ITC/USA 2014 Conference Proceedings / The Fiftieth Annual International Telemetering Conference and Technical Exhibition / October 20-23, 2014 / Town and Country Resort & Convention Center, San Diego, CA / This paper addresses the future military munitions' system requirements for antennas in terms of the existing versus new fabrication technology. The antenna requirements of the future smart munitions will be GPS for precision guidance and TM for system performance testing. The environmental requirements remain the same; large temperature operating range with operation at high temperatures and high shock capable. As usual, the munitions are getting smaller, frequency bandwidth is getting larger, and the cost of the antennas must be minimized in production quantities. In particular this paper compares the existing antenna fabrication technology of Teflon based dielectric printed circuits versus multilayer alumina in the green state, a technology that has been perfected for fabricating microwave integrated circuits (MIC's). The trade-offs that will be addressed are temperature, shock, cost, tunability, loss, size, dielectric constant, and frequency bandwidth. There has been a significant effort to miniaturize the GPS and TM antenna using higher dielectric constant materials. The most popular direction of this effort has been to use ceramic impregnated Teflon. The ultimate temperature performance is the material with a dielectric constant around 2 since this material exhibits a very low coefficient of change with temperature. Materials are available with nominal dielectric constants of 6 and 10 to reduce the size of the antenna but the coefficient of change with temperature is very large and leaves these materials marginal for military temperature ranges. There have also been two other problems with Teflon based printed circuit boards, forming and bonding the boards in a 3D shape and homogeneity of the dielectric constant in the board and after bonding. These problems usually make tuning a requirement and drive the cost of antenna fabrication up. There has been a revolution in MIC's. The circuits are now being made with multiple layers of ceramic (alumina) with interlayer conductive connections and a nominal dielectric constant of 10. The layers are formed in the green state and fired at high temperature and the resulting alumina substrate has a very low coefficient of change with temperature and low loss. Since this procedure is now beyond development, the cost is low and the volume capability is high. Another significant point is that the part can be any shape since the substrate is done in the green state (formable) and then fired.

The increasing interest of modeling global carbon cycling during the past two decades has driven this research to map leaf area index (LAI) at multiple spatial resolutions by combining LAI field observations with various sensor images at local, regional, and global scale. This is due to its important role in process based models that are used to predict carbon sequestration of terrestrial ecosystems. Although a substantial research has been conducted, there are still many challenges in this area. One of the challenges is that various images with spatial resolutions varying from few meters to several hundred meters and even to 1 km have been used. However, a method that can be used to collect LAI field measurements and further conduct multiple spatial resolution mapping and accuracy assessment of LAI is not available. In this study, a pilot study in a complex landscape located in the Southern Illinois was carried out to map LAI by combining field observations and remotely sensed images. Multi-scale mapping and accuracy assessment of LAI using aerial photo, Landsat TM and MODIS images were explored by developing a multi-scale sampling design. The results showed that the sampling design could be used to collect LAI observations to create LAI products at various spatial resolutions and further conduct accuracy assessment. It was also found that the TM derived LAI maps at the original and aggregated spatial resolutions successfully characterized the heterogeneous landscape and captured the spatial variability of LAI and were more accurate than those from the aerial photo and MODIS. The aerial photo derived models led to not only over- and under-estimation, but also pixilated maps of LAI. The MODIS derived LAI maps had an acceptable accuracy at various spatial resolutions and are applicable to mapping LAI at regional and global scale. Thus, this study overcame some of the significant gaps in this field.

Made available in DSpace on 2014-06-11T19:30:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-02Bitstream added on 2014-06-13T19:00:21Z : No. of bitstreams: 1 salvador_jf_me_botfca.pdf: 547576 bytes, checksum: ad1bd6019cb2229abcb68c064372a6f5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O setor florestal brasileiro ocupa destaque no cenário mundial da cultura de florestas plantadas. A ampliação das áreas com florestas plantadas demandam desenvolvimento tecnológico e otimização de mão-de-obra. O uso da aviação está em franca expansão na atividade florestal. O presente trabalho teve o objetivo de definir qual a melhor combinação entre alturas de vôo e volumes de calda na aplicação aérea de herbicidas em área de implantação florestal por meio de análise de deposição das caldas. O experimento foi realizado em área de pastagem da Fazenda Morro Branco, situada no município de Porto Espiridião no Estado de Mato Grosso. O ensaio foi instalado com nove tratamentos que consistiram nas combinações de três volumes de calda (20, 30 e 50 L ha-1) e três alturas de vôo (10, 30 e 40 m). As aplicações foram realizadas utilizando-se uma Aeronave Air Tractor AT-802, equipada com barras contendo 54 bicos com pontas de jato plano ajustáveis. Os dados foram analisados inicialmente por meio de mapas para verificar a variabilidade espacial e tendência da distribuição pontual dos depósitos das caldas. Posteriormente foi realizada a análise comparativa dos tratamentos utilizando o método estatístico “Intervalo de Confiança para Diferenças entre as Médias” com grau de confiança de 95% (IC95%). Para a determinação dos depósitos de calda foi utilizado metodologia de cromatografia líquida de alta eficiência (HPLC) e para determinação de deriva foi utilizado balanço de massas. Em geral, houve tendência de aumento de depósitos de calda com a redução da altura de vôo, independente do volume aplicado. Os tratamentos com altura de vôo de 10 m apresentaram quantidades de depósitos superiores aos demais tratamentos, independente do volume de calda aplicado / The Brazilian forestry sector takes a highlight position on the global forest plantations. Forestry plantation areas are in expansion and require technological development and workmanship optimization. The use of aviation technology is growing in forest areas. The aim of the study was to define the best combination of height flight and spray volume rates in aerial herbicides application in forestry establishment area by deposition analysis. The experiment was conducted in a pasture area at Morro Branco Farm, located in Porto Espiridiao City, Mato Grosso State. The test was set up with nine treatments, consisted of three spray volumes rates (20, 30 and 50 L ha-1) and three height flights (10, 30 and 40 m). The applications were performed by Aircraft Air Tractor AT-802, equipped with boom containing 54 nozzles with adjustable flat fan tips. Data were analyzed initially by using maps to determine the spatial distribution and trend of timely deposits of mixtures. Afterwards, for comparison between treatments, the statistical method Confidence Intervals for Differences between Means was used, with confidence level of 95%. Spray deposits was determinate by High Performance Liquid Chromatography (HPLC) and for drift determination was used mass balance. In general, there was a tendency to increase spray deposits by reducing flying height, regardless of the volume applied. The treatments with 10 m flying height had higher deposits amounts, regardless of spray volume rate

Submitted by Fernanda Rodrigues de Lima (fernanda.rlima@ufpe.br) on 2018-07-20T22:25:02Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Regina Juliana Galdino da Silva.pdf: 3770049 bytes, checksum: f9c6cc1bf5b5de8eb4f8de0a058115a6 (MD5) / Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-07-23T18:03:58Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Regina Juliana Galdino da Silva.pdf: 3770049 bytes, checksum: f9c6cc1bf5b5de8eb4f8de0a058115a6 (MD5) / Made available in DSpace on 2018-07-23T18:03:58Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Regina Juliana Galdino da Silva.pdf: 3770049 bytes, checksum: f9c6cc1bf5b5de8eb4f8de0a058115a6 (MD5) Previous issue date: 2017-02-15 / CNPq / O monitoramento de dose pessoal, clínica ou ambiental é de extrema importância para a otimização de processos de exposição do meio à radiação ionizante e para avaliação de risco associado a estas práticas. Uma das técnicas dosimétricas utilizada neste sistema de monitoração se dá por meio da propriedade de luminescência de alguns materiais. Dentre os diversos materiais conhecidos, têm-se o fluoreto de cálcio dopado com túlio (CaF₂:Tm) que é bastante utilizado na dosimetria por termoluminescência. Entretanto, este material foi pouco estudado com relação à suas propriedades de luminescência opticamente estimulada (OSL). A dosimetria OSL, comparada à dosimetria termoluminescente, apresenta uma vantagem principal, que é a remoção do processo de aquecimento na leitura do dosímetro, eliminando problemas relacionados à reprodutibilidade do sistema de aquecimento e ao quenching térmico, que influencia na eficiência da luminescência. Por isso, o objetivo deste trabalho foi avaliar a resposta OSL do CaF₂:Tm sintético e, consequentemente, realizar uma avaliação preliminar das características desse material para dosimetria OSL. Para tanto, esse estudo foi dividido em três etapas: (i) a produção das amostras de CaF₂:Tm sintético pelo método de combustão; (ii) o estudo dos parâmetros de aquisição dos instrumentos de medição da resposta OSL; e (iii) a caracterização dos principais parâmetros dosimétricos. Os resultados deste trabalho mostraram que o CaF₂:Tm apresenta resposta OSL tanto para estimulação com LED azul quanto para infravermelho, apresentando maior eficiência para este último, o que é uma inovação dado que o único material conhecido que responde a estimulação infravermelha é o feldspato, amplamente utilizado em aplicações de datação. Além disso, a pesquisa mostrou que a luz branca apresenta comprimento de onda eficaz no zeramento óptico do sinal luminescente das amostras. As análises dos testes para utilização do CaF₂:Tm sintético como dosímetro mostraram que as amostras produzidas apresentaram alta reprodutibilidade (CV< 3%), com linearidade na resposta à dose entre 100 mGy e 2,5 Gy, e apresentando uma dose mínima mensurável de 0,1 mGy, atendendo aos requisitos de dose mínima para aplicações em dosimetria pessoal. Desta forma, o trabalho mostra que é possível a utilização do CaF₂:Tm sintético como dosímetro utilizando suas propriedades OSL. / Personal, clinical or environmental dose monitoring is of extreme importance for the optimization of the processes of exposing the environment to ionizing radiation and for assessing the risk associated with these practices. One of the dosimetric techniques used in this monitoring system is through the luminescence property of some materials. Among the various known materials are thulium doped calcium fluoride (CaF₂: Tm) which is widely used in thermoluminescence dosimetry. However, this material was little studied with respect to its optically stimulated luminescence (OSL) properties. The OSL dosimetry, compared to thermoluminescent dosimetry, has a main advantage, which is the removal of the heating process in the dosimeter reading, eliminating problems related to the reproducibility of the heating system and thermal quenching, which influences the efficiency of the luminescence. Therefore, the objective of this work was to evaluate the OSL response of CaF₂: synthetic Tm and, consequently, to perform a preliminary evaluation of the characteristics of this material for OSL dosimetry. For this, the study was divided into three stages: (i) the production of samples of CaF₂:Tm synthetic by the combustion method; (ii) the study of the acquisition parameters of the OSL response measurement instruments; and (iii) the characterization of the main dosimetric parameters. The results of this work showed that CaF₂: Tm presents an OSL response for both blue and infrared LED stimulation, presenting a higher efficiency for the latter, which is an innovation since the only known material that responds to infrared stimulation is feldspar, widely used in dating applications. In addition, the research showed that white light has an effective wavelength in the optical bleaching of the luminescent signal of the samples. Analyzes of the tests for use of CaF₂: synthetic Tm as a dosimeter showed that the samples produced had a high reproducibility (CV <3%), with linearity in dose response between 100 mGy and 2.5 Gy, and presenting a minimum measurable dose of 0.1 mGy, meeting the minimum dose requirements for personal dosimetry applications. Thus, the work shows that it is possible to use the CaF₂: synthetic Tm as a dosimeter using its OSL properties.

A telemetry facility may connect numerous telemetry receivers to a single tracking antenna depending on the number of TM channels involved in the test and on the required redundancy. The tracking data, i.e. AM normalized analog signals extracted by the receivers from the TM signal and the AGC analog signals, are sent to the Antenna Control Unit (ACU) for tracking error calculation. The number of cables between receivers and ACU becomes important in some telemetry facilities and the tracking signals being analog, the distance must be limited. This paper proposes a new tracking architecture that moves from analog to digital links between receivers and ACU with the following main benefits:  Keeping the capability to acquire tracking data (AM&AGC) from several telemetry receivers,  Having more flexibility for integration,  Improving interoperability,  Providing availability of simultaneous tracking errors for enhanced tracking algorithms, for C-band tracking improvement for example.

This project, elaborated in terms of Master’s studies in domain 2303T005 presents an analysis comparing conventional method of welding MAG and welding technology ESAB SAT^TM. ESAB SAT^TM is the new innovative method based on the principle of welding by the method MAG. The experimental part of the project is aimed to assessing the quality of welded joints, produced by ESAB SAT^TM, which part is performing selected destructive tests. Afterwards economic analysis by comparative method evaluates the measured and calculated parameters of welding.

Electricity-driven water splitting reaction achieved by electrochemical method to produce hydrogen and oxygen is utilized as an energy carrier in the form of highly pure hydrogen gas. However, the development of earth-abundant, durable, and highly effective electrocatlyst to overcome the high overpotentials of hydrogen, and oxygen evolution reaction (HER, OER) is extremely challenging. This dissertation presents firstly the catalytic properties of tungsten disulfide (WS2) as highly effective HER catalyst through direct growth of 2H-WS2 layered materials on a conductive substrate. Effect of various gaseous atmosphere and temperatures was studied and it was found that the amorphous structure of WS2 can be strongly affected under H2S environment which leads to the formation of bridging disulfide ligands S2 2- and apical S2- from WS3 phase, which is consequently contribute to the catalytic enhancement toward HER with extremely low overpotential (η10 = 184 mV). On the other hand, OER is the major bottleneck in water splitting reaction due to its poor kinetics originated from the complex four electrons transfer process. Chemical vapor deposition strategy is used here to enable stoichiometric tuning and phase engineering of CoP2 OER electrocatalyst followed by deposition of carbonaceous protection layer to overcome surface oxidation. Electrochemical studies indicate that C@CoP2/CC can achieve a remarkable activity (η10 = 234 mV), with minor decay from its initial current density after continuous operation of 80 hours. Lastly, electrolysis of alkaline water is the most common industrial method to produce H2; however, it is a formidable challenging to compete with Pt catalyst in base at industrial scale. For that, temperature-dependent phase evolution was studied in details and it is found that (Co(OH)2) precursor undergoes phase transition under a unique phosphidation system starting with partially phosphatized phase CoP-CoxOy, followed by phosphorus rich phase CoP2, and ultimately to pure CoP phase under elevated temperatures. Comprehensive analysis revealed that concerted composite CoP-CoxOy is the most active phase to produce H2 electrochemically from alkaline water which is contributed to the unique role of integrated phase and its ability to overcome the sluggish hydrogen kinetics in base.

Change detection is currently a topic of great interest to theoretic geographic researchers. The necessity to map, monitor, and model land cover change is also important to a variety of applied fields as varied as urban planning and military intelligence. This research compares five algorithms to map urban land cover change in the greater Las Vegas, Nevada metropolitan area. Landsat Thematic Mapper imagery acquired on May 1990 and May 2000 was used as the primary data. The change detection methods yielded simple maps of change vs. no change. These algorithms included image differencing, image ratioing, image regression, vegetation index differencing, and principal components analysis. Each of these techniques accurately identified areas of land cover with moderate levels of accuracy and produced overall change detection accuracy values between 60% and 76% depending on the method. The highest accuracy was obtained by the image ratioing method using the red spectral band (76%). As expected, the determination of change detection thresholds for each technique was critical to the accuracy produced by the algorithm. Moreover, the type of statistic used in optimizing that threshold was also a significant impacting the final accuracy. The approach of using a set of ground points to calibrate the change detection threshold proved to have significant merit.

Carried out in collaboration with the Occoquan Water Monitoring Lab, this thesis presents the results of research that sought to ascertain the spatial distribution of chlorophyll-a concentrations in the Lake Manassas Reservoir using a combination of Landsat TM satellite imagery and ground based field measurements. Images acquired on May 14, 1998 and March 8, 2000 were analyzed with chlorophyll-a measurements taken on 13, 1998 and March 7, 2000. A ratio of Landsat TM band 3: Landsat Band 4 was used in a regression with data collected at eight water quality monitoring stations run by the Occoquan Watershed Monitoring Lab. Correlation coefficients of 0.76 for the 1998 data and 0.73 for the 2000 data were achieved. Cross validation statistical analysis was used to check the accuracy of the two models. The standard error and error of the estimate were reasonable for the models from both years. In each instance, the ground data was retrieved approximately 24 hours before the Landsat Image acquisition and was a potential source of error. Other sources of error were the small sample size of chlorophyll-a concentration measurements, and the uncertainty involved in the location of the water quality sampling stations. / Master of Science

Aquatic vegetation plays an important role in the ecological interactions and processes within a water body. However, the presence of the invasive exotic aquatic plant species, waterhyacinth [Eichhornia crassipes (Mart.) Solms], negatively affects those interactions as well as interfering with water use for recreation and navigation. An implemented management plan for waterhyacinth control relies on the use of herbicides. Efficacy is commonly assessed using visual injury and control ratings as well as estimating biomass. The problem is that those approaches are labor intensive only assessing single points throughout the entire water body. Therefore, technology like remote sensing, which is the focus of this research, is recommended as an additional tool to assess implemented management plans. Studies were conducted in a mesocosm research facility to evaluate the relationship between simulated spectral bands 3, 4, 5, and 7 Landsat 5 TM and waterhyacinth treated with the herbicides imazapyr and glyphosate. Results indicate that injury is better detected and predicted with band 4 and that relationship is negative when either herbicide was used. However, prediction is better when plants have developed sufficient injury to influence the spectral response of band 4. In the second study, the biomass of waterhyacinth was estimated using the Normalized Difference Vegetation Index (NDVI) using simulated data from Landsat 5 TM. This study was conducted over natural populations of waterhyacinth in Lakes Columbus and Aberdeen, MS over two growing seasons. Results indicate that the use of NDVI alone is a weak predictor of biomass; however, its combination with morphometric parameters like leaf area index enhanced predictive capabilities.In order to assess field herbicide treatments for waterhyacinth control and its consequent impact on native aquatic vegetation, lake-wide surveys were performed in Lake Columbus, MS using a point-intercept method. The herbicide assessed was 2,4-D which was applied aerially and by boats. Point-intercept surveys in a 400 by 400 grid of points aided with global positioning system (GPS) were performed before and after herbicide treatments. Obtained results indicate that the frequency of occurrence of waterhyacinth significantly decreased after herbicide treatments which consequently led to the reestablishment of native aquatic vegetation on the system.