Measurement of atmospheric carbon dioxide abundance on board unmanned aircraft challenges and applications

In this dissertation the COmpact Carbon dioxide analyser for Airborne Platforms (COCAP) is presented. COCAP measures the abundance of carbon dioxide (CO2) in ambient air as well as air temperature, humidity and pressure, and is specifically designed for the use on board small unmanned aircraft systems (UASs). Accurate CO2 measurements are ensured by extensive calibration in an environmental chamber, by regular calibration in the field and by chemical drying of sampled air. In addition, the analyser is equipped with a custom-built, lightweight thermal stabilisation system that reduces the influence of ambient temperature changes on the CO2 sensor by two orders of magnitude. The robustness of COCAP under varying environmental conditions has been verified through a series of tests both in the lab and in the field. As a first application of the newly developed instrument, COCAP was used to constrain the nocturnal carbon dioxide emission of an ecosystem based on the nocturnal boundary layer (NBL) budget method. The NBL budgets were calculated from a series of CO2 profiles measured by COCAP on board a UAS during the course of two nights. The fluxes obtained in the pilot study are plausible and insensitive to experimental uncertainties. Given the versatility and moderate cost of UASs and their minimal infrastructure requirements, this innovative sampling technique makes the NBL budget method for the quantification of surface fluxes more accessible and cost-effective. This work demonstrates how the potential of UASs for measuring trace gases in theatmosphere can be exploited, thus opening up new possibilities for atmospheric research.In dieser Dissertation wird ein kompakter Kohlendioxidanalysator für Flugsysteme (COmpact Carbon dioxide analyser for Airborne Platforms, COCAP) vorgestellt. COCAP misst den Gehalt an Kohlendioxid (CO2), die Temperatur, die Feuchte und den Druck der Umgebungsluft und ist speziell für den Einsatz auf kleinen unbemannten Luftfahrtsystemen ausgelegt. Genaue Kohlendioxidmessungen werden durch umfangreiche Kalibrierungen in einer Klimakammer, regelmäßige Kalibrierungen während des Feldeinsatzes und durch chemische Trocknung der Probenluft sichergestellt. Darüber hinaus enthält das Messsystem einen speziell entwickelten Temperaturregler mit geringer Masse, der den störenden Einfluss äußerer Temperaturänderungen auf den CO2-Sensor um zwei Größenordnungen verringert. COCAPs Robustheit gegenüber wechselnden Umgebungsbedingungen wurde in einer Reihe von Tests im Labor und im Feld nachgewiesen. COCAPs erster wissenschaftliche Einsatz diente der Abschätzung nächtlicher Kohlendioxidflüsse mithilfe von Budgets der nächtlichen Grenzschicht (nocturnal boundary layer, NBL). Diese NBL-Budgets wurden aus CO2-Profilen errechnet, welche COCAP während einer Reihe von Flügen mit einem unbemannten Luftfahrtsystem im Verlauf zweier Nächte aufzeichnete. Die in dieser Pilotstudie ermittelten Flüsse sind plausibel und robust gegenüber experimentellen Unsicherheiten. Angesichts der Vielseitigkeit und der moderaten Kosten unbemannter Luftfahrtsysteme sowie ihrer minimalen Ansprüche an die Infrastruktur im Feld eröffnet diese innovative Messstrategie eine vergleichsweise einfache und günstige Möglichkeit, Flüsse durch NBL-Budgets zu bestimmen. Diese Arbeit zeigt auf, wie das Potenzial unbemannter Luftfahrtsysteme für Spurengasmessungen genutzt werden kann, wodurch sich neue Perspektiven für die Atmosphärenforschung ergeben

Experimental study and exergy analysis of photovoltaic-thermoelectric with flat plate micro-channel heat pipe

Effective cooling of the photovoltaic can enhance electrical conversion efficiency of a photovoltaic system. The combination of photovoltaic and thermoelectric generator provides unique advantages because of their complementary characteristics. In addition, hybrid photovoltaic-thermoelectric can utilize a wider solar spectrum thereby harvesting more energy from the sun. Heat pipes are passive devices that can transfer heat efficiently over a long distance. Therefore, this study presents an experimental investigation and exergy analysis of a photovoltaic-thermoelectric with flat plate micro-channel heat pipe. The experiment is performed in a laboratory using a solar simulator and water-cooling is used for the thermoelectric generator. The effect of thermoelectric load resistance, micro-channel heat pipe back insulation and solar radiation on the performance of the hybrid system is presented and a comparison with a photovoltaic only system is provided. Results show that the hybrid system provides an enhanced performance compared to the photovoltaic only system and absence of insulation behind the micro-channel heat pipe enhances electrical performance of the hybrid system. Furthermore, results show the feasibility of the hybrid system for generating electricity and small hot water. This study will provide valuable guidance for design of photovoltaic-thermoelectric systems with heat pipe and verifies the feasibility of such systems

Healthy climate and energy savings: using thermal ceramic panels and solar thermal panels in mediterranean housing blocks

Radiant surface conditioning systems based on capillary tube mats not only provide high standards of comfort, but they also generate substantial energy savings. These systems allow for using renewable energies such as solar thermal panels because they function with water at moderate temperatures¿lower in winter and higher in summer¿compared to fan-coil systems or hot water radiator systems. Moreover, in summer, they can be combined with solar cooling systems based on lithium chloride or absorption systems based on lithium bromide, which enable the cooling of water at 15¿16 C by means of solar thermal panel energy collection. This further reduces the annual energy. The purpose of this study was to examine the application of thermal ceramic panels (TCP) containing prolipropylen (PPR) capillary tube mats, in residential buildings in the Spanish Mediterranean. The water distribution system was set up individually from a heat pump and was combined with a community system of solar thermal panels. After monitoring a home over a complete one-year cycle, the annual energy demand was quantified through simulations, based on both the radiant system and the VRV system, as well as in combination with a thermal solar panel system. TCP panels reduced the annual energy demands by 31.48%, and the additional investment cost of  11,497 could be amortized over 23.31 years. The combination of TCP panels with 18.5 m2 of solar thermal panels reduced the annual energy demand by 69.47%, and the inv

Healthy Climate and Energy Savings: Using Thermal Ceramic Panels and Solar Thermal Panels in Mediterranean Housing Blocks

Radiant surface conditioning systems based on capillary tube mats not only provide high standards of comfort, but they also generate substantial energy savings. These systems allow for using renewable energies such as solar thermal panels because they function with water at moderate temperatures—lower in winter and higher in summer—compared to fan-coil systems or hot water radiator systems. Moreover, in summer, they can be combined with solar cooling systems based on lithium chloride or absorption systems based on lithium bromide, which enable the cooling of water at 15–16 °C by means of solar thermal panel energy collection. This further reduces the annual energy. The purpose of this study was to examine the application of thermal ceramic panels (TCP) containing prolipropylen (PPR) capillary tube mats, in residential buildings in the Spanish Mediterranean. The water distribution system was set up individually from a heat pump and was combined with a community system of solar thermal panels. After monitoring a home over a complete one-year cycle, the annual energy demand was quantified through simulations, based on both the radiant system and the VRV system, as well as in combination with a thermal solar panel system. TCP panels reduced the annual energy demands by 31.48%, and the additional investment cost of €11,497 could be amortized over 23.31 years. The combination of TCP panels with 18.5 m2 of solar thermal panels reduced the annual energy demand by 69.47%, and the investment of €20,534 of additional cost could be amortized over 15.67 years. The energy consumptions of installation elements were also comparatively quantified.This study was part of a research project led by the Centre for Industrial Technical Development (CDTI), called “Research and design of constructive solutions for the energy improvement of buildings”, reference IDI-20110240, co-financed by the European Regional Development Fund (ERDF), requested for the period 2011–2013 by ECISA, General Company of Constructions S.A., based on an agreement (Reference ECISA1-10Y) with the University of Alicante

Small-scale photovoltaic systems: investigation of energy harvesting applications and development of a phone charging system

Dissertação de mestrado em Engenharia Física, apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra.Esta tese aborda o desenvolvimento de um sistema de medida de características de módulos fotovoltaicos orgânicos, bem como uma aplicação de baixo custo destes módulos, para o carregamento de telemóveis. Todo o trabalho foi realizado em estágio, numa empresa que produz e comercializa módulos fotovoltaicos orgânicos, sediada em Cambridge, no Reino Unido – Eight19. O sistema de medida tem o intuito de permitir uma avaliação do desempenho dos módulos fotovoltaicos em situações de fraca iluminação, com a possibilidade de serem utilizados para energy harvesting. Este sistema baseia-se num microcontrolador que, através de um circuito electrónico de interface com o módulo fotovoltaico, mede a corrente de curto-circuito e a tensão em circuito aberto do mesmo, permitindo um cálculo posterior da sua potência máxima. São apresentados alguns resultados deste sistema em diferentes condições de iluminação. Quanto à aplicação de carregamento de telemóveis, é primeiro efectuado um estudo acerca da energia solar disponível em África, que corresponde ao mercadoalvo da empresa onde este trabalho foi realizado. De seguida são planeados e desenvolvidos protótipos para esta aplicação, baseados em diferentes hipóteses de aproveitamento de energia, permitindo a sua comparação. Palavras-chave: módulos fotovoltaicos; aplicação de baixo custo; carregamento de dispositivos móveis; energy harvestin

Reef rescue marine monitoring program quality assurance and quality control manual 2013/2014

The Reef Rescue Marine Monitoring Program Quality Assurance and Quality Control (QA/QC) Manual summarises the monitoring methods and procedures used in the Program. Detailed sampling manuals, standard operating procedures, analytical procedures and other details are provided as appendices

Field Measurements of Terrestrial and Martian Dust Devils

Surface-based measurements of terrestrial and martian dust devils/convective vortices provided from mobile and stationary platforms are discussed. Imaging of terrestrial dust devils has quantified their rotational and vertical wind speeds, translation speeds, dimensions, dust load, and frequency of occurrence. Imaging of martian dust devils has provided translation speeds and constraints on dimensions, but only limited constraints on vertical motion within a vortex. The longer mission durations on Mars afforded by long operating robotic landers and rovers have provided statistical quantification of vortex occurrence (time-of-sol, and recently seasonal) that has until recently not been a primary outcome of more temporally limited terrestrial dust devil measurement campaigns. Terrestrial measurement campaigns have included a more extensive range of measured vortex parameters (pressure, wind, morphology, etc.) than have martian opportunities, with electric field and direct measure of dust abundance not yet obtained on Mars. No martian robotic mission has yet provided contemporaneous high frequency wind and pressure measurements. Comparison of measured terrestrial and martian dust devil characteristics suggests that martian dust devils are larger and possess faster maximum rotational wind speeds, that the absolute magnitude of the pressure deficit within a terrestrial dust devil is an order of magnitude greater than a martian dust devil, and that the time-of-day variation in vortex frequency is similar. Recent terrestrial investigations have demonstrated the presence of diagnostic dust devil signals within seismic and infrasound measurements; an upcoming Mars robotic mission will obtain similar measurement types

Testing trait plasticity over the range of spectral composition of sunlight in forb species differing in shade tolerance

Although sunlight is essential for plant growth and development, the relative importance of each spectral region in shaping functional traits is poorly understood, particularly in dynamic light environments such as forest ecosystems. We examined responses of 25 functional traits from groups of 11 shade-intolerant and 12 understorey shade-tolerant forb species grown outdoors under five filter treatments differing in spectral transmittance: (a) transmitting c. 95% of solar radiation (280-800 nm); (b) attenuating ultraviolet-B (UV-B); (c) attenuating all UV; (d) attenuating all UV and blue light; (e) attenuating all UV, blue and green light. Our results show that UV-B radiation mainly affected the biochemical traits but blue light mainly affected the physiological traits irrespective of functional strategy, whereas green light affected both sets of traits. This would suggest that differentiation among suites of functional trait responses proceeds according to light quality. Biomass accumulation was significantly increased by UV-A radiation (contrasting treatment [b] vs. [c]) among shade-intolerant but decreased by blue light among shade-tolerant species; green and red light affected whole-plant morphological development differently according to functional groups. Shade-tolerant species were more plastic than shade-intolerant species in response to each spectral region that we examined except for UV-B radiation. Synthesis. Our results show that differences in the spectral composition of sunlight can drive functional trait expression irrespective of total irradiance received. The different responses of functional traits between functional groups imply that shade-tolerant and intolerant species have adapted to utilize spectral cues differently in their respective light environments.Peer reviewe

Design And Implementation Of Human Crowd Density Estimation System With Energy Harvesting In Wireless Sensor Network Platform

Kepadatan yang tinggi dalam khalayak ramai boleh menjadi berbahaya kerana wujudnya potensi untuk pergerakan sekumpulan manusia secara tiba-tiba yang menyebabkan rempuhan dalam kes kecemasan. Untuk mengurangkan kecederaan mahupun kehilangan nyawa dalam kemalangan yang berkaitan dengan isu kepadatan manusia, sistem pengawasan kepadatan manusia berdasarkan frekuensi radio telah dibangunkan sebagai satu alat keselamatan. Sistem yang didapati pada masa kini mempunyai keupayaan pengawasan yang terhad; saiz pengawasan khalayak yang rendah, jarak pengesanan yang rendah, keperluan bilangan alat komunikasi yang tinggi dan jangka hayat operasi yang terhad. Faktor-faktor ini memberi kesan secara langsung kepada unsur praktikal dan ketepatan sistem penganggaran kepadatan manusia tersebut. Untuk mengurangkan kelemahan keupayaan pengawasan, satu sistem untuk mengesan kepadatan khalayak diusulkan berdasarkan kepada teknologi ZigBee dan rangkaian pengesan tanpa wayar yang meningkatkan jarak pengesanan khalayak kepada 30 m dengan hanya satu nod diperlukan setiap 37.5 m2. Hal ini dicapai tanpa mengurangkan bilangan khalayak (50 orang) yang boleh dikesan oleh sistem. Untuk menambahbaik ketepatan anggaran, kesan khalayak terhadap isyarat diselidik menggunakan kaedah statistik ‘One-way Analysis of Variance’ dan ‘Design of Experiments’. Hasil dapatan mengesahkan saiz khalayak memberi kesan yang paling besar terhadap kelemahan isyarat. Untuk interaksi di antara sifat-sifat khalayak, didapati saiz khalayak bersama bilangan alat penerima dan bentuk khalayak bersama bilangan alat penerima memberi kesan signifikan terhadap kekuatan isyarat. Faktor-faktor ini kemudian dimasukkan ke dalam algoritma H-CDE yang diusulkan. Algoritma pengesanan khayalak ini dan pengelasannya menunjukkan purata sebanyak 71.2 peratus ketepatan dalam mengenalpasti tahap kepadatan khalayak yang juga dapatan terbaik berbanding algoritma lain. Untuk mengatasi masalah kuasa yang terhad, mekanisma tuaian tenaga solar diperkenalkan ke dalam sistem H-CDE untuk memanjangkan jangka hayat operasi pengawasan. Kajian menunjukkan mekanisma tuaian tenaga ini mampu untuk memanjangkan operasi sistem pengawasan secara berterusan jika sistem ini mendapat paling kurang 5 hingga 6 jam pendedahan kepada sinaran matahari setiap 33 jam kitaran. Sumbangan kajian ini ialah pada penambahbaikan sistem berdasarkan teknologi frekuensi radio untuk mengesan kepadatan khalayak, penambahbaikan pada ketepatan penganggaran kepadatan khalayak yang didokongi oleh analisis statistik dan lanjutan operasi sistem melalui mekanisma tuaian tenaga. __________________________________________________________________________________ A crowd with high density can be dangerous due to the potential of a sudden surge of large moving bodies causing stampede in cases of emergencies. To mitigate casualties in crowd-related disaster, radio frequency-based crowd density estimation and monitoring system is being developed as a safety tool. Current systems have limited monitoring capabilities; low size of crowd monitored, low detection range, high number of transceivers required and finite operational lifetime. These factors directly influence the practicality and prediction accuracy of the system. To mitigate the limited sensing capability, a human crowd density estimation (H-CDE) system based on ZigBee and wireless sensor network technology is proposed that increases the crowd detection range to 30 m with only one transmission node required every 37.5 m2. This is achieved without sacrificing the amount of crowd detectable by the system (50 people). To improve the estimation accuracy, the effect of crowd on signal propagation is investigated using One-way Analysis of Variance and Design of Experiments statistical methods. The results verified that the crowd size significantly affects the signal attenuation. In the interactions between the crowd properties, crowd size * number of receiver and crowd pattern * number of receiver were found to significantly affect signal propagation. These factors are then integrated into the proposed H-CDE algorithm. The H-CDE algorithm and its crowd classification yielded an average of 71.2 % accuracy in identifying the level of crowd density, which is the best compared to other algorithms found in the literature. To solve the finite power problem, a solar energy harvesting mechanism is introduced into the H-CDE system to extend the operation of the monitoring system. It is demonstrated that the proposed energy harvesting mechanism could operate perpetually, given that the system is exposed to good sunlight at least for 5 to 6 hours in every 33-hour cycle. The contribution of the research is on the improved RF-based crowd density detection system, improved crowd estimation accuracy which is backed by statistical analysis and extension of its operations through the energy harvesting mechanism