WorldWideScience

Sample records for aboveground roofed design

  1. Aboveground roofed design for the disposal of low-level radioactive waste in Maine

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, J.A. [Univ. of Maine, Orono, ME (United States)

    1993-03-01

    The conceptual designs proposed in this report resulted from a study for the Maine Low-level Radioactive Waste Authority to develop conceptual designs for a safe and reliable disposal facility for Maine`s low-level radioactive waste (LLW). Freezing temperatures, heavy rainfall, high groundwater tables, and very complex and shallow glaciated soils found in Maine place severe constraints on the design. The fundamental idea behind the study was to consider Maine`s climatic and geological conditions at the beginning of conceptual design rather than starting with a design for another location and adapting it for Maine`s conditions. The conceptual designs recommended are entirely above ground and consist of an inner vault designed to provide shielding and protection against inadvertent intrusion and an outer building to protect the inner vault from water. The air dry conditions within the outer building should lead to almost indefinite service life for the concrete inner vault and the waste containers. This concept differs sharply from the usual aboveground vault in its reliance on at least two independent, but more or less conventional, roofing systems for primary and secondary protection against leakage of radioisotopes from the facility. Features include disposal of waste in air dry environment, waste loading and visual inspection by remote-controlled overhead cranes, and reliance on engineered soils for tertiary protection against release of radioactive materials.

  2. Collaborative active roof design

    NARCIS (Netherlands)

    Quanjel, E.M.C.J.

    2008-01-01

    Roofs play an essential role in buildings. Their value and impact often significantly surpass the cost ratio they represent in the total investment cost of the building. Traditionally, roofs have a protecting function and their basic design has changed little over hundreds of years. Nowadays

  3. Leaf Roofdesigning luminescent solar concentrating PV roof tiles

    NARCIS (Netherlands)

    Reinders, A.H.M.E.; Doudart de la Grée, G.C.H.; Papadopoulos, A.; Rosemann, A.L.P.; Debije, M.G.; Cox, M.G.D.M.; Krumer, Z.

    2016-01-01

    The Leaf Roof project on the design features of PV roof tiles using Luminescent Solar Concentrator (LSC) technology has resulted in a functional prototype . The results are presented in the context of industrial product design with a focus on the aesthetic aspects of LSCs. This paper outlines the

  4. Leaf Roof - Designing Luminescent Solar Concentrating PV Roof Tiles

    NARCIS (Netherlands)

    Reinders, Angelina H.M.E.; Doudart de la Gree, G.; Papadopoulos, A..; Rosemann, A.; Debije, M.G.; Cox, M.; Krumer, Zachar

    2016-01-01

    The Leaf Roof project on the design features of PV roof tiles using Luminescent Solar Concentrator (LSC) technology [1] has resulted in a functional prototype. The results are presented in the context of industrial product design with a focus on the aesthetic aspects of LSCs [2]. This paper outlines

  5. Six aspects to inspirational green roof design

    Energy Technology Data Exchange (ETDEWEB)

    Kiers, H. [SWA Group, Sausalito, CA (United States)

    2004-07-01

    Green roofs have been categorized as a technology that is not initially faster, better or cheaper, and may even under perform established products. However, green roofs have features and values that early adopters are ready to experiment with in small markets, thereby creating awareness of the technology. Termed as disruptive technologies, green roofs can become competitive within the mainstream market against established products. The challenge in green roof construction is to find the correct balance between idealistic principles and leading edge design. This paper presented case studies to examine the following 6 aspects of design fundamentals to the creation of inspirational green roofs: the use of colour; experimentation with materials and technology; incorporation of texture, form, and pattern; definition of space; engagement of vistas; and, principles of bio-regionalism. It was concluded that good design is not enough to lead to widespread green roof implementation. It was emphasized that change will occur primarily because of the benefits acquired through implementation. 11 refs., 7 figs.

  6. Collaborative integral design of active roofs

    NARCIS (Netherlands)

    Zeiler, W.; Quanjel, E.M.C.J.; Borsboom, W.A.

    2009-01-01

    The application of photo-voltaic elements is the most economical on the roof. Still this often leads to severe problems due to poor coordination of all the design and practical aspects involved. This paper describes the research methodology, based on Methodical Design, as used in a design approach

  7. Design breakthrough in roof support systems

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    The technical experts of the Mining Services sections of Monier Resources Australia have designed and developed a superior roof system for installation in underground mines. The Monier Big Bag Grout Chock is a patented system utilising pumped grout. The advantages of grout chocks over conventional timber chocks are many and varied.

  8. Cathodic Protection Design Algorithms for Refineries Aboveground Storage Tanks

    Directory of Open Access Journals (Sweden)

    Kosay Abdul sattar Majbor

    2017-12-01

    Full Text Available Storage tanks condition and integrity is maintained by joint application of coating and cathodic protection. Iraq southern region rich in oil and petroleum product refineries need and use plenty of aboveground storage tanks. Iraq went through conflicts over the past thirty five years resulting in holding the oil industry infrastructure behind regarding maintenance and modernization. The primary concern in this work is the design and implementation of cathodic protection systems for the aboveground storage tanks farm in the oil industry. Storage tank external base area and tank internal surface area are to be protected against corrosion using impressed current and sacrificial anode cathodic protection systems. Interactive versatile computer programs are developed to provide the necessary system parameters data including the anode requirements, composition, rating, configuration, etc. Microsoft-Excel datasheet and Visual Basic.Net developed software were used throughout the study in the design of both cathodic protection systems. The case study considered in this work is the eleven aboveground storage tanks farm situated in al-Shauiba refinery in southern IRAQ. The designed cathodic protection systems are to be installed and monitored realistically in the near future. Both systems were designed for a life span of (15-30 years, and all their parameters were within the internationally accepted standards.

  9. A new design for luminescent solar concentrating PV roof tiles

    NARCIS (Netherlands)

    Doudart de la Gree, G.C.H.; Papadopoulos, A.; Debije, M.G.; Cox, M.G.D.M.; Krumer, Z.; Reinders, A.H.M.E.; Rosemann, A.L.P.

    2015-01-01

    In our paper we explore the opportunity of combining luminescent solar concentrating (LSC) materials and crystalline PV solar cells in a new design for a roof tile by design-driven research on the energy performance of various configurations of the LSC PV device and on the aesthetic appeal in a roof

  10. Integral design of active energy roofs

    NARCIS (Netherlands)

    Quanjel, E.M.C.J.

    2006-01-01

    A wide variety of new products, such as photovoltaic (PV) systems and solar collectors, roof lights, ventilation devices, insulation and safety devices, is finding its way into the roofing industry. As a result many problems occurred, resulting in poor quality, unsafe working conditions and high

  11. Bugs, bees and spiders : green roof design for rare invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Gedge, D. [Livingroofs.org, London (United Kingdom); Kadas, G. [Royal Holloway Univ. of London, London (United Kingdom)

    2004-07-01

    The use of green roofs as mitigation technique for biodiversity is particularly relevant for the objectives of the London Biodiversity Partnership, particularly since London is undergoing large-scale regeneration and many of the new developments will be targeted on brownfield land. In 2002 two research projects were undertaken to create a baseline of data on how invertebrates were using the current green roofs in London. The London Biodiversity Partnership's Black Redstart Action Plan conducts research into green roofs to demonstrate how they can be maximized for biodiversity. The Black Redstart Project ensures that green roofs are used in new developments in London where such developments threaten this species. It is one of the country's rarest breeding birds, and is unique in that it is predominantly found in cities, on brownfield sites and post-industrial sites. Three green roof laboratories were established at 2 sites in London to investigate how substrates, substrate depths and planting affects the fauna associated with brownfields and green roofs in London. Although conservationists in London have urged many developers to provide green roofs to help the Black Redstart, there is concern that many of these roofs do no provide the proper support for the species. In some cases roofs are constructed of commercially driven products such as sedum mats that do provide habitat for some rare invertebrates but are not as supportive of a greater diversity of species as they could be due to the design process and a lack of knowledge of green roof technology. It was suggested that there is a need for cooperation between ecologists and Architects in order to achieve the habitat. 18 refs., 6 figs.

  12. Probabilistic economic analysis of green roof benefits for policy design

    International Nuclear Information System (INIS)

    Clark, C.; Adriaens, P.; Talbot, B.

    2006-01-01

    The installation costs of green roofs continue to deter widespread use of green roof technology. Analyses of the boundary conditions for the cost differential between a green roof and a conventional roof are usually compared to environmental benefits such as storm water reduction and building energy savings. However, evidence is emerging that green roofs may play a role in urban air quality improvement. This paper discussed a methodology for developing probabilistic ranges of benefits and cost analyses. A probabilistic analysis was conducted to prepare a generalized cost-benefit analysis for application to a range of green roof projects. Environmental benefits of roof greening were quantified on a per unit surface area to assess environmental impact at the building scale. Parameters included conventional and green roof installation costs; storm water fees and fee reductions for green roofs; energy costs due to heat flux and the resultant savings through the installation of a green roof and the additional economic valuation of the public health benefits due to air pollution mitigation. Results were then integrated into an economic model to determine the length of time required for a return on investment in a green roof, assuming that a traditional roof would require replacement after 20 years. A net present value analysis was performed for an average-sized university roof. Results of the study showed that a valuation of environmental benefits can reduce the time required for a return on investment in a moderately priced green roof. While reduced installation costs reduced the time required for a return on investment, optimizing the green roof system for maximum environmental benefit had a greater potential to provide a higher return. It was concluded that the benefit of improved air quality should not be ignored by green roof policy-makers as a valuation tool. 10 refs., 3 tabs., 1 fig

  13. Design considerations for large roof-integrated photovoltaic arrays

    Energy Technology Data Exchange (ETDEWEB)

    Ropp, M.E.; Begovic, M.; Rohatgi, A. [Georgia Inst. of Tech., Atlanta, GA (United States); Long, R. [Georgia Institute of Technology, Atlanta (United States). Office of Facilities

    1997-01-01

    This paper describes calculations and modeling used in the design of the photovoltaic (PV) array built on the roof of the Georgia Tech Aquatic Center, the aquatic sports venue for the 1996 Olympic and Paralympic Games. The software package PVFORM (version 3.3) was extensively utilized; because of its importance to this work, it is thoroughly reviewed here. Procedures required to adapt PVFORM to this particular installation are described. The expected behavior and performance of the system, including maximum power output, annual energy output and maximum expected temperature, are then presented, and the use of this information in making informed design decisions is described. Finally, since the orientation of the PV array is not optimal, the effect of the unoptimized array orientation on the system`s performance is quantified. (author)

  14. Field Evaluation of Four Novel Roof Designs for Energy-Efficient Manufactured Homes

    Energy Technology Data Exchange (ETDEWEB)

    Levy, E. [Levy Partnership Inc., New York, NY (United States); Dentz, J. [Levy Partnership Inc., New York, NY (United States); Ansanelli, E. [Levy Partnership Inc., New York, NY (United States); Barker, G. [Levy Partnership Inc., New York, NY (United States); Rath, P. [Levy Partnership Inc., New York, NY (United States); Dadia, D. [Levy Partnership Inc., New York, NY (United States)

    2015-12-01

    A five-bay roof test structure was built, instrumented and monitored in an effort to determine through field testing and analysis the relative contributions of select technologies toward reducing energy use in new manufactured homes. The roof structure in Jamestown, California was designed to examine how differences in roof construction impact space conditioning loads, wood moisture content and attic humidity levels. Conclusions are drawn from the data on the relative energy and moisture performance of various configurations of vented and sealed attics.

  15. Design strategies for integration of green roofs in sustainable housing

    Directory of Open Access Journals (Sweden)

    Avi Friedman

    2015-12-01

    Full Text Available Green roofs are the integration of plant material and its supporting structures in buildings. Such an approach provides a habitat for local flora and fauna, helps manage storm water, reduces heat demand in winter and the cooling load in the summer, enhances the aesthetic values of dwellings, provides the occupants with comfort and amenities and strengthens environmental responsibility. Because roofs represent approximately 40 percent to 50 percent of the surfaces in urban areas, green roofs have an important role in drainage and as a result water management as well. In fact, when a green roof is installed on 50 percent or more of the roof’s surface, it guarantees 2 points and can contribute 7 additional points toward LEED certification - almost 20 percent of the required rating. This paper classifies green roofs and offers strategies for their integration in residential buildings and examines their benefits, construction principles and applications.

  16. Towards a reliable design of facade and roof elements against wind loading

    NARCIS (Netherlands)

    Geurts, C.P.W.; Staalduinen, P.C. van; Wit, M.S. de

    2004-01-01

    The most vulnerable parts of buildings with respect to wind loading are facades and roofs. Current standards on wind loading provide data to determine design loads for the elements in facades and roofs. These data are available for a limited number of simple building shapes. Up to now there is no

  17. Collaborative Design Strategy: Knowledge exchange for roof design

    NARCIS (Netherlands)

    Zeiler, W.; Quanjel, E.M.C.J.; Roozenburg, N.; Chen, L-L; Stappers, P.J.

    2011-01-01

    In the (Dutch) Building Industry sub optimal use of knowledge by participants during the design phase causes damage and failure costs, as well as it hinders innovative sustainable solutions. Therefore a design tool was developed to support design knowledge exchange between different design team

  18. Hot trends in design : chic sustainability, unique driving factors and boutique green roofs

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez, L.S. [American Society of Landscape Architects, Washington, DC (United States)]|[Greenroofs.com, Alpharetta, GA (United States); Kiers, K. [Greenroofs.com, Alpharetta, GA (United States)

    2007-07-01

    Green roofs are well known for their ecological benefits but less for their architectural usage. Green roofs offer more to the urban landscape than simply ecological, economic and aesthetic attributes of storm water management, temperature and energy reduction, and provision of additional green space. This paper focused on the top ten architectural trends in vegetated rooftop design. It addressed issues regarding client demands for green roofs and questioned if green roofs should be defined solely by their function as an ecological cover. The top ten trends revealed out-of-the ordinary applications, specialty designs and unusual projects on the boards. The paper looked beyond storm water and heat islands, and explored plans for innovative recreation, including a rooftop ski slope in Delft, the Netherlands, and a converted helipad turned into temporary grass tennis court in Dubai. The paper also presented less typical green roof market drivers, such as a doggie green space for a 10-year old, 9-pound Yorkie and a rooftop garden with plants from the Bible as a teaching laboratory for ministers. Other proposed projects that were discussed included plans for rice paddies on rooftop farms in China and the Vancouver Olympic Village with 50 per cent green roof coverage. The top ten list was organized under the following topics: boutique green roofs; sports and recreation; living roofs and living walls; eco resorts, hotels and therapeutic gardens; food on the roof; cutting edge applications; government and big box applications, cool green residences; mega green roofs; and, visionary proposed projects. 77 refs., 77 figs.

  19. Roof assembly

    CSIR Research Space (South Africa)

    De Villiers, A

    2010-01-01

    Full Text Available The objective of this chapter is to provide sustainability criteria for roof system design that can be used by planners, designers and developers as a planning, design and development guide for sustainable building projects....

  20. Design and performance of a novel innovative roofing system for tropical landed houses

    International Nuclear Information System (INIS)

    Al-Obaidi, Karam M.; Ismail, Mazran; Abdul Rahman, Abdul Malek

    2014-01-01

    Highlights: • Constructing a new design of sustainable roofing systems. • An innovative roofing system (IRS) for tropical landed houses is proposed. • Separate solar heat from useful natural light by physical form. • The IRS can maintain an illuminance level of approximately 86–100% below 2000 lux. • The IRS can reduce the attic air temperature by 5.4 °C and the indoor air temperature by 2.1 °C. - Abstract: An innovative roofing system (IRS) is designed to deliver an abundant and uniform amount of cool natural light from the roof with reduced heat gain effect for tropical residential buildings (3 m height) in Malaysia. Studies revealed that several passive and active solar techniques can be integrated to form a roofing system to separate solar heat from useful natural light at the attic zone before heat reaches the occupied space. The IRS design is specified and proposed by using glazing technology (polycarbonate), pigment technique (reflective and radiative), as well as ventilation process (hybrid turbine ventilator) applied at the attic zone to represent a new model of sustainable roofing design. The aim of this research is to demonstrate the effectiveness of the design concept without the need for any chemical, complex, or expensive solar design techniques. The methodology was conducted on a series of field studies in a standard room model at Universiti Sains Malaysia. Three different roofing systems are investigated to identify the IRS performance in both dark and daylight conditions to determine the effect of natural light on the indoor environment. The outcomes of the design show that the IRS was able to reduce the indoor air temperature compared with conventional roofing system by approximately 2.1 °C under daylight condition. Results showed that the difference in the IRS (daylight–dark) condition was 0.31 °C compared to that in the conventional roofing system at 0.8 °C. Furthermore, the level of mean radiant temperature compared with

  1. Field Evaluation of Four Novel Roof Designs for Energy-Efficient Manufactured Homes

    Energy Technology Data Exchange (ETDEWEB)

    Levy, E. [ARIES Collaborative, New York, NY (United States); Dentz, J. [ARIES Collaborative, New York, NY (United States); Ansanelli, E. [ARIES Collaborative, New York, NY (United States); Barker, G. [ARIES Collaborative, New York, NY (United States); Rath, P. [ARIES Collaborative, New York, NY (United States); Dadia, D. [ARIES Collaborative, New York, NY (United States)

    2015-12-03

    "9A five-bay roof test structure was built, instrumented and monitored in an effort to determine through field testing and analysis the relative contributions of select technologies toward reducing energy use in new manufactured homes. The roof structure in Jamestown, California was designed to examine how differences in roof construction impact space conditioning loads, wood moisture content and attic humidity levels. Conclusions are drawn from the data on the relative energy and moisture performance of various configurations of vented and sealed attics.

  2. Pre-Rationalized Parametric Designing of Roof Shells Formed by Repetitive Modules of Catalan Surfaces

    Directory of Open Access Journals (Sweden)

    Jolanta Dzwierzynska

    2018-04-01

    Full Text Available The aim of the study is to develop an original, methodical, and practical approach to the early stages of parametric design of roof shells formed by repetitive modules of Catalan surfaces. It is presented on the example of designing the roof shells compound of four concrete elements. The designing process proposed by us consists in linking geometric shaping of roofs’ models with their structural analysis and optimization. Contrary to other methods, which use optimization process in order to find free roof forms, we apply it in order to explore and improve design alternatives. It is realized with the application of designing tools working in Rhinoceros 3D software. The flexible scripts elaborated by us, in order to achieve roofs’ models of regular and symmetrical shapes, are converted into simulation models to perform structural analysis. It is mainly focused on how the roof shells perform dependently on their geometric characteristics. The simulation enables one to evaluate various roof shells’ shapes, as well as to select an optimal design solution. The proposed approach to the conceptual design process may drive the designing to achieve geometric and structural forms which not only follow the design intentions but also target better results.

  3. Design of evaporative-cooling roof for decreasing air temperatures in buildings in the humid tropics

    Science.gov (United States)

    Kindangen, Jefrey I.; Umboh, Markus K.

    2017-03-01

    This subject points to assess the benefits of the evaporative-cooling roof, particularly for buildings with corrugated zinc roofs. In Manado, many buildings have roofed with corrugated zinc sheets; because this material is truly practical, easy and economical application. In general, to achieve thermal comfort in buildings in a humid tropical climate, people applying cross ventilation to cool the air in the room and avoid overheating. Cross ventilation is a very popular path to achieve thermal comfort; yet, at that place are other techniques that allow reducing the problem of excessive high temperature in the room in the constructions. This study emphasizes applications of the evaporative-cooling roof. Spraying water on the surface of the ceiling has been executed on the test cell and the reuse of water after being sprayed and cooled once more by applying a heat exchanger. Initial results indicate a reliable design and successfully meet the target as an effective evaporative-cooling roof technique. Application of water spraying automatic and cooling water installations can work optimally and can be an optimal model for the cooling roof as one of the green technologies. The role of heat exchangers can lower the temperature of the water from spraying the surface of the ceiling, which has become a hot, down an average of 0.77° C. The mass flow rate of the cooling water is approximately 1.106 kg/h and the rate of heat flow is around 515 Watt, depend on the site.

  4. Stormwater runoff mitigation and nutrient leaching from a green roof designed to attract native pollinating insects

    Science.gov (United States)

    Fogarty, S.; Grogan, D. S.; Hale, S. R.

    2013-12-01

    A green roof is typically installed for one of two reasons: to mitigate the 'urban heat island' effect, reducing ambient temperatures and creating energy savings, or to reduce both the quantity and intensity of stormwater runoff, which is a major cause of river erosion and eutrophication. The study of green roofs in the United States has focused on commercial systems that use a proprietary expanded shale or clay substrate, along with succulent desert plants (mainly Sedum species). The green roof has the potential not only to provide thermal insulation and reduce storm runoff, but also to reclaim some of the natural habitat that has been lost to the built environment. Of special importance is the loss of habitat for pollinating insects, particularly native bees, which have been in decline for at least two decades. These pollinators are essential for crop production and for the reproduction of at least 65% of wild plants globally. Our study involves the installation of a small (4ft by 4ft), self-designed green roof system built with readily available components from a hardware store. The garden will be filled with a soilless potting mix, combined with 15% compost, and planted with grasses and wildflowers native to the Seacoast, New Hampshire region. Some of the plant species are used by bees for nesting materials, while others provide food in the form of nectar, pollen, and seeds for bees, butterflies, hummingbirds, and granivorous birds. We monitor precipitation on the roof and runoff from the garden on a per storm basis, and test grab samples of runoff for dissolved organic nitrogen and phosphorous. Runoff and nutrient concentration results are compared to a non-vegetated roof surface, and a proprietary Green Grid green roof system. This project is designed to address three main questions of interest: 1) Can these native plant species, which potentially provide greater ecosystem services than Sedum spp. in the form of food and habitat, survive in the conditions on

  5. Collaborative Design and a Web Based Database For Active Roofs

    NARCIS (Netherlands)

    Quanjel, E.M.C.J.; Otter, den A.F.H.J.; Zeiler, W.; Wamelink, H.; Prins, M.; Geraerdts, R.

    2009-01-01

    Lack of collaboration in design teams often results in a low mutual level of understanding about the design to produce. This is due to the following intertwined aspects: a lack of integration in the team, knowledge gaps between team members and failing flows of information and communication between

  6. Design and Fabrication of a Free-Form Reciprocal Roof

    DEFF Research Database (Denmark)

    Parigi, Dario

    2015-01-01

    The paper presents the framework and the design and construction process of a freeform reciprocal pavilion realized during a one-week long workshop with the students of the 1st semester of the Master of Science in Architecture and Design, fall 2014, at Aalborg University. The workshop didactic...... of relations between design parameters and a wide array of measurable performances. Due to the reciprocal structures geometric complexity, the shape generation process is handled using the Reciprocalizer, a software tool developed by the author that embeds in a computational environment the constructional...... logic of reciprocal structures. It enables to engage in real time in iterative processes that allows unfolding the geometric complexity and turn it into a source of inspiration for expanding the design space and triggering the development of unique, adapted and integrated design solutions. Reciprocal...

  7. Building a Roll-Off Roof Observatory A Complete Guide for Design and Construction

    CERN Document Server

    Hicks, John

    2009-01-01

    Almost every practical astronomer who takes the pursuit to its second level aspires to a fixed, permanent housing for his telescope, permitting its rapid and comfortable use and avoiding hours of setting-up time for each observing session. A roll-off roof observatory is the simplest and by far the most popular observatory design for today’s practical astronomers. Building a Roll-off Roof Observatory will help you decide whether to embark on the venture and will certainly provoke your enthusiasm for the project. The author, both an amateur astronomer and professional landscape architect, answers many of the common questions asked around observatory construction covering the following topics: Site planning, zoning, and by-law requirements common to most states, towns and municipalities Opportunities for locating the observatory Tailoring the observatory for your particular use Tools and structural components required to build it Variations in footing design to suit your soil conditions Variations possible in ...

  8. Trends in the design, construction and operation of green roofs to improve the rainwater quality. State of the art

    Directory of Open Access Journals (Sweden)

    Jair Andrés Morales Mojica

    2017-07-01

    Full Text Available The green roofs appear as technology for the improvement water quality. This article identifies trends in the conditions of design, construction and operation of green roofs, which aim is to improve the quality of rainwater. A literature review was carried out in order to collect 45 original research papers from databases as Scopus, Science Direct, and Redalyc. From the information collected trends in increments and reductions in the concentrations of the main water quality parameters, seasons of the year with the best results, types of green roofs , types of substrate and most common components, construction trends (dimensions, inclination, Materials and layers and vegetation used in these systems have been determined. The results show that green roofs have the ability to neutralize acid rain. Extensive type roofs are the ones most commonly used, due to its characteristics of construction, functionality and low maintenance requirements.

  9. Quality Control through Design and Process: Gambrel Roof Truss Challenge

    Science.gov (United States)

    Ward, Dell; Jones, James

    2011-01-01

    Customers determine whether a product fulfills their needs or satisfies them. "Quality control", then, is the process of finding out what the customer wants, along with designing, producing, delivering, and servicing the product--and ultimately satisfying the customer's expectations. For many years, people considered a product to be of good…

  10. Aircraft-crash-protected roof design for the European SBWR

    International Nuclear Information System (INIS)

    Posta, B.A.; Kadar, I.; Rao, A.S.

    1995-01-01

    The European utility requirement document (EURD) places significant emphasis on aircraft crash protection of the reactor building - Alternative concepts were evaluated for protecting the dry-well head and the fuel pool from the effect of the spalling concrete for the General Electric Company's European simplified boiling water reactor (ESBWR) designs

  11. Calculating the Insulated Car Roof Opening System Components and Strength Analysis of Car Design in Its Various Embodiments

    Directory of Open Access Journals (Sweden)

    V. S. Kopytov

    2016-01-01

    designed for considered structural scheme to open a car roof with beam cross-sections and their dimensions for the roof designs under consideration assumed to be identical. Comparison of calculation results for various opening options has shown that a double-leaf roof car has a number of advantages as compared with that of the single-leaf roof. The double-leaf opening scheme allows us to use more compact and easy-to-implement hydraulic cylinders. With the double-leaf roof, a design of all power components of the car is under less loads, and therefore, in optimization of this design will be used the cross-sections of the power components of smaller area, thereby leading to reduced weight and size characteristics of the entire design. Tightness of the internal volume of the car with a double-leaf opening roof can be provided through using both the structural components to open the car roof and the cutting-edge leak-proofing and sealing materials.

  12. Review of current design methodologies to improve the safety of roof support systems, particularly in the face area in collieries.

    CSIR Research Space (South Africa)

    Canbulat, I

    1999-05-01

    Full Text Available This research report summarizes an extensive literature survey on roofbolt support design methods used worldwide, and presents the findings of extensive underground roof monitoring conducted in 29 sites at five collieries. An analysis of fall...

  13. Interdisciplinary design study of a high-rise integrated roof wind energy system

    Directory of Open Access Journals (Sweden)

    Moonen S.P.G.

    2012-10-01

    Full Text Available Today’s market in micro-wind turbines is in constant development introducing more efficient solutions for the future. Besides the private use of tower supported turbines, opportunities to integrate wind turbines in the built environment arise. The Integrated Roof Wind Energy System (IRWES presented in this work is a modular roof structure integrated on top of existing or new buildings. IRWES is build up by an axial array of skewed shaped funnels used for both wind inlet and outlet. This inventive use of shape and geometry leads to a converging air capturing inlet to create high wind mass flow and velocity toward a Vertical Axis Wind Turbine (VAWT in the center-top of the roof unit for the generation of a relatively high amount of energy. The scope of this research aims to make an optimized structural design of IRWES to be placed on top of the Vertigo building in Eindhoven; analysis of the structural performance; and impact to the existing structure by means of Finite Element Modeling (FEM. Results show that the obvious impact of wind pressure to the structural design is easily supported in different configurations of fairly simple lightweight structures. In particular, the weight addition to existing buildings remains minimal.

  14. Design and development of green roof substrate to improve runoff water quality: plant growth experiments and adsorption.

    Science.gov (United States)

    Vijayaraghavan, K; Raja, Franklin D

    2014-10-15

    Many studies worldwide have investigated the potential benefits achievable by transforming brown roofs of buildings to green roofs. However, little literature examined the runoff quality/sorption ability of green roofs. As the green roof substrate is the main component to alter the quality of runoff, this investigation raises the possibility of using a mixture of low-cost inorganic materials to develop a green roof substrate. The tested materials include exfoliated vermiculite, expanded perlite, crushed brick and sand along with organic component (coco-peat). Detailed physical and chemical analyses revealed that each of these materials possesses different characteristics and hence a mix of these materials was desirable to develop an optimal green roof substrate. Using factorial design, 18 different substrate mixes were prepared and detailed examination indicated that mix-12 exhibited desirable characteristics of green roof substrate with low bulk density (431 kg/m(3)), high water holding capacity (39.4%), air filled porosity (19.5%), and hydraulic conductivity (4570 mm/h). The substrate mix also provided maximum support to Portulaca grandiflora (380% total biomass increment) over one month of growth. To explore the leaching characteristics and sorption capacity of developed green roof substrate, a down-flow packed column arrangement was employed. High conductivity and total dissolved solids along with light metal ions (Na, K, Ca and Mg) were observed in the leachates during initial stages of column operation; however the concentration of ions ceased during the final stages of operation (600 min). Experiments with metal-spiked deionized water revealed that green roof substrate possess high sorption capacity towards various heavy metal ions (Al, Fe, Cr, Cu, Ni, Pb, Zn and Cd). Thus the developed growth substrate possesses desirable characteristics for green roofs along with high sorption capacity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Performance-Oriented Design of Large Passive Solar Roofs : A method for the integration of parametric modelling and genetic algorithms

    NARCIS (Netherlands)

    Turrin, M.; Von Buelow, P.; Stouffs, R.M.F.; Kilian, A.

    2010-01-01

    The paper addresses the design of large roof structures for semi outdoor spaces through an investigation of a type of performance-oriented design, which aims at integrating performance evaluations in the early stages of the design process. Particularly, aiming at improving daylight and thermal

  16. Building a roll-off roof or dome observatory a complete guide for design and construction

    CERN Document Server

    Hicks, John Stephen

    2016-01-01

    Almost every practical astronomer eventually aspires to have a fixed, permanent observatory for his or her telescope. A roll-off roof or dome observatory is the answer for the most popular home observatory design.  Almost every practical astronomer eventually aspires to have a fixed, permanent observatory for his or her telescope. A roll-off roof or dome observatory is the answer for the most popular home observatory design. Building a Roll-Off or Dome Observatory will help you decide whether to embark on the venture and will certainly increase your enthusiasm for the project. The author, both an amateur astronomer and a professional landscape architect, answers many of the common questions asked about observatory construction, covering the following topics: • Zoning, and by-law requirements common to most states, towns and municipalities • Where to locate the observatory • How to tailor the observatory for your particular needs • Tools and structural components required • Possible variations in de...

  17. Optimal Fuzzy and Dynamics Design of Ecological Sandwich Panel Vessel Roofs

    Directory of Open Access Journals (Sweden)

    Heikki Martikka

    2011-01-01

    Full Text Available In this study the basic engineering principles, goals, and constraints are all combined with fuzzy methodology and applied to optimally design sandwich panel circular plate roofs for large vessels loaded statically and dynamically. These panels are made up of two stiff, strong veneer skins separated by vertical and peripheral stiffener plates. Advantages are high strength, lightweight, and sustainability. In the present approach, first the goals and constraints of the end user are identified and expressed as decision variables which are formulated using the engineering variables for materials, geometry, and function. Then same consistent fuzzy satisfaction functions are formed over the desired ranges to suit the customer's desires. The risk of extreme dynamic loadings exciting resonance is studied by natural frequency and mode analysis by FEM and analytical models. The results show the most critical locations and give guidelines for innovative remedies of the concept before detailed FEM analyses to finalize the design.

  18. A Mass Balance Model for Designing Green Roof Systems that Incorporate a Cistern for Re-Use

    Directory of Open Access Journals (Sweden)

    Manoj Chopra

    2012-11-01

    Full Text Available Green roofs, which have been used for several decades in many parts of the world, offer a unique and sustainable approach to stormwater management. Within this paper, evidence is presented on water retention for an irrigated green roof system. The presented green roof design results in a water retention volume on site. A first principle mass balance computer model is introduced to assist with the design of these green roof systems which incorporate a cistern to capture and reuse runoff waters for irrigation of the green roof. The model is used to estimate yearly stormwater retention volume for different cistern storage volumes. Additionally, the Blaney and Criddle equation is evaluated for estimation of monthly evapotranspiration rates for irrigated systems and incorporated into the model. This is done so evapotranspiration rates can be calculated for regions where historical data does not exist, allowing the model to be used anywhere historical weather data are available. This model is developed and discussed within this paper as well as compared to experimental results.

  19. ANALYSIS OF THE EFFECTS OF THE ROOFING DESIGN ON HEAT STRESS IN DAIRY COW HOUSING

    Directory of Open Access Journals (Sweden)

    Paolo Liberati

    2008-12-01

    Full Text Available A simulation model determining the heat flow exchange between housed animals and the roofing was developed considering various relevant factors: constructive materials, slope, height, orientation, latitude, external air temperature, solar load, animal position. Results show that the most important factor to reduce heat load is the insulation. For non-insulated roofing the slope and the orientation are the most relevant factors. Considering the total exchanged energy, the non insulated roof has a good nocturnal global behaviour.

  20. ANALYSIS OF THE EFFECTS OF THE ROOFING DESIGN ON HEAT STRESS IN DAIRY COW HOUSING

    OpenAIRE

    Paolo Liberati

    2008-01-01

    A simulation model determining the heat flow exchange between housed animals and the roofing was developed considering various relevant factors: constructive materials, slope, height, orientation, latitude, external air temperature, solar load, animal position. Results show that the most important factor to reduce heat load is the insulation. For non-insulated roofing the slope and the orientation are the most relevant factors. Considering the total exchanged energy, the non insulated roof ha...

  1. Green roofs

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-04-01

    Full Text Available , beetles and spiders); and the number of birds that nest in vegetated roofs (including kestrels, swallows, and wagtails). Objective The primary objective of a green roof is to create a living habitat in an otherwise barren environment, hence the use... the negative environmental impacts including plant and insect specie loss. Thus at a philosophical level green roofs support the notion “replace what you displace”. Key ecological issues that can be addressed through green roofs include: Negative effects...

  2. Analytical design method for a truss-bolt system for reinforcement of fractured coal mine roofs - illustrated with a case study

    Energy Technology Data Exchange (ETDEWEB)

    Liu, B.; Yue, Z.Q.; Tham, L.G. [University of Hong Kong, Hong Kong (China). Dept. of Civil Engineering

    2005-02-01

    This paper presents an analytical design method for the truss-bolt system in reinforcing underground fractured rock roofs in coal mines. The analytical design method is based on the mechanical analysis of the fractured rock roof with reinforcement by inclined roof bolts and a horizontal tie-rod. The mechanical analysis for the system includes a non-linear bending model for the laterally inclined roof bolts and three upper and lower bounds. The lateral resistance of the inclined roof bolts in a truss-bolt-supported roadway is examined using classical theory of a non-linear beam in bending. The paper analyses the arching action by lateral behavior of the inclined roof bolts in reinforcing the fractured roof. Based on mechanical models, the design formula concerning the lateral bolt forces, tensions in the tie-rod in the truss system, as well as the reinforcement behavior have been derived. In order to ensure that the roof truss-bolt system reinforces the coal roof effectively, a lower bound of pre-tightening forces must be applied on the tie-rod for stabilizing the fractured roof by arching action. The pre-tightening forces exerted via the tie-rod also cannot be greater than its upper bound, since the excessive tightening force will cause localized failure in the rock near the bolt tail at the abutment of the fractured roof beam. The analytical formulas for both lower and upper bounds for truss pre-tightening forces are put forward in this paper. Furthermore, the paper also presents analytical equations for designing the axial forces and dimensions for bolts in this kind of system.

  3. Performance Assessment Strategies: A computational framework for conceptual design of large roofs

    Directory of Open Access Journals (Sweden)

    Michela Turrin

    2014-01-01

    Full Text Available Using engineering performance evaluations to explore design alternatives during the conceptual phase of architectural design helps to understand the relationships between form and performance; and is crucial for developing well-performing final designs. Computer aided conceptual design has the potential to aid the design team in discovering and highlighting these relationships; especially by means of procedural and parametric geometry to support the generation of geometric design, and building performance simulation tools to support performance assessments. However, current tools and methods for computer aided conceptual design in architecture do not explicitly reveal nor allow for backtracking the relationships between performance and geometry of the design. They currently support post-engineering, rather than the early design decisions and the design exploration process. Focusing on large roofs, this research aims at developing a computational design approach to support designers in performance driven explorations. The approach is meant to facilitate the multidisciplinary integration and the learning process of the designer; and not to constrain the process in precompiled procedures or in hard engineering formulations, nor to automatize it by delegating the design creativity to computational procedures. PAS (Performance Assessment Strategies as a method is the main output of the research. It consists of a framework including guidelines and an extensible library of procedures for parametric modelling. It is structured on three parts. Pre-PAS provides guidelines for a design strategy-definition, toward the parameterization process. Model-PAS provides guidelines, procedures and scripts for building the parametric models. Explore-PAS supports the solutions-assessment based on numeric evaluations and performance simulations, until the identification of a suitable design solution. PAS has been developed based on action research. Several case studies

  4. 49 CFR 195.132 - Design and construction of aboveground breakout tanks.

    Science.gov (United States)

    2010-10-01

    ...) or more of liquefied petroleum gas (LPG) must be designed and constructed in accordance with API... constructed in accordance with API Standard 650. (4) High pressure steel tanks (i.e., internal gas or vapor...

  5. Design automation of load-bearing arched structures of roofs of tall buildings

    Science.gov (United States)

    Kulikov, Vladimir

    2018-03-01

    The article considers aspects of the possible use of arched roofs in the construction of skyscrapers. Tall buildings experience large load from various environmental factors. Skyscrapers are subject to various and complex types of deformation of its structural elements. The paper discusses issues related to the aerodynamics of various structural elements of tall buildings. The technique of solving systems of equations state method of Simpson. The article describes the optimization of geometric parameters of bearing elements of the arched roofs of skyscrapers.

  6. Case study: design, operation, maintenance and water quality management of sustainable storm water ponds for roof runoff.

    Science.gov (United States)

    Scholz, Miklas

    2004-12-01

    The purpose of this case study was to optimise design, operation and maintenance guidelines, and to assess the water treatment potential of a storm water pond system after 15 months of operation. The system was based on a combined silt trap, attenuation pond and vegetated infiltration basin. This combination was used as the basis for construction of a roof water runoff system from a single domestic property. United Kingdom Building Research Establishment and Construction Industry Research and Information Association, and German Association for Water, Wastewater and Waste design guidelines were tested. These design guidelines failed because they did not consider local conditions. The infiltration function for the infiltration basin was logarithmic. Algal control techniques were successfully applied, and treatment of rainwater runoff from roofs was found to be largely unnecessary for recycling (e.g., watering plants). However, seasonal and diurnal variations of biochemical oxygen demand, dissolved oxygen and pH were recorded.

  7. Green roofs : a watertight perspective

    Energy Technology Data Exchange (ETDEWEB)

    Honza, D. [Honza Group Inc., Columbia, MD (United States)]|[Barrett Co., Millington, NJ (United States)

    2005-07-01

    While there is a growing acceptance of the ecological benefits of green roofs, many roofing contractors view green roofs with suspicion. The roofing industry is a high-volume, low-margin cost-driven industry which promotes a minimum standard commodity mentality. Roofing and waterproofing is the largest source of claims against architects and engineers. This paper suggested that architectural firms and engineering firms can reduce many issues associated with roofing problems by investigating and understanding materials, demands of projects, and preparing thorough specifications. Long-term exposure to the sun's rays will impact the chemical make-up of the roofing material, and water can break down the surface molecular structure of the membrane. Daily, yearly and event-related temperature variations can subject membranes to thermal induced stresses. Many roofs leak as a result of abuse during construction. Understanding and anticipating the performance problems of membranes can give green roof designers the ability to address limitations through good design. The membrane for a green roof should have superior abuse resistance; elastic properties, and resistance to long-term wet or saturated environments. Flashings for green roofs must exceed minimum standards. Membranes should be tested for watertightness before components are installed using electronic field vector mapping. Overburden should be installed after the membrane installation is proven to be watertight. It was concluded that higher design standards are required for green roofs, as many traditional roof membranes fail prematurely. A review of widely used membranes in the roofing and waterproofing industry included modified bitumen; built-up roofing; cured synthetic rubber sheets; thermalplastic membranes; self-adhering modified bitumen; and rubberized asphalt. 6 refs., 2 tabs., 6 figs.

  8. Norwegian Pitched Roof Defects

    Directory of Open Access Journals (Sweden)

    Lars Gullbrekken

    2016-06-01

    Full Text Available The building constructions investigated in this work are pitched wooden roofs with exterior vertical drainpipes and wooden load-bearing system. The aim of this research is to further investigate the building defects of pitched wooden roofs and obtain an overview of typical roof defects. The work involves an analysis of the building defect archive from the research institute SINTEF Building and Infrastructure. The findings from the SINTEF archive show that moisture is a dominant exposure factor, especially in roof constructions. In pitched wooden roofs, more than half of the defects are caused by deficiencies in design, materials, or workmanship, where these deficiencies allow moisture from precipitation or indoor moisture into the structure. Hence, it is important to increase the focus on robust and durable solutions to avoid defects both from exterior and interior moisture sources in pitched wooden roofs. Proper design of interior ventilation and vapour retarders seem to be the main ways to control entry from interior moisture sources into attic and roof spaces.

  9. Prolong Your Roof's Performance: Roof Asset Management.

    Science.gov (United States)

    Teitsma, Jerry

    2001-01-01

    Discusses the roof asset management process for maintaining a roof system's integrity and value in a cost-effective manner. Included is a breakdown of roofing surface characteristics for multiply and single ply roofing systems. (GR)

  10. Green Roofs

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-08-01

    A New Technology Demonstration Publication Green roofs can improve the energy performance of federal buildings, help manage stormwater, reduce airborne emissions, and mitigate the effects of urban heat islands.

  11. Toronto green roof construction standard

    International Nuclear Information System (INIS)

    Aster, D.

    2007-01-01

    Toronto City Council adopted a green roof strategy in February 2006. This paper reviewed the by-law governing the strategy as well as the work in progress to develop minimum standards for the design and construction of green roofs in Toronto. The strategy included a series of recommendations regarding the installation of green roofs on city buildings; a pilot grant program; using the development process to encourage green roofs; and, public education and promotion. It was noted that compared to Europe, the development of standards for green roofs in North America is in its early stages. As an emerging sustainable technology, there currently are no standards incorporated into Ontario's Building Code against which Toronto can measure the design and construction of green roofs. Therefore this paper included an analysis detailing how the recommended design requirements were able to support the City's green roof policy objectives and integrate the performance criteria for green roofs previously established and supported by Toronto City Council. The key policy objectives of the City's green roof strategy were to reduce the urban heat island effect; to address stormwater management implications in terms of quality and quantity; to improve the energy budgets of individual buildings; and, to improve air quality

  12. Evaluation of Roof Bolting Requirements Based on In-Mine Roof Bolter Drilling

    Energy Technology Data Exchange (ETDEWEB)

    Syd S. Peng

    2005-10-01

    Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on this information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. For the prediction of roof geology and stability condition in real time, a micro processor was used and a program developed to monitor and record the drilling parameters of roof bolter. These parameters include feed pressure, feed flow (penetration rate), rotation pressure, rotation rate, vacuum pressure, oil temperature of hydraulic circuit, and signals for controlling machine. From the results of a series of laboratory and underground tests so far, feed pressure is found to be a good indicator for identifying the voids/fractures and estimating the roof rock strength. The method for determining quantitatively the location and the size of void/fracture and estimating the roof rock strength from the drilling parameters of roof bolter was developed. Also, a set of computational rules has been developed for in-mine roof using measured roof drilling parameters and implemented in MRGIS (Mine Roof Geology Information System), a software package developed to allow mine engineers to make use of the large amount of roof drilling parameters for predicting roof geology properties automatically. For the development of roof bolting criteria, finite element models were developed for tensioned and fully grouted bolting

  13. PV ready roofing systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The integration of PV technology into roofs of houses has become very popular in the United States, Japan, Germany and The Netherlands. There could be a considerable market in the UK for these systems, given the large number of houses that are projected to be built in the next 10 years, and taking account of increased awareness of energy issues. A significant proportion of the market share of annual installed PV is for solar PV systems installed into homes (currently 15%), this is expected to rise to 23% (900MW) by 2010. The grid connected roof and building mounted facade systems represent the fastest growing market for PV systems in Europe. In conclusion, therefore, innovative approached for fixing PV technology onto roofs have been identified for both domestic roofs and for the commercial sector. With reference to production methodologies within the roofing industry, both approaches should be capable of being designed with PV-ready connections suitable for fixing PV modules at a later date. This will help overcome the key barriers of cost of installation, skills required and the lack of retrofit potential. Based on the results of this project, Sustainable Energy together with PV Systems are keen to take forward the full research and development of PV-ready systems for both the domestic and commercial sectors.

  14. Evolution of Flat Roofs

    Directory of Open Access Journals (Sweden)

    Şt. Vasiliu

    2009-01-01

    Full Text Available Roofs are constructive subassembles that are located at the top of buildings, which toghether with perimetral walls and some elements of the infrastructure belongs to the subsystem elements that close the building. Roofs must meet resistance requirements to mechanical action, thermal insulating, waterproofing and acoustic, fire resistance, durability, economy and aesthetics. The man saw the need to build roofs from the oldest ancient times. Even if the design of buildings has an empirical character, are known and are preserved until today constructions that are made in antiquity, by the Egyptians, Greeks and Romans with architectural achievements, worthy of admiration and in present time. General composition of civil construction has been influenced throughout the evolution of construction history by the level of production forces and properties of building materials available in every historical epoch. For over five millennia, building materials were stone, wood and ceramic products (concrete was used by theRomans only as filling material.

  15. Design and Analysis on a System of PV Roof%光伏屋顶项目发电系统设计与分析

    Institute of Scientific and Technical Information of China (English)

    王艳国

    2012-01-01

    基于建筑屋顶面积大、无遮阳等具有可利用光伏屋顶发电的有利条件,本文以山西某市职中校区内的建筑物为例,从气象条件、系统运行方式、光伏电池方阵设计及并网电气设计等方面提出了综合优化设计方案。%Considering the favorable conditions such as large roof area of building with no shade to make use of photovoltaic roof generate electricity.Taking the shanxi vocational school of building for example,a system of photovoltaic roof power generation is designed based on the local natural conditions,the system operation mode, the solar energy cell array and grid connected,etc.

  16. Green roofs: potential at LANL

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, Elena M [Los Alamos National Laboratory

    2009-01-01

    strokes, heat exhaustion, and pollution that can agitate the respiratory system. The most significant savings associated with green roofs is in the reduction of cooling demands due to the green roof's thermal mass and their insulating properties. Unlike a conventional roof system, a green roof does not absorb solar radiation and transfer that heat into the interior of a building. Instead the vegetation acts as a shade barrier and stabilizes the roof temperature so that interior temperatures remain comfortable for the occupants. Consequently there is less of a demand for air conditioning, and thus less money spent on energy. At LANL the potential of green roof systems has already been realized with the construction of the accessible green roof on the Otowi building. To further explore the possibilities and prospective benefits of green roofs though, the initial capital costs must be invested. Three buildings, TA-03-1698, TA-03-0502, and TA-53-0031 have all been identified as sound candidates for a green roof retrofit project. It is recommended that LANL proceed with further analysis of these projects and implementation of the green roofs. Furthermore, it is recommended that an urban forestry program be initiated to provide supplemental support to the environmental goals of green roofs. The obstacles barring green roof construction are most often budgetary and structural concerns. Given proper resources, however, the engineers and design professionals at LANL would surely succeed in the proper implementation of green roof systems so as to optimize their ecological and monetary benefits for the entire organization.

  17. Design and Development of Low P-Emission Substrate for the Protection of Urban Water Bodies Collecting Green Roof Runoff

    Directory of Open Access Journals (Sweden)

    Agnieszka Karczmarczyk

    2017-10-01

    Full Text Available Urbanization leads to higher phosphorus (P concentration in urban catchments. Among different stormwater retention measures, green roofs are the least efficient in phosphorus retention. Moreover, much research has shown that green roofs act as sources of phosphorus, and they can emit P in significant loads. In this study low P emission green roof substrate was developed based on the proposed step by step procedure for the selection of materials including laboratory tests, column experiments, and the monitoring of the open air green roof model. Developed substrate is the mixture of crushed red brick (35% of volume, crushed limestone (20% of volume, and sand (45% of volume, and is characterized by a bulk density of 1.52 g/cm3, water permeability of 9 mm/min, water capacity of 24.6% of volume, and granulometric composition that meets the Landscaping and Landscape Development Research Society (FLL guidelines. Limestone was added to limit the potential P leaching from crushed red brick and vegetated mate consisted of Sedum album, Sedum acre, Sedum kamtschaticum, Sedum spurium, Sedum reflexum, Sedum sexangulare, Dianthus deltoides, Dianthus carthusianorum, and Thymus vulgaris. The open air model experiment was run for 319 days, from March 2015 to February 2016. The total water runoff from the green roof model amounted to 43.3% of runoff from the reference roof. The only one runoff event polluted with phosphorus was connected with the outflow of melted snow from an unfreezing green roof model.

  18. Aboveground storage tanks

    International Nuclear Information System (INIS)

    Rizzo, J.A.

    1992-01-01

    With the 1988 promulgation of the comprehensive Resource Conservation and Recovery Act (RCRA) regulations for underground storage of petroleum and hazardous substances, many existing underground storage tank (UST) owners have been considering making the move to aboveground storage. While on the surface, this may appear to be the cure-all to avoiding the underground leakage dilemma, there are many other new and different issues to consider with aboveground storage. The greatest misconception is that by storing materials above ground, there is no risk of subsurface environmental problems. it should be noted that with the aboveground storage tank (AGST) systems, there is still considerable risk of environmental contamination, either by the failure of onground tank bottoms or the spillage of product onto the ground surface where it subsequently finds its way to the ground water. In addition, there are added safety concerns that must be addressed. So what are the other specific areas of concern besides environmental to be addressed when making the decision between underground and aboveground tanks? The primary issues that will be addressed in this paper are: Safety, Product Losses, Cost Comparison of USTs vs AGSTs, Space Availability/Accessibility, Precipitation Handling, Aesthetics and Security, Pending and Existing Regulations

  19. A novel method to design water spray cooling system to protect floating roof atmospheric storage tanks against fires

    Directory of Open Access Journals (Sweden)

    Iraj Alimohammadi

    2015-01-01

    Full Text Available Hydrocarbon bulk storage tank fires are not very common, but their protection is essential due to severe consequences of such fires. Water spray cooling system is one of the most effective ways to reduce damages to a tank from a fire. Many codes and standards set requirements and recommendations to maximize the efficiency of water spray cooling systems, but these are widely different and still various interpretations and methods are employed to design such systems. This article provides a brief introduction to some possible design methods of cooling systems for protection of storage tanks against external non-contacting fires and introduces a new method namely “Linear Density Method” and compares the results from this method to the “Average Method” which is currently in common practice. The average Method determines the flow rate for each spray nozzle by dividing the total water demand by the number of spray nozzles while the Linear Density Method determines the nozzle flow rate based on the actual flow over the surface to be protected. The configuration of the system includes a one million barrel crude oil floating roof tank to be protected and which is placed one half tank diameter from a similar adjacent tank with a full surface fire. Thermal radiation and hydraulics are modeled using DNV PHAST Version 6.53 and Sunrise PIPENET Version 1.5.0.2722 software respectively. Spray nozzles used in design are manufactured by Angus Fire and PNR Nozzles companies. Schedule 40 carbon steel pipe is used for piping. The results show that the cooling system using the Linear Density Method consumes 3.55% more water than the design using the average method assuming a uniform application rate of 4.1 liters per minute. Despite higher water consumption the design based on Linear Density Method alleviates the problems associated with the Average Method and provides better protection.

  20. Influence of roof motion in LMFBR containment loading studies

    International Nuclear Information System (INIS)

    Potter, R.; Lancefield, M.J.; Sidoli, J.E.A.; Broadhouse, B.J.; Green, R.S.

    1982-01-01

    Following an HCDA the reactor roof may be threatened by coolant impact. Recent trends in CDFR roof design suggest that roof movement during the impact process may reduce the roof loading as a result of the fluid-structure interaction. The paper describes analytic studies of the phenomena, extensions to the SEURBNUK containment code to the roof flexibility and fluid-structure coupling, and results of experiments which confirm the reduced impulse and provide validation of the mathematical modelling

  1. A literature review on the improvement strategies of passive design for the roofing system of the modern house in a hot and humid climate region

    Directory of Open Access Journals (Sweden)

    Qairuniza Roslan

    2016-03-01

    Full Text Available Increase of indoor temperature compared with outdoor temperature is a major concern in modern house design. Occupants suffer from this uncomfortable condition because of overheating indoor temperature. Poor passive design causes heat to be trapped, which influences the rise in indoor temperature. The upper part, which covers the area of the roof, is the most critical part of the house that is exposed to heat caused by high solar radiation and high emissivity levels. During daytime, the roof accumulates heat, which increases the indoor temperature and affects the comfort level of the occupants. To maintain the indoor temperature within the comfort level, most house designs usually depend on mechanical means by using fans or air conditioning systems. The dependence on a mechanical ventilation system could lead to additional costs for its installation, operation, and maintenance. Thus, this study concentrates on reviews on passive design and suggests recommendations for future developments. New proposals or strategies are proposed to improve the current passive design through ventilated and cool roof systems. It is possible to achieve the comfort level inside a house throughout the day by reducing the transmitted heat into the indoor environment and eliminating the internal hot air. These recommendations could become attractive strategies in providing a comfortable indoor temperature to the occupants as well as in minimizing energy consumption.

  2. EVALUATION OF ROOF BOLTING REQUIREMENTS BASED ON IN-MINE ROOF BOLTER DRILLING

    Energy Technology Data Exchange (ETDEWEB)

    Syd S. Peng

    2003-07-15

    Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal, potash, salt etc. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on such information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. In this quarter, the field, theoretical and programming works have been performed toward achieving the research goals set in the proposal. The selected site and the field testing plan enabled us to test all three aspects of roof geological features. The development of the data interpretation methodologies and the geology mapping computer program have also been preceding well.

  3. Design, Development, and Performance Evaluation of Solar Heating System for Disinfection of Domestic Roof-Harvested Rainwater.

    Science.gov (United States)

    Akintola, O A; Sangodoyin, A Y

    2015-01-01

    A box-type solar heater was designed, constructed, and used to determine the effect of solar heating on quality of domestic roof-harvested rainwater (DRHRW). During testing, naturally contaminated DRHRW was harvested in Ibadan, Nigeria, and released into the system at 93.96 Lh(-1) (2.61 × 10(-5) m(3) s(-1)) in a continuous flow process. Water temperatures at inlet, within the heating chamber, and at outlet from the heating chamber and solar radiation were monitored at 10 min interval. Samples were collected at both inlet to and outlet from the heating chamber at 10 min interval for microbiological analysis. The highest plate stagnation temperature, under no-load condition, was 100°C. The solar water heater attained a maximum operational temperature of 75°C with 89.6 and 94.4% reduction in total viable count and total coliform count, respectively, while Escherichia coli and Staphylococcus aureus were completely eradicated at this temperature. The solar heater developed proved to be effective in enhancing potability of DRHRW in Ibadan, Nigeria. This may be an appropriate household water treatment technology for developing countries, hence, a way of resolving problem of low quality water for potable uses.

  4. Research methodology for integral design in the context of collaborative engineering for active roofs

    NARCIS (Netherlands)

    Quanjel, E.M.C.J.

    2007-01-01

    In the world of design and engineering, gaps of knowledge between these disciplines are recognized [1, 2, 3, 4]. The learning capacity of the building industry – as well as in other industries – is becoming a main issue, also within Architect-organizations [5, 6]. A model for structuring knowledge

  5. The Geometric Theory of Roof Reflector Resonators

    Science.gov (United States)

    1976-12-01

    reflector, if properly oriented, (The terms "roof-top prism ," "right-angle prism ," and - incorrectly - " Porro prism " are encountered in .the literature...Q-switch prisms ) in laser resonators have been infrequent compared to the attention given spherical mirrors. This chapter summarizes the relevant...designator (Refs 42 and 43). In one experiment, a 900 roof prism was tested in a resonator with a 70% reflecting filat mirror. Thus, in Fig. 2, the right roof

  6. Demonstration of energy savings of cool roofs

    Energy Technology Data Exchange (ETDEWEB)

    Konopacki, S.; Gartland, L.; Akbari, H. [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technologies Div.; Rainer, L. [Davis Energy Group, Davis, CA (United States)

    1998-06-01

    Dark roofs raise the summertime air-conditioning demand of buildings. For highly-absorptive roofs, the difference between the surface and ambient air temperatures can be as high as 90 F, while for highly-reflective roofs with similar insulative properties, the difference is only about 20 F. For this reason, cool roofs are effective in reducing cooling energy use. Several experiments on individual residential buildings in California and Florida show that coating roofs white reduces summertime average daily air-conditioning electricity use from 2--63%. This demonstration project was carried out to address some of the practical issues regarding the implementation of reflective roofs in a few commercial buildings. The authors monitored air-conditioning electricity use, roof surface temperature, plenum, indoor, and outdoor air temperatures, and other environmental variables in three buildings in California: two medical office buildings in Gilroy and Davis and a retail store in San Jose. Coating the roofs of these buildings with a reflective coating increased the roof albedo from an average of 0.20--0.60. The roof surface temperature on hot sunny summer afternoons fell from 175 F--120 F after the coating was applied. Summertime average daily air-conditioning electricity use was reduced by 18% (6.3 kWh/1000ft{sup 2}) in the Davis building, 13% (3.6 kWh/1000ft{sup 2}) in the Gilroy building, and 2% (0.4 kWh/1000ft{sup 2}) in the San Jose store. In each building, a kiosk was installed to display information from the project in order to educate and inform the general public about the environmental and energy-saving benefits of cool roofs. They were designed to explain cool-roof coating theory and to display real-time measurements of weather conditions, roof surface temperature, and air-conditioning electricity use. 55 figs., 15 tabs.

  7. Photovoltaic roof construction

    Energy Technology Data Exchange (ETDEWEB)

    Hawley, W.W.

    1980-02-26

    In a batten-seam roof construction employing at least one photovoltaic cell module, the electrical conduits employed with the at least one photovoltaic cell module are disposed primarily under the battens of the roof.

  8. Renovation of Roof Structure

    DEFF Research Database (Denmark)

    Kjærbye, Per Oluf H

    1997-01-01

    A 30 year old not-watertight roof based on wooden boards with roofing felt have been changed to a pitched structure with cementos plates. At the same time more thermal insulation has been placed.......A 30 year old not-watertight roof based on wooden boards with roofing felt have been changed to a pitched structure with cementos plates. At the same time more thermal insulation has been placed....

  9. Green roof Malta

    OpenAIRE

    Gatt, Antoine

    2015-01-01

    In Malta, buildings cover one third of the Island, leaving greenery in the dirt track. Green roofs are one way to bring plants back to urban areas with loads of benefits. Antoine Gatt, who manages the LifeMedGreenRoof project at the University of Malta, tells us more. http://www.um.edu.mt/think/green-roof-malta/

  10. EPA's Green Roof Research

    Science.gov (United States)

    This is a presentation on the basics of green roof technology. The presentation highlights some of the recent ORD research projects on green roofs and provices insight for the end user as to the benefits for green roof technology. It provides links to currently available EPA re...

  11. Economic and environmental evaluation model for selecting the optimum design of green roof systems in elementary schools.

    Science.gov (United States)

    Kim, JiMin; Hong, TaeHoon; Koo, Choong-Wan

    2012-08-07

    Green-roof systems offer various benefits to man and nature, such as establishing ecological environments, improving landscape and air quality, and offering pleasant living environments. This study aimed to develop an optimal-scenario selection model that considers both the economic and the environmental effect in applying GRSs to educational facilities. The following process was carried out: (i) 15 GRSs scenarios were established by combining three soil and five plant types and (ii) the results of the life cycle CO(2) analyses with the GRSs scenarios were converted to an economic value using certified emission reductions (CERs) carbon credits. Life cycle cost (LCC) analyses were performed based on these results. The results showed that when considering only the currently realized economic value, the conventional roof system is superior to the GRSs. However, the LCC analysis that included the environmental value, revealed that compared to the conventional roof system, the following six GRSs scenarios are superior (cost reduction; reduction ratio; in descending order): scenarios 13 ($195,229; 11.0%), 3 ($188,178; 10.6%), 8 ($181,558; 10.3%), 12 ($130,464; 7.4%), 2 ($124,566; 7.0%), and 7 ($113,931; 6.4%). Although the effect is relatively small in terms of cost reduction, environmental value attributes cannot be ignored in terms of the reduction ratio.

  12. Parametric study of roof diaphragm stiffness requirements

    International Nuclear Information System (INIS)

    Jones, W.D.; Tenbus, M.A.

    1991-01-01

    A common assumption made in performing a dynamic seismic analysis for a building is that the roof/floor system is open-quotes rigidclose quotes. This assumption would appear to be reasonable for many of the structures found in nuclear power plants, since many of these structures are constructed of heavily reinforced concrete having floor/roof slabs at least two feet in thickness, and meet the code requirements for structural detailing for seismic design. The roofs of many Department of Energy (DOE) buildings at the Oak Ridge Y-12 Plant in Oak Ridge, Tennessee, have roofs constructed of either metal, precast concrete or gypsum plank deck overlaid with rigid insulation, tar and gravel. In performing natural phenomena hazard assessments for one such facility, it was assumed that the existing roof performed first as a flexible diaphragm (zero stiffness) and then, rigid (infinitely stiff). For the flexible diaphragm model it was determined that the building began to experience significant damage around 0.09 g's. For the rigid diaphragm model it was determined that no significant damage was observed below 0.20 g's. A Conceptual Design Report has been prepared for upgrading/replacing the roof of this building. The question that needed to be answered here was, open-quotes How stiff should the new roof diaphragm be in order to satisfy the rigid diaphragm assumption and, yet, be cost effective?close quotes. This paper presents a parametric study of a very simple structural system to show that the design of roof diaphragms needs to consider both strength and stiffness (frequency) requirements. This paper shows how the stiffness of a roof system affects the seismically induced loads in the lateral, vertical load resisting elements of a building and provides guidance in determining how open-quotes rigidclose quotes a roof system should be in order to accomplish a cost effective design

  13. Plant landscape design and its social service function of Shanghai Qibao GaoXian Roof Garden Market

    Directory of Open Access Journals (Sweden)

    Dai Wenbin

    2017-02-01

    Full Text Available With the rapid development of urban social economy,the original green area of the cities has been decreasing continually. In order to meet the humanistic,natural and economic demands of the urban green space,this paper takes the Shanghai Qibao GaoXian Roof Garden Market as an example further studing the social service functions of the market such as leisure meeting,garden life,flower market,education on nature,festival exhibition and so on.

  14. Advanced Energy Efficient Roof System

    Energy Technology Data Exchange (ETDEWEB)

    Jane Davidson

    2008-09-30

    options considered to date are not ideal. One approach is to insulate between the trusses at the roof plane. The construction process is time consuming and costs more than conventional attic construction. Moreover, the problems of air infiltration and thermal bridges across the insulation remain. Another approach is to use structurally insulated panels (SIPs), but conventional SIPs are unlikely to be the ultimate solution because an additional underlying support structure is required except for short spans. In addition, wood spline and metal locking joints can result in thermal bridges and gaps in the foam. This study undertook a more innovative approach to roof construction. The goal was to design and evaluate a modular energy efficient panelized roof system with the following attributes: (1) a conditioned and clear attic space for HVAC equipment and additional finished area in the attic; (2) manufactured panels that provide structure, insulation, and accommodate a variety of roofing materials; (3) panels that require support only at the ends; (4) optimal energy performance by minimizing thermal bridging and air infiltration; (5) minimal risk of moisture problems; (6) minimum 50-year life; (7) applicable to a range of house styles, climates and conditions; (8) easy erection in the field; (9) the option to incorporate factory-installed solar systems into the panel; and (10) lowest possible cost. A nationwide market study shows there is a defined market opportunity for such a panelized roof system with production and semi-custom builders in the United States. Senior personnel at top builders expressed interest in the performance attributes and indicate long-term opportunity exists if the system can deliver a clear value proposition. Specifically, builders are interested in (1) reducing construction cycle time (cost) and (2) offering increased energy efficiency to the homebuyer. Additional living space under the roof panels is another low-cost asset identified as part of

  15. Composite hollow core vaults: An analysis of the Fusée Céramic System and the design of form-active environmental friendly roofs

    Directory of Open Access Journals (Sweden)

    Wim Kamerling

    2016-03-01

    Full Text Available Just after World-War II building materials were scarce, architects and engineers had to design buildings using not much cement and steel. In French an architect, Jacques Couëlle, had invented a system with céramique infill elements to reduce for structures of concrete the self-weight and need of cement and steel. In the fifties and sixties of the twentieth century these céramique elements, known as Fusée Céramique elements, were used widely in France, North Africa and the Netherlands, mostly for barrel vaults and shells. Nowadays most of these structures are pulled down and the remaining buildings do not meet the demands of the present concerning climate comfort, insulation and safety. This thesis analyses the structural design of cylindrical Fusée Céramique roofs in the context of those days. The effect of the céramique infill elements for the time dependent deformations, stiffness and load bearing capacity, including second order, is studied. To save the few remaining buildings for the coming generations the possibilities to strengthen these structures with slender light elements of steel are explored. The effect of the strengthening is described for a Fusée Céramique vault, designed and constructed in the past. Reinforced concrete is a widely used building material with many advantages. Unfortunately the production of both reinforcement and cement is quite energy intensive and causes the emission of greenhouse gasses as NO2, NO and CO2. Reducing the need of cement is a relative simple way to reduce the emission of these greenhouse gasses. In practice roofs are seldom really flat but curved or at least slightly inclined, to drain rainwater and snow. Structurally curved structures, transferring loads as a surface-active or form-active structural system, are very efficient. The need of material and the self-weight is pretty low. This can be very useful if in the future the potentials of roofs for producing food and energy are used more

  16. IMPROVED ROOF STABILIZATION TECHNOLOGIES

    International Nuclear Information System (INIS)

    Ebadian, M.A.

    1999-01-01

    Many U.S. Department of Energy (DOE) remediation sites have performed roof repair and roof replacement to stabilize facilities prior to performing deactivation and decommissioning (D and D) activities. This project will review the decision criteria used by these DOE sites, along with the type of repair system used for each different roof type. Based on this information, along with that compiled from roofing experts, a decision-making tool will be generated to aid in selecting the proper roof repair systems. Where appropriate, innovative technologies will be reviewed and applied to the decision-making tool to determine their applicability. Based on the results, applied research and development will be conducted to develop a method to repair these existing roofing systems, while providing protection for the D and D worker in a cost-efficient manner

  17. IMPROVED ROOF STABILIZATION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    M.A. Ebadian, Ph.D.

    1999-01-01

    Many U.S. Department of Energy (DOE) remediation sites have performed roof repair and roof replacement to stabilize facilities prior to performing deactivation and decommissioning (D&D) activities. This project will review the decision criteria used by these DOE sites, along with the type of repair system used for each different roof type. Based on this information, along with that compiled from roofing experts, a decision-making tool will be generated to aid in selecting the proper roof repair systems. Where appropriate, innovative technologies will be reviewed and applied to the decision-making tool to determine their applicability. Based on the results, applied research and development will be conducted to develop a method to repair these existing roofing systems, while providing protection for the D and D worker in a cost-efficient manner.

  18. How To Choose the Right Roofing System.

    Science.gov (United States)

    Carl, David

    2001-01-01

    Lists the factors that must be considered when specifying a roof for an existing or new facility. Factors discussed include cost, longevity, value of operations, warranties, building structure and design, and old vs. new system compatibility. (GR)

  19. Eliciting maize defense pathways aboveground attracts belowground biocontrol agents.

    Science.gov (United States)

    Filgueiras, Camila Cramer; Willett, Denis S; Pereira, Ramom Vasconcelos; Moino Junior, Alcides; Pareja, Martin; Duncan, Larry W

    2016-11-04

    Plant defense pathways mediate multitrophic interactions above and belowground. Understanding the effects of these pathways on pests and natural enemies above and belowground holds great potential for designing effective control strategies. Here we investigate the effects of aboveground stimulation of plant defense pathways on the interactions between corn, the aboveground herbivore adult Diabrotica speciosa, the belowground herbivore larval D. speciosa, and the subterranean ento-mopathogenic nematode natural enemy Heterorhabditis amazonensis. We show that adult D. speciosa recruit to aboveground herbivory and methyl salicylate treatment, that larval D. speciosa are relatively indiscriminate, and that H. amazonensis en-tomopathogenic nematodes recruit to corn fed upon by adult D. speciosa. These results suggest that entomopathogenicnematodes belowground can be highly attuned to changes in the aboveground parts of plants and that biological control can be enhanced with induced plant defense in this and similar systems.

  20. Eliciting maize defense pathways aboveground attracts belowground biocontrol agents

    Science.gov (United States)

    Filgueiras, Camila Cramer; Willett, Denis S.; Pereira, Ramom Vasconcelos; Moino Junior, Alcides; Pareja, Martin; Duncan, Larry W.

    2016-01-01

    Plant defense pathways mediate multitrophic interactions above and belowground. Understanding the effects of these pathways on pests and natural enemies above and belowground holds great potential for designing effective control strategies. Here we investigate the effects of aboveground stimulation of plant defense pathways on the interactions between corn, the aboveground herbivore adult Diabrotica speciosa, the belowground herbivore larval D. speciosa, and the subterranean ento-mopathogenic nematode natural enemy Heterorhabditis amazonensis. We show that adult D. speciosa recruit to aboveground herbivory and methyl salicylate treatment, that larval D. speciosa are relatively indiscriminate, and that H. amazonensis en-tomopathogenic nematodes recruit to corn fed upon by adult D. speciosa. These results suggest that entomopathogenicnematodes belowground can be highly attuned to changes in the aboveground parts of plants and that biological control can be enhanced with induced plant defense in this and similar systems. PMID:27811992

  1. Decision Guide for Roof Slope Selection

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, T.R.

    1988-01-01

    This decision guide has been written for personnel who are responsible for the design, construction, and replacement of Air Force roofs. It provides the necessary information and analytical tools for making prudent and cost-effective decisions regarding the amount of slope to provide in various roofing situations. Because the expertise and experience of the decision makers will vary, the guide contains both basic slope-related concepts as well as more sophisticated technical data. This breadth of information enables the less experienced user to develop an understanding of roof slope issues before applying the more sophisticated analytical tools, while the experienced user can proceed directly to the technical sections. Although much of this guide is devoted to the analysis of costs, it is not a cost-estimating document. It does, however, provide the reader with the relative costs of a variety of roof slope options; and it shows how to determine the relative cost-effectiveness of different options. The selection of the proper roof slope coupled with good roof design, a quality installation, periodic inspection, and appropriate maintenance and repair will achieve the Air Force's objective of obtaining the best possible roofing value for its buildings.

  2. Improved roof stabilization technologies

    International Nuclear Information System (INIS)

    Ebadian, M.A.

    1998-01-01

    Decontamination and decommissioning (D and D) activities require that personnel have access to all areas of structures, some of which are more than 40 years old. In many cases, these structures have remained in a standby condition for up to 10 years; few preventative maintenance activities have been performed on them because of lack of funding or a defined future plan of action. This situation has led to deteriorated building conditions, resulting in potential personnel safety hazards. In addition, leaky roofs allow water to enter the buildings, which can cause the spread of contamination and increase building deterioration, worsening the already unsafe working conditions. To ensure worker safety and facilitate building dismantlement, the assessment of roof stabilization techniques applicable to US Department of Energy (DOE) structures has become an important issue. During Fiscal year 1997 (FY97), a comprehensive reliability-based model for the structural stabilization analysis of roof system in complex structures was developed. The model consists of three major components: a material testing method, a deterministic structural computer model, and a reliability-based optimization, and probabilistic analyses of roof structures can be implemented. Given site-specific needs, this model recommends the most appropriate roof stabilization system. This model will give not only an accurate evaluation of the existing roof system in complex structures, but it will also be a reliable method to aid the decision-making process. This final report includes in its appendix a Users' Manual for the Program of Deterministic and Reliability Analysis of Roof Structures

  3. Strength and stiffness capacity utilisation of timber members in roof ...

    African Journals Online (AJOL)

    C Brand Wessels, Nils-Olaf Petersen. Abstract. The main objective of this study was to determine which property, of the six strength and stiffness properties used in structural timber design, was the most influential in the design of nail-plated roof trusses. Thirty recently completed nail-plated roof truss designs were randomly ...

  4. Green Roofs for Stormwater Management

    Science.gov (United States)

    This project evaluated green roofs as a stormwater management tool. Results indicate that the green roofs are capable of removing 40% of the annual rainfall volume from a roof through retention and evapotranspiration. Rainfall not retained by green roofs is detained, effectively...

  5. Green roofs; Les toitures vegetalisees

    Energy Technology Data Exchange (ETDEWEB)

    Seghier, C.

    2006-03-15

    Impervious surface coverage keeps spreading in cities. Streets, sidewalks, parking lots and roofs are waterproof, meaning greater amounts of water to channel and treat and higher flood risks during heavy rainfalls. Green roofing can play a key part in addressing this alarming issue. There are three types of green roofs: extensive, semi-intensive and intensive. The extensive green roof technique uses a thin soil covering with a variety of species providing year-round plant coverage. The plants are not necessarily horticultural in which case routine maintenance is minimal. No watering is needed. Usually extensive green roofs create an ecosystem. The semi-intensive green roof technique uses a soil covering of average thickness and serves to create decorative roofing. Although maintenance is moderate, watering is essential. The intensive green roof technique produces a terrace roof garden. Another advantage of green roofs is they increase the life cycle of the sealing. Roof sealing protection may see the span of its life cycle, now at about fifteen years, doubled if the building has a green roof. planning professionals still know very little about green roofing solutions. Yet, green roofing provides unquestionable ecological qualities and thermal and acoustic performance that have proven to be environmentally friendly. Yet France lags behind northern European countries in green roofing. The Germans, Swiss, Austrians, Scandinavians and Dutch have been using the technique for more than twenty years. (A.L.B.)

  6. National construction, Denmark. Flat roofs

    Energy Technology Data Exchange (ETDEWEB)

    Rode, C

    1995-04-01

    The Paris meeting of IEA Annex 24 (held in the spring of 1991) declared a set of typical building constructions, the Heat, Air and Moisture characteristics of which should be dealt with as part of the Annex work. Each type of construction was assigned to one or more countries as their National Construction, and it has been the responsibility of each country to prepare a report on what may be regarded as common knowledge in the country on the hygrothermal behaviour of their construction. This knowledge is in part due to experimental work carried out by research bodies in the countries, and due to experience form practice. This report has two main sections: Section 2 gives a general overview of the design of the most common variants of flat roofs and common knowledge reported for such roofs. Section 3 gives an account of research projects carried out in Denmark on flat roofs to analyze their hygrothermal performance. Whenever possible, an emphasis will be put on the hygrothermal consequences of thermally insulating such constructions. (EG) 19 refs.

  7. Perspectives of roof bolt use in the Kuzbass

    Energy Technology Data Exchange (ETDEWEB)

    Shirokov, A P

    1983-10-01

    Use of roof bolting for strata control in mine roadways and underground chambers in Kuzbass mines is discussed. Use of roof bolting in the Kuzbass is increasing. In 1982 roof bolting was used in 50% of workings driven in the basin; in 15 coal mines roof bolting was the predominant method for strata control. Use of roof bolting rather than timber props permitted advance rate of mine drivage in the Kuzbass to be increased by 1.5-2.0 times. Interaction between roof bolts and rock strata is analyzed. The following bolt types are considered: timber roof bolts, steel expansion shell bolts and thread bar bolts. Bolt design is shown, along with methods for roof bolt installation in roadways and chambers. Roof bolting during level, inclined or steep seam mining, for strata control at junctions of working faces with gate roads, at junctions of 2 roadways, in coal chutes, in hydraulic mines, during thick seam slicing with hardening stowing and longwall mining with hydraulic stowing is analyzed. Effects of roof bolting on strata control efficiency in steep coal mines employing AShchM systems are evaluated.

  8. Creating a marketplace for green roofs in Chicago

    International Nuclear Information System (INIS)

    Vitt Sale, L.; Berkshire, M.

    2004-01-01

    Since 2003, the Chicago Department of Planning and Development has been encouraging city developers to consider installing green roofs on buildings in Chicago, with the belief that this practice results in mitigation of the urban heat island effect, cleaner runoff leaving green roofs, sound attenuation, aesthetic value, oxygen production, and mitigation of carbon dioxide emissions. However, the benefits to developers, which include reduced stormwater runoff, extended roof life and energy savings, in total do not offset the first cost premium of a green roof. Despite this, and with no mandate requiring green roofs, the marketplace is growing. After seeing green roofs on a tour in Europe, the mayor of Chicago encouraged the first design and installation of a 20,300 square foot demonstration green roof in Chicago, and other city-sponsored pilot projects followed shortly after. Since then, the number of green roofs in Chicago has grown to over one million square feet. A map of Chicago showing locations of most of the projects was presented. It was suggested that lower prices for green roofs, higher energy costs and an inclination to invest in long-term strategies would accelerate the market. In an effort to engage the public in dialogue, the Department of Planning and Development held seminars to promote the benefits of green roofs . Participants had many questions about the applicability of green roofs to Chicago, expressing skepticism that Chicago's climate would provide the same benefits as in Europe. Other concerns were expressed regarding the devaluation of property values resulting from placing green roofs on buildings; doubts about roof leaks; maintenance practices; and, bugs and mold. Since the first cost premium of the system remains a question, most participants expressed interest in some kind of incentive program, but remained open-minded if benefits could be proved. 6 figs

  9. Creating a marketplace for green roofs in Chicago

    Energy Technology Data Exchange (ETDEWEB)

    Vitt Sale, L. [Wright and Co. Chicago, IL (United States); Berkshire, M. [City of Chicago, IL (United States)

    2004-07-01

    Since 2003, the Chicago Department of Planning and Development has been encouraging city developers to consider installing green roofs on buildings in Chicago, with the belief that this practice results in mitigation of the urban heat island effect, cleaner runoff leaving green roofs, sound attenuation, aesthetic value, oxygen production, and mitigation of carbon dioxide emissions. However, the benefits to developers, which include reduced stormwater runoff, extended roof life and energy savings, in total do not offset the first cost premium of a green roof. Despite this, and with no mandate requiring green roofs, the marketplace is growing. After seeing green roofs on a tour in Europe, the mayor of Chicago encouraged the first design and installation of a 20,300 square foot demonstration green roof in Chicago, and other city-sponsored pilot projects followed shortly after. Since then, the number of green roofs in Chicago has grown to over one million square feet. A map of Chicago showing locations of most of the projects was presented. It was suggested that lower prices for green roofs, higher energy costs and an inclination to invest in long-term strategies would accelerate the market. In an effort to engage the public in dialogue, the Department of Planning and Development held seminars to promote the benefits of green roofs . Participants had many questions about the applicability of green roofs to Chicago, expressing skepticism that Chicago's climate would provide the same benefits as in Europe. Other concerns were expressed regarding the devaluation of property values resulting from placing green roofs on buildings; doubts about roof leaks; maintenance practices; and, bugs and mold. Since the first cost premium of the system remains a question, most participants expressed interest in some kind of incentive program, but remained open-minded if benefits could be proved. 6 figs.

  10. Green Roofs: Federal Energy Management Program (FEMP) Federal Technology Alert

    Energy Technology Data Exchange (ETDEWEB)

    Scholz-Barth, K.; Tanner, S.

    2004-09-01

    In a ''green roof,'' a layer of vegetation (e.g., a roof garden) covers the surface of a roof to provide shade, cooler indoor and outdoor temperatures, and effective storm-water management to reduce runoff. The main components are waterproofing, soil, and plants. There are two basic kinds: intensive and extensive. An intensive green roof often features large shrubs and trees, and it can be expensive to install and maintain. An extensive green roof features shallow soil and low-growing, horizontally spreading plants that can thrive in the alpine conditions of many rooftops. These plants do not require a lot of water or soil, and they can tolerate a significant amount of exposure to the sun and wind. This Federal Technology Alert focuses on the benefits, design, and implementation of extensive green roofs and includes criteria for their use on federal facilities.

  11. Effects of roof and rainwater characteristics on copper concentrations in roof runoff.

    Science.gov (United States)

    Bielmyer, Gretchen K; Arnold, W Ray; Tomasso, Joseph R; Isely, Jeff J; Klaine, Stephen J

    2012-05-01

    Copper sheeting is a common roofing material used in many parts of the world. However, copper dissolved from roof sheeting represents a source of copper ions to watersheds. Researchers have studied and recently developed a simple and efficient model to predict copper runoff rates. Important input parameters include precipitation amount, rain pH, and roof angle. We hypothesized that the length of a roof also positively correlates with copper concentration (thus, runoff rates) on the basis that runoff concentrations should positively correlate with contact time between acidic rain and the copper sheet. In this study, a novel system was designed to test and model the effects of roof length (length of roof from crown to the drip edge) on runoff copper concentrations relative to rain pH and roof angle. The system consisted of a flat-bottom copper trough mounted on an apparatus that allowed run length and slope to be varied. Water of known chemistry was trickled down the trough at a constant rate and sampled at the bottom. Consistent with other studies, as pH of the synthetic rainwater decreased, runoff copper concentrations increased. At all pH values tested, these results indicated that run length was more important in explaining variability in copper concentrations than was the roof slope. The regression equation with log-transformed data (R(2) = 0.873) accounted for slightly more variability than the equation with untransformed data (R(2) = 0.834). In log-transformed data, roof angle was not significant in predicting copper concentrations.

  12. Green Roofs for Stormwater Runoff Control - Abstract

    Science.gov (United States)

    This project evaluated green roofs as a stormwater management tool. Specifically, runoff quantity and quality from green and flat asphalt roofs were compared. Evapotranspiration from planted green roofs and evaporation from unplanted media roofs were also compared. The influence...

  13. Photovoltaic roofing tile systems

    Science.gov (United States)

    Melchior, B.

    The integration of photovoltaic (PV) systems in architecture is discussed. A PV-solar roofing tile system with polymer concrete base; PV-roofing tile with elastomer frame profiles and aluminum profile frames; contact technique; and solar cell modules measuring technique are described. Field tests at several places were conducted on the solar generator, electric current behavior, battery station, electric installation, power conditioner, solar measuring system with magnetic bubble memory technique, data transmission via telephone modems, and data processing system. The very favorable response to the PV-compact system proves the commercial possibilities of photovoltaic integration in architecture.

  14. 40 CFR 65.44 - External floating roof (EFR).

    Science.gov (United States)

    2010-07-01

    ... they are closed. (iii) Except for automatic bleeder vents, rim space vents, roof drains, and leg... and rim space vents shall be equipped with a gasket. (v) Each roof drain that empties into the stored... shall be designed to extend into the stored liquid and the other end shall extend a minimum vertical...

  15. Integrated roof wind energy system

    Directory of Open Access Journals (Sweden)

    Moonen S.P.G.

    2012-10-01

    Full Text Available Wind is an attractive renewable source of energy. Recent innovations in research and design have reduced to a few alternatives with limited impact on residential construction. Cost effective solutions have been found at larger scale, but storage and delivery of energy to the actual location it is used, remain a critical issue. The Integrated Roof Wind Energy System is designed to overcome the current issues of urban and larger scale renewable energy system. The system is built up by an axial array of skewed shaped funnels that make use of the Venturi Effect to accelerate the wind flow. This inventive use of shape and geometry leads to a converging air capturing inlet to create high wind mass flow and velocity toward a vertical-axis wind turbine in the top of the roof for generation of a relatively high amount of energy. The methods used in this overview of studies include an array of tools from analytical modelling, PIV wind tunnel testing, and CFD simulation studies. The results define the main design parameters for an efficient system, and show the potential for the generation of high amounts of renewable energy with a novel and effective system suited for the built environment.

  16. A green roof grant program for Washington DC

    International Nuclear Information System (INIS)

    Johnson, P.A.

    2007-01-01

    The Chesapeake Bay Foundation (CBF) began its green roof demonstration project with $300,000 in funding provided by the DC Water and Sewer Authority. This paper reviewed the history of the project, its goals and early findings. The main objective was to demonstrate the technical, policy and economic feasibility of installing green roofs on commercial buildings in Washington DC and to promote green roofs as a means to manage storm water and improve water quality through the reduction of excessive runoff. The CBF has issued grants for the installation of 7 green roofs varying in size, design, location, and use. The projects included both new and existing structures designed to improve storm-water management in an urban area with significant pollution stress on the adjacent rivers. This paper provided technical, cost, and performance evaluations of each roof. A public outreach segment provided information to decision-makers to encourage more widespread replication of green roof technology throughout the metropolitan area. Much of the District of Columbia is served by a combined sewer system that becomes overloaded and discharges raw sewage into adjacent rivers during even moderately heavy rains. An average of 75 overflow events each year result in 1.5 billion gallons discharged into the Anacostia River. The installation of green roofs on buildings in the combined sewer area would retain storm water during these heavy rains and reduce the amount of overflow discharges. Apartments, as well as commercial and government buildings with mostly flat roofs are the most likely candidates for green roofs. The demonstration roofs are intended to become models, which all building owners could use as a guide for future plans for construction or re-construction to expand green roof coverage in Washington DC. It was emphasized that although such large-scale replication will take time and financial investments, it is achievable given enough political will and commercial awareness of

  17. Sloshing impact in roofed tanks

    International Nuclear Information System (INIS)

    Uras, R.A.

    1995-01-01

    A large number of high-level waste (HLW) storage tanks exists in various tank farms. Seismic activities at those locations may cause significant sloshing in HLW tanks. These tanks are covered to avoid any spilling during large amplitude earthquakes. However, large amplitude sloshing may result in impact on the cover or the roof of the tank. Hence, a better understanding of the impact phenomenon is necessary to assess the safety of the tanks currently in existence, and to establish design guidelines for future designs. A pressure based formulation is derived to model sloshing impact in roofed tanks. It is incorporated into Argonne's in-house finite element code FLUSTR-ANL. A numerical test case with a harmonic input excitation is studied. The simulation results indicate that linear behavior is preserved beyond the first impact, and some mesh distortion is observed following a stronger second impact. During the impact, the displacement of the contacting surface nodes remains constant, and the velocities are reduced to zero. An identification of impacting nodes is possible from the dynamic pressures induced in surface elements

  18. Ecological Impacts of Replacing Traditional Roofs with Green Roofs in Two Urban Areas

    Directory of Open Access Journals (Sweden)

    Timothy Carter

    2008-01-01

    Full Text Available Urban land cover is dominated by impervious surface that degrades both terrestrial and aquatic ecosystems relative to predevelopment conditions. There are significant opportunities for designers of urban landscapes to use alternative land covers that have multiple functions, benefiting both human and nonhuman components of the urban ecosystem. Vegetated (green roofs are one form of alternative land cover that has shown the potential to provide a variety of ecological benefits in urban areas. We evaluated how stormwater retention, building energy and temperature, and rooftop habitat are influenced by the use of green roofs using test plots in Georgia and Massachusetts. Green roofs were shown to recreate part of the predevelopment hydrology through increasing interception, stormwater storage, evaporation, and transpiration on the rooftop and worked extremely well for small storm events. Temperature reductions were found on the green rooftop as compared to an asphalt surface, although other roof technologies that minimize temperatures, such as lighter colored membranes, provide similar benefits. Novel habitat was created on the rooftop, although the extent of this habitat was limited in part by plant survivability and the need for additional water inputs for diverse plant communities to survive. Despite the challenges, the green roof benefits reported here suggest that green roofs can be used effectively as a multifunctional land cover in urban areas.

  19. Solar radiation on domed roofs

    Energy Technology Data Exchange (ETDEWEB)

    Faghih, Ahmadreza K.; Bahadori, Mehdi N. [School of Mechanical Engineering, Sharif University of Technology, Tehran (Iran)

    2009-11-15

    Solar radiation received and absorbed by four domed roofs was estimated and compared with that of a flat roof. The domed roofs all had the same base areas, and equal to that of the flat roof. One of the roofs considered was the dome of the St. Peter's Church in Rome. Compared with the other roofs considered, this dome had a higher aspect ratio. It was found that all domed roofs received more solar radiation than the flat roof. Considering glazed tiles to cover a selected dome in Iran and the dome of the St. Peter's Church, it was found that the solar radiation absorbed by these roofs is reduced appreciably. In the case of the dome of St. Peter's Church, the amount of radiation absorbed was roughly equal to that absorbed by the comparable flat roof in the warm months. In the case of the glazed reference dome located in Yazd, Iran (a city with very high solar radiation), the radiation absorbed was less than that of flat roof at all times. In addition to aesthetics, this may be a reason for employing glazed tiles to cover the domes of all mosques, shrines, and other large buildings in Iran. (author)

  20. Green roof hydrologic performance and modeling: a review.

    Science.gov (United States)

    Li, Yanling; Babcock, Roger W

    2014-01-01

    Green roofs reduce runoff from impervious surfaces in urban development. This paper reviews the technical literature on green roof hydrology. Laboratory experiments and field measurements have shown that green roofs can reduce stormwater runoff volume by 30 to 86%, reduce peak flow rate by 22 to 93% and delay the peak flow by 0 to 30 min and thereby decrease pollution, flooding and erosion during precipitation events. However, the effectiveness can vary substantially due to design characteristics making performance predictions difficult. Evaluation of the most recently published study findings indicates that the major factors affecting green roof hydrology are precipitation volume, precipitation dynamics, antecedent conditions, growth medium, plant species, and roof slope. This paper also evaluates the computer models commonly used to simulate hydrologic processes for green roofs, including stormwater management model, soil water atmosphere and plant, SWMS-2D, HYDRUS, and other models that are shown to be effective for predicting precipitation response and economic benefits. The review findings indicate that green roofs are effective for reduction of runoff volume and peak flow, and delay of peak flow, however, no tool or model is available to predict expected performance for any given anticipated system based on design parameters that directly affect green roof hydrology.

  1. Structural assessment of roof decking using visual inspection methods

    International Nuclear Information System (INIS)

    Giller, R.A.; McCoy, R.M.; Wagenblast, G.R.

    1993-01-01

    The Hanford Site has approximately 1,100 buildings, some of which date back to the early 1940s. The roof on these buildings provides a weather resisting cover as well as the load resisting structure. Past experience has been that these roof structures may have structural modifications, the weather resisting membrane may have been replaced several times, and the members may experience some type of material degradation. This material degradation has progressed to cause the collapse of some roof deck members. The intent of the Hanford Site Central Engineering roof assessment effort is to provide an expedient structural assessment of the large number of buildings at the Hanford Site. This assessment is made by qualified structural inspectors following the open-quotes Preliminary Assessmentclose quotes procedures given in the American Society of Civil Engineers (ASCE) Standard ASCE 11-90. This roof assessment effort does not provide a total qualification of the roof for the design or in-place loads. This inspection does provide a reasonable estimate of the roof loading capacity to determine if personnel access restrictions are needed. A document search and a visual walkdown inspection provide the initial screening to identify modifications and components having questionable structural integrity. The structural assessment consists of baseline dead and live load stress calculations of all roofing components based on original design material strengths. The results of these assessments are documented in a final report which is retrievable in a form that future inspections will have comparative information

  2. Structural assessment of roof decking using visual inspection methods

    International Nuclear Information System (INIS)

    Giller, R.A.; McCoy, R.M.; Wagenblast, G.R.

    1993-10-01

    The Hanford Site has approximately 1,100 buildings, some of which date back to the early 1940s. The roof on these buildings provides a weather resisting cover as well as the load resisting structure. Past experience has been that these roof structures may have structural modifications, the weather resisting membrane may have been replaced several times, and the members may experience some type of material degradation. This material degradation has progressed to cause the collapse of some roof deck members. The intent of the Hanford Site Central Engineering roof assessment effort is to provide an expedient structural assessment of the large number of buildings at the Hanford Site. This assessment is made by qualified structural inspectors following the open-quotes Preliminary Assessment close-quote procedures given in the American Society of Civil Engineers (ASCE) Standard ASCE 11-90. This roof assessment effort does not provide a total qualification of the roof for the design or in-place loads. This inspection does provide a reasonable estimate of the roof loading capacity to determine if personnel access restrictions are needed. A document search and a visual walkdown inspection provide the initial screening to identify modifications and components having questionable structural integrity. The structural assessment consists of baseline dead and live load stress calculations of all roofing components based on original design material strengths. The results of these assessments are documented in a final report which is retrievable form that future inspections will have comparative information

  3. Comparing wildlife habitat and biodiversity across green roof type

    Energy Technology Data Exchange (ETDEWEB)

    Coffman, R.R. [Oklahoma Univ., Tulsa, OK (United States). Dept. of Landscape Architecture

    2007-07-01

    Green roofs represent restorative practices within human dominated ecosystems. They create habitat, increase local biodiversity, and restore ecosystem function. Cities are now promoting this technology as a part of mitigation for the loss of local habitat, making the green roof necessary in sustainable development. While most green roofs create some form of habitat for local and migratory fauna, some systems are designed to provide specific habitat for species of concern. Despite this, little is actually known about the wildlife communities inhabiting green roofs. Only a few studies have provided broad taxa descriptions across a range of green roof habitats, and none have attempted to measure the biodiversity across green roof class. Therefore, this study examined two different vegetated roof systems representative of North America. They were constructed under alternative priorities such as energy, stormwater and aesthetics. The wildlife community appears to be a result of the green roof's physical composition. Wildlife community composition and biodiversity is expected be different yet comparable between the two general types of green roofs, known as extensive and intensive. This study recorded the community composition found in the two classes of ecoroofs and assessed biodiversity and similarity at the community and group taxa levels of insects, spiders and birds. Renyi family of diversity indices were used to compare the communities. They were further described through indices and ratios such as Shannon's, Simpson's, Sorenson and Morsita's. In general, community biodiversity was found to be slightly higher in the intensive green roof than the extensive green roof. 26 refs., 4 tabs., 4 figs.

  4. Design and performance of B4WarmED, an aboveground and belowground free-air warming experiment at the temperate-boreal forest ecotone

    Science.gov (United States)

    Conducting manipulative climate change experiments in forests is challenging, given their spatial heterogeneity and canopy complexity. One specific challenge involves warming both plants and soils to depth in ecosystems without much bare ground. We describe the design, implementation, and performanc...

  5. Linking aboveground and belowground inducible plant resistance

    NARCIS (Netherlands)

    Bezemer, T.M.

    2009-01-01

    Induced resistance of plants against pests and diseases via plant defense responses is well documented and can occur aboveground, in the leaves, and belowground in the roots. A number of recent studies have shown that soil-borne pests can also induce plant resistance aboveground and vice versa.

  6. Hinged roof timber

    Energy Technology Data Exchange (ETDEWEB)

    Shestov, P I; Golub, A G; Yefremov, V I

    1980-08-07

    A hinged roof timer is suggested which includes a beam with prong and loop on the end which have openings in the form of ring slits for the distance wedges and round for the pins. In this case the opening of the distance wedge in the ring is arranged in relation to the opening for the pin closer to the end of the beam, and in the prong, in the opposite order. In order to improve the operating quality by guaranteeing active support of the cantilever roof timber without increasing its overall dimensions for the height of the opening for the distance wedge in the prong and the ring, beams are arranged axisymmetrically to the longitudinal axis.

  7. Historic timber roof structures

    OpenAIRE

    Magina, Miguel Jorge

    2013-01-01

    Dissertação para obtenção do Grau de Mestre em Engenharia Civil – Estruturas e Geotecnia This dissertation covers the study of historic timber roof structures in Transylvania area - Romania, the structures type, its elements and connection variety between them. Procedures to study a structure of this category are approached. It is also referred semi and non-destructive tests that can be done to better understand the present wood characteristics, and potential reparation or strengthening...

  8. Producing superhydrophobic roof tiles

    International Nuclear Information System (INIS)

    Carrascosa, Luis A M; Facio, Dario S; Mosquera, Maria J

    2016-01-01

    Superhydrophobic materials can find promising applications in the field of building. However, their application has been very limited because the synthesis routes involve tedious processes, preventing large-scale application. A second drawback is related to their short-term life under outdoor conditions. A simple and low-cost synthesis route for producing superhydrophobic surfaces on building materials is developed and their effectiveness and their durability on clay roof tiles are evaluated. Specifically, an organic–inorganic hybrid gel containing silica nanoparticles is produced. The nanoparticles create a densely packed coating on the roof tile surface in which air is trapped. This roughness produces a Cassie–Baxter regime, promoting superhydrophobicity. A surfactant, n-octylamine, was also added to the starting sol to catalyze the sol–gel process and to coarsen the pore structure of the gel network, preventing cracking. The application of ultrasound obviates the need to use volatile organic compounds in the synthesis, thereby making a ‘green’ product. It was also demonstrated that a co-condensation process effective between the organic and inorganic species is crucial to obtain durable and effective coatings. After an aging test, high hydrophobicity was maintained and water absorption was completely prevented for the roof tile samples under study. However, a transition from a Cassie–Baxter to a Wenzel state regime was observed as a consequence of the increase in the distance between the roughness pitches produced by the aging of the coating. (paper)

  9. Green roof systems: a study of public attitudes and preferences in southern Spain.

    Science.gov (United States)

    Fernandez-Cañero, Rafael; Emilsson, Tobias; Fernandez-Barba, Carolina; Herrera Machuca, Miguel Ángel

    2013-10-15

    This study investigates people's preconceptions of green roofs and their visual preference for different green roof design alternatives in relation to behavioral, social and demographical variables. The investigation was performed as a visual preference study using digital images created to represent eight different alternatives: gravel roof, extensive green roof with Sedums not in flower, extensive green roof with sedums in bloom, semi-intensive green roof with sedums and ornamental grasses, semi-intensive green roof with shrubs, intensive green roof planted with a lawn, intensive green roof with succulent and trees and intensive green roof with shrubs and trees. Using a Likert-type scale, 450 respondents were asked to indicate their preference for each digital image. Results indicated that respondents' sociodemographic characteristics and childhood environmental background influenced their preferences toward different green roof types. Results also showed that green roofs with a more careful design, greater variety of vegetation structure, and more variety of colors were preferred over alternatives. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Green roofs: roof system reducing heating and cooling costs

    Directory of Open Access Journals (Sweden)

    Konasova, Sarka

    2016-06-01

    Full Text Available Green roofs are among the passive building systems that contribute to the thermal stability of the rooms under the roof in both summer and winter. Green roofs can provide a significant contribution to the thermal balance of the protected space. Over the past ten years, many studies have been carried out to investigate the energy benefits of green roofs in terms of the energy performance of buildings. These studies show that the installation of vegetated cover can achieve energy savings for both winter heating and summer cooling. The green roof, as a thermal insulation, reduces the amount of building operating energy costs and reduces heat losses. This article summarizes current literature and points to situations in which green roofs can play an important role in saving energy for heating and cooling due to improved thermal insulating function of the roof, in case of extensive vegetation coverage without significant overloading of the roof structure and associated over-dimensioning. It is important to note that these energy savings always depend on the particular climate, the type of building and the availability and the type of roof structure.

  11. Analysis of the impact of thermal resistance of the roof on the performance of photovoltaic roof tiles

    Directory of Open Access Journals (Sweden)

    Kurz Dariusz

    2017-01-01

    Full Text Available The paper explores the issues related to the impact of thermal resistance of the roof on the electrical parameters of photovoltaic roof tiles. The methodology of determination of the thermal resistance and thermal transmittance factor was presented in accordance with the applicable legal regulations and standards. A test station was presented for the purpose of measurement of the parameters of photovoltaic roof tiles depending on the structure of the roof substrate. Detailed analysis of selected building components as well as their impact on the design thermal resistance factor and thermal transmittance factor was carried out. Results of our own studies, which indicated a relation between the type of the roof structure and the values of the electricity generated by photovoltaic tiles, were presented. Based on the calculations, it was concluded that the generated outputs in the respective constructions differ by maximum 6%. For cells with the highest temperature, the performance of the PV roof tiles on the respective roof constructions fell within the range between 0.4% and 1.2% (depending on the conducted measurement and amounted to 8.76% (in reference to 9.97% for roof tiles with the lowest temperature.

  12. Typology of Retractable Roof Structures in Stadiums and Sports Halls

    Directory of Open Access Journals (Sweden)

    Andrej Mahovič

    2015-10-01

    Full Text Available Retractable roof structures are one of the four fundamental systems (in addition to the playing area, stands and facade in a stadium and sports hall. The roof protects users against various weather conditions and creates optimum circumstances for carrying out different activities. Stadiums and sports halls with retractable roof structures can host a greater variety of activities, improve the quality of their implementation and the quality of visitors’ experience, and affect the perception and experience of people using or observing such buildings. A retractable roof structure allows for natural lighting and ventilation of the venue, gives optimal conditions for grass growth on the playing field, and reduces costs of use and maintenance of the building. Different typologies of movement of roof structures (frequency of opening and closing, design of the structure, and methods of movement are categorised in terms of their architectural and structural design. Application of different retractable roof systems worldwide is indicator of their effectiveness and efficiency, and is basis for use of movement also in other fundamental systems of stadiums and sports halls. Research and identification of characteristics of retractable roof structures lead to the design of new moving systems that can with the application of the moving principle change the purpose of movable elements or assume the characteristics of other fundamental systems.

  13. 30 CFR 75.205 - Installation of roof support using mining machines with integral roof bolters.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Installation of roof support using mining... Roof Support § 75.205 Installation of roof support using mining machines with integral roof bolters. When roof bolts are installed by a continuous mining machine with intregal roof bolting equipment: (a...

  14. Nontraumatic orbital roof encephalocele.

    Science.gov (United States)

    Hoang, Amber; Maugans, Todd; Ngo, Thang; Ikeda, Jamie

    2017-02-01

    Intraorbital meningoencephaloceles occur most commonly as a complication of traumatic orbital roof fractures. Nontraumatic congenital orbital meningoncephaloceles are very rare, with most secondary to destructive processes affecting the orbit and primary skull defects. Treatment for intraorbital meningoencephaloceles is surgical repair, involving the excision of herniated brain parenchyma and meninges and reconstruction of the osseous defect. Most congenital lesions present in infancy with obvious globe and orbital deformities; we report an orbital meningoencephalocele in a 3-year-old girl who presented with ptosis. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  15. The “shape” and “meaning” of the roof arts in Chinese classical architecture

    Science.gov (United States)

    Li, Xianda; liu, Yu

    2017-04-01

    This paper takes the “roof” in Chinese classical architecture as the research object. The breakthrough point of this paper would be the perspective of design aesthetics. Through the rational and perceptual analysis of the roof art, this paper would reveal that the roof shape has the double artistic features: “beauty of shape” and “beauty of idea”. This paper would have a comprehensive analysis for the following aspects: the rational method of roof construction, the emotional feeling of the roof construction and the implied meaning of beauty in the roof construction.

  16. Accidents due to falls from roof slabs.

    Science.gov (United States)

    Rudelli, Bruno Alves; Silva, Marcelo Valerio Alabarce da; Akkari, Miguel; Santili, Claudio

    2013-01-01

    CONTEXT AND OBJECTIVE Falls from the roof slabs of houses are accidents of high potential severity that occur in large Brazilian cities and often affect children and adolescents. The aims of this study were to characterize the factors that predispose towards this type of fall involving children and adolescents, quantify the severity of associated lesions and suggest preventive measures. DESIGN AND SETTING Descriptive observational prospective longitudinal study in two hospitals in the metropolitan region of São Paulo. METHODS Data were collected from 29 cases of falls from roof slabs involving children and adolescents between October 2008 and October 2009. RESULTS Cases involving males were more prevalent, accounting for 84%. The predominant age group was schoolchildren (7 to 12 years old; 44%). Leisure activities were most frequently being practiced on the roof slab at the time of the fall (86%), and flying a kite was the most prevalent game (37.9%). In 72% of the cases, the children were unaccompanied by an adult responsible for them. Severe conditions such as multiple trauma and traumatic brain injuries resulted from 79% of the accidents. CONCLUSION Falls from roof slabs are accidents of high potential severity, and preventive measures aimed towards informing parents and guardians about the dangers and risk factors associated with this type of accident are needed, along with physical protective measures, such as low walls around the slab and gates with locks to restrict free access to these places.

  17. Accidents due to falls from roof slabs

    Directory of Open Access Journals (Sweden)

    Bruno Alves Rudelli

    Full Text Available CONTEXT AND OBJECTIVE Falls from the roof slabs of houses are accidents of high potential severity that occur in large Brazilian cities and often affect children and adolescents. The aims of this study were to characterize the factors that predispose towards this type of fall involving children and adolescents, quantify the severity of associated lesions and suggest preventive measures. DESIGN AND SETTING Descriptive observational prospective longitudinal study in two hospitals in the metropolitan region of São Paulo. METHODS Data were collected from 29 cases of falls from roof slabs involving children and adolescents between October 2008 and October 2009. RESULTS Cases involving males were more prevalent, accounting for 84%. The predominant age group was schoolchildren (7 to 12 years old; 44%. Leisure activities were most frequently being practiced on the roof slab at the time of the fall (86%, and flying a kite was the most prevalent game (37.9%. In 72% of the cases, the children were unaccompanied by an adult responsible for them. Severe conditions such as multiple trauma and traumatic brain injuries resulted from 79% of the accidents. CONCLUSION Falls from roof slabs are accidents of high potential severity, and preventive measures aimed towards informing parents and guardians about the dangers and risk factors associated with this type of accident are needed, along with physical protective measures, such as low walls around the slab and gates with locks to restrict free access to these places.

  18. Quantitative analysis on the urban flood mitigation effect by the extensive green roof system

    International Nuclear Information System (INIS)

    Lee, J.Y.; Moon, H.J.; Kim, T.I.; Kim, H.W.; Han, M.Y.

    2013-01-01

    Extensive green-roof systems are expected to have a synergetic effect in mitigating urban runoff, decreasing temperature and supplying water to a building. Mitigation of runoff through rainwater retention requires the effective design of a green-roof catchment. This study identified how to improve building runoff mitigation through quantitative analysis of an extensive green-roof system. Quantitative analysis of green-roof runoff characteristics indicated that the extensive green roof has a high water-retaining capacity response to rainfall of less than 20 mm/h. As the rainfall intensity increased, the water-retaining capacity decreased. The catchment efficiency of an extensive green roof ranged from 0.44 to 0.52, indicating reduced runoff comparing with efficiency of 0.9 for a concrete roof. Therefore, extensive green roofs are an effective storm water best-management practice and the proposed parameters can be applied to an algorithm for rainwater-harvesting tank design. -- Highlights: •Urban extensive green roof systems have a synergetic effect in mitigating urban runoff. •These systems are improve runoff mitigation and decentralized urban water management. •These systems have a high water-retaining capacity response to rainfall of less than 20 mm/h. •The catchment efficiency of an extensive green roof ranged from 0.44 to 0.52. -- Extensive green-roofs are an effective storm water best-management practice and the proposed parameters can be applied to mitigate urban runoff

  19. Experimental effects of herbivore density on above-ground plant biomass in an alpine grassland ecosystem

    OpenAIRE

    Austrheim, Gunnar; Speed, James David Mervyn; Martinsen, Vegard; Mulder, Jan; Mysterud, Atle

    2014-01-01

    Herbivores may increase or decrease aboveground plant productivity depending on factors such as herbivore density and habitat productivity. The grazing optimization hypothesis predicts a peak in plant production at intermediate herbivore densities, but has rarely been tested experimentally in an alpine field setting. In an experimental design with three densities of sheep (high, low, and no sheep), we harvested aboveground plant biomass in alpine grasslands prior to treatment and after five y...

  20. Green roofs for a drier world: effects of hydrogel amendment on substrate and plant water status.

    Science.gov (United States)

    Savi, Tadeja; Marin, Maria; Boldrin, David; Incerti, Guido; Andri, Sergio; Nardini, Andrea

    2014-08-15

    Climate features of the Mediterranean area make plant survival over green roofs challenging, thus calling for research work to improve water holding capacities of green roof systems. We assessed the effects of polymer hydrogel amendment on the water holding capacity of a green roof substrate, as well as on water status and growth of Salvia officinalis. Plants were grown in green roof experimental modules containing 8 cm or 12 cm deep substrate (control) or substrate mixed with hydrogel at two different concentrations: 0.3 or 0.6%. Hydrogel significantly increased the substrate's water content at saturation, as well as water available to vegetation. Plants grown in 8 cm deep substrate mixed with 0.6% of hydrogel showed the best performance in terms of water status and membrane integrity under drought stress, associated to the lowest above-ground biomass. Our results provide experimental evidence that polymer hydrogel amendments enhance water supply to vegetation at the establishment phase of a green roof. In particular, the water status of plants is most effectively improved when reduced substrate depths are used to limit the biomass accumulation during early growth stages. A significant loss of water holding capacity of substrate-hydrogel blends was observed after 5 months from establishment of the experimental modules. We suggest that cross-optimization of physical-chemical characteristics of hydrogels and green roof substrates is needed to improve long term effectiveness of polymer-hydrogel blends. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Multi functional roof structures of the energy efficient buildings

    Directory of Open Access Journals (Sweden)

    Krstić Aleksandra

    2006-01-01

    Full Text Available Modern architectural concepts, which are based on rational energy consumption of buildings and the use of solar energy as a renewable energy source, give the new and significant role to the roofs that become multifunctional structures. Various energy efficient roof structures and elements, beside the role of protection, provide thermal and electric energy supply, natural ventilation and cooling of a building, natural lighting of the indoor space sunbeam protection, water supply for technical use, thus according to the above mentioned functions, classification and analysis of such roof structures and elements are made in this paper. The search for new architectural values and optimization in total energy balance of a building or the likewise for the urban complex, gave to roofs the role of "climatic membranes". Contemporary roof forms and materials clearly exemplify their multifunctional features. There are numerous possibilities to achieve the new and attractive roof design which broadens to the whole construction. With such inducement, this paper principally analyze the configuration characteristics of the energy efficient roof structures and elements, as well as the visual effects that may be achieved by their application.

  2. Field Testing of an Unvented Roof with Fibrous Insulation, Tiles, and Vapor Diffusion Venting

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, K. [Building Science Corporation, Westford, MA (United States); Lstiburek, J. W. [Building Science Corporation, Westford, MA (United States)

    2016-02-01

    This research is a test implementation of an unvented tile roof assembly in a hot-humid climate (Orlando, FL; Zone 2A), insulated with air permeable insulation (netted and blown fiberglass). Given the localized moisture accumulation and failures seen in previous unvented roof field work, it was theorized that a 'diffusion vent' (water vapor open, but air barrier 'closed') at the highest points in the roof assembly might allow for the wintertime release of moisture, to safe levels. The 'diffusion vent' is an open slot at the ridge and hips, covered with a water-resistant but vapor open (500+ perm) air barrier membrane. As a control comparison, one portion of the roof was constructed as a typical unvented roof (self-adhered membrane at ridge). The data collected to date indicate that the diffusion vent roof shows greater moisture safety than the conventional, unvented roof design.

  3. Energy roofs. Energiedaken

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    Low grade heat from roofs and walls can be upgraded to useful temperatures by heat pumps. Even latent heat can be used. This report gives a survey of the possibilities to use these forms of heat in houses. Several types of heat pumps are described; working of heat absorbers is explained and cost aspects are discussed. Absorbers are less sensitive for shadows than solar collectors, which is a remarkable advantage in urban areas where high-rise building is employed. Application of solar absorbers is closely connected to heat pumps. Both absorber systems and heat pumps are so expensive that the costs are now prohibitive when gas is available, but this is due to small production series. Construction and materials make cheaper production possible when demand increases. (A.V.)

  4. An eye for the green top : an independent voice for green roofs in the UK

    Energy Technology Data Exchange (ETDEWEB)

    Frith, M.; Gedge, D. [Livingroofs.org, England (United Kingdom)

    2005-07-01

    Livingroofs.org is a non-profit organization that was established to provide a resource for promoting green roofs in the United Kingdom (UK). Current policies in the UK related to the planning and development of green roofs are a constraint to their uptake. The emerging emphasis on sustainable development is bringing about a revision of planning policies that may make green roofs more desirable. However, green roof design standards are still being developed by a largely unmonitored industry furthering a product with which most people are unfamiliar. This paper reviewed a number of issues that need to be addressed to assist in the wider adoption of green roofs, including increased awareness; an identification of the real benefits of green roofs; guidance and research; planning policies; fiscal incentives; industry standards and codes of practice. Details of the current policy frameworks for construction, urban design and climate change were also outlined. Two specific projects were reviewed to provide an insight into the way in which Livingroofs.org intends to promote green roof technology: a roof owned by the Birmingham city council and a collaboration with a Swiss partner to design a roof for the Komodo Dragon House at the London Zoo. It was concluded that there is now a real likelihood that the widespread adoption of green roofs will occur in the UK within the next 5 years, both in terms of new developments and the vast potential for retro-fitting on existing buildings. 47 refs., 2 tabs.

  5. Evaluation of the Lateral Performance of Roof Truss-to-Wall Connections in Light-Frame Wood Systems

    Science.gov (United States)

    Andrew DeRenzis; Vladimir Kochkin; Xiping Wang

    2012-01-01

    This testing program was designed to benchmark the performance of traditional roof systems and incrementally improved roof-to-wall systems with the goal of developing connection solutions that are optimized for performance and constructability. Nine full-size roof systems were constructed and tested with various levels and types of heel detailing to measure the lateral...

  6. Total heat loss coefficient of flat roof constructions with external insulation in tapered layers including the effects of thermal bridges

    DEFF Research Database (Denmark)

    Rose, Jørgen; Svendsen, Svend

    2005-01-01

    In order to achieve durability of flat roofs with external insulation, it is necessary to secure proper drainage of the roof, i.e. to avoid water leaking into the insulation. The design of the tapered insulation of the roof is quite difficult as requirements with respect to both drainage...

  7. The properties degradation of exposed GFRP roof

    Science.gov (United States)

    Zainudin, Mohammad; Diharjo, Kuncoro; Kaavessina, Mujtahid; Setyanto, Djoko

    2018-02-01

    There is much consideration of roof selection as a protector of a building against the outside weather, such as lightweight, strong stiff, corrosion resistant and guarantee for the availability of products. Based on these considerations, glass fiber reinforced polymer (GFRP) roof is a roof which can fulfill the requirement. The objective of this research is to investigate the degradation of physical and mechanical properties of GFRP roof exposed in outside weather. This GFRP roof composite was produced using a sheet molding compound (SMC) supplied by PT Intec Persada, Tangerang, Indonesia. There are two kinds GFRP roofs evaluated in this research that are GFRP roof exposed within 7 years and new GFRP roof that has not been exposed. The GFRP roofs were cut manually for preparing the specimens for hardness test, tensile test, SEM and FTIR test. The results show that the GFRP roof exposed within 7 years had the degradation of properties compared to the new GFRP roof. The exposed GFRP roof had lower strength and hardness compared to the new GFRP roof. The SEM observation indicates that exposed GFRP roof had the debonding of fiber on the surface, and in contrast, there are no debonding of fiber in the new GFRP roof surface. It can be recommended that the exposed GFRP roof may be repaired to enhance its performance and can re-increase its properties using the coating.

  8. Green Roofs for Stormwater Runoff Control

    Science.gov (United States)

    This project evaluated green roofs as a stormwater management tool. Specifically, runoff quantity and quality from green and flat asphalt roofs were compared. Evapotranspiration from planted green roofs and evaporation from unplanted media roofs were also compared. The influence...

  9. 30 CFR 75.204 - Roof bolting.

    Science.gov (United States)

    2010-07-01

    ... accessories addressed in ASTM F432-95, “Standard Specification for Roof and Rock Bolts and Accessories,” the.... (4) In each roof bolting cycle, the actual torque or tension of the first tensioned roof bolt... during each roof bolting cycle shall be tested during or immediately after the first row of bolts has...

  10. Selection of powered roof support for weak coal roof

    Energy Technology Data Exchange (ETDEWEB)

    Ramayya, M.S.V.; Sudhakar, L. [Singareni Collieries Co. Ltd., Kothagudem (India)

    2002-04-01

    Singareni Collieries Company Ltd (SCCL) introduced mechanised longwall mining in 1983. The first few faces were worked with conventional and immediate forward supports (IFS), with capacities in the range of 360 to 450 t. These under capacity supports increased from abutment loads and there was breakage of roof in front of the supports which resulted in closure of powered roof supports, followed by face cavities. The cavities were more frequent and were difficult to negotiate especially in case of IFS supports. Subsequently, support capacity was increased at Padmavati Khani (PVK) mine and at GDK.10a and GKD.9LFP Inclines where the roof is composed of weak, coal, shale and clay. Problems related to failure of hydraulics/legs etc., which are repairable have occurred; though the problems are not totally eliminated, there was definite improvement in strata control with these higher capacity supports. Monitoring of supports was conducted all through the working of longwall panels. The data generated while working these longwall faces were analysed to study the suitability of other types of powered roof supports, namely 2 legged shield supports/4 legged supports for improved strata control. The analysis and practical experiences suggest that in weak, coaly, shale and clay roofs 2 legged shield supports offer better roof control. 4 refs., 4 figs.

  11. The effect of roofing material on the quality of harvested rainwater.

    Science.gov (United States)

    Mendez, Carolina B; Klenzendorf, J Brandon; Afshar, Brigit R; Simmons, Mark T; Barrett, Michael E; Kinney, Kerry A; Kirisits, Mary Jo

    2011-02-01

    Due to decreases in the availability and quality of traditional water resources, harvested rainwater is increasingly used for potable and non-potable purposes. In this study, we examined the effect of conventional roofing materials (i.e., asphalt fiberglass shingle, Galvalume(®) metal, and concrete tile) and alternative roofing materials (i.e., cool and green) on the quality of harvested rainwater. Results from pilot-scale and full-scale roofs demonstrated that rainwater harvested from any of these roofing materials would require treatment if the consumer wanted to meet United States Environmental Protection Agency primary and secondary drinking water standards or non-potable water reuse guidelines; at a minimum, first-flush diversion, filtration, and disinfection are recommended. Metal roofs are commonly recommended for rainwater harvesting applications, and this study showed that rainwater harvested from metal roofs tends to have lower concentrations of fecal indicator bacteria as compared to other roofing materials. However, concrete tile and cool roofs produced harvested rainwater quality similar to that from the metal roofs, indicating that these roofing materials also are suitable for rainwater harvesting applications. Although the shingle and green roofs produced water quality comparable in many respects to that from the other roofing materials, their dissolved organic carbon concentrations were very high (approximately one order of magnitude higher than what is typical for a finished drinking water in the United States), which might lead to high concentrations of disinfection byproducts after chlorination. Furthermore the concentrations of some metals (e.g., arsenic) in rainwater harvested from the green roof suggest that the quality of commercial growing media should be carefully examined if the harvested rainwater is being considered for domestic use. Hence, roofing material is an important consideration when designing a rainwater catchment. Copyright

  12. Green roofs and the LEED green building rating system

    Energy Technology Data Exchange (ETDEWEB)

    Kula, R. [Sustainable Solutions Inc., Wagoner, OK (United States)

    2005-07-01

    The sustainable building industry is becoming increasingly aware of the host of public and private benefits that green roofs can provide in built environments. In dense urban environments, green roofs function to reduce stormwater runoff, urban heat island effects, and particulate matter (PM) pollution. The emerging green roof industry is now poised to support the efforts of green building networks in North America. This paper discussed the general benefits of green roofs, and their recognition within the Leadership in Energy and Environmental Design (LEED) Green Building Rating System. A case study of Mountain Equipment Co-op's Winnipeg site was presented. The building's green roof was directly responsible for earning 5 credits and contributing to the achievement of an additional 2 credits under the LEEDS certification process. Credits were earned for reduced site disturbance; landscape design to reduce heat islands; and water efficiency. The green roof at the site provided the vast majority of the building's cooling needs through an evaporative cooling trough. A photovoltaic pump was used to feed the building's irrigation system, as well as to pump ground water through cooling valances. It was concluded that the rise of sustainable building practices and the LEED Green Building Rating System will revolutionize the way new buildings are constructed.

  13. Sloshing impact in roofed tanks

    International Nuclear Information System (INIS)

    Uras, R.A.

    1995-01-01

    A large number of high-level waste (HLW) storage tanks exists in various tank farms. Seismic activities at those locations may cause significant sloshing in HLW tanks. These tanks are covered to avoid any spilling during large amplitude earthquakes. However, large amplitude sloshing may result in impact on the cover or the roof of the tank. Hence, a better understanding of the impact phenomenon is necessary to assess the safety of the tanks currently in existence, and to establish design guidelines for future designs. A pressure based formulation is derived to model sloshing impact in roared tanks. It is incorporated into Argonne's in-house finite element code FLUSTR-ANL. A numerical test case with a harmonic input excitation is studied. The simulation results indicate that linear behavior is preserved beyond the first impact, and some mesh distortion is observed following a stronger second impact. During the impact, the displacement of the contacting surface nodes remains constant, and the velocities are reduced to zero. An identification of impacting nodes is possible from the dynamic pressures induced in surface elements

  14. The impact of roofing material on building energy performance

    Science.gov (United States)

    Badiee, Ali

    The last decade has seen an increase in the efficient use of energy sources such as water, electricity, and natural gas as well as a variety of roofing materials, in the heating and cooling of both residential and commercial infrastructure. Oil costs, coal and natural gas prices remain high and unstable. All of these instabilities and increased costs have resulted in higher heating and cooling costs, and engineers are making an effort to keep them under control by using energy efficient building materials. The building envelope (that which separates the indoor and outdoor environments of a building) plays a significant role in the rate of building energy consumption. An appropriate architectural design of a building envelope can considerably lower the energy consumption during hot summers and cold winters, resulting in reduced HVAC loads. Several building components (walls, roofs, fenestration, foundations, thermal insulation, external shading devices, thermal mass, etc.) make up this essential part of a building. However, thermal insulation of a building's rooftop is the most essential part of a building envelope in that it reduces the incoming "heat flux" (defined as the amount of heat transferred per unit area per unit time from or to a surface) (Sadineni et al., 2011). Moreover, more than 60% of heat transfer occurs through the roof regardless of weather, since a roof is often the building surface that receives the largest amount of solar radiation per square annually (Suman, and Srivastava, 2009). Hence, an argument can be made that the emphasis on building energy efficiency has influenced roofing manufacturing more than any other building envelope component. This research project will address roofing energy performance as the source of nearly 60% of the building heat transfer (Suman, and Srivastava, 2009). We will also rank different roofing materials in terms of their energy performance. Other parts of the building envelope such as walls, foundation

  15. ENERGY STAR Certified Roof Products

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Roof Products that are effective as of July 1,...

  16. Run-off from roofs

    International Nuclear Information System (INIS)

    Roed, J.

    1985-01-01

    In order to find the run-off from roof material a roof has been constructed with two different slopes (30 deg C and 45 deg C). Beryllium-7 and caesium-137 has been used as tracers. Considering new roof material the pollution removed by runoff processes has been shown to be very different for various roof materials. The pollution is much more easily removed from silicon-treated material than from porous red-tile roof material. Caesium is removed more easily than beryllium. The content of caesium in old roof materials is greater in red-tile than in other less-porous materials. However, the measured removal from new material does not correspond to the amount accumulated in the old. This could be explained by weathering and by saturation effects. This last effect is probably the more important. The measurements on old material indicates a removal of 44-86% of the caesium pollution by run-off, whereas the measurement on new showed a removal of only 31-50%. It has been demonstrated that the pollution concentration in the run-off water could be very different from that in rainwater. The work was part of the EEC Radiation Protection Programme and done under a subcontract with Association Euratom-C.E.A. No. SC-014-BIO-F-423-DK(SD) under contract No. BIO-F-423-81-F. (author)

  17. [A review of green roof performance towards management of roof runoff].

    Science.gov (United States)

    Chen, Xiao-ping; Huang, Pei; Zhou, Zhi-xiang; Gao, Chi

    2015-08-01

    Green roof has a significant influence on reducing runoff volume, delaying runoff-yielding time, reducing the peak flow and improving runoff quality. This paper addressed the related research around the world and concluded from several aspects, i.e., the definition of green roof of different types, the mechanism how green roof manages runoff quantity and quality, the ability how green roof controls roof runoff, and the influence factors of green roof toward runoff quantity and quality. Afterwards, there was a need for more future work on research of green roof toward roof runoff, i.e., vegetation selection of green roof, efficient construction model selection of green roof, the regulating characteristics of green roof on roof runoff, the value assessment of green roof on roof runoff, analysis of source-sink function of green roof on the water pollutants of roof runoff and the research on the mitigation measures of roof runoff pollution. This paper provided a guideline to develop green roofs aiming to regulating roof runoff.

  18. Green roofs and implementing the goals of Smart Growth

    International Nuclear Information System (INIS)

    Loder, A.; Peck, S.W.

    2004-01-01

    Smart Growth is a movement developed by city planners to counteract urban sprawl and inner-city deterioration. This paper explored the use of green roofs as a tangible means to attain the following 4 main goals of Smart Growth: (1) support infill development which refers to the concentration of development in already existing nodes and corridors served by public transit, (2) make cities more liveable, healthy, and environmentally sustainable, (3) create new green space and habitat for biodiversity preservation, and (4) support efficient and green infrastructure. It was suggested that few technologies provide such a wide range of opportunity as green roofs do to generate tangible social, economic and environmental benefits. Roof space represents 15 to 35 per cent of the total land area in a city. In addition to providing stormwater management, green roofs contribute to a reduction of the urban heat island, bringing nature back into the city. It was noted that generating new accessible and inaccessible green space is consistent with the needs and desires or urban dwellers. The extent to which green roofs can provide public benefits depends on the type of design. Green roofs not only cool the buildings they sit upon, but generate cooling for the surrounding area that can result in reduced energy consumption and improvements in air quality. 64 refs., 2 figs

  19. Measure Guideline. Deep Energy Enclosure Retrofit for Zero Energy Ready House Flat Roofs

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, H. [Building Science Corporation, Westford, MA (United States); Pettit, B. [Building Science Corporation, Westford, MA (United States)

    2015-05-29

    This Measure Guideline provides design and construction information for a deep energy enclosure retrofit solution of a flat roof assembly. It describes the strategies and procedures for an exterior retrofit of a flat wood-framed roof with brick masonry exterior walls using exterior and interior (framing cavity) insulation. The approach supported in this guide could also be adapted for use with flat wood-framed roofs with wood-framed exterior walls.

  20. Measure Guideline: Deep Energy Enclosure Retrofit for Zero Energy Ready House Flat Roofs

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, H. [Building Science Corporation, Westford, MA (United States); Pettit, B. [Building Science Corporation, Westford, MA (United States)

    2015-05-01

    This Measure Guideline provides design and construction information for a deep energy enclosure retrofit (DEER) solution of a flat roof assembly. It describes the strategies and procedures for an exterior retrofit of a flat, wood-framed roof with brick masonry exterior walls, using exterior and interior (framing cavity) insulation. The approach supported in this guide could also be adapted for use with flat, wood-framed roofs with wood-framed exterior walls.

  1. Impact of green roofs on stormwater quality in a South Australian urban environment.

    Science.gov (United States)

    Razzaghmanesh, M; Beecham, S; Kazemi, F

    2014-02-01

    Green roofs are an increasingly important component of water sensitive urban design systems and can potentially improve the quality of urban runoff. However, there is evidence that they can occasionally act as a source rather than a sink for pollutants. In this study, the water quality of the outflow from both intensive and extensive green roof systems were studied in the city of Adelaide, South Australia over a period of nine months. The aim was to examine the effects of different green roof configurations on stormwater quality and to compare this with runoff from aluminium and asphalt roofs as control surfaces. The contaminant concentrations in runoff from both intensive and extensive green roofs generally decreased during the study period. A comparison between the two types of green roof showed that except for some events for EC, TDS and chloride, the values of the parameters such as pH, turbidity, nitrate, phosphate and potassium in intensive green roof outflows were higher than in the outflows from the extensive green roofs. These concentrations were compared to local, state, national and international water quality guidelines in order to investigate the potential for outflow runoff from green roofs to be reused for potable and non-potable purposes. The study found that green roof outflow can provide an alternative water source for non-potable purposes such as urban landscape irrigation and toilet flushing. © 2013.

  2. Sheffield's Green Roof Forum: a multi-stranded programme of green roof infrastructure development for the UK's greenest city

    International Nuclear Information System (INIS)

    Dunnett, N.

    2006-01-01

    Sheffield, United Kingdom (UK) was the world centre for the steel and cutlery industries. However, those industries have been in decline and the city has been in the process of re-inventing itself over the past 20 years. Sheffield is now known as the UK's greenest city in terms of the amount of woodland, parkland and open spaces within its city limits. The city of Sheffield has also developed a unique partnership approach to promote green roof infrastructure as the most visible and high-profile signal of intent and symbol of low environmental impact building design and construction. This partnership involves Sheffield's Green Roof Forum, comprising the University of Sheffield's multi-disciplinary centre of excellence in green roof research; Sheffield City Council; Groundwork Sheffield, an urban economic and environmental regeneration agency; and city Architects and developers. This partnership meets six times a year to raise the profile of green roofs within the city and region, and to develop strategies to increase the uptake and implementation of green roof infrastructure in the region. This paper discussed the partnership, the Green Room Forum, accomplishments to date in promoting green roofs in the city, and the strategy for the Sheffield region to become a leader in green roof implementation and associated green technologies. The strategy is presented in two parts: consultation and research to identify the nature of market failure and devising methods to overcome that failure. The green roof strategy is being implemented through a program entitled Building Greener, Building Smarter and consists of four inter-linked strands. These strands were discussed in detail and included getting buy-in, demonstrating benefit, establishing the business case, and changing plans and practices. 3 tabs., 1 ref

  3. Building America Case Study: Field Testing an Unvented Roof with Fibrous Insulation and Tiles, Orlando, Florida

    Energy Technology Data Exchange (ETDEWEB)

    2015-11-01

    This research is a test implementation of an unvented tile roof assembly in a hot-humid climate (Orlando, FL; Zone 2A), insulated with air permeable insulation (netted and blown fiberglass). Given the localized moisture accumulation and failures seen in previous unvented roof field work, it was theorized that a 'diffusion vent' (water vapor open, but air barrier 'closed') at the highest points in the roof assembly might allow for the wintertime release of moisture, to safe levels. The 'diffusion vent' is an open slot at the ridge and hips, covered with a water-resistant but vapor open (500+ perm) air barrier membrane. As a control comparison, one portion of the roof was constructed as a typical unvented roof (self-adhered membrane at ridge). The data collected to date indicate that the diffusion vent roof shows greater moisture safety than the conventional, unvented roof design. The unvented roof had extended winter periods of 95-100% RH, and wafer (wood surrogate RH sensor) measurements indicating possible condensation; high moisture levels were concentrated at the roof ridge. In contrast, the diffusion vent roofs had drier conditions, with most peak MCs (sheathing) below 20%. In the spring, as outdoor temperatures warmed, all roofs dried well into the safe range (10% MC or less). Some roof-wall interfaces showed moderately high MCs; this might be due to moisture accumulation at the highest point in the lower attic, and/or shading of the roof by the adjacent second story. Monitoring will be continued at least through spring 2016 (another winter and spring).

  4. Field Testing of an Unvented Roof with Fibrous Insulation, Tiles and Vapor Diffusion Venting

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, K. [Building Science Corporation, Westford, MA (United States); Lstiburek, J. W. [Building Science Corporation, Westford, MA (United States)

    2016-02-05

    This research is a test implementation of an unvented tile roof assembly in a hot-humid climate (Orlando, FL; Zone 2A), insulated with air permeable insulation (netted and blown fiberglass). Given the localized moisture accumulation and failures seen in previous unvented roof field work, it was theorized that a 'diffusion vent' (water vapor open, but air barrier 'closed') at the highest points in the roof assembly might allow for the wintertime release of moisture, to safe levels. The 'diffusion vent' is an open slot at the ridge and hips, covered with a water-resistant but vapor open (500+ perm) air barrier membrane. As a control comparison, one portion of the roof was constructed as a typical unvented roof (self-adhered membrane at ridge). The data collected to date indicate that the diffusion vent roof shows greater moisture safety than the conventional, unvented roof design. The unvented roof had extended winter periods of 95-100% RH, and wafer (wood surrogate RH sensor) measurements indicating possible condensation; high moisture levels were concentrated at the roof ridge. In contrast, the diffusion vent roofs had drier conditions, with most peak MCs (sheathing) below 20%. In the spring, as outdoor temperatures warmed, all roofs dried well into the safe range (10% MC or less). Some roof-wall interfaces showed moderately high MCs; this might be due to moisture accumulation at the highest point in the lower attic, and/or shading of the roof by the adjacent second story. Monitoring will be continued at least through spring 2016 (another winter and spring).

  5. Developing resilient green roofs in a dry climate.

    Science.gov (United States)

    Razzaghmanesh, M; Beecham, S; Brien, C J

    2014-08-15

    Living roofs are an emerging green infrastructure technology that can potentially be used to ameliorate both climate change and urban heat island effects. There is not much information regarding the design of green roofs for dry climates and so the aim of this study was to develop low maintenance and unfertilized green roofs for a dry climate. This paper describes the effects of four important elements of green roofs namely slope, depth, growing media and plant species and their possible interactions in terms of plant growth responses in a dry climate. Sixteen medium-scale green roofs were set up and monitored during a one year period. This experiment consisted of twelve vegetated platforms and four non-vegetated platforms as controls. The design for the experiment was a split-split-plot design in which the factors Slope (1° and 25°) and Depth (100mm, 300 mm) were randomized to the platforms (main plots). Root depth and volume, average height of plants, final dry biomass and ground cover, relative growth rate, final dry shoot-root ratio, water use efficiency and leaf succulence were studied during a twelve month period. The results showed little growth of the plants in media type A, whilst the growth was significant in both media types B and C. On average, a 90% survival rate of plants was observed. Also the growth indices indicated that some plants can grow efficiently in the harsh environment created by green roofs in a dry climate. The root growth pattern showed that retained water in the drainage layer is an alternative source of water for plants. It was also shown that stormwater can be used as a source of irrigation water for green roofs during six months of the year at the study site. In summary, mild sloping intensive systems containing media type C and planted with either Chrysocephalum apiculatum or Disphyma crassifolium showed the best performance. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Ecological linkages between aboveground and belowground biota

    NARCIS (Netherlands)

    Wardle, D.A.; Bardgett, R.D.; Klironomos, J.N.; Setälä, H.; Putten, van der W.H.; Wall, D.H.

    2004-01-01

    All terrestrial ecosystems consist of aboveground and belowground components that interact to influence community- and ecosystem-level processes and properties. Here we show how these components are closely interlinked at the community level, reinforced by a greater degree of specificity between

  7. Plant species and functional group combinations affect green roof ecosystem functions.

    Science.gov (United States)

    Lundholm, Jeremy; Macivor, J Scott; Macdougall, Zachary; Ranalli, Melissa

    2010-03-12

    Green roofs perform ecosystem services such as summer roof temperature reduction and stormwater capture that directly contribute to lower building energy use and potential economic savings. These services are in turn related to ecosystem functions performed by the vegetation layer such as radiation reflection and transpiration, but little work has examined the role of plant species composition and diversity in improving these functions. We used a replicated modular extensive (shallow growing- medium) green roof system planted with monocultures or mixtures containing one, three or five life-forms, to quantify two ecosystem services: summer roof cooling and water capture. We also measured the related ecosystem properties/processes of albedo, evapotranspiration, and the mean and temporal variability of aboveground biomass over four months. Mixtures containing three or five life-form groups, simultaneously optimized several green roof ecosystem functions, outperforming monocultures and single life-form groups, but there was much variation in performance depending on which life-forms were present in the three life-form mixtures. Some mixtures outperformed the best monocultures for water capture, evapotranspiration, and an index combining both water capture and temperature reductions. Combinations of tall forbs, grasses and succulents simultaneously optimized a range of ecosystem performance measures, thus the main benefit of including all three groups was not to maximize any single process but to perform a variety of functions well. Ecosystem services from green roofs can be improved by planting certain life-form groups in combination, directly contributing to climate change mitigation and adaptation strategies. The strong performance by certain mixtures of life-forms, especially tall forbs, grasses and succulents, warrants further investigation into niche complementarity or facilitation as mechanisms governing biodiversity-ecosystem functioning relationships in green

  8. Single-sided natural ventilation through a centre-pivot roof window

    DEFF Research Database (Denmark)

    Iqbal, Ahsan; Nielsen, Peter V.; Gunner, Amalie

    2014-01-01

    The characteristics of centre pivot roof windows for wind driven single-sided ventilation has not been studied before. These types of windows are dominating roof windows in Europe. Knowledge of flow characteristics of this kind of window is essential for accurate designing of natural ventilation...... systems. In this study, numerical methods were used to characterise a centre-pivot roof window for wind-driven single-sided ventilation. A 1:20 scale model house of the Energy Flex House (Denmark) was used in this study. The roof slope was 36o. It was found that the single-sided ventilation through...

  9. Portland's experience with land use tools to promote green roofs

    International Nuclear Information System (INIS)

    Johnson, M.

    2004-01-01

    In the late 1990s, the City of Portland, Oregon faced environmental challenges that prompted the City to mandate environmentally sensitive development. Several programs were developed in response to these challenges, some of which resulted in the creation of land use policies and incentives that promote green roofs. Zoning code provisions were adopted in 2001 to promote eco-roofs in an effort to reduce stormwater runoff, mitigate urban heat island effects, provide habitat for birds, and improve air quality and energy efficiency. The Central City Fundamental Design Guidelines were also revised to encourage eco-roof development. In 2002, the South Waterfront Plan was created to integrate ecological design into an urban environment through sustainability principles and practices. Land use tools were developed to introduce developers to an approach that reduced energy costs and stormwater costs, while also contributing to a project's marketability. These tools were created with the support of programs and policies such as the CSO (Combined Sewer Overflow) Program; eco-roof research which began in 1995 to determine the stormwater management potential of eco-Green roofs; technical assistance to encourage and highlight sustainable development practices; the Stormwater Management Manual that set standards for the amount and quality of stormwater runoff leaving development sites; the G/Rated Program that offers resources for green building practices; the Green Investment Fund that supports the G/Rated Program; and, the Portland Development Commission Green Building Policy financing tool for earth-friendly designs and materials. 34 refs., 2 figs

  10. Performance Analysis of Cool Roof, Green Roof and Thermal Insulation on a Concrete Flat Roof in Tropical Climate

    OpenAIRE

    Zingre, Kishor T.; Yang, Xingguo; Wan, Man Pun

    2015-01-01

    In the tropics, the earth surface receives abundant solar radiation throughout the year contributing significantly to building heat gain and, thus, cooling demand. An effective method that can curb the heat gains through opaque roof surfaces could provide significant energy savings. This study investigates and compares the effectiveness of various passive cooling techniques including cool roof, green roof and thermal insulation for reducing the heat gain through a flat concrete roof in tropic...

  11. IDENTIFYING ROOF FALL PREDICTORS USING FUZZY CLASSIFICATION

    International Nuclear Information System (INIS)

    Bertoncini, C. A.; Hinders, M. K.

    2010-01-01

    Microseismic monitoring involves placing geophones on the rock surfaces of a mine to record seismic activity. Classification of microseismic mine data can be used to predict seismic events in a mine to mitigate mining hazards, such as roof falls, where properly bolting and bracing the roof is often an insufficient method of preventing weak roofs from destabilizing. In this study, six months of recorded acoustic waveforms from microseismic monitoring in a Pennsylvania limestone mine were analyzed using classification techniques to predict roof falls. Fuzzy classification using features selected for computational ease was applied on the mine data. Both large roof fall events could be predicted using a Roof Fall Index (RFI) metric calculated from the results of the fuzzy classification. RFI was successfully used to resolve the two significant roof fall events and predicted both events by at least 15 hours before visual signs of the roof falls were evident.

  12. Comparison of Software Models for Energy Savings from Cool Roofs

    Energy Technology Data Exchange (ETDEWEB)

    New, Joshua Ryan [ORNL; Miller, William A [ORNL; Huang, Yu (Joe) [White Box Technologies; Levinson, Ronnen [Lawrence Berkeley National Laboratory (LBNL)

    2014-01-01

    A web-based Roof Savings Calculator (RSC) has been deployed for the United States Department of Energy as an industry-consensus tool to help building owners, manufacturers, distributors, contractors and researchers easily run complex roof and attic simulations. This tool employs modern web technologies, usability design, and national average defaults as an interface to annual simulations of hour-by-hour, whole-building performance using the world-class simulation tools DOE-2.1E and AtticSim in order to provide estimated annual energy and cost savings. In addition to cool reflective roofs, RSC simulates multiple roof and attic configurations including different roof slopes, above sheathing ventilation, radiant barriers, low-emittance roof surfaces, duct location, duct leakage rates, multiple substrate types, and insulation levels. A base case and energy-efficient alternative can be compared side-by-side to estimate monthly energy. RSC was benchmarked against field data from demonstration homes in Ft. Irwin, California; while cooling savings were similar, heating penalty varied significantly across different simulation engines. RSC results reduce cool roofing cost-effectiveness thus mitigating expected economic incentives for this countermeasure to the urban heat island effect. This paper consolidates comparison of RSC s projected energy savings to other simulation engines including DOE-2.1E, AtticSim, Micropas, and EnergyPlus, and presents preliminary analyses. RSC s algorithms for capturing radiant heat transfer and duct interaction in the attic assembly are considered major contributing factors to increased cooling savings and heating penalties. Comparison to previous simulation-based studies, analysis on the force multiplier of RSC cooling savings and heating penalties, the role of radiative heat exchange in an attic assembly, and changes made for increased accuracy of the duct model are included.

  13. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Science.gov (United States)

    2010-07-01

    ... External floating roof converted into an internal floating roof. The owner or operator who elects to... 40 Protection of Environment 15 2010-07-01 2010-07-01 false External floating roof converted into an internal floating roof. 65.45 Section 65.45 Protection of Environment ENVIRONMENTAL PROTECTION...

  14. Green Roof Potential in Arab Cities

    OpenAIRE

    Attia, Shady

    2014-01-01

    Urban green roofs have long been promoted as an easy and effective strategy for beautifying the built environment and increasing investment opportunity. The building roof is very important because it has a direct impact on thermal comfort and energy conservation in and around buildings. Urban green roofs can help to address the lack of green space in many urban areas. Urban green roofs provides the city with open spaces that helps reduce urban heat island effect and provides the human populat...

  15. The Green Roof Microbiome: Improving Plant Survival for Ecosystem Service Delivery

    Directory of Open Access Journals (Sweden)

    Roberta Fulthorpe

    2018-02-01

    Full Text Available Plants are key contributors to ecosystem services delivered by green roofs in cities including stormwater capture, temperature regulation, and wildlife habitat. As a result, current research has primarily focused on their growth in relationship to extensive green roof (e.g., substrates <15 cm depth ecosystem services. Green roofs are exposed to a variety of harsh abiotic factors such as intense solar radiation, wind, and isolation from ground-level habitats, making survival exceedingly difficult. Plants in natural habitats benefit from a variety of interactions with fungi and bacteria. These plant-microbial interactions improve mechanisms of survival and productivity; however, many green roof substrates are sterilized prior to installation and lack microbial communities with unstudied consequences for green roof plant health and subsequent survival and performance. In this paper, we present six hypotheses on the positive role of microbes in green roof applications. In natural and experimental systems, microbial interactions have been linked to plant (1 drought tolerance, (2 pathogen protection, (3 nutrient availability, (4 salt tolerance, (5 phytohormone production, and (6 substrate stabilization, all of which are desirable properties of green roof ecosystems. As few studies exist that directly examine these relationships on green roofs, we explore the existing ecological literature on these topics to unravel the mechanisms that could support more complex green roof ecosystem and lead to new insight into the design, performance, and broader applications in green infrastructure.

  16. Being the first kid on the block : installing a green roof in an emerging market

    Energy Technology Data Exchange (ETDEWEB)

    Zoll, C. [The Green Inst., Minneapolis, MN (United States)

    2005-07-01

    The Green Institute is an organization dedicated to improving the environment and creating employment opportunities in Minneapolis. This paper provided details of the institute's 2004 installation of a green roof system on the Phillips Eco-Enterprise Center, which was built by the institute in 1999. The building design included geo-exchange heating and cooling, an active day-lighting system, and an energy recovery ventilator. Structural support for a green roof was added during construction. While the rooftop structure was initially designed as an intensive green rooftop, the institute eventually decided to create an extensive green roof system combined with a deck area for visitors. The design of the green roof included a circular central gathering area with spokes. A mixture of sedums were planted, as well as plants native to Minnesota river bluff prairies. A variety of species were planted in order to determine which plant varieties would succeed. This paper provided technical details of the green roof's installation, as well as details of the organizational and administrative procedures required to orchestrate the different contractors and volunteers involved in the project. Details of the materials used for the construction of the roof were also included. The rooftop was opened to the public in 2005, and building tenants currently use the green roof for meetings, lunches and breaks. Television news stations have visited the roof, which is also visible to passengers on the Minneapolis light rail transit line. The Green Institute has continued to promote green roof market development in the city with a variety of green roof events, symposiums and workshops. The institute has also been successful in implementing a credit system to reduce stormwater utility fees for buildings with green roofs.

  17. GREEN ROOFS — A GROWING TREND

    Science.gov (United States)

    One of the most interesting stormwater control systems under evaluation by EPA are “green roofs”. Green roofs are vegetative covers applied to building roofs to slow, or totally absorb, rainfall runoff during storms. While the concept of over-planted roofs is very ancient, the go...

  18. Roofing Materials Assessment: Investigation of Five Metals in Runoff from Roofing Materials.

    Science.gov (United States)

    Winters, Nancy; Granuke, Kyle; McCall, Melissa

    2015-09-01

    To assess the contribution of five toxic metals from new roofing materials to stormwater, runoff was collected from 14 types of roofing materials and controls during 20 rain events and analyzed for metals. Many of the new roofing materials evaluated did not show elevated metals concentrations in the runoff. Runoff from several other roofing materials was significantly higher than the controls for arsenic, copper, and zinc. Notably, treated wood shakes released arsenic and copper, copper roofing released copper, PVC roofing released arsenic, and Zincalume® and EPDM roofing released zinc. For the runoff from some of the roofing materials, metals concentrations decreased significantly over an approximately one-year period of aging. Metals concentrations in runoff were demonstrated to depend on a number of factors, such as roofing materials, age of the materials, and climatic conditions. Thus, application of runoff concentrations from roofing materials to estimate basin-wide releases should be undertaken cautiously.

  19. The green roof dilemma - discussion of Francis and Lorimer (2011).

    Science.gov (United States)

    Henry, Alexandre; Frascaria-Lacoste, Nathalie

    2012-08-15

    Urban ecosystems are the most complex mosaics of vegetative land cover that can be found. In a recent paper, Francis and Lorimer (2011) evaluated the reconciliation potential of living roofs and walls. For these authors, these two techniques for habitat improvement have strong potential for urban reconciliation ecology. However they have some ecological and societal limitations such as the physical extreme environmental characteristics, the monetary investment and the cultural perceptions of urban nature. We are interested in their results and support their conclusions. However, for a considerable time, green roofs have been designed to provide urban greenery for buildings and the green roof market has only focused on extensive roof at a restricted scale within cities. Thus, we have strong doubts about the relevance of their use as possible integrated elements of the network. Furthermore, without dynamic progress in research and the implementation of well-thought-out policies, what will be the real capital gain from green roofs with respect to land-use complementation in cities? If we agree with Francis and Lorimer (2011) considering that urban reconciliation ecology between nature and citizens is a current major challenge, then "adaptive collaborative management" is a fundamental requirement. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Spatial environmental heterogeneity affects plant growth and thermal performance on a green roof

    Energy Technology Data Exchange (ETDEWEB)

    Buckland-Nicks, Michael; Heim, Amy; Lundholm, Jeremy, E-mail: jlundholm@smu.ca

    2016-05-15

    Green roofs provide ecosystem services, including stormwater retention and reductions in heat transfer through the roof. Microclimates, as well as designed features of green roofs, such as substrate and vegetation, affect the magnitude of these services. Many green roofs are partially shaded by surrounding buildings, but the effects of this within-roof spatial environmental heterogeneity on thermal performance and other ecosystem services have not been examined. We quantified the effects of spatial heterogeneity in solar radiation, substrate depth and other variables affected by these drivers on vegetation and ecosystem services in an extensive green roof. Spatial heterogeneity in substrate depth and insolation were correlated with differential growth, survival and flowering in two focal plant species. These effects were likely driven by the resulting spatial heterogeneity in substrate temperature and moisture content. Thermal performance (indicated by heat flux and substrate temperature) was influenced by spatial heterogeneity in vegetation cover and substrate depth. Areas with less insolation were cooler in summer and had greater substrate moisture, leading to more favorable conditions for plant growth and survival. Spatial variation in substrate moisture (7%–26% volumetric moisture content) and temperature (21 °C–36 °C) during hot sunny conditions in summer could cause large differences in stormwater retention and heat flux within a single green roof. Shaded areas promote smaller heat fluxes through the roof, leading to energy savings, but lower evapotranspiration in these areas should reduce stormwater retention capacity. Spatial heterogeneity can thus result in trade-offs between different ecosystem services. The effects of these spatial heterogeneities are likely widespread in green roofs. Structures that provide shelter from sun and wind may be productively utilized to design higher functioning green roofs and increase biodiversity by providing habitat

  1. Spatial environmental heterogeneity affects plant growth and thermal performance on a green roof

    International Nuclear Information System (INIS)

    Buckland-Nicks, Michael; Heim, Amy; Lundholm, Jeremy

    2016-01-01

    Green roofs provide ecosystem services, including stormwater retention and reductions in heat transfer through the roof. Microclimates, as well as designed features of green roofs, such as substrate and vegetation, affect the magnitude of these services. Many green roofs are partially shaded by surrounding buildings, but the effects of this within-roof spatial environmental heterogeneity on thermal performance and other ecosystem services have not been examined. We quantified the effects of spatial heterogeneity in solar radiation, substrate depth and other variables affected by these drivers on vegetation and ecosystem services in an extensive green roof. Spatial heterogeneity in substrate depth and insolation were correlated with differential growth, survival and flowering in two focal plant species. These effects were likely driven by the resulting spatial heterogeneity in substrate temperature and moisture content. Thermal performance (indicated by heat flux and substrate temperature) was influenced by spatial heterogeneity in vegetation cover and substrate depth. Areas with less insolation were cooler in summer and had greater substrate moisture, leading to more favorable conditions for plant growth and survival. Spatial variation in substrate moisture (7%–26% volumetric moisture content) and temperature (21 °C–36 °C) during hot sunny conditions in summer could cause large differences in stormwater retention and heat flux within a single green roof. Shaded areas promote smaller heat fluxes through the roof, leading to energy savings, but lower evapotranspiration in these areas should reduce stormwater retention capacity. Spatial heterogeneity can thus result in trade-offs between different ecosystem services. The effects of these spatial heterogeneities are likely widespread in green roofs. Structures that provide shelter from sun and wind may be productively utilized to design higher functioning green roofs and increase biodiversity by providing habitat

  2. PREDICTING THERMAL PERFORMANCE OF ROOFING SYSTEMS IN SURABAYA

    Directory of Open Access Journals (Sweden)

    MINTOROGO Danny Santoso

    2015-07-01

    Full Text Available Traditional roofing systems in the developing country likes Indonesia are still be dominated by the 30o, 45o, and more pitched angle roofs; the roofing cover materials are widely used to traditional clay roof tiles, then modern concrete roof tiles, and ceramic roof tiles. In the 90’s decay, shop houses are prosperous built with flat concrete roofs dominant. Green roofs and roof ponds are almost rarely built to meet the sustainable environmental issues. Some tested various roof systems in Surabaya were carried out to observe the roof thermal performances. Mathematical equation model from three references are also performed in order to compare with the real project tested. Calculated with equation (Kabre et al., the 30o pitched concrete-roof-tile, 30o clay-roof-tile, 45o pitched concrete-roof-tile are the worst thermal heat flux coming to room respectively. In contrast, the bare soil concrete roof and roof pond system are the least heat flux streamed onto room. Based on predicted calculation without insulation and cross-ventilation attic space, the roof pond and bare soil concrete roof (greenery roof are the appropriate roof systems for the Surabaya’s climate; meanwhile the most un-recommended roof is pitched 30o or 45o angle with concrete-roof tiles roofing systems.

  3. Crystalline roof glazing - Westside shopping centre, Berne; Kristalline Dachverglasungen

    Energy Technology Data Exchange (ETDEWEB)

    Enkerli, W.

    2009-07-01

    This illustrated article takes a look at the new shopping and leisure centre on the western outskirts of Berne, Switzerland. In particular, the roof of this unusual building over the motorway with its sloping walls and zig-zag design is looked at. The centre's shopping mall, adventure baths and spa, a multiplex cinema, an old peoples' home and a hotel are briefly discussed, as is the embedding of the centre in its suburban environment. The roof construction with its crystalline skylights is examined and discussed in detail. The centre's building technical services are also briefly commented on.

  4. Orbital roof encephalocele mimicking a destructive neoplasm.

    Science.gov (United States)

    Alsuhaibani, Adel H; Hitchon, Patrick W; Smoker, Wendy R K; Lee, Andrew G; Nerad, Jeffrey A

    2011-01-01

    The purpose of this case report is to report an orbital roof encephalocele mimicking a destructive orbital neoplasm. Orbital roof encephalocele is uncommon but can mimic neoplasm. One potential mechanism for the orbital roof destruction is a post-traumatic "growing orbital roof fracture." The growing fracture has been reported mostly in children but can occur in adults. Alternative potential etiologies for the encephalocele are discussed, including Gorham syndrome. Orbital roof encephalocele is uncommon in adults, and the findings can superficially resemble an orbital neoplasm. Radiographic and clinical features that might suggest the correct diagnosis include a prior history of trauma, overlying frontal lobe encephalomalacia without significant mass effect or edema, and an orbital roof defect. The "growing fracture" mechanism may be a potential explanation for the orbital roof destruction in some cases.

  5. Generating realistic roofs over a rectilinear polygon

    KAUST Repository

    Ahn, Heekap

    2011-01-01

    Given a simple rectilinear polygon P in the xy-plane, a roof over P is a terrain over P whose faces are supported by planes through edges of P that make a dihedral angle π/4 with the xy-plane. In this paper, we introduce realistic roofs by imposing a few additional constraints. We investigate the geometric and combinatorial properties of realistic roofs, and show a connection with the straight skeleton of P. We show that the maximum possible number of distinct realistic roofs over P is ( ⌊(n-4)/4⌋ (n-4)/2) when P has n vertices. We present an algorithm that enumerates a combinatorial representation of each such roof in O(1) time per roof without repetition, after O(n 4) preprocessing time. We also present an O(n 5)-time algorithm for computing a realistic roof with minimum height or volume. © 2011 Springer-Verlag.

  6. Quantitative analysis on the urban flood mitigation effect by the extensive green roof system.

    Science.gov (United States)

    Lee, J Y; Moon, H J; Kim, T I; Kim, H W; Han, M Y

    2013-10-01

    Extensive green-roof systems are expected to have a synergetic effect in mitigating urban runoff, decreasing temperature and supplying water to a building. Mitigation of runoff through rainwater retention requires the effective design of a green-roof catchment. This study identified how to improve building runoff mitigation through quantitative analysis of an extensive green-roof system. Quantitative analysis of green-roof runoff characteristics indicated that the extensive green roof has a high water-retaining capacity response to rainfall of less than 20 mm/h. As the rainfall intensity increased, the water-retaining capacity decreased. The catchment efficiency of an extensive green roof ranged from 0.44 to 0.52, indicating reduced runoff comparing with efficiency of 0.9 for a concrete roof. Therefore, extensive green roofs are an effective storm water best-management practice and the proposed parameters can be applied to an algorithm for rainwater-harvesting tank design. © 2013 Elsevier Ltd. All rights reserved.

  7. Powered roof supports today - and tomorrow. [2 refs

    Energy Technology Data Exchange (ETDEWEB)

    Shepherd, R

    1977-02-01

    Coalface support has progressed considerably since the days when the first, then revolutionary, hydraulic and mechanical sliding props were introduced to supplant timber and rigid steel, and as each week passes the methods and the equipment now used seem to get more sophisticated. An explanation is presented on how newer designs of powered roof support are being developed to meet the latest challenges.

  8. Asphalt and Wood Shingling. Roofing Workbook and Tests.

    Science.gov (United States)

    Brown, Arthur

    This combination workbook and set of tests contains materials on asphalt and wood shingling that have been designed to be used by those studying to enter the roofing and waterproofing trade. It consists of seven instructional units and seven accompanying objective tests. Covered in the individual units are the following topics: shingling…

  9. Two-dimensional modeling of water and heat fluxes in green roof substrates

    Science.gov (United States)

    Suarez, F. I.; Sandoval, V. P.

    2016-12-01

    Due to public concern towards sustainable development, greenhouse gas emissions and energy efficiency, green roofs have become popular in the last years. Green roofs integrate vegetation into infrastructures to reach additional benefits that minimize negative impacts of the urbanization. A properly designed green roof can reduce environmental pollution, noise levels, energetic requirements or surface runoff. The correct performance of green roofs depends on site-specific conditions and on each component of the roof. The substrate and the vegetation layers strongly influence water and heat fluxes on a green roof. The substrate is an artificial media that has an improved performance compared to natural soils as it provides critical resources for vegetation survival: water, nutrients, and a growing media. Hence, it is important to study the effects of substrate properties on green roof performance. The objective of this work is to investigate how the thermal and hydraulic properties affect the behavior of a green roof through numerical modeling. The substrates that were investigated are composed by: crushed bricks and organic soil (S1); peat with perlite (S2); crushed bricks (S3); mineral soil with tree leaves (S4); and a mixture of topsoil and mineral soil (S5). The numerical model utilizes summer-arid meteorological information to evaluate the performance of each substrate. Results show that the area below the water retention curve helps to define the substrate that retains more water. In addition, the non-linearity of the water retention curve can increment the water needed to irrigate the roof. The heat propagation through the roof depends strongly on the hydraulic behavior, meaning that a combination of a substrate with low thermal conductivity and more porosity can reduce the heat fluxes across the roof. Therefore, it can minimize the energy consumed of an air-conditioner system.

  10. Habitat connectivity shapes urban arthropod communities: the key role of green roofs.

    Science.gov (United States)

    Braaker, S; Ghazoul, J; Obrist, M K; Moretti, M

    2014-04-01

    that eventually even communities of low-mobility species become connected. Furthermore, improving the design of green roofs (composition and configuration of vegetation and soil types) could enhance the ecological value, particularly for low-mobility species.

  11. Thermal and Energy Performance of Conditioned Building Due To Insulated Sloped Roof

    Science.gov (United States)

    Irwan, Suhandi Syiful; Ahmed, Azni Zain; Zakaria, Nor Zaini; Ibrahim, Norhati

    2010-07-01

    For low-rise buildings in equatorial region, the roof is exposed to solar radiation longer than other parts of the envelope. Roofs are to be designed to reject heat and moderate the thermal impact. These are determined by the design and construction of the roofing system. The pitch of roof and the properties of construction affect the heat gain into the attic and subsequently the indoor temperature of the living spaces underneath. This finally influences the thermal comfort conditions of naturally ventilated buildings and cooling load of conditioned buildings. This study investigated the effect of insulated sloping roof on thermal energy performance of the building. A whole-building thermal energy computer simulation tool, Integrated Environmental Solution (IES), was used for the modelling and analyses. A building model with dimension of 4.0 m × 4.0 m × 3.0 m was designed with insulated roof and conventional construction for other parts of the envelope. A 75 mm conductive insulation material with thermal conductivity (k-value) of 0.034 Wm-1K-1 was installed underneath the roof tiles. The building was modelled with roof pitch angles of 0° , 15°, 30°, 45°, 60° and simulated for the month of August in Malaysian climate conditions. The profile for attic temperature, indoor temperature and cooling load were downloaded and evaluated. The optimum roof pitch angle for best thermal performance and energy saving was identified. The results show the pitch angle of 0° is able to mitigate the thermal impact to provide the best thermal condition with optimum energy savings. The maximum temperature difference between insulated and non-insulted roof for attic (AtticA-B) and indoor condition (IndoorA-B) is +7.8 °C and 0.4 °C respectively with an average energy monthly savings of 3.9 %.

  12. Polyurethane adhesives in flat roofs

    OpenAIRE

    Bogárová Markéta; Stodůlka Jindřich; Šuhajda Karel

    2017-01-01

    It is necessary to stabilize individual layers of flat roofs, mainly because of wind suction. Apart from anchoring and surcharge, these layers can be secured by bonding. At present gluing is an indispensable and widely used stabilization method. On our market we can found many types of adhesives, most widely used are based on polyurethane. This paper focuses on problematic about stabilization thermal insulation from expanded polystyrene to vapor barrier from bitumen. One of the main issues is...

  13. Telescopic mine roof-support

    Energy Technology Data Exchange (ETDEWEB)

    Piscitelli, A

    1989-05-17

    A mining roof support which includes a main body consisting of a pair of telescopically associated elongated members and which slide relative to each other to extend the support, engaging one of the members. A locking plate which is movable into engagement with the member by means of a lever operated cam causes tilting of the plate to engage the member and then to raise the member and lock it in the raised position. 1 fig.

  14. Polyurethane adhesives in flat roofs

    Directory of Open Access Journals (Sweden)

    Bogárová Markéta

    2017-01-01

    Full Text Available It is necessary to stabilize individual layers of flat roofs, mainly because of wind suction. Apart from anchoring and surcharge, these layers can be secured by bonding. At present gluing is an indispensable and widely used stabilization method. On our market we can found many types of adhesives, most widely used are based on polyurethane. This paper focuses on problematic about stabilization thermal insulation from expanded polystyrene to vapor barrier from bitumen. One of the main issues is to calculate the exact amount of adhesive, which is required to guarantee the resistance against wind suction. In this problematic we can not find help neither in technical data sheets provided by the manufactures. Some of these data sheets contain at least information about amount of adhesive depending on location in roof plane and building height, but they do not specify the strength of such connection. It was therefore resorted to select several representatives polyurethane adhesives and their subsequent testing on specimens simulating the flat roof segment. The paper described the test methodology and results for two types of polyurethane adhesives.

  15. Roof Box Shape Streamline Adaptation and the Impact towards Fuel Consumption

    Directory of Open Access Journals (Sweden)

    Abdul Latif M.F.

    2017-01-01

    Full Text Available The fuel price hike is currently a sensational national issue in Malaysia. Since the rationalization of fuel subsidies many were affected especially the middle income family. Vehicle aerodynamic were directly related to the fuel consumption, were extra frontal area result a higher drag force hence higher fuel consumption. Roof box were among the largest contributor to the extra drag, thus the roof box shape rationalization were prominent to reduce the extra drag. The idea of adopting water drop shape to the roof box design shows prominent result. The roof box has been simulated using MIRA virtual wind tunnel modelling via commercial computational fluid dynamic (CFD package. This streamline shape drastically reduce the drag force by 34% resulting to a 1.7% fuel saving compare to the conventional boxy roof box. This is an effort to reduce the carbon foot print for a sustainable green world.

  16. Estimation of exposure to sunlight of the liner under a tiled roof

    DEFF Research Database (Denmark)

    Holck, Ole; Rosenfeld, J.L.J.

    2005-01-01

    One construction for a pitched roof is to use tiles on battens, with a liner attached below the battens. The shape of some types of tiles is such that, at each corner where four tiles overlap, a small gap is formed. At certain positions of the sun solar radiation can penetrate through these gaps....... Simulations were carried out for a roof tilted at 25degrees, 35degrees or 45degrees, facing SE, S, SW or W. For the particular roof construction and gap studied, the maximum annual exposure of a 25 mm(2) piece of the liner placed 150 mm below the gap (corresponding to about 100 mm below the base of the tiles...... to the roof. Analytic expressions for the size of the illuminated area are obtained using a thick slit model. The accuracy of the model was assessed by some experimental measurements. The exposure over one year of the roof liner was calculated using the Design Reference Year for Copenhagen, Denmark...

  17. Factors Influencing Arthropod Diversity on Green Roofs

    Directory of Open Access Journals (Sweden)

    Bracha Y. Schindler

    2011-01-01

    Full Text Available Green roofs have potential for providing substantial habitat to plants, birds, and arthropod species that are not well supported by other urban habitats. Whereas the plants on a typical green roof are chosen and planted by people, the arthropods that colonize it can serve as an indicator of the ability of this novel habitat to support a diverse community of organisms. The goal of this observational study was to determine which physical characteristics of a roof or characteristics of its vegetation correlate with arthropod diversity on the roof. We intensively sampled the number of insect families on one roof with pitfall traps and also measured the soil arthropod species richness on six green roofs in the Boston, MA area. We found that the number of arthropod species in soil, and arthropod families in pitfall traps, was positively correlated with living vegetation cover. The number of arthropod species was not significantly correlated with plant diversity, green roof size, distance from the ground, or distance to the nearest vegetated habitat from the roof. Our results suggest that vegetation cover may be more important than vegetation diversity for roof arthropod diversity, at least for the first few years after establishment. Additionally, we found that even green roofs that are small and isolated can support a community of arthropods that include important functional groups of the soil food web.

  18. Green living roof implementation and influences of the soil layer on its properties

    Directory of Open Access Journals (Sweden)

    Dimitrijević Dragana G.

    2016-01-01

    Full Text Available Affected by undeniable climatic change, the temperature of the urban areas rises continually, increasing rapidly the energy problem of cities and amplifying the pollution problems. The thermal stress is increased, thus both the indoor and the outdoor thermal comfort levels are decreased, enhancing the health problems. Green roof implementation in the building envelope is strategy that provides heat island amelioration, thermal comfort for occupants and reduces energy consumption of buildings. Green living roofs are a passive cooling technique, which can stop the incoming solar radiation from reaching the building structure below. In this paper, we assessed the importance of the green roofs in providing environmental and building energy benefits, and brief investigation on the different configuration of the soil layer in the green roof assembly influences to the temperature of the roof surface was presented. Investigation was conducted for first phase of the living roof growth. Four cells were designed in SolidWorks software where the transient thermal study was performed in order to determine differences between the behavior of the conventional roof and three green roof types.

  19. Energy and Economic Evaluation of Green Roofs for Residential Buildings in Hot-Humid Climates

    Directory of Open Access Journals (Sweden)

    Abubakar S. Mahmoud

    2017-03-01

    Full Text Available Green roofs may be considered a passive energy saving technology that also offer benefits like environmental friendliness and enhancement of aesthetic and architectural qualities of buildings. This paper examines the energy and economic viability of the green roof technology in the hot humid climate of Saudi Arabia by considering a modern four bedroom residential building in the city of Dhahran as a case study. The base case and green roof modelling of the selected building has been developed with the help of DesignBuilder software. The base case model has been validated with the help of 3-month measured data about the energy consumption without a green roof installed. The result shows that the energy consumption for the base case is 169 kWh/m2 while the energy consumption due to the application of a green roof on the entire roof surface is 110 kWh/m2. For the three investigated green roof options, energy saving is found to be in the range of 24% to 35%. The economic evaluation based on the net present value (NPV approach for 40 years with consideration to other environmental advantages indicates that the benefits of the green roof technology are realized towards the end of the life cycle of the building.

  20. Wind Tunnel Tests for Wind Pressure Distribution on Gable Roof Buildings

    Science.gov (United States)

    2013-01-01

    Gable roof buildings are widely used in industrial buildings. Based on wind tunnel tests with rigid models, wind pressure distributions on gable roof buildings with different aspect ratios were measured simultaneously. Some characteristics of the measured wind pressure field on the surfaces of the models were analyzed, including mean wind pressure, fluctuating wind pressure, peak negative wind pressure, and characteristics of proper orthogonal decomposition results of the measured wind pressure field. The results show that extremely high local suctions often occur in the leading edges of longitudinal wall and windward roof, roof corner, and roof ridge which are the severe damaged locations under strong wind. The aspect ratio of building has a certain effect on the mean wind pressure coefficients, and the effect relates to wind attack angle. Compared with experimental results, the region division of roof corner and roof ridge from AIJ2004 is more reasonable than those from CECS102:2002 and MBMA2006.The contributions of the first several eigenvectors to the overall wind pressure distributions become much bigger. The investigation can offer some basic understanding for estimating wind load distribution on gable roof buildings and facilitate wind-resistant design of cladding components and their connections considering wind load path. PMID:24082851

  1. Rock characterization while drilling and application of roof bolter drilling data for evaluation of ground conditions

    Directory of Open Access Journals (Sweden)

    Jamal Rostami

    2015-06-01

    Full Text Available Despite recent advances in mine health and safety, roof collapse and instabilities are still the leading causes of injury and fatality in underground mining operations. Improving safety and optimum design of ground support requires good and reliable ground characterization. While many geophysical methods have been developed for ground characterizations, their accuracy is insufficient for customized ground support design of underground workings. The actual measurements on the samples of the roof and wall strata from the exploration boring are reliable but the related holes are far apart, thus unsuitable for design purposes. The best source of information could be the geological back mapping of the roof and walls, but this is disruptive to mining operations, and provided information is only from rock surface. Interpretation of the data obtained from roof bolt drilling can offer a good and reliable source of information that can be used for ground characterization and ground support design and evaluations. This paper offers a brief review of the mine roof characterization methods, followed by introduction and discussion of the roof characterization methods by instrumented roof bolters. A brief overview of the results of the preliminary study and initial testing on an instrumented drill and summary of the suggested improvements are also discussed.

  2. Framing Failures in Wood-Frame Hip Roofs under Extreme Wind Loads

    Directory of Open Access Journals (Sweden)

    Sarah A. Stevenson

    2018-02-01

    Full Text Available Wood-frame residential roof failures are among the most common and expensive types of wind damage. Hip roofs are commonly understood to be more resilient during extreme wind in relation to gable roofs. However, inspection of damage survey data from recent tornadoes has revealed a previously unstudied failure mode in which hip roofs suffer partial failure of the framing structure. In the current study, evidence of partial framing failures and statistics of their occurrence are explored and discussed, while the common roof design and construction practice are reviewed. Two-dimensional finite element models are developed to estimate the element-level load effects on hip roof trusses and stick-frame components. The likelihood of failure in each member is defined based on relative demand-to-capacity ratios. Trussed and stick-frame structures are compared to assess the relative performance of the two types of construction. The present analyses verify the common understanding that toenailed roof-to-wall connections are likely to be the most vulnerable elements in the structure of a wood-frame hip roof. However, the results also indicate that certain framing members and connections display significant vulnerability under the same wind uplift, and the possibility of framing failure is not to be discounted. Furthermore, in the case where the roof-to-wall connection uses hurricane straps, certain framing members and joints become the likely points of failure initiation. The analysis results and damage survey observations are used to expand the understanding of wood-frame residential roof failures, as they relate to the Enhanced Fujita Scale and provide assessment of potential gaps in residential design codes.

  3. Spatial environmental heterogeneity affects plant growth and thermal performance on a green roof.

    Science.gov (United States)

    Buckland-Nicks, Michael; Heim, Amy; Lundholm, Jeremy

    2016-05-15

    Green roofs provide ecosystem services, including stormwater retention and reductions in heat transfer through the roof. Microclimates, as well as designed features of green roofs, such as substrate and vegetation, affect the magnitude of these services. Many green roofs are partially shaded by surrounding buildings, but the effects of this within-roof spatial environmental heterogeneity on thermal performance and other ecosystem services have not been examined. We quantified the effects of spatial heterogeneity in solar radiation, substrate depth and other variables affected by these drivers on vegetation and ecosystem services in an extensive green roof. Spatial heterogeneity in substrate depth and insolation were correlated with differential growth, survival and flowering in two focal plant species. These effects were likely driven by the resulting spatial heterogeneity in substrate temperature and moisture content. Thermal performance (indicated by heat flux and substrate temperature) was influenced by spatial heterogeneity in vegetation cover and substrate depth. Areas with less insolation were cooler in summer and had greater substrate moisture, leading to more favorable conditions for plant growth and survival. Spatial variation in substrate moisture (7%-26% volumetric moisture content) and temperature (21°C-36°C) during hot sunny conditions in summer could cause large differences in stormwater retention and heat flux within a single green roof. Shaded areas promote smaller heat fluxes through the roof, leading to energy savings, but lower evapotranspiration in these areas should reduce stormwater retention capacity. Spatial heterogeneity can thus result in trade-offs between different ecosystem services. The effects of these spatial heterogeneities are likely widespread in green roofs. Structures that provide shelter from sun and wind may be productively utilized to design higher functioning green roofs and increase biodiversity by providing habitat

  4. Mine roof supports

    Energy Technology Data Exchange (ETDEWEB)

    Cook, S.P.

    1983-09-28

    The area of application of this invention relates to the hydraulic system of props in mine supports. Hydraulic props are normally equipped with backup equipment for use in case of failure of the primary hydraulic line. The proposed system includes the main hydraulic circuit with a control valve, an auxillary hydraulic line with a control valve and a limiter designed to close this valve when the necessary pressure level is attained in the hydraulic props. The limiter may be mechanical, electrical or hydraulic. The principle of operation of the system is as follows: if the pressure in the main hydraulic line falls off for some reason, the hydraulic cylinder connected to the props is actuated; this cylinder activates the shut-off valve in the auxillary hydraulic line by opening it. The open time of this line is controlled by a residual pressure limiter. The system is easily controlled and provides a constant emulsion pressure in the props.

  5. Condition Assessment Survey (CAS) Program. Deficiency standards and inspections methods manual: Volume 5, 0.05 Roofing

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    General information is presented for asset determinant factor/CAS repair codes/CAS cost factors; guide sheet tool & material listing; testing methods; inspection frequency; standard system design life tables; and system work breakdown structure. Deficiency standards and inspection methods are presented for built-up membrane; single- ply membrane; metal roofing systems; coated foam membrane; shingles; tiles; parapets; roof drainage system; roof specialties; and skylights.

  6. Retention performance of green roofs in representative climates worldwide

    Science.gov (United States)

    Viola, F.; Hellies, M.; Deidda, R.

    2017-10-01

    role of climatic conditions, namely annual rainfall, potential evapotranspiration and their seasonality cycles, we found that they drive green roofs retention performance, which are the maxima when rainfall and temperature are in phase. Finally, we provide design charts for a first approximation of possible hydrological benefits deriving from the implementation of intensive or extensive green roofs in different world areas. As an example, 25 big cities have been indicated as benchmark case studies.

  7. Sustainability of thermoplastic vinyl roofing membrane systems

    Energy Technology Data Exchange (ETDEWEB)

    Graveline, S. P. [Sika Sanarfil, Canton, (United States)

    2010-07-01

    The International Council for Research and Innovation in Building and Construction (CIB-RILEM) has developed a framework for sustainable roofing based on a series of tenets divided into three key areas: preservation of the environment, conservation of energy, and extended roof life. This paper investigated the sustainability of thermoplastic vinyl roof membranes using these guidelines and the relevant tenets for roof system selection. Several tenets provided alternatives for minimizing the burden on the environment using non-renewable raw materials, conserving energy with thermal insulation, and extending the lifespan of all roof components by using long lasting membranes. A life cycle assessment was carried out to provide a quantitative framework for assessing the sustainability of roofing materials. It was found that the PVC membrane systems had a lesser impact on the environment than other competing systems.

  8. A novel solar multifunctional PV/T/D system for green building roofs

    International Nuclear Information System (INIS)

    Feng, Chaoqing; Zheng, Hongfei; Wang, Rui; Yu, Xu; Su, Yuehong

    2015-01-01

    Highlights: • A novel transparent roof combines the solar PV/T/D system with green building design. • Novel photovoltaic-thermal roofing design can achieve excellent light control at noon. • The roof has no obvious influence on indoor light intensity in morning and afternoon. • Higher efficiency of solar energy utilization could be achieved with new roofing. - Abstract: A novel transparent roof which is made of solid CPC (Compound Parabolic Concentrator) PV/T/D (Photovoltaic/Thermal/Day lighting) system is presented. It combines the solar PV/T/D system with green building design. The PV/T/D system can achieve excellent light control at noon and adjust the thermal environment in the building, such that high efficiency utilization of solar energy could be achieved in modern architecture. This kind of roof can increase the visual comfort for building occupants; it can also avoid the building interior from overheating and dazzling at noon which is caused by direct sunlight through transparent roof. Optical simulation software is used to track the light path in different incidence angles. CFD (Computational Fluid Dynamics) simulation and steady state experiment have been taken to investigate the thermal characteristic of PV/T/D device. Finally, the PV/T/D experimental system was built; and the PV efficiency, light transmittance and air heating power of the system are tested under real sky conditions

  9. Extensive Green Roof Ecological Benefits in Latvia

    OpenAIRE

    Rušenieks, Rihards; Kamenders, Agris

    2013-01-01

    Extensive green roof ecological benefits are studiedin this paper. The research contains a brief explanation aboutgreen roof technology and green roof ecological benefits. Greenroof capability to retain rainwater runoff by accumulating it instorage layers and conducting it back into the atmospherethrough evapotranspiration is studied and modeled. Modeling isdone in Stormwater Management Model 5.0 software. The modelis based on an existing warehouse-type building located in Rigaand hourly Riga...

  10. Key factors in successful green roof training

    International Nuclear Information System (INIS)

    Seeger, H.; Ansel, W.

    2004-01-01

    The green roof market in Germany has increased significantly in the past 3 decades, reaching a market share of 11 to 14 per cent. Three factors were responsible for the success of the green roof movement in Germany, namely the early introduction of quality standards and guidelines; the scientific investigation of ecological and economic benefits and the development of innovative and reliable technologies. In addition, seminars and workshops targeted at relevant groups encouraged green roof construction. Training courses and seminars proved to be efficient communication tools with the advantage of direct feedback from the participants to address sophisticated green roof problems and to integrate current ecological and economic frameworks. The content of the courses were tailored to the specific needs of the participants. In addition, organizers had considerable knowledge of green roof technology and related disciplines. The green roof guidelines in Germany are based on a range of scientific studies from universities, technical colleges and regional research institutions. These studies explored the technical performance of different green roof constructions and the ecological benefits for people and the environment. The market development in Germany is backed by the development of a wide range of innovative technologies which offer solutions for nearly all green roof issues, such as landscaping of sloped, barrel shaped roofs with low load bearing capacities. The German company ZinCo offers the international market a range of well tested and proven green roof systems for intensive and extensive roofs. Their flexible modular products can be adapted to the needs of different roof constructions and to locally specific climatic conditions. 6 refs., 1 fig

  11. Performance Evaluation of Advanced Retrofit Roof Technologies Using Field-Test Data Phase Three Final Report, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Kaushik [ORNL; Childs, Phillip W [ORNL; Atchley, Jerald Allen [ORNL

    2014-05-01

    This article presents various metal roof configurations that were tested at Oak Ridge National Laboratory in Tennessee, U.S.A. between 2009 and 2013, and describes their potential for reducing the attic-generated space conditioning loads. These roofs contained different combinations of phase change material, rigid insulation, low emittance surface and above-sheathing ventilation, with standing-seam metal panels on top. These roofs were designed to be installed on existing roofs decks, or on top of asphalt shingles for retrofit construction. All the tested roofs showed the potential for substantial energy savings compared to an asphalt shingle roof, which was used as a control for comparison. The roofs were constructed on a series of adjacent attics separated at the gables using thick foam insulation. The attics were built on top of a conditioned room. All attics were vented at the soffit and ridge. The test roofs and attics were instrumented with an array of thermocouples. Heat flux transducers were installed in the roof deck and attic floor (ceiling) to measure the heat flows through the roof and between the attic and conditioned space below. Temperature and heat flux data were collected during the heating, cooling and swing seasons over a 3 year period. Data from previous years of testing have been published. Here, data from the latest roof configurations being tested in year 3 of the project are presented. All test roofs were highly effective in reducing the heat flows through the roof and ceiling, and in reducing the diurnal attic temperature fluctuations.

  12. Garden roof in the southwest for environmental benefits : the School of Public Health

    Energy Technology Data Exchange (ETDEWEB)

    Schaack, K.A. [Roof Consultants Inst., Raleigh, NC (United States). Green Roof Research Committee]|[Roofing Contractors Assoc. of Texas, Pflugerville, TX (United States)]|[Gulf Coast Roof Management Inst., Houston, TX (United States)

    2004-07-01

    A recent roof renovation at the University of Texas Health Science Center in Houston (UTHSC) was based on the principles of sustainable development in order to create a place of health and well-being and to pursue integrated design solutions. The project addressed issues associated with the urban heat island condition, and problematic air quality in Houston. The first roofing option that was considered was Cool Roofing that would use either a white reflective surfacing or a garden roof. One of the buildings planned for roof replacement was the School of Public Health, a 10-storey structure composed of structural concrete framing. The existing roof system consisted of a spray-applied polyurethane foam roof covering applied over a gravel surfaced built-up roof membrane that was installed over a thermosetting asphaltic fill installed over a structural concrete deck. It was determined that this roof would be a good potential candidate for the installation of an extensive garden roof system. Four different mock-up samples of various extensive garden roof assemblies were constructed to test representative material types and assemblies. The subject area was divided into the following 4 quadrants in which the following systems were installed: (1) American Hydrotech system with Monolithic Membrane 6125-FR consisting of a hot-applied rubberized liquid asphalt reinforced with a polyester fabric, (2) Sarnafil G 476 system consisting of a prefabricated, fiberglass reinforced PVC thermoplastic single-ply membrane that is 80 mils thick, (3) Grace system with Procor Deck System 3R consisting of a cold-vulcanized, fluid-applied synthetic rubber membrane with a polyester reinforcing fabric, and (4) Siplast with Teranap System consisting of a two-ply SBS modified bitumen membrane composed of a smooth-surfaced modified bitumen fiberglass-reinforced base. After the installation of the growing medium, UTHSC personnel planted a variety of vegetation species and seeds in the quadrants

  13. Green roofs provide habitat for urban bats

    Directory of Open Access Journals (Sweden)

    K.L. Parkins

    2015-07-01

    Full Text Available Understanding bat use of human-altered habitat is critical for developing effective conservation plans for this ecologically important taxon. Green roofs, building rooftops covered in growing medium and vegetation, are increasingly important conservation tools that make use of underutilized space to provide breeding and foraging grounds for urban wildlife. Green roofs are especially important in highly urbanized areas such as New York City (NYC, which has more rooftops (34% than green space (13%. To date, no studies have examined the extent to which North American bats utilize urban green roofs. To investigate the role of green roofs in supporting urban bats, we monitored bat activity using ultrasonic recorders on four green and four conventional roofs located in highly developed areas of NYC, which were paired to control for location, height, and local variability in surrounding habitat and species diversity. We then identified bat vocalizations on these recordings to the species level. We documented the presence of five of nine possible bat species over both roof types: Lasiurus borealis, L. cinereus, L. noctivagans, P. subflavus,andE. fuscus. Of the bat calls that could be identified to the species level, 66% were from L. borealis. Overall levels of bat activity were higher over green roofs than over conventional roofs. This study provides evidence that, in addition to well documented ecosystem benefits, urban green roofs contribute to urban habitat availability for several North American bat species.

  14. Realistic roofs over a rectilinear polygon

    KAUST Repository

    Ahn, Heekap

    2013-11-01

    Given a simple rectilinear polygon P in the xy-plane, a roof over P is a terrain over P whose faces are supported by planes through edges of P that make a dihedral angle π/4 with the xy-plane. According to this definition, some roofs may have faces isolated from the boundary of P or even local minima, which are undesirable for several practical reasons. In this paper, we introduce realistic roofs by imposing a few additional constraints. We investigate the geometric and combinatorial properties of realistic roofs and show that the straight skeleton induces a realistic roof with maximum height and volume. We also show that the maximum possible number of distinct realistic roofs over P is ((n-4)(n-4)/4 /2⌋) when P has n vertices. We present an algorithm that enumerates a combinatorial representation of each such roof in O(1) time per roof without repetition, after O(n4) preprocessing time. We also present an O(n5)-time algorithm for computing a realistic roof with minimum height or volume. © 2013 Elsevier B.V.

  15. A field study to evaluate the impact of different factors on the nutrient pollutant concentrations in green roof runoff.

    Science.gov (United States)

    Wang, Xiaochen; Zhao, Xinhua; Peng, Chenrui; Zhang, Xinbo; Wang, Jianghai

    2013-01-01

    The objectives of this study are to investigate the impact of different factors on the nutrient pollutant concentrations in green roof runoff and to provide reference data for the engineering design of dual substrate layer green roofs. The data were collected from eight different trays under three kinds of artificial rains. The results showed that except for total phosphorus, dual substrate layer green roofs behaved as a sink for most of the nutrient pollutants (significant at p green roof and the depth of the adsorption substrates. Compared with the influence of the substrates, the influence of the plant density and drainage systems was small.

  16. A Fiber Bragg Grating-Based Monitoring System for Roof Safety Control in Underground Coal Mining

    Directory of Open Access Journals (Sweden)

    Yiming Zhao

    2016-10-01

    Full Text Available Monitoring of roof activity is a primary measure adopted in the prevention of roof collapse accidents and functions to optimize and support the design of roadways in underground coalmines. However, traditional monitoring measures, such as using mechanical extensometers or electronic gauges, either require arduous underground labor or cannot function properly in the harsh underground environment. Therefore, in this paper, in order to break through this technological barrier, a novel monitoring system for roof safety control in underground coal mining, using fiber Bragg grating (FBG material as a perceived element and transmission medium, has been developed. Compared with traditional monitoring equipment, the developed, novel monitoring system has the advantages of providing accurate, reliable, and continuous online monitoring of roof activities in underground coal mining. This is expected to further enable the prevention of catastrophic roof collapse accidents. The system has been successfully implemented at a deep hazardous roadway in Zhuji Coal Mine, China. Monitoring results from the study site have demonstrated the advantages of FBG-based sensors over traditional monitoring approaches. The dynamic impacts of progressive face advance on roof displacement and stress have been accurately captured by the novel roadway roof activity and safety monitoring system, which provided essential references for roadway support and design of the mine.

  17. A guidebook for insulated low-slope roof systems. IEA Annex 19, Low-slope roof systems: International Energy Agency Energy Conservation in Buildings and Community Systems Programme

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    Low-slope roof systems are common on commercial and industrial buildings and, to a lesser extent, on residential buildings. Although insulating materials have nearly always been a component of low-slope roofs, the amount of insulation used has increased in the past two decades because of escalation of heating and cooling costs and increased awareness of the need for energy conservation. As the amount of insulation has increased, the demand has intensified for design, installation, and maintenance information specifically for well-insulated roofs. Existing practices for design, installation, and maintenance of insulated roofs have evolved from experience. Typically, these practices feature compromises due to the different properties of materials making up a given roof system. Therefore, they should be examined from time to time to ensure that they are appropriate as new materials continue to enter the market and as the data base on existing systems expands. A primary purpose of this International Energy Agency (IEA) study is to assess current roofing insulation practices in the context of an accumulating data base on performance.

  18. Wind loads on solar energy roofs

    NARCIS (Netherlands)

    Geurts, C.P.W.; Bentum, C.A. van

    2007-01-01

    This paper presents an overview of the wind loads on roofs, equipped with solar energy products, so called Active Roofs. Values given in this paper have been based on wind tunnel and full scale measurements, carried out at TNO, and on an interpretation of existing rules and guidelines. The results

  19. Do green roofs cool the air?

    NARCIS (Netherlands)

    Solcerova, A.; van de Ven, F.H.M.; Wang, Mengyu; Rijsdijk, Michiel; van de Giesen, N.C.

    2017-01-01

    Rapid urbanization and an increasing number and duration of heat waves poses a need to mitigate extremely high temperatures. One of the repeatedly suggested measures to moderate the so called urban heat island are green roofs. This study investigates several extensive sedum-covered green roofs in

  20. Flat roofs, a grey area; Grauzone Flachdach

    Energy Technology Data Exchange (ETDEWEB)

    Riedel, Anja

    2012-11-01

    The boom of low-ballast assembly systems for flat roofs is going on. Solar assembly racks are set up directly on the sealing foil without fastening bolts. But what happens in case of water ingress? And what should be done to prevent damage to the roof cover? (orig.)

  1. Realistic roofs over a rectilinear polygon

    KAUST Repository

    Ahn, Heekap; Bae, Sangwon; Knauer, Christian; Lee, Mira; Shin, Chansu; Vigneron, Antoine E.

    2013-01-01

    Given a simple rectilinear polygon P in the xy-plane, a roof over P is a terrain over P whose faces are supported by planes through edges of P that make a dihedral angle π/4 with the xy-plane. According to this definition, some roofs may have faces

  2. Generating realistic roofs over a rectilinear polygon

    KAUST Repository

    Ahn, Heekap; Bae, Sangwon; Knauer, Christian; Lee, Mira; Shin, Chansu; Vigneron, Antoine E.

    2011-01-01

    Given a simple rectilinear polygon P in the xy-plane, a roof over P is a terrain over P whose faces are supported by planes through edges of P that make a dihedral angle π/4 with the xy-plane. In this paper, we introduce realistic roofs by imposing

  3. Optimal design of three-dimensional structures for roofs Diseño óptimo de estructuras tridimensionales para techos

    Directory of Open Access Journals (Sweden)

    Maximino Tapia Rodriguez

    2012-11-01

    Full Text Available Se presenta un laboratorio virtual que realiza el análisis, diseño y optimización de estructuras de acero rolado en frío, así como la cuantificación de los materiales utilizados en la construcción de la techumbre completa y el costo de fabricación e instalación la misma. El software está dotado con una interfaz de usuario amigable desarrollado para la empresa “Tejas El Águila”. El análisis estructural considera cargas de peso propio, muertas y vivas, a las que estará sometida la estructura en condiciones de servicio, además de considerarse los efectos de viento y sismo para la República Mexicana -de acuerdo a la normatividad vigente. El optimizador está basado en métodos de minimización de entropía con restricciones múltiples, evaluando cada una de las estructuras por el método de la rigidez. Para la evaluación de la eficiencia de la estructura, se utiliza la normativa American Iron and Steel Institute- Allowable Stress Design (AISI-ASD. La optimización de las estructuras se realiza haciendo múltiples evaluaciones de diferentes configuraciones de las mismas, tarea que se ha paralelizado utilizando técnicas de programación de memoria compartidaOpen Multiprocessing (OpenMP. La combinación adecuada del seguimiento de las normatividades vigentes, la implementación del optimizador y los métodos matriciales para el cálculo de estructuras, aunado al ambiente grafico fácil de usar y amigable, han resultado en un potente software que genera soluciones de vivienda económicas, seguras y estéticas (favoreciendo así a un amplio sector de la sociedad mexicana.Se presenta un laboratorio virtual que realiza el análisis, diseño y optimización de estructuras de acero rolado en frío, así como la cuantificación de los materiales utilizados en la construcción de la techumbre completa y el costo de fabricación e instalación la misma. El software está dotado con una interfaz de usuario amigable desarrollado para la

  4. Habitat connectivity and local conditions shape taxonomic and functional diversity of arthropods on green roofs.

    Science.gov (United States)

    Braaker, Sonja; Obrist, Martin Karl; Ghazoul, Jaboury; Moretti, Marco

    2017-05-01

    by specific trait assemblages. The study also provides details on the environmental conditions that influence arthropod diversity and gives new perspectives on how the design of green roofs can be improved to increase their ecological value. Furthermore, the study highlights the importance of integrating green roofs in planning policies which aim to enhance urban habitat connectivity. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  5. Thermal performance of an innovative roof component

    Energy Technology Data Exchange (ETDEWEB)

    Dimoudi, A. [Department of Environmental Engineering, Democritus University of Thrace, Vassilisis Sofias 12, 67 100 Xanthi (Greece); Lykoudis, S. [Institute for Environmental Research and Sustainable Development, National Observatory of Athens, I. Metaxa and B. Pavlou, 152 36 Penteli (Greece); Androutsopoulos, A. [Buildings Department, Division of Energy Efficiency, Centre for Renewable Energy Sources (CRES), 19th km Marathonos Aven., 190 09 Pikermi (Greece)

    2006-11-15

    In this paper, the thermal performance of a ventilated roof component is investigated during the winter period. The ventilated roof component consists of a conventional roof structure - reinforced concrete with a layer of thermal insulation - an air gap that allows the movement of the ambient air and an external layer made of a prefabricated concrete slab. The experimental results of the ventilated roof component during the winter period are presented and its thermal performance is analysed. The effect of key construction parameters like the height of the air gap and the use of a radiant barrier in the air gap is also investigated. Analysis of the results showed that the performance of a ventilated roof component is comparable to a conventional structure during winter. The ventilated component is shown to be in compliance with Greek regulatory requirements in terms of U-value. (author)

  6. Thermal insulation performance of green roof systems

    Energy Technology Data Exchange (ETDEWEB)

    Celik, Serdar; Morgan, Susan; Retzlaff, William; Once, Orcun [southern Illinois University (United States)], e-mail: scelik@siue.edu, e-mail: smorgan@siue.edu, e-mail: wretzla@siue.edu, e-mail: oonce@siue.edu

    2011-07-01

    With the increasing costs of energy, good building insulation has become increasingly important. Among existing insulation techniques is the green roof system, which consists of covering the roof of a building envelop with plants. The aim of this paper is to assess the impact of vegetation type and growth media on the thermal performance of green roof systems. Twelve different green roof samples were made with 4 different growth media and 3 sedum types. Temperature at the sample base was recorded every 15 minutes for 3 years; the insulation behavior was then analysed. Results showed that the insulation characteristics were achieved with a combination of haydite and sedum sexangulare. This study demonstrated that the choice of growth media and vegetation is important to the green roof system's performance; further research is required to better understand the interactions between growth media and plant roots.

  7. The urban wind energy potential for integrated roof wind energy systems based on local building height distributions

    NARCIS (Netherlands)

    Blok, R.; Coers, M.D.

    2017-01-01

    An Integrated Roof Wind Energy System (IRWES) is a roof mounted structure with an internal wind turbine that uses smart aerodynamics to catch and accelerate wind flow. It has been designed for application on (existing) buildings in the urban environment. To estimate the maximum total wind energy

  8. Sheffield's Green Roof Forum: a multi-stranded programme of green roof infrastructure development for the UK's greenest city

    Energy Technology Data Exchange (ETDEWEB)

    Dunnett, N. [Univ. of Sheffield, Western Bank, Sheffield (United Kingdom). Dept. of Landscape

    2006-07-01

    Sheffield, United Kingdom (UK) was the world centre for the steel and cutlery industries. However, those industries have been in decline and the city has been in the process of re-inventing itself over the past 20 years. Sheffield is now known as the UK's greenest city in terms of the amount of woodland, parkland and open spaces within its city limits. The city of Sheffield has also developed a unique partnership approach to promote green roof infrastructure as the most visible and high-profile signal of intent and symbol of low environmental impact building design and construction. This partnership involves Sheffield's Green Roof Forum, comprising the University of Sheffield's multi-disciplinary centre of excellence in green roof research; Sheffield City Council; Groundwork Sheffield, an urban economic and environmental regeneration agency; and city Architects and developers. This partnership meets six times a year to raise the profile of green roofs within the city and region, and to develop strategies to increase the uptake and implementation of green roof infrastructure in the region. This paper discussed the partnership, the Green Room Forum, accomplishments to date in promoting green roofs in the city, and the strategy for the Sheffield region to become a leader in green roof implementation and associated green technologies. The strategy is presented in two parts: consultation and research to identify the nature of market failure and devising methods to overcome that failure. The green roof strategy is being implemented through a program entitled Building Greener, Building Smarter and consists of four inter-linked strands. These strands were discussed in detail and included getting buy-in, demonstrating benefit, establishing the business case, and changing plans and practices. 3 tabs., 1 ref.

  9. Aircraft-crash-protected steel reactor building roof structure for the European market

    International Nuclear Information System (INIS)

    Posta, B.A.; Kadar, I.; Rao, A.S.

    1996-01-01

    This paper recommends the use of all steel roof structures for the reactor building of European Boiling Water Reactor (BWR) plants. This change would make the advanced US BWR designs more compatible with European requirements. Replacement of the existing concrete roof slab with a sufficiently thick steel plate would eliminate the concrete spelling resulting from a postulated aircraft crash, potentially damaging the drywell head or the spent fuel pool

  10. Green roof impact on the hydrological cycle components

    Science.gov (United States)

    Lamera, Carlotta; Rulli, Maria Cristina; Becciu, Gianfranco; Rosso, Renzo

    2013-04-01

    In the last decades the importance of storm water management in urban areas has increased considerably, due to both urbanization extension and to a greater concern for environment pollution. Traditional storm water control practices, based on the "all to the sewer" attitude, rely on conveyance to route storm water runoff from urban impervious surfaces towards the nearby natural water bodies. In recent years, infiltration facilities are receiving an increasing attention, due to their particular efficiency in restoring a balance in hydrological cycle quite equal to quite pre-urbanization condition. In particular, such techniques are designed to capture, temporarily retain and infiltrate storm water, promote evapotranspiration and harvest water at the source, encouraging in general evaporation, evapotranspiration, groundwater recharge and the re-use of storm water. Green roofs are emerging as an increasingly popular Sustainable Urban Drainage Systems (SUDS) technique for urban storm water management. Indeed, they are able to operate hydrologic control over storm water runoff: they allow a significant reduction of peak flows and runoff volumes collected by drainage system, with a consequent reduction of flooding events and pollution masses discharges by CSO. Furthermore green roofs have a positive influence on the microclimate in urban areas by helping in lower urban air temperatures and mitigate the heat island effect. Last but not least, they have the advantage of improving the thermal insulation of buildings, with significant energy savings. A detailed analysis of the hydrological dynamics, connected both with the characteristics of the climatic context and with the green roof technical design, is essential in order to obtain a full characterization of the hydrologic behavior of a green roof system and its effects on the urban water cycle components. The purpose of this paper is to analysis the hydrological effects and urban benefits of the vegetation cover of a

  11. Quantifying the Lateral Bracing Provided by Standing Steam Roof Systems

    OpenAIRE

    Sorensen, Taylor J.

    2016-01-01

    One of the major challenges of engineering is finding the proper balance between economical and safe. Currently engineers at Nucor Corporation have ignored the additional lateral bracing provided by standing seam roofing systems to joists because of the lack of methods available to quantify the amount of bracing provided. Based on the results of testing performed herein, this bracing is significant, potentially resulting in excessively conservative designs and unnecessary costs. This proje...

  12. Performance of dryland and wetland plant species on extensive green roofs.

    Science.gov (United States)

    MacIvor, J Scott; Ranalli, Melissa A; Lundholm, Jeremy T

    2011-04-01

    Green roofs are constructed ecosystems where plants perform valuable services, ameliorating the urban environment through roof temperature reductions and stormwater interception. Plant species differ in functional characteristics that alter ecosystem properties. Plant performance research on extensive green roofs has so far indicated that species adapted to dry conditions perform optimally. However, in moist, humid climates, species typical of wetter soils might have advantages over dryland species. In this study, survival, growth and the performance of thermal and stormwater capture functions of three pairs of dryland and wetland plant species were quantified using an extensive modular green roof system. Seedlings of all six species were germinated in a greenhouse and planted into green roof modules with 6 cm of growing medium. There were 34 treatments consisting of each species in monoculture and all combinations of wet- and dryland species in a randomized block design. Performance measures were survival, vegetation cover and roof surface temperature recorded for each module over two growing seasons, water loss (an estimate of evapotranspiration) in 2007, and albedo and water capture in 2008. Over two seasons, dryland plants performed better than wetland plants, and increasing the number of dryland species in mixtures tended to improve functioning, although there was no clear effect of species or habitat group diversity. All species had survival rates >75 % after the first winter; however, dryland species had much greater cover, an important indicator of green roof performance. Sibbaldiopsis tridentata was the top performing species in monoculture, and was included in the best treatments. Although dryland species outperformed wetland species, planting extensive green roofs with both groups decreased performance only slightly, while increasing diversity and possibly habitat value. This study provides further evidence that plant composition and diversity can

  13. Green-Roof Effects on Neighborhood Microclimate and Human Thermal Sensation

    Directory of Open Access Journals (Sweden)

    C. Y. Jim

    2013-01-01

    Full Text Available Green roofs have been recognized as an effective sustainable design tool to mitigate urban heat island (UHI effects. Previous studies have identified green-roof benefits in cooling and energy-conservation at the building scale, with limited exploration of the wider influence on neighborhood microclimate and human thermal comfort (HTC. This paper investigated the impacts of community-scale green-roof installation on air temperature and HTC in five typical residential neighborhoods of subtropical Hong Kong. The microclimate models ENVI-met and RayMan permitted studies of two main green-roof scenarios, namely extensive (EGR and intensive (IGR. Microclimatic monitoring data from a local experimental green-roof site validated the modeling methods. The results verified that green-roof cooling effects were not restricted to rooftops, but extended to the ground to improve neighborhood microclimate. EGR reduced pedestrian-level air temperature by 0.4–0.7 °C, and IGR by 0.5–1.7 °C, with maximum effect in open-set low rise sites. Coverage by building footprints and building height dampened lateral and vertical advection of cool air generated by green roofs. Roof greening also improved notably the rooftop-podium level HTC. Diurnal duration of high heat stress was reduced by 6–9 h for EGR scenarios, and 9–11 h for IGR. The findings indicated that large-scale green-roof installation could bring neighborhood-wide cooling, mitigate urban heat island effect, and furnish more comfortable thermal environment for urban residents.

  14. Effectiveness of foam-based and traditional green roofs in reducing nitrogen, phosphorus, organic carbon and suspended solids in urban installations

    Science.gov (United States)

    MacAvoy, S. E.; Mucha, S.; Williamson, G.

    2017-12-01

    While green roofs have well understood benefits for retaining runoff, there is less of a consensus regarding the potential for retaining and absorbing nutrients or suspended solids from roof runoff that would otherwise travel to waterways. Additionally, there are numerous designs, materials and maintenance plans associated with "green" roofs/surfaces that may greatly impact not only their hydrological benefit but also their pollution mitigation potential. Here we examine the NO3, NH4, total organic carbon (TOC), total phosphorus (TP) and total suspended solids (TSS) retention potential from planted and unplanted foam roofs and traditional soil roofs. Direct precipitation, untreated runoff and throughflow from the different roof types were collected for 3 to 11 rain events over a year (depending on roof). Unplanted and traditional roofs reduced TSS by 80% or better relative to runoff. Traditional roofs showed 50% lower TP than runoff or other roof types. TOC was higher than direct precipitation for all treatments, although there were no differences among the treatments themselves. Taken as averages over the 11 events, NO3 and NH4 concentrations were highly variable for runoff and treatments and significant differences were not detected. Preliminary analysis suggests there were no differences between performance of traditional versus foam-based roofs, although a greater sample size is required to be definitive.

  15. Green roof stormwater retention: effects of roof surface, slope, and media depth.

    Science.gov (United States)

    VanWoert, Nicholaus D; Rowe, D Bradley; Andresen, Jeffrey A; Rugh, Clayton L; Fernandez, R Thomas; Xiao, Lan

    2005-01-01

    Urban areas generate considerably more stormwater runoff than natural areas of the same size due to a greater percentage of impervious surfaces that impede water infiltration. Roof surfaces account for a large portion of this impervious cover. Establishing vegetation on rooftops, known as green roofs, is one method of recovering lost green space that can aid in mitigating stormwater runoff. Two studies were performed using several roof platforms to quantify the effects of various treatments on stormwater retention. The first study used three different roof surface treatments to quantify differences in stormwater retention of a standard commercial roof with gravel ballast, an extensive green roof system without vegetation, and a typical extensive green roof with vegetation. Overall, mean percent rainfall retention ranged from 48.7% (gravel) to 82.8% (vegetated). The second study tested the influence of roof slope (2 and 6.5%) and green roof media depth (2.5, 4.0, and 6.0 cm) on stormwater retention. For all combined rain events, platforms at 2% slope with a 4-cm media depth had the greatest mean retention, 87%, although the difference from the other treatments was minimal. The combination of reduced slope and deeper media clearly reduced the total quantity of runoff. For both studies, vegetated green roof systems not only reduced the amount of stormwater runoff, they also extended its duration over a period of time beyond the actual rain event.

  16. Run-off from roofing materials

    International Nuclear Information System (INIS)

    Roed, J.

    1985-01-01

    In order to find the runn-off from roof material, a roof has been constructed with two different slopes (30 deg. and 45 deg.). 7 Be and 137 Cs have been used as tracers. Considering new roof material, the pollution removed by run-off processes has been shown to be very different for various roof materials. The pollution is much more easily removed from silicon-treated material than from porous red-tile roof material. Cesium is removed more easily than beryllium. The content of cesium in old roof materials is greater in red-tile than in other less porous roof materials. However, the measured removal from new material does not correspond to the amount accumulated in the old. This could be explained by weathering and by saturation effects. The last effect is probably the more important. The measurements on old material indicate a removal of 44-86% of cesium pollution by run-off, whereas the measurement on new material showed a removal of only 31-50%. It has been demonstrated that the pollution concentration in run-off water could be very different from that in rainwater

  17. The use of aluminum dome tank roofs

    International Nuclear Information System (INIS)

    Morovich, G.L.

    1992-01-01

    Since the late 1970's the aluminum dome tank roof has gained wide usage for both new and retrofit applications. The increased application for the structure results from a need for maintenance reduction, environmental considerations, concern for product quality and economics. The American Petroleum Institute (API) has approved Standard API 650, Appendix G - Structurally Supported Aluminum Dome Roofs for publication. The aluminum dome was originally used as weather cover for retrofiting external floating roof tanks. The roof was considered for the reduction of maintenance related to draining water from the external floating roofs and problems resulting from freezing of drain lines and snow accumulation. This paper reports that environmental concerns have expanded the value of aluminum dome roofs. Rainwater bypassing the seals of an external floating roof became classified as a hazardous material requiring special and expensive disposal procedures. The marketing terminal facilities typically do not have the capacity for proper treatment of contaminated bottom water. With new fuel additives being water soluble, water contamination not only created a hazardous waste disposal problem, but resulted in reduced product quality

  18. Proven Alternatives for Aboveground Treatment of Arsenic in Groundwater

    Science.gov (United States)

    This issue paper, developed for EPA's Engineering Forum, identifies and summarizes experiences with proven aboveground treatment alternatives for arsenic in groundwater, and provides information on their relative effectiveness and cost.

  19. an expansion of the aboveground biomass quantification model for ...

    African Journals Online (AJOL)

    Research Note BECVOL 3: an expansion of the aboveground biomass quantification model for ... African Journal of Range and Forage Science ... encroachment and estimation of food to browser herbivore species, was proposed during 1989.

  20. Changes in vegetation structure and aboveground biomass in ...

    African Journals Online (AJOL)

    Changes in vegetation structure and aboveground biomass in response to traditional rangeland management practices in Borana, southern Ethiopia. ... managed by prescribed fire for five years and grazed only post-fire during dry seasons.

  1. Above-ground tree outside forest (TOF) phytomass and carbon ...

    Indian Academy of Sciences (India)

    to classify TOF, to estimate above-ground TOF phytomass and the carbon content ... eral, trees outside forests (TOF) mean the trees ..... have been used to stratify the area, based on the ... The optimum plot size and num- .... population centres.

  2. Impact- and earthquake- proof roof structure

    International Nuclear Information System (INIS)

    Shohara, Ryoichi.

    1990-01-01

    Building roofs are constituted with roof slabs, an earthquake proof layer at the upper surface thereof and an impact proof layer made of iron-reinforced concrete disposed further thereover. Since the roofs constitute an earthquake proof structure loading building dampers on the upper surface of the slabs by the concrete layer, seismic inputs of earthquakes to the buildings can be moderated and the impact-proof layer is formed, to ensure the safety to external conditions such as earthquakes or falling accidents of airplane in important facilities such as reactor buildings. (T.M.)

  3. Improving the durability of flat roof constructions

    DEFF Research Database (Denmark)

    Rudbeck, Claus Christian; Svendsen, Sv Aa Højgaard

    1999-01-01

    of the system, thereby making it easier to detect leaks faster. When a leak is detected, the membrane is repaired locally. In order to remove water which has already entered the insulation, an air gap or a system of air channels between the deck and the insulation is subjected to forced ventilation with outdoor...... air. When the water is removed, the ventilation is stopped, and the roofing construction can continue to function as intended.Roofing systems where trapped moisture can be removed are cost-effective compared to traditional roofing insulation systems, and as leakage can be treated, they have a longer...

  4. The Hydrological Performance of Lightweight Green Roofs Made From Recycled Waste Materials As the Drainage Layer

    Directory of Open Access Journals (Sweden)

    Afizah Asman Nurul Shahadahtul

    2017-01-01

    Full Text Available Green roofs can be used for promoting infiltration and provide temporary storage spaces. Hence, in urban stormwater structural design, the investigation of the hydrological performance investigation is often required. Thus, this paper presents the results of a hydrological investigation in term of peak flow reduction and green roof’s weight using 0, 2, and 6% slope for three specimens drainage layer in green roofs. Three types of recycled waste are selected for each test bed which is rubber crumbs, palm oil shell, and polyfoam. Another test bed without a drainage layer as a control. The result indicates that rubber crumbs can be used as a stormwater control and runoff reduction while ensuring a good drainage and aeration of the substrate and roofs. From the results obtained shows that rubber crumbs are suitable as a drainage layer and a proposed slope of 6% are suitable for lightweight green roofs.

  5. The influence of a cubic building on a roof mounted wind turbine

    International Nuclear Information System (INIS)

    Micallef, Daniel; Sant, Tonio; Ferreira, Carlos

    2016-01-01

    The performance of a wind turbine located above a cubic building is not well understood. This issue is of fundamental importance for the design of small scale wind turbines. One variable which is of particular importance in this respect is the turbine height above roof level. In this work, the power performance of a small wind turbine is assessed as a function of the height above the roof of a generic cubic building. A 3D Computational Fluid Dynamics model of a 10m x 10m x 10m building is used with the turbine modelled as an actuator disc. Results have shown an improvement in the average power coefficient even in cases where the rotor is partially located within the roof separation zone. This goes against current notions of small wind turbine power production. This study can be of particular importance to guide the turbine installation height on building roof tops. (paper)

  6. Stress and deflection analyses of floating roofs based on a load-modifying method

    International Nuclear Information System (INIS)

    Sun Xiushan; Liu Yinghua; Wang Jianbin; Cen Zhangzhi

    2008-01-01

    This paper proposes a load-modifying method for the stress and deflection analyses of floating roofs used in cylindrical oil storage tanks. The formulations of loads and deformations are derived according to the equilibrium analysis of floating roofs. Based on these formulations, the load-modifying method is developed to conduct a geometrically nonlinear analysis of floating roofs with the finite element (FE) simulation. In the procedure with the load-modifying method, the analysis is carried out through a series of iterative computations until a convergence is achieved within the error tolerance. Numerical examples are given to demonstrate the validity and reliability of the proposed method, which provides an effective and practical numerical solution to the design and analysis of floating roofs

  7. Timber volume and aboveground live tree biomass estimations for landscape analyses in the Pacific Northwest

    Science.gov (United States)

    Xiaoping Zhou; Miles A. Hemstrom

    2010-01-01

    Timber availability, aboveground tree biomass, and changes in aboveground carbon pools are important consequences of landscape management. There are several models available for calculating tree volume and aboveground tree biomass pools. This paper documents species-specific regional equations for tree volume and aboveground live tree biomass estimation that might be...

  8. 30 CFR 75.213 - Roof support removal.

    Science.gov (United States)

    2010-07-01

    ... mining experience shall perform permanent roof support removal work. (b) Prior to the removal of... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Roof support removal. 75.213 Section 75.213... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Roof Support § 75.213 Roof support removal. (a)(1) All...

  9. 30 CFR 75.206 - Conventional roof support.

    Science.gov (United States)

    2010-07-01

    ... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Roof Support § 75.206 Conventional roof support. (a) Except in anthracite mines using non-mechanized mining systems, when conventional roof support... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Conventional roof support. 75.206 Section 75...

  10. Multifunctionality is affected by interactions between green roof plant species, substrate depth, and substrate type.

    Science.gov (United States)

    Dusza, Yann; Barot, Sébastien; Kraepiel, Yvan; Lata, Jean-Christophe; Abbadie, Luc; Raynaud, Xavier

    2017-04-01

    Green roofs provide ecosystem services through evapotranspiration and nutrient cycling that depend, among others, on plant species, substrate type, and substrate depth. However, no study has assessed thoroughly how interactions between these factors alter ecosystem functions and multifunctionality of green roofs. We simulated some green roof conditions in a pot experiment. We planted 20 plant species from 10 genera and five families (Asteraceae, Caryophyllaceae, Crassulaceae, Fabaceae, and Poaceae) on two substrate types (natural vs. artificial) and two substrate depths (10 cm vs. 30 cm). As indicators of major ecosystem functions, we measured aboveground and belowground biomasses, foliar nitrogen and carbon content, foliar transpiration, substrate water retention, and dissolved organic carbon and nitrates in leachates. Interactions between substrate type and depth strongly affected ecosystem functions. Biomass production was increased in the artificial substrate and deeper substrates, as was water retention in most cases. In contrast, dissolved organic carbon leaching was higher in the artificial substrates. Except for the Fabaceae species, nitrate leaching was reduced in deep, natural soils. The highest transpiration rates were associated with natural soils. All functions were modulated by plant families or species. Plant effects differed according to the observed function and the type and depth of the substrate. Fabaceae species grown on natural soils had the most noticeable patterns, allowing high biomass production and high water retention but also high nitrate leaching from deep pots. No single combination of factors enhanced simultaneously all studied ecosystem functions, highlighting that soil-plant interactions induce trade-offs between ecosystem functions. Substrate type and depth interactions are major drivers for green roof multifunctionality.

  11. Cost Effectiveness of Precast Reinforced Concrete Roof Slabs

    Science.gov (United States)

    Parskiy, N. D.; Molodtsov, M. V.; Molodtsova, V. E.

    2017-11-01

    Engineers always seek to free interior space from intermediate supporting elements. Nowadays plants, being at the forefront of technology, produce a new generation of exclusive patented prefabricated reinforced concrete elements with a high load-bearing capacity, excellent heat resistance characteristics combined with the aesthetics and beauty. It is a system of Seagull Gabbiano prestressed roof slabs for the spans of 12m - 40m. The article shows the advantages of the Seagull slabs over conventional precast reinforced concrete and metal roof trusses. It also gives the analysis of the technical and economic indices of design and construction of a building with the Seagull slabs depending on the size of spans to cover. The use of structural systems with increased spans allows for the modern buildings and structures of prefabricated reinforced concrete with enhanced functionality and aesthetics alongside with a wide range of planning solutions.

  12. Thermophysical aspects of reconstruction of cold roof spaces

    Directory of Open Access Journals (Sweden)

    Semko Oleksandr

    2017-01-01

    Full Text Available The results of theoretical studies of thermal modernization of cold roof floor. The designs of overlap of long-life roofs of public buildings were considered. Overlap of these buildings are made by wooden or concrete beams and made of concrete slabs with upward edges. The problems of thermal modernization of these designs are consideration of the impact of heat-conducting inclusions on the resistance to heat. The heat-conducting inclusions of constructions are beams and vertical edges of the slabs. The results of calculations of the temperature fields were used for the analysis. The research was carried for the two temperature zones which Ukraine’s territory is divided into. The analysis of thermal protection level of structures overlap was made. The magnitude of the impact of heat-conducting inclusions on resistance to heat after thermal modernization of cold roof floor was observed. The analysis showed that the thermal protection properties of structures less than standard, therefore the insulation of areas with heat-conducting inclusions is required. The options of insulation of these areas were considered. The optimal insulation options with the least amount of additional insulation over the heat conductive areas were selected.

  13. Innovative Ballasted Flat Roof Solar PV Racking System

    Energy Technology Data Exchange (ETDEWEB)

    Peek, Richard T. [Cascade Engineering, Grand Rapids, MI (United States)

    2014-12-15

    The objective of this project was to reduce the cost of racking for PV solar on flat commercial rooftops. Cost reductions would come from both labor savings and material savings related to the installation process. The rack would need to accommodate the majority of modules available on the market. Cascade Engineering has a long history of converting traditional metal type applications over to plastic. Injection molding of plastics have numerous advantages including selection of resin for the application, placing the material exactly where it is needed, designing in features that will speed up the installation process, and weight reduction of the array. A plastic rack would need to meet the requirements of UL2703, Mounting systems, mounting devices, clamping/retention devices, and ground lugs for use with flat-plate photovoltaic modules and panels. Comparing original data to the end of project racking design, racking material costs were reduced 50% and labor costs reduced 64%. The racking product accommodates all 60 and 72 cell panels on the market, meets UL2703 requirements, contributes only 1.3 pounds per square foot of weight to the array, requires little ballast to secure the array, automatically grounds the module when the module is secured, stacks/nests well for shipping/fewer lifts to the roof, provides integrated wire routing, allows water to drain on the roof, and accommodates various seismic roof connections. Project goals were achieved as noted in the original funding application.

  14. Evaluation and Optimization of a Traditional North-Light Roof on Industrial Plant Energy Consumption

    Energy Technology Data Exchange (ETDEWEB)

    Adriaenssens, Sigrid [Form-Finding Lab, Department of Civil and Environmental Engineering, School of Engineering and Applied Science, Princeton Univ., NJ (United States); Hao Liu [Center for Intelligent and Networked Systems, Department of Automation, Tsinghua National Laboratory for Information Science and Technology, Tsinghua University, Beijing (China); Wahed, Miriam [Form-Finding Lab, Department of Civil and Environmental Engineering, School of Engineering and Applied Science, Princeton Univ., NJ (United States); Qianchuan Zhao [Center for Intelligent and Networked Systems, Department of Automation, Tsinghua National Laboratory for Information Science and Technology, Tsinghua University, Beijing (China)

    2013-04-15

    Increasingly strict energy policies, rising energy prices, and a desire for a positive corporate image currently serve as incentives for multinational corporations to reduce their plants’ energy consumption. This paper quantitatively investigates and discusses the value of a traditional north-light roof using a complete building energy simulation and optimization framework. The findings indicate that the north-light system yields positive building energy performance for several climate zones, including: (i) Humid Subtropical; (ii) Semiarid Continental; (iii) Mediterranean; and (iv) Subtropical Highland. In the Subtropical Highland climate zone, for example, the building energy consumption of a north-light roof is up to 54% less than that of a conventional flat roof. Based on these positive findings, this paper further presents an optimization framework that alters the north-light roof shape to further improve its energy performance. To quantitatively guarantee a high probability of finding satisfactory designs while reducing the computational processing time, ordinal optimization is introduced into the scheme. The Subtropical Highland case study shows further energy building consumption reduction of 26% for an optimized north-light roof shape. The presented evaluation and optimization framework could be used in designing a plant with integrated north-lights roof that aim at energy efficiency while maintaining environmental occupant comfort levels.

  15. A two-stage storage routing model for green roof runoff detention.

    Science.gov (United States)

    Vesuviano, Gianni; Sonnenwald, Fred; Stovin, Virginia

    2014-01-01

    Green roofs have been adopted in urban drainage systems to control the total quantity and volumetric flow rate of runoff. Modern green roof designs are multi-layered, their main components being vegetation, substrate and, in almost all cases, a separate drainage layer. Most current hydrological models of green roofs combine the modelling of the separate layers into a single process; these models have limited predictive capability for roofs not sharing the same design. An adaptable, generic, two-stage model for a system consisting of a granular substrate over a hard plastic 'egg box'-style drainage layer and fibrous protection mat is presented. The substrate and drainage layer/protection mat are modelled separately by previously verified sub-models. Controlled storm events are applied to a green roof system in a rainfall simulator. The time-series modelled runoff is compared to the monitored runoff for each storm event. The modelled runoff profiles are accurate (mean Rt(2) = 0.971), but further characterization of the substrate component is required for the model to be generically applicable to other roof configurations with different substrate.

  16. Metal and nutrient dynamics on an aged intensive green roof.

    Science.gov (United States)

    Speak, A F; Rothwell, J J; Lindley, S J; Smith, C L

    2014-01-01

    Runoff and rainfall quality was compared between an aged intensive green roof and an adjacent conventional roof surface. Nutrient concentrations in the runoff were generally below Environmental Quality Standard (EQS) values and the green roof exhibited NO3(-) retention. Cu, Pb and Zn concentrations were in excess of EQS values for the protection of surface water. Green roof runoff was also significantly higher in Fe and Pb than on the bare roof and in rainfall. Input-output fluxes revealed the green roof to be a potential source of Pb. High concentrations of Pb within the green roof soil and bare roof dusts provide a potential source of Pb in runoff. The origin of the Pb is likely from historic urban atmospheric deposition. Aged green roofs may therefore act as a source of legacy metal pollution. This needs to be considered when constructing green roofs with the aim of improving pollution remediation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Roof instability characteristics and pre-grouting of the roof caving zone in residual coal mining

    Science.gov (United States)

    Zhao, Tong; Liu, Changyou

    2017-12-01

    Abandoned roadways and roof caving zones are commonly found in residual coal, and can destroy the integrity of the coal seam and roof. Resulting from mining-induced stress, continuous collapse and fracture instability in roof caving zones (RCZs) jeopardize the safety and efficiency of residual coal mining. Based on the engineering geology conditions of remining face 3101 in Shenghua Mine, the roof fracture and instability features of the RCZ were analyzed through physical simulation, theoretical analysis, and field measurements. In this case, influenced by the RCZ, the main roof across the RCZ fractured and rotated towards the goaf, greatly increasing the working resistance, and crushing the supports. The sudden instability of the coal pillars weakened its support of the main roof, thus resulting in long-key blocks across the RCZ and hinged roof structures, which significantly decreased the stability of the underlying immediate roof. This study establishes a mechanical model for the interactions between the surrounding rock and the supports in the RCZ, determines the reasonable working resistance, and examines the use of pre-grouting solidification restoration technology (PSRT) to solidify the RCZ and reinforce the coal pillars—thus increasing their bearing capacity. Field measurements revealed no roof flaking, inhomogeneous loading or support crushing, indicating that the PSRT effectively controlled the surrounding rock of the RCZ.

  18. ROOF GARDENS AS LANDSCAPING IN MODERN TIMES

    Directory of Open Access Journals (Sweden)

    Vaska Sandeva

    2017-02-01

    Full Text Available As we know we live in a process of industrialization and massive building of residential buildings, both individually and as a collective housing. Given all that happens even with the procedural other things to come up with all this, the country remains less green space that is required for a single environment, so the roof gardens are the best choice for all of this to get a beautiful country. For roof gardens should be given the explanation that, roof gardens, call it beautiful, flat roofs, and with gentle slope, with rich composition intensively maintained and often impose a constructive adaptation of the building and benefits by the architectural beauty, insulation, absorption. Commonly found in urban areas and almost always are placed foliage with not very high growth.

  19. Certified ecological roofs; Oekologisch mit Praedikat

    Energy Technology Data Exchange (ETDEWEB)

    Haslinger, Rupert

    2012-08-02

    Roofs of farm buildings are optimally suited for photovoltaic power supplies. Reimbursement for grid power supply is one interesting aspects, but electric power produced on site can also be used directly in agriculture and especially in viniculture.

  20. Performance Evaluation of Advanced Retrofit Roof Technologies Using Field-Test Data Phase Three Final Report, Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Kaushik [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Childs, Phillip W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atchley, Jerald Allen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    This article presents some miscellaneous data from two low-slope and two steep-slope experimental roofs. The low-slope roofs were designed to compare the performance of various roof coatings exposed to natural weatherization. The steep-slope roofs contained different combinations of phase change material, rigid insulation, low emittance surface and above-sheathing ventilation, with standing-seam metal panels on top. The steep-slope roofs were constructed on a series of adjacent attics separated at the gables using thick foam insulation. This article describes phase three (3) of a study that began in 2009 to evaluate the energy benefits of a sustainable re-roofing technology utilizing standing-seam metal roofing panels combined with energy efficient features like above-sheathing-ventilation (ASV), phase change material (PCM) and rigid insulation board. The data from phases 1 and 2 have been previously published and reported [Kosny et al., 2011; Biswas et al., 2011; Biswas and Childs, 2012; Kosny et al., 2012]. Based on previous data analyses and discussions within the research group, additional test roofs were installed in May 2012, to test new configurations and further investigate different components of the dynamic insulation systems. Some experimental data from phase 3 testing from May 2012 to December 2013 and some EnergyPlus modeling results have been reported in volumes 1 and 3, respectively, of the final report [Biswas et al., 2014; Biswas and Bhandari, 2014].

  1. Global developments of controls of powered roof supports

    Energy Technology Data Exchange (ETDEWEB)

    Das, S.K. [Indian School of Mines, Dhanbad (India). Centre of Longwall Mine Mechanisation

    1996-04-01

    The efficiency of hydraulic powered roof support systems mainly depends upon the efficient control and operation of hydraulic valves and their associated accessories. From 1961 to 1994 tremendous efforts had been made for the development of higher and higher efficient, reliable but simpler control systems starting from the manual hydraulic to electro-hydraulic and finally computer based electronic control system. A global survey of development of various types and design of control systems of powered roof supports has been made and many of them are highlighted in the paper for making this work a small emblem regarding the efforts of development of the controls of powered roof support systems by the global engineers of the 20th century. Many of the control systems are no longer in use and have totally vanished from this earth and many more control systems including their literatures may vanish from this world in the coming decades. This work may give a guideline regarding the selection of right type of control systems for the powered supports in future. 14 refs., 6 figs.

  2. The Impact of Roof Pitch and Ceiling Insulation on Cooling Load of Naturally-Ventilated Attics

    Directory of Open Access Journals (Sweden)

    Linxia Gu

    2012-07-01

    Full Text Available A 2D unsteady computational fluid dynamics (CFD model is employed to simulate buoyancy-driven turbulent ventilation in attics with different pitch values and ceiling insulation levels under summer conditions. The impacts of roof pitch and ceiling insulation on the cooling load of gable-roof residential buildings are investigated based on the simulation of turbulent air flow and natural convection heat transfer in attic spaces with roof pitches from 3/12 to 18/12 combined with ceiling insulation levels from R-1.2 to R-40. The modeling results show that the air flows in the attics are steady and exhibit a general streamline pattern that is qualitatively insensitive to the investigated variations of roof pitch and ceiling insulation. Furthermore, it is predicted that the ceiling insulation plays a control role on the attic cooling load and that an increase of roof pitch from 3/12 to 8/12 results in a decrease in the cooling load by around 9% in the investigated cases. The results suggest that the increase of roof pitch alone, without changing other design parameters, has limited impact on attics cooling load and airflow pattern. The research results also suggest both the predicted ventilating mass flow rate and attic cooling load can be satisfactorily correlated by simple relationships in terms of appropriately defined Rayleigh and Nusselt numbers.

  3. Evaluation of green roof as green technology for urban stormwater quantity and quality controls

    International Nuclear Information System (INIS)

    Kok, K H; Sidek, L M; Basri, H; Muda, Z C; Beddu, S; Abidin, M R Z

    2013-01-01

    Promoting green design, construction, reconstruction and operation of buildings has never been more critical than now due to the ever increasing greenhouse gas emissions and rapid urbanizations that are fuelling climate change more quickly. Driven by environmental needs, Green Building Index (GBI) was founded in Malaysia to drive initiative to lead the property industry towards becoming more environment-friendly. Green roof system is one of the assessment criteria of this rating system which is under category of sustainable site planning and management. An extensive green roof was constructed in Humid Tropics Center (HTC) Kuala Lumpur as one of the components for Stormwater Management Ecohydrology (SME) in order to obtain scientific data of the system. This paper evaluates the performance of extensive green roof at Humid Tropics Center with respect to urban heat island mitigation and stormwater quantity and quality controls. Findings indicate that there was a reduction of around 1.5°C for indoor temperature of the building after installation of green roof. Simulations showed that the peak discharge was reduced up to 24% relative to impervious brown roof. The results show an increment of pH and high concentration of phosphate for the runoff generated from the green roof and the runoff water quality ranged between class I and II under INWQS.

  4. Analysis of DOE s Roof Savings Calculator with Comparison to other Simulation Engines

    Energy Technology Data Exchange (ETDEWEB)

    New, Joshua Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Huang, Yu [White Box Technologies, Salt Lake City, UT (United States); Levinson, Ronnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mellot, Joe [The Garland Company, Cleveland, OH (United States); Sanyal, Jibonananda [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Childs, Kenneth W [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-01-01

    A web-based Roof Savings Calculator (RSC) has been deployed for the Department of Energy as an industry-consensus tool to help building owners, manufacturers, distributors, contractors and researchers easily run complex roof and attic simulations. This tool employs the latest web technologies and usability design to provide an easy input interface to an annual simulation of hour-by-hour, whole-building performance using the world-class simulation tools DOE-2.1E and AtticSim. Building defaults were assigned based on national averages and can provide estimated annual energy and cost savings after the user selects nothing more than building location. In addition to cool reflective roofs, the RSC tool can simulate multiple roof and attic configurations including different roof slopes, above sheathing ventilation, radiant barriers, low-emittance surfaces, HVAC duct location, duct leakage rates, multiple layers of building materials, ceiling and deck insulation levels, and other parameters. A base case and energy-efficient alternative can be compared side-by-side to generate an energy/cost savings estimate between two buildings. The RSC tool was benchmarked against field data for demonstration homes in Ft. Irwin, CA. However, RSC gives different energy savings estimates than previous cool roof simulation tools so more thorough software and empirical validation proved necessary. This report consolidates much of the preliminary analysis for comparison of RSC s projected energy savings to that from other simulation engines.

  5. Evaluation of green roof as green technology for urban stormwater quantity and quality controls

    Science.gov (United States)

    Kok, K. H.; Sidek, L. M.; Abidin, M. R. Z.; Basri, H.; Muda, Z. C.; Beddu, S.

    2013-06-01

    Promoting green design, construction, reconstruction and operation of buildings has never been more critical than now due to the ever increasing greenhouse gas emissions and rapid urbanizations that are fuelling climate change more quickly. Driven by environmental needs, Green Building Index (GBI) was founded in Malaysia to drive initiative to lead the property industry towards becoming more environment-friendly. Green roof system is one of the assessment criteria of this rating system which is under category of sustainable site planning and management. An extensive green roof was constructed in Humid Tropics Center (HTC) Kuala Lumpur as one of the components for Stormwater Management Ecohydrology (SME) in order to obtain scientific data of the system. This paper evaluates the performance of extensive green roof at Humid Tropics Center with respect to urban heat island mitigation and stormwater quantity and quality controls. Findings indicate that there was a reduction of around 1.5°C for indoor temperature of the building after installation of green roof. Simulations showed that the peak discharge was reduced up to 24% relative to impervious brown roof. The results show an increment of pH and high concentration of phosphate for the runoff generated from the green roof and the runoff water quality ranged between class I and II under INWQS.

  6. Remediation and recycling of oil-contaminated soil beneath a large above-ground storage tank

    International Nuclear Information System (INIS)

    Wallace, G.

    1994-01-01

    While retrofitting a large 30-year-old, above-ground petroleum storage tank, Southern California Edison Company (SCE) discovered that soil beneath the fixed-roof, single-bottom tank was contaminated with 40,000 gallons of number-sign 6 fuel oil. The steel tank was left in place during the excavation and remediation of the contaminated soil to retain the operating permit. The resulting 2,000 tons of contaminated aggregate was recycled to make asphalt concrete for paving the tank basin and the remaining 5,600 tons of oily soil was thermally treated on site for use as engineered fill at another location. This successful operation provided an economical cleanup solution for a common leakage problem of single-lined tanks and eliminated the long-term liability of Class 1 landfill disposal. As a pro-active environmental effort, this paper shares SCE's site assessment procedure, reveals the engineering method developed to stabilize the tank, discusses the soil treatment technologies used, describes the problems encountered and lessons learned during the cleanup, discloses the costs of the operation, and offers guidelines and recommendations for similar tank remediation. This paper does not describe the work or costs for removing or replacing the tank bottom

  7. Fuel consumption impacts of auto roof racks

    International Nuclear Information System (INIS)

    Chen, Yuche; Meier, Alan

    2016-01-01

    The after-market roof rack is one of the most common components attached to a vehicle for carrying over-sized items, such as bicycles and skis. It is important to understand these racks’ fuel consumption impacts on both individual vehicles and the national fleet because they are widely used. We estimate the national fuel consumption impacts of roof racks using a bottom-up approach. Our model incorporates real-world data and vehicle stock information to enable assessing fuel consumption impacts for several categories of vehicles, rack configurations, and usage conditions. In addition, the model draws on two new data-gathering techniques, on-line forums and crowd-sourcing. The results show that nationwide, roof racks are responsible for 0.8‰ of light duty vehicle fuel consumption in 2015, corresponding to 100 million gallons of gasoline per year. Sensitivity analyses show that results are most sensitive to the fraction of vehicles with installed roof racks but carrying no equipment. The aerodynamic efficiency of typical roof racks can be greatly improved and reduce individual vehicle fuel consumption; however, government policies to minimize extensive driving with empty racks—if successful—could save more fuel nationally. - Highlights: •First estimate of national energy impacts of auto roof racks—about 1‰. •A bottom-up approach reveals details of the fuel consumption penalty caused by racks. •Two novel data collection techniques, on-line forums and crowd-sourcing, improve estimate. •Technical and behavioral policies could significantly cut fuel penalties from roof racks.

  8. Research on the compressive strength of a passenger vehicle roof

    Science.gov (United States)

    Zhao, Guanglei; Cao, Jianxiao; Liu, Tao; Yang, Na; Zhao, Hongguang

    2017-05-01

    To study the compressive strength of a passenger vehicle roof, this paper makes the simulation test on the static collapse of the passenger vehicle roof and analyzes the stress and deformation of the vehicle roof under pressure in accordance with the Roof Crush Resistance of Passenger Cars (GB26134-2010). It studies the optimization on the major stressed parts, pillar A, pillar B and the rail of roof, during the static collapse process of passenger vehicle roof. The result shows that the thickness of pillar A and the roof rail has significant influence on the compressive strength of the roof while that of pillar B has minor influence on the compressive strength of the roof.

  9. Adaptive fluid lens and sunlight redirection system : exploring a novel way of redirecting and altering sunlight in large span roofs

    NARCIS (Netherlands)

    Heinzelmann, F.; Bristogianni, T.; Teuffel, P.; Stouffs, R.; Sariyildiz, S.

    2013-01-01

    The paper describes a novel system to alter and redirect sunlight under large span roofs with the help of a fluid lens system. Focus lies on the computational design, testing, measurement and evaluation of the performance of a physical prototype.

  10. MODIS Based Estimation of Forest Aboveground Biomass in China

    Science.gov (United States)

    Sun, Yan; Wang, Tao; Zeng, Zhenzhong; Piao, Shilong

    2015-01-01

    Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS) dataset in a machine learning algorithm (the model tree ensemble, MTE). We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha−1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y−1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y−1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y−1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests. PMID:26115195

  11. MODIS Based Estimation of Forest Aboveground Biomass in China.

    Science.gov (United States)

    Yin, Guodong; Zhang, Yuan; Sun, Yan; Wang, Tao; Zeng, Zhenzhong; Piao, Shilong

    2015-01-01

    Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS) dataset in a machine learning algorithm (the model tree ensemble, MTE). We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha-1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y-1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y-1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y-1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests.

  12. MODIS Based Estimation of Forest Aboveground Biomass in China.

    Directory of Open Access Journals (Sweden)

    Guodong Yin

    Full Text Available Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS dataset in a machine learning algorithm (the model tree ensemble, MTE. We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha-1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y-1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y-1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y-1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests.

  13. Green roof valuation: a probabilistic economic analysis of environmental benefits.

    Science.gov (United States)

    Clark, Corrie; Adriaens, Peter; Talbot, F Brian

    2008-03-15

    Green (vegetated) roofs have gained global acceptance as a technologythat has the potential to help mitigate the multifaceted, complex environmental problems of urban centers. While policies that encourage green roofs exist atthe local and regional level, installation costs remain at a premium and deter investment in this technology. The objective of this paper is to quantitatively integrate the range of stormwater, energy, and air pollution benefits of green roofs into an economic model that captures the building-specific scale. Currently, green roofs are primarily valued on increased roof longevity, reduced stormwater runoff, and decreased building energy consumption. Proper valuation of these benefits can reduce the present value of a green roof if investors look beyond the upfront capital costs. Net present value (NPV) analysis comparing a conventional roof system to an extensive green roof system demonstrates that at the end of the green roof lifetime the NPV for the green roof is between 20.3 and 25.2% less than the NPV for the conventional roof over 40 years. The additional upfront investment is recovered at the time when a conventional roof would be replaced. Increasing evidence suggests that green roofs may play a significant role in urban air quality improvement For example, uptake of N0x is estimated to range from $1683 to $6383 per metric ton of NOx reduction. These benefits were included in this study, and results translate to an annual benefit of $895-3392 for a 2000 square meter vegetated roof. Improved air quality leads to a mean NPV for the green roof that is 24.5-40.2% less than the mean conventional roof NPV. Through innovative policies, the inclusion of air pollution mitigation and the reduction of municipal stormwater infrastructure costs in economic valuation of environmental benefits of green roofs can reduce the cost gap that currently hinders U.S. investment in green roof technology.

  14. Comparative Assessment of Thermal Performance of Existing Roof System and Retrofitted Green Roof System in Istanbul, Turkey

    Directory of Open Access Journals (Sweden)

    Nil TÜRKERİ

    2011-01-01

    Full Text Available Urban heat islands, temperature increase due to climate change and energy consumption due to high summer cooling load are significant issues in Turkey. International studies indicate that the green roof system serves as an energy efficient building technology. However, the thermal performance of green roofs when exposed to local climate conditions is still unknown in Turkey. A research project is being conducted at Istanbul Technical University, in which part of a low-slope existing roof system was retrofitted as an extensive green roof system and the thermal performances of both the existing roof and green roof were monitored in order to make a comparative assessment. Both the green roof and the existing roof were instrumented to measure the temperature profile within the roof systems and the solar reflectance of the roof surfaces. Local meteorological variables were also measured. Results obtained from the field monitoring revealed the following data. Reflected solar radiation from the green roof surface was slightly higher than from the existing roof surface. This was likely to be due to the fact that the plants had not yet covered the entire soil surface area of the green roof. Plants reduced the amount of heat absorbed by the growing medium during daytime through shading and reduced the surface temperature of the green roof. Ceiling temperatures of rooms under the existing roof and green roof indicated that heat transfer to the room beneath the green roof was reduced as well. The green roof reduced the heat gain due to the thermal mass of the soil. This created a buffer against daily fluctuations in temperature and minimized temperature extremes.

  15. Water quality and quantity investigation of green roofs in a dry climate.

    Science.gov (United States)

    Beecham, S; Razzaghmanesh, M

    2015-03-01

    Low-energy pollutant removal strategies are now being sought for water sensitive urban design. This paper describes investigations into the water quality and quantity of sixteen, low-maintenance and unfertilized intensive and extensive green roof beds. The factors of Slope (1° and 25°), Depth (100 mm and 300 mm), Growing media (type A, type B and type C) and Species (P1, P2 and P3) were randomized according to a split-split plot design. This consisted of twelve vegetated green roof beds and four non-vegetated beds as controls. Stormwater runoff was collected from drainage points that were installed in each area. Samples of run-off were collected for five rainfall events and analysed for water retention capacity and the water quality parameters of NO₂, NO₃, NH₄, PO₄, pH, EC, TDS, Turbidity, Na, Ca, Mg and K. The results indicated significant differences in terms of stormwater water quality and quantity between the outflows of vegetated and non-vegetated systems. The water retention was between 51% and 96% and this range was attributed to the green roof configurations in the experiment. Comparing the quality of rainfall as inflow, and the quality of runoff from the systems showed that green roofs generally acted as a source of pollutants in this study. In the vegetated beds, the intensive green roofs performed better than the extensive beds with regard to outflow quality while in the non-vegetated beds, the extensive beds performed better than intensive systems. This highlights the importance of vegetation in improving water retention capacity as well as the role of vegetation in enhancing pollutant removal in green roof systems. In addition growing media with less organic matter had better water quality performance. Comparison of these results with national and international standards for water reuse confirmed that the green roof outflow was suitable for non-potable uses such as landscape irrigation and toilet flushing. Copyright © 2014 Elsevier Ltd. All

  16. The Development of a Roof Integrated Solar Hot Water System

    Energy Technology Data Exchange (ETDEWEB)

    Menicucci, David F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Energy Infrastructure and DER Dept.; Moss, Timothy A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Solar Technologies Dept.; Palomino, G. Ernest [Salt River Project (SRP), Tempe, AZ (United States)

    2006-09-01

    The Salt River Project (SRP), in conjunction with Sandia National Laboratories (SNL) and Energy Laboratories, Inc. (ELI), collaborated to develop, test, and evaluate an advanced solar water-heating product for new homes. SRP and SNL collaborated under a Department of Energy Cooperative Research and Development Agreement (CRADA), with ELI as SRP's industry partner. The project has resulted in the design and development of the Roof Integrated Thermal Siphon (RITH) system, an innovative product that features complete roof integration, a storage tank in the back of the collector and below the roofline, easy installation by homebuilders, and a low installed cost. SRP's market research guided the design, and the laboratory tests conducted at SNL provided information used to refine the design of field test units and indicated that the RITH concept is viable. ELI provided design and construction expertise and is currently configured to manufacture the units. This final report for the project provides all of the pertinent and available materials connected to the project including market research studies, the design features and development of the system, and the testing and evaluation conducted at SNL and at a model home test site in Phoenix, Arizona.

  17. Analysis of the Umbrella Roof for lifting

    International Nuclear Information System (INIS)

    Shaaban, A.

    1983-01-01

    In addition to supporting the dead loads and the operational loads, the Umbrella Roof (UR) has two major functions to which it was designed. First is to allow access for repair and removal of any of the TF coils, the upper PF coils and the Vacuum Vessel sections; and second, is to reproduce the exact positioning of the upper PF coils every time the UR is placed over the Tokamac. To provide these functions, the UR is designed to be lifted as one integrated structure to which the upper PF coils are attached. In order to ensure precise positioning of the UR, a redundant system of 13 guide pins were provided on the bottom of the radial beams, and four shear lugs were provided atop the central column. Mating reciprocals with very close tolerance for the guide pins were provided in the tops of the 13 peripheral columns. To meet close tolerances and to accommodate such high redundancy in match points, accurate analysis was necessary by which the center of gravity of the UR can be located and the deflection of all match points can be computed. Also stress analysis of the members of the UR was necessary because when the UR is lifted it is denied the midpoint support over the center column; and also the beams of the UR are not interconnected by moment-capable joints, thus if provisions are not made to support every radial beam, those which are not supported would yield and collapse. In this paper, the lifting schemes proposed for the UR are discussed and the results of the analysis performed for the elected scheme are presented. Also presented is a unique application of the NASTRAN code by which the center of gravity of the UR was located by allowing a refined model of the UR to swing until it came to rest under an arbitrary lift point

  18. Some metals in aboveground biomass of Scots pine in Lithuania

    DEFF Research Database (Denmark)

    Varnagiryte-Kabašinskiene, Iveta; Armolaitis, Kestutis; Stupak, Inge

    2014-01-01

    with stemwood and living branches. However, metal export with aboveground biomass represented relatively small proportion of metals in mineral sandy soil. The annual inputs of Fe and Zn with atmospheric deposition were over 10 times higher than the mean annual removals with total aboveground biomass....... The content of metals in forest biomass fuel ash was relatively small to compare with their total removals. The findings of this study have an important implications for future practice, i.e. the recommended maximum forest biomass fuel ash dose for the compensating fertilising could be increased with respect...... to balanced output - input in Lithuania....

  19. Interactions between aboveground herbivores and the mycorrhizal mutualists of plants.

    Science.gov (United States)

    Gehring, C A; Whitham, T G

    1994-07-01

    Plant growth, reproduction and survival can be affected both by mycorrhizal fungi and aboveground herbivores, but few studies have examined the interactive effects of these factors on plants. Most of the available data suggest that severe herbivory reduces root colonization by vesicular-arbuscular and ectomycorrhizal fungi. However, the reverse interaction has also been documented - mycorrhizal fungi deter herbivores and interact with fungal endophytes to influence herbivory. Although consistent patterns and mechanistic explanations are yet to emerge, it is likely that aboveground herbivore-mycorrhiza interactions have important implications for plant populations and communities. Copyright © 1994. Published by Elsevier Ltd.

  20. Metal and nutrient dynamics on an aged intensive green roof

    International Nuclear Information System (INIS)

    Speak, A.F.; Rothwell, J.J.; Lindley, S.J.; Smith, C.L.

    2014-01-01

    Runoff and rainfall quality was compared between an aged intensive green roof and an adjacent conventional roof surface. Nutrient concentrations in the runoff were generally below Environmental Quality Standard (EQS) values and the green roof exhibited NO 3 − retention. Cu, Pb and Zn concentrations were in excess of EQS values for the protection of surface water. Green roof runoff was also significantly higher in Fe and Pb than on the bare roof and in rainfall. Input–output fluxes revealed the green roof to be a potential source of Pb. High concentrations of Pb within the green roof soil and bare roof dusts provide a potential source of Pb in runoff. The origin of the Pb is likely from historic urban atmospheric deposition. Aged green roofs may therefore act as a source of legacy metal pollution. This needs to be considered when constructing green roofs with the aim of improving pollution remediation. -- Highlights: • Runoff from an aged intensive green roof was characterised. • Nutrient levels were not problematic for runoff quality. • High concentrations of Cu, Pb and Zn were found in the runoff. • Soil contamination was a likely source of metals in roof runoff. • Historic Pb atmospheric deposition may be the source of contamination. -- Aged green roofs may act as a store of legacy lead pollution

  1. Weathering of Roofing Materials-An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Berdahl, Paul; Akbari, Hashem; Levinson, Ronnen; Miller, William A.

    2006-03-30

    An overview of several aspects of the weathering of roofing materials is presented. Degradation of materials initiated by ultraviolet radiation is discussed for plastics used in roofing, as well as wood and asphalt. Elevated temperatures accelerate many deleterious chemical reactions and hasten diffusion of material components. Effects of moisture include decay of wood, acceleration of corrosion of metals, staining of clay, and freeze-thaw damage. Soiling of roofing materials causes objectionable stains and reduces the solar reflectance of reflective materials. (Soiling of non-reflective materials can also increase solar reflectance.) Soiling can be attributed to biological growth (e.g., cyanobacteria, fungi, algae), deposits of organic and mineral particles, and to the accumulation of flyash, hydrocarbons and soot from combustion.

  2. Impact of Sustainable Cool Roof Technology on Building Energy Consumption

    Science.gov (United States)

    Vuppuluri, Prem Kiran

    Highly reflective roofing systems have been analyzed over several decades to evaluate their ability to meet sustainability goals, including reducing building energy consumption and mitigating the urban heat island. Studies have isolated and evaluated the effects of climate, surface reflectivity, and roof insulation on energy savings, thermal load mitigation and also ameliorating the urban heat island. Other sustainable roofing systems, like green-roofs and solar panels have been similarly evaluated. The motivation for the present study is twofold: the first goal is to present a method for simultaneous evaluation and inter-comparison of multiple roofing systems, and the second goal is to quantitatively evaluate the realized heating and cooling energy savings associated with a white roof system compared to the reduction in roof-top heat flux. To address the first research goal a field experiment was conducted at the International Harvester Building located in Portland, OR. Thermal data was collected for a white roof, vegetated roof, and a solar panel shaded vegetated roof, and the heat flux through these roofing systems was compared against a control patch of conventional dark roof membrane. The second research goal was accomplished using a building energy simulation program to determine the impact of roof area and roof insulation on the savings from a white roof, in both Portland and Phoenix. The ratio of cooling energy savings to roof heat flux reduction from replacing a dark roof with a white roof was 1:4 for the month of July, and 1:5 annually in Portland. The COP of the associated chillers ranges from 2.8-4.2, indicating that the ratio of cooling energy savings to heat flux reduction is not accounted for solely by the COP of the chillers. The results of the building simulation indicate that based on energy savings alone, white roofs are not an optimal choice for Portland. The benefits associated with cooling energy savings relative to a black roof are offset by

  3. Green roof rainfall-runoff modelling: is the comparison between conceptual and physically based approaches relevant?

    Science.gov (United States)

    Versini, Pierre-Antoine; Tchiguirinskaia, Ioulia; Schertzer, Daniel

    2017-04-01

    Green roofs are commonly considered as efficient tools to mitigate urban runoff as they can store precipitation, and consequently provide retention and detention performances. Designed as a compromise between water holding capacity, weight and hydraulic conductivity, their substrate is usually an artificial media differentiating significantly from a traditional soil. In order to assess green roofs hydrological performances, many models have been developed. Classified into two categories (conceptual and physically based), they are usually applied to reproduce the discharge of a particular monitored green roof considered as homogeneous. Although the resulted simulations could be satisfactory, the question of robustness and consistency of the calibrated parameters is often not addressed. Here, a modeling framework has been developed to assess the efficiency and the robustness of both modelling approaches (conceptual and physically based) in reproducing green roof hydrological behaviour. SWMM and VS2DT models have been used for this purpose. This work also benefits from an experimental setup where several green roofs differentiated by their substrate thickness and vegetation cover are monitored. Based on the data collected for several rainfall events, it has been studied how the calibrated parameters are effectively linked to their physical properties and how they can vary from one green roof configuration to another. Although both models reproduce correctly the observed discharges in most of the cases, their calibrated parameters exhibit a high inconsistency. For a same green roof configuration, these parameters can vary significantly from one rainfall event to another, even if they are supposed to be linked to the green roof characteristics (roughness, residual moisture content for instance). They can also be different from one green roof configuration to another although the implemented substrate is the same. Finally, it appears very difficult to find any

  4. Green roofs as a means of pollution abatement

    International Nuclear Information System (INIS)

    Rowe, D. Bradley

    2011-01-01

    Green roofs involve growing vegetation on rooftops and are one tool that can help mitigate the negative effects of pollution. This review encompasses published research to date on how green roofs can help mitigate pollution, how green roof materials influence the magnitude of these benefits, and suggests future research directions. The discussion concentrates on how green roofs influence air pollution, carbon dioxide emissions, carbon sequestration, longevity of roofing membranes that result in fewer roofing materials in landfills, water quality of stormwater runoff, and noise pollution. Suggestions for future directions for research include plant selection, development of improved growing substrates, urban rooftop agriculture, water quality of runoff, supplemental irrigation, the use of grey water, air pollution, carbon sequestration, effects on human health, combining green roofs with complementary related technologies, and economics and policy issues. - Green roofs can help mitigate air pollution, carbon dioxide emissions, sequester carbon, conserve energy, reduce the urban heat island, and improve water quality.

  5. Aboveground Whitefly Infestation-Mediated Reshaping of the Root Microbiota.

    Science.gov (United States)

    Kong, Hyun G; Kim, Byung K; Song, Geun C; Lee, Soohyun; Ryu, Choong-Min

    2016-01-01

    Plants respond to various types of herbivore and pathogen attack using well-developed defensive machinery designed for self-protection. Infestation from phloem-sucking insects such as whitefly and aphid on plant leaves was previously shown to influence both the saprophytic and pathogenic bacterial community in the plant rhizosphere. However, the modulation of the root microbial community by plants following insect infestation has been largely unexplored. Only limited studies of culture-dependent bacterial diversity caused by whitefly and aphid have been conducted. In this study, to obtain a complete picture of the belowground microbiome community, we performed high-speed and high-throughput next-generation sequencing. We sampled the rhizosphere soils of pepper seedlings at 0, 1, and 2 weeks after whitefly infestation versus the water control. We amplified a partial 16S ribosomal RNA gene (V1-V3 region) by polymerase chain reaction with specific primers. Our analysis revealed that whitefly infestation reshaped the overall microbiota structure compared to that of the control rhizosphere, even after 1 week of infestation. Examination of the relative abundance distributions of microbes demonstrated that whitefly infestation shifted the proteobacterial groups at week 2. Intriguingly, the population of Pseudomonadales of the class Gammaproteobacteria significantly increased after 2 weeks of whitefly infestation, and the fluorescent Pseudomonas spp. recruited to the rhizosphere were confirmed to exhibit insect-killing capacity. Additionally, three taxa, including Caulobacteraceae, Enterobacteriaceae, and Flavobacteriaceae, and three genera, including Achromobacter, Janthinobacterium, and Stenotrophomonas, were the most abundant bacterial groups in the whitefly infested plant rhizosphere. Our results indicate that whitefly infestation leads to the recruitment of specific groups of rhizosphere bacteria by the plant, which confer beneficial traits to the host plant. This

  6. Aboveground Whitefly Infestation-mediated Reshaping of the Root Microbiota

    Directory of Open Access Journals (Sweden)

    Hyun Gi Kong

    2016-09-01

    Full Text Available Plants respond to various types of herbivore and pathogen attack using well-developed defensive machinery designed for self-protection. The phloem-sucking insect infestation such as whitefly and aphid on plant leaves were previously shown to influence both the saprophytic and pathogenic bacterial community in the plant rhizosphere. However, the modulation of the root microbial community by plants following insect infestation has been largely unexplored. Only limited studies of culture-dependent bacterial diversity caused by whitefly and aphid have been conducted. In this study, to obtain a complete picture of the belowground microbiome community, we performed high-speed and high-throughput next-generation sequencing. We sampled the rhizosphere soils of pepper seedlings at 0, 1, and 2 weeks after whitefly infestation versus the water control. We amplified a partial 16S ribosomal RNA gene (V1–V3 region by polymerase chain reaction with specific primers. Our analysis revealed that whitefly infestation reshaped the overall microbiota structure compared to that of the control rhizosphere, even after 1 week of infestation. Examination of the relative abundance distributions of microbes demonstrated that whitefly infestation shifted the proteobacterial groups at week 2. Intriguingly, the population of Pseudomonadales of the class Gammaproteobacteria significantly increased after 2 weeks of whitefly infestation and confirmed the recruitment of fluorescent Pseudomonas spp. exhibiting the insect-killing capacity. Additionally, three taxa, including Caulobacteraceae, Enterobacteriaceae, and Flavobacteriaceae, and three genera, including Achromobacter, Janthinobacterium, and Stenotrophomonas, were the most abundant bacterial groups in the whitefly-infested plant rhizosphere. Our results indicate that whitefly infestation leads plant recruiting specific group of rhizosphere bacteria conferring beneficial traits for host plant. This study provides a new

  7. Sustainable urban energy: Development of a mesoscale assessment model for solar reflective roof technologies

    International Nuclear Information System (INIS)

    Jo, J.H.; Carlson, J.; Golden, J.S.; Bryan, H.

    2010-01-01

    Buildings and other engineered structures that form cities are responsible for a significant portion of the global and local impacts of climate change. Consequently, the incorporation of building design strategies and materials such as the use of reflective roof materials, or 'cool' roofs, are being widely investigated. However, although their benefits for individual buildings have been studied, as yet there is little understanding of the potential benefits of urban scale implementation of such systems. Here we report the development of a new methodology for assessing the potential capacity and benefits of installing reflective roofs in an urbanized area. The new methodology combines remote sensing image data with a building energy computer simulation to quantify the current rooftop reflectivity and predict the potential benefits of albedo improvement. In addition to the direct electricity savings, cool roof systems reduce peak electrical demand in the month of August when the peak demand is at its highest in the case study area. Environmental benefits associated with lowering greenhouse-gas emissions are also substantial. The new methodology allows the calculation of payback periods to assist planners to evaluate the potential economic benefits of the widespread installation of cool roof systems. - Research highlights: →Integrated remote sensing technique into building energy simulation quantifies rooftop reflectivity and predicts the potential benefits of albedo improvement. →70% buildings can improve rooftop reflectivity. →Cool roof application can reduce the study area's electrical demand by 4.3%. →Payback period will be 7-11 years depending on low and high-end cool roof cost assumptions.

  8. Temporal variations in the potential hydrological performance of extensive green roof systems

    Science.gov (United States)

    De-Ville, Simon; Menon, Manoj; Stovin, Virginia

    2018-03-01

    Existing literature provides contradictory information about variation in potential green roof hydrological performance over time. This study has evaluated a long-term hydrological monitoring record from a series of extensive green roof test beds to identify long-term evolutions and sub-annual (seasonal) variations in potential hydrological performance. Monitoring of nine differently-configured extensive green roof test beds took place over a period of 6 years in Sheffield, UK. Long-term evolutions and sub-annual trends in maximum potential retention performance were identified through physical monitoring of substrate field capacity over time. An independent evaluation of temporal variations in detention performance was undertaken through the fitting of reservoir-routing model parameters. Aggregation of the resulting retention and detention variations permitted the prediction of extensive green roof hydrological performance in response to a 1-in-30-year 1-h summer design storm for Sheffield, UK, which facilitated the comparison of multi and sub-annual hydrological performance variations. Sub-annual (seasonal) variation was found to be significantly greater than long-term evolution. Potential retention performance increased by up to 12% after 5-years, whilst the maximum sub-annual variation in potential retention was 27%. For vegetated roof configurations, a 4% long-term improvement was observed for detention performance, compared to a maximum 63% sub-annual variation. Consistent long-term reductions in detention performance were observed in unvegetated roof configurations, with a non-standard expanded-clay substrate experiencing a 45% reduction in peak attenuation over 5-years. Conventional roof configurations exhibit stable long-term hydrological performance, but are nonetheless subject to sub-annual variation.

  9. The Perception of Malaysian Architects towards the Implementation of Green Roofs: A Review of Practices, Methodologies and Future Research

    Directory of Open Access Journals (Sweden)

    Zahir M.H. Md.

    2014-01-01

    Full Text Available The implementation of green roofs or vegetated roof as a sustainable tool to mitigate the Urban Heat Island effect is relatively new in Malaysia. Although it has not been tested on an urban scale, many research findings have indicated that green roofs can contribute towards enhancing the environmental and aesthetical quality of the built environment. It was hypothesized that the low application of green roofs in the Malaysian construction industry is due to the lack of awareness, understanding and experience in its benefits especially among building practitioners. As a result, this research was initiated to determine the perception and understanding of Malaysian architects in green roofs implementation issues, as well as to identify their level of acceptance and readiness. This paper reviews practices and different research approaches in understanding the factors that influence architect’s perception towards the implementation of green roofs in the Malaysian construction industry. Architects were chosen as the only respondents due to their intensive involvement in the conceptualisation, planning, design and construction stage of a built environment project. Extensive literature review was conducted to explore past experiences in green roof implementation and to develop the theoretical framework for this research.

  10. Large grazers modify effects of aboveground-belowground interactions on small-scale plant community composition

    NARCIS (Netherlands)

    Veen, G. F. (Ciska); Geuverink, Elzemiek; Olff, Han; Schmid, Bernhard

    Aboveground and belowground organisms influence plant community composition by local interactions, and their scale of impact may vary from millimeters belowground to kilometers aboveground. However, it still poorly understood how large grazers that select their forage on large spatial scales

  11. Aboveground Biomass and Litterfall Dynamics in Secondary Forest ...

    African Journals Online (AJOL)

    The differences in aboveground biomass, litterfall patterns and the seasonality of litterfall in three secondary forest fields aged 1, 5 and 10 years of age regenerating from degraded abandoned rubber plantation and a mature forest were studied in southern Nigeria. This is with a view to understanding the possibility of ...

  12. Estimates of forest canopy height and aboveground biomass using ICESat.

    Science.gov (United States)

    Michael A. Lefsky; David J. Harding; Michael Keller; Warren B. Cohen; Claudia C. Carabajal; Fernando Del Bom; Maria O. Hunter; Raimundo Jr. de Oliveira

    2005-01-01

    Exchange of carbon between forests and the atmosphere is a vital component of the global carbon cycle. Satellite laser altimetry has a unique capability for estimating forest canopy height, which has a direct and increasingly well understood relationship to aboveground carbon storage. While the Geoscience Laser Altimeter System (GLAS) onboard the Ice, Cloud and land...

  13. Inventory of Tank Farm equipment stored or abandoned aboveground

    International Nuclear Information System (INIS)

    Hines, S.C.; Lakes, M.E.

    1994-01-01

    This document provides an inventory of Tank Farm equipment stored or abandoned aboveground and potentially subject to regulation. This inventory was conducted in part to ensure that Westinghouse Hanford Company (WHC) does not violate dangerous waste laws concerning storage of potentially contaminated equipment/debris that has been in contact with dangerous waste. The report identifies areas inventoried and provides photographs of equipment

  14. Steering soil microbiomes to suppress aboveground insect pests

    NARCIS (Netherlands)

    Pineda, Ana; Kaplan, Ian; Bezemer, T. Martijn

    2017-01-01

    Soil-borne microbes affect aboveground herbivorous insects through a cascade of molecular and chemical changes in the plant, but knowledge of these microbe?plant?insect interactions is mostly limited to one or a few microbial strains. Yet, the soil microbial community comprises thousands of unique

  15. WIPP supplementary roof support system Room 1, Panel 1: Geotechnical field data analysis report

    International Nuclear Information System (INIS)

    1993-03-01

    The design of the Room 1, Panel 1, supplementary roof support system was finalized in September 1991, and the system successfully installed in the test bin area between the bulkheads by December 1991. Simultaneously with the support system installation, existing monitoring system was upgraded to meet the needs of the installed roof support. This included extensometers, closure stations, rockbolt load cells as well as survey measurements of roof sag and floor lift. A Project Control Group (PCG) was established in order to monitor room and support system performance. Weekly meetings of the PCG were held to review all monitored data against criteria set in the initial design, and to modify these where necessary. Records of these meetings have been kept, with copies of all data summaries and action notes. These data records are maintained in the Engineering data files. After more than ten months of monitoring and reviewing experience, several modifications have been made both to the way data has been reported as well as to the load adjustment criteria. The support system has performed as expected in the design, with no signs of instability developing considering the rates of roof deformation, the rock bolt loads and the observed fracture behavior in the roof. This is particularly true of the horizon in which the rockbolt anchors are located, the most critical part of the design. The distribution of load build-up, throughout the 286 rockbolt load cells installed, in the Room 1 has been found satisfactory, and the load increases as evaluated by the PCG on a weekly basis have been within the acceptable range. The minimum life of the installed support system is estimated at 15 years based on the highest roof expansion rate experienced to date. This report provides analysis of geotechnical field data collected up to December 1992

  16. Bamboo Fibre Reinforced Cement Used as a Roofing Sheet | Alade ...

    African Journals Online (AJOL)

    Bamboo fibre roofing sheet was able to withstand an average load of 51Kg, which is above the minimum required strength of 50kg. Comparatively, Asbestos roofing sheets and coconut fibre roofing sheets of similar dimensions had failure loads of 104.65Kg and 79Kg respectively. When immersed in water, bamboo fibre ...

  17. Green roofs : a resource manual for municipal policy makers

    Energy Technology Data Exchange (ETDEWEB)

    Lawlor, G.; Currie, B.A.; Doshi, H.; Wieditz, I. [Canada Mortgage and Housing Corp., Ottawa, ON (Canada)

    2006-05-15

    As knowledge of the environmental benefits of green roofs and technology improves, green roofs are quickly gaining acceptance in North America. European jurisdictions have been using green roof technology for stormwater management, to reduce energy use in buildings and to increase amenity space. By reviewing the reasons that municipalities throughout the world have set green roof policies and programs, policy makers can more easily determine which policies suit their needs. This manual provided an overview of international and Canadian green roof policies and programs. It presented information on 12 jurisdictions that demonstrated leadership in green roof policy development. The manual also presented information on an additional 13 jurisdictions with less-developed green roof policies. Activities that were discussed for each of these jurisdictions included: description of jurisdiction; key motivators; green roof policy; process to establish policy; effectiveness; lessons learned; future predictions; and applicability to Canada of international jurisdictions. The manual also provided general information on green roofs such as a definition of green roofs and green roof terminology. Key motivators for green roofs include stormwater runoff control; reduction in urban heat-island effect; reduction in building energy consumption; and air pollution control. refs., tabs., figs.

  18. Load-Bearing Capacity of Roof Trusses

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Damkilde, Lars; Munch-Andersen, J.

    2004-01-01

    systems such as roof trusses are established and statistical characteristics of the load bearing capacity are determined. The results show that there is a significant increase in the characteristic (nominal) value and a reduction in the coefficient of variation (COV) for typical loads such as permanent...

  19. The 3rd power unit roofing decontamination

    International Nuclear Information System (INIS)

    Samojlenko, Yu.N.; Golubev, V.V.

    1989-01-01

    The most features of the 3rd power unit (PU) roofing decontamination are described: 1) the most active materials were thrown into the 4th PU ruins before the Ukrytie construction completion; 2) the decontamination was fulfilled using remote-controlled mechanisms and manual devices (the main part). 6 figs.; 1 tab

  20. Rating system for coal mine roofs

    CSIR Research Space (South Africa)

    Canbulat, I

    2002-09-01

    Full Text Available It is standard practice in the majority of rock engineering applications to use a rock mass classification method to evaluate the condition of rock, i.e. to quantify, in an objective manner, the characteristics of good or bad roof. These rockmass...

  1. Monitoring roof beam lateral displacement at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Terrill, L.J.; Lewis, R.E.

    1996-01-01

    Lateral displacement in the immediate roof beam at the Waste Isolation Pilot Plant (WIPP) is a significant factor in assessment of excavation performance for the design of ground control systems. Information on roof beam lateral displacement, expansion, fracture formation, as well as excavation convergence, is gathered using a variety of manually and remotely read instruments. Visual observations are also used when possible. This paper describes the methods used to measure lateral displacement, or offset, at the WIPP. Offset magnitudes are determined by the degree of occlusion in drillholes that intersect the offset plane. The Borehole Lateral Displacement Sensor (BLDS) was developed for installation at WIPP to monitor offset at a high degree of accuracy at a short reading frequency. Offset measurements have historically been obtained by visual estimation of borehole conclusion. Use of the BLDS will enable relationships between time dependent roof beam lateral displacement and expansion to be established in much shorter periods than is possible using visual observations. The instrument will also allow remote monitoring of roof beam displacement in areas where visual estimations are not possible. Continued monitoring of roof beam displacement, convergence, and expansion, is integral to timely and pertinent assessments of WIPP excavation performance

  2. The growth and survival of plants in urban green roofs in a dry climate.

    Science.gov (United States)

    Razzaghmanesh, M; Beecham, S; Kazemi, F

    2014-04-01

    Green roofs as one of the components of water-sensitive urban design have become widely used in recent years. This paper describes performance monitoring of four prototype-scale experimental green roofs in a northern suburb of Adelaide, South Australia, undertaken over a 1-year period. Four species of indigenous Australian ground cover and grass species comprising Carpobrotus rossii, Lomandra longifolia 'Tanika,' Dianella caerula 'Breeze' and Myoporum parvifolium were planted in extensive and intensive green roof configurations using two different growing media. The first medium consisted of crushed brick, scoria, coir fibre and composted organics while the second comprised scoria, composted pine bark and hydro-cell flakes. Plant growth indices including vertical and horizontal growth rate, leaf succulence, shoot and root biomasses, water use efficiency and irrigation regimes were studied during a 12-month period. The results showed that the succulent species, C. rossii, can best tolerate the hot, dry summer conditions of South Australia, and this species showed a 100% survival rate and had the maximum horizontal growth rate, leaf succulence, shoot biomass and water use efficiency. All of the plants in the intensive green roofs with the crushed brick mix media survived during the term of this study. It was shown that stormwater can be used as a source of irrigation water for green roofs during 8 months of the year in Adelaide. However, supplementary irrigation is required for some of the plants over a full annual cycle. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Green Roofs and Green Walls for Biodiversity Conservation: A Contribution to Urban Connectivity?

    Directory of Open Access Journals (Sweden)

    Flavie Mayrand

    2018-03-01

    Full Text Available Green roofs and walls have recently emerged as conservation tools, and they offer promising additional opportunities to enhance biodiversity in cities. However, their ecological conditions remain poorly considered when planning wildlife corridors. To discuss the role of vegetated buildings in landscape connectivity, we reviewed the ecological and technical specificities of green walls and green roofs in light of the key factors concerning urban wildlife (patch size, quality, abundance, and isolation. Green roofs and walls show limited patch sizes, distinct habitat quality at the building scale, and limited redundancy of patch quality within the landscape. We also highlight that the abundance of roof and wall patches is often low. Future research is needed to establish if walls can be vertical corridors for wildlife, thereby reducing the isolation of green roofs. We argue that creating 3D ecological connectivity within the city requires substantial modifications of the design and maintenance of existing green building systems. We suggest that research is needed to integrate the biotic and abiotic characteristics of green buildings to make them more closely resemble those of open green spaces.

  4. Monitoring roof beam lateral displacement at the waste isolation pilot plant

    International Nuclear Information System (INIS)

    Terrill, L.J.; Lewis, R.E.

    1996-01-01

    Lateral displacement in the immediate roof beam at the Waste Isolation Pilot Plant (WIPP) is a significant factor in assessment of excavation performance for the design of ground control systems. Information on roof beam lateral displacement, expansion, fracture formation, as well as excavation convergence, is gathered using a variety of manually and remotely read instruments. Visual observations are also used when possible. This paper describes the methods used to measure lateral displacement, or offset, at the WIPP. Offset magnitudes are determined by the degree of occlusion in drillholes that intersect the offset plane. The Borehole Lateral Displacement Sensor (BLDS) was developed for installation at WIPP to monitor offset at a high degree of accuracy at a short reading frequency. Offset measurements have historically been obtained by visual estimation of borehole occlusion. Use of the BLDS will enable relationships between time dependent roof beam lateral displacement and expansion to be established in much shorter periods than is possible using visual observations. The instrument will also allow remote monitoring of roof beam displacement in areas where visual estimations are not possible. Continued monitoring of roof beam displacement, convergence, and expansion, is integral to timely and pertinent assessments of WIPP excavation performance

  5. Glazed ceramic roof tiles: influence of surface features in the solar reflectance index

    International Nuclear Information System (INIS)

    Bortoli, Leitcia Silva de; Stapait, Camila Cristina; Marinoski, Deivis Luis; Fredel, Marcio Celso; Schabbach, Luciana M.

    2016-01-01

    In this study the influence of surface features of ceramic roof tiles in the solar reflectance index were evaluated. Two glazed ceramic roof tiles (type stoneware) with the same color (ivory) but with different appearance (matte and brilliant) were the focus of the analysis. The Solar Reflectance Index (SRI) of the roofs tiles were determined by the solar reflectance values (UV-VIS-NIR) and emittance, measured in laboratory. The samples showed SRI> 39 in accordance with LEED certification criteria (Leadership in Energy and Environmental Design), contributing to minimizing the Heat Island Effects. Although the matte roof tile shows a slightly higher SRI value (82) than the brilliant one (78), the results for the variables that composes the SRI value (reflectance and emittance) were very similar. Analysis of XRD, SEM and EDS performed on the surfaces of the two roofs indicated for the matte glaze the presence of microcrystals (with barium and zinc) that can contribute to the slightly highest value of SRI. The roughness (optical interferometer white light) and the brightness (brightness meter) of the samples were also measured. (author)

  6. Performance evaluation on cool roofs for green remodeling

    Science.gov (United States)

    Yun, Yosun; Cho, Dongwoo; Cho, Kyungjoo

    2018-06-01

    Cool roofs refer that maximize heat emission, and minimize the absorption of solar radiation energy, by applying high solar reflectance paints, or materials to roofs or rooftops. The application of cool roofs to existing buildings does not need to take structural issues into consideration, as rooftop greening, is an alternative that can be applied to existing buildings easily. This study installed a cool roofs on existing buildings, and evaluated the performances, using the results to propose certification standards for green remodeling, considering the cool roof-related standards.

  7. The influence of a cubic building on a roof mounted wind turbine

    OpenAIRE

    Micallef, D.; Sant, Tonio; Simao Ferreira, C.

    2016-01-01

    The performance of a wind turbine located above a cubic building is not well understood. This issue is of fundamental importance for the design of small scale wind turbines. One variable which is of particular importance in this respect is the turbine height above roof level. In this work, the power performance of a small wind turbine is assessed as a function of the height above the roof of a generic cubic building. A 3D Computational Fluid Dynamics model of a 10m x 10m x 10m building is use...

  8. The role of above-ground competition and nitrogen vs. phosphorus enrichment in seedling survival of common European plant species of semi-natural grasslands.

    Directory of Open Access Journals (Sweden)

    Tobias Ceulemans

    Full Text Available Anthropogenic activities have severely altered fluxes of nitrogen and phosphorus in ecosystems worldwide. In grasslands, subsequent negative effects are commonly attributed to competitive exclusion of plant species following increased above-ground biomass production. However, some studies have shown that this does not fully account for nutrient enrichment effects, questioning whether lowering competition by reducing grassland productivity through mowing or herbivory can mitigate the environmental impact of nutrient pollution. Furthermore, few studies so far discriminate between nitrogen and phosphorus pollution. We performed a full factorial experiment in greenhouse mesocosms combining nitrogen and phosphorus addition with two clipping regimes designed to relax above-ground competition. Next, we studied the survival and growth of seedlings of eight common European grassland species and found that five out of eight species showed higher survival under the clipping regime with the lowest above-ground competition. Phosphorus addition negatively affected seven plant species and nitrogen addition negatively affected four plant species. Importantly, the negative effects of nutrient addition and higher above-ground competition were independent of each other for all but one species. Our results suggest that at any given level of soil nutrients, relaxation of above-ground competition allows for higher seedling survival in grasslands. At the same time, even at low levels of above-ground competition, nutrient enrichment negatively affects survival as compared to nutrient-poor conditions. Therefore, although maintaining low above-ground competition appears essential for species' recruitment, for instance through mowing or herbivory, these management efforts are likely to be insufficient and we conclude that environmental policies aimed to reduce both excess nitrogen and particularly phosphorus inputs are also necessary.

  9. Water quality function of an extensive vegetated roof.

    Science.gov (United States)

    Todorov, Dimitar; Driscoll, Charles T; Todorova, Svetoslava; Montesdeoca, Mario

    2018-06-01

    In this paper we present the results of a four-year study of water quality in runoff from an extensive, sedum covered, vegetated roof on an urban commercial building. Monitoring commenced seven months after the roof was constructed, with the first growing season. Stormwater drainage quality function of the vegetated roof was compared to a conventional (impermeable, high-albedo) membrane roof in addition to paired measurements of wet and bulk depositions at the study site. We present concentrations and fluxes of nutrients and major solutes. We discuss seasonal and year-to-year variation in water quality of drainage from the vegetated roof and how it compares with atmospheric deposition and drainage from the impermeable roof. Drainage waters from the vegetated roof exhibited a high concentration of nutrients compared to atmospheric deposition, particularly during the warm temperature growing season. However, nutrient losses were generally low because of the strong retention of water by the vegetated roof. There was marked variation in the retention of nutrients by season due to variations in concentrations in drainage from the vegetated roof. The vegetated roof was a sink of nitrogen, total phosphorus and chloride, and a source of phosphate and dissolved inorganic and organic carbon. Chloride exhibited elevated inputs and leaching during the winter. The drainage from the vegetated and impermeable roofs met the United States Environmental Protection Agency freshwater standards for all parameters, except for total phosphorus. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Integration of thermal insulation coating and moving-air-cavity in a cool roof system for attic temperature reduction

    International Nuclear Information System (INIS)

    Yew, M.C.; Ramli Sulong, N.H.; Chong, W.T.; Poh, S.C.; Ang, B.C.; Tan, K.H.

    2013-01-01

    Highlights: • A novel integrated cool roof system for attic temperature reduction is introduced. • 13 °C temperature reduction achieved due to its efficient heat transfer mechanism. • Aluminium tube cavity of the roof is able to reduce the attic temperature. • This positive result is due to its efficient heat reflection and hot air rejection. • Thermal insulation coating incorporates the usage of eggshell waste as bio-filler. - Abstract: Cool roof systems play a significant role in enhancing the comfort level of occupants by reducing the attic temperature of the building. Heat transmission through the roof can be reduced by applying thermal insulation coating (TIC) on the roof and/or installing insulation under the roof of the attic. This paper focuses on a TIC integrated with a series of aluminium tubes that are installed on the underside of the metal roof. In this study, the recycled aluminium cans were arranged into tubes that act as a moving-air-cavity (MAC). The TIC was formulated using titanium dioxide pigment with chicken eggshell (CES) waste as bio-filler bound together by a polyurethane resin binder. The thermal conductivity of the thermal insulation paint was measured using KD2 Pro Thermal Properties Analyzer. Four types of cool roof systems were designed and the performances were evaluated. The experimental works were carried out indoors by using halogen light bulbs followed by comparison of the roof and attic temperatures. The temperature of the surrounding air during testing was approximately 27.5 °C. The cool roof that incorporated both TIC and MAC with opened attic inlet showed a significant improvement with a reduction of up to 13 °C (from 42.4 °C to 29.6 °C) in the attic temperature compared to the conventional roof system. The significant difference in the results is due to the low thermal conductivity of the thermal insulation paint (0.107 W/mK) as well as the usage of aluminium tubes in the roof cavity that was able to transfer

  11. Measured efficiency of a luminescent solar concentrator PV module called Leaf Roof

    NARCIS (Netherlands)

    Reinders, Angèle H.M.E; Debije, Michael G.; Rosemann, Alexander

    2017-01-01

    A functional prototype of a luminescent solar concentrator photovoltaic (LSC PV) module, called Leaf Roof, aims at demonstrating the design features of LSC PV technologies such as coloring, transparency, and flexibility in physical shape. In this paper, the prototype is presented and the first

  12. Roof loading and response following a HCDA in a pool-type reactor

    International Nuclear Information System (INIS)

    Lancefield, M.J.; Leigh, K.M.; Potter, R.; Staniforth, R.

    1979-01-01

    In a pool-type reactor the loading and response of the roof structure to a HCDA is important to safety analysis and design. The U.K. programme of experimental and theoretical work on this topic is described. Good progress in understanding and evaluating the complex processes has been made and this is illustrated by results from experimental and theoretical work. 5 refs

  13. The Effect of Roof Angles on Indoor Air Temperatures in Terrace Houses in Malaysia

    Directory of Open Access Journals (Sweden)

    A. B. Ramly

    2006-12-01

    Full Text Available The main aim of energy efficiency in building design is to create buildings that utilise minimum amount of energy while meeting the comfort standards as high as or higher than those provided by conventional buildings.To achieve these standards, it is necessary to study the local environment in order to assess its positive and negative features (impact on the building. The results will provide a basic understanding of heat transfer and human thermal comfort requirements. It also provides foundation for which an energy efficient design of buildings can be established. The design of residential buildings has a significant impact on everyday lives of people. It includes the types and forms of buildings that are commonly occupied by people. In Malaysia, the 'terrace house' constitutes the majority of the residential building stock on which this study is based. The study considers the effects of the different roof angles on reducing solar gain and indoor temperatures through eight directions within 24 hours. To analyse and explain that effect, five different angles of roof were chosen for the simulations. In general, all the angles were chosen due 10 their architectural design characteristics. These angles start from 0 degree as a horizontal flat roof to 60 degrees, i.e. increment of every 15 degrees. The research is seen as providing a tool in evaluating the dynamic indoor air temperature and the effect of roof angles. The evaluation is derived from a series of computer simulations using commercially available software called BLAST.

  14. Resilience of roof-top Plant-Microbial Fuel Cells during Dutch winter

    NARCIS (Netherlands)

    Helder, M.; Strik, D.P.B.T.B.; Timmers, R.A.; Reas, S.M.T.; Hamelers, H.V.M.; Buisman, C.J.N.

    2013-01-01

    The Plant-Microbial Fuel Cell (P-MFC) is in theory a technology that could produce sustainable electricity continuously. We operated two designs of the P-MFC under natural roof-top conditions in the Netherlands for 221 days, including winter, to test its resilience. Current and power densities are

  15. The influence of a cubic building on a roof mounted wind turbine

    NARCIS (Netherlands)

    Micallef, D.; Sant, Tonio; Simao Ferreira, C.

    2016-01-01

    The performance of a wind turbine located above a cubic building is not well understood. This issue is of fundamental importance for the design of small scale wind turbines. One variable which is of particular importance in this respect is the turbine height above roof level. In this work, the

  16. Performance of antisolar insulated roof system

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Irshad [Alternative Energy Development Board (AEDB), House No. 1, Main Nazimuddin Road, F-10/4, Islamabad (Pakistan)

    2010-01-15

    Rooms with concrete slab roofs directly exposed to the sun become unbearably hot during summer and very cold during winter. Huge amounts of energy are required to keep them comfortable. Application of thermal insulation on roofs significantly reduces energy required for heating and cooling. The effectiveness of roof insulations may be further enhanced if a layer of antisolar coating is applied on top of the insulation. The antisolar coating reflects most of the incident sunlight and prevents the roof from heating up. This reduces the daily cycles of thermal expansion and contraction which cause cracks in the roof slabs for the rainwater to leak through. The antisolar coating prolongs the useful life of the building structure as well as the life of the insulation that evaporates with heat. The method of application of the antisolar coating has been specially developed to eliminate thermal bridges formed between the edges of the tiles. This report presents the results of an experiment conducted at the Attock Refinery Limited (ARL) Rawalpindi to assess the performance of the antisolar insulated roof system. Record of the room temperature before and after the installation of the system shows a significant reduction in the indoor temperature. The room occupants, who used to experience a very high thermal stress after 10:30 am in spite of the 1.5-ton air conditioner operating in the room, felt much relieved after the installation. They had to turn back the thermostat of the air conditioner and even had to switch it off occasionally. A detailed thermal analysis of the room shows that cost of an antisolar system is paid back in less than a year in the form of savings of energy required for air-conditioning in summer and for gas heating in winter. In addition, the system prevents the addition of 150 kg per year of green house gases to the atmosphere for each square meter of the area covered by the system. It also provides a quieter environment by reducing the operational

  17. Establishing Green Roof Infrastructure Through Environmental Policy Instruments

    Science.gov (United States)

    Carter, Timothy; Fowler, Laurie

    2008-07-01

    Traditional construction practices provide little opportunity for environmental remediation to occur in urban areas. As concerns for environmental improvement in urban areas become more prevalent, innovative practices which create ecosystem services and ecologically functional land cover in cities will be in higher demand. Green roofs are a prime example of one of these practices. The past decade has seen the North American green roof industry rapidly expand through international green roof conferences, demonstration sites, case studies, and scientific research. This study evaluates existing international and North American green roof policies at the federal, municipal, and community levels. Green roof policies fall into a number of general categories, including direct and indirect regulation, direct and indirect financial incentives, and funding of demonstration or research projects. Advantages and disadvantages of each category are discussed. Salient features and a list of prompting standards common to successfully implemented green roof strategies are then distilled from these existing policies. By combining these features with data collected from an experimental green roof site in Athens, Georgia, the planning and regulatory framework for widespread green roof infrastructure can be developed. The authors propose policy instruments be multi-faceted and spatially focused, and also propose the following recommendations: (1) Identification of green roof overlay zones with specifications for green roofs built in these zones. This spatial analysis is important for prioritizing areas of the jurisdiction where green roofs will most efficiently function; (2) Offer financial incentives in the form of density credits and stormwater utility fee credits to help overcome the barriers to entry of the new technology; (3) Construct demonstration projects and institutionalize a commitment greening roofs on publicly-owned buildings as an effective way of establishing an educated

  18. Establishing green roof infrastructure through environmental policy instruments.

    Science.gov (United States)

    Carter, Timothy; Fowler, Laurie

    2008-07-01

    Traditional construction practices provide little opportunity for environmental remediation to occur in urban areas. As concerns for environmental improvement in urban areas become more prevalent, innovative practices which create ecosystem services and ecologically functional land cover in cities will be in higher demand. Green roofs are a prime example of one of these practices. The past decade has seen the North American green roof industry rapidly expand through international green roof conferences, demonstration sites, case studies, and scientific research. This study evaluates existing international and North American green roof policies at the federal, municipal, and community levels. Green roof policies fall into a number of general categories, including direct and indirect regulation, direct and indirect financial incentives, and funding of demonstration or research projects. Advantages and disadvantages of each category are discussed. Salient features and a list of prompting standards common to successfully implemented green roof strategies are then distilled from these existing policies. By combining these features with data collected from an experimental green roof site in Athens, Georgia, the planning and regulatory framework for widespread green roof infrastructure can be developed. The authors propose policy instruments be multi-faceted and spatially focused, and also propose the following recommendations: (1) Identification of green roof overlay zones with specifications for green roofs built in these zones. This spatial analysis is important for prioritizing areas of the jurisdiction where green roofs will most efficiently function; (2) Offer financial incentives in the form of density credits and stormwater utility fee credits to help overcome the barriers to entry of the new technology; (3) Construct demonstration projects and institutionalize a commitment greening roofs on publicly-owned buildings as an effective way of establishing an educated

  19. Underground or aboveground storage tanks - A critical decision

    International Nuclear Information System (INIS)

    Rizzo, J.A.

    1992-01-01

    With the 1988 promulgation of the comprehensive Resource Conservation and Recovery Act (RCRA) regulations for underground storage of petroleum and hazardous substances, many existing underground storage tank (UST) owners have been considering making the move to aboveground storage. While on the surface, this may appear to be the cure-all to avoiding the underground leakage dilemma, there are many other new and different issues to consider with aboveground storage. The greatest misconception is that by storing materials above ground, there is no risk of subsurface environmental problems. It should be noted that with the aboveground storage tank (AGST) systems, there is still considerable risk of environmental contamination, either by the failure of onground tank bottoms or the spillage of product onto the ground surface where it subsequently finds its way to the ground water. In addition, there are added safety concerns that must be addressed. The greatest interest in AGSTs comes from managers with small volumes of used oil, fresh oil, solvents, chemicals, or heating oil. Dealing with small capacity tanks is not so different than large bulk storage - and, in fact, it lends itself to more options, such as portable storage, tank within tank configurations and inside installations. So what are the other specific areas of concern besides environmental to be addressed when making the decision between underground and aboveground tanks? The primary issues that will be addressed in this presentation are: (1) safety; (2) product losses; (3) cost comparison of USTs vs AGSTs; (4) space availability/accessibility; (5) precipitation handling; (6) aesthetics and security; (7) pending and existing regulations

  20. Proven Alternatives for Aboveground Treatment of Arsenic in Groundwater

    Science.gov (United States)

    2002-10-01

    issue paper does not address three technologies that have been used to treat water containing arsenic: • Biological treatment • Phytoremediation ...arsenic in water, and no aboveground treatments of groundwater conducted at full scale were found. Phytoremediation and electrokinetics are not...Roundtable. September 1998. http://www.frtr.gov/costperf.htm. 1.16 U.S. EPA. Office of Research and Development. Arsenic & Mercury - Workshop on Removal

  1. Annual measurements of gain and loss in aboveground carbon density

    Science.gov (United States)

    Baccini, A.; Walker, W. S.; Carvalho, L.; Farina, M.; Sulla-menashe, D. J.; Houghton, R. A.

    2017-12-01

    Tropical forests hold large stores of carbon, but their net carbon balance is uncertain. Land use and land-cover change (LULCC) are believed to release between 0.81 and 1.14 PgC yr-1, while intact native forests are thought to be a net carbon sink of approximately the same magnitude. Reducing the uncertainty of these estimates is not only fundamental to the advancement of carbon cycle science but is also of increasing relevance to national and international policies designed to reduce emissions from deforestation and forest degradation (e.g., REDD+). Contemporary approaches to estimating the net carbon balance of tropical forests rely on changes in forest area between two periods, typically derived from satellite data, together with information on average biomass density. These approaches tend to capture losses in biomass due to deforestation (i.e., wholesale stand removals) but are limited in their sensitivity to forest degradation (e.g., selective logging or single-tree removals), which can account for additional biomass losses on the order of 47-75% of deforestation. Furthermore, while satellite-based estimates of forest area loss have been used successfully to estimate associated carbon losses, few such analyses have endeavored to determine the rate of carbon sequestration in growing forests. Here we use 12 years (2003-2014) of pantropical satellite data to quantify net annual changes in the aboveground carbon density of woody vegetation (MgC ha-1yr-1), providing direct, measurement-based evidence that the world's tropical forests are a net carbon source of 425.2 ± 92.0 Tg C yr-1. This net release of carbon consists of losses of 861.7 ± 80.2 Tg C yr-1 and gains of -436.5 ± 31.0 Tg C yr-1 . Gains result from forest growth; losses result from reductions in forest area due to deforestation and from reductions in biomass density within standing forests (degradation), with the latter accounting for 68.9% of overall losses. Our findings advance previous research

  2. Installation of a Roof Mounted Photovoltaic System

    Science.gov (United States)

    Lam, M.

    2015-12-01

    In order to create a safe and comfortable environment for students to learn, a lot of electricity, which is generated from coal fired power plants, is used. Therefore, ISF Academy, a school in Hong Kong with approximately 1,500 students, will be installing a rooftop photovoltaic (PV) system with 302 solar panels. Not only will these panels be used to power a classroom, they will also serve as an educational opportunity for students to learn about the importance of renewable energy technology and its uses. There were four different options for the installation of the solar panels, and the final choice was made based on the loading capacity of the roof, considering the fact that overstressing the roof could prove to be a safety hazard. Moreover, due to consideration of the risk of typhoons in Hong Kong, the solar panel PV system will include concrete plinths as counterweights - but not so much that the roof would be severely overstressed. During and after the installation of the PV system, students involved would be able to do multiple calculations, such as determining the reduction of the school's carbon footprint. This can allow students to learn about the impact renewable energy can have on the environment. Another project students can participate in includes measuring the efficiency of the solar panels and how much power can be produced per year, which in turn can help with calculate the amount of money saved per year and when we will achieve economic parity. In short, the installation of the roof mounted PV system will not only be able to help save money for the school but also provide learning opportunities for students studying at the ISF Academy.

  3. Roof timber for fortifying mining works

    Energy Technology Data Exchange (ETDEWEB)

    Shirokov, A P; Kuntsevich, V IK; Pishchulin, V V; Seryi, A M; Volkov, P A

    1981-05-15

    The roof timber for fortifying mining works includes spring-mounted hinged elements made from a special rolled metal. In order to increase the carrying capacity of the support by increasing the deformation threshold, the springs are mounted by their expanded section to the lower side of the hinge; their ends are connected in turn to the elements made from the special rolled metal on both sides of the hinge.

  4. Using soil microbial inoculations to enhance substrate performance on extensive green roofs.

    Science.gov (United States)

    Molineux, Chloe J; Gange, Alan C; Newport, Darryl J

    2017-02-15

    Green roofs are increasing in popularity in the urban environment for their contribution to green infrastructure; but their role for biodiversity is not often a design priority. Maximising biodiversity will impact positively on ecosystem services and is therefore fundamental for achieving the greatest benefits from green roofs. Extensive green roofs are lightweight systems generally constructed with a specialised growing medium that tends to be biologically limited and as such can be a harsh habitat for plants to thrive in. Thus, this investigation aimed to enhance the soil functioning with inoculations of soil microbes to increase plant diversity, improve vegetation health/performance and maximise access to soil nutrients. Manipulations included the addition of mycorrhizal fungi and a microbial mixture ('compost tea') to green roof rootzones, composed mainly of crushed brick or crushed concrete. The study revealed that growing media type and depth play a vital role in the microbial ecology of green roofs, with complex relationships between depth and type of substrate and the type of microbial inoculant applied, with no clear pattern being observed. For bait plant measurements (heights, leaf numbers, root/shoot biomass, leaf nutrients), a compost tea may have positive effects on plant performance when grown in substrates of shallower depths (5.5cm), even one year after inoculums are applied. Results from the species richness surveys show that diversity was significantly increased with the application of an AM fungal treatment and that overall, results suggest that brick-based substrate blends are most effective for vegetation performance as are deeper depths (although this varied with time). Microbial inoculations of green roof habitats appeared to be sustainable; they need only be done once for benefits to still been seen in subsequent years where treatments are added independently (not in combination). They seem to be a novel and viable method of enhancing

  5. A zero discharge green roof system and species selection to optimize evapotranspiration and water retention

    Energy Technology Data Exchange (ETDEWEB)

    Compton, J.S.; Whitlow, T.H. [Cornell, Univ., Urban Horticulture Inst., Ithaca, NY (United States). Dept. of Horticulture

    2006-07-01

    Economic benefits must outweigh costs, with or without governmental subsidies or enforcement in order for green roofs to become commonplace in American cities. Municipal advantages to green roofs include stormwater management, environmental quality and an expansion of the native plant palette. These benefits are difficult to quantify monetarily for the owner of the roof, yet greater water evaporation from storm water attenuation has the ability to increase cooling of the building, an economic benefit to the owner. Current green roof design and testing methods fail to explore systems that maximize stormwater retention and evaporative cooling benefits that are often associated with green roofs. This paper presented the results of a study that investigated an alternate approach that optimizes water loss through evapotranspiration using a zero discharge target and plants that tolerate both medium drought and saturation. Species selection emphasizes native species and salt tolerance, which allows the possibility of grey water irrigation. Species studied include spartina alternafiora and solidago canadensis. Plants were studied over a growing season to examine the rates of ET as they relate to weather conditions, growing media composition and saturation levels, and plant species. The study was conducted on top of a four storey school building located in the South Bronx, New York City. In June 2005, a 3,500 square foot extensive green roof was installed. The conference described the site and study in detail followed by a discussion of the results. This includes a discussion of the planting containers, planting mediums, plant materials, data collection, and irrigation trials. It was concluded that further research is needed to test this concept, and to examine the possibility of supplemental irrigation via off-season rainwater catchment or grey water irrigation. 17 refs., 4 figs.

  6. The hydrological behaviour of extensive and intensive green roofs in a dry climate.

    Science.gov (United States)

    Razzaghmanesh, M; Beecham, S

    2014-11-15

    This paper presents the results of a hydrological investigation of four medium scale green roofs that were set up at the University of South Australia. In this study, the potential of green roofs as a source control device was investigated over a 2 year period using four medium size green roof beds comprised of two growth media types and two media depths. During the term of this study, 226 rainfall events were recorded and these were representative of the Adelaide climate. In general, there were no statistically significant differences between the rainfall and runoff parameters for the intensive and extensive beds except for peak attenuation and peak runoff delay, for which higher values were recorded in the intensive beds. Longer dry periods generally resulted in higher retention coefficients and higher retention was also recorded in warmer seasons. The average retention coefficient for intensive systems (89%) was higher than for extensive systems (74%). It was shown that rainfall depth, intensity, duration and also average dry weather period between events can change the retention performance and runoff volume of the green roofs. Comparison of green and simulated conventional roofs indicated that the former were able to mitigate the peak of runoff and could delay the start of runoff. These characteristics are important for most source control measures. The recorded rainfall and runoff data displayed a non-linear relationship. Also, the results indicated that continuous time series modelling would be a more appropriate technique than using peak rainfall intensity methods for green roof design and simulation. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. The variable effects of soil nitrogen availability and insect herbivory on aboveground and belowground plant biomass in an old-field ecosystem

    DEFF Research Database (Denmark)

    Blue, Jarrod D.; Souza, Lara; Classen, Aimée T.

    2011-01-01

    in an old-field ecosystem. In 2004, we established 36 experimental plots in which we manipulated soil nitrogen (N) availability and insect abundance in a completely randomized plot design. In 2009, after 6 years of treatments, we measured aboveground biomass and assessed root production at peak growth...... not be limiting primary production in this ecosystem. Insects reduced the aboveground biomass of subdominant plant species and decreased coarse root production. We found no statistical interactions between N availability and insect herbivory for any response variable. Overall, the results of 6 years of nutrient...

  8. EVALUATION OF ROOF BOLTING REQUIREMENTS BASED ON IN-MINE ROOF BOLTER DRILLING

    Energy Technology Data Exchange (ETDEWEB)

    Syd S. Peng

    2005-01-15

    In this quarter, the field, theoretical and programming works have been performed toward achieving the research goals set in the proposal. The main accomplishments in this quarter included: (1) one more field test has been conducted in an underground coal mine, (2) optimization studies of the control parameters have been conducted, (3) method to use torque to thrust ratio as indicator of rock relative hardness has also been explored, and (4) about 98% of the development work for the roof geology mapping program, MRGIS, has completed, (5) A real time roof geology mapping system for roof bolters in limestone mine, including a special version of the geology mapping program and hardware, has already been verified to perform very well in underground production condition.

  9. Biochar increases plant growth and alters microbial communities via regulating the moisture and temperature of green roof substrates.

    Science.gov (United States)

    Chen, Haoming; Ma, Jinyi; Wei, Jiaxing; Gong, Xin; Yu, Xichen; Guo, Hui; Zhao, Yanwen

    2018-09-01

    Green roofs have increasingly been designed and applied to relieve environmental problems, such as water loss, air pollution as well as heat island effect. Substrate and vegetation are important components of green roofs providing ecosystem services and benefiting the urban development. Biochar made from sewage sludge could be potentially used as the substrate amendment for green roofs, however, the effects of biochar on substrate quality and plant performance in green roofs are still unclear. We evaluated the effects of adding sludge biochar (0, 5, 10, 15 and 20%, v/v) to natural soil planted with three types of plant species (ryegrass, Sedum lineare and cucumber) on soil properties, plant growth and microbial communities in both green roof and ground ecosystems. Our results showed that sludge biochar addition significantly increased substrate moisture, adjusted substrate temperature, altered microbial community structure and increased plant growth. The application rate of 10-15% sludge biochar on the green roof exerted the most significant effects on both microbial and plant biomass by 63.9-89.6% and 54.0-54.2% respectively. Path analysis showed that biochar addition had a strong effect on microbial biomass via changing the soil air-filled porosity, soil moisture and temperature, and promoted plant growth through the positive effects on microbial biomass. These results suggest that the applications of biochar at an appropriate rate can significantly alter plant growth and microbial community structure, and increase the ecological benefits of green roofs via exerting effects on the moisture, temperature and nutrients of roof substrates. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Variations of PV Panel Performance Installed over a Vegetated Roof and a Conventional Black Roof

    Directory of Open Access Journals (Sweden)

    Mohammed J. Alshayeb

    2018-05-01

    Full Text Available The total worldwide photovoltaic (PV capacity has been growing from about 1 GW at the beginning of the twenty-first century to over 300 GW in 2016 and is expected to reach 740 GW by 2022. PV panel efficiency is reported by PV manufacturers based on laboratory testing under Standard Testing Condition with a specific temperature of 25 °C and solar irradiation of 1000 W/m2. This research investigated the thermal interactions between the building roof surface and PV panels by examining the differences in PV panel temperature and energy output for those installed over a green roof (PV-Green and those installed over a black roof (PV-Black. A year-long experimental study was conducted over the roof of an educational building with roof mounted PV panels with a system capacity of 4.3 kW to measure PV underside surface temperature (PV-UST, ambient air temperature between PV panel and building roof (PV-AT, and PV energy production (PV-EP. The results show that during the summer the PV-Green consistently recorded lower PV-UST and PV-AT temperatures and more PV-EP than PV-Black. The average hourly PV-EP difference was about 0.045 kWh while the maximum PV-EP difference was about 0.075 kWh, which represents roughly a 3.3% and 5.3% increase in PV-EP. For the entire study period, EP-Green produced 19.4 kWh more energy, which represents 1.4% more than EP-Black.

  11. Results for the Aboveground Configuration of the Boiling Water Reactor Dry Cask Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Durbin, Samuel G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lindgren, Eric R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-09-30

    The thermal performance of commercial nuclear spent fuel dry storage casks is evaluated through detailed numerical analysis. These modeling efforts are completed by the vendor to demonstrate performance and regulatory compliance. The calculations are then independently verified by the Nuclear Regulatory Commission (NRC). Carefully measured data sets generated from testing of full-sized casks or smaller cask analogs are widely recognized as vital for validating these models. Recent advances in dry storage cask designs have significantly increased the maximum thermal load allowed in a cask, in part by increasing the efficiency of internal conduction pathways, and also by increasing the internal convection through greater canister helium pressure. These same canistered cask systems rely on ventilation between the canister and the overpack to convect heat away from the canister to the environment for both above- and below-ground configurations. While several testing programs have been previously conducted, these earlier validation attempts did not capture the effects of elevated helium pressures or accurately portray the external convection of above-ground and below-ground canistered dry cask systems. The purpose of the current investigation was to produce data sets that can be used to test the validity of the assumptions associated with the calculations used to determine steady-state cladding temperatures in modern dry casks that utilize elevated helium pressure in the sealed canister in an above-ground configuration.

  12. Application of solar roof shallow pool at individual residental buildings

    OpenAIRE

    Gavrilović Dragan J.

    2011-01-01

    The paper discusses the possibility of applying shallow roof pools of water on the basis of passive solar water capture functioning as thermal batteries and thermal "regulators" in a "hot - cold" mode with individual residential buildings. With this application, the utilization of the existing functionality of the building roof area would improve and open up the possibility of achieving better overall bio-climate individual object. By using this system, a flat roof impassable "terrace" ...

  13. The Self-Drying Concept for Flat Roofs

    DEFF Research Database (Denmark)

    Korsgaard, Vagn; Bunch-Nielsen, Tommy; Rode, Carsten

    1996-01-01

    ways. From the interior by diffusion and convection. During construction from moist materials or rain. Later on, rain water may enter through leaks in the roofing.From laboratory experiment, computer calculations and practical experience it is concluded, that the Self-Drying Roof concept works for both...... cold- and warm deck roof systems in climate zones where a vapor retarder is needed, if the traditional water proof vapor retarder is substituted by a water permeable vapor retarder....

  14. Fixing Trailer Hitch for Roof Rack of Cargos

    Directory of Open Access Journals (Sweden)

    Darina Matisková

    2017-02-01

    Full Text Available This article presents a new technical solution of fixing trailer hitch which serves as a connection between single track vehicle and cargo, mainly light trailer. They are manufactured from steel girder and nets which are constructed by point welding. They are designed to indicate the necessary solidity and the required load bearing capacity of the cargo. The application of roof racks is universal and these products are in great demand in the field of game management. There are a lot of trailer hitches which the manufacturers tailor to customers´ demands. The stated technical solution is subject of published industrial utility model at the Industrial property office of the Slovak republic.

  15. Fire resistance of single pitched-roof steel portal frame

    Directory of Open Access Journals (Sweden)

    J. J. Ferrán Gozálvez

    2017-03-01

    Full Text Available The standard procedure of structural fire design is based on the simplified analysis of single members. This method leads to conservative results in the case of structures able to redistribution of forces. The failure mechanism affecting both life safety and fire propagation is unknown. This work proposes a methodology for the advanced fire calculation of single pitched-roof portal frame for an agroindustrial building according to the Spanish Specifications with the structural software SAP2000. A non-linear dynamic and plastic, geometric (P-Delta and large-displacements calculation method has been developed. The different failure mechanisms and their influence are studied in terms of fire time resistance, human hazard and good safety. Also, parametric analyses were conducted: load level, rotational stiffness of the base and finally, support fire protection.

  16. Phosphate Leaching from Green Roof Substrates—Can Green Roofs Pollute Urban Water Bodies?

    Directory of Open Access Journals (Sweden)

    Agnieszka Karczmarczyk

    2018-02-01

    Full Text Available Green roofs are an effective stormwater measure due to high water retention capacity and the ability of delaying stormwater runoff. However, low importance is still given to the pollutant leaching potential of substrates used in green roof construction. The aim of the study is to estimate the concentrations and loads of P-PO43− in runoff from extensive and intensive substrates. To achieve this goal, several commonly-used fresh substrates were analyzed for P-PO43− leaching potential in different scale experiments, from laboratory batch tests, leaching column experiments, and long-term monitoring of open air green roof containers. The results of the study confirmed that fresh green roof substrates contain phosphorus in significant amounts of 17–145 mg∙P-PO43−/kg and, thus, can contribute to eutrophication of freshwater ecosystems. High correlation between phosphate content estimated by HCl extraction and cumulative load in leachate tests suggests that the batch HCl extraction test can be recommended for the comparison and selection of substrates with low potential P leaching. Volume-weighted mean concentrations and UALs of P-PO43− leaching from fresh substrates were higher in cases of intensive substrates, but there was no clear relationship between substrate type and the observed P-PO43− concentration range. To avoid increasing eutrophication of urban receivers the implementation of P reduction measures is strongly recommended.

  17. Roof renovation of buildings 128 and 129

    CERN Multimedia

    2015-01-01

    The roof renovation of buildings 128 and 129 is scheduled to take place from 17 August to 15 October 2015.   During this period, access to the "raw material" workshop will be limited and controlled due to asbestos removal. Collecting your orders directly from the building will be difficult, or even impossible, and urgent requests will be difficult to carry out. We therefore ask you to create your requests via EDH, so that delivery may be carried out as soon as possible. Thank you for your understanding. GS Department

  18. Time focused measurements of roof runoff quality

    International Nuclear Information System (INIS)

    Schriewer, A.; Horn, H.; Helmreich, B.

    2008-01-01

    Runoff properties and their changes during runoff of a 14 year old zinc roof were investigated. Zinc, lead, cadmium, pH value, rain intensity and electric conductivity have been measured for a period of one year. A runoff rate of 3.73 g/m 2 a and a volume weighted mean zinc concentration of 4.9 mg/L were determined. First flush behaviour was observed in 93% of runoff events. Low rain intensities are correlating with higher zinc concentrations in runoff, whereas the duration of antecedent dry periods could not directly be linked with initial zinc concentrations

  19. Effective roof support for tabular stopes.

    CSIR Research Space (South Africa)

    Ottermann, RW

    2002-09-01

    Full Text Available hydraulic press of the servo hydraulic test facility of the University of Pretoria. The yielding mechanism was compressed at a constant speed of 10 mm/min and the force displacement characteristics was recorded. See figure 4-18. After reaching... damper absorbing the forces. The test of the yielding mechanism was done in a servo hydraulic press as described in paragraph 4.4.2. 5.1.2 Laboratory tests The load cycle chosen for the testing of the structure of the roof support system was: 5...

  20. Empirical and theoretical challenges in aboveground-belowground ecology

    DEFF Research Database (Denmark)

    W.H. van der Putten,; R.D. Bardgett; P.C. de Ruiter

    2009-01-01

    of the current conceptual succession models into more predictive models can help targeting empirical studies and generalising their results. Then, we discuss how understanding succession may help to enhance managing arable crops, grasslands and invasive plants, as well as provide insights into the effects...... and environmental settings, we explore where and how they can be supported by theoretical approaches to develop testable predictions and to generalise empirical results. We review four key areas where a combined aboveground-belowground approach offers perspectives for enhancing ecological understanding, namely...

  1. Decomposition of aboveground biomass of a herbaceous wetland stand

    OpenAIRE

    KLIMOVIČOVÁ, Lucie

    2010-01-01

    The master?s thesis is part of the project GA ČR č. P504/11/1151- Role of plants in the greenhouse gas budget of a sedge fen. This thesis deals with the decomposition of aboveground vegetation in a herbaceous wetland. The decomposition rate was established on the flooded part of the Wet Meadows near Třeboň. The rate of the decomposition processes was evaluated using the litter-bag method. Mesh bags filled with dry plant matter were located in the vicinity of the automatic meteorological stati...

  2. Closure Report for Corrective Action Unit 134: Aboveground Storage Tanks, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    2009-01-01

    Corrective Action Unit (CAU) 134 is identified in the Federal Facility Agreement and Consent Order (FFACO) as 'Aboveground Storage Tanks' and consists of the following four Corrective Action Sites (CASs), located in Areas 3, 15, and 29 of the Nevada Test Site: (1) CAS 03-01-03, Aboveground Storage Tank; (2) CAS 03-01-04, Tank; (3) CAS 15-01-05, Aboveground Storage Tank; and (4) CAS 29-01-01, Hydrocarbon Stain

  3. Diesel oil pool fire characteristic under natural ventilation conditions in tunnels with roof openings.

    Science.gov (United States)

    Wang, Yanfu; Jiang, Juncheng; Zhu, Dezhi

    2009-07-15

    In order to research the fire characteristic under natural ventilation conditions in tunnels with roof openings, full-scale experiment of tunnel fire is designed and conducted. All the experimental data presented in this paper can be further applied for validation of numerical simulation models and reduced-scale experimental results. The physical model of tunnel with roof openings and the mathematical model of tunnel fire are presented in this paper. The tunnel fire under the same conditions as experiment is simulated using CFD software. From the results, it can be seen that most smoke is discharged directly off the tunnel through roof openings, so roof openings are favorable for exhausting smoke. But along with the decrease of smoke temperatures, some smoke may backflow and mix with the smoke-free layer below, which leads to fall in visibility and is unfavorable for personnel evacuation. So it is necessary to research more efficient ways for improving the smoke removal efficiency, such as early fire detection systems, adequate warning signs and setting tunnel cap.

  4. Modelling runoff on ceramic tile roofs using the kinematic wave equations

    Science.gov (United States)

    Silveira, Alexandre; Abrantes, João; de Lima, João; Lira, Lincoln

    2016-04-01

    Rainwater harvesting is a water saving alternative strategy that presents many advantages and can provide solutions to address major water resources problems, such as fresh water scarcity, urban stream degradation and flooding. In recent years, these problems have become global challenges, due to climatic change, population growth and increasing urbanisation. Generally, roofs are the first to come into contact with rainwater; thus, they are the best candidates for rainwater harvesting. In this context, the correct evaluation of roof runoff quantity and quality is essential to effectively design rainwater harvesting systems. Despite this, many studies usually focus on the qualitative aspects in detriment of the quantitative aspects. Laboratory studies using rainfall simulators have been widely used to investigate rainfall-runoff processes. These studies enabled a detailed exploration and systematic replication of a large range of hydrologic conditions, such as rainfall spatial and temporal characteristics, providing for a fast way to obtain precise and consistent data that can be used to calibrate and validate numerical models. This study aims to evaluate the performance of a kinematic wave based numerical model in simulating runoff on sloping roofs, by comparing the numerical results with the ones obtained from laboratory rainfall simulations on a real-scale ceramic tile roof (Lusa tiles). For all studied slopes, simulated discharge hydrographs had a good adjust to observed ones. Coefficient of determination and Nash-Sutcliffe efficiency values were close to 1.0. Particularly, peak discharges, times to peak and peak durations were very well simulated.

  5. Differential substrate subsidence of the EnviHUT project pitched extensive green roof

    Directory of Open Access Journals (Sweden)

    Nečadová Klára

    2017-01-01

    Full Text Available In primary phase of testing building physical characteristics of the EnviHUT project extensive and semi-intensive roofs with 30° inclination occurred exceptional substrate subsidence. An extensive testing field with retaining geocell-system evinced differential subsidence of individual sectors after six months. Measured subsidence of installed substrate reached 40 % subsidence compared to originally designed height (intended layer thickness. Subsequent deformation of geocell-system additionally caused partial slide of substrate to drip edge area. These slides also influenced initial development of stonecrop plants on its surface. Except functional shortages the aesthetical function of the whole construction is influenced by the mentioned problem. The stated paper solves mentioned issues in view of installation method optimization, selection and modification of used roof substrate and in view of modification of geometric and building installed elements retaining system arrangement. Careful adjustment of roof system geometry and enrichment of original substrate fraction allow full functionality from pitched extensive green roof setting up. The modification scheme and its substantiation is a part of this technical study output.

  6. A graph edit dictionary for correcting errors in roof topology graphs reconstructed from point clouds

    Science.gov (United States)

    Xiong, B.; Oude Elberink, S.; Vosselman, G.

    2014-07-01

    In the task of 3D building model reconstruction from point clouds we face the problem of recovering a roof topology graph in the presence of noise, small roof faces and low point densities. Errors in roof topology graphs will seriously affect the final modelling results. The aim of this research is to automatically correct these errors. We define the graph correction as a graph-to-graph problem, similar to the spelling correction problem (also called the string-to-string problem). The graph correction is more complex than string correction, as the graphs are 2D while strings are only 1D. We design a strategy based on a dictionary of graph edit operations to automatically identify and correct the errors in the input graph. For each type of error the graph edit dictionary stores a representative erroneous subgraph as well as the corrected version. As an erroneous roof topology graph may contain several errors, a heuristic search is applied to find the optimum sequence of graph edits to correct the errors one by one. The graph edit dictionary can be expanded to include entries needed to cope with errors that were previously not encountered. Experiments show that the dictionary with only fifteen entries already properly corrects one quarter of erroneous graphs in about 4500 buildings, and even half of the erroneous graphs in one test area, achieving as high as a 95% acceptance rate of the reconstructed models.

  7. The psychological and physiological stress relief effect of the green roof

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H.; Koshimizu, H. [Meiji Univ., Tokyo (Japan). Dept. of Agriculture

    2007-07-01

    The visual sense influences human psychology and physiology. As such, green gardens in urban environments are touted as being healing gardens that lead to stress relief and improved work efficiency. This paper focused on the visual aspects of such rehabilitation sites. Psychological and physiological experiments were conducted on human response to green roofs in order to quantify the stress relief effect of the green roof scenery. In addition, different green roof designs were tested to determine whether they change the stress relief effect. A 360 degrees panorama photograph of green roofs was shown to 3 male and 3 female students in Meiji University. The experiment was followed by a questionnaire survey based on the semantic differential (SD) method as a psychological evaluation. The SD method is a representative psychological measurement to quantify an image of people for a scene. The changes in heart rate were studied along with blood pressure, and stress degree as a physiological evaluation. The relation between the results of the SD method-based psychological evaluation and the physiological experiment was determined using multiple regression analysis. It was concluded that the stress relief effect can be improved by changing linear scenery to a more curvy one. 15 refs., 4 tabs., 20 figs.

  8. Air-quality implications of widespread adoption of cool roofs on ozone and particulate matter in southern California

    Science.gov (United States)

    Ban-Weiss, G. A.; Lee, S. M.; Katzenstein, A. S.; Carreras-Sospedra, M.; Zhang, X.; Farina, S.; Vahmani, P.; Fine, P.; Epstein, S. A.

    2017-12-01

    The installation of roofing materials with increased solar reflectance (i.e., "cool roofs") can mitigate the urban heat island effect and reduce energy use. In addition, meteorological changes, along with the possibility of enhanced UV reflection from these surfaces, can have complex impacts on ozone and PM2.5 concentrations. We aim to evaluate the air-quality impacts of widespread cool-roof installations prescribed by building energy efficiency standards within the heavily populated and polluted South Coast Air Basin (SoCAB) in Southern California. Development of a comprehensive rooftop area database and evaluation of spectral reflectance measurements of roofing materials allows us to predict potential future changes in solar and UV reflectance for simulations using the Weather Research Forecast and Community Multiscale Air Quality (CMAQ) models. Meteorological simulations indicate a decrease in daily maximum temperatures, daily maximum boundary layer heights, and ventilation coefficients throughout the SoCAB upon widespread installation of cool roofs. CMAQ simulations show significant increases in PM2.5 concentrations and policy-relevant design values. Changes in 8-h ozone concentrations depend on the potential change in UV reflectance, ranging from a decrease in population-weighted concentrations when UV reflectance remains unchanged to an increase when changes in UV reflectance are at an upper bound. However, 8-h policy-relevant ozone design values increase in all cases. Although the other benefits of cool roofs could outweigh small air-quality penalties, UV reflectance standards for cool roofing materials could mitigate these negative consequences. Results of this study motivate the careful consideration of future rooftop and pavement solar reflectance modification policies.

  9. Structure, Aboveground Biomass, and Soil Characterization of Avicennia marina in Eastern Mangrove Lagoon National Park, Abu Dhabi

    Science.gov (United States)

    Alsumaiti, Tareefa Saad Sultan

    Mangrove forests are national treasures of the United Arab Emirates (UAE) and other arid countries with limited forested areas. Mangroves form a crucial part of the coastal ecosystem and provide numerous benefits to society, economy, and especially the environment. Mangrove trees, specifically Avicennia marina, are studied in their native habitat in order to characterize their population structure, aboveground biomass, and soil properties. This study focused on Eastern Mangrove Lagoon National Park in Abu Dhabi, which was the first mangrove protected area to be designated in UAE. In situ measurements were collected to estimate Avicennia marina status, mortality rate (%), height (m), crown spread (m), stem number, diameter at breast height (cm), basal area (m), and aboveground biomass (t ha-1 ). Small-footprint aerial light detection and ranging (LIDAR) data acquired by UAE were processed to characterize mangrove canopy height and aboveground biomass density. This included extraction of LIDAR-derived height percentile statistics, segmentation of the forest into structurally homogenous units, and development of regression relationships between in situ reference and remote sensing data using a machine learning approach. An in situ soil survey was conducted to examine the soils' physical and chemical properties, fertility status, and organic matter. The data of soil survey were used to create soil maps to evaluate key characteristics of soils, and their influence on Avicennia marina in Eastern Mangrove Lagoon National Park. The results of this study provide new insights into Avicennia marina canopy population, structure, aboveground biomass, and soil properties in Abu Dhabi, as data in such arid environments is lacking. This valuable information can help in managing and preserving this unique ecosystem.

  10. Transparent but not open: glass roof of the courtyard of the Provinciehuis (provincial government building in Groningen

    Directory of Open Access Journals (Sweden)

    Michiel S. Verweij

    2008-04-01

    The late medieval Sint Maartens-school is the oldest building. Later additions are a record office from 1880-1881 (architect J. van Lokhorst, a wing dating from 1915-1917 (architect J.A.W. Vrijman and a caretaker's house also dating from 1915-1917. but executed with a facade from 1559 originating from another part of the city. The complex has two courtyards: one bearing the prosaic name Grote Snor. originally an alley between Singelstraat and Martinikerkhof, and one courtyard in the form of an isosceles triangle. This second courtyard was provided with a transparent roof in 2006. As the buildings on the second courtyard are all on the national monuments and historic buildings register, the Rijksdienst voor Archeologie. Cultuurlandschap en Monumenten (RACM played an advisory role in the planning preceding the execution. The RACM could agree to the principle of roofing. The courtyard had not been designed as such but had come into being because buildings had been erected in various periods and at a certain moment an interjacent plot was left. This residual space looked abandoned and was not part of the activity of the Provinciehuis, whereas in the year 2004 there was a need for extra floor area and a representative space. When the courtyard would be covered, these wishes could be fulfilled. The RACM served the municipality of Groningen, being the licence-issuing authority, with the following range of thought: a roof should not cause any material or constructive damage to the listed buildings; a transparent roof is to be preferred and ought to be subordinate to the historical architecture; as a result of the roof the courtyard will acquire a new and vital role in the official duties of the Provinciehuis; the users would be able to see. appreciate and enjoy the adjoining listed buildings better from the courtyard; roofing undoubtedly contributes to more intensive, improved use. and as a result, to the future value of the listed buildings. In addition, the RACM

  11. Effects of roof tile permeability on the thermal performance of ventilated roofs. Analysis of annual performance

    Energy Technology Data Exchange (ETDEWEB)

    D' Orazio, M.; Di Perna, C.; Principi, P.; Stazi, A. [DACS, Universita politecnica delle Marche, 60100 Ancona (Italy)

    2008-07-01

    This paper shows the results of the second part of an experimental study aimed at analysing the effects of roof tile permeability on the thermal performances of ventilation ducts. Ventilation ducts under the layer of tiles are typically used in south European countries to limit the energy load during the summer period. The results of the first part of the study, carried out by analysing 14 different types of roof, proved that the air permeability of the layer of tiles determines a certain amount of heat to be released, in addition to the release connected with the stack effect, in ventilation ducts which have the same characteristics but are perfectly airtight. However, the study did not completely resolve some issues since it was carried out on a model roof (6 m x 1.5 m) with devices to raise the layer of tiles and to create the ventilation duct but without those building elements which are present in real roofs and are used to stop insects and small animals from entering the ventilation duct. These elements narrow the inlet and outlet and consequently cause important reductions in pressure. Moreover, the measurements were based on data collected for limited periods of time during the summer season. So as to eliminate any possible uncertainty from the results of the research, the study continued with the creation of a model building on which five types of ventilated roof with different cross sections of the ventilation duct were analysed. The results show that the presence of air permeable layers and elements to protect the ventilation duct eliminate any differences in performance which were due to the cross section of the ventilation duct. (author)

  12. Life cycle assessment of roof integrated solar cell systems

    International Nuclear Information System (INIS)

    Van Brummelen, M.; Nieuwlaar, E.

    1994-01-01

    The research protocol, applied in this report, is designed for use within the energy R and D-context: it provides a framework for finding bottlenecks and opportunities for (new) energy technologies in the context of (energy) resource scarcity and environmental issues. Finding and analyzing these bottlenecks and opportunities is a major objective of this study. A derived objective of this study is to gain experience in using the LCA-framework and the research protocol described earlier, and to evaluate the usefulness of these instruments in helping to find and analyze bottlenecks and opportunities in energy technologies. Photovoltaic solar cell systems (PV systems) are comprised of solar cell modules and a Balance-of-System (BOS): a support structure and power conditioning equipment. In this LCA amorphous silicon cells (a-Si) are considered. For the Netherlands roof-integrated, grid-connected systems are assumed to be the major application of PV in the future. Two cases will be studied. In case 1 a system of 30 m 2 of modules which are connected to the grid via a single inverter are studied. The modules are comprised of a-Si cells and have a conversion efficiency of 10%. Integration into the roof is done with aluminium profiles. In case 2 a system of 30 m 2 a-Si cell modules integrated in the roof with plastic 'tiles' is studied. The modules have an efficiency of 15% and connection to the grid is more or less centralized: 25 systems share an inverter which is connected to the grid. The goal and scope of the LCA and the functional unit are described in chapter 2. In chapter 3 the process tree and descriptions of the distinguished processes are given and the inventory table is drawn up. In chapter 4 the impact assessment is dealt with, followed by a discussion of improvement options in chapter 5. Conclusions and recommendations are given in the chapters 6 and 7 only regarding the environmental aspects. 9 figs., 13 tabs., 4 appendices, 13 refs

  13. TASK 2.5.7 FIELD EXPERIMENTS TO EVALUATE COOL-COLORED ROOFING

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William A [ORNL; Cherry, Nigel J [ORNL; Allen, Richard Lowell [ORNL; Childs, Phillip W [ORNL; Atchley, Jerald Allen [ORNL; Ronnen, Levinson [Lawrence Berkeley National Laboratory (LBNL); Akbari, Hashem [Lawrence Berkeley National Laboratory (LBNL); Berhahl, Paul [Lawrence Berkeley National Laboratory (LBNL)

    2010-03-01

    counter battens, providing a nailing surface for the concrete tile. This double batten construction forms an inclined air channel running from the soffit to the ridge. The bottom surface of the channel is formed by the roof decking and is relatively flat and smooth. The top surface is created by the underside of the roofing tiles, and is designed to be an air permeable covering to alleviate the underside air pressure and minimize wind uplift on the tiles. The resulting air flows also have a cooling influence which further complicates prediction of the heat penetrating through the deck because an accurate measure of the airflow is required to predict the heat transfer. Measured temperatures and heat flows at the roof surface, within the attic and at the ceiling of the houses are discussed as well as the power usage to help gauge the benefit of cool-pigmented reflective roof products fitted with and without ventilation above the roof deck. Ventilation occurring above the deck is an inherent feature for tile roof assemblies, and is formed by an air space between the exterior face of the roof sheathing and the underside of the tile. The greater the tile s profile the greater is the effect of the ventilation which herein is termed above-sheathing ventilation (ASV). However, because of the complexity of the thermally induced flow, little credit is allowed by state and federal building codes. ASHRAE (2005) provides empirical data for the effective thermal resistance of plane air spaces. A -in. (0.0191-m) plane air space inclined at 45 with the horizontal has an RUS-0.85 (RSI-0.15) . Our intent is to help further deploy cool color pigments in roofs by conducting field experiments to evaluate the new cool-colored roofing materials in the hot climate of Southern California. The collected data will be used to showcase and market the performance of new cool-roof products and also to help formulate and validate computer codes capable of calculating the heat transfer occurring within

  14. A Roof for the Lion's House

    Science.gov (United States)

    1978-01-01

    Fans of the National Football League's Detroit Lions don't worry about gameday weather. Their magnificent new Pontiac Stadium has a domed, air-supported, fabric roof that admits light but protects the playing field and patrons from the elements. The 80,000-seat "Silverdome" is the world's largest fabric-covered structure-and aerospace technology played an important part in its construction. The key to economical construction of the Silverdome-and many other types of buildings-is a spinoff of fiber glass Beta yarn coated with Teflon TFE fluorocarbon resin. The big advance it offers is permanency. Fabric structures-tents, for example have been around since the earliest years of human civilization. But their coverings-hides, canvas and more recently plastics-were considered temporary; though tough, these fabrics were subject to weather deterioration. Teflon TFE-coated Beta Fiberglas is virtually impervious to the effects of weather and sunlight and it won't stretch, shrink, mildew or rot, thus has exceptional longevity; it is also very strong, lightweight, flame resistant and requires no periodic cleaning, because dirt will not stick to the surface of Teflon TFE. And to top all that, it costs only 30 to 40 percent as much as conventional roofing.

  15. Aboveground insect infestation attenuates belowground Agrobacterium-mediated genetic transformation.

    Science.gov (United States)

    Song, Geun Cheol; Lee, Soohyun; Hong, Jaehwa; Choi, Hye Kyung; Hong, Gun Hyong; Bae, Dong-Won; Mysore, Kirankumar S; Park, Yong-Soon; Ryu, Choong-Min

    2015-07-01

    Agrobacterium tumefaciens causes crown gall disease. Although Agrobacterium can be popularly used for genetic engineering, the influence of aboveground insect infestation on Agrobacterium induced gall formation has not been investigated. Nicotiana benthamiana leaves were exposed to a sucking insect (whitefly) infestation and benzothiadiazole (BTH) for 7 d, and these exposed plants were inoculated with a tumorigenic Agrobacterium strain. We evaluated, both in planta and in vitro, how whitefly infestation affects crown gall disease. Whitefly-infested plants exhibited at least a two-fold reduction in gall formation on both stem and crown root. Silencing of isochorismate synthase 1 (ICS1), required for salicylic acid (SA) synthesis, compromised gall formation indicating an involvement of SA in whitefly-derived plant defence against Agrobacterium. Endogenous SA content was augmented in whitefly-infested plants upon Agrobacterium inoculation. In addition, SA concentration was three times higher in root exudates from whitefly-infested plants. As a consequence, Agrobacterium-mediated transformation of roots of whitefly-infested plants was clearly inhibited when compared to control plants. These results suggest that aboveground whitefly infestation elicits systemic defence responses throughout the plant. Our findings provide new insights into insect-mediated leaf-root intra-communication and a framework to understand interactions between three organisms: whitefly, N. benthamiana and Agrobacterium. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  16. Installation, care, and maintenance of wood shake and shingle roofs

    Science.gov (United States)

    Tony Bonura; Jack Dwyer; Arnie Nebelsick; Brent Stuart; R. Sam Williams; Christopher Hunt

    2011-01-01

    This article gives general guidelines for selection, installation, finishing, and maintenance of wood shake and shingle roofs. The authors have gathered information from a variety of sources: research publications on wood finishing, technical data sheets from paint manufacturers, installation instructions for shake and shingle roofs, and interviews with experts having...

  17. Comparative properties of ceramic-based roofing sheets from local ...

    African Journals Online (AJOL)

    Ceramic roofing sheets were fabricated in the laboratory by using ideal raw materials. The fabricating materials are coiled coconut fibre, palm fruit fibre, fresh water, river sand, polymeric dust, saw dust and cement. The resulting product was compared with factory -produced ceramic-based roofing sheets that are easily ...

  18. Fourier analysis of conductive heat transfer for glazed roofing materials

    Energy Technology Data Exchange (ETDEWEB)

    Roslan, Nurhana Lyana; Bahaman, Nurfaradila; Almanan, Raja Noorliyana Raja; Ismail, Razidah [Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Zakaria, Nor Zaini [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2014-07-10

    For low-rise buildings, roof is the most exposed surface to solar radiation. The main mode of heat transfer from outdoor via the roof is conduction. The rate of heat transfer and the thermal impact is dependent on the thermophysical properties of roofing materials. Thus, it is important to analyze the heat distribution for the various types of roofing materials. The objectives of this paper are to obtain the Fourier series for the conductive heat transfer for two types of glazed roofing materials, namely polycarbonate and polyfilled, and also to determine the relationship between the ambient temperature and the conductive heat transfer for these materials. Ambient and surface temperature data were collected from an empirical field investigation in the campus of Universiti Teknologi MARA Shah Alam. The roofing materials were installed on free-standing structures in natural ventilation. Since the temperature data are generally periodic, Fourier series and numerical harmonic analysis are applied. Based on the 24-point harmonic analysis, the eleventh order harmonics is found to generate an adequate Fourier series expansion for both glazed roofing materials. In addition, there exists a linear relationship between the ambient temperature and the conductive heat transfer for both glazed roofing materials. Based on the gradient of the graphs, lower heat transfer is indicated through polyfilled. Thus polyfilled would have a lower thermal impact compared to polycarbonate.

  19. Thermal analysis of building roof assisted with water heater and ...

    Indian Academy of Sciences (India)

    D Prakash

    2018-03-14

    Mar 14, 2018 ... Thermal analysis; building roof; solar water heating system; roof ... These solar collec- ... several benefits, such as its wide range of storage temper- ... rugated plate, rear plate and back insulation material [12]. ..... [7] Weiss W and Rommel M 2008 Process heat collectors. State of the art within Task 33/IV.

  20. Extensive Green Roof Research Program at Colorado State University

    Science.gov (United States)

    In the high elevation, semi-arid climate of Colorado, green roofs have not been scientifically tested. This research examined alternative plant species, media blends, and plant interactions on an existing modular extensive green roof in Denver, Colorado. Six plant species were ev...

  1. Single-Sided Natural Ventilation through a Velux Roof Window

    DEFF Research Database (Denmark)

    Li, Zhigang; Nielsen, Peter Vilhelm; Fransson, J.

    2004-01-01

    This paper investigates the single-sided natural ventilation through a VELUX centre pivot roof window under natural weather conditions. The aim of the investigation is to develop an empirical formulation for air flow rate through a roof window based on CFD and tracer gas decay measurement methods...

  2. U-value measurements on a roof window

    DEFF Research Database (Denmark)

    Duer, Karsten

    1998-01-01

    This report describes the results of the U-value measurements performed on a roof window. The work is as a part of the development of an ISO/CEN standard measuring procedure for roof windows.The measurements have been performed using the procedures given in ISO 12567 draft version 1998...

  3. New typologies for active roofs; An integral approach

    NARCIS (Netherlands)

    Zeiler, W.; Quanjel, E.M.C.J.; Borsboom, W.; Spoorenberg, H.

    2006-01-01

    A wide variety of new products, such as photovoltaic (PV) systems and solar collectors, roof lights, ventilation devices, insulation and safety devices, is finding its way into the roofing industry. As a result many problems occurred, resulting in poor quality, unsafe working conditions and high

  4. New typologies for active roofs; an integral approach

    NARCIS (Netherlands)

    Quanjel, E.M.C.J.; Borsboom, W.A.; Spoorenberg, H.H.R.

    2006-01-01

    A wide variety of new products, such as photovoltaic (PV) systems and solar collectors, roof lights, ventilation devices, insulation and safety devices, is finding its way into the roofing industry. As a result many problems occurred, resulting in poor quality, unsafe working conditions and high

  5. Cool metal roofing tested for energy efficiency and sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Miller, W.A.; Desjarlais, A. [Oak Ridge National Laboratory, Oakridge, TN (United States); Parker, D.S. [Florida Solar Energy Center, Cocoa, FL (United States); Kriner, S. [Metal Construction Association, Glenview, IL (United States)

    2004-07-01

    A 3 year field study was conducted in which temperature, heat flow, reflectance and emittance field data were calculated for 12 different painted and unpainted metal roofs exposed to weathering at an outdoor test facility at Oak Ridge National Laboratory in Oakridge, Tennessee. In addition, the Florida Solar Energy Center tested several Habitat for Humanity homes during one summer in Fort Myers, Florida. The objective was to determine how cooling and heating energy loads in a building are affected by the solar reflectance and infrared emittance of metal roofs. The Habitat for Humanities houses had different roofing systems which reduced the attic heat gain. White reflective roofs were shown to reduce cooling energy needs by 18 to 26 per cent and peak demand by 28 to 35 per cent. High solar reflectance and high infrared emittance roofs incur surface temperatures that are about 3 degrees C warmer than the ambient air temperature. A dark absorptive roof exceeds the ambient air temperature by more than 40 degrees C. It hot climates, a high solar reflectance and high infrared emittance roof can reduce the air conditioning load and reduce peak energy demands on the utility. It was concluded that an informed decision of the roof surface properties of reflectance and emittance can significantly reduce energy costs for homeowners and builders in hot climates. 7 refs., 2 tabs., 7 figs.

  6. Calculation of parameters of combined frame and roof bolting

    Science.gov (United States)

    Ivanov, S. I.; Titov, N. V.; Privalov, A. A.; Trunov, I. T.; Sarychev, V. I.

    2017-10-01

    The paper presents the method of calculation of the combined frame and roof bolting. Recommendations on providing joint operation of roof bolting with steel support frames are given. Graphs for determining standard rock movement, as well as for defining proof load on the yielding support, were developed.

  7. ULC/ORD-C80.1 : the standard for aboveground non-metallic tanks for fuel oil

    Energy Technology Data Exchange (ETDEWEB)

    Nikolic, G. [Underwriters' Lab. of Canada, Toronto, ON (Canada)

    2001-09-01

    As a rule, flammable and combustible liquids were stored in aboveground tanks made of steel. Non-metallic materials are now being used for a new generation of aboveground tanks. Corrosion is a problem faced by most tank owners in many parts of Canada. Saltwater mist, sand blasting and bacteria growth formed in the condensation water at the bottom of the tank in the Maritimes affects an aboveground tank installed outdoors and close to the seashore. European non-metallic aboveground tanks for fuel oil first arrived on the North American market, and are now followed by designs from Canada. Requirements for these tanks were developed and tested by the Underwriters' Laboratories of Canada (ULC). It is a not-for-profit, independent organization accredited by the Standards Council of Canada to perform safety, certification, testing, quality registration, and standards development. The minimum criteria for non-metallic aboveground tank construction are contained in the ULC/ORD-C80.1 document. They can be constructed of fiber-reinforced plastic (FRP), single or double wall, or they can be double wall tanks consisting of primary plastic tanks within metallic secondary containment. Other tanks are made of the blow molded high-density polyethylene. To simulate an in-house installation, fire tests were performed where a tank filled with fuel was exposed to pool fire for 30 minutes. A successful test meant the tank had not ruptured nor leaked during and after the test. Testers had to observe that any collapse occurred above the liquid level, and that violent explosion of any part of the tank or its content did not occur. The design requirements were evaluated by performing an analysis of the temperature chart: maximum vapour temperature inside the tank was 358 Celsius, while the liquid reached a maximum temperature of 91 Celsius and the outside temperature reached 600 Celsius. Primary tank pressure did not exceed 17 kilo Pascal. Building simulation of venting installation

  8. Development of test method for evaluating root resistance of pavement used for roof garden caused by thickening growth of root

    Energy Technology Data Exchange (ETDEWEB)

    Ishihara, Saori; Tanaka, Kyoji [Tokyo Institute of Technology, Tokyo, (Japan)

    2010-07-01

    The growth of roots of plants can damage roof garden components, such as pavements. This paper developed a test method for evaluating the resistance of pavement used in roof gardens to damage from a thickening growth of roots. The study assessed the behaviour of plant roots and evaluated the force of root growth subjected to hypertrophy. A system to measure the enlargement force of roots was designed and used for measurements over a period of 8 months on a cherry blossom of 21 years growth. The enlargement force was approximately 440 N/cm. A mechanical simulated root was designed and used to carry out experimental tests on asphalt pavements. The tests results demonstrated the viability of simulated root for evaluation of root resistances in pavements and various components of roof gardens.

  9. Greenbacks from green roofs: forging a new industry in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Peck, S. W.; Callaghan, C. [Peck and Associates, Toronto, ON (Canada); Bass, B. [Environment Canada, Toronto, ON (Canada); Kuhn, M. [Toronto, ON (Canada)

    1999-03-01

    This report provides a comprehensive review of the qualitative and quantitative benefits of green roof and vertical garden technologies, explains the nature of roof greening and green roof systems, examines the barriers to their more rapid diffusion into Canadian markets, and makes recommendations as to how how these barriers may be overcome. Two basic types of green roof systems, extensive and intensive, are identified. Extensive green roofs are characterized by their low weight, low capital cost and low maintenance. Intensive green roofs, by contrast, are heavier, more costly to establish, require intensive planting and higher maintenance. Both types of green roofs may be further subdivided into accessible or inaccessible. Accessible green roofs are flat, outdoor open spaces intended for use as gardens or terraces, while inaccessible roofs are only accessible for periodic maintenance. 'Vertical gardens' are a type of extensive green roof, characterized by the growing of plants on or up against the facade of buildings. The many benefits of green roof or vertical garden technologies include energy cost savings due to increased insulation and improved protection of the roof membrane, air quality improvements, new employment opportunities for a wide range of people including suppliers of roof membranes and related products, and social benefits such as improved aesthetics, health and horticultural therapy. Barriers to diffusion in Canada have been identified as lack of awareness, lack of incentives to implement, cost implications, lack of technical standards, few existing examples and risks associated with uncertainty. The recommendations to overcome market barriers are intended to address these barriers, i.e. they call for increased efforts to generate awareness through addressing the knowledge availability issue, and through high profile demonstration projects, government-sponsored technology diffusion, financial incentives to overcome cost-based barriers

  10. Green roof and storm water management policies: monitoring experiments on the ENPC Blue Green Wave

    Science.gov (United States)

    Versini, Pierre-Antoine; Gires, Auguste; Fitton, George; Tchiguirinskaia, Ioulia; Schertzer, Daniel

    2015-04-01

    Currently widespread in new urban projects, green roofs have shown a positive impact on urban runoff at the building/parcel scale. Nevertheless, there is no specific policy promoting their implementation neither in Europe nor in France. Moreover they are not taken into account (and usually considered as an impervious area) in the sizing of a retention basin for instance. An interesting example is located in the heart of the Paris-East Cluster for Science and Technology (Champs-sur-Marne, France). Since 2013 a large (1 ha) wavy-form vegetated roof (called bleu green wave) is implemented. Green roof area and impervious areas are connected to a large retention basin, which has been oversized. The blue green wave represents a pioneering site where an initially amenity (decorative) design project has been transformed into a research oriented one. Several measurement campaigns have been conducted to investigate and better understand the hydrological behaviour of such a structure. Rainfall, humidity, wind velocity, water content and temperature have been particularly studied. The data collected are used for several purposes: (i) characterize the spatio-temporal variability of the green roof response, (ii) calibrate and validate a specific model simulating its hydrological behavior. Based on monitoring and modeling results, green roof performances will be quantified. It will be possible to estimate how they can reduce stormwater runoff and how these performances can vary in space and in time depending on green roof configuration, rainfall event characteristics and antecedent conditions. These quantified impacts will be related to regulation rules established by stormwater managers in order to connect the parcel to the sewer network. In the particular case of the building of a retention basin, the integration of green roof in the sizing of the basin will be studied. This work is funded by the European Blue Green Dream project (http://bgd.org.uk/, funded by Climate

  11. Experimental analysis of green roof substrate detention characteristics.

    Science.gov (United States)

    Yio, Marcus H N; Stovin, Virginia; Werdin, Jörg; Vesuviano, Gianni

    2013-01-01

    Green roofs may make an important contribution to urban stormwater management. Rainfall-runoff models are required to evaluate green roof responses to specific rainfall inputs. The roof's hydrological response is a function of its configuration, with the substrate - or growing media - providing both retention and detention of rainfall. The objective of the research described here is to quantify the detention effects due to green roof substrates, and to propose a suitable hydrological modelling approach. Laboratory results from experimental detention tests on green roof substrates are presented. It is shown that detention increases with substrate depth and as a result of increasing substrate organic content. Model structures based on reservoir routing are evaluated, and it is found that a one-parameter reservoir routing model coupled with a parameter that describes the delay to start of runoff best fits the observed data. Preliminary findings support the hypothesis that the reservoir routing parameter values can be defined from the substrate's physical characteristics.

  12. Software for roof defects recognition on aerial photographs

    Science.gov (United States)

    Yudin, D.; Naumov, A.; Dolzhenko, A.; Patrakova, E.

    2018-05-01

    The article presents information on software for roof defects recognition on aerial photographs, made with air drones. An areal image segmentation mechanism is described. It allows detecting roof defects – unsmoothness that causes water stagnation after rain. It is shown that HSV-transformation approach allows quick detection of stagnation areas, their size and perimeters, but is sensitive to shadows and changes of the roofing-types. Deep Fully Convolutional Network software solution eliminates this drawback. The tested data set consists of the roofing photos with defects and binary masks for them. FCN approach gave acceptable results of image segmentation in Dice metric average value. This software can be used in inspection automation of roof conditions in the production sector and housing and utilities infrastructure.

  13. Reflective ‘cool’ roofs under aerosol-burdened skies: radiative benefits across selected Indian cities

    International Nuclear Information System (INIS)

    Millstein, D E; Fischer, M L

    2014-01-01

    The use of reflective surfaces offers one low-cost solution for reducing solar loading to urban environments and the Earth that should be considered as part of sustainable urban design. Here, we characterize the radiative benefits, i.e. the additional shortwave radiation leaving the atmosphere, from the installation of highly reflective ‘cool’ roofs in urban areas in India that face relatively large local aerosol burdens. We use a previously tested column radiative transfer model to estimate the energy per unit area reflected to space from increasing the surface albedo at six cities within India. The model is used to characterize radiative transfer each day over five years (2008–2012) based on mid-day satellite retrievals of MODIS aerosol depth, cloud water path, and average surface albedo and MERRA atmospheric profiles of temperature and composition. Compared against ten months of field observations in two cities, the model derived incoming surface shortwave radiation estimates relative to observations show small biases (0.5% and −2.6%, at Pantnagar and Nainital, respectively). Despite the high levels of local aerosols we found cool roofs provided significant radiative benefits at all locations. Averaged over the five year period we found that increasing the albedo of 1 m 2 of roof area by 0.5 would reflect to space 0.9–1.2 kWh daily from 08:30–15:30 LST, depending on location. This is equivalent to a constant forcing of 37–50 W m −2 (equivalent to reducing CO 2 emissions by 74 to 101 kg CO 2 m −2 roof area). Last, we identify a co-benefit of improving air quality, in that removing aerosols from the atmosphere could increase the radiative benefits from cool roofs by 23–74%, with the largest potential increase found at Delhi and the smallest change found at Nainital. (letter)

  14. Use of LiDAR for calculating solar irradiance on roofs and façades of buildings at city scale: Methodology, validation, and analysis

    Science.gov (United States)

    Cheng, Liang; Xu, Hao; Li, Shuyi; Chen, Yanming; Zhang, Fangli; Li, Manchun

    2018-04-01

    As the rate of urbanization continues to accelerate, the utilization of solar energy in buildings plays an increasingly important role in sustainable urban development. For this purpose, we propose a LiDAR-based joint approach for calculating the solar irradiance incident on roofs and façades of buildings at city scale, which includes a methodology for calculating solar irradiance, the validation of the proposed method, and analysis of its application. The calculation of surface irradiance on buildings may then inform photovoltaic power generation simulations, architectural design, and urban energy planning. Application analyses of the proposed method in the experiment area found that: (1) Global and direct irradiations vary significantly by hour, day, month and season, both following the same trends; however, diffuse irradiance essentially remains unchanged over time. (2) Roof irradiation, but not façade irradiation, displays distinct time-dependent patterns. (3) Global and direct irradiations on roofs are highly correlated with roof aspect and slope, with high global and direct irradiations observed on roofs of aspect 100-250° and slopes of 0-60°, whereas diffuse irradiation on roofs is only affected by roof slope. (4) The façade of a building receives higher levels of global and direct irradiations if facing southeast, south, and southwest; however, diffuse irradiation remains constant regardless of façade orientation.

  15. QUANTIFYING FOREST ABOVEGROUND CARBON POOLS AND FLUXES USING MULTI-TEMPORAL LIDAR A report on field monitoring, remote sensing MMV, GIS integration, and modeling results for forestry field validation test to quantify aboveground tree biomass and carbon

    Energy Technology Data Exchange (ETDEWEB)

    Lee Spangler; Lee A. Vierling; Eva K. Stand; Andrew T. Hudak; Jan U.H. Eitel; Sebastian Martinuzzi

    2012-04-01

    Sound policy recommendations relating to the role of forest management in mitigating atmospheric carbon dioxide (CO{sub 2}) depend upon establishing accurate methodologies for quantifying forest carbon pools for large tracts of land that can be dynamically updated over time. Light Detection and Ranging (LiDAR) remote sensing is a promising technology for achieving accurate estimates of aboveground biomass and thereby carbon pools; however, not much is known about the accuracy of estimating biomass change and carbon flux from repeat LiDAR acquisitions containing different data sampling characteristics. In this study, discrete return airborne LiDAR data was collected in 2003 and 2009 across {approx}20,000 hectares (ha) of an actively managed, mixed conifer forest landscape in northern Idaho, USA. Forest inventory plots, established via a random stratified sampling design, were established and sampled in 2003 and 2009. The Random Forest machine learning algorithm was used to establish statistical relationships between inventory data and forest structural metrics derived from the LiDAR acquisitions. Aboveground biomass maps were created for the study area based on statistical relationships developed at the plot level. Over this 6-year period, we found that the mean increase in biomass due to forest growth across the non-harvested portions of the study area was 4.8 metric ton/hectare (Mg/ha). In these non-harvested areas, we found a significant difference in biomass increase among forest successional stages, with a higher biomass increase in mature and old forest compared to stand initiation and young forest. Approximately 20% of the landscape had been disturbed by harvest activities during the six-year time period, representing a biomass loss of >70 Mg/ha in these areas. During the study period, these harvest activities outweighed growth at the landscape scale, resulting in an overall loss in aboveground carbon at this site. The 30-fold increase in sampling density

  16. Mobilization and distribution of lead originating from roof dust and wet deposition in a roof runoff system.

    Science.gov (United States)

    Yu, Jianghua; Yu, Haixia; Huang, Xiaogu

    2015-12-01

    In this research, the mobilization and distribution of lead originating in roof dust and wet deposition were investigated within a roof dust-rooftop-runoff system. The results indicated that lead from roof dust and wet deposition showed different transport dynamics in runoff system and that this process was significantly influenced by the rainfall intensity. Lead present in the roof dust could be easily washed off into the runoff, and nearly 60 % of the total lead content was present in particulate form. Most of the lead from the roof dust was transported during the late period of rainfall; however, the lead concentration was higher for several minutes at the rainfall beginning. Even though some of the lead from wet deposition, simulated with a standard isotope substance, was adsorbed onto adhered roof dust and/or retained on rooftop in runoff system, most of it (50-82 %) remained as dissolved lead in the runoff for rainfall events of varying intensity. Regarding the distribution of lead in the runoff system, the results indicated that it could be carried in the runoff in dissolved and particulate form, be adsorbed to adhered roof dust, or remain on the rooftop because of adsorption to the roof material. Lead from the different sources showed different distribution patterns that were also related to the rainfall intensity. Higher rainfall intensity resulted in a higher proportion of lead in the runoff and a lower proportion of lead remaining on the rooftop.

  17. Entire cities could benefit from green roofs : Heleen Mees is investigating how five metropolises are greenifying their roofs

    NARCIS (Netherlands)

    Mees, Heleen

    Rotterdam is making good progress with its creation of green roofs. Heleen Mees, researcher at Utrecht University, drew this conclusion from her research, in which she compared the green roof policy of four different cities with that of Rotterdam. Rotterdam awards grants to those wishing to create a

  18. An innovative roofing system for tropical building interiors: Separating heat from useful visible light

    Energy Technology Data Exchange (ETDEWEB)

    Al-Obaidi, K.M.; Ismail, M.; Abdul Rahman, A.M. [School of Housing, Building and Planning, Universiti Sains Malaysia, 11800, Minden, Pulau Pinang (Malaysia)

    2013-07-01

    Generally it has been known that energy consumption costs are high in temperate countries. In buildings, room spaces are normally designed so as to consume less energy for thermal comfort especially in winter. Passive strategies such large double-glazing windows are to contain heat indoors and also for maximum daylight to reduce dependence on artificial lighting. Thus roof lights are popular building design elements in cold and temperate countries. Unlike in the tropics where it has high temperatures and humidity throughout the year, achieving indoor comfort is a challenge especially with plenty of sunshine and unpredictable wind conditions. This paper explores the possibility of roof light for indoor comfort to be considered as a tropical design element. Initial simulation was carried out before any attempt to do life-sized model for empirical data. By simulation, the hypothesis has been achieved but several factors have to be considered. The solution is not as simple as those achieved in the temperate countries. Comfort can be achieved but permutations of several design factors such as dimensions of room, glazing, reflective materials, blackbody concept and building materials need adjustment to meet the Malaysian Comfort Temperature. With this finding the Tropical Architecture would then be redefined with the introduction of this Innovative Roofing System (IRS) as named by the author.

  19. Results for the Aboveground Configuration of the Boiling Water Reactor Dry Cask Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Durbin, Samuel G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Nuclear Fuel Cycle Technologies; Lindgren, Eric Richard [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Nuclear Fuel Cycle Technologies

    2016-09-01

    The thermal performance of commercial nuclear spent fuel dry storage casks are evaluated through detailed numerical analysis. These modeling efforts are completed by the vendor to demonstrate performance and regulatory compliance. The calculations are then independently verified by the Nuclear Regulatory Commission (NRC). Carefully measured data sets generated from testing of full sized casks or smaller cask analogs are widely recognized as vital for validating these models. Recent advances in dry storage cask designs have significantly increased the maximum thermal load allowed in a cask in part by increasing the efficiency of internal conduction pathways and also by increasing the internal convection through greater canister helium pressure. These same canistered cask systems rely on ventilation between the canister and the overpack to convect heat away from the canister to the environment for both above and belowground configurations. While several testing programs have been previously conducted, these earlier validation attempts did not capture the effects of elevated helium pressures or accurately portray the external convection of aboveground and belowground canistered dry cask systems. The purpose of the current investigation was to produce data sets that can be used to test the validity of the assumptions associated with the calculations used to determine steady-state cladding temperatures in modern dry casks that utilize elevated helium pressure in the sealed canister in an aboveground configuration. An existing electrically heated but otherwise prototypic BWR Incoloy-clad test assembly was deployed inside of a representative storage basket and cylindrical pressure vessel that represents a vertical canister system. The symmetric single assembly geometry with well-controlled boundary conditions simplifies interpretation of results. The arrangement of ducting was used to mimic conditions for an aboveground storage configuration in a vertical, dry cask

  20. EVALUATION OF ROOF BOLTING REQUIREMENTS BASED ON IN-MINE ROOF BOLTER DRILLING

    Energy Technology Data Exchange (ETDEWEB)

    Syd S. Peng

    2005-04-15

    In this quarter, the field, theoretical and programming works have been performed toward achieving the research goals set in the proposal. The main accomplishments in this quarter included: (1) one more field test has been conducted in an underground coal mine, (2) optimization studies of the control parameters have been conducted, (3) the relationship among feed pressure, penetration rate and rotation rate seems to be a good indicator for estimating rock strength when both penetration rate and rotation rate are controlled or kept constant, (4) the empirical equations for eliminating the machine effect on drilling parameters were developed and verified, and (5) a real time roof geology mapping system for roof bolters in limestone mine, including a special version of the geology mapping program and hardware, performs very well in underground production condition.

  1. ALLOMETRIC EQUATIONS FOR ESTIMATING ABOVEGROUND BIOMASS IN PAPUA TROPICAL FOREST

    Directory of Open Access Journals (Sweden)

    Sandhi Imam Maulana

    2014-10-01

    Full Text Available Allometric equations can be used to estimate biomass and carbon stock of  the forest. However, so far the allometric equations for commercial species in Papua tropical forests have not been appropriately developed. In this research, allometric equations are presented based on the genera of  commercial species. Few equations have been developed for the commercial species of  Intsia, Pometia, Palaquium and Vatica genera and an equation of  a mix of  these genera. The number of  trees sampled in this research was 49, with diameters (1.30 m above-ground or above buttresses ranging from 5 to 40 cm. Destructive sampling was used to collect the samples where Diameter at Breast Height (DBH and Wood Density (WD were used as predictors for dry weight of  Total Above-Ground Biomass (TAGB. Model comparison and selection were based on the values of  F-statistics, R-sq, R-sq (adj, and average deviation. Based on these statistical indicators, the most suitable model for Intsia, Pometia, Palaquium and Vatica genera respectively are Log(TAGB = -0.76 + 2.51Log(DBH, Log(TAGB = -0.84 + 2.57Log(DBH, Log(TAGB = -1.52 + 2.96Log(DBH, and Log(TAGB = -0.09 + 2.08Log(DBH. Additional explanatory variables such as Commercial Bole Height (CBH do not really increase the indicators’ goodness of  fit for the equation. An alternative model to incorporate wood density should  be considered for estimating the above-ground biomass for mixed genera. Comparing the presented mixed-genera equation; Log(TAGB = 0.205 + 2.08Log(DBH + 1.75Log(WD, R-sq: 97.0%, R-sq (adj: 96.9%, F statistics 750.67, average deviation: 3.5%; to previously published datashows that this local species specific equation differs substantially from previously published equations and this site-specific equation is  considered to give a better estimation of  biomass.

  2. Cool roofs and the influence on the energy consumption under Danish conditions

    DEFF Research Database (Denmark)

    Brandt, Erik; Bunch-Nielsen, Tommy; Juhl, Lasse

    Experience from countries in warm climates has shown that the color of the roofing material has a significant effect on the energy consumption of the building. Especially changing from black to white roofing material provides reduction in energy consumption. The investigated roofs have been...... with a moderate amount of thermal insulation. The Danish Roofing Advisory Board in Denmark has conducted an analysis of the effects of roofing color on buildings energy consumption under Danish conditions i.e. with a colder climate and with a larger amount of thermal insulation. An experiment was performed...... in order to study the effects of the roofing color on the temperature distribution in a roof structure. The studied roof specimens were flat roofs covered with roofing felt in different colors. Temperatures have been measured in the roofing felt as well as in the middle and the bottom of the structure...

  3. Aboveground persistence of vascular plants in relationship to the levels of airborne nutrient deposition

    NARCIS (Netherlands)

    Hendriks, R.J.J.; Ozinga, W.A.; Berg, van den L.J.L.; Noordwijk, E.; Schaminee, J.H.J.; Groenendael, van J.M.

    2014-01-01

    This paper examines whether high atmospheric nitrogen deposition affects aboveground persistence of vascular plants. We combined information on local aboveground persistence of vascular plants in 245 permanent plots in the Netherlands with estimated level of nitrogen deposition at the time of

  4. Analysis of technical-economic requirements for the construction of a solar power plant on the roof of the business building of the Electrical Engineering Institute 'Nikola Tesla'

    OpenAIRE

    Grbić, Maja; Antić, Radoslav; Ponoćko, Jelena; Mikulović, Jovan; Đurišić, Željko

    2014-01-01

    This paper presents an analysis of the technical-economic requirements for the construction of a solar power plant on the roof of the business building of the Electrical Engineering Institute 'Nikola Tesla' in Belgrade. Calculation of solar irradiation is performed and the conceptual design of the disposition of solar panels on the roof of the building is shown as well as their connections to the inverters. Conditions for connecting the plant to the distribution network are checked and an eco...

  5. Stormwater quality from extensive green roofs in a subtropical region

    Science.gov (United States)

    Onis Pessoa, Jonas; Allasia, Daniel; Tassi, Rutineia; Vaz Viega, Juliana; Fensterseifer, Paula

    2016-04-01

    Green roofs have increasingly become an integral part of urban environments, mainly due to their aesthetic benefits, thermal comfort and efficiency in controlling excess runoff. However, the effects of this emerging technology in the qualitative characteristics of rainwater is still poorly understood. In this study was evaluated the effect of two different extensive green roofs (EGRs) and a traditional roof built with corrugated fiber cement sheets (control roof) in the quality of rainwater, in a subtropical climate area in the city of Santa Maria, in southern Brazil. The principal variant between the two EGRs were the type of plant species, time since construction, soil depth and the substrate characteristics. During the monitoring period of the experiment, between the months of April and December of 2015 fourteen rainfall events were selected for qualitative analysis of water from the three roofs and directly from rainfall. It was analyzed physical (turbidity, apparent color, true color, electrical conductivity, total solids, dissolved solids, suspended solids and temperature), chemical (pH, phosphate, total nitrogen, nitrate, nitrite, chloride, sulfate, BOD, iron and total hardness), heavy metals (copper, zinc, lead and chromium) and microbiological parameters (total coliforms and E. coli). It was also characterized the substrates used in both extensive green roofs. The results showed that the quality of the water drained from EGR s was directly influenced by their substrates (in turn containing significant levels of nutrients, organic matter and some metals). The passage of rainwater through green roofs and control roof resulted in the elevation of pH, allowing the conversion of the slightly acidic rainfall into basic water. Similarly, on both types of roofs occurred an increase of the values of most of the physical, chemical and microbiological parameters compared to rainwater. This same trend was observed for heavy metals, although with a much smaller degree

  6. Numerical analysis on thermal performance of roof contained PCM of a single residential building

    International Nuclear Information System (INIS)

    Li, Dong; Zheng, Yumeng; Liu, Changyu; Wu, Guozhong

    2015-01-01

    Highlights: • Thermal performance of different roofs in cold area of China are investigated. • Effects of five different conditions on thermal performance of roofs are analyzed. • Delay time of temperatures peak in PCM roofs are beyond 3 h than common roof. - Abstract: The phase change material (PCM) applied in the roof can decrease the building energy consumption and improve the thermal comfort by enhancing the thermal energy storage capacity of building envelope. In the present work, the thermal performance of different kinds of roofs with and without PCM in Northeast and cold area of China, i.e. common roof and PCM roofs, have been investigated numerically. This study also explored the influencing factors of thermal behavior of the roofs, such as solar radiation intensity, transition temperature and latent heat of PCM, roof slope, PCM layer thickness, and absorption coefficients of external roof surface. The results show that the PCM roofs effect on the temperature delay in the room is very strong and the delay time of temperatures peak of base layer in PCM roofs are beyond 3 h than common roof. The effect of transition temperature and latent heat of PCM on the thermal performance of roofs is relatively weak, compared with the roof slope, PCM layer thickness and absorption coefficients of external roof surface

  7. Drought-avoiding plants with low water use can achieve high rainfall retention without jeopardising survival on green roofs.

    Science.gov (United States)

    Szota, Christopher; Farrell, Claire; Williams, Nicholas S G; Arndt, Stefan K; Fletcher, Tim D

    2017-12-15

    Green roofs are increasingly being used among the suite of tools designed to reduce the volume of surface water runoff generated by cities. Plants provide the primary mechanism for restoring the rainfall retention capacity of green roofs, but selecting plants with high water use is likely to increase drought stress. Using empirically-derived plant physiological parameters, we used a water balance model to assess the trade-off between rainfall retention and plant drought stress under a 30-year climate scenario. We compared high and low water users with either drought avoidance or drought tolerance strategies. Green roofs with low water-using, drought-avoiding species achieved high rainfall retention (66-81%) without experiencing significant drought stress. Roofs planted with other strategies showed high retention (72-90%), but they also experienced >50days of drought stress per year. However, not all species with the same strategy behaved similarly, therefore selecting plants based on water use and drought strategy alone does not guarantee survival in shallow substrates where drought stress can develop quickly. Despite this, it is more likely that green roofs will achieve high rainfall retention with minimal supplementary irrigation if planted with low water users with drought avoidance strategies. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Can green roofs reduce urban heat stress in vulnerable urban communities: A coupled atmospheric and social modeling approach

    Science.gov (United States)

    Sharma, A.; Woodruff, S.; Budhathoki, M.; Hamlet, A. F.; Fernando, H. J. S.; Chen, F.

    2017-12-01

    Urban areas provide organized, engineered, sociological and economical infrastructure designed to provide a high quality of life, but the implementation and management of urban infrastructure has been a continued challenge. Increasing urbanization, warming climate, as well as anthropogenic heat emissions that accompany urban development generates "stress". This rapidly increasing `urban stress' affects the sustainability of cities, making populations more vulnerable to extreme hazards, such as heat. Cities are beginning to extensively use green roofs as a potential urban heat mitigation strategy. This study explores the potential of green roofs to reduce summertime temperatures in the most vulnerable neighborhoods of the Chicago metropolitan area by combining social vulnerability indices (a function of exposure, sensitivity and adaptive capacity), and temperatures from mesoscale model. Numerical simulations using urbanized version the Advanced Research Weather Research and Forecasting (WRF) model were performed to measure rooftop temperatures, a representative variable for exposure in this study. The WRF simulations were dynamically coupled with a green roof algorithm as a part of urban parameterization within WRF. Specifically, the study examines roof surface temperature with changing green roof fractions and how would they help reduce exposure to heat stress for vulnerable urban communities. This study shows an example of applied research that can directly benefit urban communities and be used by urban planners to evaluate mitigation strategies.

  9. Electron beam-curing coating for pressed cement roof tiles with high-build and excellent durability

    International Nuclear Information System (INIS)

    Maruyama, Tsutomu; Kiyata, Hiroaki

    1979-01-01

    Thick slate has expanded the demand steadily and spread to whole Japan except the northernmost part as a roof material, because it deals with rain water well, its strength, coldness resistance and endurance are excellent, and it can be worked easily. The ornamental finishing by urethane coating is not satisfactory in view of the improvement of productivity and the measures to pollution as well as the design and color. In order to meet this background, new coating has been sought, and electron beam-curing coating seems to be most suitable to cement roof tiles. The history and the present state of cement roof tiles are explained. About 700 tons/month of the coating for cement roof tiles is used at present, and acryl resin coating occupies about 75%, while urethane resin coating is used in Kyushu relatively more. The urethane coating is applied in shops by electrostatic coating, but the acryl coating is mostly applied in sites after tiling over. Electron beam curing used electron beam of 200 keV, and polymerization starts from the radicals formed through ionization, excitation and neutralization. The features of electron beam-curing coating are good adhesion to roof tiles, keeping luster and endurance to discoloration, strong film and feeling like porcelain, drying at normal temperature, productivity and economy. (J.P.N.)

  10. Rate of driving a ventilation tunnel by means of the GPK heading machine using roof bolting and steel supports. [USSR

    Energy Technology Data Exchange (ETDEWEB)

    Cheremnov, V.I.; Kruglyak, A.S.; Miroshnikova, L.A.; Sharov, V.N.

    1983-05-01

    The paper discusses a method for strata control during mine drivage tested in the im. Voroshilov coal mine in 1982. A ventilation tunnel with a crosscut of 16.4 m/sup 2/ was driven in coal with compression strength coefficient from 0.8 to 1.0, argillites and aleurites in the floor and the roof with compression strength coefficient from 4 to 6. Mining depth was 150 m, water influx was low. The tunnel was driven by means of the GPK heading machine with a 1PNB-2 loader. The AMK support system which consisted of arched steel supports, steel beams for joining steel arches and of roof bolts was used. Arched supports were installed each 0.8 m. The roof between the arches was supported by a system of roof bolts and junction beams. Support design is shown in a scheme. Increasing support spacing to 0.8 m (instead of 0.5 m) and roof bolting permitted drivage rate to be increased and steel consumption to be significantly reduced (by 244 kg/m). (3 refs.)

  11. CFD optimisation of a stadium roof geometry: a qualitative study to improve the wind microenvironment

    Directory of Open Access Journals (Sweden)

    Sofotasiou Polytimi

    2017-01-01

    Full Text Available The complexity of the built environment requires the adoption of coupled techniques to predict the flow phenomena and provide optimum design solutions. In this study, coupled computational fluid dynamics (CFD and response surface methodology (RSM optimisation tools are employed to investigate the parameters that determine the wind comfort in a two-dimensional stadium model, by optimising the roof geometry. The roof height, width and length are evaluated against the flow homogeneity at the spectator terraces and the playing field area, the roof flow rate and the average interior pressure. Based on non-parametric regression analysis, both symmetric and asymmetric configurations are considered for optimisation. The optimum design solutions revealed that it is achievable to provide an improved wind environment in both playing field area and spectator terraces, giving a further insight on the interrelations of the parameters involved. Considering the limitations of conducting a two-dimensional study, the obtained results may beneficially be used as a basis for the optimisation of a complex three-dimensional stadium structure and thus become an important design guide for stadium structures.

  12. Roof Moisture Surveys: Current State Of The Technology

    Science.gov (United States)

    Tobiasson, Wayne

    1983-03-01

    Moisture is the big enemy of compact roofing systems. Non-destructive nuclear, capacitance and infrared methods can all find wet insulation in such roofs but a few core samples are needed for verification. Nuclear and capacitance surveys generate quantitative results at grid points but examine only a small portion of the roof. Quantitative results are not usually provided by infrared scanners but they can rapidly examine every square inch of the roof. Being able to find wet areas when they are small is an important advantage. Prices vary with the scope of the investigation. For a particular scope, the three techniques are often cost-competitive. The limitations of each technique are related to the people involved as well as the equipment. When the right people are involved, non-destructive surveys are a very effective method for improving the long-term performance and reducing the life-cycle costs of roofing systems. Plans for the maintenance, repair or replacement of a roof should include a roof moisture survey.

  13. A field study to evaluate runoff quality from green roofs.

    Science.gov (United States)

    Vijayaraghavan, K; Joshi, U M; Balasubramanian, R

    2012-03-15

    Green (vegetated) roofs are emerging as practical strategies to improve the environmental quality of cities. However, the impact of green roofs on the storm water quality remains a topic of concern to city planners and environmental policy makers. This study investigated whether green roofs act as a source or a sink of various metals (Na, K, Ca, Mg, Al, Fe, Cu, Cd, Pb, Zn, Mn, Cr, Ni, Li and Co), inorganic anions (NO3-, NO2-, PO4(3-), SO4(2-), Cl-, F- and Br-) and cation (NH4+). A series of green roof assemblies were constructed. Four different real rain events and several artificial rain events were considered for the study. Results showed that concentrations of most of the chemical components in runoff were highest during the beginning of rain events and subsided in the subsequent rain events. Some of the important components present in the runoff include Na, K, Ca, Mg, Li, Fe, Al, Cu, NO3-, PO4(3-) and SO4(2-). However, the concentration of these chemical components in the roof runoff strongly depends on the nature of substrates used in the green roof and the volume of rain. Based on the USEPA standards for freshwater quality, we conclude that the green roof used in this study is reasonably effective except that the runoff contains significant amounts of NO3- and PO4(3-). Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Comparative life cycle assessment of standard and green roofs.

    Science.gov (United States)

    Saiz, Susana; Kennedy, Christopher; Bass, Brad; Pressnail, Kim

    2006-07-01

    Life cycle assessment (LCA) is used to evaluate the benefits, primarily from reduced energy consumption, resulting from the addition of a green roof to an eight story residential building in Madrid. Building energy use is simulated and a bottom-up LCA is conducted assuming a 50 year building life. The key property of a green roof is its low solar absorptance, which causes lower surface temperature, thereby reducing the heat flux through the roof. Savings in annual energy use are just over 1%, but summer cooling load is reduced by over 6% and reductions in peak hour cooling load in the upper floors reach 25%. By replacing the common flat roof with a green roof, environmental impacts are reduced by between 1.0 and 5.3%. Similar reductions might be achieved by using a white roof with additional insulation for winter, but more substantial reductions are achieved if common use of green roofs leads to reductions in the urban heat island.

  15. Chemical composition of water from roofs in Gdansk, Poland

    International Nuclear Information System (INIS)

    Tsakovski, Stefan; Tobiszewski, Marek; Simeonov, Vasil; Polkowska, Zaneta; Namiesnik, Jacek

    2010-01-01

    This study deals with the assessment of roof runoff waters from the region of Gdansk collected during the winter season (2007/2008). The chemical analysis includes 16 chemical variables: major ions, PAHs and PCBs measured at 3 sampling sites for 6-14 rain events. Although the data set is of limited volume the statistical data treatment using self-organizing maps (SOM) reveals the main factors controlling roof runoff water quality even for a data set with small dimension. This effort for explanation of the identified factors by the possible emission sources of the urban environment and air-particulate formation seems to be very reliable. Additionally to the roof runoff water quality factors the rain events patterns are found: 'background' group of events and groups formally named 'PAHs', 'PCBs' and 'air-borne particles' - dominated events. The SOM classification results give an opportunity to uncover the role of roof 'impact' on the runoff waters. Rain runoff water quality is described by four latent factors and the 'roof' impact is uncovered. - Identification of the urban roof runoff water quality factors and 'roof' impact by self-organizing map classification.

  16. Evaluating lidar point densities for effective estimation of aboveground biomass

    Science.gov (United States)

    Wu, Zhuoting; Dye, Dennis G.; Stoker, Jason M.; Vogel, John M.; Velasco, Miguel G.; Middleton, Barry R.

    2016-01-01

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) was recently established to provide airborne lidar data coverage on a national scale. As part of a broader research effort of the USGS to develop an effective remote sensing-based methodology for the creation of an operational biomass Essential Climate Variable (Biomass ECV) data product, we evaluated the performance of airborne lidar data at various pulse densities against Landsat 8 satellite imagery in estimating above ground biomass for forests and woodlands in a study area in east-central Arizona, U.S. High point density airborne lidar data, were randomly sampled to produce five lidar datasets with reduced densities ranging from 0.5 to 8 point(s)/m2, corresponding to the point density range of 3DEP to provide national lidar coverage over time. Lidar-derived aboveground biomass estimate errors showed an overall decreasing trend as lidar point density increased from 0.5 to 8 points/m2. Landsat 8-based aboveground biomass estimates produced errors larger than the lowest lidar point density of 0.5 point/m2, and therefore Landsat 8 observations alone were ineffective relative to airborne lidar for generating a Biomass ECV product, at least for the forest and woodland vegetation types of the Southwestern U.S. While a national Biomass ECV product with optimal accuracy could potentially be achieved with 3DEP data at 8 points/m2, our results indicate that even lower density lidar data could be sufficient to provide a national Biomass ECV product with accuracies significantly higher than that from Landsat observations alone.

  17. Rainwater runoff retention on an aged intensive green roof.

    Science.gov (United States)

    Speak, A F; Rothwell, J J; Lindley, S J; Smith, C L

    2013-09-01

    Urban areas are characterised by large proportions of impervious surfaces which increases rainwater runoff and the potential for surface water flooding. Increased precipitation is predicted under current climate change projections, which will put further pressure on urban populations and infrastructure. Roof greening can be used within flood mitigation schemes to restore the urban hydrological balance of cities. Intensive green roofs, with their deeper substrates and higher plant biomass, are able to retain greater quantities of runoff, and there is a need for more studies on this less common type of green roof which also investigate the effect of factors such as age and vegetation composition. Runoff quantities from an aged intensive green roof in Manchester, UK, were analysed for 69 rainfall events, and compared to those on an adjacent paved roof. Average retention was 65.7% on the green roof and 33.6% on the bare roof. A comprehensive soil classification revealed the substrate, a mineral soil, to be in good general condition and also high in organic matter content which can increase the water holding capacity of soils. Large variation in the retention data made the use of predictive regression models unfeasible. This variation arose from complex interactions between Antecedant Dry Weather Period (ADWP), season, monthly weather trends, and rainfall duration, quantity and peak intensity. However, significantly lower retention was seen for high rainfall events, and in autumn, which had above average rainfall. The study period only covers one unusually wet year, so a longer study may uncover relationships to factors which can be applied to intensive roofs elsewhere. Annual rainfall retention for Manchester city centre could be increased by 2.3% by a 10% increase in intensive green roof construction. The results of this study will be of particular interest to practitioners implementing greenspace adaptation in temperate and cool maritime climates. Copyright © 2013

  18. Case studies of green roof policy from Canada

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, S. [Canada Mortgage and Housing Corp., Ottawa, ON (Canada)

    2006-07-01

    In order to overcome environmental, economic, and social challenges, such as stormwater management, heat island effects, reducing energy use in buildings and increasing amenity space, green roof technology has been a key approach used in many European countries and is gaining acceptance throughout North America as knowledge of the environmental benefits and green roof technology grows. While the conditions, benefits and market forces that have driven green roof development in Europe are not identical to Canada's, lessons can be learned from their experiences. Canadian municipalities that are looking to develop and implement green roof policies and programs will need information on how to tailor policies and programs for specific climate conditions, environmental concerns and regulatory realities. In order to provide Canadian municipal decision-makers with an overview of international and local green roof policies and programs, a green roof policy infrastructure manual was recently completed for the Canada Mortgage and Housing Corporation. Decision-makers can be better informed about which policies may be best suited to meet their specific policy needs by reviewing the motivators and other factors behind existing programs around the world. The manual describes green roof policies in each of 12 different jurisdictions from Canada, the United States, Germany, Switzerland, Singapore, and Japan in terms of local green roof motivators and the steps taken along the continuum of establishing policy. This paper described the progress of some Canadian cities that are moving through six phases of establishing appropriate green roof policies and programs. The six phases were introductory and awareness; community engagement; action plan development and implementation; technical research; program and policy development and continuous improvement.

  19. The Advancement of Cool Roof Standards in China from 2010 to 2015

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Jing [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Levinson, Ronnen M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-11-01

    Since the initiation of the U.S.-China Clean Energy Research Center-Building Energy Efficiency (CERC-BEE) cool roof research collaboration between the Lawrence Berkeley National Laboratory Heat Island Group and Chinese institutions in 2010, new cool surface credits (insulation trade- offs) have been adopted in Chinese building energy efficiency standards, industry standards, and green building standards. JGJ 75-2012: Design Standard for Energy Efficiency of Residential Buildings in Hot Summer and Warm Winter Zone became the first national level standard to provide cool surface credits. GB/T 50378-2014: Assessment Standard for Green Building is the first national level green building standard that offers points for heat island mitigation. JGJ/T 359-2015: Technical Specification for Application of Architectural Reflective Thermal Insulation Coating is the first industry standard that offers cool coating credits for both public and residential buildings in all hot-summer climates (Hot Summer/Cold Winter, Hot Summer/Warm Winter). As of December 2015, eight provinces or municipalities in hot-summer regions have credited cool surfaces credits in their residential and/or public building design standards; five other provinces or municipalities in hot-summer regions recommend, but do not credit, the use of cool surfaces in their building design standards. Cool surfaces could be further advanced in China by including cool roof credits for residential and public building energy efficiency standards in all hot-summer regions; developing a standardized process for natural exposure and aged-property rating of cool roofing products; and adapting the U.S.-developed laboratory aging process for roofing materials to replicate solar reflectance changes induced by natural exposure in China.

  20. Automatic Generation of 3D Building Models with Multiple Roofs

    Institute of Scientific and Technical Information of China (English)

    Kenichi Sugihara; Yoshitugu Hayashi

    2008-01-01

    Based on building footprints (building polygons) on digital maps, we are proposing the GIS and CG integrated system that automatically generates 3D building models with multiple roofs. Most building polygons' edges meet at right angles (orthogonal polygon). The integrated system partitions orthogonal building polygons into a set of rectangles and places rectangular roofs and box-shaped building bodies on these rectangles. In order to partition an orthogonal polygon, we proposed a useful polygon expression in deciding from which vertex a dividing line is drawn. In this paper, we propose a new scheme for partitioning building polygons and show the process of creating 3D roof models.

  1. Effects of Solar Photovoltaic Panels on Roof Heat Transfer

    Science.gov (United States)

    Dominguez, A.; Klessl, J.; Samady, M.; Luvall, J. C.

    2010-01-01

    Building Heating, Ventilation and Air Conditioning (HVAC) is a major contributor to urban energy use. In single story buildings with large surface area such as warehouses most of the heat enters through the roof. A rooftop modification that has not been examined experimentally is solar photovoltaic (PV) arrays. In California alone, several GW in residential and commercial rooftop PV are approved or in the planning stages. With the PV solar conversion efficiency ranging from 5-20% and a typical installed PV solar reflectance of 16-27%, 53-79% of the solar energy heats the panel. Most of this heat is then either transferred to the atmosphere or the building underneath. Consequently solar PV has indirect effects on roof heat transfer. The effect of rooftop PV systems on the building roof and indoor energy balance as well as their economic impacts on building HVAC costs have not been investigated. Roof calculator models currently do not account for rooftop modifications such as PV arrays. In this study, we report extensive measurements of a building containing a flush mount and a tilted solar PV array as well as exposed reference roof. Exterior air and surface temperature, wind speed, and solar radiation were measured and thermal infrared (TIR) images of the interior ceiling were taken. We found that in daytime the ceiling surface temperature under the PV arrays was significantly cooler than under the exposed roof. The maximum difference of 2.5 C was observed at around 1800h, close to typical time of peak energy demand. Conversely at night, the ceiling temperature under the PV arrays was warmer, especially for the array mounted flat onto the roof. A one dimensional conductive heat flux model was used to calculate the temperature profile through the roof. The heat flux into the bottom layer was used as an estimate of the heat flux into the building. The mean daytime heat flux (1200-2000 PST) under the exposed roof in the model was 14.0 Watts per square meter larger than

  2. Can green roof act as a sink for contaminants? A methodological study to evaluate runoff quality from green roofs.

    Science.gov (United States)

    Vijayaraghavan, K; Joshi, Umid Man

    2014-11-01

    The present study examines whether green roofs act as a sink or source of contaminants based on various physico-chemical parameters (pH, conductivity and total dissolved solids) and metals (Na, K, Ca, Mg, Al, Fe, Cr, Cu, Ni, Zn, Cd and Pb). The performance of green roof substrate prepared using perlite, vermiculite, sand, crushed brick, and coco-peat, was compared with local garden soil based on improvement of runoff quality. Portulaca grandiflora was used as green roof vegetation. Four different green roof configurations, with vegetated and non-vegetated systems, were examined for several artificial rain events (un-spiked and metal-spiked). In general, the vegetated green roof assemblies generated better-quality runoff with less conductivity and total metal ion concentration compared to un-vegetated assemblies. Of the different green roof configurations examined, P. grandiflora planted on green roof substrate acted as sink for various metals and showed the potential to generate better runoff. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. An environmental cost-benefit analysis of alternative green roofing strategies

    Science.gov (United States)

    Richardson, M.; William, R. K.; Goodwell, A. E.; Le, P. V.; Kumar, P.; Stillwell, A. S.

    2016-12-01

    Green roofs and cool roofs are alternative roofing strategies that mitigate urban heat island effects and improve building energy performance. Green roofs consist of soil and vegetation layers that provide runoff reduction, thermal insulation, and potential natural habitat, but can require regular maintenance. Cool roofs involve a reflective layer that reflects more sunlight than traditional roofing materials, but require additional insulation during winter months. This study evaluates several roofing strategies in terms of energy performance, urban heat island mitigation, water consumption, and economic cost. We use MLCan, a multi-layer canopy model, to simulate irrigated and non-irrigated green roof cases with shallow and deep soil depths during the spring and early summer of 2012, a drought period in central Illinois. Due to the dry conditions studied, periodic irrigation is implemented in the model to evaluate its effect on evapotranspiration. We simulate traditional and cool roof scenarios by altering surface albedo and omitting vegetation and soil layers. We find that both green roofs and cool roofs significantly reduce surface temperature compared to the traditional roof simulation. Cool roof temperatures always remain below air temperature and, similar to traditional roofs, require low maintenance. Green roofs remain close to air temperature and also provide thermal insulation, runoff reduction, and carbon uptake, but might require irrigation during dry periods. Due to the longer lifetime of a green roof compared to cool and traditional roofs, we find that green roofs realize the highest long term cost savings under simulated conditions. However, using longer-life traditional roof materials (which have a higher upfront cost) can help decrease this price differential, making cool roofs the most affordable option due to the higher maintenance costs associated with green roofs

  4. Building Space Heating with a Solar-Assisted Heat Pump Using Roof-Integrated Solar Collectors

    Directory of Open Access Journals (Sweden)

    Zhiyong Yang

    2011-03-01

    Full Text Available A solar assisted heat pump (SAHP system was designed by using a roof-integrated solar collector as the evaporator, and then it was demonstrated to provide space heating for a villa in Tianjin, China. A building energy simulation tool was used to predict the space heating load and a three dimensional theoretical model was established to analyze the heat collection performance of the solar roof collector. A floor radiant heating unit was used to decrease the energy demand. The measurement results during the winter test period show that the system can provide a comfortable living space in winter, when the room temperature averaged 18.9 °C. The average COP of the heat pump system is 2.97 and with a maximum around 4.16.

  5. A Calculation Method for the Sloshing Impact Pressure Imposed on the Roof of a Passive Water Storage Tank of AP1000

    Directory of Open Access Journals (Sweden)

    Daogang Lu

    2016-01-01

    Full Text Available There is a large water storage tank installed at the top of containment of AP1000, which can supply the passive cooling. In the extreme condition, sloshing of the free surface in the tank may impact on the roof under long-period earthquake. For the safety assessment of structure, it is necessary to calculate the impact pressure caused by water sloshing. Since the behavior of sloshing impacted on the roof is involved into a strong nonlinear phenomenon, it is a little difficult to calculate such pressure by theoretical or numerical method currently. But it is applicable to calculate the height of sloshing in a tank without roof. In the present paper, a simplified method was proposed to calculate the impact pressure using the sloshing wave height, in which we first marked the position of the height of roof, then produced sloshing in the tank without roof and recorded the maximum wave height, and finally regarded approximately the difference between maximum wave height and roof height as the impact pressure head. We also designed an experiment to verify this method. The experimental result showed that this method overpredicted the impact pressure with a certain error of no more than 35%. By the experiment, we conclude that this method is conservative and applicable for the engineering design.

  6. Modeling aboveground biomass of Tamarix ramosissima in the Arkansas River Basin of Southeastern Colorado, USA

    Science.gov (United States)

    Evangelista, P.; Kumar, S.; Stohlgren, T.J.; Crall, A.W.; Newman, G.J.

    2007-01-01

    Predictive models of aboveground biomass of nonnative Tamarix ramosissima of various sizes were developed using destructive sampling techniques on 50 individuals and four 100-m2 plots. Each sample was measured for average height (m) of stems and canopy area (m2) prior to cutting, drying, and weighing. Five competing regression models (P < 0.05) were developed to estimate aboveground biomass of T. ramosissima using average height and/or canopy area measurements and were evaluated using Akaike's Information Criterion corrected for small sample size (AICc). Our best model (AICc = -148.69, ??AICc = 0) successfully predicted T. ramosissima aboveground biomass (R2 = 0.97) and used average height and canopy area as predictors. Our 2nd-best model, using the same predictors, was also successful in predicting aboveground biomass (R2 = 0.97, AICc = -131.71, ??AICc = 16.98). A 3rd model demonstrated high correlation between only aboveground biomass and canopy area (R2 = 0.95), while 2 additional models found high correlations between aboveground biomass and average height measurements only (R2 = 0.90 and 0.70, respectively). These models illustrate how simple field measurements, such as height and canopy area, can be used in allometric relationships to accurately predict aboveground biomass of T. ramosissima. Although a correction factor may be necessary for predictions at larger scales, the models presented will prove useful for many research and management initiatives.

  7. Modeling a Hydrologically Optimal Green Roof Media Mixture

    Science.gov (United States)

    Background/Questions/MethodsA key environmental concern in managing urban ecosystems is controlling stormwater runoff to ameliorate pollution problems and sewage overflows. Vegetated green roofs have become an important green infrastructure tool to collect, store, and gradually r...

  8. Diaphragm Effect of Steel Space Roof Systems in Hall Structures

    Directory of Open Access Journals (Sweden)

    Mehmet FENKLİ

    2015-09-01

    Full Text Available Hall structures have been used widely for different purposes. They have are reinforced concrete frames and shear wall with steel space roof systems. Earthquake response of hall structures is different from building type structures. One of the most critical nodes is diaphragm effect of steel space roof on earthquake response of hall structures. Diaphragm effect is depending on lateral stiffness capacity of steel space roof system. Lateral stiffness of steel space roof system is related to modulation geometry, support conditions, selected sections and system geometry. In current paper, three representative models which are commonly used in Turkey were taken in to account for investigation. Results of numerical tests were present comparatively

  9. MODELING OF STORM WATER RUNOFF FROM GREEN ROOFS

    Directory of Open Access Journals (Sweden)

    Ewa Burszta-Adamiak

    2014-10-01

    Full Text Available Apart from direct measurements, modelling of runoff from green roofs is valuable source of information about effectiveness of this type of structure from hydrological point of view. Among different type of models, the most frequently used are numerical models. They allow to assess the impact of green roofs on decrease and attenuation of runoff, reduction of peak runoff and value of water retention. This paper presents preliminary results of research on computing the rate of runoff from green roofs using GARDENIA model. The analysis has been carried out for selected rainfall events registered during measuring campaign on pilot-scale green roofs. Obtained results are promising and show good fit between observed and simulated runoff.

  10. Summer Thermal Performance of Ventilated Roofs with Tiled Coverings

    International Nuclear Information System (INIS)

    Bortoloni, M; Bottarelli, M; Piva, S

    2017-01-01

    The thermal performance of a ventilated pitched roof with tiled coverings is analysed and compared with unventilated roofs. The analysis is carried out by means of a finite element numerical code, by solving both the fluid and thermal problems in steady-state. A whole one-floor building with a pitched roof is schematized as a 2D computational domain including the air-permeability of tiled covering. Realistic data sets for wind, temperature and solar radiation are used to simulate summer conditions at different times of the day. The results demonstrate that the batten space in pitched roofs is an effective solution for reducing the solar heat gain in summer and thus for achieving better indoor comfort conditions. The efficiency of the ventilation is strictly linked to the external wind conditions and to buoyancy forces occurring due to the heating of the tiles. (paper)

  11. Summer Thermal Performance of Ventilated Roofs with Tiled Coverings

    Science.gov (United States)

    Bortoloni, M.; Bottarelli, M.; Piva, S.

    2017-01-01

    The thermal performance of a ventilated pitched roof with tiled coverings is analysed and compared with unventilated roofs. The analysis is carried out by means of a finite element numerical code, by solving both the fluid and thermal problems in steady-state. A whole one-floor building with a pitched roof is schematized as a 2D computational domain including the air-permeability of tiled covering. Realistic data sets for wind, temperature and solar radiation are used to simulate summer conditions at different times of the day. The results demonstrate that the batten space in pitched roofs is an effective solution for reducing the solar heat gain in summer and thus for achieving better indoor comfort conditions. The efficiency of the ventilation is strictly linked to the external wind conditions and to buoyancy forces occurring due to the heating of the tiles.

  12. Comparison of the chemical quality of rainwater harvested from roof ...

    African Journals Online (AJOL)

    2018-04-02

    Apr 2, 2018 ... 4, place Jussieu 75252 Paris Cedex 05, France ... Keywords: rainwater harvesting, roof-harvested rainwater, pollution, human health, food security, ... Received 18 December 2015; accepted in revised form 26 March 2018.

  13. Potential energy savings from cool roofs in Spain and Andalusia

    International Nuclear Information System (INIS)

    Boixo, Sergio; Diaz-Vicente, Marian; Colmenar, Antonio; Castro, Manuel Alonso

    2012-01-01

    Cool roofs are an inexpensive method to save energy and to improve the comfort level in buildings in mild and hot climates. A high scale implementation of cool roofs in Andalusia, in the south of Spain, could potentially save 295,000 kWh per year, considering only residential buildings with flat roofs using electrical heating. At the current energy prices, consumers can save 59 million euros annually in electricity costs and the emission of 136,000 metric tons of CO 2 can be directly avoided every year from the production of that electricity. If radiative forcings are considered, Andalucía can potentially offset between 9.44 and 12 Mt of CO 2 . All the provinces in the rest of Spain are also studied in this paper. The biggest savings are achieved in Gran Canaria (48%), Tenerife (48%), Cádiz (36%), Murcia (33%), Huelva (30%), Málaga (29%), Almería (29%) and Sevilla (28%), where savings are greater than 2 euros per square meter of flat roof for old buildings with dark roofs. For the biggest cities the range of savings obtained are: between 7.4% and 11% in Madrid, between 12% and 18% in Barcelona and between 14% and 20% in Valencia. -- Highlights: ► We estimate potential savings in energy, CO 2 , and money for cool roofs in Spain (residential sector with flat roofs). ► Average savings are of around one euro per square meter in the biggest cities. ► Potential savings are of more than 2 €/m 2 in the hottest cities. ► In Andalusia the potential savings are 300 MWh, 60 millions euro and 136,000 tons of CO 2 per year. ► With forcings, the CO 2 equivalence of cool roofs in Andalusia is between 9 and 12 Mt.

  14. Plant species richness enhances nitrogen retention in green roof plots.

    Science.gov (United States)

    Johnson, Catherine; Schweinhart, Shelbye; Buffam, Ishi

    2016-10-01

    Vegetated (green) roofs have become common in many cities and are projected to continue to increase in coverage, but little is known about the ecological properties of these engineered ecosystems. In this study, we tested the biodiversity-ecosystem function hypothesis using commercially available green roof trays as replicated plots with varying levels of plant species richness (0, 1, 3, or 6 common green roof species per plot, using plants with different functional characteristics). We estimated accumulated plant biomass near the peak of the first full growing season (July 2013) and measured runoff volume after nearly every rain event from September 2012 to September 2013 (33 events) and runoff fluxes of inorganic nutrients ammonium, nitrate, and phosphate from a subset of 10 events. We found that (1) total plant biomass increased with increasing species richness, (2) green roof plots were effective at reducing storm runoff, with vegetation increasing water retention more than soil-like substrate alone, but there was no significant effect of plant species identity or richness on runoff volume, (3) green roof substrate was a significant source of phosphate, regardless of presence/absence of plants, and (4) dissolved inorganic nitrogen (DIN = nitrate + ammonium) runoff fluxes were different among plant species and decreased significantly with increasing plant species richness. The variation in N retention was positively related to variation in plant biomass. Notably, the increased biomass and N retention with species richness in this engineered ecosystem are similar to patterns observed in published studies from grasslands and other well-studied ecosystems. We suggest that more diverse plantings on vegetated roofs may enhance the retention capacity for reactive nitrogen. This is of importance for the sustained health of vegetated roof ecosystems, which over time often experience nitrogen limitation, and is also relevant for water quality in receiving waters

  15. Building Integrated Photovoltaic (BIPV) Roofs for Sustainability and Energy Efficiency

    Science.gov (United States)

    2014-04-01

    heated with a small 580,000 British Thermal Units (BTU) Parker water tube boiler . Two air handlers provide conditioned air to the space. The interior...such as PV adhesive failures . The PV system performed as expected, but is highly susceptible to soiling in low-slope roof applications. The BIPV system...roof, but was insufficient for unanticipated issues with the PV system, such as PV adhesive failures . The PV system performed as expected, but is

  16. Extraction and textural characterization of above-ground areas from aerial stereo pairs: a quality assessment

    Science.gov (United States)

    Baillard, C.; Dissard, O.; Jamet, O.; Maître, H.

    Above-ground analysis is a key point to the reconstruction of urban scenes, but it is a difficult task because of the diversity of the involved objects. We propose a new method to above-ground extraction from an aerial stereo pair, which does not require any assumption about object shape or nature. A Digital Surface Model is first produced by a stereoscopic matching stage preserving discontinuities, and then processed by a region-based Markovian classification algorithm. The produced above-ground areas are finally characterized as man-made or natural according to the grey level information. The quality of the results is assessed and discussed.

  17. Modelling of green roofs' hydrologic performance using EPA's SWMM.

    Science.gov (United States)

    Burszta-Adamiak, E; Mrowiec, M

    2013-01-01

    Green roofs significantly affect the increase in water retention and thus the management of rain water in urban areas. In Poland, as in many other European countries, excess rainwater resulting from snowmelt and heavy rainfall contributes to the development of local flooding in urban areas. Opportunities to reduce surface runoff and reduce flood risks are among the reasons why green roofs are more likely to be used also in this country. However, there are relatively few data on their in situ performance. In this study the storm water performance was simulated for the green roofs experimental plots using the Storm Water Management Model (SWMM) with Low Impact Development (LID) Controls module (version 5.0.022). The model consists of many parameters for a particular layer of green roofs but simulation results were unsatisfactory considering the hydrologic response of the green roofs. For the majority of the tested rain events, the Nash coefficient had negative values. It indicates a weak fit between observed and measured flow-rates. Therefore complexity of the LID module does not affect the increase of its accuracy. Further research at a technical scale is needed to determine the role of the green roof slope, vegetation cover and drying process during the inter-event periods.

  18. Hydrological Performance of LECA-Based Roofs in Cold Climates

    Directory of Open Access Journals (Sweden)

    Vladimír Hamouz

    2018-03-01

    Full Text Available Rooftops represent a considerable part of the impervious fractions of urban environments. Detaining and retaining runoff from vegetated rooftops can be a significant contribution to reducing the effects of urbanization, with respect to increased runoff peaks and volumes from precipitation events. However, in climates with limited evapotranspiration, a non-vegetated system is a convenient option for stormwater management. A LECA (lightweight expanded clay aggregate-based roof system was established in the coastal area of Trondheim, Norway in 2016. The roof structure consists of a 200 mm-thick layer of LECA® lightweight aggregate, covered by a concrete pavement. The retention in the LECA-based roof was estimated at 9%, which would be equivalent to 0.27 mm/day for the entire period. The LECA-based configuration provided a detention performance for a peak runoff reduction of 95% (median and for a peak delay of 1 h and 15 min (median, respectively. The relatively high moisture levels in the LECA-based roof did not affect the detention performance. Rooftop retrofitting as a form of source control may contribute to a change in runoff characteristics from conventional roofs. This study of the LECA-based roof configuration presents data and performance indicators for stormwater urban planners with regard to water detention capability.

  19. EVALUATION OF ROOF BOLTING REQUIREMENTS BASED ON IN-MINE ROOF BOLTER DRILLING

    Energy Technology Data Exchange (ETDEWEB)

    Syd S. Peng

    2003-01-15

    In this quarter, the field, theoretical and programming works have been performed toward achieving the research goals set in the proposal. The main accomplishments in this quarter included: (1) laboratory tests have been conducted, (2) with the added trendline analysis method, the accuracy of the data interpretation methodology will be improved and the interfaces and voids can be more reliably detected, (3) method to use torque to thrust ratio as indicator of rock relative hardness has also been explored, and (4) about 80% of the development work for the roof geology mapping program, MRGIS, has completed.

  20. EVALUATION OF ROOF BOLTING REQUIREMENTS BASED ON IN MINE ROOF BOLTER DRILLING

    Energy Technology Data Exchange (ETDEWEB)

    Syd S. Peng

    2003-10-15

    In this quarter, the field, theoretical and programming works have been performed toward achieving the research goals set in the proposal. The main accomplishments in this quarter included: (1) laboratory tests have been conducted, (2) with the added trendline analysis method, the accuracy of the data interpretation methodology will be improved, (3) method to use torque to thrust ratio as indicator of rock relative hardness has also been explored, and (3) about one half of the development work for the roof geology mapping program, MRGIS, has completed.

  1. A Roof for the Lions' House

    Science.gov (United States)

    1978-01-01

    Fans of the National Football League s Detroit Lions don't worry about game day weather. Their magnificent new Pontiac Stadium has a domed, air-supported, fabric roof that admits light but protects the playing field and patrons from the elements. The 80,000-seat Silverdome is the world s largest fabric-covered structure-and aerospace technology played an important part in its construction. The key to economical construction of the Silverdome--and many other types of buildings--is a spinoff of fiber glass Beta yarn coated with Teflon TFE fluorocarbon resin. The big advance it offers is permanency.The team of DuPont, Chemical Fabrics and Birdair have collaborated on a number of fabric structures. Some are supported by air pressure, others by cables alone. Most of the structures are in the recreational category. With conventional construction costs still on the upswing, you're likely to see a great many more permanent facilities enclosed by the aerospace spinoff fabric.

  2. Impact of height and shape of building roof on air quality in urban street canyons

    Science.gov (United States)

    Yassin, Mohamed F.

    2011-09-01

    A building's roof shape and roof height play an important role in determining pollutant concentrations from vehicle emissions and its complex flow patterns within urban street canyons. The impact of the roof shape and height on wind flow and dispersion of gaseous pollutants from vehicle exhaust within urban canyons were investigated numerically using a Computational Fluid Dynamics (CFD) model. Two-dimensional flow and dispersion of gaseous pollutants were analyzed using standard κ- ɛ turbulence model, which was numerically solved based on Reynolds Averaged Navier-Stokes (RANS) equations. The diffusion fields in the urban canyons were examined with three roof heights ( Z H/ H = 0.17, 0.33 and 0.5) and five roof shapes: (1) flat-shaped roof, (2) slanted-shaped roof, (3) downwind wedge-shaped roof, (4) upwind wedge-shaped roof, and (5) trapezoid-shaped roof. The numerical model was validated against the wind tunnels results in order to optimize the turbulence model. The numerical simulations agreed reasonably with the wind tunnel results. The results obtained indicated that the pollutant concentration increased as the roof height decreases. It also decreased with the slanted and trapezoid-shaped roofs but increased with the flat-shaped roof. The pollutant concentration distributions simulated in the present work, indicated that the variability of the roof shapes and roof heights of the buildings are important factors for estimating air quality within urban canyons.

  3. Composition and Diversity of Avian Communities Using a New Urban Habitat: Green Roofs.

    Science.gov (United States)

    Washburn, Brian E; Swearingin, Ryan M; Pullins, Craig K; Rice, Matthew E

    2016-06-01

    Green roofs on buildings are becoming popular and represent a new component of the urban landscape. Public benefits of green roof projects include reduced stormwater runoff, improved air quality, reduced urban heat island effects, and aesthetic values. As part of a city-wide plan, several green roofs have been constructed at Chicago's O'Hare International Airport (ORD). Like some other landscaping features, green roofs on or near an airport might attract wildlife and thus increase the risk of bird-aircraft collisions. During 2007-2011, we conducted a series of studies to evaluate wildlife use of newly constructed green roofs and traditional (gravel) roofs on buildings at ORD. These green roofs were 0.04-1.62 ha in area and consisted of primarily stonecrop species for vegetation. A total of 188 birds were observed using roofs during this research. Of the birds using green roofs, 66, 23, and 4 % were Killdeer, European Starlings, and Mourning Doves, respectively. Killdeer nested on green roofs, whereas the other species perched, foraged, or loafed. Birds used green roofs almost exclusively between May and October. Overall, avian use of the green roofs was minimal and similar to that of buildings with traditional roofs. Although green roofs with other vegetation types might offer forage or cover to birds and thus attract potentially hazardous wildlife, the stonecrop-vegetated green roofs in this study did not increase the risk of bird-aircraft collisions.

  4. Composition and Diversity of Avian Communities Using a New Urban Habitat: Green Roofs

    Science.gov (United States)

    Washburn, Brian E.; Swearingin, Ryan M.; Pullins, Craig K.; Rice, Matthew E.

    2016-06-01

    Green roofs on buildings are becoming popular and represent a new component of the urban landscape. Public benefits of green roof projects include reduced stormwater runoff, improved air quality, reduced urban heat island effects, and aesthetic values. As part of a city-wide plan, several green roofs have been constructed at Chicago's O'Hare International Airport (ORD). Like some other landscaping features, green roofs on or near an airport might attract wildlife and thus increase the risk of bird-aircraft collisions. During 2007-2011, we conducted a series of studies to evaluate wildlife use of newly constructed green roofs and traditional (gravel) roofs on buildings at ORD. These green roofs were 0.04-1.62 ha in area and consisted of primarily stonecrop species for vegetation. A total of 188 birds were observed using roofs during this research. Of the birds using green roofs, 66, 23, and 4 % were Killdeer, European Starlings, and Mourning Doves, respectively. Killdeer nested on green roofs, whereas the other species perched, foraged, or loafed. Birds used green roofs almost exclusively between May and October. Overall, avian use of the green roofs was minimal and similar to that of buildings with traditional roofs. Although green roofs with other vegetation types might offer forage or cover to birds and thus attract potentially hazardous wildlife, the stonecrop-vegetated green roofs in this study did not increase the risk of bird-aircraft collisions.

  5. Javanese House’s Roof (Joglo) with the Opening as a Cooling Energy Provider

    Science.gov (United States)

    Pranoto S, M.

    2018-01-01

    Natural ventilation and air movement could be considered under the heading structural controls as it does not rely on any form of energy supply or mechanical installation but due to its importance for human comfort, it deserves a separate section. Air infiltration can destroy the performance of ventilation systems. Good ventilation design combined with optimum air tightness is needed to ensure energy efficient ventilation. Ultimately, ventilation needs depend on occupancy pattern and building use. A full cost and energy analysis is therefore needed to select an optimum ventilation strategy.The contains of paper is about the element of Javanese house (the roof) as the element of natural ventilation and a cooling energy provider. In this research, The Computational Fluid Dynamics Program, is used to draw and analysis. That tool can be track the pattern and the direction of movement of air also the air velocity in the object of ventilation of the roof Javanese house based. Finally, the ventilation of the roof of this Javanese house can add the velocity of air at indoor, average 0.4 m/s and give the effect of cooling, average 0.7°C.

  6. Soil-roots Strength Performance of Extensive Green Roof by Using Axonopus Compressus

    Science.gov (United States)

    Yusoff, N. A.; Ramli, M. N.; Chik, T. N. T.; Ahmad, H.; Abdullah, M. F.; Kasmin, H.; Embong, Z.

    2016-07-01

    Green roof technology has been proven to provide potential environmental benefits including improved building thermal performance, removal of air pollution and reduced storm water runoff. Installation of green roof also involved soil element usage as a plant growth medium which creates several interactions between both strands. This study was carried out to investigate the soil-roots strength performance of green roof at different construction period up to 4 months. Axonopus compressus (pearl grass) was planted in a ExE test plot with a designated suitable soil medium. Direct shear test was conducted for each plot to determine the soil shear strength according to different construction period. In addition, some basic geotechnical testing also been carried out. The results showed that the shear strength of soil sample increased over different construction period of 1st, 2nd, 3rd and 4th month with average result 3.81 kPa, 5.55 kPa, 6.05 kPa and 6.48 kPa respectively. Shear strength of rooted soil samples was higher than the soil samples without roots (control sample). In conclusion, increment of soil-roots shear strength was due to root growth over the time. The soil-roots shear strength development of Axonopus compressus can be expressed in a linear equation as: y = 0.851x + 3.345, where y = shear stress and x = time.

  7. ANALYSIS OF WATER RELATIONS OF SUBSTRATES USED IN GREEN ROOF SYSTEMS

    Directory of Open Access Journals (Sweden)

    Anna Baryła

    2014-10-01

    Full Text Available Green roofs, as the restoration of biologically active area, are fairly common and effective method of storm water management in urban areas. Depend on the design of the green roof and the type of substrate, they are able to retain 50–90% of rainwater. The aim of the study was to determine the physicochemical properties of two substrates used in the construction of green roofs (intensive and extensive. Water retention of substrates was compared to water retention of substrates undelined with the drainage layer made from crushed autoclaved aerated concrete. In the experiment, which uses drainage layer, higher drying the top layer of the substrate was observed, which may be related to high water absorption drainage material. The effluent from the substrate using aerated concrete as a drainage layer amounted to an average of 22–51% of the volume of water supplied to the extensive substrate, whereas 19–46% of the volume of water supplied to the intensive substrate. The effluent from the substrate without the drainage layer amounted 40-48% of the volume of water supplied.

  8. Coupled Finite Volume and Finite Element Method Analysis of a Complex Large-Span Roof Structure

    Science.gov (United States)

    Szafran, J.; Juszczyk, K.; Kamiński, M.

    2017-12-01

    The main goal of this paper is to present coupled Computational Fluid Dynamics and structural analysis for the precise determination of wind impact on internal forces and deformations of structural elements of a longspan roof structure. The Finite Volume Method (FVM) serves for a solution of the fluid flow problem to model the air flow around the structure, whose results are applied in turn as the boundary tractions in the Finite Element Method problem structural solution for the linear elastostatics with small deformations. The first part is carried out with the use of ANSYS 15.0 computer system, whereas the FEM system Robot supports stress analysis in particular roof members. A comparison of the wind pressure distribution throughout the roof surface shows some differences with respect to that available in the engineering designing codes like Eurocode, which deserves separate further numerical studies. Coupling of these two separate numerical techniques appears to be promising in view of future computational models of stochastic nature in large scale structural systems due to the stochastic perturbation method.

  9. Aboveground Tree Biomass for Pinus ponderosa in Northeastern California

    Directory of Open Access Journals (Sweden)

    Todd A. Hamilton

    2013-03-01

    Full Text Available Forest managers need accurate biomass equations to plan thinning for fuel reduction or energy production. Estimates of carbon sequestration also rely upon such equations. The current allometric equations for ponderosa pine (Pinus ponderosa commonly employed for California forests were developed elsewhere, and are often applied without consideration potential for spatial or temporal variability. Individual-tree aboveground biomass allometric equations are presented from an analysis of 79 felled trees from four separate management units at Blacks Mountain Experimental Forest: one unthinned and three separate thinned units. A simultaneous set of allometric equations for foliage, branch and bole biomass were developed as well as branch-level equations for wood and foliage. Foliage biomass relationships varied substantially between units while branch and bole biomass estimates were more stable across a range of stand conditions. Trees of a given breast height diameter and crown ratio in thinned stands had more foliage biomass, but slightly less branch biomass than those in an unthinned stand. The observed variability in biomass relationships within Blacks Mountain Experimental Forest suggests that users should consider how well the data used to develop a selected model relate to the conditions in any given application.

  10. Aboveground mechanical stimuli affect belowground plant-plant communication.

    Science.gov (United States)

    Elhakeem, Ali; Markovic, Dimitrije; Broberg, Anders; Anten, Niels P R; Ninkovic, Velemir

    2018-01-01

    Plants can detect the presence of their neighbours and modify their growth behaviour accordingly. But the extent to which this neighbour detection is mediated by abiotic stressors is not well known. In this study we tested the acclimation response of Zea mays L. seedlings through belowground interactions to the presence of their siblings exposed to brief mechano stimuli. Maize seedling simultaneously shared the growth solution of touched plants or they were transferred to the growth solution of previously touched plants. We tested the growth preferences of newly germinated seedlings toward the growth solution of touched (T_solution) or untouched plants (C_solution). The primary root of the newly germinated seedlings grew significantly less towards T_solution than to C_solution. Plants transferred to T_solution allocated more biomass to shoots and less to roots. While plants that simultaneously shared their growth solution with the touched plants produced more biomass. Results show that plant responses to neighbours can be modified by aboveground abiotic stress to those neighbours and suggest that these modifications are mediated by belowground interactions.

  11. Aboveground mechanical stimuli affect belowground plant-plant communication.

    Directory of Open Access Journals (Sweden)

    Ali Elhakeem

    Full Text Available Plants can detect the presence of their neighbours and modify their growth behaviour accordingly. But the extent to which this neighbour detection is mediated by abiotic stressors is not well known. In this study we tested the acclimation response of Zea mays L. seedlings through belowground interactions to the presence of their siblings exposed to brief mechano stimuli. Maize seedling simultaneously shared the growth solution of touched plants or they were transferred to the growth solution of previously touched plants. We tested the growth preferences of newly germinated seedlings toward the growth solution of touched (T_solution or untouched plants (C_solution. The primary root of the newly germinated seedlings grew significantly less towards T_solution than to C_solution. Plants transferred to T_solution allocated more biomass to shoots and less to roots. While plants that simultaneously shared their growth solution with the touched plants produced more biomass. Results show that plant responses to neighbours can be modified by aboveground abiotic stress to those neighbours and suggest that these modifications are mediated by belowground interactions.

  12. Global patterns of aboveground carbon stock and sequestration in mangroves

    Directory of Open Access Journals (Sweden)

    GUSTAVO C.D. ESTRADA

    Full Text Available ABSTRACT In order to contribute to understand the factors that control the provisioning of the ecosystem service of carbon storage by mangroves, data on carbon stock and sequestration in the aboveground biomass (AGB from 73 articles were averaged and tested for the dependence on latitude, climatic parameters, physiographic types and age. Global means of carbon stock (78.0 ± 64.5 tC.ha-1 and sequestration (2.9 ± 2.2 tC.ha-1.yr-1 showed that mangroves are among the forest ecosystems with greater capacity of carbon storage in AGB per area. On the global scale, carbon stock increases toward the equator (R²=0.22 and is dependent on 13 climatic parameters, which can be integrated in the following predictive equation: Carbon Stock in AGB = -16.342 + (8.341 x Isothermality + (0.021 x Annual Precipitation [R²=0.34; p < 0.05]. It was shown that almost 70% of carbon stock variability is explained by age. Carbon stock and sequestration also vary according to physiographic types, indicating the importance of hydroperiod and edaphic parameters to the local variability of carbon stock. By demonstrating the contribution of local and regional-global factors to carbon stock, this study provides information to the forecast of the effects of future climate changes and local anthropogenic forcings on this ecosystem service.

  13. Performance analysis and experimental study on rainfall water purification with an extensive green roof matrix layer in Shanghai, China.

    Science.gov (United States)

    Guo, Jiankang; Zhang, Yanting; Che, Shengquan

    2018-02-01

    Current research has validated the purification of rainwater by a substrate layer of green roofs to some extent, though the effects of the substrate layer on rainwater purification have not been adequately quantified. The present study set up nine extensive green roof experiment combinations based on the current conditions of precipitation characteristics observed in Shanghai, China. Different rain with pollutants were simulated, and the orthogonal design L9 (33) test was conducted to measure purification performance. The purification influences of the extensive green roof substrate layer were quantitatively analyzed in Shanghai to optimize the thickness, proportion of substrate, and sodium polyacrylate content. The experimental outcomes resulted in ammonium nitrogen (NH 4 + -N), lead (Pb), and zinc (Zn) removal of up to 93.87%, 98.81%, and 94.55% in the artificial rainfall, respectively, and NH 4 + -N, Pb, and Zn event mean concentration (EMC) was depressed to 0.263 mg/L, 0.002 mg/L and 0.018 mg/L, respectively, which were all well below the pollutant concentrations of artificial rainfall. With reference to the rainfall chemical characteristics of Shanghai, a combination of a 200 mm thickness, proportions of 1:1:2 of Loam: Perlite: Cocopeat and 2 g/L sodium polyacrylate content was suggested for the design of an extensive green roof substrate to purify NH 4 + -N, Pb and Zn.

  14. Siberian Boreal Forest Aboveground Biomass and Fire Scar Maps, Russia, 1969-2007

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides 30-meter resolution mapped estimates of Cajander larch (Larix cajanderi) aboveground biomass (AGB), circa 2007, and a map of burn perimeters...

  15. Relationships at the aboveground-belowground interface: plants, soil biota and soil processes

    NARCIS (Netherlands)

    Porazinska, D.L.; Bardgett, R.D.; Postma-Blaauw, M.B.; Hunt, H.W.; Parsons, A.N.; Seastedt, T.R.; Wall, D.M.

    2003-01-01

    Interactions at the aboveground-below ground interface provide important feedbacks that regulate ecosystem processes. Organisms within soil food webs are involved in processes of decomposition and nutrient mineralization, and their abundance and activity have been linked to plant ecophysiological

  16. Technical basis for the aboveground structure failure and associated represented hazardous conditions

    International Nuclear Information System (INIS)

    GOETZ, T.G.

    2003-01-01

    This technical basis document describes the risk binning process and the technical basis for assigning risk bins for the aboveground structure failure representative accident and associated represented hazardous conditions. This document was developed to support the documented safety analysis

  17. Inclusion of cool roofs in nonresidential Title 24 prescriptive requirements

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, Ronnen; Akbari, Hashem; Konopacki, Steve; Bretz, Sarah

    2002-12-15

    Roofs that have high solar reflectance (high ability to reflect sunlight) and high thermal emittance (high ability to radiate heat) tend to stay cool in the sun. The same is true of low-emittance roofs with exceptionally high solar reflectance. Substituting a cool roof for a noncool roof tends to decrease cooling electricity use, cooling power demand, and cooling-equipment capacity requirements, while slightly increasing heating energy consumption. Cool roofs can also lower the ambient air temperature in summer, slowing ozone formation and increasing human comfort. DOE-2.1E building energy simulations indicate that use of a cool roofing material on a prototypical California nonresidential building with a low-sloped roof yields average annual cooling energy savings of approximately 300 kWh/1000 ft2 [3.2 kWh/m2], average annual natural gas deficits of 4.9 therm/1000 ft2 [5.6 MJ/m2], average source energy savings of 2.6 MBTU/1000 ft2 [30 MJ/m2], and average peak power demand savings of 0. 19 kW/1000 ft2 [2.1 W/m2]. The 15-year net present value (NPV) of energy savings averages $450/1000 ft2 [$4.90/m2] with time dependent valuation (TDV), and $370/1000 ft2 [$4.00/m2] without TDV. When cost savings from downsizing cooling equipment are included, the average total savings (15-year NPV + equipment savings) rises to $550/1000 ft2 [$5.90/m2] with TDV, and to $470/1000 ft2 [$5.00/m2] without TDV. Total savings range from 0.18 to 0.77 $/ft2 [1.90 to 8.30 $/m2] with TDV, and from 0.16 to 0.66 $/ft2 [1.70 to 7.10 $/m2] without TDV, across California's 16 climate zones. The typical cost premium for a cool roof is 0.00 to 0.20 $/ft2 [0.00 to 2.20 $/m2]. Cool roofs with premiums up to $0.20/ft2 [$2.20/m2] are expected to be cost effective in climate zones 2 through 16; those with premiums not exceeding $0.18/ft2 [$1.90/m2] are expected to be also cost effective in climate zone 1. Hence, this study recommends that the year-2005 California building energy efficiency code (Title

  18. Inclusion of cool roofs in nonresidential Title 24 prescriptive requirements

    International Nuclear Information System (INIS)

    Levinson, Ronnen; Akbari, Hashem; Konopacki, Steve; Bretz, Sarah

    2005-01-01

    Roofs that have high solar reflectance (high ability to reflect sunlight) and high thermal emittance (high ability to radiate heat) tend to stay cool in the sun. The same is true of low-emittance roofs with exceptionally high solar reflectance. Substituting a cool roof for a non-cool roof tends to decrease cooling electricity use, cooling power demand, and cooling-equipment capacity requirements, while slightly increasing heating energy consumption. Cool roofs can also lower citywide ambient air temperature in summer, slowing ozone formation and increasing human comfort. DOE-2.1E building energy simulations indicate that use of a cool roofing material on a prototypical California nonresidential (NR) building with a low-sloped roof yields average annual cooling energy savings of approximately 3.2 kW h/m 2 (300 kW h/1000 ft 2 ), average annual natural gas deficits of 5.6 MJ/m 2 (4.9 therm/1000 ft 2 ), average annual source energy savings of 30 MJ/m 2 (2.6 MBTU/1000 ft 2 ), and average peak power demand savings of 2.1 W/m 2 (0.19 kW/1000 ft 2 ). The 15-year net present value (NPV) of energy savings averages $4.90/m 2 ($450/1000 ft 2 ) with time-dependent valuation (TDV), and $4.00/m 2 ($370/1000 ft 2 ) without TDV. When cost savings from downsizing cooling equipment are included, the average total savings (15-year NPV+equipment savings) rises to $5.90/m 2 ($550/1000 ft 2 ) with TDV, and to $5.00/m 2 ($470/1000 ft 2 ) without TDV. Total savings range from 1.90 to 8.30 $/m 2 (0.18-0.77 $/ft 2 ) with TDV, and from 1.70 to 7.10 $/m 2 (0.16-0.66 $/ft 2 ) without TDV, across California's 16 climate zones. The typical cost premium for a cool roof is 0.00-2.20 $/m 2 (0.00-0.20 $/ft 2 ). Cool roofs with premiums up to $2.20/m 2 ($0.20/ft 2 ) are expected to be cost effective in climate zones 2-16; those with premiums not exceeding $1.90/m 2 ($0.18/ft 2 ) are expected to be also cost effective in climate zone 1. Hence, this study recommends that the year-2005 California

  19. Experimental study on foam coverage on simulated longwall roof

    Science.gov (United States)

    Reed, W.R.; Zheng, Y.; Klima, S.; Shahan, M.R.; Beck, T.W.

    2018-01-01

    Testing was conducted to determine the ability of foam to maintain roof coverage in a simulated longwall mining environment. Approximately 27 percent of respirable coal mine dust can be attributed to longwall shield movement, and developing controls for this dust source has been difficult. The application of foam is a possible dust control method for this source. Laboratory testing of two foam agents was conducted to determine the ability of the foam to adhere to a simulated longwall face roof surface. Two different foam generation methods were used: compressed air and blower air. Using a new imaging technology, image processing and analysis utilizing ImageJ software produced quantifiable results of foam roof coverage. For compressed air foam in 3.3 m/s (650 fpm) ventilation, 98 percent of agent A was intact while 95 percent of agent B was intact on the roof at three minutes after application. At 30 minutes after application, 94 percent of agent A was intact while only 20 percent of agent B remained. For blower air in 3.3 m/s (650 fpm) ventilation, the results were dependent upon nozzle type. Three different nozzles were tested. At 30 min after application, 74 to 92 percent of foam agent A remained, while 3 to 50 percent of foam agent B remained. Compressed air foam seems to remain intact for longer durations and is easier to apply than blower air foam. However, more water drained from the foam when using compressed air foam, which demonstrates that blower air foam retains more water at the roof surface. Agent A seemed to be the better performer as far as roof application is concerned. This testing demonstrates that roof application of foam is feasible and is able to withstand a typical face ventilation velocity, establishing this technique’s potential for longwall shield dust control. PMID:29563765

  20. Manipulating soil microbial communities in extensive green roof substrates.

    Science.gov (United States)

    Molineux, Chloe J; Connop, Stuart P; Gange, Alan C

    2014-09-15

    There has been very little investigation into the soil microbial community on green roofs, yet this below ground habitat is vital for ecosystem functioning. Green roofs are often harsh environments that would greatly benefit from having a healthy microbial system, allowing efficient nutrient cycling and a degree of drought tolerance in dry summer months. To test if green roof microbial communities could be manipulated, we added mycorrhizal fungi and a microbial mixture ('compost tea') to green roof rootzones, composed mainly of crushed brick or crushed concrete. The study revealed that growing media type and depth play a vital role in the microbial ecology of green roofs. There are complex relationships between depth and type of substrate and the biomass of different microbial groups, with no clear pattern being observed. Following the addition of inoculants, bacterial groups tended to increase in biomass in shallower substrates, whereas fungal biomass change was dependent on depth and type of substrate. Increased fungal biomass was found in shallow plots containing more crushed concrete and deeper plots containing more crushed brick where compost tea (a live mixture of beneficial bacteria) was added, perhaps due to the presence of helper bacteria for arbuscular mycorrhizal fungi (AMF). Often there was not an additive affect of the microbial inoculations but instead an antagonistic interaction between the added AM fungi and the compost tea. This suggests that some species of microbes may not be compatible with others, as competition for limited resources occurs within the various substrates. The overall results suggest that microbial inoculations of green roof habitats are sustainable. They need only be done once for increased biomass to be found in subsequent years, indicating that this is a novel and viable method of enhancing roof community composition. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Releasability of asbestos fibers from weathered roof cement.

    Science.gov (United States)

    Oberta, Andrew F; Poye, Lee; Compton, Steven P

    2018-03-26

    Chrysotile asbestos fibers were added to roofing products, including roof cement, for several decades. The fibers were described as "encapsulated" and therefore incapable of being released, an assertion that is disproved by the study reported herein. Three test panels of roof cement from the original container were exposed to ambient weathering in 2015 and 2016. Two panels were then sampled using the ASTM D5755 microvacuum method. Sampling revealed a light brown sub-layer under the dark brown surface layer, both of which crumbled and became friable during sampling. Analysis of the microvacuum samples with transmission electron microscopy showed that the material on the two panels contained 4,432,000 and 3,320,000 asbestos structures per cm² with nearly all of the structures consisting of fibers less than 5 µm long. Energy dispersive spectrometry determined that none of the fibers reported were coated with asphalt. The presence of free fibers were confirmed by direct examination of the surfaces of the panels and of dust released from handling the panels via scanning electron microscopy. This study confirmed the releasability of uncoated asbestos fibers from dried roof cement that was indicated in two previous studies published in 2007 and 2010. These results suggest that the finding of the 5th Circuit Court in 1997 that uncoated airborne asbestos fibers cannot be released from roof cement, and therefore do not present a potential exposure by inhalation, was erroneous in retrospect. Theexemption of roof cement from regulation under the Occupational Safety and Health Administration Construction Industry Standard for asbestos by the Court should not be relied on by employers of workers who remove weathered asbestos-containing roof cement, and precautions should be taken against exposure to airborne asbestos fibers during this work.

  2. Selection of methods and parameters for forced weakening of roofing in stoping faces

    Energy Technology Data Exchange (ETDEWEB)

    Bekbulatov, A K

    1982-01-01

    The use of the method of advanced shooting on mines of different basins of the country indicated the need to generalize results of work for forced weakening of the roofing on mines in the sector in order to create ''Instructions For Selecting the Methods and Parameters of Forced Weakening of Roofing in the Stoping Faces'' with the participation of the basin scientific research institutes under the leadership of the VNIMI. The main method of weakening which has been introduced in the Karaganda basin is frontal shooting with the use of torpedo-charges. Shooting of the roofing in order reduce the intensity of the primary settling of the main roofing is done in parallel and perpendicular plans. With the parallel plan, the wells are drilled out from the adjoining roadways parallel to the stoping face, and with perpendicular plan, from the assembly chamber perpendicular to the stoping face. In order to reduce the intensity of secondary settling of the main roofing, the parallel or parallel-inclined method is used in designing of the torpedo-charge and the torpedo-head. It is reported that the torpedo-charge is a set of individual torpedos made of polyethylene pipes of length 1500 mm connected to each other with the help of couplings and splints. The torpedo-head consists of a polyethylene pipe of length 700 mm with wall thickness 15-17 mm filled with bulk explosives. Within the torpedo there are 2 explosive charges with electric-detonators for instantaneous action. The main cables of the explosive circuit are connected to the electric detonators and are passed through the packing pipe. In the improved design of the torpedo-head and the torpedo-charge, there are no metal parts. This excludes blow-out of particles of incandescent metal during the explosion and increases the level of work safety. The torpedo-charge is installed manually or mechanically with the help of a metal guide (rammer) which is removed from the well after it delivers the torpedo-charge.

  3. [Spatial distribution of aboveground biomass of shrubs in Tianlaochi catchment of the Qilian Mountains].

    Science.gov (United States)

    Liang, Bei; Di, Li; Zhao, Chuan-Yan; Peng, Shou-Zhang; Peng, Huan-Hua; Wang, Chao

    2014-02-01

    This study estimated the spatial distribution of the aboveground biomass of shrubs in the Tianlaochi catchment of Qilian Mountains based on the field survey and remote sensing data. A relationship model of the aboveground biomass and its feasibly measured factors (i. e. , canopy perimeter and plant height) was built. The land use was classified by object-oriented technique with the high resolution image (GeoEye-1) of the study area, and the distribution of shrub coverage was extracted. Then the total aboveground biomass of shrubs in the study area was estimated by the relationship model with the distribution of shrub coverage. The results showed that the aboveground biomass of shrubs in the study area was 1.8 x 10(3) t and the aboveground biomass per unit area was 1598.45 kg x m(-2). The distribution of shrubs mainly was at altitudes of 3000-3700 m, and the aboveground biomass of shrubs on the sunny slope (1.15 x 10(3) t) was higher than that on the shady slope (0.65 x 10(3) t).

  4. Developing a generalized allometric equation for aboveground biomass estimation

    Science.gov (United States)

    Xu, Q.; Balamuta, J. J.; Greenberg, J. A.; Li, B.; Man, A.; Xu, Z.

    2015-12-01

    A key potential uncertainty in estimating carbon stocks across multiple scales stems from the use of empirically calibrated allometric equations, which estimate aboveground biomass (AGB) from plant characteristics such as diameter at breast height (DBH) and/or height (H). The equations themselves contain significant and, at times, poorly characterized errors. Species-specific equations may be missing. Plant responses to their local biophysical environment may lead to spatially varying allometric relationships. The structural predictor may be difficult or impossible to measure accurately, particularly when derived from remote sensing data. All of these issues may lead to significant and spatially varying uncertainties in the estimation of AGB that are unexplored in the literature. We sought to quantify the errors in predicting AGB at the tree and plot level for vegetation plots in California. To accomplish this, we derived a generalized allometric equation (GAE) which we used to model the AGB on a full set of tree information such as DBH, H, taxonomy, and biophysical environment. The GAE was derived using published allometric equations in the GlobAllomeTree database. The equations were sparse in details about the error since authors provide the coefficient of determination (R2) and the sample size. A more realistic simulation of tree AGB should also contain the noise that was not captured by the allometric equation. We derived an empirically corrected variance estimate for the amount of noise to represent the errors in the real biomass. Also, we accounted for the hierarchical relationship between different species by treating each taxonomic level as a covariate nested within a higher taxonomic level (e.g. species contribution of each different covariate in estimating the AGB of trees. Lastly, we applied the GAE to an existing vegetation plot database - Forest Inventory and Analysis database - to derive per-tree and per-plot AGB estimations, their errors, and how

  5. A comparative analysis of selected parameters of roofing used in the Polish construction industry

    Directory of Open Access Journals (Sweden)

    Radziszewska-Zielina Elżbieta

    2014-06-01

    Full Text Available Roofing is an important element in the construction of the roof. It is also one of the essential elements of the whole building. The choice of roofing should depend on technical parameters that affect the quality of the materials used and the price. The present paper is a comparative analysis of the properties of five roofing materials selected as examples with respect to twelve parameters. As can be seen from the comparative analysis of the roofing parameters, roofing tile is by far the best material, receiving the highest score in the ranking

  6. Retention performance of green roofs in three different climate regions

    Science.gov (United States)

    Sims, Andrew W.; Robinson, Clare E.; Smart, Charles C.; Voogt, James A.; Hay, Geoffrey J.; Lundholm, Jeremey T.; Powers, Brandon; O'Carroll, Denis M.

    2016-11-01

    Green roofs are becoming increasingly popular for moderating stormwater runoff in urban areas. This study investigated the impact different climates have on the retention performance of identical green roofs installed in London Ontario (humid continental), Calgary Alberta (semi-arid, continental), and Halifax Nova Scotia (humid, maritime). Drier climates were found to have greater percent cumulative stormwater retention with Calgary (67%) having significantly better percent retention than both London (48%) and Halifax (34%). However, over the same study period the green roof in London retained the greatest depth of stormwater (598 mm), followed by the green roof in Halifax (471 mm) and then Calgary (411 mm). The impact of climate was largest for medium sized storms where the antecedent moisture condition (AMC) at the beginning of a rainfall event governs retention performance. Importantly AMC was a very good predictor of stormwater retention, with similar retention at all three sites for a given AMC, emphasizing that AMC is a relevant indicator of retention performance in any climate. For large rainfall events (i.e., >45 mm) green roof average retention ranged between 16% and 29% in all cities. Overall, drier climates have superior retention due to lower AMC in the media. However, moderate and wet climates still provide substantial total volume reduction benefits.

  7. A pilot study to evaluate runoff quantity from green roofs.

    Science.gov (United States)

    Lee, Ju Young; Lee, Min Jung; Han, Mooyoung

    2015-04-01

    The use of green roofs is gaining increased recognition in many countries as a solution that can be used to improve environmental quality and reduce runoff quantity. To achieve these goals, pilot-scale green roof assemblies have been constructed and operated in an urban setting. From a stormwater management perspective, green roofs are 42.8-60.8% effective in reducing runoff for 200 mm soil depth and 13.8-34.4% effective in reducing runoff for 150 mm soil depth. By using Spearman rank correlation analysis, high rainfall intensity was shown to have a negative relationship with delayed occurrence time, demonstrating that the soil media in green roofs do not efficiently retain rainwater. Increasing the number of antecedent dry days can help to improve water retention capacity and delay occurrence time. From the viewpoint of runoff water quality, green roofs are regarded as the best management practice by filtration and adsorption through growth media (soil). Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Residential roof condition assessment system using deep learning

    Science.gov (United States)

    Wang, Fan; Kerekes, John P.; Xu, Zhuoyi; Wang, Yandong

    2018-01-01

    The emergence of high resolution (HR) and ultra high resolution (UHR) airborne remote sensing imagery is enabling humans to move beyond traditional land cover analysis applications to the detailed characterization of surface objects. A residential roof condition assessment method using techniques from deep learning is presented. The proposed method operates on individual roofs and divides the task into two stages: (1) roof segmentation, followed by (2) condition classification of the segmented roof regions. As the first step in this process, a self-tuning method is proposed to segment the images into small homogeneous areas. The segmentation is initialized with simple linear iterative clustering followed by deep learned feature extraction and region merging, with the optimal result selected by an unsupervised index, Q. After the segmentation, a pretrained residual network is fine-tuned on the augmented roof segments using a proposed k-pixel extension technique for classification. The effectiveness of the proposed algorithm was demonstrated on both HR and UHR imagery collected by EagleView over different study sites. The proposed algorithm has yielded promising results and has outperformed traditional machine learning methods using hand-crafted features.

  9. The Influence of Hydrologic Parameters on the Hydraulic Efficiency of an Extensive Green Roof in Mediterranean Area

    Directory of Open Access Journals (Sweden)

    Giuseppina Garofalo

    2016-01-01

    Full Text Available In an urban environment, green roofs represent a sustainable solution for mitigating stormwater volumes and hydrograph peaks. So far, many literature studies have investigated the hydraulic efficiency and the subsurface runoff coefficient of green roofs, showing their strong variability according to several factors, including the characteristics of storm events. Furthermore, only few studies have focused on the hydraulic efficiency of green roofs under Mediterranean climate conditions and defined the influencing hydrological parameters on the subsurface runoff coefficient. Nevertheless, for designing purposes, it is crucial to properly assess the subsurface runoff coefficient of a given green roof under specific climate conditions and its influencing factors. This study intends to, firstly, evaluate the subsurface runoff coefficient at daily and event-time scales for a given green roof, through a conceptual model implemented in SWMM. The model was loaded with both daily and 1-min rainfall data from two Mediterranean climate sites, one in Thessaloniki, Greece and one in Cosenza, Italy, respectively. Then, the most influencing hydrological parameters were examined through a statistical regression analysis. The findings show that the daily subsurface runoff coefficient is 0.70 for both sites, while the event-based one is 0.79 with a standard deviation of 0.23 for the site in Cosenza, Italy. The multiple linear regression analysis revealed that the influencing parameters are the rainfall intensity and antecedent dry weather period with a confidence level of 95%. This study demonstrated that, due to the high variability of the subsurface runoff coefficient, the use of a unique value for design purposes is inappropriate and that a preliminary estimation could be obtained as a function of the total rainfall depth and the antecedent dry weather period by using the validated multi-regression relationship which is site specific.

  10. EVALUATION OF ROOF BOLTING REQUIREMENTS BASED ON IN-MINE ROOF BOLTER DRILLING

    Energy Technology Data Exchange (ETDEWEB)

    Syd S. Peng

    2004-04-15

    A one-year non-cost extension has been granted for this project. In this quarter, the field, theoretical and programming works have been performed toward achieving the research goals set in the proposal. The main accomplishments in this quarter included: (1) laboratory tests have been conducted, (2) with the added trendline analysis method, the accuracy of the data interpretation methodology will be improved and the interfaces and voids can be more reliably detected, (3) method to use torque to thrust ratio as indicator of rock relative hardness has also been explored, and (3) about 80% of the development work for the roof geology mapping program, MRGIS, has completed and a special version of the program is in the field testing stage.

  11. EVALUATION OF ROOF BOLTING REQUIREMENTS BASED ON IN-MINE ROOF BOLTER DRILLING

    Energy Technology Data Exchange (ETDEWEB)

    Syd S. Peng

    2004-09-15

    In this quarter, the field, theoretical and programming works have been performed toward achieving the research goals set in the proposal. The main accomplishments in this quarter included: (1) two more sets of field tests have been conducted in an underground coal mine, (2) optimization studies of the control parameters have been conducted, (3) method to use torque to thrust ratio as indicator of rock relative hardness has also been explored, and (3) about 97% of the development work for the roof geology mapping program, MRGIS, has completed, (4) A special version of the geology mapping program for a limestone mine has been developed. The field test for the software and hardware has been successfully finished.

  12. Integrated Modelling and Performance Analysis of Green Roof Technologies in Urban Environments

    Science.gov (United States)

    Liu, Xi; Mijic, Ana; Maksimovic, Cedo

    2014-05-01

    As a result of the changing global climate and increase in urbanisation, the behaviour of the urban environment has been significantly altered, causing an increase in both the frequency of extreme weather events, such as flooding and drought, and also the associated costs. Moreover, uncontrolled or inadequately planned urbanisation can exacerbate the damage. The Blue-Green Dream (BGD) project therefore develops a series of components for urban areas that link urban vegetated areas (green infrastructure) with existing urban water (blue) systems, which will enhance the synergy of urban blue and green systems and provide effective, multifunctional BGD solutions to support urban adaptation to future climatic changes. Coupled with new urban water management technologies and engineering, multifunctional benefits can be gained. Some of the technologies associated with BGD solutions include green roofs, swales that might deal with runoff more effectively and urban river restoration that can produce benefits similar to those produced from sustainable urban drainage systems (SUDS). For effective implementation of these technologies, however, appropriate tools and methodologies for designing and modelling BGD solutions are required to be embedded within urban drainage models. Although several software packages are available for modelling urban drainage, the way in which green roofs and other BGD solutions are integrated into these models is not yet fully developed and documented. This study develops a physically based mass and energy balance model to monitor, test and quantitatively evaluate green roof technology for integrated BGD solutions. The assessment of environmental benefits will be limited to three aspects: (1) reduction of the total runoff volume, (2) delay in the initiation of runoff, and (3) reduction of building energy consumption, rather than water quality, visual, social or economic impacts. This physically based model represents water and heat dynamics in a

  13. Theoretical evaluation of thermal and energy performance of tropical green roofs

    International Nuclear Information System (INIS)

    Tsang, S.W.; Jim, C.Y.

    2011-01-01

    The thermal and energy efficiency of tropical green roofs is assessed by a theoretical model to clarify the contribution of underlying factors. The suitability of 1400 high-rise public housing blocks in Hong Kong for rooftop greening was assessed by remote sensing images. Weather and microclimatic-soil monitoring data of an experimental green roof provided the basis for computations. Roof greening prevented a huge amount of solar energy at 43.9 TJ in one summer from penetrating the buildings to bring significant energy saving. Thermal performance of humid-tropical green roofs, with greater latent heat dissipation, is twice more effective than the temperate ones. The energy balance model shows that solar energy absorption by bare and green roofs depends on shortwave rather than longwave radiation. Heat flux into a building indicates a one-day time lag after a sunshine day. With restricted evapotranspiration, bare roofs have more sensible heat and heat storage than green roofs. The bare roof albedo of 0.15, comparing with 0.30 of green roof, renders 75% higher heat storage. Small increase in convection coefficient from 12 to 16 could amplify 24% and 45% of latent heat dissipation respectively for bare and green roofs. Doubling the soil water availability could halve the heat storage of green roofs. -- Highlights: → We developed a theoretical model to calculate the thermal performance of tropical green roofs. → Bare roofs have more sensible heat and heat storage than green roofs. → Latent heat dissipation of tropical green roofs is twice that of temperate counterparts. → Heat flux through the roof into a building demonstrates a one-day time lag after a long sunshine day. → Green roofs can block 43.9 TJ of solar energy penetration into public housing buildings in one summer.

  14. Mathematical modeling of large floating roof reservoir temperature arena

    Directory of Open Access Journals (Sweden)

    Liu Yang

    2018-03-01

    Full Text Available The current study is a simplification of related components of large floating roof tank and modeling for three dimensional temperature field of large floating roof tank. The heat transfer involves its transfer between the hot fluid in the oil tank, between the hot fluid and the tank wall and between the tank wall and the external environment. The mathematical model of heat transfer and flow of oil in the tank simulates the temperature field of oil in tank. Oil temperature field of large floating roof tank is obtained by numerical simulation, map the curve of central temperature dynamics with time and analyze axial and radial temperature of storage tank. It determines the distribution of low temperature storage tank location based on the thickness of the reservoir temperature. Finally, it compared the calculated results and the field test data; eventually validated the calculated results based on the experimental results.

  15. Plant functional traits predict green roof ecosystem services.

    Science.gov (United States)

    Lundholm, Jeremy; Tran, Stephanie; Gebert, Luke

    2015-02-17

    Plants make important contributions to the services provided by engineered ecosystems such as green roofs. Ecologists use plant species traits as generic predictors of geographical distribution, interactions with other species, and ecosystem functioning, but this approach has been little used to optimize engineered ecosystems. Four plant species traits (height, individual leaf area, specific leaf area, and leaf dry matter content) were evaluated as predictors of ecosystem properties and services in a modular green roof system planted with 21 species. Six indicators of ecosystem services, incorporating thermal, hydrological, water quality, and carbon sequestration functions, were predicted by the four plant traits directly or indirectly via their effects on aggregate ecosystem properties, including canopy density and albedo. Species average height and specific leaf area were the most useful traits, predicting several services via effects on canopy density or growth rate. This study demonstrates that easily measured plant traits can be used to select species to optimize green roof performance across multiple key services.

  16. Solare Cell Roof Tile And Method Of Forming Same

    Science.gov (United States)

    Hanoka, Jack I.; Real, Markus

    1999-11-16

    A solar cell roof tile includes a front support layer, a transparent encapsulant layer, a plurality of interconnected solar cells and a backskin layer. The front support layer is formed of light transmitting material and has first and second surfaces. The transparent encapsulant layer is disposed adjacent the second surface of the front support layer. The interconnected solar cells has a first surface disposed adjacent the transparent encapsulant layer. The backskin layer has a first surface disposed adjacent a second surface of the interconnected solar cells, wherein a portion of the backskin layer wraps around and contacts the first surface of the front support layer to form the border region. A portion of the border region has an extended width. The solar cell roof tile may have stand-offs disposed on the extended width border region for providing vertical spacing with respect to an adjacent solar cell roof tile.

  17. Vegetation composition and structure significantly influence green roof performance

    Energy Technology Data Exchange (ETDEWEB)

    Dunnett, N.; Nagase, A.; Booth, R.; Grime, P. [Sheffield Univ., Sheffield (United Kingdom). Dept. of Landscape Architecture

    2005-07-01

    The majority of published literature on green roofs contains little specific information on the contribution of plants to the various functions and properties of green roofs. This paper reviewed previously published material in an attempt to shed light on the role of vegetation composition in green roof systems, with specific reference to hydrology and biodiversity support. Two ongoing experiments at the University of Sheffield were then considered: (1) a comparison of quality and quantity of runoff from different types of vegetation; and (2) a comparison of flowering seasons and biodiversity support of different vegetation. Results of the studies showed that there was no general pattern of variation in runoff that could be related to vegetation complexity or taxonomic composition of the communities. During the winter months, high precipitation quickly saturated the soil and percolate losses were similar for all treatments. In the summer, throughflow losses differed between treatments in relation to the structure of the plant canopy. Differing mechanisms resulted in variations in the volume of percolate that was collected. Lower volumes of percolate were observed in herb-only monocultures of Leontdon hispidus, a species with a high water content. Tap-rooted species were seen to more effectively absorb soil moisture. The biodiversity support study focused on the study of Sedum species and Labiatae species, which suggested that mixed vegetation containing these species had a far greater likelihood of attracting wild bees to support pollination. Results of the studies indicated that green roof vegetation with greater structural and species diversity may provide different benefits than sedum-dominated roots. Further studies are needed to investigate the trade-offs between vegetation types, and green roof functions and performance in order to justify calls for a wider diversity of green roof types. 8 refs., 2 tabs., 1 fig.

  18. Aboveground vs. Belowground Carbon Stocks in African Tropical Lowland Rainforest: Drivers and Implications.

    Directory of Open Access Journals (Sweden)

    Sebastian Doetterl

    Full Text Available African tropical rainforests are one of the most important hotspots to look for changes in the upcoming decades when it comes to C storage and release. The focus of studying C dynamics in these systems lies traditionally on living aboveground biomass. Belowground soil organic carbon stocks have received little attention and estimates of the size, controls and distribution of soil organic carbon stocks are highly uncertain. In our study on lowland rainforest in the central Congo basin, we combine both an assessment of the aboveground C stock with an assessment of the belowground C stock and analyze the latter in terms of functional pools and controlling factors.Our study shows that despite similar vegetation, soil and climatic conditions, soil organic carbon stocks in an area with greater tree height (= larger aboveground carbon stock were only half compared to an area with lower tree height (= smaller aboveground carbon stock. This suggests that substantial variability in the aboveground vs. belowground C allocation strategy and/or C turnover in two similar tropical forest systems can lead to significant differences in total soil organic C content and C fractions with important consequences for the assessment of the total C stock of the system.We suggest nutrient limitation, especially potassium, as the driver for aboveground versus belowground C allocation. However, other drivers such as C turnover, tree functional traits or demographic considerations cannot be excluded. We argue that large and unaccounted variability in C stocks is to be expected in African tropical rain-forests. Currently, these differences in aboveground and belowground C stocks are not adequately verified and implemented mechanistically into Earth System Models. This will, hence, introduce additional uncertainty to models and predictions of the response of C storage of the Congo basin forest to climate change and its contribution to the terrestrial C budget.

  19. Aboveground vs. Belowground Carbon Stocks in African Tropical Lowland Rainforest: Drivers and Implications.

    Science.gov (United States)

    Doetterl, Sebastian; Kearsley, Elizabeth; Bauters, Marijn; Hufkens, Koen; Lisingo, Janvier; Baert, Geert; Verbeeck, Hans; Boeckx, Pascal

    2015-01-01

    African tropical rainforests are one of the most important hotspots to look for changes in the upcoming decades when it comes to C storage and release. The focus of studying C dynamics in these systems lies traditionally on living aboveground biomass. Belowground soil organic carbon stocks have received little attention and estimates of the size, controls and distribution of soil organic carbon stocks are highly uncertain. In our study on lowland rainforest in the central Congo basin, we combine both an assessment of the aboveground C stock with an assessment of the belowground C stock and analyze the latter in terms of functional pools and controlling factors. Our study shows that despite similar vegetation, soil and climatic conditions, soil organic carbon stocks in an area with greater tree height (= larger aboveground carbon stock) were only half compared to an area with lower tree height (= smaller aboveground carbon stock). This suggests that substantial variability in the aboveground vs. belowground C allocation strategy and/or C turnover in two similar tropical forest systems can lead to significant differences in total soil organic C content and C fractions with important consequences for the assessment of the total C stock of the system. We suggest nutrient limitation, especially potassium, as the driver for aboveground versus belowground C allocation. However, other drivers such as C turnover, tree functional traits or demographic considerations cannot be excluded. We argue that large and unaccounted variability in C stocks is to be expected in African tropical rain-forests. Currently, these differences in aboveground and belowground C stocks are not adequately verified and implemented mechanistically into Earth System Models. This will, hence, introduce additional uncertainty to models and predictions of the response of C storage of the Congo basin forest to climate change and its contribution to the terrestrial C budget.

  20. TV borehole inspection and vacuum testing of roof strata

    International Nuclear Information System (INIS)

    Herget, G.

    1982-01-01

    To improve quality control of roof conditions, a program was carried out at Elliot Lake uranium mines in Ontario, Canada to test a portable TV camera system. This camera has a 29 mm diameter probe and is capable of identifying crack locations, crack width and approximate dip direction. The extent of fractures in the roof was checked with the aid of a vacuum system by placing packers in various boreholes and checking for communication. The removal of some rock bolts indicated an increase in fracture extent

  1. Modelling of green roof hydrological performance for urban drainage applications

    DEFF Research Database (Denmark)

    Locatelli, Luca; Mark, Ole; Mikkelsen, Peter Steen

    2014-01-01

    from 3 different extensive sedum roofs in Denmark. These data consist of high-resolution measurements of runoff, precipitation and atmospheric variables in the period 2010–2012. The hydrological response of green roofs was quantified based on statistical analysis of the results of a 22-year (1989...... return period. Annual runoff volumes were estimated to be 43–68% of the total precipitation. The peak time delay was found to greatly vary from 0 to more than 40 min depending on the type of event, and a general decrease in the time delay was observed for increasing rainfall intensities. Furthermore...

  2. Three-dimensional analysis of AP600 standard plant shield building roof

    International Nuclear Information System (INIS)

    Greimann, L.; Fanous, F.; Safar, S.; Khalil, A.; Bluhm, D.

    1999-01-01

    The AP600 passive containment vessel is surrounded by a concrete cylindrical shell covered with a truncated conical roof. This roof supports the passive containment cooling system (PCS) annular tank, shield plate and other nonstructural attachments. When the shield building is subjected to different loading combinations as defined in the Standard Review Plan (SRP), some of the sections in the shield building could experience forces in excess of their design values. This report summarized the three-dimensional finite element analysis that was conducted to review the adequacy of the proposed Westinghouse shield building design. The ANSYS finite element software was utilized to analyze the Shield Building Roof (SBR) under dead, snow, wind, thermal and seismic loadings. A three-dimensional model that included a portion of the shield building cylindrical shell, the conical roof and its attachments, the eccentricities at the cone-cylinder connection and at the compression ring and the PCS tank was developed. Mesh sensitivity studies were conducted to select appropriate element size in the cylinder, cone, near air intakes and in the vicinity of the eccentricities. Also, a study was carried out to correctly idealize the water-structure interaction in the PCS tank. Response spectrum analysis was used to calculate the internal forces at different sections in the SBR under Safe Shutdown Earthquake (SSE). Forty-nine structural modes and twenty sloshing modes were used. Two horizontal components of the SSE together with a vertical component were used. Modal stress resultants were combined taking into account the effects of closely spaced modes. The three earthquake directions were combined by the Square Root of the Sum Squares method. Two load combinations were studied. The load combination that included dead, snow, fluid, thermal and seismic loads was selected to be the most critical. Interaction diagrams for critical sections were developed and used to check the design

  3. EXTRACTION OF ROOF LINES FROM HIGH-RESOLUTION IMAGES BY A GROUPING METHOD

    Directory of Open Access Journals (Sweden)

    A. P. Dal Poz

    2016-06-01

    Full Text Available This paper proposes a method for extracting groups of straight lines that represent roof boundaries and roof ridgelines from highresolution aerial images using corresponding Airborne Laser Scanner (ALS roof polyhedrons as initial approximations. The proposed method is based on two main steps. First, straight lines that are candidates to represent roof ridgelines and roof boundaries of a building are extracted from the aerial image. Second, a group of straight lines that represent roof boundaries and roof ridgelines of a selected building is obtained through the optimization of a Markov Random Field (MRF-based energy function using the genetic algorithm optimization method. The formulation of this energy function considers several attributes, such as the proximity of the extracted straight lines to the corresponding projected ALS-derived roof polyhedron and the rectangularity (extracted straight lines that intersect at nearly 90°. Experimental results are presented and discussed in this paper.

  4. Study of wind forces on low-rise hip-roof building

    African Journals Online (AJOL)

    DR OKE

    to predict the wind loads and the flow patterns around the hip-roof building. .... various wind angle attack on the roof using CFD simulation. .... SIMPLE algorithm substitutes the flux correction equations into the discrete continuity equation to ...

  5. Field Testing Unvented Roofs with Asphalt Shingles in Cold and Hot-Humid Climates

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Kohta [Building Science Corporation, Westford, MA (United States); Lstiburek, Joseph W. [Building Science Corporation, Westford, MA (United States)

    2015-09-01

    Test houses with unvented roof assemblies were built to measure long-term moisture performance, in the Chicago area (5A) and the Houston area (2A). The Chicago-area test bed had seven experimental rafter bays, including a control vented compact roof, and six unvented roof variants with cellulose or fiberglass insulation. The interior was run at 50% RH. The Houston-area roof was an unvented attic insulated with spray-applied fiberglass. Most ridges and hips were built with a diffusion vent detail, capped with vapor permeable roof membrane. In contrast, the diffusion vent roofs had drier conditions at the roof peak in wintertime, but during the summer, RHs and MCs were higher than the unvented roof (albeit in the safe range).

  6. Impact of external longwave radiation on optimum insulation thickness in Tunisian building roofs based on a dynamic analytical model

    International Nuclear Information System (INIS)

    Daouas, Naouel

    2016-01-01

    Highlights: • An efficient tool is proposed for a rigorous energy analysis of building envelope. • The longwave radiation has an important impact on the energy requirements. • Optimum insulation thickness for roofs is rigorously determined in a cost analysis. • The present method is more accurate than the sol–air degree hours method. • The proposed model is applicable to the study of the efficiency of cool roofs. - Abstract: In Tunisia, the building sector is considered as a major issue of energy consumption. A special attention should be drawn to improve the thermal quality of the building envelope with real consideration of the Tunisian climate specificity. One of the most effective measures is the roof insulation. Therefore, the present study is concerned with the determination of the optimum insulation thickness and the resulting energy savings and payback period for two typical roof structures and two types of insulation materials. An efficient analytical dynamic model based on the Complex Finite Fourier Transform (CFFT) is proposed and validated in order to handle the nonlinear longwave radiation (LWR) exchange with the sky. This model provides a short computational time solution of the transient heat transfer through multilayer roofs, which could be a good alternative to some numerical methods. Both heating and cooling annual loads are rigorously estimated and used as inputs to a life-cycle cost analysis. Among the studied cases, the most economical one is the hollow terracotta-based roof insulated with rock wool, where the optimum insulation thickness is estimated to be 7.9 cm, with a payback period of 6.06 years and energy savings up to 58.06% of the cost of energy consumed without insulation. The impact of the LWR exchange component is quantified and the results show its important effect on the annual transmission loads and, consequently, on optimum insulation thickness. A sensitivity analysis shows the efficiency of cool roofs in the Tunisian

  7. The Effect of Medium Cultures on Water Use and Charactristic of Gazania Flowers (Gazania hybrida in Green Roof.

    Directory of Open Access Journals (Sweden)

    Tahereh Bahrami

    2017-09-01

    Full Text Available Introduction: Green roof is one of the newest phenomenons in architecture and urbanism that refers to the sustainable development concepts and it will be usable for increasing landscape design, improving quality of the environment and reduction in energy consumption. Ensure of existing adequate green landscape in urban areas and improving access to natural areas surrounding the cities can help to offset negative effects of urban life. The use of green roof technology in cities is one of advanced techniques of green landscape. A green or living roof is a roof of a building that is partially or completely covered with vegetation and a growing medium on top view of buildings. Green roof layers that considered for roof side consist of protection layer, drainage layer, growing medium and plant layer. Medium layer is the medium culture of green roof that plants are begins to grow in it. This space should enable to save enough minerals and water for conserve of green-roof plants. All kinds of plants can growth on the green roof, but there are some constraints in creative of design because of roots dimension, plant canopy, necessary volume of soil, suitable direction to light, good weather, weight of designed structures, budget of repairing and keeping. Materials and Methods: To evaluate the effect of some culture medium on water consumption, vegetative and reproductive traits of Gazania (Gazania hybrida in condition of green roof a factorial experiment was conducted based on a completely randomized design with nine treatments and three replications in 2014. Treatments were three levels of vermicompost (zero, 5%, and 10% and rice hull (zero, 7, and 14%. Seedlings of plants cultivated in the media mixture of coco peat 15%, perlite 15%, leaf 10%, manure 10%, and filed soil 50%. The container had 60 × 60 ×25 cm dimensions that placed on the roof of greenhouse building with four meters height. The measured traits was number, average, and diameter of

  8. The Effect of Medium Cultures on Water Use and Charactristic of Gazania Flowers (Gazania hybrida in Green Roof.

    Directory of Open Access Journals (Sweden)

    Tahereh Bahrami

    2017-02-01

    Full Text Available Introduction: Green roof is one of the newest phenomenons in architecture and urbanism that refers to the sustainable development concepts and it will be usable for increasing landscape design, improving quality of the environment and reduction in energy consumption. Ensure of existing adequate green landscape in urban areas and improving access to natural areas surrounding the cities can help to offset negative effects of urban life. The use of green roof technology in cities is one of advanced techniques of green landscape. A green or living roof is a roof of a building that is partially or completely covered with vegetation and a growing medium on top view of buildings. Green roof layers that considered for roof side consist of protection layer, drainage layer, growing medium and plant layer. Medium layer is the medium culture of green roof that plants are begins to grow in it. This space should enable to save enough minerals and water for conserve of green-roof plants. All kinds of plants can growth on the green roof, but there are some constraints in creative of design because of roots dimension, plant canopy, necessary volume of soil, suitable direction to light, good weather, weight of designed structures, budget of repairing and keeping. Materials and Methods: To evaluate the effect of some culture medium on water consumption, vegetative and reproductive traits of Gazania (Gazania hybrida in condition of green roof a factorial experiment was conducted based on a completely randomized design with nine treatments and three replications in 2014. Treatments were three levels of vermicompost (zero, 5%, and 10% and rice hull (zero, 7, and 14%. Seedlings of plants cultivated in the media mixture of coco peat 15%, perlite 15%, leaf 10%, manure 10%, and filed soil 50%. The container had 60 × 60 ×25 cm dimensions that placed on the roof of greenhouse building with four meters height. The measured traits was number, average, and diameter of

  9. Comparing grey water versus tap water and coal ash versus perlite on growth of two plant species on green roofs.

    Science.gov (United States)

    Agra, Har'el; Solodar, Ariel; Bawab, Omar; Levy, Shay; Kadas, Gyongyver J; Blaustein, Leon; Greenbaum, Noam

    2018-08-15

    Green roofs provide important ecosystem services in urban areas. In Mediterranean and other semi-arid climate regions, most perennial plants on green roofs need to be irrigated during the dry season. However, the use of freshwater in such regions is scarce. Therefore, the possibility of using grey water should be examined. Coal ash, produced primarily from the burning of coal in power plants, constitutes an environmental contaminant that should be disposed. One option is to use ash as a growing substrate for plants. Here, we compare the effects of irrigating with grey- versus tap-water and using ash versus perlite as growing substrates in green roofs. The study was conducted in northern Israel in a Mediterranean climate. The design was full factorial with three factors: water-type (grey or tap-water)×substrate-type (coal ash vs perlite)×plant species (Phyla nodiflora, Convolvulus mauritanicus or no-plant). The development of plants and the quality of drainage water along the season, as well as quality of the used substrates were monitored. Both plant species developed well under all the experimental conditions with no effect of water type or substrate type. Under all treatments, both plant species enhanced electrical conductivity (EC) and chemical oxygen demand (COD) of the drainage water. In the summer, EC and COD reached levels that are unacceptable in water and are intended to be reused for irrigation. We conclude that irrigating with grey water and using coal ash as a growth substrate can both be implemented in green roofs. The drainage from tap water as well as from grey water can be further used for irrigating the roof, but for that, COD and EC levels must be lowered by adding a sufficient amount of tap water before reusing. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. System for monitoring of green roof performance: use of weighing roof segment and non-invasive visualization

    Science.gov (United States)

    Jelinkova, Vladmira; Dohnal, Michal; Picek, Tomas; Sacha, Jan

    2015-04-01

    Understanding the performance of technogenic substrates for green roofs is a significant task in the framework of sustainable urban planning and water/energy management. The potential retention and detention of the anthropogenic, light weight soil systems and their temporal soil structure changes are of major importance. A green roof test segment was built to investigate the benefits of such anthropogenic systems. Adaptable low-cost system allows long-term monitoring of preferred characteristics. Temperature and water balance measurements complemented with meteorological observations and knowledge of physical properties of the substrates provide basis for detailed analysis of thermal and hydrological regime in green roof systems. The first results confirmed the benefits of green roof systems. The reduction of temperature fluctuations as well as rainfall runoff was significant. Depending on numerous factors such substrate material or vegetation cover the test green roof suppressed the roof temperature amplitude for the period analyzed. The ability to completely prevent (light rainfall events) or reduce and delay (medium and heavy rainfall events) the peak runoff was also analyzed. Special attention is being paid to the assessment of soil structural properties related to possible aggregation/disaggregation, root growth, weather conditions and associated structural changes using non-invasive imaging method. X-ray computed microtomography of undisturbed soil samples (taken from experimental segments) is used for description of pore space geometry, evaluation of surface to volume ratio, additionally for description of cracks and macropores as a product of soil flora and fauna activity. The information from computed tomography imaging will be used for numerical modeling of water flow in variable saturated porous media. The research was realized as a part of the University Centre for Energy Efficient Buildings supported by the EU and with financial support from the Czech

  11. Soiling of building envelope surfaces and its effect on solar reflectance – Part II: Development of an accelerated aging method for roofing materials

    Energy Technology Data Exchange (ETDEWEB)

    Sleiman, Mohamad [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kirchstetter, Thomas W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Berdahl, Paul [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gilbert, Haley E. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Quelen, Sarah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Marlot, Lea [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Preble, Chelsea V. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Chen, Sharon [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Montalbano, Amandine [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rosseler, Olivier [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Akbari, Hashem [Concordia Univ., Montreal (Canada); Levinson, Ronnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Destaillats, Hugo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-09

    Highly reflective roofs can decrease the energy required for building air conditioning, help mitigate the urban heat island effect, and slow global warming. However, these benefits are diminished by soiling and weathering processes that reduce the solar reflectance of most roofing materials. Soiling results from the deposition of atmospheric particulate matter and the growth of microorganisms, each of which absorb sunlight. Weathering of materials occurs with exposure to water, sunlight, and high temperatures. This study developed an accelerated aging method that incorporates features of soiling and weathering. The method sprays a calibrated aqueous soiling mixture of dust minerals, black carbon, humic acid, and salts onto preconditioned coupons of roofing materials, then subjects the soiled coupons to cycles of ultraviolet radiation, heat and water in a commercial weatherometer. Three soiling mixtures were optimized to reproduce the site-specific solar spectral reflectance features of roofing products exposed for 3 years in a hot and humid climate (Miami, Florida); a hot and dry climate (Phoenix, Arizona); and a polluted atmosphere in a temperate climate (Cleveland, Ohio). A fourth mixture was designed to reproduce the three-site average values of solar reflectance and thermal emittance attained after 3 years of natural exposure, which the Cool Roof Rating Council (CRRC) uses to rate roofing products sold in the US. This accelerated aging method was applied to 25 products₋single ply membranes, factory and field applied coatings, tiles, modified bitumen cap sheets, and asphalt shingles₋and reproduced in 3 days the CRRC's 3-year aged values of solar reflectance. In conclusion, this accelerated aging method can be used to speed the evaluation and rating of new cool roofing materials.

  12. Digging the New York City Skyline: soil fungal communities in green roofs and city parks.

    Directory of Open Access Journals (Sweden)

    Krista L McGuire

    Full Text Available In urban environments, green roofs provide a number of benefits, including decreased urban heat island effects and reduced energy costs for buildings. However, little research has been done on the non-plant biota associated with green roofs, which likely affect their functionality. For the current study, we evaluated whether or not green roofs planted with two native plant communities in New York City functioned as habitats for soil fungal communities, and compared fungal communities in green roof growing media to soil microbial composition in five city parks, including Central Park and the High Line. Ten replicate roofs were sampled one year after planting; three of these roofs were more intensively sampled and compared to nearby city parks. Using Illumina sequencing of the fungal ITS region we found that green roofs supported a diverse fungal community, with numerous taxa belonging to fungal groups capable of surviving in disturbed and polluted habitats. Across roofs, there was significant biogeographical clustering of fungal communities, indicating that community assembly of roof microbes across the greater New York City area is locally variable. Green roof fungal communities were compositionally distinct from city parks and only 54% of the green roof taxa were also found in the park soils. Phospholipid fatty acid analysis revealed that park soils had greater microbial biomass and higher bacterial to fungal ratios than green roof substrates. City park soils were also more enriched with heavy metals, had lower pH, and lower quantities of total bases (Ca, K, and Mg compared to green roof substrates. While fungal communities were compositionally distinct across green roofs, they did not differentiate by plant community. Together, these results suggest that fungi living in the growing medium of green roofs may be an underestimated component of these biotic systems functioning to support some of the valued ecological services of green roofs.

  13. Digging the New York City Skyline: soil fungal communities in green roofs and city parks.

    Science.gov (United States)

    McGuire, Krista L; Payne, Sara G; Palmer, Matthew I; Gillikin, Caitlyn M; Keefe, Dominique; Kim, Su Jin; Gedallovich, Seren M; Discenza, Julia; Rangamannar, Ramya; Koshner, Jennifer A; Massmann, Audrey L; Orazi, Giulia; Essene, Adam; Leff, Jonathan W; Fierer, Noah

    2013-01-01

    In urban environments, green roofs provide a number of benefits, including decreased urban heat island effects and reduced energy costs for buildings. However, little research has been done on the non-plant biota associated with green roofs, which likely affect their functionality. For the current study, we evaluated whether or not green roofs planted with two native plant communities in New York City functioned as habitats for soil fungal communities, and compared fungal communities in green roof growing media to soil microbial composition in five city parks, including Central Park and the High Line. Ten replicate roofs were sampled one year after planting; three of these roofs were more intensively sampled and compared to nearby city parks. Using Illumina sequencing of the fungal ITS region we found that green roofs supported a diverse fungal community, with numerous taxa belonging to fungal groups capable of surviving in disturbed and polluted habitats. Across roofs, there was significant biogeographical clustering of fungal communities, indicating that community assembly of roof microbes across the greater New York City area is locally variable. Green roof fungal communities were compositionally distinct from city parks and only 54% of the green roof taxa were also found in the park soils. Phospholipid fatty acid analysis revealed that park soils had greater microbial biomass and higher bacterial to fungal ratios than green roof substrates. City park soils were also more enriched with heavy metals, had lower pH, and lower quantities of total bases (Ca, K, and Mg) compared to green roof substrates. While fungal communities were compositionally distinct across green roofs, they did not differentiate by plant community. Together, these results suggest that fungi living in the growing medium of green roofs may be an underestimated component of these biotic systems functioning to support some of the valued ecological services of green roofs.

  14. Pemanfaatan Green Roof sebagai Media Filter Air Hujan di Kota Pontianak

    OpenAIRE

    Uria Karlena Sely Sakong

    2013-01-01

    Penelitian ini bertujuan untuk mempelajari pengaruh green roof terhadap kualitas air hujan di KotaPontianak. Pengaruh tersebut dipelajari dengan cara membandingkan antara kualitas air hujan yang melewatigreen roof dengan kualitas air yang tidak melewati green roof. Penelitian diawali dengan merancang danmembuat model green roof. Pengambilan sampel dilakukan sebanyak empat kali dan diuji di laboratoriumterhadap parameter pH, kekeruhan, Pb terlarut dan E.Col...

  15. Development of Clay Tile Coatings for Steep-Sloped Cool Roofs

    OpenAIRE

    Pisello, Anna; Cotana, Franco; Nicolini, Andrea; Brinchi, Lucia

    2013-01-01

    Most of the pitched roofs of existing buildings in Europe are covered by non-white roofing products, e.g., clay tiles. Typical, cost effective, cool roof solutions are not applicable to these buildings due to important constraints deriving from: (i) the owners of homes with roofs visible from the ground level; (ii) the regulation about the preservation of the historic architecture and the minimization of the visual environment impact, in particular in historic centers. In this perspective, th...

  16. Estimating forest and woodland aboveground biomass using active and passive remote sensing

    Science.gov (United States)

    Wu, Zhuoting; Dye, Dennis G.; Vogel, John M.; Middleton, Barry R.

    2016-01-01

    Aboveground biomass was estimated from active and passive remote sensing sources, including airborne lidar and Landsat-8 satellites, in an eastern Arizona (USA) study area comprised of forest and woodland ecosystems. Compared to field measurements, airborne lidar enabled direct estimation of individual tree height with a slope of 0.98 (R2 = 0.98). At the plot-level, lidar-derived height and intensity metrics provided the most robust estimate for aboveground biomass, producing dominant species-based aboveground models with errors ranging from 4 to 14Mg ha –1 across all woodland and forest species. Landsat-8 imagery produced dominant species-based aboveground biomass models with errors ranging from 10 to 28 Mg ha –1. Thus, airborne lidar allowed for estimates for fine-scale aboveground biomass mapping with low uncertainty, while Landsat-8 seems best suited for broader spatial scale products such as a national biomass essential climate variable (ECV) based on land cover types for the United States.

  17. Performance of an H-Darrieus in the skewed flow on a roof

    NARCIS (Netherlands)

    Mertens, S.; Kuik, van G.A.M.; Bussel, van G.J.W.

    2003-01-01

    Application of wind turbines on roofs of higher buildings is a subject of increasing interest. However, the wind conditions at the roof are complex and suitable wind turbines for this application are not yet developed. This paper addresses both issues: the wind conditions on the roof and the

  18. Wind loads on stand-off photovoltaic systems on pitched roofs

    NARCIS (Netherlands)

    Geurts, C.P.W.; Blackmore, P.A.

    2013-01-01

    Stand-off photovoltaic systems are a popular measure for retrofitting of existing pitched roofs. Panels are generally mounted parallel to the existing roof coverings, usually roofing tiles. Full scale and wind tunnel experiments have been performed to determine the net uplift loads on these systems,

  19. Solutions for Creating the Main Elements which Condition the Energy Consumption. Exterior Windows - Roof

    OpenAIRE

    Rubnicu, Alin

    2013-01-01

    The envelope of the building often has a complex geometry in which a multitude of different sub-assemblies can be identified. The envelope elements specific to roof areas can generally be of three types: walk and non-walk terrace roof as well as roof truss. The exterior joinery analysed is PVC type with four glass sheets.

  20. Evaluation of Green Roof Plants and Materials for Semi-Arid Climates

    Science.gov (United States)

    Abstract While green roof systems have proven to be highly effective in the evaporative cooling of buildings, reduction of roof top temperatures, protection of roof membranes from solar radiation degradation, reducing stormwater runoff, as well as beautification of the urban roo...

  1. Evaluation of Green Roof Water Quantity and Quality Performance in an Urban Climate

    Science.gov (United States)

    In this report we present an analysis of water benefits from an array of observed green roof and control (non-vegetated) roof project sites throughout NYC. The projects are located on a variety of building sites and represent a diverse set of available extensive green roof instal...

  2. Green Roofs: A Part of Green Infrastructure Strategy for Urban Areas

    Science.gov (United States)

    This is a presentation on the basics of green roof technology. The presentation highlights some of the recent ORD research projects on green roofs and provides insight for the end user as to the benefits for green roof technology. It provides links to currently available EPA rep...

  3. Who governs climate adaptation? Getting green roofs for stormwater retention off the ground

    NARCIS (Netherlands)

    Mees, H.L.P.; Driessen, P.P.J.; Runhaar, H.A.C.; Stamatelos, J.

    2013-01-01

    Green roofs are an innovative solution for urban stormwater management. This paper examines governance arrangements for green roofs as a ‘no-regrets’ climate adaptation measure in five cities. We analysed who governs green roofs, why and with what outcome. Our results show that hierarchical and

  4. 30 CFR 75.209 - Automated Temporary Roof Support (ATRS) systems.

    Science.gov (United States)

    2010-07-01

    ... of temporary support shall be used, as specified in the roof control plan, when— (1) Mining... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automated Temporary Roof Support (ATRS) systems... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Roof Support § 75.209...

  5. Urban reconciliation ecology: the potential of living roofs and walls.

    Science.gov (United States)

    Francis, Robert A; Lorimer, Jamie

    2011-06-01

    Reconciling human and non-human use of urban regions to support biological conservation represents a major challenge for the 21st century. The concept of reconciliation ecology, by which the anthropogenic environment may be modified to encourage non-human use and biodiversity preservation without compromising societal utilization, potentially represents an appropriate paradigm for urban conservation given the generally poor opportunities that exist for reserve establishment and ecological restoration in urban areas. Two habitat improvement techniques with great potential for reconciliation ecology in urban areas are the installation of living roofs and walls, which have been shown to support a range of taxa at local scales. This paper evaluates the reconciliation potential of living roofs and walls, in particular highlighting both ecological and societal limitations that need to be overcome for application at the landscape scale. We further consider that successful utilization of living roofs and walls for urban reconciliation ecology will rely heavily on the participation of urban citizens, and that a 'citizen science' model is needed to facilitate public participation and support and to create an evidence base to determine their effectiveness. Living roofs and walls are just one aspect of urban reconciliation ecology, but are particularly important 'bottom-up' techniques for improving urban biodiversity that can be performed directly by the citizenry. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Opportunities Green Roofs Can Offer Ghanaians and their Cities

    African Journals Online (AJOL)

    Lone Star College System

    2015-08-17

    Aug 17, 2015 ... rising faster than the daily maximum thereby decreasing the comfort index of city dwellers. Electricity ... also on the rise. Green roofs have ..... by 6%. In Central Florida in the U.S., Cummings et al. .... levels, provision of habitat for animals and plants and .... representation of the Mediterranean Sea. Bull.

  7. variability of rainwater quality due to roof characteristics

    African Journals Online (AJOL)

    water. Although, some people typically consume collected rainwater without any type of ... variability of rain water quality due to roof characteristics was investigated using ... coverage of potable water, water supply still lags ... in getting projects executed; lack of adequate ... deterioration and its effects on health are scarce.

  8. Green Roof Research through EPA's Regional Applied Research Effort - slides

    Science.gov (United States)

    The U.S. Environmental Protection Agency’s (EPA) Regional Applied Research Effort (RARE) allows the Regions of the EPA to choose research projects to be performed in partnership with EPA’s Office of Research and Development (ORD). Over the last decade, several green roof projects...

  9. Roofing: Workbook and Tests. First-Aid Training.

    Science.gov (United States)

    California State Dept. of Education, Sacramento. Bureau of Publications.

    This workbook on first aid is one of a series of nine individual units of instruction for roofing apprenticeship classes in California. The workbook covers 12 topics: introduction to first-aid practices; burns; skeletal injuries; spinal injuries; wounds, bleeding, and bruises; emergencies of the heart and blood circulation system; breathing and…

  10. Impedance deduction for vegetated roof surfaces : multiple geometry strategy

    NARCIS (Netherlands)

    Liu, C.; Hornikx, M.

    2016-01-01

    The transfer function method is an efficient procedure to deduce the ground surface impedance from short-range propagation measurements using one point source. It is able to provide a reasonable prediction of the surface impedance of a vegetated roof as well, and the characteristics of the vegetated

  11. Green roofs: A possible best management practice for enhancing ...

    African Journals Online (AJOL)

    City expansion typically erodes the natural ability of the locale to perform its ecosystem services. This paper discusses green roofs and their potential benefits for Ghanaian cities in terms of improving environmental quality. Limited analysis shows that daily minimum temperatures of cities like Accra are rising faster than the ...

  12. Fire-induced reradiation underneath photovoltaic arrays on flat roofs

    DEFF Research Database (Denmark)

    Kristensen, Jens Steemann; Merci, Bart; Jomaas, Grunde

    2018-01-01

    The impact of the reflection of fire-induced heat from a gas burner was studied experimentally to gain knowledge on the interaction between photovoltaic (PV) panels and a fire on flat roofs. The heat flux was measured in a total of eight points at the same level as the top of the gas burner. The ...

  13. 30 CFR 75.221 - Roof control plan information.

    Science.gov (United States)

    2010-07-01

    ... installation and spacing of supports for each method of mining used. (6) When an ATRS system is used, the... of pillar recovery, and the sequence of mining pillars. (9) A list of all support materials required... mining approaches within 150 feet of an outcrop. (12) A description of the roof and rib support necessary...

  14. Bioenergy production potential for aboveground biomass from a subtropical constructed wetland

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yi-Chung [Department of Forestry and Nature Conservation, Chinese Culture University, Taipei 11114 (China); Ko, Chun-Han [School of Forestry and Resource Conservation, National Taiwan University, Taipei 10617 (China); Bioenergy Research Center, National Taiwan University, Taipei 10617 (China); Chang, Fang-Chih [The Instrument Center, National Cheng Kung University, No.1, University Road, Tainan City 70101 (China); Chen, Pen-Yuan [Department of Landscape Architecture, National Chiayi University, Chiayi City 60004 (China); Liu, Tzu-Fen [School of Forestry and Resource Conservation, National Taiwan University, Taipei 10617 (China); Sheu, Yiong-Shing [Department of Water Quality Protection, Environmental Protection Administration, Executive Yuan, Taipei 10042 (China); Shih, Tzenge-Lien [Department of Chemistry, Tamkang University, Tamsui, Taipei 25137 (China); Teng, Chia-Ji [Environmental Protection Bureau, Taipei County Government, Taipei 22001 (China)

    2011-01-15

    Wetland biomass has potentials for bioenergy production and carbon sequestration. Planted with multiple species macrophytes to promote biodiversity, the 3.29 ha constructed wetland has been treated 4000 cubic meter per day (CMD) domestic wastewater and urban runoff. This study investigated the seasonal variations of aboveground biomass of the constructed wetland, from March 2007 to March 2008. The overall aboveground biomass was 16,737 kg and total carbon content 6185 kg at the peak of aboveground accumulation for the system emergent macrophyte at September 2007. Typhoon Korsa flood this constructed wetland at October 2007, however, significant recovery for emergent macrophyte was observed without human intervention. Endemic Ludwigia sp. recovered much faster, compared to previously dominated typha. Self-recovery ability of the macrophyte community after typhoon validated the feasibility of biomass harvesting. Incinerating of 80% biomass harvested of experimental area in a nearby incineration plant could produce 11,846 kWh for one month. (author)

  15. Glazed ceramic roof tiles: influence of surface features in the solar reflectance index; Influencia das caracteristicas da superficie no indice de refletancia solar de telhas ceramicas esmaltadas

    Energy Technology Data Exchange (ETDEWEB)

    Bortoli, Leitcia Silva de; Stapait, Camila Cristina; Marinoski, Deivis Luis; Fredel, Marcio Celso; Schabbach, Luciana M., E-mail: luciana.maccarini@ufsc.br [Universidade Federal de Santa Catarina (UFSC), Blumenau, SC (Brazil)

    2016-07-01

    In this study the influence of surface features of ceramic roof tiles in the solar reflectance index were evaluated. Two glazed ceramic roof tiles (type stoneware) with the same color (ivory) but with different appearance (matte and brilliant) were the focus of the analysis. The Solar Reflectance Index (SRI) of the roofs tiles were determined by the solar reflectance values (UV-VIS-NIR) and emittance, measured in laboratory. The samples showed SRI> 39 in accordance with LEED certification criteria (Leadership in Energy and Environmental Design), contributing to minimizing the Heat Island Effects. Although the matte roof tile shows a slightly higher SRI value (82) than the brilliant one (78), the results for the variables that composes the SRI value (reflectance and emittance) were very similar. Analysis of XRD, SEM and EDS performed on the surfaces of the two roofs indicated for the matte glaze the presence of microcrystals (with barium and zinc) that can contribute to the slightly highest value of SRI. The roughness (optical interferometer white light) and the brightness (brightness meter) of the samples were also measured. (author)

  16. Green roofs'retention performances in different climates

    Science.gov (United States)

    Viola, Francesco; Hellies, Matteo; Deidda, Roberto

    2017-04-01

    The ongoing process of global urbanization contributes to increasing stormwater runoff from impervious surfaces, threatening also water quality. Green roofs have been proved to be an innovative stormwater management tool to partially restore natural state, enhancing interception, infiltration and evapotranspiration fluxes. The amount of water that is retained within green roofs depends mainly on both soil properties and climate. The evaluation of the retained water is not trivial since it depends on the stochastic soil moisture dynamics. The aim of this work is to explore performances of green roofs, in terms of water retention, as a function of their depth considering different climate regimes. The role of climate in driving water retention has been mainly represented by rainfall and potential evapotranspiration dynamics, which are simulated by a simple conceptual weather generator at daily time scale. The model is able to describe seasonal (in-phase and counter-phase) and stationary behaviors of climatic forcings. Model parameters have been estimated on more than 20,000 historical time series retrieved worldwide. Exemplifying cases are discussed for five different climate scenarios, changing the amplitude and/or the phase of daily mean rainfall and evapotranspiration forcings. The first scenario represents stationary climates, in two other cases the daily mean rainfall or the potential evapotranspiration evolve sinusoidally. In the latter two cases, we simulated the in-phase or in counter-phase conditions. Stochastic forcings have been then used as an input to a simple conceptual hydrological model which simulate soil moisture dynamics, evapotranspiration fluxes, runoff and leakage from soil pack at daily time scale. For several combinations of annual rainfall and potential evapotranspiration, the analysis allowed assessing green roofs' retaining capabilities, at annual time scale. Provided abacus allows a first approximation of possible hydrological benefits

  17. Field Testing Unvented Roofs with Asphalt Shingles in Cold and Hot-Humid Climates

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Kohta [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lstiburek, Joseph W. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    Insulating roofs with dense-pack cellulose (instead of spray foam) has moisture risks, but is a lower cost approach. If moisture risks could be addressed, buildings could benefit from retrofit options, and the ability to bring HVAC systems within the conditioned space. Test houses with unvented roof assemblies were built to measure long-term moisture performance, in the Chicago area (5A) and the Houston area (2A). The Chicago-area test bed had seven experimental rafter bays, including a control vented compact roof, and six unvented roof variants with cellulose or fiberglass insulation. The interior was run at 50% RH. All roofs except the vented cathedral assembly experienced wood moisture contents and RH levels high enough to constitute failure. Disassembly at the end of the experiment showed that the unvented fiberglass roofs had wet sheathing and mold growth. In contrast, the cellulose roofs only had slight issues, such as rusted fasteners and sheathing grain raise. The Houston-area roof was an unvented attic insulated with spray-applied fiberglass. Most ridges and hips were built with a diffusion vent detail, capped with vapor permeable roof membrane. Some ridge sections were built as a conventional unvented roof, as a control. In the control unvented roofs, roof peak RHs reached high levels in the first winter; as exterior conditions warmed, RHs quickly fell. In contrast, the diffusion vent roofs had drier conditions at the roof peak in wintertime, but during the summer, RHs and MCs were higher than the unvented roof (albeit in the safe range).

  18. A Case Study of Effective Support Working Resistance and Roof Support Technology in Thick Seam Fully-Mechanized Face Mining with Hard Roof Conditions

    Directory of Open Access Journals (Sweden)

    Wei-bin Guo

    2017-06-01

    Full Text Available This paper presents the engineering geological properties and roof control tecnology for a thick coal seam fully-mechanized face mining with hard roof conditions (THC at the Jinhuagong Coal Mine (JCM, northwest China. The effective support working resistance and appropriate roof control technology are two critical factors for safe and productive mining in the THC. The load-estimate-method (LOEM is the effective method to determine the support working resistance for normal working conditions (the mining height less than 3.5 m. In order to prevent support crushing accidents from happening and to ensure the safety and high-efficiency in the THC, the LOEM was modified based on the structure of the overlying strata in the THC. The strata which can form the voussoir beam structure in normal working conditions and will break in the form of cantilever beam in the THC is defined as the key strata in the immediate roof. Therefore, the hanging length of the key strata in the immediate roof was considered in the LOEM. Furthermore, a method for calculating the hanging length of the key strata in the immediate roof and its influencing factors were proposed using cantilever beam theory analysis of the structure of the overlying strata. Moreover, in order to fully fill the goaf area with caving roof to reduce the energy accumulation of main roof movement, it was decided to apply destress blasting technique (DEBT at the JCM to control the large hanging length of the hard roof, so as to reduce the impact of the hard main roof movement on the working face. The key technique parameters of the roof caving borehole were also proposed. The obtained results demonstrated that the theoretical analysis is reasonable, and the chosen support type and the DEBT could meet the roof control requirements. The THC has achieved safety and high-efficiency mining.

  19. The relationship between species richness and aboveground biomass in a primary Pinus kesiya forest of Yunnan, southwestern China.

    Science.gov (United States)

    Li, Shuaifeng; Lang, Xuedong; Liu, Wande; Ou, Guanglong; Xu, Hui; Su, Jianrong

    2018-01-01

    The relationship between biodiversity and biomass is an essential element of the natural ecosystem functioning. Our research aims at assessing the effects of species richness on the aboveground biomass and the ecological driver of this relationship in a primary Pinus kesiya forest. We sampled 112 plots of the primary P. kesiya forests in Yunnan Province. The general linear model and the structural equation model were used to estimate relative effects of multivariate factors among aboveground biomass, species richness and the other explanatory variables, including climate moisture index, soil nutrient regime and stand age. We found a positive linear regression relationship between the species richness and aboveground biomass using ordinary least squares regressions. The species richness and soil nutrient regime had no direct significant effect on aboveground biomass. However, the climate moisture index and stand age had direct effects on aboveground biomass. The climate moisture index could be a better link to mediate the relationship between species richness and aboveground biomass. The species richness affected aboveground biomass which was mediated by the climate moisture index. Stand age had direct and indirect effects on aboveground biomass through the climate moisture index. Our results revealed that climate moisture index had a positive feedback in the relationship between species richness and aboveground biomass, which played an important role in a link between biodiversity maintenance and ecosystem functioning. Meanwhile, climate moisture index not only affected positively on aboveground biomass, but also indirectly through species richness. The information would be helpful in understanding the biodiversity-aboveground biomass relationship of a primary P. kesiya forest and for forest management.

  20. Tank design

    International Nuclear Information System (INIS)

    Earle, F.A.

    1992-01-01

    This paper reports that aboveground tanks can be designed with innovative changes to complement the environment. Tanks can be constructed to eliminate the vapor and odor emanating from their contents. Aboveground tanks are sometimes considered eyesores, and in some areas the landscaping has to be improved before they are tolerated. A more universal concern, however, is the vapor or odor that emanates from the tanks as a result of the materials being sorted. The assertive posture some segments of the public now take may eventually force legislatures to classify certain vapors as hazardous pollutants or simply health risks. In any case, responsibility will be leveled at the corporation and subsequent remedy could increase cost beyond preventive measures. The new approach to design and construction of aboveground tanks will forestall any panic which might be induced or perceived by environmentalists. Recently, actions by local authorities and complaining residents were sufficient to cause a corporation to curtail odorous emissions through a change in tank design. The tank design change eliminated the odor from fuel oil vapor thus removing the threat to the environment that the residents perceived. The design includes reinforcement to the tank structure and the addition of an adsorption section. This section allows the tanks to function without any limitation and their contents do not foul the environment. The vapor and odor control was completed successfully on 6,000,000 gallon capacity tanks

  1. Standard test method to determine the performance of tiled roofs to wind-driven rain

    Directory of Open Access Journals (Sweden)

    Sánchez de Rojas, M. I.

    2008-09-01

    Full Text Available The extent to which roof coverings can resist water penetration from the combination of wind and rain, commonly referred to as wind driven rain, is important for the design of roofs. A new project of European Standard prEN 15601 (1 specifies a method of test to determine the performance of the roof covering against wind driven rain. The combined action of wind and rain varies considerably with geographical location of a building and the associated differences in the rain and wind climate. Three windrain conditions and one deluge condition covering Northern Europe Coastal, Central Europe and Southern Europe are specified in the project standard, each subdivided into four wind-speeds and rainfall rates to be applied to the test. The project does not contain information on the level of acceptable performance.Para el diseño de los tejados es importante determinar el punto hasta el cual éstos pueden resistirse a la penetración de agua causada por la combinación de viento y lluvia. Un nuevo proyecto de Norma Europeo prEN 15601 (1 especifica un método de ensayo para determinar el comportamiento del tejado frente a la combinación de viento y lluvia. La acción combinada de viento y lluvia varía considerablemente con la situación geográfica de un edificio y las diferencias asociadas al clima de la lluvia y del viento. El proyecto de norma especifica las condiciones de viento y lluvia y una condición de diluvio para cada una de las tres zonas de Europa: Europa del Norte y Costera, Europa Central y Europa del Sur, cada una subdividida en cuatro condiciones de velocidades de viento y caudal de lluvia para ser aplicadas en los ensayos. El proyecto no contiene la información sobre condiciones aceptables.

  2. The Soil-Root Strength Performance of Alternanthera Ficoidea and Zoysia Japonica as Green Roof Vegetation

    Directory of Open Access Journals (Sweden)

    Abdullah Muhamad Firdaurs

    2017-01-01

    Full Text Available The rise of awareness on environmentalism has demanded that all parties involved in built environment to implement green technology in their construction projects. Great care must be taken when designing a green roof system including the selection of plants and appropriate substrates. This study was performed to investigate the soil-root composite strength of two types of green roof vegetation (A. Ficoidea and Z. Japonica at different growth periods for up to 6 months. Both plants were planted in six plastic plots (45 cm × 29 cm × 13 cm containing a mixture of perlite, vermiculite and organic soil. Every two months, a series of direct shear tests were conducted on a sample from each species to determine the root-soil shear strength. The tests continued until the 6th month. The average results showed that Z. Japonica had higher soil-root shear strength (49.1 kPa compared to A. Ficoidea after two months of growth. In the 4th month however, A. Ficoidea managed to surpass Z. Japonica (28.7 kPa versus 18.5 kPa in terms of shear strength. However, their average peak shear strength decreased sharply compared to the previous month. Lastly, in six months, A. Ficoidea sustained a higher average peak soil shear strength (56.5 kPa compared to Z. Japonica (14.3 kPa. Therefore, it can be concluded that A. Ficoidea may offer a better soil reinforcement than Z. japonica and thus it could potentially be a good choice of green roof vegetation.

  3. Analysis of technical-economic requirements for the construction of a solar power plant on the roof of the business building of the Electrical Engineering Institute 'Nikola Tesla'

    Directory of Open Access Journals (Sweden)

    Grbić Maja

    2014-01-01

    Full Text Available This paper presents an analysis of the technical-economic requirements for the construction of a solar power plant on the roof of the business building of the Electrical Engineering Institute 'Nikola Tesla' in Belgrade. Calculation of solar irradiation is performed and the conceptual design of the disposition of solar panels on the roof of the building is shown as well as their connections to the inverters. Conditions for connecting the plant to the distribution network are checked and an economic analysis of the project is performed.

  4. Open cup nests evolved from roofed nests in the early passerines.

    Science.gov (United States)

    Price, J Jordan; Griffith, Simon C

    2017-02-08

    The architectural diversity of nests in the passerine birds (order Passeriformes) is thought to have played an important role in the adaptive radiation of this group, which now comprises more than half of avian species and occupies nearly all terrestrial ecosystems. Here, we present an extensive survey and ancestral state reconstruction of nest design across the passerines, focusing on early Australian lineages and including members of nearly all passerine families worldwide. Most passerines build open cup-shaped nests, whereas a minority build more elaborate domed structures with roofs. We provide strong evidence that, despite their relative rarity today, domed nests were constructed by the common ancestor of all modern passerines. Open cup nests evolved from enclosed domes at least four times independently during early passerine evolution, at least three of which occurred on the Australian continent, yielding several primarily cup-nesting clades that are now widespread and numerically dominant among passerines. Our results show that the ubiquitous and relatively simple cup-shaped nests of many birds today evolved multiple times convergently, suggesting adaptive benefits over earlier roofed designs. © 2017 The Author(s).

  5. Load test of the 3701U Building roof deck and support structure

    International Nuclear Information System (INIS)

    McCoy, R.M.

    1994-01-01

    The 3701U Building roof area was load tested according to the approved load-test procedure. The 3701U Building is located in the 300 Area of the Hanford Site and has the following characteristics: Roof deck--metal decking supported by steel purlins; Roof membrane--tar and gravel; Roof slope--flat (<10 deg); and Roof elevation--height of about 12.5 ft. The 3701U Building was visited in August 1992 for a visual inspection, but because of insulation an inspection could not be performed. The building was revisited in March 1994 for the purpose of writing this test report. Because the roof could not be inspected, a test was determined to be the best way to qualify the roof for personnel access. The test procedure called for the use of a remotely-controlled robot. The conclusions are that the roof has been qualified for 500-lb total roof load and that the ''No Roof Access'' signs can be changed to ''Roof Access Restricted'' signs

  6. Bio deterioration behaviour in different colour roofing tiles (red and straw coloured)

    International Nuclear Information System (INIS)

    Guzulla, M. F.; Sanchez, E.; Gonzalez, J. M.; Orduna, M.

    2014-01-01

    Bio colonization of building materials is a critical problem for the durability of constructions. Industrial experience shows that straw coloured roofing tiles are more prone to colonization than red roofing tiles, even having similar characteristics. The aim of this work is to explain the difference of bio colonization between different colour roofing tiles. The chemical composition of the surface of straw coloured and red roofing tiles, the phase composition and the microstructure of the roofing tiles were determined by WD-XRF, XRD and SEM-EDX, respectively. The pore size distribution was carried out by Hg porosimetry. The solubility was studied by determining the soluble salts (Ca, Mg, Na, K, Cl and SO 4 2-) by ICP-OES and ionic chromatography. Roofing tile bio receptivity was evaluated by determining fluorescence intensity using a pulse amplitude- modulated (PAM) fluoro meter, and cyanobacteria Oscillator sp. The results obtained show higher concentration of calcium and sulphur in straw coloured roofing tiles surface, and higher solubility than red roofing tiles. Moreover, according to the results obtained in bio receptivity assays, straw coloured roofing tiles are more prone to colonization than red roofing tiles, so, there is a relationship between surface properties of roofing tiles and bio colonization, as it is observed in industrial products. (Author)

  7. Assessment of green roof systems in terms of water and energy balance

    Directory of Open Access Journals (Sweden)

    Mert Ekşi

    2016-01-01

    Full Text Available Green roofs concept term is used for extensive green roofs which are planted with herbaceous plants that can be adapted into changeable environmental conditions on a shallow substrate layer, require minimal maintenance, installed for their benefits to building and urban scale. Main objective of this study is to determine the characteristics of a green roof such as thermal insulation, water holding capacity, runoff characteristics, plant growth and its interaction with environmental factors in Istanbul climate conditions by performing comparative measurements. In this study, a research site (IU Green Roof Research Station was founded to assess water and energy balance of green roofs. Thus, a typical green roof was evaluated in terms of water and energy balance and its interaction with the building and city was determined. energy efficiency of green roof system was 77% higher than reference roof. Temperature fluctuations on green roof section of the roof were 79% lower. In addition, green roof retained 12,8% - 100% of precipitation and delayed runoff up to 23 hours depending on water content of substrate.

  8. Load test of the 277W Building high bay roof deck and support structure

    International Nuclear Information System (INIS)

    McCoy, R.M.

    1994-01-01

    The 277W Building high bay roof area was load tested according to the approved load-test procedure, WHC-SD-GN-TP-30015, Revision 1. The 277W Building is located in the 200 West Area of the Hanford Site and has the following characteristics: roof deck -- wood decking supported by 4 x 14 timber purlins; roof membrane -- tar and gravel; roof slope -- flat (<10 deg); and roof elevation -- maximum height of about 63 ft. The 227W Building was visited in March 1994 for a visual inspection. During this inspection, cracked areas were visible in the decking, but it was not possible to determine whether these cracks extended completely through the decking, which is 2-in. thick. The building was revisited in March 1994 for the purpose of writing this test report. Because the roof requires personnel access, a test was determined to be the best way to qualify the roof. The conclusions are that the roof has been qualified for 500-lb total roof load and that the ''No Roof Access'' signs can be changed to ''Roof Access Restricted'' signs

  9. A Review of Methods for the Manufacture of Residential Roofing Materials

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hashem; Levinson, Ronnen; Berdahl, Paul

    2003-06-01

    Shingles, tiles, and metal products comprise over 80% (by roof area) of the California roofing market (54-58% fiberglass shingle, 8-10% concrete tile, 8-10% clay tile, 7% metal, 3% wood shake, and 3% slate). In climates with significant demand for cooling energy, increasing roof solar reflectance reduces energy consumption in mechanically cooled buildings, and improves occupant comfort in non-conditioned buildings. This report examines methods for manufacturing fiberglass shingles, concrete tiles, clay tiles, and metal roofing. The report also discusses innovative methods for increasing the solar reflectance of these roofing materials. We have focused on these four roofing products because they are typically colored with pigmented coatings or additives. A better understanding of the current practices for manufacturing colored roofing materials would allow us to develop cool colored materials creatively and more effectively.

  10. Monitoring of the Green Roofs Installation in Brno-City District, Czech Republic

    Science.gov (United States)

    Rebrova, Tatiana; Beckovsky, David; Selnik, Petr

    2017-12-01

    In spite of the rapidly growing interest to the green roofs, there is insufficient information about their local quantities and areas in Czech Republic as well as in Central Europe. There is a lack of technical information that leads to the further development, application and environmental contribution of green roofs under local climatic conditions. The purpose of the research is to follow the tendency of how the process of green roofs’ popularization is performed in the Czech Republic and to determine basic parameters of the installed green roofs. These parameters include total quantity, area and the most common roof vegetation type (extensive or intensive); how many green roofs were installed over the last years and as a result, how the proportion of the green roofs to the conventional ones is changing. For initial evaluation Brno-City District was chosen as the next stage of university environmental project EnviHUT following the genesis of green roofs under local weather conditions.

  11. Adsorption of *sp134*Cs onto two different types of roof materials

    International Nuclear Information System (INIS)

    Quenild, C.; Tveten, U.

    1983-01-01

    The report relates to a subproject under a Nordic project called ''Large reactor accidents - consequences and mitigating actions''. Natural decontamination of two types of roof material, typical of Norwegian and Swedish buildings, was examined. The roofs were contaminated with *sp134*Cs. After two days with 7 mm precipitation, the remaining activity on the tar-paper roof was 97% and on the steel roof 29%. After 8 months the remaining activity was 61% on the tar-paper roof and 22% on the steel roof. In spring *sp134*Cs was spread upon an 8 cm thick layer of fresh snow on an additional tar-paper roof. After 3 montsh and 191 mm precipitation the remaining activity was 59%. All results are based upon *sp134*Cs in collected run-off water.(Auth.)

  12. Experimental research on coalbed gas drainage effect and economy of long directional borehole in roof

    Science.gov (United States)

    Yang, Huiming; Hu, Liangping

    2017-05-01

    In order to study the coalbed gas drainage effect and economy of long directional roof borehole, 2 boreholes were laid out in Xinji No. 2 mine to analyze its gas drainage and investment costs comparing with high position roof borehole and high position roof roadway. The result indicates that the long directional roof borehole save investment by 44.8% and shorten the construction period by 30%, comparing with high position roof roadway for controlling gas in the working face. Investment slightly less and shorten the construction period by 47.5%, comparing with the roof high position borehole. Therefore, the method of the long directional roof borehole to drain coalbed gas in working face is the most cost-effective.

  13. Local above-ground persistence of vascular plants : Life-history trade-offs and environmental constraints

    NARCIS (Netherlands)

    Ozinga, Wim A.; Hennekens, Stephan M.; Schaminee, Joop H. J.; Smits, Nina A. C.; Bekker, Renee M.; Roemermann, Christine; Klimes, Leos; Bakker, Jan P.; van Groenendael, Jan M.

    Questions: 1. Which plant traits and habitat characteristics best explain local above-ground persistence of vascular plant species and 2. Is there a trade-off between local above-ground persistence and the ability for seed dispersal and below-ground persistence in the soil seed bank? Locations: 845

  14. Above-ground biomass investments and light interception of tropical forest trees and lianas early in succession

    NARCIS (Netherlands)

    Selaya, N.G.; Anten, N.P.R.; Oomen, R.J.; Matthies, M.; Werger, M.J.A.

    2007-01-01

    Background and Aims Crown structure and above-ground biomass investment was studied in relation to light interception of trees and lianas growing in a 6-month-old regenerating forest. Methods The vertical distribution of total above-ground biomass, height, diameter, stem density, leaf angles and

  15. Airborne laser scanner-assisted estimation of aboveground biomass change in a temperate oak-pine forest

    Science.gov (United States)

    Nicholas S. Skowronski; Kenneth L. Clark; Michael Gallagher; Richard A. Birdsey; John L. Hom

    2014-01-01

    We estimated aboveground tree biomass and change in aboveground tree biomass using repeated airborne laser scanner (ALS) acquisitions and temporally coincident ground observations of forest biomass, for a relatively undisturbed period (2004-2007; ∇07-04), a contrasting period of disturbance (2007-2009; ∇09-07...

  16. Effects of above-ground plant species composition and diversity on the diversity of soil-borne microorganisms

    NARCIS (Netherlands)

    Kowalchuk, G.A.; Buma, D.S; De Boer, W.; Klinkhamer, P.G.L.; Van Veen, J.A.

    2002-01-01

    A coupling of above-ground plant diversity and below-ground microbial diversity has been implied in studies dedicated to assessing the role of macrophyte diversity on the stability, resilience, and functioning of ecosystems. Indeed, above-ground plant communities have long been assumed to drive

  17. 49 CFR 571.118 - Standard No. 118; Power-operated window, partition, and roof panel systems.

    Science.gov (United States)

    2010-10-01

    ...-operated window, partition, and roof panel systems. S1. Purpose and scope. This standard specifies requirements for power operated window, partition, and roof panel systems to minimize the likelihood of death... Figure 2. Power operated roof panel systems mean moveable panels in the vehicle roof which close by...

  18. Thermal performances of ETFE cushion roof integrated amorphous silicon photovoltaic

    International Nuclear Information System (INIS)

    Hu, Jianhui; Chen, Wujun; Qiu, Zhenyu; Zhao, Bing; Zhou, Jinyu; Qu, Yegao

    2015-01-01

    Highlights: • Thermal performances of a three layer ETFE cushion integrated a-Si PV is evaluated. • Temperature of a-Si PV obviously affects temperature field and temperature boundary. • The maximum temperature difference of 3.4 K between measured and numerical results. • Main transport mechanisms in upper and lower chambers are convection and conduction. • Heat transfer coefficients of this roof are less than those of other ETFE cushion roofs. - Abstract: Thermal performances of the ETFE cushion roof integrated amorphous silicon photovoltaic (a-Si PV) are essential to estimate building performances, such as temperature distribution and heat transfer coefficient. To investigate these thermal performances, an experimental mock-up composed of a-Si PV and a three-layer ETFE cushion roof was built and the experiment was carried out under summer sunny condition. Meanwhile, numerical model with real boundary conditions was performed in this paper. The experimental results show that the temperature sequence of the three layers was the middle, top and bottom layer and that the PV temperature caused by solar irradiance was 353.8 K. This gives evidence that the PV has a significant effect on the temperature distribution. The experimental temperature was in good agreement with the corresponding location of the numerical temperature since the maximum temperature difference was only 3.4 K. Therefore, the numerical results were justified and then used to analyze the airflow characteristics and calculate the thermal performances. For the airflow characteristics, it is found that the temperature distribution was not uniform and the main transport mechanisms in the upper and lower chambers formed by the three layers were the convection and conduction, respectively. For the thermal performances, the surface convective heat transfer coefficients were obtained, which have validated that thermal performances of the three-layer ETFE cushion integrated a-Si PV are better than

  19. Soft Roof Failure Mechanism and Supporting Method for Gob-Side Entry Retaining

    Directory of Open Access Journals (Sweden)

    Hongyun Yang

    2015-10-01

    Full Text Available To study the soft roof failure mechanism and the supporting method for a gateway in a gently inclined coal seam with a dip angle of 16° kept for gob-side entry retaining, and through the methodology of field investigation and numerical and analytical modeling, this paper analyzed the stress evolution law of roof strata at the working face end and determined that the sharp horizontal stress unloading phenomenon along the coal wall side did not appear after the working face advanced. Conversely, the horizontal stress along the gob side instantly decreased and the tensile stress produced, and the vertical stress in the central part of the roof had a higher reduction magnitude as well. An in-depth study indicates that the soft roof of the working face end subsided and seriously separated due to the effect of the front abutment pressure and the roof hanging length above the gob line, as well as certain other factors, including the rapid unloading of the lateral stress, tension and shear on the lower roof rock layer and dynamic disturbance. Those influencing factors also led to rapid crack propagation on a large scale and serious fracturing in the soft roof of the working face end. However, in the gob stress stabilized zone, the soft roof in the gob-side entry retaining has a shearing failure along the filling wall inside affected by the overburden pressure, rock bulking pressure, and roof gravity. To maintain the roof integrity, decrease the roof deformation, and enable the control of the working face end soft roof and the stabilization of the gob-side entry retaining roof, this study suggests that the preferred bolt installation angle for the soft roof situation is 70° based on the rock bolt extrusion strengthening theory.

  20. The impact of green roof ageing on substrate characteristics and hydrological performance

    Science.gov (United States)

    De-Ville, Simon; Menon, Manoj; Jia, Xiaodong; Reed, George; Stovin, Virginia

    2017-04-01

    Green roofs contribute to stormwater management through the retention of rainfall and the detention of runoff. However, there is very limited knowledge concerning the evolution of green roof hydrological performance with system age. This study presents a non-invasive technique which allows for repeatable determination of key substrate characteristics over time, and evaluates the impact of observed substrate changes on hydrological performance. The physical properties of 12 green roof substrate cores have been evaluated using non-invasive X-ray microtomography (XMT) imaging. The cores comprised three replicates of two contrasting substrate types at two different ages: unused virgin samples; and 5-year-old samples from existing green roof test beds. Whilst significant structural differences (density, pore and particle sizes, tortuosity) between virgin and aged samples of a crushed brick substrate were observed, these differences did not significantly affect hydrological characteristics (maximum water holding capacity and saturated hydraulic conductivity). A contrasting substrate based upon a light expanded clay aggregate experienced increases in the number of fine particles and pores over time, which led to increases in maximum water holding capacity of 7%. In both substrates, the saturated hydraulic conductivity estimated from the XMT images was lower in aged compared with virgin samples. Comparisons between physically-derived and XMT-derived substrate hydrological properties showed that similar values and trends in the data were identified, confirming the suitability of the non-invasive XMT technique for monitoring changes in engineered substrates over time. The observed effects of ageing on hydrological performance were modelled as two distinct hydrological processes, retention and detention. Retention performance was determined via a moisture-flux model using physically-derived values of virgin and aged maximum water holding capacity. Increased water holding