties, agroenvironmental management system and the plant characteristics are of fundamental importance for the introduction of a productive sugarcane crop. With the objective of characterizing the soilwater behaviour and its influence on the sugarcane productivity, with and without nitrogen fertilization, instruments were installed to measure inputs and outputs of water in the soil, which permitted the determination of the water balance in an Ultisol (Arenic Kandiustults) located in the county of Jaboticabal, State of São Paulo, Brazil. The work was carried out using the experimental design of random blocks, with two treatments and four replications, being the treatments: T1 (control, without nitrogen fertilization), T2 (120 kg ha-1 of nitrogen fertilization). Measurements were made from September 30, 2005 to July 12, 2006. The lower limit of the soil control volume for the water balance was the soil depth if 0.9 m. Rainfall was measured with a raingauge, model ?Paulista? installed beside the experimental area and also by means of an automatic meteorological station installed 500 m from the experimental area. Soil water storages were made gravimetrically in the following soil layers 0 - 0.15 m; 0.15 - 0.25 m; 0.25 - 0.35 m; 0.35 - 0.45 m; 0.45 - 0.55 m; 0.55 - 0.65 m; 0.65 - 0.75 m; 0.75 - 0.85 m; 0.85 - 0.95 m in periods that varied from 14 to 28 days, totalizing 14 samplings. For the dayly water flux density calculations in the lower limit of the control volume, by Darcy-Buckingham equation, tensiometers were installed the 0.80, 0.90 and 1.00 m soil depths, being the tensiometer at the 0.90 m depth used to calculate the soil water content, via a soil water retention curve, and then the soil hydraulic conductivity at this depth, and the other two tensiometers to calculate the soil water total potential gradient at the same depth. The hydraulic conductivity as a function of soil water content was determined by the instantaneous profile method. With the knowledge of these processes of the soil water balance, it was possible to determine the balance for the 13 selected periods, calculating the actual evapotranspiration as the unknown of the soil water balance equation. The small slope of the experimental area permitted to neglect the surface runoff. Internal drainage water losses for the entire period between treatments, were not different, while the water inputs in the control volume by capillary rise was 87.53% higher in treatments T2. This behaviour of the water flux densities in the treatments did not reflect in significant differences for the soil water storage. For the entire evaluated period, treatment T2 presented an evapotranspiration of 1156.06 mm, and treatement T1 of 1057.85 mm. Sugarcane productivity and water use efficiency did not present significant defference between treatments T1 and T2 eventhough plants of treatment T1 were, in average, more efficient in using water.

Geomagnetically Induced Currents (GIC) have been a growing concern within power system operators and researchers as they have been widely reported to lead to power system related issues and material damage to system components like power transformers. In power transformers, GIC impacts are evidenced by part-wave saturation, resulting in transformers experiencing increased presence of odd and even harmonics. The three-phase three-limb (3p3L) transformer has been found to be the most tolerant to high dc values compared to other core types. The research was based on a hypothesis which reads “transformer laboratory testing results can be used as a guide towards developing suitable Finite Element Matrix (FEM) models to be used for conducting GIC/DC experiments”. This study thus investigates the response of a 15 kVA 3p3L laboratory transformer to dc current, emulating the effects of GICs. GIC and dc current are the same under steady state conditions, and hence mentioned interchangeably. Laboratory tests conducted identified two critical saturation points when the transformer is exposed to dc. The early saturation point was identified to be at around 1.8 A/phase of dc (18% of rated current), while the deep saturation point was at around 15 to 20 A/phase of dc (about 72% of rated current). Further analysis showed that holes drilled on the transformer can lower the transformer knee-point by about 26%, depending on the size and location of the holes. The holes hence end up affecting the operating point of the transformer due to losses occurring around the holes. A transformer FEM model was developed following the laboratory exercise, where it was concluded that a 2D model leads to grossly erroneous results, distorting the magnetizing current by about 60% compared to the laboratory results. A solid 3D model improved performance by about 30% as it took the transformer's topological structure into consideration. The 3D model was then refined further to include joints and laminations. It was discovered that laminations on the transformer need to be introduced as stacks of the core, with each core step split into two, allocating a 4% air gap space between stacks. Refinement of the T-joints proved that the joints have a relatively high influence on the transformer behaviour, with their detailed refinement improving the transformer behaviour by about 60%. The final FEM model was used for dc experiments. The results of such experiments showed close resemblance to the laboratory results, with saturation points identified in FEM lying within 10% of the laboratory identified saturation points. Overall, the various investigation methods explored showed that the hypothesis was satisfactorily proven true. Laboratory results functioned as a guide in developing the model, offering a reference case.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23201号 / 工博第4845号 / 新制||工||1757(附属図書館) / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 引原 隆士, 教授 松尾 哲司, 特定教授 中村 武恒 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM