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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Quantifying the performance of natural ventilation windcatchers

Jones, Benjamin Michael January 2010 (has links)
The significant energy consumption of non- domestic buildings has led to renewed interest in natural ventilation strategies that utilise the action of the wind, and the buoyancy of hot air. One natural ventilation element is the Windcatcher, a roof mounted device that works by channelling air into a room under the action of wind pressure, whilst simultaneously drawing air out of the room by virtue of a low pressure region created downstream of the element. A significant number of Windcatchers are fitted in UK schools where good indoor air quality is essential for the health and performance of children. The performance of a ventilation system in a school classroom is determined by its ability to provide ventilation in accordance with UK government ventilation, air quality, and acoustic requirements. However, there is only limited performance data available for a Windcatcher, particularly when operating in-situ. Accordingly, this thesis investigates the performance of a Windcatcher in three ways: First, a semi-empirical model is developed that combines an envelope flow model with existing experimental data. Second, measurements of air temperature, relative humidity, carbon dioxide, and noise levels in school classrooms are assessed over summer and winter months and the results compared against UK Government requirements. Finally, air flow rates are measured in twenty four classrooms and compared against the semi-empirical predictions. The monitoring reveals that air quality in classrooms ventilated by a Windcatcher has the potential to be better than that reported for conventional natural ventilation strategies such as windows. Furthermore, an autonomous Windcatcher is shown to deliver the minimum ventilation rates specified by the UK Government, and when combined with open windows a Windcatcher is also capable of providing the required mean and purge ventilation rates. These findings are then used to develop an algorithm that will size a Windcatcher for a particular application, as well as helping to improve the ventilation strategy for a building that employs a Windcatcher.
72

Zero energy buildings : theoretical investigation and applied analysis for the design of zero energy building in hot climate countries

Pittakaras, Paris January 2015 (has links)
Problem description: The buildings consume significant amounts of energy and are therefore major contributors to the overall CO2 emissions at the present time. The reduction of energy consumption in buildings is a major contribution to the overall control of global warming and to the improvement of sustainability. These reductions are essential as the world faces economic and energy crisis. An important key to the world’s energy problem is sustainable development. Taking the island of Cyprus as a case study, this thesis explores the different building categories and types, analyse building energy models and propose guidelines for the success development of Zero energy buildings in hot climates without compromising the comfort levels of the buildings. Purpose: The ultimate target is to be able to design and operate a building which requires no fossil fuel consumption – the so called “zero energy/carbon (emissions)” building. It is important for all countries to set a national goal in order to achieve zero energy consumption in the building sector and reduce the energy demands. Method: Through the theoretical research the project explored the causes of the problem of building energy, the different types of buildings, the definitions of zero energy buildings in various countries, regulations and standards concerning the buildings energy and all the available technology, methods and materials that can be used in the building sector. In this way the analysis presents the needs of the project and the point of focus during the practical part of the research with simulation of building models. The practical part of the project was the simulation of different building models in order to apply and check the theoretical findings and finally reach conclusions on the development of Zero energy buildings in hot climate countries. During the building simulation a variety of parameters such as the weather, the orientation, the shading methods, the insulation methods, the buildings materials, the glazing, the HVAC systems and building operation profiles were checked in order to find the appropriate combination of factors and achieve the zero energy building goals. Conclusions: This new approach to zero energy building, gives a new perspective to the energy consumption of the building and the indoor environment while also taking environmental impact from the building sector into account. This change in approach is a crucial part of the overall problem of how to achieve the ultimate goal of Zero Energy Buildings and how to convert buildings into “producers” of energy and help solve the world energy problem/crisis.
73

Etude des performances du télescope gamma Fermi à basse énergie et impact sur la science / Optimisation of FERMI space telescope performences

Desgardin, Thibaut 25 November 2015 (has links)
Le satellite Fermi, lancé en juin 2008 par la NASA, observe le ciel dans le domaine des hautes énergies. Son instrument principal: le Large Area Telescope (LAT), récolte des données à partir de ~20 MeV jusqu'à plus de 300 GeV. Une amélioration majeure de ses algorithmes à permis récemment la mise à disposition d'un nouveau jeu de données, Pass 8. Pass 8 jette un nouvel éclairage sur le domaine méconnu de la basse énergie (E<100 MeV). En effet à basse énergie, la résolution en énergie et la résolution angulaire du LAT rendent l'analyse de données ardue.Au cours de ce travail de thèse, nous avons proposé une nouvelle paramétrisation capable de décrire la réponse en énergie du LAT sur 6 ordres de grandeur.Fort de ce travail technique et des améliorations apportées par Pass 8, nous nous sommes ensuite attelés à l'analyse des données à basse énergie. Pour cela nous avons extrapolé les modèles d'émission diffuse produits par la collaboration et nous les avons ajustés aux données. Nous avons également étudié 39 sources parmi les plus brillantes du ciel gamma. Les résultats de cette analyse de sources sont présentés dans cette thèse avec un accent particulier mis sur deux des plus brillantes sources du ciel gamma: le pulsar Vela et le pulsar du Crabe ainsi que sa nébuleuse. / Launched in June 2008 by NASA, the Fermi satellite observes the gamma-ray sky. Its main instrument, the LAT, harvests data from ~20 MeV to 300 GeV and beyond.Lately, a major upgrade of the LAT algorithms allowed the release of a reprocessed data set called Pass 8. Pass 8 sheds a new light on the low energy (E<100 MeV) regime where data analysis is difficult due to degraded angular and energy resolution.During this Phd a new parameterization was found for the energy dispersion which allowed an accurate modelisation of the LAT energy response on 6 orders of magnitude.This work, together with other Pass 8 improvements, allows us to consider low energy analysis. To do so, we extrapolated the existing diffuse models to low energy and fitted them to data together with 39 of the brightest low energy gamma-ray sources. The results of this analysis are presented in this manuscript with a particular enphasis on the Vela pulsar and the Crab pulsar plus nebula.
74

Hotel Nábřeží u Kunovské přehrady / Hotel Nábřeží at Kunov dam

Dananaiová, Ladislava January 2020 (has links)
In this diploma thesis is designed a hotel with a restaurant in the recreational areaKunov,close to Senica town. It has a capacity for 50 guests. The smallest rooms are double bedrooms with at least 16 m2anda bathroom 4m2. It is four stars hotel. There are three over ground floors and a basement. On the ground floor there is a reception, toilets, a restaurant for 65 guests. There is also a kitchen and storerooms. There are 5 hotel rooms on the first floor and an office. On the second and third floors there are hotel rooms, common room, cleaning room and laundry room. On the second and third floor there is one wheelchair accessibleroom. In the basement there are utility rooms, storerooms, a workshop, a gym with locker rooms and showers. The main entrance to the building is wheelchair accessible and leads to the reception. There is also a staff entrance from the back of the building and an entrance to the garden with a hotel pool. The roof is designed as a single layer flat roof. On the grounds there are designed outside showers, toilets for men and women and a garden shelter.
75

Návrh řešení komunikačního rozhraní ve WBAN systémech / Design of communication interface in WBAN systems

Kandera, Tomáš January 2020 (has links)
Táto diplomová práca sa zaoberá technickou realizáciou WBAN zariadenia, ktoré je schopné súbežne komunikovať prostredníctvom dvoch bezdrôtových komunikačných protokolov. Rešerš dostupných riešení je dostupná s hodnotením jednotlivých produktov podľa vopred stanovených kritérií. Návrh z hľadiska software obsahuje tvorbu vlastného BLE servisu, konfiguráciu Timeslot API a periférií často využívaných vo WBAN zariadeniach. Výroba dosiek plošných spojov pre zariadenie a dedikovaný ovládač zahŕňa vlastnú anténu, nabíjací obvod batérie a nRF52810 čip. Testovanie prototypov je zhrnuté v poslednej kapitole spoločne s experimentálnym meraním útlmu živočíšneho tkaniva.
76

Wireless Control of Industrial Robot

Paulsson, Johan January 2020 (has links)
The purpose of this project was to investigate if it is possible to have local wireless control of an industrial robot. This was achieved by first doing a diversity of research. Based on the research, the project was conceptualized and a real-life product was developed showcasing the functionality. The standard robot set up as of today consists of three main parts: A robot, a control unit and a handheld controller device, called Teach Pendant. All of these parts are connected with long aggravating cables. The cables cause inconvenience and can in some cases introduce unnecessary risks in the factory. Can this hardware be removed, and an overall more convenient use case be developed? The product was developed by programming an application on a Windows tablet. Further, a Bluetooth Low Energy server was created to handle the communication between the tablet and the robot control unit. The final product consisted of a tablet, a single-board computer, a robot and a control unit. The tablet is what replaces the Teach Pendant as a handheld device. The tablet is connected to the singleboard computer via Bluetooth. The single-board computer acts as a Bluetooth server and sends out advertisements for the tablet to detect. When the tablet detects a nearby robot it can then connect to it and send start and stop commands. The server then forwards it to the control unit which finally sends the data to the robot control unit to execute. The project shows that it is possible to develop wireless robot control. It showcases a potential solution on how one could set it up. However, the final product developed had a simple functionality compared to the wired Teach Pendant. To manage the same capacity as the wired Teach Pendent, further development is required.
77

Investigation on the energy consumption of wireless RPM sensor

Song, Yang January 2020 (has links)
Energy-saving wireless sensors are increasingly used in the industry. Users can remotely monitor the status of the measured device and do not need to frequently replace the battery of the device. In this thesis, we studied a low-cost energy-independent wireless speed sensor system that can power itself by the rotation of the host. The BMG250 MEMS gyroscope is responsible for temperature and angular velocity measurement, and the nRF52832 SoC sends data to the remote monitoring terminal through BLE communication. This study aims to discover the energy consumption and energy saving methods of the entire process of data collection, data transfer, and data transmission. Finally, in order to meet the various test requirements, an energy consumption standard will be summed up to calculate the energy consumption of the entire system.
78

Molecular Dynamics Study of Hydrogen Trapping and Helium Clustering in Tungsten

Gurung, Ashok 28 August 2018 (has links)
No description available.
79

The use of Bluetooth Low Energy Technology for Cost-Effective Construction Equipment Tracking

Mukhtar, Muhammad Hamza 23 August 2022 (has links)
No description available.
80

Detection of Low Energy Particles

Harvey, Stanley B. January 1976 (has links)
Part A of two Project Reports: The other part is designated Part B: Industrial Project / <p>The channel electron multiplier is a radiation detector suitable for the detection of 0.1-100 keV electrons and atomic particles. Studies were made to determine channeltron absolute efficiency as a function of input particle rate, time, and incident energy. The efficiency for electrons was found to vary from 90% for 1 keV electrons to 50% for 4 keV electrons. The channeltron efficiency was found to depend strongly on input rate below 50 counts per second. Although the cause of this discrepency is unclear, a possible explanation was developed involving the secondary emission coefficient of the detector multiplying surface. The channeltron was subsequently used to detect secondary electrons from gold foil bombarded with both electrons and protons. By scattering the incident. particles from a gold foil, the number of secondary electrons generated was found to vary linearly with energy from 2 to 11 keV. The possibility exists for use of the foil-channeltron detector to count neutral atomic particles with known efficiency. This has been a difficult problem in the past. </p> / Thesis / Master of Engineering (MEngr)

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