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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.
31

Windows of Opportunities : The Glazed Area and its Impact on the Energy Balance of Buildings

Persson, Mari-Louise January 2006 (has links)
The impact of window area on the energy balance of a building was investigated by simulations in DEROB-LTH. The glazed area was varied in three types of buildings with different types of glazing and for several climates. One low energy house was compared to a less insulated house but identical in size and layout. Three different types of glazing were used; uncoated double glazing, double glazing with one low-e coated pane and triple glazing with two low-e coated panes. Climates with variations in solar radiation, mean temperature, altitude and latitude were chosen. The results show that if energy efficient window alternatives are chosen the flexibility of choosing the glazed area and orientation is higher. Choosing a larger area facing south resulted in a higher heating demand for uncoated double glazing in the standard house. An increased area also resulted in an increased peak load for heating for all the simulated cases. Choosing the energy efficient glazing type gave a decrease in heating demand for increased south facing glazed area in the standard house. In the low energy house the difference in heating demand between different areas was smaller than for the standard house. An office module with two types of switchable glazing and one solar control glazing unit was used in three different climates; Stockholm, Brussels and Rome. Larger window areas increase the cooling demand but if glazing types with lower solar transmittance are used, the difference in cooling demand between different window areas decreases. An extremely large window area, however, increases the peak load both for cooling and for heating and should therefore be avoided. Energy can be saved by using switchable windows instead of solar control or in particular standard glazing.
32

Är saltglaseringsindustrin en källa till tidig organokloridförekomst?

Liljeroos, Tom January 2009 (has links)
Abstract. The levels of dioxin and comparable substances rose to a large extent in our environment during the second half of the 20'Th century. This was the result of the synthesis of, and careless usage of these substances in cooling fluids, hydraulics, pesticides etc. Background levels of dioxins and furans in sealed samples prior to this era suggest that former sources of these substances existed. Salt glazing is a method of adding a smooth acid resistant exterior to stoneware ceramics. The technique has been in use since the 16'Th century, maybe even earlier than that. Some sources date the origin of the technique to the 13'Th century. Salt glazed ceramics were the prime type of industrial vessels and it was extensively used for food preservation in households from the 17'Th century to the early/mid 20'Th century. The method was/is primarily used by Germany, Great Britain, America and Sweden. Salt glazing is a source of graphite structures from soot, and of chlorine gas. Hence, the formation of organochlorides should be able to occur. The reports main objective is to highlight the question; “Could the salt glazing industry be one of the sources to early dioxin emissions?” Secondary objectives are to present an introduction to dioxin and comparable substances, methods of analysis and symptoms of exposure. The salt glazing industry is much likely one of the anthropogenic sources of early PCDD/F emissions. Though emission levels seem to be quite low, due to the persistence of PCDD/F noticeable levels could have accumulated. When the Leblanc soda process (a known source of PCDD/F) was introduced in 1791, the salt glazing process had already been used for nearly three hundred years.
33

Analysis of Life Cycle Costs and Energy Savings of Electrochromic Glazing for an Office Building

January 2012 (has links)
abstract: Building Envelope includes walls, roofs and openings, which react to the outdoor environmental condition. Today, with the increasing use of glass in building envelope, the energy usage of the buildings is increasing, especially in the offices and commercial buildings. Use of right glass type and control triggers helps to optimize the energy use, by tradeoff between optical and thermal properties. The part of the research looks at the different control triggers and its range that governs the use of electrochromic glass to regulate the energy usage in building. All different control trigger that can be possibly used for regulating the clear and tint state of glass were analyzed with most appropriate range. Its range was triggered such that 80% time of the glass is trigger between the ranges. The other building parameters like window wall ratio and orientations were also investigated. The other half of the research study looks into the feasibility of using the Electrochromic windows, as it is ought to be the main factor governing the market usage of Electrochromic windows and to investigate the possible ways to make it feasible. Different LCC parameters were studied to make it market feasible product. This study shows that installing this technology with most appropriate trigger range can reduce annual building energy consumption from 6-8% but still cost of the technology is 3 times the ASHRAE glass, which results in 70-90 years of payback. This study concludes that south orientation saves up to 3-5% of energy and 4-6% of cooling tons while north orientation gives negligible saving using EC glass. LCC parameters show that there is relative change in increasing the net saving for different parameters but none except 50% of the present glass cost is the possible option where significant change is observed. / Dissertation/Thesis / M.S.D. Architecture 2012
34

Quantificação do percentual de glaciamentono camarão branco do pacífico(Litopenaeus vannamei) congelado: uma nova metodologia / Measurement of glazing percentage in frozen pacific white shrimp (Litopenaeus vannamei) - a new methododology

Rebouças, Lucas de Oliveira Soares 27 August 2015 (has links)
Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-08-31T22:37:45Z No. of bitstreams: 1 LucasOSR_DISSERT.pdf: 2617988 bytes, checksum: 74015a9ee8413de24f14987804728470 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-09-06T15:19:40Z (GMT) No. of bitstreams: 1 LucasOSR_DISSERT.pdf: 2617988 bytes, checksum: 74015a9ee8413de24f14987804728470 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-09-06T15:22:42Z (GMT) No. of bitstreams: 1 LucasOSR_DISSERT.pdf: 2617988 bytes, checksum: 74015a9ee8413de24f14987804728470 (MD5) / Made available in DSpace on 2017-09-06T15:22:49Z (GMT). No. of bitstreams: 1 LucasOSR_DISSERT.pdf: 2617988 bytes, checksum: 74015a9ee8413de24f14987804728470 (MD5) Previous issue date: 2015-08-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Due to the high perishability of seafood, one of the main industry concerns is to improve conservation technologies, reaching a final product of good quality. Among the various methods used, it highlights the glazing process after freezing, which provides greater stability and shelf life for the product. On the other hand, some abuses have been reported regarding the water excess in glazed products, characterized as economic fraud. In this context, the aim of this study was toevaluate the effectiveness of official methods to quantify the glazing percentage in frozenwhite Pacific shrimp (Litopenaeus vannamei) samples, with different glazing percentages. Based on the obtained resultsasuggestion ofa new simpler and more efficient methodologyis a goal. Samples of peeled shrimp were subjected to glazing process (15%, 30%, 40%, 50% and 60%). The glazingpercentage was quantified based on methodologies of INMETRO, MAPA, CODEX, AOAC/NIST and through the proposal suggested in thiswork. The official methods were inefficient in quantifying the glazing percentage, especially with regard to samples containing high glazing percentages. The methodology proposed results were closer to the values of the glazing percentage of frozen shrimpsamples, confirming that the methodology can be an alternative to be used by the inspectors, after collaborative study validation of the methodology / Devido à alta perecibilidade do pescado, uma das principais preocupações da indústria é aperfeiçoar as tecnologias de conservação, alcançando um produto final de boa qualidade. Dentre os vários métodos utilizados se destaca o glaciamento após o congelamento, que proporciona maior estabilidade e vida de prateleira ao produto. Em contrapartida alguns abusos têm sido relatados no tocante ao excesso de água nos produtos glaciados, caracterizando-se como fraude econômica. Nesse contexto, o objetivo do presente estudo foi avaliar a eficiência dos métodos oficiais para quantificação do percentual de glaciamento em amostras de camarão branco do pacífico(Litopenaeus vannamei)congelado, com base nos resultados obtidos sugerir uma nova metodologia simples e mais eficiente.Amostras de camarão descascado foram submetidas a processo de glaciamento (15%, 30%, 40%, 50%, e 60%).O percentual de glaciamento foi quantificado com base nas metodologias do INMETRO, MAPA, CODEX, AOAC/NIST e através da proposta sugerida no trabalho.As metodologias oficiais foram ineficientes na quantificação do percentual de glaciamento, principalmente no que tange às amostras contendo altos percentuais de glaciamento. Os resultados da metodologia proposta se aproximaram mais aos valores do percentual de glaciamento das amostras de camarão congelado, confirmando que a metodologia pode ser uma alternativa a ser utilizada pelos órgãos fiscalizadores, após estudo colaborativo de validação da metodologia / 2017-08-31
35

Daylighting applications of micro-textured optical surfaces

Bhatia, Rikki January 2001 (has links)
Daylighting is the use of natural light to replace artificial light. In traditional rooms sunlight will only illuminate the area closest to the window due to the high solar angle. The rear of the room appears gloomy and occupants will use electric lighting even though there is sufficient daylight to illuminate the interior. The first section of this thesis reports on the application of micro-prisms to glazing. Such systems could improve the penetration of the light and reduce the energy bill. Fig 1: (Left): A traditional window. (Right) A window with the top third coated in microprisms. The aim of the work is to develop suitable structures than can be easily and cheaply mass produced using an industrial UV embossing process. Whenever possible the requirements of this process dictate the physical characteristics of the microstructures. The development process includes all the stages from design to full-scale testing of the prototypes in an office. Several different mechanical methods are used to produce prismatic arrays that conform to an initial design calculation. Each sample is evaluated in terms of its physical characteristics, its optical properties and finally its ability to improve illumination within a room. The latter aspect is determined, not only by measurement, but also the subjective assessment of occupants. The second micro-textured surface to be examined is the microlens. Three systems are investigated: - A controlled diffuser incorporating cylindrical lenses to improve the distribution of the daylight. - An afocal pair of lenses to improve the penetration of daylight through beam-steering. - An angular filter to exclude direct sunlight while admitting diffuse light. Most of the research is concerned with the third system. On sunny days windows can cause sufficient glare that occupants will pull the venetian blinds. Not only will this exclude the direct sunlight but also the diffuse daylight, cause darkening of the room and leading to the use of artificial light. The angular filter or 'solar shade' uses microlenses to image the direct sunlight which can then be blocked by circular obturations. The diffuse sunlight is not focused and therefore transmitted so the room is not darkened. The research is based on experimentation with small-scale systems and computer modelling to optimise the system. The results show potential improvements over new 'smart' windows although mechanical tolerances are high.
36

Advanced decorative ceramics techniques for high school students

Kent, Deborah Ann 01 January 1981 (has links)
This thesis deals with the implementation of luster and underglaze ceramic decorating techniques into the secondary ceramic curriculum. The formation and presentation of this unit is based upon historical and contemporary research of lusters and underglazes, as well as the author's own work with the materials. An instructional unit was designed to fulfill three primary objectives. First, to acquaint the student with the basic materials and techniques; second, to introduce the student to the conceptualization of successful imagery; third, to give the student ample opportunity to explore the uses and possibilities of the materials.
37

Integrating Electrochromic Glazing Technology into Conservation-Focused Lighting Design for Museum Collections

Stapleton, Adrian January 2022 (has links)
Museums, art galleries, and historical sites house items of important cultural value. They must provide sufficient lighting to allow for the public viewing of these items, but are also responsible for conservation of them, which requires strict control of the light levels on delicate materials. Windows provide many benefits to building occupants, but for light control, museums restrict the use of daylight. Electrochromic (EC) glazing changes opacity based on electrical charge, so it is possible to vary the amount of daylight admitted through windows. EC glazing can be integrated with museum lighting through a building management system, which can modulate light levels based on a variety of inputs. The Renwick Gallery is used as a case study for the potential application of EC glazing in a museum space. Because of other requirements for the management of environmental conditions, the use of EC glazing will not show a significant reduction in energy consumption. However, the benefits of access to windows, daylight, and views justify its use. EC technology is advancing rapidly. Due to its current limitations and the logistics of application into a historic structure, the Renwick Gallery may best be served by future advancements.
38

Integration of Phase Change Materials in Commercial Buildings for Thermal Regulation and Energy Efficiency

Malekzadeh, Fatemeh January 2015 (has links)
One of prospective procedures of absorbing thermal energy and releasing it during the required time is the application of phase change materials known as PCMs in building envelopes. High thermal energy storage (TES) materials has been a technology that effects the energy efficiency of a building by contributing in using onsite resources and reducing cooling or heating loads. Currently, many TES systems are emerging and contributing in building assemblies, however using an appropriate type of TES in a specific building and climate requires an in-depth knowledge of their properties. This research aims to provide a thorough review of a broad range of thermal energy storage technologies including their potential application in buildings. Subsequently, a comparative study and simulation between a basecase and an optimized model by PCM is thoroughly considered to understand the effect of high thermal storage building's shell on energy efficiency and indoor thermal comfort. Specifically this study proposes that the incorporation of PCM into glazing system as a high thermal capacity system will improve windows thermal performance and thermal capacity to varying climatic conditions. The generated results by eQUEST energy modeling software demonstrates approximately 25% reduction in cooling loads during the summer and 10% reduction in heating loads during the winter for optimized office building by PCM in hot arid climate of Arizona. Besides, using PCM in glazing system will reduce heat gain through the windows by conduction phenomenon. The hourly results indicates the effect of PCM as a thermal energy storage system in building envelopes for building's energy efficiency and thermal regulation. However, several problems need to be tackled before LHTES can reliably and practically be applied. We conclude with some suggestions for future work.
39

Simulação de desempenho energético de tecnologias fotovoltaicas em fachada de edifício no município de São Paulo. / Energy performance simulation of photovoltaic technologies on the building facade in São Paulo.

Nakano, Alvaro 25 May 2017 (has links)
As tecnologias usualmente aplicadas no mercado fotovoltaico mundial são, em sua maioria, voltadas aos painéis rígidos de células de silício cristalino, em função da redução de seus preços proporcionada pela economia de escala. No entanto, a crescente demanda no País de novos domicílios, principalmente de apartamentos, tem exigido soluções mais apropriadas: com menor ocupação de área horizontal e instaladas na fachada dos edifícios. Nesse sentido vão surgindo tecnologias fotovoltaicas como as de filmes finos como soluções mais apropriadas do que as emergentes de terceira geração, pelo fato dessas últimas ainda se encontrarem em fase de maturação técnica com poucas opções de fornecimento no mercado em nível comercial. Portanto, a abordagem desta dissertação se limitou às tecnologias de filmes finos e de vidros fotovoltaicos semi transparentes, além daquela mais usual que é a de silício cristalino. Contudo, o dinamismo do mercado mundial vem estimulando uma evolução no fator de desempenho dessas tecnologias, o que justificou a necessidade de uma revisão bibliográfica. Além disso, a maioria dos projetos fotovoltaicos vem adotando como base os painéis rígidos com células de silício cristalino, sem, no entanto, avaliarem alternativas com a aplicação de outras tecnologias. O que se nota é a falta de conhecimento mais profundo dos projetistas sobre as tecnologias de filmes finos e das melhores opções para sua aplicação em um edifício, no que tange ao seu desempenho e seu comportamento dentro do espectro de frequência. Assim, esta dissertação teve por objetivo contribuir com uma análise de desempenho energético com base em simulações para tomada de decisão técnica sobre as tecnologias mais adequadas de célula fotovoltaica para sistemas a serem instalados em fachadas de edifícios, auxiliadas por uma ferramenta computacional existente no mercado, o PVSYST. A tomada de decisão foi vista pela perspectiva de desempenho na geração de energia elétrica, pela análise comparativa dos resultados de simulações aplicadas na fachada de um edifício hipotético em São Paulo. Os resultados mostraram que as tecnologias baseadas no silício cristalino são as mais adequadas nos casos em que o pico de demanda de energia no ano seja no verão, como nos edifícios comerciais. Já os sistemas compostos pelos filmes finos do grupo do seleneto de índio e cobre são os mais indicados para os edifícios residenciais, em que o período de maior demanda é no inverno. / Technologies commonly applied in the global photovoltaic market are mostly with the rigid panels of crystalline silicon cells, due to the reduction of their prices provided by economies of scale. However, growing demand in the country of new housing units, mainly apartments, has required more appropriated solutions: with lower occupancy of horizontal area and installed on the building\'s facade. In this direction photovoltaic technologies are emerging such as thin films as better solutions than the emerging technologies of third generation, because still they are in technical maturation phase with few options of suppliers in the commercial market. Therefore, the approach of this dissertation was limited to technologies of thin films and semitransparent photovoltaic glazing, in addition to the more usual one that is crystalline silicon. However, the dynamism of the global market has stimulated an evolution in the performance factor of these technologies, which justified the necessity of literature review. Furthermore, most PV projects have been based on the rigid panels with crystalline silicon cells, not considering the alternatives using other technologies. What is noticed is the lack of deeper understanding of the designers about the thin film technologies and the best options for their application in a building, in terms of their performance and their behavior within the frequency spectrum. Thus, this work aimed to contribute to an energy performance analysis based on simulations for technical decision on the most appropriate photovoltaic cell technologies for systems to be installed on the facades of buildings, aided by an existing software tool on the market, PVSYST. Decision making was seen from the perspective of performance in electricity generation, by comparative analysis of simulations results applied on the facade of a hypothetical building in São Paulo. The results showed that the technologies based on crystalline silicon are the most appropriate in cases where energy demand peak in the year is in the summer, as in commercial buildings. On the other hand, the systems composed of the thin films based on indium and copper selenium group are the most suitable for residential buildings, where the period of greatest demand is in the winter.
40

Études expérimentale et numérique des performances énergétiques d'une fenêtre pariétodynamique / Experimental and numerical study of energy performances of an airflow window

Greffet, Rémy 31 March 2016 (has links)
L'utilisation massive des énergies fossiles est en grande partie responsable des émissions de gaz à effet de serre. De plus, la croissance de la demande énergétique et la raréfaction des ressources fossiles conduisent à l'accroissement du coût de l'énergie. La réponse à cette problématique passe par deux moyens d'action indissociables : la réduction des consommations énergétiques et le recours aux énergies renouvelables. La fenêtre pariétodynamique permet d’agir sur les deux postes principaux de déperdition thermique d’un bâtiment que sont les baies et la ventilation. Le principe de la fenêtre pariétodynamique étudiée est de faire circuler de l’air en convection forcée entre trois verres avant d’être restitué à l’ambiance intérieure du bâtiment. Cela permet à l’air de récupérer à la fois une partie des déperditions thermiques à travers la fenêtre et une partie de l’énergie solaire absorbée par les verres. Afin d’étudier le comportement thermo-aéraulique et les performances de la fenêtre, nous avons développé un modèle numérique de cette dernière. Un dispositif expérimental a été mis en place et utilisé afin de valider le modèle numérique et de comparer en conditions réelles les performances de la fenêtre étudiée à celles d’une fenêtre à double vitrage classique. Ces résultats expérimentaux ont été complétés par une étude paramétrique numérique réalisée pour différentes conditions climatiques et de fonctionnement. Les principaux enseignements issus de ces études expérimentales et numériques sont que le préchauffage de l’air se fait essentiellement dans la lame d’air intérieure, la température de la première lame d’air restant proche de celle de l’air extérieur. De plus, et contrairement aux températures de la face intérieure et de l’air soufflé, celle de la face externe de la fenêtre est peu impactée par les paramètres étudiés. Concernant le cadre de la fenêtre, nous avons observé que celui-ci bénéficie aussi des échanges thermiques avec l’air circulant, mais dans une moindre mesure. Cela contribue à rendre la fenêtre peu déperditive. Enfin, en couplant le modèle développé à un logiciel de simulation thermique dynamique, nous avons évalué le potentiel d’intégration de fenêtres pariétodynamiques dans une maison individuelle. Nous mettons ainsi en évidence que le besoin de chauffage est réduit d'environ 20 à 30 % par l’utilisation de fenêtres pariétodynamiques à la place de fenêtres à double vitrage classique. En été, si l’ambiance intérieure du bâtiment est plus fraîche que l’environnement extérieur, la fenêtre pré-rafraîchit l’air neuf entrant. / The massive use of fossil energies is largely responsible for greenhouse gas emissions. Moreover, the growth in energy demand and the depletion of fossil resources lead to an increase in energy costs. The response to this challenge requires two means of action which are linked : the reduction of energy consumption and the use of renewable energy. The airflow window acts on the two main ways of building heat losses that are windows and the ventilation. The principle of the studied airflow window is based on the circulation of fresh air, by forced convection, between the three glasses of the window before entering the building. This allows air to recover both a part of heat losses through the window and part of the solar energy absorbed by the glasses. To study the thermo-aeraulic behavior and thermal performances of the window, we have developed a numerical model of the studied airflow window. An experimental set up was used to validate the numerical model and compare, in real conditions, the studied window performances to the ones of a conventional double-glazed window. These experimental results were complemented by a numerical parametric study for different climatic and operating conditions.The main information from these experimental and numerical studies are that the preheating of the air takes place essentially in the inner air gap, temperature in the first air layer remaining close to the outdoor one. In addition, unlike the temperatures of the inside face and of the blown air, the outer face temperature of the window is not greatly affected by the studied parameters. On the window frame, we found that it also benefits of heat exchanges with the circulating air, but to a lesser extent. This makes the window energy efficient. Finally, by coupling the developed model to a thermal building simulation software, we evaluated the airflow windows integration potential in a house. We thus demonstrated that the heat load is reduced by about 20 to 30% by the use of airflow windows instead of conventional double-glazed windows. Moreover, in summer, when indoor is cooler than outdoor, we pointed out that the airflow window cools the incoming fresh air.

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