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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.
1

Effects of turbulence on the ventilation rates through building openings

Frank, Daria January 2016 (has links)
No description available.
2

Methodology for the Performance Evaluation of Ceiling Recessions for Vertical Floor Opening Protection

Grant, Steven January 2013 (has links)
Current Canadian Building Codes mandate prescribed design requirements for the protection of vertical floor openings by means of draft stops and closely spaced sprinklers. In the event that a design cannot meet the requirements, they also allow for the use of an alternative solution as long as the alternative solution can be proven to provide at least an equivalent level of performance as that prescribed in the Code. A commonly suggested alternative to the use of draft stops includes the construction of a recession at the perimeter of the floor opening; however, the performance of this design relative to that of an equivalent draft stop design has not been thoroughly evaluated. In this research, the available methods for the evaluation of ceiling recession designs are reviewed in order to identify appropriate tools with which to conduct such an analysis. While both analytical analysis and experimental testing could be used, experimental testing of the design is not considered here as this option would not commonly be pursued by design teams due to restrictions on both project budget and design timelines. From the available analytical tools, the fire modeling software Fire Dynamics Simulator (FDS) is selected for evaluation of the ceiling recession design due primarily to the ability of FDS to address complex geometries with appropriate spatial resolution to investigate details of flow and thermal profiles at the ceiling level in a larger compartment. Previous FDS studies are reviewed and an independent validation study is conducted in order to develop an analysis methodology which is appropriate for the evaluation of ceiling recession designs. A case study evaluation is conducted consisting of two dimensionally distinct ceiling recession configurations in the same compartment and two separate source fire heat release rates (HRR). Results are analyzed to evaluate the selected analysis methodology with respect to the characteristics of the simulated flow, and thermal detector response. Results show that the presence of an obstruction to the ceiling jet flow significantly improves thermal detector response where the source fire HRR is low. At higher source fire HRRs, the difference in activation time is found to be minimal amongst configurations of ceiling recession considered in the study. Predictions of thermal detector response time for a selected ceiling recession design are compared to predictions made for code-prescribed draft stop configuration as would be necessary for an alternative solution evaluation. Results indicate that ceiling recession designs provide a reduced level of performance at both low and high source fire HRRs when the thermal detector is placed at the recession ceiling level. In contrast, when the thermal detectors are located at distances greater than 80 mm below the upper ceiling, a design which is permitted by the Code, the performance of the ceiling recession appears better than that of the prescribed draft stop design. Results from the model for detectors placed at distances from the ceiling exceeding 40 mm, however, require further confirmation through experimental testing or additional modeling.
3

Methodology for the Performance Evaluation of Ceiling Recessions for Vertical Floor Opening Protection

Grant, Steven January 2013 (has links)
Current Canadian Building Codes mandate prescribed design requirements for the protection of vertical floor openings by means of draft stops and closely spaced sprinklers. In the event that a design cannot meet the requirements, they also allow for the use of an alternative solution as long as the alternative solution can be proven to provide at least an equivalent level of performance as that prescribed in the Code. A commonly suggested alternative to the use of draft stops includes the construction of a recession at the perimeter of the floor opening; however, the performance of this design relative to that of an equivalent draft stop design has not been thoroughly evaluated. In this research, the available methods for the evaluation of ceiling recession designs are reviewed in order to identify appropriate tools with which to conduct such an analysis. While both analytical analysis and experimental testing could be used, experimental testing of the design is not considered here as this option would not commonly be pursued by design teams due to restrictions on both project budget and design timelines. From the available analytical tools, the fire modeling software Fire Dynamics Simulator (FDS) is selected for evaluation of the ceiling recession design due primarily to the ability of FDS to address complex geometries with appropriate spatial resolution to investigate details of flow and thermal profiles at the ceiling level in a larger compartment. Previous FDS studies are reviewed and an independent validation study is conducted in order to develop an analysis methodology which is appropriate for the evaluation of ceiling recession designs. A case study evaluation is conducted consisting of two dimensionally distinct ceiling recession configurations in the same compartment and two separate source fire heat release rates (HRR). Results are analyzed to evaluate the selected analysis methodology with respect to the characteristics of the simulated flow, and thermal detector response. Results show that the presence of an obstruction to the ceiling jet flow significantly improves thermal detector response where the source fire HRR is low. At higher source fire HRRs, the difference in activation time is found to be minimal amongst configurations of ceiling recession considered in the study. Predictions of thermal detector response time for a selected ceiling recession design are compared to predictions made for code-prescribed draft stop configuration as would be necessary for an alternative solution evaluation. Results indicate that ceiling recession designs provide a reduced level of performance at both low and high source fire HRRs when the thermal detector is placed at the recession ceiling level. In contrast, when the thermal detectors are located at distances greater than 80 mm below the upper ceiling, a design which is permitted by the Code, the performance of the ceiling recession appears better than that of the prescribed draft stop design. Results from the model for detectors placed at distances from the ceiling exceeding 40 mm, however, require further confirmation through experimental testing or additional modeling.
4

Spridning av suspenderade ämnen vid grumlande arbeten : Examensarbete på uppdrag av AFRY angående utbyggnad av kajområde i Kallholmsfjärden, Skellefteå

Lundström, Stina January 2020 (has links)
A consequence of stirring sea bottoms within construction sites is that suspended particles are being released. Pollutants such as heavy metals are often bonded to suspended particles which can spread over long distances. Analyzing the levels of particles in the water can either be made in a laboratory, or by measuring turbidity. Turbidity is a measure of the water’s ability to diffuse light and is used to determine the content of suspended material. This thesis is made in collaboration with AFRY who is preforming water sampling during a construction of a new quay area in Kallholmsfjärden, Skellefteå. The purpose of this study has been to investigate if, and how, suspended substances are being spread during water-based constructions that causes stirring of the sea bottom. The study was carried out by analyzing data sampled from Kallholmsfjärden. In summary, the result indicate that water-based constructions may result in suspended substances being spread into the water. Suspended material is correlating with turbidity, which means that turbidity can be used as an indicator for suspended materials. The kind of operation preformed during construction, affects the turbidity and dredging leads to higher particle scattering than padding. The result underlines the importance of taking preventive measures that reduce particle scattering, and one way of doing that is by using silt curtains. According to the result, silt curtains fulfill its purpose by preventing particle scattering. Finally, there is no difference in suspended material between dissimilar depths. The result of this theses is relevant when planning similar projects.
5

Energy Saving Curtain : ENERGY INVENTORY AND CONSERVATION POSSIBILITIES

Zou, Fan January 2008 (has links)
<p>This paper presents the energy saving curtains, in order to make the</p><p>consumers be more aware of the energy efficiency of the energy saving</p><p>curtains, the paper gave related analysis and conclusions.</p><p>The work was performed by using the Parasol Program, developed by Lunds University, Sweden. The Program is used for quantifying the influence of window size, glass type, textile type, wall thermal insulation and sun shading on annual energy use and indoor thermal comfort. The results which are obtained from the calculations are applicable to similar climatic and environment conditions. Calculations were performed to investigate the potential for using sunshade devices to reduce annual energy demand for cooling and heating. Different materials and dimensions of the energy saving</p><p>curtain are used as variables in the analysis. The results indicated that for the current climatic conditions and other related factors, the total reduction rate of the annual energy consumption of office used buildings in Stockholm is estimated generally 20% -30% lower comparing to those buildings without energy saving curtain system. That means at least 20% of energy cost can be saved by the energy saving curtain system.</p>
6

Energy Saving Curtain : ENERGY INVENTORY AND CONSERVATION POSSIBILITIES

Zou, Fan January 2008 (has links)
This paper presents the energy saving curtains, in order to make the consumers be more aware of the energy efficiency of the energy saving curtains, the paper gave related analysis and conclusions. The work was performed by using the Parasol Program, developed by Lunds University, Sweden. The Program is used for quantifying the influence of window size, glass type, textile type, wall thermal insulation and sun shading on annual energy use and indoor thermal comfort. The results which are obtained from the calculations are applicable to similar climatic and environment conditions. Calculations were performed to investigate the potential for using sunshade devices to reduce annual energy demand for cooling and heating. Different materials and dimensions of the energy saving curtain are used as variables in the analysis. The results indicated that for the current climatic conditions and other related factors, the total reduction rate of the annual energy consumption of office used buildings in Stockholm is estimated generally 20% -30% lower comparing to those buildings without energy saving curtain system. That means at least 20% of energy cost can be saved by the energy saving curtain system.
7

ESTUDO DE CORTINAS BLACK-OUT COMO COMPONENTES NO ISOLAMENTO SONORO DE FACHADAS / A STUDY OF BLACKOUT CURTAINS AS COMPONENTS IN SOUND ISOLATION FACADES

Pisani, Angela Paulina Grandeaux 24 October 2008 (has links)
Buildings which have high levels of sound pollution and facades that do not isolate outside noise are often found in large cities. This situation affects people s sound comfort and health. In connection with that, there is the high cost of materials which offer good sound reduction indices. This way, it is necessary to investigate alternative materials at lower costs, such as the blackout curtains. Taking these factors into consideration, the aim of this study is to examine the increase of sound isolation index (Rw) in relation to outside noise, through the use of vynil and polyester curtains in windows. The tests were carried out at the Acoustic Laboratory of the Federal University of Santa Maria. The results of the tests have shown the performance of various curtains arrangements, resulting in a 2 to 5 dB increase in the sound isolation index. Duplicating curtains enabled an increase of about 1 dB in relation to simple curtains. There was no increase in the sound isolation index when overlapping the curtains. Putting up glass wool panels of different thickness has not influenced in the facade sound isolation. With this study, it has been possible to quantify the improvement of facades sound isolation by putting up blackout curtains currently in the market. / Nas grandes cidades, encontram-se freqüentemente edifícios submetidos a elevados níveis de poluição sonora, cujas fachadas não isolam adequadamente o ruído externo, situação esta que traz conseqüências para o conforto sonoro e para a saúde dos indivíduos. Associado a isto, está o alto custo dos materiais que apresentam bons índices de redução sonora, havendo a necessidade de se estudarem materiais alternativos, com custos menos elevados, como é o caso das cortinas black-out. Levando-se em conta estes fatores, o objetivo deste trabalho é averiguar o acréscimo no índice de isolamento sonoro a ruídos externos, gerado pela colocação de cortinas de vinil e de poliéster, sobrepostas a um elemento de fachada. Os ensaios foram realizados no laboratório do Setor de Acústica da Universidade Federal de Santa Maria. A partir dos resultados dos ensaios verificou-se o desempenho de várias composições de cortinas, obtendo-se um aumento de 2 à 5 dB no índice de isolamento sonoro. A duplicação das cortinas possibilitou um aumento em torno de 1 dB, em relação às cortinas simples. Não houve alteração no índice de isolamento sonoro com o transpasse das cortinas. A colocação de painéis de lã de vidro de diferentes espessuras pouco influenciou no isolamento sonoro da fachada. A partir deste trabalho, pôde-se quantificar qual a melhoria no isolamento sonoro das fachadas propiciada pela colocação de cortinas black-out à disposição no mercado.
8

Etude expérimentale et numérique des rideaux d'eau pour la protection contre le rayonnement thermique / Experimental and numerical study of water curtains used as radiative shields

Lechêne, Sullivan 13 July 2010 (has links)
Les rideaux d'eau sont des milieux semi-transparents constitués de gouttelettes d'eau dispersées dans l'air. Le but de ces rideaux ici n’est pas d’interagir avec la flamme dans une optique d’extinction mais plutôt d’agir en tant que boucliers radiatifs contre une forte source de chaleur. En effet, placés entre une source radiative et une cible à protéger, ils permettent de limiter la propagation du rayonnement grâce notamment au caractère absorbant et diffusant des gouttelettes d’eau. L’intérêt du brouillard d’eau réside dans la présence de fines gouttelettes d'eau. Elles possèdent, à quantité d'eau égale, une capacité d'atténuation du rayonnement largement supérieure à celle des techniques de « sprinklage », utilisant une quantité d’eau abondante constituée de gouttes de gros diamètres. Nous avons travaillé expérimentalement (réalisation d'un pilote) et numériquement (code BERGAMOTE) sur le rôle des conditions d'injection : pulvérisation descendante, ascendante, impactante, jets mutualisés en rampe (avec des systèmes comprenant une seule rampe ou deux rampes associées), etc... pour quantifier et comprendre les phénomènes mis en jeu. On retiendra en particulier le fort couplage entre la dynamique des brouillards ou rideaux d'eau et leur propriété d'écran thermique. Il résulte également de ces travaux qu’une modification de la direction d’injection, tout en conservant la même quantité d’eau injectée, engendre de fortes variations sur la capacité d’atténuation du rideau, s’expliquant par la dynamique des sprays injectés. La taille et la concentration en gouttelettes d’eau (liée au temps de séjour des gouttes dans le domaine) apparaissent alors comme des paramètres cruciaux dans l’optique d’une optimisation de ces systèmes de protection / Water sprays, water curtains, or mists, are semi-transparent media made of droplets dispersed in air. Here, water sprays are not used for the extinction of the flame but for radiative shielding against infrared radiation coming from a hot surface. Indeed, placed between a radiative source and a target to be protected, they are able to limit the radiation propagation, due in particular to the ability of droplets to absorb and to scatter infrared radiation.The advantage of mists consists in the presence of fine water droplets. In fact, with the same water volume, they have a widely superior capacity of attenuation radiation compared to “sprinkler” systems which use much water involved as large droplets. A study has been carried out both experimentally (design of an experimental setup) and numerically (BERGAMOTE code) in order to better understand the role of injection conditions. Therefore downward pulverization, upward pulverization, “impinging” spray, several nozzles in a ramp (with systems including one ramp or two ramps), etc… were investigated in order to quantify and assess the implicated phenomena. In particular, a strong coupling appears between the dynamics of sprays and their property of thermal shield. It was also observed from these works that a modification of injection direction, while conserving the same quantity of injected water, results in a strong variation on the attenuation capacity of water curtain, explained by the dynamics of injected sprays. It is worth noting that diameter and concentration of water droplets (related to the residence time of droplets in the domain) are crucial parameters when optimizing these protection systems
9

Adoptable Space

Wenzel, Andreas 29 December 2004 (has links)
This project investigates an idea of adoptable space as opposed to adaptable space of generic flexibility. An Experimental Performing Arts Center on a site in Downtown Chattanooga is used as a vehicle to define the nature of space, which offers itself for an architectural adoption. Simple elements like platforms, walls, doors, windows and curtains are interpreted in a new way and can be used experimentally to let a theater play happen. / Master of Architecture
10

Experimentell parameterstudie av bubbelridåer i syfte att avleda fisk / Experimental parametric study of bubble curtains for fish-guiding purposes

Wendin, Gustav January 2019 (has links)
Bubble curtains offer a potential solution for hindering downstream migrating fish from passing through the turbines of hydropower plants, by instead guiding them to a safe passage. Compared to the conventional method of using low-inclined bar racks close to the turbine intake, bubble curtains are considerably cheaper, especially for large scale hydropower plants. In this work bubble curtains are evaluated through an experimental parametric study, mainly regarding two quantities, defined here as the overall bubble coverage of the background, as well as the occurrence of large tears in the curtain. The examined parameters cover the design of the device that generates the bubbles, the positioning of the device, as well as the flow condition of the water. The bubble curtain was filmed with underwater cameras and image analysis was performed using image segmentation in MATLAB. Results indicate that the total air flow should be chosen high, around 200-500 nl/min/m. The number of holes the air is distributed across is of little importance, except in the area closest to the air outlets, where permanent tears may occur inbetween holes if the distance is to great. Smaller holes (&lt;1mm) are preferable to larger holes (&gt;1 mm), but the difference is small compared to the effect of the total air flow. In flowing water, a smaller angle of attack against the current is better based on the defined quantities, but it will also result in a longer and therefore more expensive device. The bubble curtain should not be placed where mean water velocities exceed 0,75 m/s, since it will result in an inclination with the current close to that of bar racks designed to guide fish towards the surface. Furthermore, at these water velocities some fish may have difficulties following the curtain, due to their limited swimming capabilities.

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