Tesi sul tema "Harvesting"
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Elmes, John. "MAXIMUM ENERGY HARVESTING CONTROL FOROSCILLATING ENERGY HARVESTING SYSTEMS". Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3400.
Testo completoM.S.E.E.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering MSEE
Balouchi, Farouk. "Footfall energy harvesting : footfall energy harvesting conversion mechanisms". Thesis, University of Hull, 2013. http://hydra.hull.ac.uk/resources/hull:8433.
Testo completoSenli, Sukru. "Ethernet Energy Harvesting". Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-93853.
Testo completoMcGinley, Susan. "Harvesting Cotton Stalks". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1993. http://hdl.handle.net/10150/622348.
Testo completoGreen, P. L. "Nonlinear energy harvesting". Thesis, University of Sheffield, 2013. http://etheses.whiterose.ac.uk/3813/.
Testo completoCoates, Wayne. "Jojoba Harvesting Equipment". College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/215740.
Testo completoLittlefield, Joanne. "120º and Harvesting". College of Agriculture, University of Arizona (Tucson, AZ), 2007. http://hdl.handle.net/10150/295890.
Testo completoHaugen, Petter. "Automotive Energy Harvesting". Thesis, Mittuniversitetet, Institutionen för elektronikkonstruktion, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-37606.
Testo completoBarker, Simon Keith. "Resilient energy harvesting systems". Thesis, University of Newcastle Upon Tyne, 2012. http://hdl.handle.net/10443/1434.
Testo completoDyal, Kuljit Kaur. "Dendrimeric light-harvesting system". Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/11422/.
Testo completoShi, Weiwei. "Tree-Inspired Water Harvesting". Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/97604.
Testo completoDoctor of Philosophy
The purpose of this work is to investigate and characterize novel techniques for water harvesting that are inspired by natural trees. We are interested in two modes of water harvesting in particular: fog harps and synthetic trees. Fog harps were comprised of only vertical wires, inspired by the parallel structures of redwoods, which can capture and shed off fog droplets efficiently. Fog harps harvested more water than the traditional mesh nets, both under heavy fog and light fog conditions. Redwood-inspired fog harps have the high-efficient fog harvesting performance. They can be set up at coastal deserts to collect water from fog, where there is scarce rainfall but plenty of fog, like Chile, Peru and South Africa. Synthetic trees were designed with nanoporous disk (leaf) and tubes (xylem conduits), inspired by the transpiration process in natural trees. This transpiration-powered pump can lift water against the gravity at large scales, driven by the water evaporating from the nanopores. They can be used as the large-scale evaporation-driven hydraulic pump, for example, pumped storage hydropower, filtration, underground water extraction.
Triplett, Angela L. "Vibration-Based Energy Harvesting". University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1226614650.
Testo completoFarr, C. R. "Harvesting Potential and Progress". College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/204045.
Testo completoFarr, C. R. "Harvesting Progress in 1985". College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219812.
Testo completoINVERNIZZI, FABIO. "Human locomotion energy harvesting". Doctoral thesis, Università degli studi di Pavia, 2018. http://hdl.handle.net/11571/1214837.
Testo completoMothapo, Matholo Joyce. "Physico-chemical properties and selected nutritional components of Wild Medlar (Vangueria Infausta) fruit harvested at two haevesting time". Thesis, University of Limpopo, 2014. http://hdl.handle.net/10386/1391.
Testo completoWild medlar (Vangueria infausta subsp. infausta) is a popular indigenous fruit available and consumed by rural communities in Limpopo Province, South Africa. Inadequate post-harvest practices in indigenous fruit plants including V. infausta fruit forms major constrains in expanding their production. There is scanty information documented on neither objective nor subjective harvesting indices of indigenous fruit plants consumed by locals in sub-Saharan Africa. Thus, the objective of this study was to determine the effect of harvesting time on physico-chemical properties and selected nutritional composition of V. infausta fruit. Fruits were harvested twice, where two harvesting times were regarded as treatments and each tree as replication. The reduction for fruit weight, sugar content and sugar/acid ratio was highly significant (P ≤ 0.05), whereas for average fruit diameter, seed weight, acid ratio and pH content this may imply that the listed parameters are treatment which was non-significant (P ≤ 0.05). The treatment reduced P, K, Mn and Fe by 33%, 18%, 3% and 7%, respectively. On the other hand, treatments had no effect on N and Ca. The reduction of phosphorus was highly significant (P ≤ 0.05), whereas for N, K, Ca, Mn and Fe treatment impact was non-significant (P ≤ 0.05). Similarly, the treatment consistently reduced moisture content and increased dry matter and crude protein of V. infausta by 76%, 300% and 7%, respectively. The reduction of moisture content, increase in dry matter was highly significant (P ≤ 0.05), whereas crude protein treatment impact was non-significant (P ≤ 0.05). The data indicated that the best time to harvest V. infausta fruit was during January when fruits were cosmetically appealing and not wrinkled. This study demonstrated that there was less variation in some measured objective harvesting indices of V. infausta fruit harvested at two harvesting time. More work would be required to do physico-chemical properties and selected mineral elements analysis from wide growth habitat for conclusive recommendations.
Leclercq, Mathilde. "Harvesting energy from the sea". Thesis, KTH, Kraft- och värmeteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91881.
Testo completoTuck, Geoffrey N. "Optimal harvesting models for metapopulations /". Title page, contents and introduction only, 1994. http://web4.library.adelaide.edu.au/theses/09PH/09pht889.pdf.
Testo completoMannikko, Nancy Farm. "Technological innovation in forest harvesting /". This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-08252008-162946/.
Testo completoKwon, Dongwon. "Piezoelectric kinetic energy-harvesting ics". Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47571.
Testo completoCabiling, Alan P. "Ultra low-voltage energy harvesting". Thesis, Monterey, California: Naval Postgraduate School, 2013. http://hdl.handle.net/10945/37593.
Testo completoThe U.S. Navy has many opportunities to take advantage of energy sources that are usually wasted because these low power sources yield such low-voltages that a normal voltage converter is not efficient enough to harvest the energy. Low-voltage energy is available in many forms including solar, thermal, vibration, and electro-magnetic. The power that can be obtained from these sources on a small scale can be taken advantage of by using an ultra-low power boost converter that is specifically designed for energy harvesting applications. These energy sources with a very small footprint can be used in military and defense applications such as wireless sensor networks, industrial monitoring, and varieties of portable and wearable devices. The theory of power conversion, synchronous rectification, and maximum power point tracking is discussed. A discussion of the benefits of using an energy converter made specifically for energy harvesting is also covered. A commercially available energy harvester converter is simulated using a simulation program with integrated circuit emphasis, and a solar application is tested with hardware. The hardware experiments explore the startup sequence of the circuit, the switching profile of the converter, and a test of the circuits efficiency.
Harris, Peter. "Bistable laminates for energy harvesting". Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760884.
Testo completoFields, Noah S. "Interaction harvesting for document retrieval". Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32505.
Testo completoIncludes bibliographical references (p. 81-83).
Despite advances in search technology, few software systems have been developed which accurately categorize multimedia files. The most successful systems for searching images, sounds, or movies rely on keyword annotation to provide meaningful search terms for non-text documents. Unfortunately, such systems usually require the author to enter the keywords manually, a task that is commonly neglected, or is executed poorly. This thesis proposes an approach to document categorization called Interaction Harvesting, wherein systems establish document relationships based on organizational and curatorial cues, harvested from the mouse and click gestures of an online community. Specifically, the spatial and temporal proximity and placement of documents are taken as indicators of document similarity. We propose an expansion technique whereby such proximal documents exert weighted keyword influences on each other. We hypothesize that these approaches will form a document classification framework that relieves some of the difficulty of the annotation process, while providing keyword-equivalent retrieval performance.
by Noah S. Fields.
S.M.
Kim, Sangtae Ph D. Massachusetts Institute of Technology. "Electrochemically driven mechanical energy harvesting". Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/104181.
Testo completoCataloged from PDF version of thesis.
Includes bibliographical references (pages 113-120).
Efficient mechanical energy harvesters enable various wearable devices and may also act as auxiliary energy supply to isolated area. In this thesis, I present a novel class of mechanical energy harvesters based on stress-voltage coupling in electrochemically alloyed electrodes. The device consists of two identical Li-alloyed Si as electrodes, separated by electrolyte-soaked polymer membranes. Bending-induced asymmetric stresses generate chemical potential difference, driving lithium ion flux from the compressed to the tensed electrode to generate electric current. Unbending the device reverses the ion flux, generating electrical current in the opposite direction. The thermodynamic analyses reveal that the ideal energy-harvesting efficiency of this device is dictated by the Poisson's ratio of the electrodes. For the thin-film-based energy harvester used in this study, the device has achieved the overall efficiency of 0.6% and a generating capacity of 15%. The device also presents unique characteristics over the existing type of mechanical energy harvesters. Compared to piezoelectric or triboelectric generators, the prototype demonstrates low internal impedance of the order of 300[omega] as opposed to 100M[omega] in the other two types, and continuous electric current of the order of 3 seconds as opposed to 50ms in the other two types. From kinetics analysis, we show that the device's electric current generation is limited by lithium diffusion inside the LixSi electrode for sufficiently thick electrodes and by electrolyte diffusion for thin electrodes below 400nm. Tuning the current peak widths between 5s and 22s was demonstrated experimentally. The framework developed in the kinetics analyses also suggests that the device may be used as a spectroscopic tool to measure lithium diffusivity inside electrochemical alloys. The experimentally observed kinetics suggests lithium diffusivity on the order of 10-¹⁰cm² /s in Li₃.₁Si. The device demonstrates a practical use of stress-composition coupling in electochemically active alloys to harvest low-grade mechanical energies from various lowfrequency motions, such as everyday human activities. The analyses present the quantitative strategies to optimize the device in terms of its total energy output, kinetic behavior and ultimately the design principles for an energy harvester optimized for harvesting a specifically targeted frequency motion.
by Sangtae Kim.
Ph. D.
Apo, Daniel Jolomi. "Low Frequency Microscale Energy Harvesting". Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/49773.
Testo completoPh. D.
Männikkö, Nancy Farm. "Technological innovation in forest harvesting". Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/34764.
Testo completoMaster of Science
Anton, Steven Robert. "Multifunctional Piezoelectric Energy Harvesting Concepts". Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/27388.
Testo completoThe concept of multifunctional piezoelectric self-charging structures is explored throughout this work. The operational principle behind the concept is first described in which piezoelectric layers are directly bonded to thin-film battery layers resulting in a single device capable of simultaneously harvesting and storing electrical energy when excited mechanically. Additionally, it is proposed that self-charging structures be embedded into host structures such that they support structural load during operation. An electromechanical assumed modes model used to predict the coupled electrical and mechanical response of a cantilever self-charging structure subjected to harmonic base excitation is described. Experimental evaluation of a prototype self-charging structure is then performed in order to validate the electromechanical model and to confirm the ability of the device to operate in a self-charging manner. Detailed strength testing is also performed on the prototype device in order to assess its strength properties. Static three-point bend testing as well as dynamic harmonic base excitation testing is performed such that the static bending strength and dynamic strength under vibration excitation is assessed. Three-point bend testing is also performed on a variety of common piezoelectric materials and results of the testing provide a basis for the design of self-charging structures for various applications.
Multifunctional vibration energy harvesting in unmanned aerial vehicles (UAVs) is also investigated as a case study in this dissertation. A flight endurance model recently developed in the literature is applied to model the effects of adding piezoelectric energy harvesting to an electric UAV. A remote control foam glider aircraft is chosen as the test platform for this work and the formulation is used to predict the effects of integrating self-charging structures into the wing spar of the aircraft. An electromechanical model based on the assumed modes method is then developed to predict the electrical and mechanical behavior of a UAV wing spar with embedded piezoelectric and thin-film battery layers. Experimental testing is performed on a representative aluminum wing spar with embedded self-charging structures in order to validate the electromechanical model. Finally, fabrication of a realistic fiberglass wing spar with integrated piezoelectric and thin-film battery layers is described. Experimental testing is performed in the laboratory to evaluate the energy harvesting ability of the spar and to confirm its self-charging operation. Flight testing is also performed where the fiberglass spar is used in the remote control aircraft test platform and the energy harvesting performance of the device is measured during flight.
Ph. D.
Sours, Patrick J. "Maji Marwa: Rainwater Harvesting Initiative". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1563367729255742.
Testo completoXiong, Haocheng. "Piezoelectric Energy Harvesting for Roadways". Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/51361.
Testo completoPh. D.
Khodayari, Akram. "Harvesting energy from temperature variations". Lyon, INSA, 2009. http://theses.insa-lyon.fr/publication/2009ISAL0011/these.pdf.
Testo completoIn the framework of energy harvesting for microgenerators (for wireless and self powered electronics), this PhD investigates the capabilities of pyroelectric energy harvesting using ferroelectric materials. The energy source in this work is a time varying temperature. First, the energy harvesting using a linear pyroelectric material (PVDF film) was studied using Synchronized Switch Harvesting on Inductor (SSHI) nonlinear technique. This technique has been firstly developed in case of piezoelectric energy harvesting, and allows a very large effectiveness enhancement. This technique was applied for pyroelectric energy harvesting, and it has been compared with Standard technique. Efficiencies of these techniques were compared with Carnot cycle. The SSHI technique with pyroelectric material is in fact straightforward, but the harvested power and efficiency related to Carnot cycle are small. In order to improve the energy conversion, it was investigated phase transitions at which the pyroelectric and electrocaloric activity are maximum. For this purpose, phase transitions of relaxor Pb(Zn1/3Nb2/3)0. 955Ti0. 045O3 single crystals were used associated with the thermodynamic Ericsson cycle. The efficiency of the Ericsson cycle using the ferroelectric-ferroelectric (FE-FE) transition is much higher than techniques using linear properties of pyroelectric materials (gain of a factor of 100 compared to PVDF associated to SSHI technique). Finally, for a temperature variation of 10°C, harvested power using FE-FE transition and Ericsson cycle could reach 3 times the power that could be obtained using a thermoelectric harvester
Dias, Luís Filipe. "High-efficiency electromagnetic energy-harvesting". Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10180.
Testo completoNuma época em que os avanços tecnológicos se concretizam a um ritmo frenético, verifica-se uma desproporcional evolução das capacidades das baterias, essencialmente nos equipamentos móveis de uso comum. Por outro lado aumentam os dispositivos cuja localização remota torna a manutenção de baterias algo expensiosa e por vezes insustentável, tais como as Wireless Sensor Networks (WSN) O intuito deste trabalho prende-se não só com o aumento da eficiência de sistemas de recolha de energia de radiação electromagnética da banda dos 100MHz, como também com a introdução de novos métodos úteis à a sua análise. Paralelamente é ainda proposto um sistema de iluminação alimentado por circuitos de rectificação com um enfoque mais específico e menos relacionado com as suas eficiências. Ao nível dos melhores resultados obtidos para os circuitos de alta eficiência, estes foram alcançados por um circuito rectificador série simples, com valores de eficiência experimental de _ 45% para uma potência de entrada de 5dBm, gerando uma tensão de saída de _ 1:6V . Relativamente aos circuitos desenvolvidos para o sistema de iluminação foi possível, através de um multiplicador de tensão, gerar tensões DC ligeiramente acima de 8V para uma potência de entrada de 10dBm, desta forma conseguindo alimentar uma célula de três LEDs de baixo consumo. Os resultados obtidos destinam-se não apenas a apresentar conclusões inovadoras, mas também a fornecer ferramentas adequadas a posteriores desenvolvimentos de sistemas similares, servindo desta forma como um contributo de utilidade para a comunidade científica.
At a time when technological advances happen every day, a disproportional evolution of batteries capabilities has been verified, specially for mobile devices. On the other hand the number of devices whose remote location makes battery maintenance very expensive, Wireless Sensor Networks (WSN), is increasing. The objective of this work is not only to increase the eficiency of energy harvesting systems on the frequency of 100MHz, as it is introducing new methods for it's analysis. At the same time a no-cost illumination system, fed with more specific rectification systems, with less consideration for the eficiency is proposed here. As of the best results obtained for the high eficiency circuits, these were achieved for a simple series rectifier, with eficiencies around 45% for an input power of 5dBm, thus generating output voltages of _ 1:6V . The circuits developed for the lighting system, consisting in voltage multipliers, generated output voltage values around 8V for Pin = 10dBm, that is, enough to power up a low consuming 3 Light-Emitting Diode (LED)s cell. These obtained results are destined not only to present innovative conclusions, but also to provide adequate tools for subsequent developments of similar circuits, thus serving as a contribute for the scientific community.
James, Ashley. "Oxide thermoelectric energy harvesting materials". Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/9277.
Testo completoChrobok, Viktor. "Optimization of Harvesting Natural Resources". Doctoral thesis, Vysoká škola ekonomická v Praze, 2008. http://www.nusl.cz/ntk/nusl-196942.
Testo completoSabaawi, Ahmed Mohammed Ahmed. "Nanoantennas for solar energy harvesting". Thesis, University of Newcastle upon Tyne, 2015. http://hdl.handle.net/10443/2921.
Testo completoCluff, C. Brent. "Water Harvesting in Arid Lands". Water Resources Research Center. The University of Arizona, 1987. http://hdl.handle.net/10150/306468.
Testo completoThe use of water harvesting systems in arid lands offers the potential of making lands productive that are now largely unusable due to lack of water for domestic livestock or agricultural use. As long as there is rainfall a water harvesting system can be designed to collect that rainfall and store it until it can be used for beneficial use. The water harvesting system consists of a catchment and a storage facility. If the water is to be used for agriculture it would also include an agricultural area. The agricultural area could be located within the catchment area or in a separate nearby area. Many different treatments have been tested for use in catchment construction. These treatments increase the runoff by decreasing the permeability of the surface and or reducing the time the water stays on the surface or amount of water trapped on the surface. A list of the more promising treatments in order of their increasing cost, are: (1) Shaped compacted-earth; (2) sodium-treated shaped compacted-earth; (3) wax-treated shaped compacted-earth; (4) gravel-covered plastic; (5) fiberglass-asphalt chipcoated; (6) asphalt-plastic-asphalt chipcoated; (7) rubberized-asphalt chipcoated; and (8) reinforced-mortar-covered plastic. The use of compartmented reservoirs make storage of water more efficient. Evaporation and in some cases seepage losses are reduced using the compartmented reservoir by keeping the water concentrated into a volume with as small a surface area as possible. This method of storage when combined with the collection of runoff from a natural surface or with one that is inexpensively treated makes it practical to provide water for supplemental irrigation. This combination is called a water harvesting agrisystem. Concentration of water in a compartmented reservoir can be accomplished in flat terrain using a pump. If the water is being used at a fast enough rate concentration can also be accomplished by selective removal. Alternatively with topography of a sufficient grade, concentration can be accomplished by gravity. Evaporation control on the compartmented reservoir can be improved by placing an evaporation control barrier on the "last" compartment, the one in which water is concentrated and has water in it the longest time. This enhances the value of the evaporation control barrier and increases the dependable water supply. A computer model has been developed to help in the design of the water harvesting systems including agrisystems with compartmented reservoirs. This program fits on portable personal computers and can thus be taken by the designer to a field location to develop an optimum design at a minimum cost. The model can be improved through calibration in a given area as systems are installed and data collected.
Waterfall, Patricia. "Harvesting Rainwater for Landscape Use". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/144824.
Testo completoIn the arid Southwest, rainfall is scarce and evapotranspiration rates are high. Only natives and some desert-adapted plants can live on 10 or 11 inches of annual rainfall. Other plants require some supplemental irrigation and harvesting rainwater can reduce the use of drinking water for landscape irrigation. This publication discusses the water requirements for some plants and the way to collect rainwater. Its topics include: - Water Harvesting System Components - Simple Water Harvesting System Design and Construction - Complex Water Harvesting Systems
Waterfall, Patricia. "Harvesting Rainwater for Landscape Use". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2006. http://hdl.handle.net/10150/144825.
Testo completoSecond Edition, October 2004
In the arid Southwest, rainfall is scarce and evapotranspiration rates are high. Only natives and some desert-adapted plants can live on 10 or 11 inches of annual rainfall. Other plants require some supplemental irrigation and harvesting rainwater can reduce the use of drinking water for landscape irrigation. This publication discusses the water requirements for some plants and the way to collect rainwater. Its topics include: - Water Harvesting System Components - Simple Water Harvesting System Design and Construction - Complex Water Harvesting Systems
Farr, C. "Progress of Upland Cotton Harvesting". College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/204825.
Testo completoYazici, Erol 1961. "Pneumatic harvesting of jojoba seeds". Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277230.
Testo completoTsangarides, Constantinos. "Thermoelectric energy harvesting in displays". Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/268222.
Testo completoMaťaš, Marek. "Energy harvesting pro letecké aplikace". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-231031.
Testo completoFofana, Alpha, e Carl Mossberg. "Energy harvesting from ambient WiFi energy : A method of harvesting and measuring ambient WiFi energy". Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-257860.
Testo completoMed den nuvarande utvecklingen inom trådlös teknik och IoT-domänen har efterfrågan på elektroniska applikationer med låg effekt ökat och en av utmaningarna är att hitta effektiva och hållbara sätt att driva dessa typer av enheter. Syftet med detta projekt var att undersöka frågan hur vi skördar radiovågsenergi och kan vi skörda tillräckligt mycket med energi för att den ska vara användbar i en applikation. I ett typiskt kontor finns fler källor till radiovågor, däribland WiFi som antas ha en hög nyttjandegrad. Projektet valde att inrikta sig på WiFi bandet och undersöka om det går att utvinna tillräckligt med energi där.Projektet strävade efter att leverera en färdig produkt med alla ingående delar, en antenn, en likriktare, en lagringsenhet och ett matchningsnätverk för att anpassa antenn och likriktare till varandra. För att undersöka hur mycket energi som finns att skörda gjordes först beräkningar och sedan mätningar i bland annat ett typiskt kontor. Det konstaterades att det rör sig om väldigt låga nivåer och betonas att de apparater som använder WiFi klarar av att känna av signaler som är långt mycket lägre än de som krävs för att kunna utvinna energi. Detta innebär alltså att apparaterna kan kommunicera felfritt samtidigt som energiinnehållet är så lågt att det inte går att utvinna någon energi.Projektet ägnar stor del åt att optimera den impedansmatchning som måste ske mellan antenn och likriktare för att största möjliga effektutbyte ska kunna ske. Basen är ett kretskort med ett typiskt impedansnätverk och genom beräkningar, simuleringar och experiment tas en prototyp fram. För att kunna analysera resultaten används en mikrokontroller som tar de analoga värdena, omvandlar dem till digitala och skickar dem till en PC för analys.Mätningar gjordes i en kontorsmiljö och den maximala mängden energi som gick att utvinna var 350 mJ på 24 timmar. Energin lagrades i en superkondensator och bedöms vara tillräcklig för att driva en lågenergisensor i ca 30 sekunder.
Daily, Cado, e Cyndi Wilkins. "RainScapes". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011. http://hdl.handle.net/10150/144821.
Testo completoRainScapes are the ultimate in water efficient landscaping. RainScapes are beautiful landscapes that once established rely entirely on rain and stormwater (gray water too if available)while preserving tap water for indoor and drinking water needs.
Vennitti, Andrea. "Analisi dei sistemi per l'energy harvesting". Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16508/.
Testo completoMateu, Sáez Maria Loreto. "Energy harvesting from human passive power". Doctoral thesis, Universitat Politècnica de Catalunya, 2009. http://hdl.handle.net/10803/48637.
Testo completoThe trends in technology allow the decrease in both size and power consumption of complex digital systems. This decrease in size and power gives rise to the concept of wearable devices which are integrated in everyday personal belongings like clothes, watch, glasses, et cetera. Power supply is a limiting factor in the mobility of the wearable device which gets restricted to the lifetime of the battery. Furthermore, due to the costs and inaccessible locations, the replacement or recharging of batteries is often not feasible for wearable devices integrated in smart clothes. Wearable devices are devices distributed in personal belongings and thus, an alternative for powering them is to harvest energy from the user. Therefore, the energy can be harvested, distributed and supplied over the human body. Wearable devices can create, like the sensors of a Wireless Sensor Network (WSN), a Body Area Network. A study of piezoelectric, inductive and thermoelectric generators that harvest passive human power is the main objective of this thesis. The physical principle of an energy harvesting generator is obviously the same no matter whether it is employed with an environmental or human body source. Nevertheless, the limitations related to low voltage, current and frequency levels obtained from human body sources bring new requirements to the energy harvesting topic that were not present in the case of the environment sources. This analysis is the motivation for this thesis. The type of input energy and transducer form a tandem since the election of one imposes the other. It is important that measurements are done in different parts of the human body while doing different physical activities to locate which positions and activities produce more energy. The mechanical coupling between the transducer and the human body depends on the location of the transducer and the activity that is done. A specific design taking this into account can increase more than a 200% the efficiency of the transducer as has been demonstrated with piezoelectric films located in the insoles of shoes. Acceleration measurements have been performed in different body locations and different physical activities, in order to quantify the amount of available energy associated with usual human movements. A system-level simulation has been implemented modeling the elements of an energy self-powered system. Physical equations have been used for the transducer in order to include the mechanical part of the system and electrical and behavioral models for the rest of the components. In this way, the process of the design of the complete application (including the load and an energy storage element when it is necessary) is simplified to achieve the expected requirements. Obviously, the load must be a low power consumption device as for example a RF transmitter. In this case, it is preferable to operate it in a discontinuous way without a battery as it is deduced from simulation results obtained. However, the evolution in low power transmission modules can change this conclusion depending mostly on the evolution of the power consumption in stand-by mode and the configuration time in transmission operation. It has been deduced from the analysis of inductive generators that time-domain analysis allows to calculate some magnitudes that are not available in frequency domain. For example, the maximum power can be calculated in frequency domain, but for energy harvesting applications it is more interesting to know the value of the recovered energy during a certain time, or the average power since the power generated by human activities can be highly discontinuous. It has been demonstrated that energy harvesting transducers are able to supply power to present-day low power electronic devices as was demonstrated with a RF transmitter powered by a thermogenerator that employs the temperature gradient between human body and the environment (3-5 K) and that it is able to sense and transmit data once every second.
Halfvardsson, Terese, Jagoda Maracic e Peter Sjöberg. "Knowledge Harvesting from International Joint Ventures". Thesis, Kristianstad University College, Department of Business Administration, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-3263.
Testo completoThis dissertation explores and analyses factors which could facilitate Knowledge
Harvesting, and also how important it is for the parent companies. Knowledge
Harvesting is one of the knowledge processes within an international joint venture
network that has not received much attention from the academic community. After
relevant review of the literature in the area of international joint ventures and
knowledge management, the authors of the dissertation created a model. The model
consists of five factors: Motive, Absorptive capacity, Knowledge characteristics,
Trust, and Control. Eight hypotheses are formulated in order to test the model. The
empirical study is concentrated on Swedish companies involved in an international
joint venture with a foreign company. A deductive approach is chosen in order to
answer the research questions, and primary data is collected using an online survey.
The results of the questionnaire are analysed in a descriptive manner and several
conclusions are drawn.
Ersoy, Kurtulus. "Piezoelectric Energy Harvesting For Munitions Applications". Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613589/index.pdf.
Testo completoand ORCAD PSPICE®
, and finite element method models generated in ATILA®
. Optimum energy storage methods are considered.
Vignati, Stefano. "Solutions for Indoor Light Energy Harvesting". Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-108083.
Testo completoAlaei, Zohreh. "Power Enhancement in Piezoelectric Energy Harvesting". Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-188956.
Testo completoNordwall, Fredrik. "Stream fish population response to harvesting /". Umeå : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2000. http://epsilon.slu.se/avh/2000/91-576-5867-6.pdf.
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