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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.
151

The Efficacy of Using a Natural Soil Additive for the Establishment, Survival and Diversity of Native Prairie and Spontaneously Colonizing Plant Communities on Unirrigated Green Roofs in a Humid Subtropical Climate

Lackey, Gordon Mims 09 May 2015 (has links)
Green roofs are an emerging technology promoted primarily for stormwater management but little has been published about their potential for biodiversity performance. This is the first study to explore the potential for creating prairie-like, non-succulent, native plant communities on unirrigated extensive green roofs in the southeastern United States. Ten experimental green roof platforms were used to: 1) identify native species and methods of establishment appropriate for green roof applications in the southeastern United States; 2) examine the effects of introducing natural soil into a commercially available green roof soil media mixture on the survival and establishment of native prairie species; and 3) examine the composition of early successional green roof plant communities. Eleven planted species were successfully established and 46 colonizing species were identified. It was found that the addition of native prairie soil did not significantly affect survival, overall cover, or biodiversity in terms of species richness and evenness.
152

Examining the Relationship between Avifauna and Green Roofs in Mississippi's Humid-Subtropical Climate

Lamb, Sara Katherine 14 August 2015 (has links)
Human settlement displaces and fragments natural habitats. Design choices in the landscape directly affect both local diversity and extinction rates. This study seeks to understand how avifauna are responding to this new technology in Mississippi.
153

Publikum Nynäshamn: Social-ecological Architecture in Public Municipal Space

Ranara, Jeff January 2019 (has links)
Publikum Nynäshamn docks directly to the west façade of the existing 9 story municipal building with seven floors of open activity space. These surround a full-height atrium across which a two-floor living plant green wall provides the monumental living presence of nature and its ecosystem services in an office environment.  Plants also grace the other side of this two story wall, providing a living backdrop for the heart of the building - the raised three floor high assembly hall. A lunchroom with balconies above the assembly hall provides city views and a roof garden for municipal staff. The two floor high lobby beneath the assembly hall provides a new internal city street between Banana Square and Floravägen – a former back alleyway.  A ground-level colonnade walkway with benches surrounds the new and old buildings, inviting citizens into the building spaces. Public space and circulation is further enhanced with a new passageway opening up the former dead-end southwest corner of Banana Square where the old municipal building met Folkets hus (People’s House). A generous stair complex in this new sunny southern square provides spontaneous seating and meeting spaces as well as additional outdoor access to the two floor café, art gallery, and the largest green roof – one of three accessible green roofs that enhance social and ecological values.  Pedestrian movement can continue through this new passageway directly down to Svandammen (swan pond), and in the opposite direction, directly up to Banana square from the commuter rail station.   The café and two-floor meeting room spaces provide evening and weekend public social spaces for the city residents, complementing existing bars and restaurants in the adjoining Folkets Hus.   Reduced use of energy is encouraged with progressively rising central spaces allowing for the possibility of natural stack ventilation, thermal mass energy storage in concrete (HD/F) slabs, and generous natural daylight through the glazed curtain wall climate shell surrounding the building.  Abstracted winged structures crown the top of the building and grace the building entrances, inspired by the sightings of sea eagles reported in this coastal area, and provides both a signum for the building (instead of a more traditional municipal building tower) and extended surface for rainwater collection that can be used for watering indoor green plant walls and the roof garden vegetation.  The deeper soil of the intensive green roofs not only provides more uptake and retention of rainwater (and thus reduced peak flow rates favorable for stormwater management) but also allows planting of larger, woody plants and bushes, and even small trees, which in turn, among other social and ecological benefits, add natural habitat to a predominantly impervious-surfaced downtown urban area.
154

A Comparative Analysis Of Green Roof Designs Including Depth Of Media, Drainage Layer Materials, And Pollution Control Media

Kelly, Matt 01 January 2008 (has links)
Population growth has lead to an increase in development and impervious areas in urban settings. Post-development conditions cause several problems for stormwater management such as limited space for stormwater storage systems and the conveyance of pollution picked up by runoff to near by water bodies. Green Roofs with cisterns have been shown to attenuate the peak flow of storm events and reduce the pollution load leaving a site and entering nearby water bodies. The purpose of this research is to expand the available research data on green roofs with cisterns by investigating the water quality and hydrology effects of different green roof designs including depth of media, an additional pollution control layer beneath the growth media, and different drainage layer materials. Furthermore, a comparison study is performed on the cistern water quality, direct filtrate water quality, and control roof filtrate water quality. Results show that phosphorus concentrations are lower when using a pollution control layer beneath the growing media, and that evapotransporation and filtrate factor values from the 4-inch media and the 8-inch media are approximately equal for one year. However, hydrograph results show that the 8-inch media design has a lower peak flow and longer attenuation when compared to the 4-inch media design for a single storm event. Furthermore, the drainage layer material has no significant effect on the water quality or hydrology of the green roof discharge. The data also emphasizes the importance and effectiveness of the incorporation of a cistern into a green roof system.
155

Role of Plant Species Richness in Green Roof Plots on the Quantity and Quality of Stormwater Runoff

Johnson, Catherine E. 17 October 2014 (has links)
No description available.
156

Strength evaluation of strut-purlins

Hatch, Gerald L. 09 May 2009 (has links)
Diaphragm braced strut-purlins are commonly used in the roof systems of metal buildings. However, the design problem of combined uplift and axial loads on these members is not adequately addressed in the 1989 AISI specification. The objective of this thesis is to provide experimental evidence that strut-purlins can be designed with an existing interaction equation. It was a/so the objective of this thesis to find a method of determining the axial capacity of diaphragm braced strut-purlins and to experimentally verify the accuracy of the method. / Master of Science
157

Selection of a roof frame for a gymnasium

Glover, Helen Ford January 1948 (has links)
This thesis is concerned with the choice of an appropriate roof frame for the gymnasium element of a high school designed by Joseph P. Staniunas as a thesis for the degree of Master of Science in Architecture. The writer is not attempting to consider every possible condition of framing which might be used in this structure. The frame spacing indicated in the original design is accepted without question, because the fifteen foot spacing given is very nearly the condition for maximum economy for conventionally loaded roof slabs of minimum depth. The framing types are limited to the two-hinged and the three-hinged forms as indicated in the original design. Only two materials, structural steel and reinforced concrete, are considered, although it is recognized that laminated wood might also be suitable. In his thesis, Mr. Staniunas expresses a preference for laminated wood arches to span the gymnasium. He feels that "laminated wood arches give a cleaner appearance to the interior." This writer believes his objective may be equally well obtained in steel or concrete. Therefore, the frames will be designed on this basis, selecting from the four, the best from the standpoints of structure, aesthetics, and economy. The computations occupy approximately 200 pages. It is not felt that this material could be successfully compressed for inclusion in this presentation. Instead, the entire body of computations is reproduced on microfilm and the film is on file at the main college library. The writer feels that the three-hinged steel frame is the most desirable of the four for the following reasons, in order of importance: (a) In appearance it is the lightest and airiest of the four frames examined and accords well with the general character of Mr. Staniunas' design. (b) It is one of the least costly of the four frames. (c) It is readily erected with light equipment Which would be an advantage in Blacksburg, where heavy equipment is not easily available. / M.S.
158

Life cycle sustainability assessment of alternative green roofs – A systematic literature review

Tighnavard Balasbaneh, A., Sher, W., Madun, A., Ashour, Ashraf 26 July 2024 (has links)
Yes / There is general agreement on the importance of green roofs as ways of reducing GHG emissions, reducing overall costs and improving sustainability in urban areas. This systematic literature review highlights life cycle sustainability assessment as an essential criterion to evaluate green roofs. A bibliometric analysis was used to quantitatively review relevant literature. The Scopus database was chosen as a bibliographic database of academic publications. Thes period of search started from 2003 and final search was conducted on February 15, 2023. Based on further in-depth reading, 88 publication records which met the selection criteria, including 74 papers and 14 conference papers. Researchers from the United States contributed almost 31 % of the documents. We evaluated leading studies in this field and discussed assessment method, system boundaries and research gaps through a critical literature review and a systematic search review. Finally, we propose a framework and identify a gap and future research. The environmental aspect of green roofs have received more attention than economic issues. We found that most economic evaluations of green roofs are limited to their construction stage. As yet there is no comprehensive social study on green roofs. We considered a unified study of the economic, environmental impact and social evaluation of green roofs to be warranted. Additionally, various measurement methods should be used to assess the economic profitability of green roofs over the long term. In summary, this study provides a deeper understanding of the environmental, social, and economic performance of green roofs and identifies research gaps as well as future research directions. / The full-text of this article will be released for public view at the end of the publisher embargo on 21 Nov 2024.
159

Life cycle sustainability assessment of alternative green roofs – A systematic literature review

Balasbaneh, A.T., Sher, W., Madun, A., Ashour, Ashraf 22 November 2023 (has links)
Yes / There is general agreement on the importance of green roofs as ways of reducing GHG emissions, reducing overall costs and improving sustainability in urban areas. This systematic literature review highlights life cycle sustainability assessment as an essential criterion to evaluate green roofs. A bibliometric analysis was used to quantitatively review relevant literature. The Scopus database was chosen as a bibliographic database of academic publications. Thes period of search started from 2003 and final search was conducted on February 15, 2023. Based on further in-depth reading, 88 publication records which met the selection criteria, including 74 papers and 14 conference papers. Researchers from the United States contributed almost 31 % of the documents. We evaluated leading studies in this field and discussed assessment method, system boundaries and research gaps through a critical literature review and a systematic search review. Finally, we propose a framework and identify a gap and future research. The environmental aspect of green roofs have received more attention than economic issues. We found that most economic evaluations of green roofs are limited to their construction stage. As yet there is no comprehensive social study on green roofs. We considered a unified study of the economic, environmental impact and social evaluation of green roofs to be warranted. Additionally, various measurement methods should be used to assess the economic profitability of green roofs over the long term. In summary, this study provides a deeper understanding of the environmental, social, and economic performance of green roofs and identifies research gaps as well as future research directions. / The full-text of this article will be released for public view at the end of the publisher embargo on 25 Nov 2024.
160

Study of environmental and energy performance of vegetative roofs and assessment of their impacts in terms of rainwater management / Étude des performances environnementales et énergétiques des toitures végétalisées et évaluation de leur impact en termes de gestion de l'eau de pluie

El Bachawati, Makram 11 July 2016 (has links)
Les toitures végétalisées (TTV) existent en deux types : extensive (EGR) et intensive (IGR). Ils diffèrent principalement par le type de végétation et la profondeur du substrat. Ces travaux de recherche visent à atteindre les objectifs suivants : 1. Déterminer et comparer les impacts environnementaux d’un toit de gravier ballasté traditionnel (TGBR), d’une toiture réfléchissante (WRR), EGR, et IGR ; 2. Quantifier la performance énergétique d’un TGBR et d’une EGR ; 3. Évaluer le potentiel de gestion d’eau et la dynamique de ruissellement d’un TGBR et d’une EGR. Le 1er objectif a été atteint suite à une Analyse comparative de Cycle de Vie (ACV) d’une EGR réelle de 834 m2 et de trois toits fictifs : TGBR, WRR, et IGR. Les résultats indiquent qu’une EGR présente les impacts environnementaux les plus bas pour les 15 catégories d'impacts considérées. Les aspects thermiques et hydriques des TTV ont été testés suite à l’installation d'une maquette TGBR et de deux maquettes EGR sur le toit du département de génie chimique à l'Université de Balamand, Liban. EGR8 et EGR16 sont des maquettes EGR qui diffèrent par la pente ainsi que la profondeur et la composition du substrat. Les profils de température indiquent la réduction des fluctuations de température, l'effet de stockage de chaleur, et l'effet de refroidissement passif. L'étude économique montre que EGR pourrait économiser jusqu'à 45USD/200m2/mois par rapport à TGBR. D’autre part, les profils de la teneur en eau ont démontré que la composition du sol d’EGR8 est plus efficace que celle d’EGR16. En revanche, EGR agit comme un système filtrant surtout pour le cadmium, le fer, le calcium et l'ammonium. / Vegetative roofs (VRs) can be classified into two types : Extensive (EGR) and Intensive (IGR). The main differences between the two are the type of vegetation, the depth of the substrate. This research aims to achieve the following objectives : 1. Determine and compare the potential environmental impacts of traditional gravel ballasted roofs (TGBRs), white reflective roofs (WRRs), EGRs, and IGRs ; 2. Evaluate and compare the energy performance and the heating/cooling demand of TGBRs and EGRs ; 3. Determine and compare the water management potential and the runoff dynamics of TGBRs and EGRs. The first objective was covered by performing a comparative Life Cycle Assessment (LCA) on a real EGR of 834m2 and on three fictitious roofs of the sane area : of TGBRs, WRRs, and IGRs. Results indicated that the EGR had the least potential environmental impacts for the 15 impact categories considered. The second and third objectives were achieved by first installing one TGBR mockup and two EGR mockups on the rooftop of the Chemical Engineering Department at the University of Balamand, Lebanon. EGR8 and EGR16 are EGR mockups differed in the roof slope, the depth and the composition of their substrate. Temperature profiles at different substrate depths clearly indicated the reduction of the temperature fluctuations under the substrate layer, the heat storage effect, and the passive cooling effect. The economic study showed that EGR could save up to 45USD/200m2/month compared to TGBR. The water management performance of EGRs illustrated that the soil composition of EGR8 was more efficient than that of EGR16. In contrast, EGR acted as a sink especially for cadmium, iron, calcium, and ammonium.

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