4 research outputs found

    Evaluation of Mater Bi and Polylactic Acid as materials for biodegradable innovative mini-radiosondes to track small scale fluctuations within clouds

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    Turbulence plays an important part in determining the chemical and physical processes, on both the micro- and macro-scales, whereby clouds are formed and behave. However, exactly how these are linked together and how turbulence impacts each of these processes is not yet fully understood. This is partly due to a lack of in-situ small scale fluctuation measurements due to a limitation in the available technology. It is in this context that the radiosondes, for which the material characterisation is presented in this paper, are being developed to generate a Lagrangian set of data which can be used to improve the ever-expanding knowledge of atmospheric processes and, in particular, the understanding of the interaction between turbulence and micro-physical phenomenologies inside clouds (www.complete-h2020network.eu). Specifically, the materials developed for the balloons are discussed in further detail within this paper. Mater Bi and polylactic acid are the two common biodegradable thermoplastics that were used initially to make the balloons. To tailor their properties, the balloons were then coated with carnauba wax blended with either pine resin or SiO2 nanoparticles. The properties such as hydrophobicity, toughness, elasticity and helium gas permeability are investigated and improved in order to keep the density of the radiosondes as constant as possible for a couple of hours. This will allow them to float inside and outside clouds on an isopycnic surface, to measure various properties such as velocity, temperature, pressure and humidity by means of solid state sensors and to transmit them to receivers on Earth. Tests have been made under a rigorous metrological approach comparing the 6 new materials with two reference balloon materials, latex and mylar. It was found that Mater Bi with the two carnauba wax coatings is the most suited though its roughness and water vapour permeability should be improved

    Evaluation of Mater Bi and Polylactic Acid as materials for biodegradable innovative mini-radiosondes to track small scale fluctuations within clouds

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    Turbulence plays an important part in determining the chemical and physical processes, on both the micro- and macro-scales, whereby clouds are formed and behave. However, exactly how these are linked together and how turbulence impacts each of these processes is not yet fully understood. This is partly due to a lack of in-situ small scale fluctuation measurements due to a limitation in the available technology. It is in this context that the radiosondes, for which the material characterisation is presented in this paper, are being developed to generate a Lagrangian set of data which can be used to improve the ever-expanding knowledge of atmospheric processes and, in particular, the understanding of the interaction between turbulence and micro-physical phenomenologies inside clouds (www.complete-h2020network.eu). Specifically, the materials developed for the balloons are discussed in further detail within this paper. Mater Bi and polylactic acid are the two common biodegradable thermoplastics that were used initially to make the balloons. To tailor their properties, the balloons were then coated with carnauba wax blended with either pine resin or SiO_2 nanoparticles. The properties such as hydrophobicity, toughness, elasticity and helium gas permeability are investigated and improved in order to keep the density of the radiosondes as constant as possible for a couple of hours. This will allow them to float inside and outside clouds on an isopycnic surface, to measure various properties such as velocity, temperature, pressure and humidity by means of solid state sensors and to transmit them to receivers on Earth. Tests have been made under a rigorous metrological approach comparing the 6 new materials with two reference balloon materials, latex and mylar. It was found that Mater Bi with the two carnaubua wax coatings is the most suited.

    Floating Dropsondes with DGPS Receiver for Real-time Typhoon Monitoring

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    在本研究中,我們利用差分全球定位系統技術即時監測颱風,提高投落送定位的準確性,以量測颱風風場。並利用空飄氣球附載GPS接收機,以延長投落送之滯空時間,以觀察颱風的形成與變化。 模擬佈署投落送空飄氣球時,考慮降雨帶之分布、距海面之高度等重要因素,並以莫拉克颱風及卡翠娜颶風為例來驗證此一技術。An approach is proposed for real-time monitoring of typhoon evolution, which is based on floating dropsondes bearing differential global positioning system (DGPS) receiver. A practical typhoon model for Typhoon Morakot and Hurricane Katrina is adopted to verify this novel approach. The deployment plan of dropsondes are also simulated to assess its feasibility

    Remote Sensing

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    This dual conception of remote sensing brought us to the idea of preparing two different books; in addition to the first book which displays recent advances in remote sensing applications, this book is devoted to new techniques for data processing, sensors and platforms. We do not intend this book to cover all aspects of remote sensing techniques and platforms, since it would be an impossible task for a single volume. Instead, we have collected a number of high-quality, original and representative contributions in those areas
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