The achievable accuracy of hygrothermal building component simulation is significantly dependent on the applied material functions. These functions are determined by the material modelling marking the connection between the basic storage and transport parameters which are obtained from basic measurements, and the storage and transport coefficients which are defined within the balance and flow equations. It is the aim of the present study to develop a flexible and widely applicable material model which is not restricted to the current level of the transport theory. Furthermore, limits and options of this model are to be validated by means of four building materials on the basis of special transient moisture profile measurements. The study’s starting point is a comprehensive investigation of both, the different existing modelling approaches and the available experimental methods to determine basic hygrothermal material parameters. On this basis, the material modelling is set into the context of the heat and moisture transport theory derived from thermodynamics. The involved limits and restrictions are highlighted and options as well as requirements for further developments are pointed out. The developments this study focuses on comprise three fields: experiments for basic property determination, material modelling, and experiments for material model validation. The set of basic material investigation methods has been extended by the drying experiment under defined conditions. The different influences on the drying as well as its application to hygrothermal material model calibration are pointed out and appraised. On this basis, a drying apparatus is designed, built and applied. Ultimately, standardisation criteria and the derivation of a single-value drying coefficient are evaluated. Appropriate extensions are indicated. Based on the bundle of tubes approach, an own material model is developed. It is coupled with a mechanistical approach accounting for serial and parallel structured moisture transport phenomena. The derived liquid water conductivity is adjusted by the help of measured conductivity data close to saturation as well as within the hygroscopic moisture range. Subsequently, two internal modelling parameters are calibrated which is done by numerical simulation of the water uptake and the drying experiment under consideration of the hysteresis of moisture storage. Facilitating its application to the obtained laboratory data, the material model has been implemented into a computer program. It is applied to the four building materials brick, lime-sand brick, aerated concrete and calcium silicate. The adjusted material functions are shown and discussed. In all four cases, the calibration provides an excellent agreement between measured and calculated material behaviour. As experimental basis of the material model validation, the instantaneous profile measurement technique (IPM) has been extended to be applied in Building Physics. Special equipment is developed and measurement procedures are designed. Different models to derive the water content from dielectric data obtained by Time Domain Reflectometry (TDR) measurements are evaluated and implemented. Ultimately, an extensive program of transient moisture profile measurements within the hygroscopic and the overhygroscopic moisture content range is conducted and evaluated. Within the frame of validation, the developments on the experimental as well as on the modelling fields are combined. The IPM experiments are recalculated on the basis of the measured initial and boundary conditions applying the adjusted and calibrated material functions. The comparison of measured and calculated data reveals the power of the developed material modelling just as the consequences of the simplifications made on the transport theory level. The distinct influences of the hysteresis of moisture storage consisting of effects depending on the process history and effects depending on the process dynamics, are proven. By the presented study, the material modelling has been decisively further developed, the set of basic measurement methods has been extended by a substantial experiment and the instantaneous profile measurement technique has been made applicable to Building Physics. Moreover, the influences of the process history and the process dynamics on the moisture transport and the resulting moisture profiles could be shown and proven. By that, not only a material model is now available which perfectly applies to the requirements of flexibility, applicability and extendability. The obtained data provides also a powerful basis for further research and development. / Die Genauigkeit hygrothermischer Bauteilsimulation hängt maßgeblich von den verwendeten Materialfunktionen ab. Sie werden durch die Materialmodellierung bestimmt, welche die Verbindung zwischen den aus Basisexperimenten gewonnenen Speicher- und Transportparametern sowie den innerhalb der Bilanz- und Flussgleichungen definierten Speicher- und Transportkoeffizienten herstellt. Ziel der vorliegenden Arbeit ist zum einen die Entwicklung eines flexiblen, breit anwendbaren und gleichzeitig nicht auf den gegenwärtigen Stand der Transporttheorie beschränkten Materialmodells. Dessen Grenzen und Möglichkeiten sollen zum anderen auf der Grundlage spezieller instationärer Feuchteprofilmessungen anhand von vier Baustoffen untersucht und aufgezeigt werden. Ausgangspunkt der Arbeit ist eine ausführliche Beleuchtung sowohl der vorhandenen Modellansätze als auch der zur Verfügung stehenden experimentellen Methoden zur Bestimmung hygrothermischer Basisparameter. Auf dieser Grundlage wird die Materialmodellierung in den Kontext der aus der Thermodynamik abgeleiteten Wärmeund Feuchtetransporttheorie eingeordnet. Die damit verbundenen Grenzen und Einschränkungen werden hervorgehoben und Entwicklungsmöglichkeiten sowie weiterer Entwicklungsbedarf aufgezeigt. Dieser umfasst drei Bereiche: die Experimente zur Bestimmung von Basisparametern, die Materialmodellierung, sowie Experimente zur Modellvalidierung. Die Reihe der Basisexperimente wird um den Trocknungsversuch unter definierten Bedingungen erweitert. Die verschiedenen Einflüsse auf die Trocknung und deren Anwendung in der Kalibrierung hygrothermischer Materialmodellierung werden herausgestellt und bewertet. Darauf aufbauend wird eine Apparatur entworfen, gebaut und angewendet. Schließlich werden Kriterien zur Standardisierung und Ableitung eines Einzahlenkennwertes evaluiert. Sinnvolle Erweiterungen werden aufgezeigt. Es wird ein eigenes Materialmodell auf der Grundlage eines Porenbündelansatzes hergeleitet, welches mit einem mechanistischen Ansatz gekoppelt wird, der den Feuchtetransport in seriell und parallel strukturierte Bereiche untergliedert. Die abgeleitete Flüssigwasserleitfähigkeit wird anhand von Leitfähigkeitsmessdaten im nahe gesättigten sowie im hygroskopischen Feuchtebereich justiert. Zwei interne Modellparameter werden anschließend unter Berücksichtigung der Hysterese der Feuchtespeicherung anhand des Aufsaug- und des Trocknungsversuches kalibriert. Das Materialmodell ist zur Erleichterung der Anwendung in ein Computerprogramm zur Anpassung an die Labordaten implementiert worden. Das Programm wird auf die vier Baustoffe Ziegel, Kalksandstein, Porenbeton und Calciumsilikat angewendet. Die entsprechend angepassten Materialfunktionen werden gezeigt und diskutiert. Im Rahmen der Kalibrierung wird eine hervorragende Übereinstimmung zwischen gemessenem und berechnetem Materialverhalten erreicht. Zur Modellvalidierung wird die Augenblicksprofilmethode (IPM) für die bauphysikalische Anwendung erweitert. Spezielle Apparaturen werden entwickelt und Versuchsabläufe entworfen. Modelle zur Ableitung des Wassergehaltes aus mit Hilfe der Time Domain Reflectometry (TDR) gewonnenen Dielektrizitätsmessdaten werden evaluiert und implementiert. Schließlich wird ein umfangreiches Programm an Feuchteprofilmessungen im hygroskopischen und überhygroskopischen Feuchtebereich umgesetzt und ausgewertet. Im Rahmen der Validierung werden die Entwicklungen auf experimenteller sowie auf Modellierungsebene zusammengeführt. Die IPM Experimente werden anhand der gemessenen Anfangs- und Randbedingungen und auf der Grundlage der angepassten und kalibrierten Materialfunktionen nachgerechnet. Der Vergleich zwischen Messung und Rechnung offenbart die Stärke der entwickelten Materialmodellierung ebenso, wie den Einfluss der auf Ebene der Transporttheorie getroffenen Vereinfachungen. Ein deutlicher Einfluss der sich aus der Prozessgeschichte sowie der Prozessdynamik zusammensetzenden Hysterese der Feuchtespeicherung kann nachgewiesen werden. Mit der vorliegenden Arbeit ist somit nicht nur die Materialmodellierung entscheidend weiterentwickelt, die Reihe der einfachen Basisexperimente um einen wesentlichen Versuch erweitert und die Augenblicksprofilmethode für bauphysikalische Belange anwendbar gemacht worden, es wurden auch die Einflüsse der Prozessgeschichte, und erstmals auch der Prozessdynamik, auf den Feuchtetransport sowie die sich einstellenden Feuchteprofile deutlich aufgezeigt und nachgewiesen. Es ist demnach nicht nur ein Materialmodell, welches den gestellten Anforderungen an Flexibilität, breite Anwendbarkeit und Erweiterbarkeit genügt, entwickelt worden, es wird mit den gewonnenen Messdaten auch die Grundlage weiterer Forschung zur Verfügung gestellt.

The achievable accuracy of hygrothermal building component simulation is significantly dependent on the applied material functions. These functions are determined by the material modelling marking the connection between the basic storage and transport parameters which are obtained from basic measurements, and the storage and transport coefficients which are defined within the balance and flow equations. It is the aim of the present study to develop a flexible and widely applicable material model which is not restricted to the current level of the transport theory. Furthermore, limits and options of this model are to be validated by means of four building materials on the basis of special transient moisture profile measurements. The study’s starting point is a comprehensive investigation of both, the different existing modelling approaches and the available experimental methods to determine basic hygrothermal material parameters. On this basis, the material modelling is set into the context of the heat and moisture transport theory derived from thermodynamics. The involved limits and restrictions are highlighted and options as well as requirements for further developments are pointed out. The developments this study focuses on comprise three fields: experiments for basic property determination, material modelling, and experiments for material model validation. The set of basic material investigation methods has been extended by the drying experiment under defined conditions. The different influences on the drying as well as its application to hygrothermal material model calibration are pointed out and appraised. On this basis, a drying apparatus is designed, built and applied. Ultimately, standardisation criteria and the derivation of a single-value drying coefficient are evaluated. Appropriate extensions are indicated. Based on the bundle of tubes approach, an own material model is developed. It is coupled with a mechanistical approach accounting for serial and parallel structured moisture transport phenomena. The derived liquid water conductivity is adjusted by the help of measured conductivity data close to saturation as well as within the hygroscopic moisture range. Subsequently, two internal modelling parameters are calibrated which is done by numerical simulation of the water uptake and the drying experiment under consideration of the hysteresis of moisture storage. Facilitating its application to the obtained laboratory data, the material model has been implemented into a computer program. It is applied to the four building materials brick, lime-sand brick, aerated concrete and calcium silicate. The adjusted material functions are shown and discussed. In all four cases, the calibration provides an excellent agreement between measured and calculated material behaviour. As experimental basis of the material model validation, the instantaneous profile measurement technique (IPM) has been extended to be applied in Building Physics. Special equipment is developed and measurement procedures are designed. Different models to derive the water content from dielectric data obtained by Time Domain Reflectometry (TDR) measurements are evaluated and implemented. Ultimately, an extensive program of transient moisture profile measurements within the hygroscopic and the overhygroscopic moisture content range is conducted and evaluated. Within the frame of validation, the developments on the experimental as well as on the modelling fields are combined. The IPM experiments are recalculated on the basis of the measured initial and boundary conditions applying the adjusted and calibrated material functions. The comparison of measured and calculated data reveals the power of the developed material modelling just as the consequences of the simplifications made on the transport theory level. The distinct influences of the hysteresis of moisture storage consisting of effects depending on the process history and effects depending on the process dynamics, are proven. By the presented study, the material modelling has been decisively further developed, the set of basic measurement methods has been extended by a substantial experiment and the instantaneous profile measurement technique has been made applicable to Building Physics. Moreover, the influences of the process history and the process dynamics on the moisture transport and the resulting moisture profiles could be shown and proven. By that, not only a material model is now available which perfectly applies to the requirements of flexibility, applicability and extendability. The obtained data provides also a powerful basis for further research and development. / Die Genauigkeit hygrothermischer Bauteilsimulation hängt maßgeblich von den verwendeten Materialfunktionen ab. Sie werden durch die Materialmodellierung bestimmt, welche die Verbindung zwischen den aus Basisexperimenten gewonnenen Speicher- und Transportparametern sowie den innerhalb der Bilanz- und Flussgleichungen definierten Speicher- und Transportkoeffizienten herstellt. Ziel der vorliegenden Arbeit ist zum einen die Entwicklung eines flexiblen, breit anwendbaren und gleichzeitig nicht auf den gegenwärtigen Stand der Transporttheorie beschränkten Materialmodells. Dessen Grenzen und Möglichkeiten sollen zum anderen auf der Grundlage spezieller instationärer Feuchteprofilmessungen anhand von vier Baustoffen untersucht und aufgezeigt werden. Ausgangspunkt der Arbeit ist eine ausführliche Beleuchtung sowohl der vorhandenen Modellansätze als auch der zur Verfügung stehenden experimentellen Methoden zur Bestimmung hygrothermischer Basisparameter. Auf dieser Grundlage wird die Materialmodellierung in den Kontext der aus der Thermodynamik abgeleiteten Wärmeund Feuchtetransporttheorie eingeordnet. Die damit verbundenen Grenzen und Einschränkungen werden hervorgehoben und Entwicklungsmöglichkeiten sowie weiterer Entwicklungsbedarf aufgezeigt. Dieser umfasst drei Bereiche: die Experimente zur Bestimmung von Basisparametern, die Materialmodellierung, sowie Experimente zur Modellvalidierung. Die Reihe der Basisexperimente wird um den Trocknungsversuch unter definierten Bedingungen erweitert. Die verschiedenen Einflüsse auf die Trocknung und deren Anwendung in der Kalibrierung hygrothermischer Materialmodellierung werden herausgestellt und bewertet. Darauf aufbauend wird eine Apparatur entworfen, gebaut und angewendet. Schließlich werden Kriterien zur Standardisierung und Ableitung eines Einzahlenkennwertes evaluiert. Sinnvolle Erweiterungen werden aufgezeigt. Es wird ein eigenes Materialmodell auf der Grundlage eines Porenbündelansatzes hergeleitet, welches mit einem mechanistischen Ansatz gekoppelt wird, der den Feuchtetransport in seriell und parallel strukturierte Bereiche untergliedert. Die abgeleitete Flüssigwasserleitfähigkeit wird anhand von Leitfähigkeitsmessdaten im nahe gesättigten sowie im hygroskopischen Feuchtebereich justiert. Zwei interne Modellparameter werden anschließend unter Berücksichtigung der Hysterese der Feuchtespeicherung anhand des Aufsaug- und des Trocknungsversuches kalibriert. Das Materialmodell ist zur Erleichterung der Anwendung in ein Computerprogramm zur Anpassung an die Labordaten implementiert worden. Das Programm wird auf die vier Baustoffe Ziegel, Kalksandstein, Porenbeton und Calciumsilikat angewendet. Die entsprechend angepassten Materialfunktionen werden gezeigt und diskutiert. Im Rahmen der Kalibrierung wird eine hervorragende Übereinstimmung zwischen gemessenem und berechnetem Materialverhalten erreicht. Zur Modellvalidierung wird die Augenblicksprofilmethode (IPM) für die bauphysikalische Anwendung erweitert. Spezielle Apparaturen werden entwickelt und Versuchsabläufe entworfen. Modelle zur Ableitung des Wassergehaltes aus mit Hilfe der Time Domain Reflectometry (TDR) gewonnenen Dielektrizitätsmessdaten werden evaluiert und implementiert. Schließlich wird ein umfangreiches Programm an Feuchteprofilmessungen im hygroskopischen und überhygroskopischen Feuchtebereich umgesetzt und ausgewertet. Im Rahmen der Validierung werden die Entwicklungen auf experimenteller sowie auf Modellierungsebene zusammengeführt. Die IPM Experimente werden anhand der gemessenen Anfangs- und Randbedingungen und auf der Grundlage der angepassten und kalibrierten Materialfunktionen nachgerechnet. Der Vergleich zwischen Messung und Rechnung offenbart die Stärke der entwickelten Materialmodellierung ebenso, wie den Einfluss der auf Ebene der Transporttheorie getroffenen Vereinfachungen. Ein deutlicher Einfluss der sich aus der Prozessgeschichte sowie der Prozessdynamik zusammensetzenden Hysterese der Feuchtespeicherung kann nachgewiesen werden. Mit der vorliegenden Arbeit ist somit nicht nur die Materialmodellierung entscheidend weiterentwickelt, die Reihe der einfachen Basisexperimente um einen wesentlichen Versuch erweitert und die Augenblicksprofilmethode für bauphysikalische Belange anwendbar gemacht worden, es wurden auch die Einflüsse der Prozessgeschichte, und erstmals auch der Prozessdynamik, auf den Feuchtetransport sowie die sich einstellenden Feuchteprofile deutlich aufgezeigt und nachgewiesen. Es ist demnach nicht nur ein Materialmodell, welches den gestellten Anforderungen an Flexibilität, breite Anwendbarkeit und Erweiterbarkeit genügt, entwickelt worden, es wird mit den gewonnenen Messdaten auch die Grundlage weiterer Forschung zur Verfügung gestellt.

This thesis details the application of a medium frequency (MF) Doppler radar to observations of meteoroids entering the Earth's atmosphere. MF radars make possible a greater height coverage of the meteor region (70 to 160 km) than conventional meteor radars. However this type of radar has generally been under-utilised for meteor observations, primarily due to the less than ideal radio environment associated with MF systems. This situation demanded selection of the most appropriate radar meteor techniques and in this respect a variety of techniques are evaluated for application at this frequency. The 2 MHz radar system used in this study is located at the Buckland Park research facility (35.6 deg. S, 138.5 deg. E), near Adelaide, South Australia and is operated by the Department of Physics of the University of Adelaide. This radar has the largest antenna of any MF radar with 89 crossed dipoles distributed over an area of about 1 km in diameter. Beam forming is achieved by varying the phase to groups of elements of the array. The array was constructed in the 1960's, and while having several upgrades, a preliminary examination of the array and associated systems indicated that a significant amount of maintenance work would be required to enable the system to be used for meteor observations. It was also apparent that the software used with the radar hardware for atmospheric studies was not suitable for processing meteor data. Thus a major refurbishment of the radar hardware, as well as the development of appropriate software, was initiated. The complete radar system was divided into its constituent components of antenna array, transmitter, receiver and computer systems. The transmitter and receiver systems were examined and various improvements made including increasing total output power and enhancing beam steering capability. Time domain reflectometry (TDR) techniques were extensively used on the antenna array, as many feed cables showed the presence of moisture. New hardware in the form of a portable power combining system was designed, constructed and tested to further increase radar experimental capabilities. Techniques were developed that verified system performance was to specification. Extensive night time observations of sporadic and shower meteor events were made over a two and a half year period. A particular study was made of the Orionids shower as well as other meteor activity on the night of 22 October 2000. Using the upgraded beam swinging features of the array, a narrow radar beam was used to track the shower radiant in an orthogonal sense so as to maximise the number of shower meteors detected. From each echo, various intrinsic meteoroid parameters were determined, including meteor reflection point angle-of-arrival using a five-element interferometer, echo duration and height; meteoroid speeds were determined using the Fresnel phase time technique. Meteor echoes belonging to the Orionids radiant were selected using a coordinate transform technique. The speed was then used as an additional discriminant to confirm the Orionid shower members. A second radiant, observed at a slightly higher declination is classified as also part of the Orionid stream. The sporadic meteor component in the data set was examined and found to exhibit speeds much higher than expected for sporadic meteors at the time of the observations. However, these results are consistent with a selection bias based on meteoroid speed, that is inherent in radar observations. The Orionid observations indicate that the refurbishment of the radar system and the introduction of new software for meteor analysis has been successfully achieved and that radar meteor studies can now be carried out routinely with the Buckland Park 2 MHz radar. Moreover it has been shown for the first time that meteoroid speeds can be determined with a MF radar operating on a PRF as low as 60 Hz. / Thesis (Ph.D.)--School of Chemistry and Physics, 2003.

Frequency response analysis (FRA) is a frequency-domain method which is used to detect mechanical faults in transformers. The frequency response of a transformer is determined by its geometry and material properties, and it can be considered as the transformer’s fingerprint. If there are any mechanical changes in the transformer, for example if the windings are moved or distorted, its fingerprint will also be changed so, theoretically, mechanical changes in the transformer can be detected with FRA. A problem with FRA is the fact that there is no general agreement about how to interpret the measurement results for detection of winding damages. For instance, the interpretation of measurement results has still not been standardized.The overall goal of this thesis is to try to enhance the understanding of the information contained in FRA measurements. This has been done in two ways: (1) by examining the FRA method for (much) higher frequencies than what is usual, and (2) by developing a new method in which FRA is combined with the ideas of Time Domain Reflectometry (TDR). As tools for carrying out the above mentioned steps, models for the magnetic core and the winding have been developed and verified by comparison to measurements.The usual upper frequency limit for FRA is around 2 MHz, which in this thesis has been extended by an order of magnitude in order to detect and interpret new phenomena that emerge at high frequencies and to investigate the potential of this high-frequency region for detection of winding deteriorations.Further, in the above-mentioned new method developed in this thesis, FRA and TDR are combined as a step towards an easier and more intuitive detection and localization of faults in transformer windings, where frequency response measurements are visualized in the time domain in order to facilitate their interpretation. / QC 20111122

This thesis details the application of a medium frequency (MF) Doppler radar to observations of meteoroids entering the Earth's atmosphere. MF radars make possible a greater height coverage of the meteor region (70 to 160 km) than conventional meteor radars. However this type of radar has generally been under-utilised for meteor observations, primarily due to the less than ideal radio environment associated with MF systems. This situation demanded selection of the most appropriate radar meteor techniques and in this respect a variety of techniques are evaluated for application at this frequency. The 2 MHz radar system used in this study is located at the Buckland Park research facility (35.6 deg. S, 138.5 deg. E), near Adelaide, South Australia and is operated by the Department of Physics of the University of Adelaide. This radar has the largest antenna of any MF radar with 89 crossed dipoles distributed over an area of about 1 km in diameter. Beam forming is achieved by varying the phase to groups of elements of the array. The array was constructed in the 1960's, and while having several upgrades, a preliminary examination of the array and associated systems indicated that a significant amount of maintenance work would be required to enable the system to be used for meteor observations. It was also apparent that the software used with the radar hardware for atmospheric studies was not suitable for processing meteor data. Thus a major refurbishment of the radar hardware, as well as the development of appropriate software, was initiated. The complete radar system was divided into its constituent components of antenna array, transmitter, receiver and computer systems. The transmitter and receiver systems were examined and various improvements made including increasing total output power and enhancing beam steering capability. Time domain reflectometry (TDR) techniques were extensively used on the antenna array, as many feed cables showed the presence of moisture. New hardware in the form of a portable power combining system was designed, constructed and tested to further increase radar experimental capabilities. Techniques were developed that verified system performance was to specification. Extensive night time observations of sporadic and shower meteor events were made over a two and a half year period. A particular study was made of the Orionids shower as well as other meteor activity on the night of 22 October 2000. Using the upgraded beam swinging features of the array, a narrow radar beam was used to track the shower radiant in an orthogonal sense so as to maximise the number of shower meteors detected. From each echo, various intrinsic meteoroid parameters were determined, including meteor reflection point angle-of-arrival using a five-element interferometer, echo duration and height; meteoroid speeds were determined using the Fresnel phase time technique. Meteor echoes belonging to the Orionids radiant were selected using a coordinate transform technique. The speed was then used as an additional discriminant to confirm the Orionid shower members. A second radiant, observed at a slightly higher declination is classified as also part of the Orionid stream. The sporadic meteor component in the data set was examined and found to exhibit speeds much higher than expected for sporadic meteors at the time of the observations. However, these results are consistent with a selection bias based on meteoroid speed, that is inherent in radar observations. The Orionid observations indicate that the refurbishment of the radar system and the introduction of new software for meteor analysis has been successfully achieved and that radar meteor studies can now be carried out routinely with the Buckland Park 2 MHz radar. Moreover it has been shown for the first time that meteoroid speeds can be determined with a MF radar operating on a PRF as low as 60 Hz. / Thesis (Ph.D.)--School of Chemistry and Physics, 2003.

This thesis details the application of a medium frequency (MF) Doppler radar to observations of meteoroids entering the Earth's atmosphere. MF radars make possible a greater height coverage of the meteor region (70 to 160 km) than conventional meteor radars. However this type of radar has generally been under-utilised for meteor observations, primarily due to the less than ideal radio environment associated with MF systems. This situation demanded selection of the most appropriate radar meteor techniques and in this respect a variety of techniques are evaluated for application at this frequency. The 2 MHz radar system used in this study is located at the Buckland Park research facility (35.6 deg. S, 138.5 deg. E), near Adelaide, South Australia and is operated by the Department of Physics of the University of Adelaide. This radar has the largest antenna of any MF radar with 89 crossed dipoles distributed over an area of about 1 km in diameter. Beam forming is achieved by varying the phase to groups of elements of the array. The array was constructed in the 1960's, and while having several upgrades, a preliminary examination of the array and associated systems indicated that a significant amount of maintenance work would be required to enable the system to be used for meteor observations. It was also apparent that the software used with the radar hardware for atmospheric studies was not suitable for processing meteor data. Thus a major refurbishment of the radar hardware, as well as the development of appropriate software, was initiated. The complete radar system was divided into its constituent components of antenna array, transmitter, receiver and computer systems. The transmitter and receiver systems were examined and various improvements made including increasing total output power and enhancing beam steering capability. Time domain reflectometry (TDR) techniques were extensively used on the antenna array, as many feed cables showed the presence of moisture. New hardware in the form of a portable power combining system was designed, constructed and tested to further increase radar experimental capabilities. Techniques were developed that verified system performance was to specification. Extensive night time observations of sporadic and shower meteor events were made over a two and a half year period. A particular study was made of the Orionids shower as well as other meteor activity on the night of 22 October 2000. Using the upgraded beam swinging features of the array, a narrow radar beam was used to track the shower radiant in an orthogonal sense so as to maximise the number of shower meteors detected. From each echo, various intrinsic meteoroid parameters were determined, including meteor reflection point angle-of-arrival using a five-element interferometer, echo duration and height; meteoroid speeds were determined using the Fresnel phase time technique. Meteor echoes belonging to the Orionids radiant were selected using a coordinate transform technique. The speed was then used as an additional discriminant to confirm the Orionid shower members. A second radiant, observed at a slightly higher declination is classified as also part of the Orionid stream. The sporadic meteor component in the data set was examined and found to exhibit speeds much higher than expected for sporadic meteors at the time of the observations. However, these results are consistent with a selection bias based on meteoroid speed, that is inherent in radar observations. The Orionid observations indicate that the refurbishment of the radar system and the introduction of new software for meteor analysis has been successfully achieved and that radar meteor studies can now be carried out routinely with the Buckland Park 2 MHz radar. Moreover it has been shown for the first time that meteoroid speeds can be determined with a MF radar operating on a PRF as low as 60 Hz. / Thesis (Ph.D.)--School of Chemistry and Physics, 2003.

Made available in DSpace on 2016-06-02T18:55:21Z (GMT). No. of bitstreams: 1 3737.pdf: 2114096 bytes, checksum: 58f7480198ad07cce74706f2adf51cad (MD5) Previous issue date: 2011-07-15 / Financiadora de Estudos e Projetos / Among various systems, the drip irrigation has been increasingly used, mainly because of its greater efficiency in water use. This work aimed to study the dynamics of soil solution, characterizing the distribution and storage of nutrients in the soil solution, and their absorption by pepper through the management of drip fertigation with two flows rates. The experiment was conducted in a greenhouse located in the Department of Agricultural Science, Unitau. The soil of study is an Oxisol Yellow, medium texture. The crop cycle lasted 120 days. From the readings of TDR probes were possible to estimate water content and soil solution concentration. Thus, the distribution of soil solution was monitored and counted in layers of 0,1m to 0,6 m. The evaluation of root system showed that the treatment of 4 L h-1 had an area of 69,31 cm2, while the treatment of 2 L h-1 had an area of 45,21 cm2. The productivity was 0,19 kg m-2 and 0,27 kg m-2 for 2 Lh-1 and 4 L h-1, respectively, what reinforces the results of nutrients distribution and root system development. It was found that for treatment with the flow rate of 2 L h-1 there was a trend of nutrient loss by percolation, increasing possible contamination of groundwater. The dripper with a flow rate of 4 L h-1 was more efficient at distributing and storing water and nutrients in a soil profile, which improved crop yield. / Dentre os vários sistemas, a irrigação por gotejamento tem sido crescentemente utilizada, principalmente pela sua maior eficiência no uso da água. O objetivo deste trabalho foi estudar a dinâmica da solução do solo caracterizando a distribuição, armazenamento e absorção de nutrientes pela planta de pimentão através do manejo da fertirrigação por gotejamento, em função de duas vazões. O ensaio foi realizado em uma casa de vegetação localizado no Departamento de Ciências Agrárias da Unitau. O solo do local do estudo é um Latossolo Vermelho Amarelo de textura média. O ciclo da cultura durou 120 dias. A partir das leituras das sondas de TDR foi possível estimar a umidade e a concentração da solução do solo. Assim, a distribuição da solução no solo foi monitorada e contabilizada em camadas de 0,1 m até 0,6 m. A avaliação do sistema radicular mostrou que o tratamento de 4L h-1 apresentou uma área de 69,31 cm2 enquanto o tratamento de 2 L h-1 apresentou uma área de 45,21 cm2. A produtividade observada foi de 0,19 kg m-2 e 0,27 kg m-2 para 2 e 4 L h-1, reforçando os resultados vistos na distribuição de nutrientes, desenvolvimento do sistema radicular. Verificou-se que para o tratamento com vazão de 2 L h-1 houve uma tendência de perda de nutrientes por percolação, potencializando possíveis contaminações do lençol freát ico. O gotejador com vazão de 4 L h-1 mostrou-se mais eficiente na distribuição e armazenamento de água e nutrientes em um perfil do solo, o que favoreceu o rendimento da cultura.

Orientadores: Edson Eiji Matsura, Zigomar Menezes de Souza / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-17T15:08:46Z (GMT). No. of bitstreams: 1 Bizari_DouglasRoberto_D.pdf: 8370822 bytes, checksum: e5f2514514958e8b994537236acbeec8 (MD5) Previous issue date: 2011 / Resumo: A potencialidade do sistema plantio direto (SPD) na conservação da água e do solo, aliado à necessidade de pesquisas com culturas irrigadas nesse sistema, principalmente no Estado de São Paulo, determina uma demanda de informações nessa área, visando minimizar a degradação dos recursos hídricos, normalmente utilizado de maneira inadequada na busca por elevadas produtividades. Diante da importância da necessidade da água para irrigação, torna-se imprescindível a conscientização do produtor rural com relação ao seu manejo racional, que pode ser alcançado tanto pela implantação de técnicas conservacionistas quanto pela utilização de equipamentos de monitoramento da umidade do solo mais práticos e eficientes. Apesar da sua importância para o sucesso do SPD irrigado, há uma carência, no Estado de São Paulo, de estudos voltados para a quantidade adequada de cobertura morta na superfície do solo, que possa proporcionar disponibilidade de água necessária para as plantas, durante o seu ciclo de desenvolvimento, levando-se em conta a sua decomposição, que pode ser mais ou menos rápida, dependendo das condições climáticas da região. Baseado nisso, estudou-se a influência de diferentes quantidades de cobertura morta de milho na conservação da umidade e produtividade da cultura do feijoeiro, avaliando-se também a técnica da TDR (Reflectometria no domínio do tempo) no monitoramento da umidade do solo, na redistribuição da água no seu interior e no manejo da irrigação. Para isso, foi semeada a cultura do feijão, variedade Pérola, na época de inverno nos anos de 2007, 2008 e 2009. Na primeira safra, caracterizou-se o sistema radicular da cultura ao longo de todo seu ciclo de desenvolvimento, buscando-se uma relação com os parâmetros da parte aérea, e também, como uma forma de aprimorar o cálculo da lâmina de água aplicada nas culturas irrigadas, contribuindo para um manejo mais racional da irrigação e um menor desperdício de água aplicada no SPD. Na segunda safra, verificou-se a influência de diferentes quantidades de cobertura morta de milho na temperatura e umidade do solo na cultura do feijoeiro irrigado em SPD e na última safra avaliou-se a decomposição dessas diferentes quantidades de cobertura morta ao longo de todo o ciclo da cultura e também, desenvolveu-se um equipamento portátil para otimizar as leituras de umidade no campo por sondas de TDR, como proposta de uma ferramenta para ser utilizada no manejo da irrigação e ensaios de redistribuição de água no interior do solo. Foi possível verificar que a profundidade efetiva de raízes do feijoeiro variou ao longo do ciclo da cultura, apresentando boa correlação com a altura de plantas, índice de área foliar e massa seca da parte aérea. Que a maior quantidade de cobertura morta de milho proporcionou as menores taxa de decomposição, os maiores valores de umidade do solo, os menores valores de temperatura do solo e a maior produtividade de grãos e de seus componentes de produtividade. Finalmente a técnica da TDR juntamente com o equipamento portátil para uma única sonda de TDR foi viável no monitoramento da umidade do solo, podendo também ser empregada no manejo da irrigação e ensaios de redistribuição de água no interior do solo. / Abstract: Due to the potential of the no-tillage system (SPD) in the water and soil conservation combined with the need for research with irrigated crops in this system, mainly in the State of São Paulo, has been increasing the demand for information to minimize the degradation of hydrical resources, inappropriately used in the search for higher productivities. However, due to the importance of the need of water for irrigation, it becomes essential to farmers awareness to water rational management, by implementation of conservation techniques and also practical and efficient equipments for monitoring soil moisture. Despite its importance in the success of the SPD, there is a lack of studies, about permanence and adequate amount of mulch on the soil surface, which may provide water availability needed for plants for a longer period of time, considering mulch decomposition. So, studies were conducted to evaluate the influence of different amounts of maize mulch in the moisture conservation and dry bean productivity and also, to evaluate the TDR technique to monitor soil moisture and irrigation management and soil water redistribution. For that, was sown dry bean, Pérola variety, in the winter period, during years 2007, 2008 and 2009. In the first year, was characterized the dry bean root sytem, throughout its development cycle to find a relation with the aerial part, and also, as way to improve the irrigation water applied calculation to crops irrigated, contributing to rational irrigation management. On the second year, the objective was to verify the influence of different amounts of maize mulch in the soil moisture conservation, temperature and crop productivity, and in the last year was development a portable equipment to optimize the moisture readings in the field with TDR probes, such as proposed tool to be used for irrigation management and soil water redistribution tests. It was possible to verify that the dry bean effective root depth varied during the crop cycle, showing good correlation with plant height, leaf area index and dry mass of aerial part. The largest quantify of maize mulch provided largest values of soil moisture, less values of soil temperature and largest grain yield and its productivity components. The TDR technique with the portable equipment was feasible to monitor soil moisture and can be used for irrigation management and soil water redistribution tests. / Doutorado / Agua e Solo / Doutor em Engenharia Agrícola

Orientador: Edson Eiji Matsura / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-09T04:32:01Z (GMT). No. of bitstreams: 1 Roque_MarcioWilliam_D.pdf: 4566160 bytes, checksum: e232b1dbf290d1893cd9821cda298632 (MD5) Previous issue date: 2007 / Resumo: Diante da importância da necessidade de água para irrigação, torna-se imprescindível a conscientização do produtor rural com relação ao seu manejo racional, pois a irrigação tem sido apontada, ao longo das últimas décadas, como a grande consumidora de água. Diversos trabalhos têm mostrado que a prática do manejo racional da irrigação associada ao sistema plantio direto leva o agricultor a produzir igual ou até mais, em relação ao plantio convencional, com um menor consumo de água, evitando-se assim, o desperdício desse recurso, além de contribuir para o desenvolvimento de uma agricultura sustentável. Entretanto, dependendo do tempo, das condições de implantação e manejo do plantio direto, em muitas lavouras verificou-se um aumento do estado de compactação, com aumento de densidade do solo e da resistência mecânica à penetração, causando perda na produção. Diante do exposto, o objetivo deste trabalho foi avaliar a dependência espacial dos atributos físico-hídricos do solo e da produção, verificando-se as inter-relações destes com a produção de grãos do feijoeiro irrigado sob sistema plantio direto e convencional, e também verificar o uso da técnica Reflectometria no Domínio do Tempo (TDR) no monitoramento da umidade do solo nos mesmos sistemas. Para isso foi semeado o feijão como cultura de inverno durante as safras de 2005 e 2006 em quatro parcelas experimentais conduzidas sob plantio direto e convencional, irrigado e não irrigado. Em cada parcela experimental de dimensões de 20 x 30m, foram definidas malhas de amostragem de 3 x 3m, totalizando 60 pontos amostrais por parcela. O solo das parcelas pertence à classe Latossolos Vermelhos Distroférricos típicos. Nos pontos amostrais foram inseridas sondas de TDR para o monitoramento da umidade do solo, e determinada a condutividade hidráulica saturada, a resistência do solo à penetração e retirada de amostras para a determinação da densidade do solo. Utilizando-se de um nível óptico foi determinada a cota em metros de cada ponto amostral nas parcelas estudadas. A análise da dependência espacial foi avaliada por meio da geoestatística, e os parâmetros dos semivariogramas utilizados para construir mapas de isolinhas utilizando-se do interpolador de krigagem pontual disponível no programa Surfer 8.0. Os principais resultados obtidos indicaram que a calibração da TDR proposta por Topp et al. (1980) como universal, não é adequada para o solo estudado. A técnica da TDR foi eficiente no monitoramento da umidade do solo ao longo do ciclo da cultura do feijoeiro e pode ser empregada no manejo da irrigação, desde que se faça a previa calibração do equipamento para o solo estudado. Os valores de resistência do solo à penetração (RP), para os dois sistemas de manejo do solo aumentaram de uma safra para outra, sendo que no plantio direto este aumento foi superior, ultrapassando os valores de RP do plantio convencional na safra de 2006. Entretanto os valores obtidos não interferiram na produtividade do feijoeiro nos dois sistemas de preparo do solo. Os valores da condutividade hidráulica saturada, para os dois sistemas de manejo do solo aumentaram de uma safra para outra, sendo que na safra de 2006, os valores de condutividade hidráulica saturada para o sistema plantio direto foram superiores ao convencional. Com relação à densidade do solo, na safra de 2005, o plantio convencional obteve menor valor médio, e, na safra 2006, os valores médios da densidade do solo foram os mesmos para os dois sistemas de manejo. Todos os atributos físico-hídricos e a produtividade de grãos apresentaram dependência espacial nos dois sistemas de manejo do solo para as duas safras agrícolas. Com relação às inter-relações entre os atributos estudados e a produção, todas as regressões lineares simples não mostraram correlação com a produção. A regressão linear simples entre os mapas dos atributos estudados e a produção, mostrou-se significativas, com baixos valores de coeficiente de determinação. O melhor resultado obtido foi com a relação densidade do solo e a produção no sistema plantio convencional na safra 2005, com coeficiente de determinação de 43,39 %, ou seja, dentro das variáveis estudadas foi a que melhor explicou a variação da produção. Na busca de um modelo que explicasse a variação da produção em função dos atributos físico-hídricos do solo e da cota do relevo, utilizou-se da regressão linear múltipla pelo método stepwise obtendo-se modelos significativos estatisticamente que explicaram a variação da produção com coeficientes de determinação entre 27,34 % e 71,70 % / Abstract: Since last decades irrigation practices are recognized as major water consumers, requiring specific agricultural producers education and awareness on water use and supply. Recent research reports indicate significant water economy, crop yielding as well as contribution to sustainable agricultural development, if direct seedling, when compared with conventional practices, is associated to adequate irrigation management. However, depending on weather conditions as well as on the direct seedling implementation conditions, many crop plantations showed increasing soil bulk density and compaction with increasing soil mechanical resistance to penetration, causing crop production reduction. Based on what it has been exposed before, the objective of this research is to evaluate crop yielding and soil physical-hydric attributes spatial dependence as related to irrigated bean grain production associated to no-tillage and to conventional tillage systems. The Time Domain Reflectometry (TDR) efficiency in the soil moisture monitoring in the same crop systems was also evaluated. Four experimental plots with dimensions of 20m x 30m were seeded with beans in the years and 2005 and 2006 and carried under irrigated and non irrigated conventional as well as no-tillage systems. Each plot was screened with 3m x 3m sampling grids, completing a total of 60 sampling points in each plot. Plot soil was classified as Typical Distroferric Red Latossol. TDR probes were introduced into the soil on each plot to monitor moisture content, also being measured saturated hydraulic conductivity, resistance to penetration and sampling for soil bulk density determination. Elevation of each sampling point was determined by means of an optical instrument and expressed in meters. Spatial dependence analysis was evaluated through geostatistic techniques and the semivariograms parameters were employed to generate isoline maps trough the punctual kriging interpolator of the Surfer 8.0 program. Obtained results indicated TDR calibration as proposed by Topp et al. (1980), considered of universal feature, is not adequate to the soil under study. TDR technique showed to be efficient in monitoring soil moisture content throughout bean plant cycle, being applicable in the irrigation process, since a previous equipment calibration in accordance with soil type under study. Soil resistance to penetration associated to both management systems showed increased value from one harvest to the next one, being greater for no-tillage system, surpassing the RP value associated to the conventional tillage for the year of 2006. However, obtained values do not interfere in the bean plant productivity for both employed growing system. Values saturated hydraulic conductivity had increased from one harvest to the next, observing that for the year of 2006 no-tillage system showed larger values than the conventional one. Conventional tillage showed lower soil bulk density average values for the year of 2005, however these values became the same for both methods in the year of 2006 harvest. All physical-hydric attributes as well as grain productivity presented spatial dependence for both soil cultivation techniques for both harvesting periods. All of simple linear regressions showed no correlation between attributes and bean production. However, simple linear regressions showed to be significant for attribute maps and production, presenting low determination coefficient values. The best observed result was identified to be the soil density related to production for the conventional crop management, showing the determination coefficient of 43,39 %, i.e., which is considered the best explaining production variation variable. In looking for a model explaining production variation as a function of soil physical-hydric attributes and relief elevation by means of multiple linear regression by the stepwise method, statistically significant models which explains production variation between 27,34 % to 71,70 % / Doutorado / Agua e Solo / Doutor em Engenharia Agrícola

O conhecimento da movimentação da água no solo é de grande importância para a agricultura, pois a água é um dos fatores que mais influenciam no rendimento das culturas. Das várias técnicas utilizadas para o monitoramento do conteúdo de água no solo, a reflectometria no domínio do tempo (TDR) vem sendo bastante difundida entre os pesquisadores por apresentar inúmeras vantagens, dentre as quais a mensuração em tempo real e a possibilidade de leituras automatizadas. Com o objetivo de avaliar a movimentação da água num perfil de um Latossolo vermelho-amarelo, conduziu-se um experimento obtendo-se os valores de umidade do solo e condutividade elétrica através das leituras de um equipamento de TDR com sondas instaladas em uma trincheira em diversas profundidades (0,10 m a 0,60 m) e com diferentes taxas de aplicação (2, 4 e 8 L.h-1) de solução em intervalos de 1 hora, via irrigação por gotejamento. A partir dos resultados obtidos, pôde concluir-se que diferentes vazões de aplicação determinam características particulares de formação do bulbo molhado e da movimentação da solução no solo. Para as condições de solo e de acordo com o volume e a frequência utilizada durante este experimento, recomenda-se a aplicação de pequenas quantidades de solução em intervalos mais frequentes para reduzir a perda por percolação de água e solutos. / The knowledge of the water distribution in soil has great importance to the agriculture because of the crop yield the cultures income has a direct influence by the water. There are many techniques used to monity soil moisture, and the time domain reflectometry (TDR), has a satisfactory application among the researches because the advantages, allow the real time measurements can be automatized and the automatized. With the objective to appraise the water distribution and electrical conductivity in a Red-yellow Latosol profile, the experiment was conducted measuring soil moisture through the TDR equipment reading with probes fixed in a trench in various depths (0,10 m to 0,60 m) and with different applications rates of solution (2,4 and 8 L.h-1) , with one hour interval by dripping irrigation. The results allowed us to that the different sewages applications determinate the particular characteristics of the wet bulb arrangement and the water soil distribution. For the soil conditions and according to the volume and frequency used during this experiment, it is recommended to apply of small quantities of a solution at more frequent intervals to reduce the loss by percolation of water and solute.