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Thesis (Ph. D.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xvi, 357 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 132-124).

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Air pollution and urban heat island effect caused from the development of infrastructures are getting serious, in which air flow is reduced and heat is trapped among high-rise buildings. In order to mitigate these problems, various methods have been developed in previous studies. Green roof has been identified as one of the most important means to mitigate these problems and implement sustainable development principles in the building features. Governments world-wide have been introducing various policies and regulations for promoting green roof particularly for building projects. However, existing buildings in Hong Kong display limited green roof features, especially for old buildings. Hong Kong is one of the most densely populated cities with many high-rise buildings. This paper examines the major barriers encountered in promoting green roof systems for existing buildings in Hong Kong. A case study approach is adopted to investigate how and why the barriers hindered the implementation of green roof features. Research results showed that lack of promotion and incentives from government and lack of government coordination are the top barriers to the implementation. This research concludes by providing suggestions and actions that can help mitigate these barriers. / published_or_final_version / Housing Management / Master / Master of Housing Management

The objective of this study was to optimize the cultural and environmental conditions necessary to produce high quality basil in a semi-arid climate during summer. Basil grown in a retractable roof greenhouse (RRGH) and full sun over two years using production systems including rockwool, containers, raised beds, vertical towers, and soil was evaluated based on biomass accumulation, morphological characteristics and quality. Photosynthetic response of basil to temperature and light was tested in a growth chamber to determine the optimum conditions that enhance photosynthesis and increase productivity. Biomass accumulation and quality of basil were affected by environment and cultural practices, with the largest quantities of highest quality basil produced in rockwool or raised beds in the RRGH. The response of basil to light and temperature indicated that highest photosynthesis during summer occurred between temperatures of 25 to 35 °C at a light intensity of 1500 μmol m⁻¹ s⁻¹.

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Thesis (Ph. D.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains xvii, 278 p. : ill. (some col.), maps. Vita. Includes abstract. Includes bibliographical references (p. 274-277).

Thesis (MScIng)--University of Stellenbosch, 2008. / Bibliography. Also available via the Internet.

abstract: Unmanned Aerial Vehicles (UAVs) have become readily available for both the average consumer and professional due to decreases in price and increases in technological capabilities. This work ventured to explore the feasible use of UAV-technology in the area of roof analysis for facilities management purposes and contrast it to traditional techniques of inspection. An underlying goal of this work was two-fold. First, it was to calculate the upfront cost of investing in appropriate UAV equipment and training for a typical staff member to become proficient at doing such maintenance work in the practice of actual roof inspections on a sample set of roofs. Secondly, it was to compare the value of using this UAV method of investigation to traditional practices of inspecting roofs manually by personally viewing and walking roofs. The two methods for inspecting roofs were compared using various metrics, including time, cost, value, safety, and other relevant measurables. In addition to the study goals, this research was able to identify specific benefits and hazards for both methods of inspection through empirical trials. These points illustrate the study as Lessons Learned from the experience, which may be of interest to those Facilities Managers who are considering investing resources in UAV training and equipment for industrial purposes. Overall, this study helps to identify the utility of UAV technology in a well-established professional field in a way that has not been previously conducted in academia. / Dissertation/Thesis / Masters Thesis Construction Management 2020

This thesis addresses the problem of designing roof support systems in coal mines. When designing the roof support, it is necessary to account for the uncertainties that are inherently exist within the rock mass and support elements. The performance of a support system is affected by these uncertainties, which are not taken into account in the current design methodologies used in South Africa. This study sets out to develop a method which takes all uncertainties into account and quantitatively provides a risk-based design. Despite the fact that the roof bolting is probably one of the most researched aspects of coal mine ground control, falls of ground still remain the single major cause of fatalities and injuries in South African collieries. Mainly five different support design methodologies have been used; namely, analytical modelling, numerical modelling, physical modelling, design based on geotechnical rating systems and field testing. As part of this study, it is shown that there are many elements of a support system that can impact the support and roof behaviour in a coal mine and the characteristics of these elements as well as the interaction between them is complex and can vary significantly within a short distance. These variations account for uncertainties in coal mine roof support and they are usually not taken into account in the above design methodologies resulting in falls of ground and/or over design of support systems. The roof and support behaviour were monitored at 29 sites at five collieries. It is found that there was no evidence of a dramatic increase in the stable elevations as experienced in some overseas collieries. A roadway widening experiment was carried out to establish the critical roof displacements. The maximum width attained was 12 m at which stage 5 mm displacement was measured. During the monitoring period no roof falls occurred at any of the 29 sites and road widening experiment site, even where 12 mm displacements were measured. The in situ monitoring programme was continued in additional 26 monitoring stations in 13 sites with the aim of establishing the effect of unsupported cut-out distance on roof and support performances. The results showed that the lithological composition of the roof strata plays a major role in the amount of deflection that was recorded. Bedding separation was seen to occur at the contacts between different strata types. It is concluded that the roof behaved like a set of composite beams with different characteristics. It is also found that the amounts of deflection corresponded with the deflection that would be expected from gravity loaded beams. During this monitoring programme variable nature of roof and support systems are also demonstrated. As many mines use different geotechnical rating systems, an evaluation of the currently used classification techniques were conducted to determine their effectiveness in design of roof support strategies. It is found that currently used systems cannot quantitatively determine the required support system in a given geotechnical environment. Impact splitting tests are found to be the appropriate system for South African conditions. It is however concluded that the roof lithology, stress regime and roof characteristics can change within meters in a production section. Therefore, in order to predict these changing conditions many boreholes are required for a section, which would be costly and time consuming. An in-depth study into the roof support elements was conducted for the purpose of obtaining an understanding of the fundamental mechanisms of roof support systems and developing guidelines for their improvement. All of the currently available roof bolt support elements and related machinery were evaluated using in situ short encapsulated pull tests. The results showed that, on average, bond strengths obtained from the roof bolts supplied by different manufacturers can vary as much as 28 per cent. The test results conducted on different resins showed that the strength of resin currently being used in South Africa is adequate. Differences between commonly used bit types were established. It is concluded that the 2-prong bit outperforms the spade bit in sandstone and shale rock types. In addition, the effect of hole annulus was also investigated as part of this study. The results show that an annulus between 2.5 mm to 3.8 mm resulted in the most effective bond strengths. The effect of wet and dry drilling was noted. It is found that bond strengths and overall support stiffnesses are greater with the use of the wet drilling in all resin types. The results from the tests in different rock types highlighted the very distinct differences between bolt system performances. Quality control procedures for compliance with the design, support elements and quality of installation are presented. Recommendations for improving the quality control measures and for developing testing procedures for bolt system components, installation quality and resin performance are provided. Finally, a roof support design methodology that takes into account all natural variations exist within the rock mass and the mining process has been developed and presented. This was achieved by adapting a probabilistic design approach using the well established stochastic modelling technique. This methodology enables rock engineers to design roof support systems with greater confidence and should result in safer and economic extraction of coal reserves. / Thesis (PhD)--University of Pretoria, 2008. / Mining Engineering / unrestricted