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. Design methodology for innovative roofs

    NARCIS (Netherlands)

    Quanjel, E.M.C.J.; Zeiler, W.; Trum, H.M.G.J.

    2006-01-01

    Traditional roofs have primary, passive, functions such as protection against rain, wind, snow etc.. Nowadays, roofs are increasingly used as preferred location for additional functions such as photovoltaic systems, roof lights and safety devices. New approaches, on designing as well as assembling t

  4. 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.

  5. On the Design of Suspended Roofs with Paraboloidal Surfaces

    Directory of Open Access Journals (Sweden)

    N. Ungureanu

    2006-01-01

    Full Text Available Some considerations concerning the design of the paraboloidal suspended roofs are made. The main geometric aspects are first time presented. For the roofs we propose, as pattern, the equivalent continuum membranes, and the efforts in the cable are determined by using the membrane efforts and their equations. Two examples are analyzed: elliptic paraboloide and hyperbolic paraboloide, with horizontal projection under the form of an ellipse.

  6. A method for the design of longwall gateroad roof support

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, W. [Geowork Engineering, Emerald, Qld. (Australia)

    2009-06-15

    A longwall gateroad roof support design method for roadway development and panel extraction is demonstrated. It is a hybrid numerical and empirical method called gateroad roof support model (GRSM), where specification of roof support comes from charts or equations. GRSM defines suggested roof support densities by linking a rock-mass classification with an index of mining-induced stress, using a large empirical database of Bowen Basin mining experience. Inherent in the development of GRSM is a rock-mass classification scheme applicable to coal measure strata. Coal mine roof rating (CMRR) is an established and robust coal industry standard, while the geological strength index (GSI) may also be used to determine rock-mass geomechanical properties. An elastic three-dimensional numerical model was established to calculate an index of mining induced stress, for both roadway development and longwall retreat. Equations to calculate stress index derived from the numerical modelling have been developed. An industry standard method of quantifying roof support is adopted as a base template (GRSUP). The statistical analyses indicated that an improved quantification of installed support can be gained by simple modifications to the standard formulation of GRSUP. The position of the mathematically determined stable/failed boundary in the design charts can be changed depending on design criteria and specified risk.

  7. Integral design methodology for collaborative design of sustainable roofs

    NARCIS (Netherlands)

    Quanjel, E.M.C.J.

    2006-01-01

    Normally the roof is the part of building which gets minimal attention to use for integration with the comfort system of the building. This is striking, as the roof is an important possible building component for containing sustainable energy systems. The sustainable energy possible options are ofte

  8. Temperature reduction in attic and ceiling via insulation of several passive roof designs

    Energy Technology Data Exchange (ETDEWEB)

    Ong, K.S., E-mail: Ong.Kok.Seng@eng.monash.edu.m [Monash University Sunway Campus, Jalan Lagoon Selatan, 46150 Bandar Sunway (Malaysia)

    2011-06-15

    Research highlights: {yields} Six passive roof designs were tested simultaneously outdoors. {yields} Roof, attic and ceiling temperatures were determined. {yields} Solar collector roof design provided the coolest attic and ceiling. {yields} Placing insulation under roof is preferred to above ceiling. -- Abstract: High ambient temperatures coupled with high humidity lead to uncomfortable conditions that are non-conducive for human comfort and productivity. Heat transmission through the roof could be reduced by providing insulation in the attic under the roof or above the ceiling. A roof solar collector could provide both ventilation and cooling in the attic. Several laboratory sized units of passive roof designs were constructed and tested side-by-side under outdoor conditions to obtain temperature data of the roof, attic and ceiling in order to compare their performances.

  9. 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.

  10. Reviewing Green roof design approaches: Case study of residential buildings

    OpenAIRE

    Özarısoy, Bertuğ

    2013-01-01

    ABSTRACT: High density of the residential areas and steep land value in the cities have driven people to maximize liveable and productive spaces in urban settings. This includes the reinvention of roof functions extending merely as a protection from the elements to a platform of housing green building technologies such as green roofs. Increased interest in green roofs have led to advances in technology. An entire industry has sprung up which specializes in lightweight growing materials, ro...

  11. 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 co

  12. Parametric design of the Vela roof: A case study on performance oriented exploration of design alternatives

    NARCIS (Netherlands)

    Turrin, M.; Stouffs, R.M.F.; Sariyildiz, I.S.

    2010-01-01

    The paper presents a case study, in which parametric modeling has been used to explore the geometrical design alternatives of a large span roof. Explorative criteria are oriented to the use of on site energy resources, with specific focus on the mitigation of summer discomfort. After broadly

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

    OpenAIRE

    Manoj Chopra; Martin Wanielista; Mike Hardin

    2012-01-01

    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...

  14. ACARP scholarship - a method for the design of longwall gateroad roof support

    Energy Technology Data Exchange (ETDEWEB)

    Bill Lawrence [Geowork Engineering (Australia)

    2009-03-15

    A longwall gateroad roof support design method for roadway development and panel extraction is demonstrated. It is a hybrid numerical and empirical method called Gateroad Roof Support Model (GRSM), where specification of roof support comes from charts or equations. GRSM defines suggested roof support densities by linking a rock-mass classification with an index of mining induced stress, using a large empirical database of Bowen Basin mining experience. An elastic three-dimensional numerical model was established to calculate an index of mining induced stress, for both roadway development and longwall retreat. Installed roof support must be characterised and quantified, both to establish the empirical database and to specify suggested support densities and patterns for a design. An industry standard method of quantifying roof support is adopted as a base template (GRSUP). A statistical analyses indicated that an improved quantification of installed support can be gained by simple modifications to the standard formulation of GRSUP. General design charts were constructed for roadway development and longwall retreat based on logistic regression analyses, which considered three independent variables; roof classification, stress index, and various modifications to GRSUP. Initial stable-failure boundaries were determined mathematically using an optimal statistical solution from the logistic regression. The position of the stable/failed boundary can be changed depending on design criteria and specified risk. Considering the probability of a stable outcome, more appropriate and conservative stable-failure boundary can be readily defined.

  15. 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.

  16. 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....

  17. Discussion on the design of roof greening%屋顶绿化设计探讨

    Institute of Scientific and Technical Information of China (English)

    和晓艳

    2012-01-01

    This paper researched the design of roof greening,explained that the roof greening was the effective method to use city roof space,pointed out its key design was how to reduce the roof load,plants plant select etc..In the design should follow the design principles.Point out the design elements used in land greening could also be used in roof greening,the roof greening design elements had no restrictions.%对屋顶绿化的设计进行了研究,说明屋顶绿化是利用城市屋面空间的有效方法,指出其设计关键在于如何减轻屋顶荷载,植物种植选择等,在设计时要遵循设计原则,提出地面绿化中可以使用的设计要素也可以用于屋顶绿化,屋顶绿化设计要素种类没有限制。

  18. 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.

  19. 屋顶花园的设计%The Design of Roof Garden

    Institute of Scientific and Technical Information of China (English)

    郭帅

    2014-01-01

    The history of roof garden can trace back to till around 2000 B.C.. Our country from just start studying roof garden and roof from 60's green turn of construct a technique. The programming of roof garden designs, making natural ecosystem environment and the city total ecosystem environment of roof merge into an integral whole, the city civilization always continues to blend with living environment culture. The space layout of roof garden is accepted a heavy check and supervision by restriction and building structure of constructing the proper flat surface, building a park with ground to compare, its design since complications again relate to related work to grow of be in conjunction with, building design, building structure, building structure and water give or get an electric shock etc. Work's growing the coordination of [with] match is the key of [with] roof garden success or failure. From this, the programming design of roof garden is greatly a difficulty and limits many park programming a design item.%屋顶花园的历史可以追溯到公元前2000年左右。我国自60年代起,才开始研究屋顶花园和屋顶绿化的建造技术。屋顶花园的规划设计,使屋顶的自然生态环境与城市总体生态环境融为一体,城市文明的延续与生活环境文化融合。屋顶花园的空间布局受到建筑固有平面的限制和建筑结构承重的制约,与露地造园相比,其设计既复杂又关系到相关工种的协同,建筑设计、建筑构造、建筑结构和水电等工种配合的协调是屋顶花园成败的关键。由此可见,屋顶花园的规划设计是一项难度大、限制多的园林规划设计项目。

  20. 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

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

    DEFF Research Database (Denmark)

    Parigi, Dario

    2015-01-01

    framework is the Performance Aided/Assisted Design (PAD) approach, which focuses on the increasing range of available performance analysis, optimization strategies, interfaces, tools, methodologies, and their ability to foster creativity by increasing designers' understanding of the complex network...... for creative work in architectural design ....

  2. 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.

  3. 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...

  4. 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 ...

  5. Investigating Appropriate Sampling Design for Estimating Above-Ground Biomass in Bruneian Lowland Mixed Dipterocarp Forest

    Science.gov (United States)

    Lee, S.; Lee, D.; Abu Salim, K.; Yun, H. M.; Han, S.; Lee, W. K.; Davies, S. J.; Son, Y.

    2014-12-01

    Mixed tropical forest structure is highly heterogeneous unlike plantation or mixed temperate forest structure, and therefore, different sampling approaches are required. However, the appropriate sampling design for estimating the above-ground biomass (AGB) in Bruneian lowland mixed dipterocarp forest (MDF) has not yet been fully clarified. The aim of this study was to provide supportive information in sampling design for Bruneian forest carbon inventory. The study site was located at Kuala Belalong lowland MDF, which is part of the Ulu Tembulong National Park, Brunei Darussalam. Six 60 m × 60 m quadrats were established, separated by a distance of approximately 100 m and each was subdivided into quadrats of 10 m × 10 m, at an elevation between 200 and 300 m above sea level. At each plot all free-standing trees with diameter at breast height (dbh) ≥ 1 cm were measured. The AGB for all trees with dbh ≥ 10 cm was estimated by allometric models. In order to analyze changes in the diameter-dependent parameters used for estimating the AGB, different quadrat areas, ranging from 10 m × 10 m to 60 m × 60 m, were used across the study area, starting at the South-West end and moving towards the North-East end. The derived result was as follows: (a) Big trees (dbh ≥ 70 cm) with sparse distribution have remarkable contribution to the total AGB in Bruneian lowland MDF, and therefore, special consideration is required when estimating the AGB of big trees. Stem number of trees with dbh ≥ 70 cm comprised only 2.7% of all trees with dbh ≥ 10 cm, but 38.5% of the total AGB. (b) For estimating the AGB of big trees at the given acceptable limit of precision (p), it is more efficient to use large quadrats than to use small quadrats, because the total sampling area decreases with the former. Our result showed that 239 20 m × 20 m quadrats (9.6 ha in total) were required, while 15 60 m × 60 m quadrats (5.4 ha in total) were required when estimating the AGB of the trees

  6. 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.

  7. 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…

  8. 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…

  9. The case for using a sacrificial layer of absorbent insulation in the design of flat and low-sloped roofing

    Science.gov (United States)

    Stockton, Gregory R.

    2013-05-01

    Beginning about twenty-five years ago, there was a marked increase in the number of single-ply membrane roof designs used to cover and waterproof flat and low-sloped building roofs. Over the past ten years, there has been a substantial increase in the number of installations of white and more reflective single-ply roof systems, mostly using high density cellular foam insulation in the substrate for insulation. A major factor in the increase in the popularity of these highly insulated and more reflective roof systems is the fact that many governments began offering incentives for building owners to use reflective coverings and better insulated roofs. Now, owing to the energy efficient requirements for the design and construction of new buildings put forth in ASHRAE Standard 90.1, "Energy Standard for Buildings Except Low-Rise Residential Buildings" and the world's apparent desire to be "green" (or at least appear to be), more and more roof designs will include these reflective single-ply membranes, which use the cellular foam insulation boards to meet these requirements. Using a lower density traditional insulation will mean that the roof will have to be very thick to comply, increasing the costs of installation. High density cellular foams do not absorb water until time, vapor pressure drive, UV and thermal shock break down the foam and it becomes more absorbent. This could be 5-7 years or longer, depending on the roof construction and other factors. This means that any water that enters the roof through a breach (leak) in the membrane goes straight into the building. This is not a good consequence since the failure mode of any roof is water entering the building. Keeping the water out of the building is the purpose of the waterproofing layer. This paper reviews the techniques of moisture testing on building roofs and infrared (IR) thermography, and puts forth the idea and reasoning behind having a sacrificial layer of very absorbent insulation installed in every

  10. 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.

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

    Science.gov (United States)

    Dekker, R. W. A.; Ferraro, R. M.; Suma, A. B.; Moonen, S. P. G.

    2012-10-01

    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.

  12. 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.

  13. A Modified Coal Mine Roof Rating Classification System to Design Support Requirements in Coal Mines

    Science.gov (United States)

    Taheri, Abbas; Lee, Yongha; Medina, Mario Andres Guardado

    2017-10-01

    The coal mine roof rating (CMRR) classification system has been applied in a number of coal mines worldwide including Australia. However, the current system cannot be used directly to design support measures in underground mines. Two case studies, the Eliza Hill project in Australia and Tabas coal mine in Iran were analyzed to assess the impact of various rock properties and gallery geometry on stability and to modify the CMRR classification system. Having considered the CMRR system as a working classification system, applicable information and related coal mine data were selected from the two case records. The CMRR value was evaluated and analysed by undertaking correlation between CMRR and factor of safety, followed by a parametric study based on various rock properties and gallery geometries. To improve the applicability of the current system, the CMRR system was then modified by adding additional parameters, namely, the width of roof span and the density of overburden rock. Consequently, based on the modified CMRR system (mCMRR) roof support requirements were recommended to select the suitable rock bolting system including length and spacing of rock bolt. Numerical modelling were then undertaken to verify the support requirements recommended. The support requirements recommended by the mCMRR were found to be relatively identical with numerical analysis results. Support systems proposed by mCMRR can assist mining engineers to assess the stability of underground coal mines or verify the results of other design tools.

  14. A Modified Coal Mine Roof Rating Classification System to Design Support Requirements in Coal Mines

    Science.gov (United States)

    Taheri, Abbas; Lee, Yongha; Medina, Mario Andres Guardado

    2017-01-01

    The coal mine roof rating (CMRR) classification system has been applied in a number of coal mines worldwide including Australia. However, the current system cannot be used directly to design support measures in underground mines. Two case studies, the Eliza Hill project in Australia and Tabas coal mine in Iran were analyzed to assess the impact of various rock properties and gallery geometry on stability and to modify the CMRR classification system. Having considered the CMRR system as a working classification system, applicable information and related coal mine data were selected from the two case records. The CMRR value was evaluated and analysed by undertaking correlation between CMRR and factor of safety, followed by a parametric study based on various rock properties and gallery geometries. To improve the applicability of the current system, the CMRR system was then modified by adding additional parameters, namely, the width of roof span and the density of overburden rock. Consequently, based on the modified CMRR system (mCMRR) roof support requirements were recommended to select the suitable rock bolting system including length and spacing of rock bolt. Numerical modelling were then undertaken to verify the support requirements recommended. The support requirements recommended by the mCMRR were found to be relatively identical with numerical analysis results. Support systems proposed by mCMRR can assist mining engineers to assess the stability of underground coal mines or verify the results of other design tools.

  15. Adaptable typologies for active roofs

    NARCIS (Netherlands)

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

    2006-01-01

    The main objective of this part of the 6th framework Pan-European EUR-ACTIVE ROOF-er project is to improve the interaction between design participants of dynamic adaptable Active Roofs in product development and Active Roofs from an architects/ customers perspective. Improvements in Active Roof desi

  16. Study on determining of reinforced concrete false roof strength and design of reinforcement based on reliability theory

    Institute of Scientific and Technical Information of China (English)

    Fan Wenlu; Li Xibing; Hu Guohong

    2012-01-01

    Study on efficient mining of the steep incline and fractured ore-bodies in Yongshaba mine of Guizhou Kailin Group shows that ore-body is fractured and difficult to support the roadways in-vein. After research of the actual conditions about the ore-bodies, we have made the initial decision to adopt reconstruction of roof downward sublevel cut-andfill mining. The men work safely under the false roof supporting the top plate. However, the difficult problem is how to determine the strength of the false roof. In this case, the method based on reliability theory has been put forward. Combined with elastic mechanics and field practice, when practical value of reliable probability is 90 % , the value of the false roof strength has been calculated, and the study shows that stope span greatly influences the false roof strength. With the strength of artificial roof, the reasonable reinforcement design ensures the false roof which can supply the demand of strength under large span and load.

  17. 绿色建筑的屋顶设计%The Roof Design of Green Building

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      我们的一切能量最初都来自于太阳和天空,能量也会也会从天上反馈回来。所以屋顶,将会是我们绿色建筑设计中与自然互动最大的一块区域。%Al the energy we original y comes from the sun and sky, energy wil also come back from heaven. So the roof wil be the largest regional interaction with nature in our green building design.

  18. Law school design blends functionalism, energy conservation. [Earth-covered with ground-cover growing on roof

    Energy Technology Data Exchange (ETDEWEB)

    1976-08-01

    Construction is under way on a new University of Minnesota Law School Building, whose distinctive features include a stepped design on its southern elevation and an earth-covered roof to promote energy conservation. The design is described with emphasis on the library facilities. Energy conservation was a major design factor. The portion of the earth-covered roof will be 15 inches thick planted with low ground-cover vegetation. Overall ..mu.. value of the building envelope will be 0.11. (MCW)

  19. 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...

  20. Green roofs

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-04-01

    Full Text Available Green roofs are roofs that have been covered with a growing medium, creating a habitat on what would otherwise be a bland, lifeless surface. It is for this reason that green roofs are sometimes call 'vegetated' or 'living' roofs (Cantor 2008). A...

  1. 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.

  2. 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.

  3. Discuss the Urban Green Roof Design%城市屋顶绿化设计探讨

    Institute of Scientific and Technical Information of China (English)

    张俐

    2014-01-01

    本文论述了屋顶绿化的特点及设计方式,通过推广屋顶绿化,可使生态景观建设从地面向空中拓展。既美化了人居环境,又节约了土地。%This article discusses the characteristics and design method of roof greening. Through the promotion of roof gree-ning, people can make the ecological landscape construction expand from the ground up to the sky, which not only beautify the environment, but also save the land.

  4. Discussion on Design of Planting Green on Roofs%屋顶绿化设计探讨

    Institute of Scientific and Technical Information of China (English)

    王静

    2014-01-01

    从实际工作出发,就目前比较热门的屋顶绿化做了一些介绍,尤其是屋顶绿化的种植形式、类型以及屋顶绿化应该注意的问题,提出了屋顶绿化植物的选择方法和种植设计要点,为绿化工作者提供了参考。%Starting from the actual work, some items which should be noted especially in the form of planting green roofs were introduced, especially green roof types and other cases. This article also put forward the roof greening plant selection methods and planting design points, to provide some references for green workers.

  5. Design of self-cleaning TiO2 coating on clay roofing tiles

    Science.gov (United States)

    Hadnadjev, Milica; Ranogajec, Jonjaua; Petrovic, Snezana; Markov, Sinisa; Ducman, Vilma; Marinkovic-Neducin, Radmila

    2010-07-01

    The phenomenon of heterogeneous photocatalysis takes place in the degradation process of many organic contaminants on solid surfaces. Photocatalysis is based on the excitation of the semiconductor by irradiation with supraband gap photons and the migration of electron-hole pairs to the surface of the photocatalysts, leading to the reaction of the holes with adsorbed H2O and OH- to form hydroxyl radicals. Due to the stability and photosensitivity of TiO2 semiconductors, this system is well studied and is of great interest from an ecological and industrial point of view for use in the field of building materials. Clay roofing tiles, due to their long-term exploitation, are subject to physical, chemical and biological degradation that leads to deterioration. Ceramic systems have a high percentage of total porosity and considering their non-tolerance of organic coating, the use of surface active materials (SAM) that induce porosity in TiO2 coatings is of vital significance. Photocatalytic coatings applied on clay roofing tiles under industrial conditions were designed by varying the quantity of TiO2 (mass/cm2) on the tile surface (thin and thick TiO2 layer). The positive changes in specific surface area and mesopore structure of the designed coatings were made by the addition of PEG 600 as a surface active material. It was shown that a thin photocatalytic layer (0.399 mg suspension/cm2 tile surface), applied onto ceramic tiles under industrial conditions, had better photocatalytic activity in methylene blue decomposition, hydrophilicity and antimicrobial activity than a thick photocatalytic coating (0.885 mg suspension/cm2).

  6. Roof drainage with pressurized-water systems. Part 2. Correct dimensioning and design; Dachentwaesserung mit Druckstroemung. Teil 2. Richtig dimensionieren und bemessen

    Energy Technology Data Exchange (ETDEWEB)

    Feurich, H.

    2006-02-15

    This two-installment article discusses roof drainage with partial vacuum. Correct planning, design, construction and installation of flat roof drainage systems are gone into. The last part of the seris discusses the hydraulic dimensioning of pressurized-water pipes and provides information on the fastening of excess-pressure and partial-vacuum pipelines. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Michela Turrin

    2013-12-01

    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

  8. Floating-roof steel tanks under harmonic settlement: FE parametric study and design criterion

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Large vertical steel tanks for fluid storage are usually constructed on soft foundations, so it is not surprising that the tank wall will settle unevenly with the settlement of the foundation, thus inducing deformations and stresses in the tank. This work investigates the linear static behavior of floating-roof tanks under harmonic settlement through finite element (FE) analyses. The influences of the radius-to-thickness ratio, the height-to-radius ratio and the wind girder stiffness on the structural behavior are first analyzed. Comparisons between the circumferential stresses in the wind girder and the vertical stresses in the tank bottom are then made. The displacement and the stress along the tank height are also discussed, and the concept of tank division along its height is presented. Finally, a design approximation for the radial displacement at the tank top is developed based on FE results, and a settlement criterion based on the top radial displacement is proposed which can be used in practical design.

  9. 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.

  10. Seismic design repair and retrofit strategies for steel roof deck diaphragms

    Science.gov (United States)

    Franquet, John-Edward

    Structural engineers will often rely on the roof diaphragm to transfer lateral seismic loads to the bracing system of single-storey structures. The implementation of capacity-based design in the NBCC 2005 has caused an increase in the diaphragm design load due to the need to use the probable capacity of the bracing system, thus resulting in thicker decks, closer connector patterns and higher construction costs. Previous studies have shown that accounting for the in-plane flexibility of the diaphragm when calculating the overall building period can result in lower seismic forces and a more cost-efficient design. However, recent studies estimating the fundamental period of single storey structures using ambient vibration testing showed that the in-situ approximation was much shorter than that obtained using analytical means. The difference lies partially in the diaphragm stiffness characteristics which have been shown to decrease under increasing excitation amplitude. Using the diaphragm as the energy-dissipating element in the seismic force resisting system has also been investigated as this would take advantage of the diaphragm's ductility and limited overstrength; thus, lower capacity based seismic forces would result. An experimental program on 21.0m by 7.31m diaphragm test specimens was carried out so as to investigate the dynamic properties of diaphragms including the stiffness, ductility and capacity. The specimens consisted of 20 and 22 gauge panels with nailed frame fasteners and screwed sidelap connections as well a welded and button-punch specimen. Repair strategies for diaphragms that have previously undergone inelastic deformations were devised in an attempt to restitute the original stiffness and strength and were then experimentally evaluated. Strength and stiffness experimental estimations are compared with those predicted with the Steel Deck Institute (SDI) method. A building design comparative study was also completed. This study looks at the

  11. Sustainable roofs with real energy savings

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.; Petrie, T.W.

    1996-12-31

    This paper addresses the general concept of sustainability and relates it to the building owner`s selection of a low-slope roof. It offers a list of performance features of sustainable roofs. Experiences and data relevant to these features for four unique roofs are then presented which include: self-drying systems, low total equivalent warming foam insulation, roof coatings and green roofs. The paper concludes with a list of sustainable roofing features worth considering for a low-slope roof investment. Building owners and community developers are showing more interest in investing in sustainability. The potential exists to design, construct, and maintain roofs that last twice as long and reduce the building space heating and cooling energy loads resulting from the roof by 50% (based on the current predominant design of a 10-year life and a single layer of 1 to 2 in. (2.5 to 5.1 cm) of insulation). The opportunity to provide better low-slope roofs and sell more roof maintenance service is escalating. The general trend of outsourcing services could lead to roofing companies` owning the roofs they install while the traditional building owner owns the rest of the building. Such a situation would have a very desirable potential to internalize the costs of poor roof maintenance practices and high roof waste disposal costs, and to offer a profit for installing roofs that are more sustainable. 14 refs., 12 figs.

  12. Sustainable roofs with real energy savings

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.; Petrie, T.W.

    1996-12-31

    This paper addresses the general concept of sustainability and relates it to the building owner`s selection of a low-slope roof. It offers a list of performance features of sustainable roofs. Experiences and data relevant to these features for four unique roofs are then presented which include: self-drying systems, low total equivalent warming foam insulation, roof coatings and green roofs. The paper concludes with a list of sustainable roofing features worth considering for a low-slope roof investment. Building owners and community developers are showing more interest in investing in sustainability. The potential exists to design, construct, and maintain roofs that last twice as long and reduce the building space heating and cooling energy loads resulting from the roof by 50% (based on the current predominant design of a 10-year life and a single layer of 1 to 2 in. (2.5 to 5.1 cm) of insulation). The opportunity to provide better low-slope roofs and sell more roof maintenance service is escalating. The general trend of outsourcing services could lead to roofing companies` owning the roofs they install while the traditional building owner owns the rest of the building. Such a situation would have a very desirable potential to internalize the costs of poor roof maintenance practices and high roof waste disposal costs, and to offer a profit for installing roofs that are more sustainable. 14 refs., 12 figs.

  13. DEVELOPMENT OF DESIGNING AND APPLICATION OF GREEN ROOFS%国内外屋顶的绿化设计

    Institute of Scientific and Technical Information of China (English)

    肖敏; 张国强

    2015-01-01

    屋顶绿化是建筑节能的一种有效措施,具有显著的生态效益和景观价值,已越来越多地引起了建筑领域及相关人员的广泛关注。通过系统分析屋顶绿化在促进建筑节能、改善环境和蓄积雨水等方面的作用和效果,研究总结了国内外屋顶绿化设计的方法及其主要影响因素,包括配置模式、植被材料和栽培基质等方面的研究成果,对国内外屋顶绿化政策和实践的发展进行了回顾和比较。%As an effective measure for improvement of building energy efficiency , green roof has obvious biobenefit and landscape value , which is attracting more and more attention both in China and internationally .Through a systematic research on the effects of green roof in improving building energy saving , environment and rain accumulation , it was studied the design methods of green roof and its major influencing factors , including vegetation materials, allocation modes and cultivation substratum; and it was also reviews the progress of governmental policy and practice of green roofs in China and other countries .

  14. Carbon sequestration potential of extensive green roofs.

    Science.gov (United States)

    Getter, Kristin L; Rowe, D Bradley; Robertson, G Philip; Cregg, Bert M; Andresen, Jeffrey A

    2009-10-01

    Two studies were conducted with the objective of quantifying the carbon storage potential of extensive green roofs. The first was performed on eight roofs in Michigan and four roofs in Maryland, ranging from 1 to 6 years in age. All 12 green roofs were composed primarily of Sedum species, and substrate depths ranged from 2.5 to 12.7 cm. Aboveground plant material was harvested in the fall of 2006. On average, these roofs stored 162 g C x m(-2) in aboveground biomass. The second study was conducted on a roof in East Lansing, MI. Twenty plots were established on 21 April 2007 with a substrate depth of 6.0 cm. In addition to a substrate only control, the other plots were sown with a single species of Sedum (S. acre, S. album, S. kamtshaticum, or S. spurium). Species and substrate depth represent typical extensive green roofs in the United States. Plant material and substrate were harvested seven times across two growing seasons. Results at the end of the second year showed that aboveground plant material storage varied by species, ranging from 64 g C x m(-2) (S. acre) to 239 g C x m(-2) (S. album), with an average of 168 g C x m(-2). Belowground biomass ranged from 37 g C x m(-2) (S. acre) to 185 g C x m(-2) (S. kamtschaticum) and averaged 107 g C x m(-2). Substrate carbon content averaged 913 g C x m(-2), with no species effect, which represents a sequestration rate of 100 g C x m(-2) over the 2 years of this study. The entire extensive green roof system sequestered 375 g C x m(-2) in above- and belowground biomass and substrate organic matter.

  15. 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.

  16. Contributions to the design of rainwater harvesting systems in buildings with green roofs in a Mediterranean climate.

    Science.gov (United States)

    Monteiro, Cristina M; Calheiros, Cristina S C; Pimentel-Rodrigues, Carla; Silva-Afonso, Armando; Castro, Paula M L

    2016-01-01

    Green roofs (GRs) are becoming a trend in urban areas, favouring thermal performance of buildings, promoting removal of atmospheric pollutants, and acting as possible water collection spots. Rainwater harvesting systems in buildings can also contribute to the management of stormwater runoff reducing flood peaks. These technologies should be enhanced in Mediterranean countries where water scarcity is increasing and the occurrence of extreme events is becoming very significant, as a result of climate change. An extensive pilot GR with three aromatic plant species, Satureja montana, Thymus caespititius and Thymus pseudolanuginosus, designed to study several parameters affecting rainwater runoff, has been in operation for 12 months. Physico-chemical analyses of roof water runoff (turbidity, pH, conductivity, NH4(+), NO3(-), PO4(3-), chemical oxygen demand) have shown that water was of sufficient quality for non-potable uses in buildings, such as toilet flushing. An innovative approach allowed for the development of an expression to predict a 'monthly runoff coefficient' of the GR system. This parameter is essential when planning and designing GRs combined with rainwater harvesting systems in a Mediterranean climate. This study is a contribution to improving the basis for the design of rainwater harvesting systems in buildings with extensive GRs under a Mediterranean climate.

  17. 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

  18. Roof Rockmass Characterization in an Illinois Underground Coal Mine

    Science.gov (United States)

    Osouli, Abdolreza; Shafii, Iman

    2016-08-01

    Among all United States underground coal fields, those in Illinois have the highest rate of roof fall events due to their weak and severely moisture sensitive roof rock units. Rockmass characterization is the key initial step in designing safe and economical roof control measures in underground coal mines. In this study, a performance-based roof rockmass characterization is investigated. The geologic conditions as well as underground mine geographic specifications, roof fall analysis, mining method, utilized supplemental roof control measures, and geotechnical properties of roof rock units were considered to link the roof performance to rockmass characterization. The coal mine roof rating (CMRR) rockmass characterization method was used to evaluate the roof conditions and roof support design for an underground coal mine located in the Illinois Coal Basin. The results of several mine visit mappings, laboratory test results, and geotechnical issues and concerns are presented and discussed. The roof support designs are analyzed based on the rockmass characterization and are compared with the observed performance. This study shows that (1) CMRR index is a reasonable method for characterizing roof rockmass; (2) moisture sensitivity and bedding strengths in the horizontal direction are essential parameters for roof support design in mines with weak roof conditions; and (3) the applicability of the analysis of roof bolt system for roof support design of the studied mine is questionable.

  19. 深圳湾体育中心屋面系统的设计%ROOF SYSTEM DESIGN OF SHENZHEN BAY SPORTS CENTER

    Institute of Scientific and Technical Information of China (English)

    叶志青

    2011-01-01

    Shenzhen Bay Sports Center adopts special irregular hyperboloidal roofing system, so the waterproof and drainage design of roofing system are difficult. Most area of the roofing system adopts open structure,both upper and lower surfaces bear the wind pressure and the load distribution on the surfaces is very complcated During design, the wind load on the roofing system is selected according to the Report on Wind Tunnel Test of Shenzhen Bay Sports Center, and extreme pressure which appears once every 100 years is used for structural calculation of the standard value of wind load on roofing system.%深圳湾体育中心屋面系统造型为异型不规则双曲面,屋面系统防水和排水设计难度较大,且罩棚大部分区域为开放式结构,上下表面均承受风压,表面荷载分布极为复杂.设计时屋面系统风荷载根据选取,采用100年重现期的极值压力值作为屋面系统风荷载标准值进行结构计算.

  20. Tentative discussion on matters needing attention in steel roof truss design%浅谈钢屋架设计中应注意的要点

    Institute of Scientific and Technical Information of China (English)

    芦珍明

    2011-01-01

    从屋架选型、荷载组合、支撑布置、截面选择、构造要求及连接等方面讨论了钢屋架设计应注意的事项,指出在钢屋架结构的设计过程中应首先确定合理的屋架形式,通过受力分析确定截面尺寸,并满足规范的相关构造要求。%This paper discusses matters needing attention in aspects of roof truss selection,load composition,section selection,structure requirements and connection etc,points out steel roof truss design attentions,that is to firstly design roof truss form,to deter

  1. 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.

  2. 城市绿色屋顶生物栖息生境设计与营建研究%Urban Green Roof Habitat Designing and Construction

    Institute of Scientific and Technical Information of China (English)

    贺坤; 项耿铭; 韦捷峰; 吴威; 章银柯; 李小平

    2015-01-01

    The urbanization process has affected the use of biological habitats.The green roof however,can provide habitats and stepping stones for birds and insects.There exist great potentials for the construction of green roof for the wildlife habitats.Based of the related researches,the relationship between the green roof with wildlife habitats was discussed.The key technologies about the technical process and landscape planning and design of green roof habitat were explained.Furthermore,some examples for the construction of green roof were put forward.%城市化进程影响了生物对栖息地的利用.绿色屋顶具有营建城市野生动物栖息生境的极大潜力,可为鸟类、昆虫等在城市中迁徙提供栖息地和“踏脚石”.在相关研究的基础上,探讨了绿色屋顶与动物栖息生境的关系,从技术流程的构建、景观规划设计等方面阐述了绿色屋顶栖息生境营建的关键技术,并结合研究成果进行了具体的屋顶栖息生境营造实践.

  3. 北京通惠家园小区屋顶绿化设计评析%The green roof design of Beijing Tonghuijiayuan village

    Institute of Scientific and Technical Information of China (English)

    孙颖; 吴晖晗; 李爱芳; 韩丽霞; 车冠宇

    2015-01-01

    Taking Tonghuijiayuan community roof greening in Beijing as an example,the paper respectively carries out questionnaire for internal community residents,community managers and partial community surrounding residents,know about various users’demands for roof greening and design defects,and analyzes residential roof greening design concept,integral layout and greening design and other contents,with a view to explore new community roof greening design concepts in Beijing city.%以北京通惠家园小区屋顶绿化为实例,分别对小区内居民、小区管理者及小区周边居住区的部分居民进行了问卷访谈调研,了解了不同层面的使用者对于屋顶绿化的需求及其在设计上的不足,探析了居住区屋顶绿化的设计理念、整体布局、绿化设计等方面内容,旨在为北京市居住区屋顶绿化设计探索新思路。

  4. Understanding Roofing Systems.

    Science.gov (United States)

    Michelsen, Ted

    2001-01-01

    Reviews the various types of multi- and single-ply roofing commonly used today in educational facilities. Roofing types described involve built-up systems, modified bitumen systems; ethylene propylene diene terpolymer roofs; and roofs of thermoplastic, metal, and foam. A description of the Roofing Industry Educational Institute is included. (GR)

  5. 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.

  6. Performance assessment strategies; a computational framework for conceptual design of large roofs

    NARCIS (Netherlands)

    Turrin, M.

    2014-01-01

    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 poten

  7. 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.

  8. 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.

  9. 屋顶花园雨水利用系统设计与实践%Design and practice of rainwater utilization system for roof garden

    Institute of Scientific and Technical Information of China (English)

    曹传生; 刘慧民; 王南

    2013-01-01

      该文意在探讨利用屋面雨水对屋顶花园进行灌溉的可行性。以北大荒集团某酒店屋顶花园为例,从植物需水量、雨水可收集量、蓄水池容量及雨水收集系统等方面进行屋面雨水回收利用设计,利用彭曼-蒙特斯公式计算屋顶花园植物需水量,结果表明:5-10月屋顶花园植物需水总量为3521.78 m3,各月份间差异较大,10月份量最小仅为361.8 m3,6月份量最大为729.6 m3;同期可收集屋面雨水总量为2179.3 m3,并据雨水径流总量与初期弃流量产生的径流量设计蓄水池容量为131 m3;将收集雨水全部用于屋顶花园绿地灌溉,能节省61.88%灌溉用水;据此,采用工程技术为屋顶花园设计雨水收集系统及自动灌溉系统,对屋顶花园雨水收集量与灌溉量的水量平衡分析结果表明:利用该自动灌溉系统可节约灌溉用水67.20%,雨水利用率可达54.55%,该设计对北方干旱地区屋顶花园雨水回用技术设计具一定的实用价值和应用前景。%In recent years, urban landscape has changed from ground greening to the roof three-dimensional greening with the rapid development of landscaping in China, and a lot of roof gardens have been built to open up the new development space for the landscape in cities. Shortage of water exists in many cities, and the city water stress will turn out because of the increasing roof gardens. To solve these problem, taking the roof garden of Beidahuang group hotel as an example, we would intend to discuss the feasibility of using roof rainwater for irrigating roof garden, and design the collection and utilization of the roof rainwater following the plant evapotranspiration (ET), the rainwater collection quantity, the reservoir capacity and rainwater collection systems. Firstly, the plant water requirement in roof garden was calculated using Penman-Monteith formula and garden coefficient methods. The results showed that the

  10. 屋顶绿化工程防渗漏的优化设计探讨%On exploration for optimized design for anti-leakage of roof green project

    Institute of Scientific and Technical Information of China (English)

    向欣

    2012-01-01

    The paper analyzes the reasons for the roof leakage caused by the roof green project, points out the optimized design scheme in the construction according to the results caused by various reasons, solves the safety and roof anti-leakage problems of the roof structure, so it pro- vides direction for the development of the roof green projects.%对屋面绿化工程所造成的屋顶渗漏产生的原因进行了分析,并针对不同原因造成的后果提出在构造过程中可进行优化设计的方案,解决了屋顶构造安全问题、屋顶防漏问题,为屋顶绿化工程的发展提供指导。

  11. 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.

  12. RP{sub P}erformance, a design tool to simulate the thermal performance of high-latitude roof pond buildings (Skytherm North roof ponds); Programa de computo para la simulacion termica de sistemas de techo con estanque para latitudes altas (Skytherm North Roofponds)

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, A. G.

    2004-07-01

    This article introduces RP{sub P}erformance, a design tool to simulate the thermal performance of high-latitude roof pond buildings (also known as Skytherm North roof ponds). RP{sub P}erformance is an interactive Microsoft Excel spreadsheet that allows users to modify all the parameters that influence the thermal performance of a Skytherm North roof pond building giving as outputs the heating and cooling costs, as well as a series of indoor temperature charts for a roof pond, a highly-insulated reference building, and a conventionally insulated reference building. This article also presents the calibration study of RP{sub P}erformance using experimental results obtained over a nine-month period in an 11.9 m2 test-room located in Muncie, Indiana. (Author)

  13. 屋顶水箱TMD对加固结构的减震控制研究%Application of roof tank TMD in structural reinforcement design

    Institute of Scientific and Technical Information of China (English)

    王磊; 谭平; 方创杰; 莫艳丽; 李文彦

    2013-01-01

    Roof tank TMD is employed in structural reinforcement design of an existed international hotel in Guangdong.This paper proposes two TMD schemes.Numerical simulation is carried out to investigate the control performance of two TMDs for the hotel under various earthquake records.Results show that roof tank TMDs in structure reinforcement is feasible,effective and economic.%对某国际大酒店进行了加固改造和楼顶水箱TMD装置设计,提出了两种TMD方案,并对结构在地震激励下的控制效果进行了仿真分析,验证了屋顶水箱TMD系统对于结构改造加固的可行性与有效性.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. Structural performance of light-frame roof assemblies. I, Truss assemblies designed for high variability and wood failure

    Science.gov (United States)

    R.W. Wolfe; Monica McCarthy

    1989-01-01

    The first report of a three-part series that covers results of a full-scale roof assemblies research program. The focus of this report is the structural performance of truss assemblies comprising trusses with abnormally high stiffness variability and critical joint strength. Results discussed include properties of truss members and connections. individual truss...

  19. The green roof design of residential underground garage%住宅小区地下车库屋顶绿化设计

    Institute of Scientific and Technical Information of China (English)

    焦云祥; 殷慧

    2015-01-01

    Taking the roof greening of Taiyuan“Lake View One”residential area underground garage for example,combining with the relevant theoretical basis,this paper discussed the planning and design,technology,ways and methods,construction planting of residential underground garage roof greening,pointed out that the rise of roof greening this building form provided new construction space for increasing the amount of greening green,beautifying the urban.%以太原市“湖景壹号”住宅区地下车库屋顶绿化为例,结合相关理论基础,对住宅区地下车库屋顶绿化的规划设计、技术、方式方法、施工种植进行了探讨,指出屋顶花园这一建设形式的兴起,为增加城市绿化,美化城市提供了新的建设空间。

  20. Linking aboveground and belowground diversity

    NARCIS (Netherlands)

    Deyn, de G.B.; Putten, van der W.H.

    2005-01-01

    Aboveground and belowground species interactions drive ecosystem properties at the local scale, but it is unclear how these relationships scale-up to regional and global scales. Here, we discuss our current knowledge of aboveground and belowground diversity links from a global to a local scale. Glob

  1. New roof element system

    DEFF Research Database (Denmark)

    Ditlev, Jesper; Rudbeck, Claus Christian

    1997-01-01

    The aim of the project has been to develop an element system for warm deck roofs which, from a thermal and economical point of view, can deal with the future demands for heat loss coefficients for low slope roofs.......The aim of the project has been to develop an element system for warm deck roofs which, from a thermal and economical point of view, can deal with the future demands for heat loss coefficients for low slope roofs....

  2. 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....

  3. New roof element system

    DEFF Research Database (Denmark)

    Ditlev, Jesper; Rudbeck, Claus Christian

    1997-01-01

    The aim of the project has been to develop an element system for warm deck roofs which, from a thermal and economical point of view, can deal with the future demands for heat loss coefficients for low slope roofs.......The aim of the project has been to develop an element system for warm deck roofs which, from a thermal and economical point of view, can deal with the future demands for heat loss coefficients for low slope roofs....

  4. Green roof Malta

    OpenAIRE

    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/

  5. 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...

  6. 某体育中心屋顶光伏系统的设计探讨%Discussion on the design of a sports center roof photovoltaic system

    Institute of Scientific and Technical Information of China (English)

    戴军; 宋占强

    2015-01-01

    This paper analyzed and researched the design standards,design features and design methods of solar photovoltaic system,combining with the actual case of grid connected photovoltaic system project of a gymnasium roof,elaborated the influence of photovoltaic component,inverter selection,photovoltaic array azimuth,inclination angle,installation distance of roof grid connected photovoltaic system to photovoltaic power generation system,provided reference for future similar design.%分析研究了太阳能光伏系统的设计标准、设计特点及设计方法,结合某体育馆屋顶并网光伏系统项目的实际案例,阐述了屋顶并网光伏系统光伏组件、逆变器的选择;光伏阵列方位角、倾斜角、安装间距对光伏发电系统的影响,为今后的类似设计提供参考依据。

  7. 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.

  8. 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

  9. Cost Comparative Study On Steel Frame Folded Plate Roofing System Vs Conventional Truss Roofing System

    Directory of Open Access Journals (Sweden)

    T. Subramani

    2014-12-01

    Full Text Available Due to ever-increasing of construction materials, it becomes the foremost duty of a civil engineer to design economical and durable structures. In this project an attempt has been made to compare the cost of two types of roofing systems viz. conventional truss roofing system and steel frame folded plate roofing system. The steel frame folded plate roofing system, though found to be economical, is not widely practiced in India due to lack of knowledge regarding its analysis and design. On contrary to it, the conventional truss roofing system still remains as the widely adopted method of roofing for different types of buildings due to the available literature on its analysis, design and construction. The analysis and design of conventional truss roofing system and folded plate roofing system have been carried out for various spans. The analysis is carried out in STAAD.Pro 2004, which is based on stiffness method. Load calculations and design done manually, based on IS:875-1987, IS:800- 1984 & SP:38(1987

  10. 开合式屋盖结构的防火设计%Fireproofing design of retractable roof structure

    Institute of Scientific and Technical Information of China (English)

    林湘祁

    2011-01-01

    针对黄龙体育中心网球中心钢结构开合式屋盖进行火灾危险性分析,首先分析开合式屋盖结构的机械/控制系统,分析其耐火薄弱部位,然后设定火灾场景A、B,基于普通热辐射理论的火焰动力学,分析钢结构屋盖的温度变化.结果表明,在火灾场景A下,结构基本处于安全状态;在火灾场景B下,需要采取措施进行耐火保护,如在机械/控制系统的电动机和电路上方布置喷淋,在主拱桁架中的构件上喷涂防火涂料等.%Fire risk analysis was made on steet structure retractable roof of tennis center, Huanglong Sports Center. Firstly, a-nalysis was made on mechanical/control system and its weakest part. Then, setting fire scenarios A and B, according to flame dynamic theory, temperature change of steel structure roof was analyzed. The results showed that in fire scenario A, roof structure is safe; while in fire scenario B, countermeasures for fire protection must be took such as installing sprinkler system above electrical motor and circuit of mechanical/electrical control system, spraying fireproof coating on the main arch truss component.

  11. 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

  12. Technical considerations in green roof retrofit for stormwater attenuation in the central business district

    OpenAIRE

    Wilkinson, S.; Lamond, J.; Proverbs, D.; Sharman, L.; Heller, A; Manion, J.

    2015-01-01

    Purpose: The key aspects that built environment professionals need to consider when evaluating roofs for the purpose of green roof retrofit and also when assessing green roofs for technical due diligence purposes are outlined. Although green or sod roofs have been built over many centuries, contemporary roofs adopt new approaches and technologies. The paper aims to discuss these issues. \\ud \\ud Design/methodology/approach: A mixed methods design based on a systematic review of relevant litera...

  13. 平板太阳能集热器与建筑物屋顶的一体化结构设计%Integrated Structural Design of Flat-plate Solar Collector and Building Roof

    Institute of Scientific and Technical Information of China (English)

    梁春华; 吴永明; 曾玲

    2015-01-01

    在建筑设计阶段考虑太阳能集热器与建筑物屋顶的一体化结构设计,可以满足太阳能利用、设施维护、屋顶空间利用和建筑美学等要求。在计算出接收太阳辐射的最佳屋顶坡度的基础上,对双坡对称屋顶、双坡不对称屋顶、单坡屋顶和平屋顶等几种屋顶结构形式进行太阳能集热器安装结构的设计比较,分别分析在不同纬度地区每种屋顶结构在可利用的屋面面积、有效集热器面积和屋顶空间利用等方面的优势和劣势。为了便于太阳能集热器及其水管的安装与维护,提出了一种有维护通道的坡屋顶结构形式。%Considering the integrated structural design of solar collectors and building roof in the building design stage, it is able to satisfy the requirements of solar energy utilization, equipment mainte-nance, roof-space utilization and architectural aesthetics. On the basis of calculating the roof obliquity for best receiving solar radiation, several forms of roof structure are presented, and their advantages and disad-vantages in areas of different latitude are analyzed in roof area, effective area of solar collector and roof space utilization. To be convenient for installation and maintenance of solar collectors and their pipes, a roof structure with maintenance alleyway is presented.

  14. 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.

  15. 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

  16. 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.

  17. Horizontal roof gap of backfill hydraulic support

    Institute of Scientific and Technical Information of China (English)

    张强; 张吉雄; 邰阳; 方坤; 殷伟

    2015-01-01

    For the backfill hydraulic support as the key equipment for achieving integration of backfilling and coal mining simultaneously in the practical process, its characteristics will directly influence the backfill body’s compression ratio. Horizontal roof gap, as a key parameter of backfilling characteristics, may impact the backfilling effect from the aspects of control of roof subsidence in advance, support stress, backfilling process and the support design. Firstly, the reason why horizontal roof gap exists was analyzed and its definition, causes and connotation were introduced, then adopting the Pro/E 3D simulation software, three typical 3D entity models of backfill hydraulic supports were built, based on the influence of horizontal roof gap on backfilling effect, and influence rules of four factors, i.e. support height, suspension height, suspension angle and tamping angle, were emphatically analyzed on horizontal roof gap. The results indicate that, the four factors all have significant impacts on horizontal roof gap, but show differences in influence trend and degree, showing negative linear correlation, positive linear correlation, positive semi-parabolic correlation and negative semi-parabolic correlation, respectively. Four legs type is the most adaptive to the four factors, while six legs (II) type has the poorest adaptability, and the horizontal roof gap is small under large support height, small suspension height, small suspension angle and large tamping angle situation. By means of optimizing structure components and their positional relation and suspension height of backfill scrape conveyor in the process of support design and through controlling working face deployment, roof subsidence in advance, mining height and backfilling during engineering application, the horizontal roof gap is optimized. The research results can be served as theoretical basis for support design and guidance for backfill support to have better performance in backfilling.

  18. STUDIES ON THE LAW OF ROOF-COAL MOVEMENT BY USING THE ROOF-COAL CAVING METHOD

    Institute of Scientific and Technical Information of China (English)

    张海戈; 徐秉业; 沈新普; 王志勤

    1996-01-01

    In this paper, the law of roof-coal movement has been investigated through the fieldmeasurement, theoretical analysis and numerical calculation. Several results, which are of im-portant values for caving process, design of the supports, controlling end-face stability, raisingrecovery rate, realizing working face high output and other related aspects in practice, havebeen obtained. These results mainly include the following: roof-coal breaking curve of soft-coalseam, roof-coal movement curve of soft-coal and medium-hard coal seam, and roof-coal move-ment equation. The roof-coal caveability has been analyzed.

  19. Energy Saving Design Method in Design of Roof Garden%屋顶花园设计中的节能设计方法研究与仿真

    Institute of Scientific and Technical Information of China (English)

    王燕

    2015-01-01

    提出一种基于多参量自回归分析的屋顶花园节能设计方法.对屋顶花园节能设计中影响因素如光照、温度、湿度、绿化植被释氧量和二氧化碳吸收量等进行数学建模,充分利用的南向采光和立体采光,使得居住区的光照强度增加,采用多参量自回归分析方法,合理调度屋顶花园的空间格局,实现节能设计.仿真分析表明,采用该屋顶花园节能设计方案,能有效改善居住区的小气候环境,提高了二氧化碳吸收率,增大居住区的释氧量,实现节能环保的宜居生活.%This paper put forward a kind of regression analysis based on multi parameter design method of energy saving in Roof garden. First analysis of the overall planning and design principles of roof garden design, such as light, temperature, humidity, oxygen and carbon dioxide absorption of green vegetation quantity of mathematical modeling of roof garden ener-gy conservation design factors, make full use of lighting and three-dimensional lighting, the residential area of the light in-tensity increases, a multi parameter regression method for analysis of spatial pattern, reasonable scheduling of roof garden, to achieve energy saving design. Simulation results show that, the energy saving design of the Roof garden, can effectively improve the microclimate environment of residential area, improve the absorption rate of carbon dioxide, oxygen release in-creased residential area, to achieve energy saving and environmental protection of the livable life.

  20. Evolution of cool-roof standards in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hashem; Akbari, Hashem; Levinson, Ronnen

    2008-07-11

    Roofs that have high solar reflectance and high thermal emittance stay cool in the sun. A roof with lower thermal emittance but exceptionally high solar reflectance can also stay cool in the sun. Substituting a cool roof for a noncool roof decreases 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. Provisions for cool roofs in energy-efficiency standards can promote the building- and climate-appropriate use of cool roofing technologies. Cool-roof requirements are designed to reduce building energy use, while energy-neutral cool-roof credits permit the use of less energy-efficient components (e.g., larger windows) in a building that has energy-saving cool roofs. Both types of measures can reduce the life-cycle cost of a building (initial cost plus lifetime energy cost). Since 1999, several widely used building energy-efficiency standards, including ASHRAE 90.1, ASHRAE 90.2, the International Energy Conservation Code, and California's Title 24 have adopted cool-roof credits or requirements. This paper reviews the technical development of cool-roof provisions in the ASHRAE 90.1, ASHRAE 90.2, and California Title 24 standards, and discusses the treatment of cool roofs in other standards and energy-efficiency programs. The techniques used to develop the ASHRAE and Title 24 cool-roof provisions can be used as models to address cool roofs in building energy-efficiency standards worldwide.

  1. Green Roofs and Green Building Rating Systems

    OpenAIRE

    Liaw; Chao-Hsien

    2015-01-01

    The environmental benefits for green building from the Leadership in Energy and Environment Design (LEED) and Ecology, Energy, Waste, and Health (EEWH) rating systems have been extensively investigated; however, the effect of green roofs on the credit-earning mechanisms is relatively unexplored. This study is concerned with the environmental benefits of green roofs with respect to sustainability, stormwater control, energy savings, and water resources. We focused on the relationsh...

  2. Solar thermal roofs; Zonthermische daken

    Energy Technology Data Exchange (ETDEWEB)

    Van de Waerdt, J. [DWA installatie- en energieadvies, Bodegraven (Netherlands)

    2012-11-15

    The purpose of the brochure is to increase the effective application of solar thermal roofs. The target group includes consultants, installers, architects and contractors. Attention is paid to the design, parameters for comparison, yield simulations and experiences gained in projects [Dutch] Het doel van de brochure is het vergroten van de effectieve toepassing van zonthermische daken. Tot de doelgroep behoren installatieadviseurs, installateurs, architecten en opdrachtgevers in de bouw. Aandacht wordt besteed aan het ontwerp, parameters voor vergelijking, opbrengstsimulaties en ervaringen opgedaan in projecten.

  3. A venturi-shaped roof for wind-induced natural ventilation of buildings: Wind tunnel and CFD evaluation of different design configurations

    NARCIS (Netherlands)

    Van Hooff, T.; Blocken, B.; Aanen, L.; Bronsema, B.

    2011-01-01

    Wind tunnel experiments and Computational Fluid Dynamics (CFD) are used to analyse the flow conditions in a venturi-shaped roof, with focus on the underpressure in the narrowest roof section (contraction). This underpressure can be used to partly or completely drive the natural ventilation of the bu

  4. Mine roof supports

    Energy Technology Data Exchange (ETDEWEB)

    Dettmers, M.; Peters, B.; Weirich, W.

    1983-12-27

    A mine roof support has hydraulic props mounted between a floor sill and a roof bar which can be raised and lowered by extension and retraction of the props. A goaf shield is pivotably connected to the rear of the roof bar and is linked via levers to the floor sill. A hydraulic piston and cylinder unit is connected between the roof bar and the goaf shield. Apparatus serves to prevent damage to the support components, and especially to the unit which could be extended beyond its full stroke when the props are retracted to bring the goaf shield and the roof bar more or less into alignment. The protective apparatus is composed of a compact valve device operated by a member, such as a cam, to block the props from hydraulic pressure when the goaf shield and the roof bar assume a pre-determined angular disposition. Both the valve device and its operating member are disposed in a protected position within chambers formed inside the roof bar and the goaf shield adjacent the pivot connection therebetween.

  5. 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...

  6. Research on hydraulic-powered roof supports test problems

    Institute of Scientific and Technical Information of China (English)

    SUN Hong-bo; JIANG Jin-qiu; MA Qiang

    2011-01-01

    The load-bearing characters of hydraulic-powered roof support with dual telescopic legs were analyzed. With a specific type hydraulic-powered roof support with dual telescopic legs for research object, the inside load test problems in factories was analyzed, and the correct test methods were given, which can enhance the test efficiency and make the factories away from the error design of hydraulic-powered roof supports and legs.

  7. 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.)

  8. 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.

  9. Legacy effects of aboveground-belowground interactions.

    Science.gov (United States)

    Kostenko, Olga; van de Voorde, Tess F J; Mulder, Patrick P J; van der Putten, Wim H; Martijn Bezemer, T

    2012-08-01

    Root herbivory can greatly affect the performance of aboveground insects via changes in plant chemistry. These interactions have been studied extensively in experiments where aboveground and belowground insects were feeding on the same plant. However, little is known about how aboveground and belowground organisms interact when they feed on plant individuals that grow after each other in the same soil. We show that feeding by aboveground and belowground insect herbivores on ragwort (Jacobaea vulgaris) plants exert unique soil legacy effects, via herbivore-induced changes in the composition of soil fungi. These changes in the soil biota induced by aboveground and belowground herbivores of preceding plants greatly influenced the pyrrolizidine alkaloid content, biomass and aboveground multitrophic interactions of succeeding plants. We conclude that plant-mediated interactions between aboveground and belowground insects are also important when they do not feed simultaneously on the same plant.

  10. TECHNICAL CONSIDERATIONS FOR THE PLANNING OF ROOF GARDENS

    Directory of Open Access Journals (Sweden)

    Nizamettin KOÇ

    1998-01-01

    Full Text Available Increases in population, buildings, traffic density and air pollution is the most specific characteristics of metropol cities. These conditions effect the living quality negatively. That is why architectures and planners should find both aesthetic and functional planning approach in urban areas. Roof gardens, which affect positively urban ecology in many ways, have an important place in this approach. Planning aproach of roof gardens are rather different compare to ground level design. Structural elements under the roof gardens againist the infiltration of water. That is why it is important that roof garden plannings should have some layers shuclh as drainage, insulation, waterproofing, filter layers and irrigation andf drainage systems.

  11. 浅析重庆山地建筑屋顶设计%Analysis of the Chongqing Mountain Building Roof Design

    Institute of Scientific and Technical Information of China (English)

    邓学华

    2014-01-01

    Roof form may have great differences in different regions, different area, each has its diferent characteristics. Based on the analysis of Chongqing topography and the chara- cteristics of climate, this paper introduces the green roof of Ch- ongqing, and puts forward the importance of rich roof mould, hopes can provide some reference to the roof of building.%房屋屋顶的造型在不同地区、不同的地域会有很大的差异,各有其不同特色。本文在分析重庆的地形和气候特点的基础上,介绍了重庆的绿色屋顶,并提出了丰富屋顶造型的重要性,希望可以给屋顶的建设提供一些参考。

  12. 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.

  13. 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...

  14. NC green roof stormwater quantity and quality field evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Moran, A.; Hunt, B.; Jennings, G. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Biological and Agricultural Engineering

    2004-07-01

    A study was conducted in an effort to establish design standards for green roofs in North Carolina (NC). It was conducted in light of recent regulations that require stormwater runoff to be treated by structural controls in urban development. Two extensive green roofs were constructed within the Neuse River Basin in order to estimate the per cent of precipitation retained by the green roof; estimate the per cent peak flow reduction; determine whether green roofs can be used as nutrient reduction best management practices (BMPs) and if so, what removal efficiency should be assigned to green roofs; identify green roof vegetation types that thrive in central and eastern NC and find an optimal depth of soil for desirable plant growth. The determining factors for greater water retention were found to be soil depth and plant selection. BMPs such as bioretention areas, wet and dry detention ponds, constructed wetlands, and sand filters are commonly seen throughout NC. A new option for BMPs is the green roof to use thousands of square feet available on rooftops that would not otherwise be available on the ground. Each green roof in this study retained about 60 per cent of the total recorded rainfall during a nine-month observation period. The average peak flow reduction for both green roofs was about 85 per cent. Water quality data indicated that higher concentrations of total nitrogen and total phosphorous were present in the green roof runoff than in the control roof runoff and in the rainfall at each green roof site. This may be a result of N and P leaching from the soil media, which was composed of 15 per cent compost. It was suggested that leaching could be reduced with less organic matter present in the soil media. 12 refs., 1 tab., 8 figs.

  15. Storm Water Retention on Three Green Roofs with Distinct Climates

    Science.gov (United States)

    Breach, P. A.; Sims, A.; O'Carroll, D. M.; Robinson, C. E.; Smart, C. C.; Powers, B. S. C.

    2014-12-01

    As urbanization continues to increase the impact of cities on their surrounding environments, the feasibility of implementing low-impact development such as green roofs is of increasing interest. Green roofs retain and attenuate storm water thereby reducing the load on urban sewer systems. In addition, green roofs can provide insulation and lower roof surface temperature leading to a decrease in building energy load. Green roof technology in North American urban environments remains underused, in part due to a lack of climate appropriate green roof design guidelines. The capacity of a green roof to moderate runoff depends on the storage capacity of the growing medium at the start of a rainfall event. Storage capacity is finite, which makes rapid drainage and evapotranspiration loss critical for maximizing storage capacity between subsequent storms. Here the retention and attenuation of storm events are quantified for experimental green roof sites located in three representative Canadian climates corresponding to; semiarid conditions in Calgary, Alberta, moderate conditions in London, Ontario, and cool and humid conditions in Halifax, Nova Scotia. The storage recovery and storm water retention at each site is modelled using a modified water balance approach. Components of the water balance including evapotranspiration are predicted using climate data collected from 2012 to 2014 at each of the experimental sites. During the measurement period there were over 300 precipitation events ranging from small, frequent events (green roofs in their respective climates.

  16. 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.

  17. Integrated roof wind energy system

    Science.gov (United States)

    Suma, A. B.; Ferraro, R. M.; Dano, B.; Moonen, S. P. G.

    2012-10-01

    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.

  18. Green Roofs and Green Building Rating Systems

    Directory of Open Access Journals (Sweden)

    Liaw

    2015-01-01

    Full Text Available The environmental benefits for green building from the Leadership in Energy and Environment Design (LEED and Ecology, Energy, Waste, and Health (EEWH rating systems have been extensively investigated; however, the effect of green roofs on the credit-earning mechanisms is relatively unexplored. This study is concerned with the environmental benefits of green roofs with respect to sustainability, stormwater control, energy savings, and water resources. We focused on the relationship between green coverage and the credits of the rating systems, evaluated the credits efficiency, and performed cost analysis. As an example, we used a university building in Keelung, Northern Taiwan. The findings suggest that with EEWH, the proposed green coverage is 50–75%, whereas with LEED, the proposed green coverage is 100%. These findings have implications for the application of green roofs in green building.

  19. 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.

  20. Practice And Discussion Which Is Based On The Integrated Design Of Green Roof Types%基于屋顶绿化类型的一体化设计探讨与实践

    Institute of Scientific and Technical Information of China (English)

    向俊米; 刘宏成; 肖敏; 刘健璇

    2016-01-01

    Green roofs can effectively improve the indoor environment and forming certain ecological effect, but also exist some construction and maintenance problem. According to the characteristics of the original architecture, based on"low price and high eficiency" principle, it connects diferent types of roof greening to the coresponding integrated design, and puts into practice and achieved good efect with good reference value to the design of roof greening.%屋顶绿化能有效改善室内环境,形成一定的生态效应,同时也存在着施工与维护困难等相应的问题。以原有建筑为依据结合“低价高效”的原则,对不同类型的屋顶绿化进行一体化设计的相应探讨,并付诸实践,取得了良好的效果,对屋顶绿化设计有较好的参考价值。

  1. The Design of Drainage System for External Floating Roof Tank in International Stockpile Project%浅谈国际储备库浮顶排水系统的设计选用

    Institute of Scientific and Technical Information of China (English)

    谭可昕

    2012-01-01

    Large external floating roof storage tank is widely used in petroleum,chemical,civil construction,transportation,metallurgy,national defense and other important fields.Central drainage system is the main accessory for external floating roof tank,its analysis and comparison of structure and type are important for the tank design.The paper summarized the design of central drainage system for external floating roof tank in international stockpile project.%大型外浮顶储罐广泛应用于石油、化工、市政建设、交通、冶金、国防等领域。中央排水系统是外浮顶罐的主要附件,其结构类型的分析和比较是储罐设计中的重要问题。文章综述了在国内一国际储备库项目中,外浮顶罐中央排水系统的设计选用。

  2. 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.

  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. STRUCTURAL SELECTION AND DESIGN OF GYMNASIUM ROOF IN DAQING OLYMPIC SPORTS CENTER%大庆市奥体中心体育馆屋盖结构选型及设计

    Institute of Scientific and Technical Information of China (English)

    张建亮; 刘海峰; 曹正罡; 武岳; 周观根

    2014-01-01

    大庆市奥体中心体育馆屋盖结构采用主要由立体拱桁架组成的多层次传力的复杂空间受力体系,并引入幕墙桁架参与主结构受力,体现了结构技术与建筑艺术完美结合的特点。依据建筑造型要求和下部支承条件,对所提出的3种屋盖结构方案进行概念设计选型,并对优选出的方案进行计算分析,通过对比各种设计指标最终得到最优的结构方案;最后根据选型得到的结构方案进行结构设计。结果表明:该结构方案不仅能够完全满足建筑造型及使用功能要求,而且受力合理、经济性较好。%Daqing Olympic Sports Center gymnasium ’ s roof uses a complicated multi-level force transmission spatial structure, which is mainly composed by stereo trussed arch .And the truss of the curtain wall is brought in the main structure to bear stress.The gymnasium’s roof is a perfect combination of structure technology and architectural art . This paper introduced the structural selection and design of the roof in detail .First, according to the supporting conditions and the architectural modeling , three roof structure schemes were given .Then concept design was brought on and the unreasonable structure scheme was removed .Based on which , the rest schemes were computationally analyzed, and kinds of design index were compared .Moreover, the best structure scheme was gotten .In the end, the roof structure is designed , and the result shows that the structure scheme not only can meet the requirement of architectural shape completely , but also has good mechanical performance and economy .

  5. 压力流虹吸式屋面雨水排水系统的设计与应用探讨%Discussion on Design and Application of Siphon Roof Rainwater Drainage System

    Institute of Scientific and Technical Information of China (English)

    潘俊杰; 何蓉

    2011-01-01

    Based on analysis of working principle of siphon roof rainwater drainage system, the siphon drainage system is compared with the gravity rainwater drainage system. The characteristics and advantages of siphon roof rainwater drainage system are discussed. Some problems in design and application of this system are explored. It is concluded that although the siphon roof rainwater drainage system is one of the effective ways to solve the problems of roof rainwater drainage of industrial and public buildings with large area and large span, it should be prudently used for high-rise buildings.%在分析压力流虹吸式屋面雨水排水系统工作原理的基础上,对该排水方式与传统重力流雨水排水方式进行了比较,讨论了压力流虹吸式屋面雨水排水系统的特点和优势,并对压力流虹吸式屋面雨水排水系统的设计与应用中的几个问题进行了探讨和分析.压力流虹吸式屋面雨水排水系统虽然是解决大面积、大跨度的工业厂房与公共建筑物的屋面雨水排水问题最有效的方式之一,但在高层建筑中应审慎采用.

  6. Quality of Rainwater from Different Roof Material

    Directory of Open Access Journals (Sweden)

    Olaoye, R.A

    2012-08-01

    Full Text Available Roof material is an important consideration when designing a rainwater catchment system .This is because it affects the quality of the harvested rainwater which invariably affects the usage as potable or non potable.This study was carried out to determine the quality of rainwater from four different roofing materials (asbestos, aluminium, concrete and corrugated plastic within Ogbomosho North Local Government Area of Oyo State, Nigeria, between the months of July to October, 2011. The rainwater samples were taken to the laboratory and analyzed as recommended by Nigerian standard for Drinking Water Quality (NSDQW and World Health Organization (WHO.All the Physical and most of the chemical parameters analyzed conformed to the recommended standard value apart from chloride and total hardness value. Of interest is the rainwater sample from asbestos roofing sheet which had the highest mean value for pH (6.75, total hardness (84 – 86mg/l, aluminium concentration (3 – 9 mg/l, copper (0.03 – 0.04 mg/l, nitrate (31.9 – 39mg/l, and sulphate value between 11- 14mg/l, although, all these parameters fell within the standard values. However, Coliform as bacterial indicator was present in samples from asbestos, concrete and corrugated plastic roof, only the aluminium roof was free from pathogenic contamination. To ensure that the rainwater harvested satisfies health requirement for consumption as specified, all the harvested rainwater should be given some level of treatment in terms of pH, total hardness, chloride concentration and bacterial contamination. It was recommended that the rainwater from all the roofs in this case study area, be carefully examined. Consequently, if the harvested rainwater is being considered for domestic use, the gutters and the catchment areas should be regularly cleaned to remove animal droppings and leaves from over hanging trees as well as boiled to adequate temperature.

  7. Optimizing the building envelopes with green roofs : a discussion of architectural and energy performance requirements

    Energy Technology Data Exchange (ETDEWEB)

    Hagerman, J. [Columbia Univ., New York, NY (United States). Dept. of Civil Engineering]|[Rafael Vinoly Architects, New York, NY (United States); Hodge, D. [Rafael Vinoly Architects, New York, NY (United States)

    2006-07-01

    This paper provided recommendations for optimized green roof technologies inspired by an architect firm's involvement in designing a 255,000 square foot green roof on top of the Howard Hughes Medical Institute's Janelia Farm Research Campus in Virginia. During the course of the green roof construction and installation, the architects found that green roofs needed design flexibility to meet their conceptual design requirements. It was suggested that the use of a modular system might allow for easier inspection access as well as the ability for the planting material to be reconfigured. It was noted that green roof systems can sometimes conflict with water management strategies of the building envelope. Green roof component lists do not make reference to the layers of construction within the building envelope, as it is often assumed that they are irrelevant to green roof design. Modular products offer Architects flexibility in design and maintenance, and products can be incorporated into more sophisticated water management details, offering simplicity of design, ease of installation, and ease of roof membrane inspection. A thermal analysis of modular and monolithic roof assemblies was conducted which showed that the assemblies contributed very little to the overall thermal insulation envelope when the positive thermal benefits of the green roof failed. It was recommended that green roof installations should be designed to sit directly on top of the roof membranes to replace the building's insulation envelope. Foamglas was proposed as a material for building insulation and to prevent root penetration. An evaluation of the R-values of various green roof systems at failure was also provided to give guidance to Architects incorporating green roofs in building envelopes. 3 refs., 3 tabs., 8 figs.

  8. 中原城市屋顶花园景观设计研究%The Research of Landscape Design of Urban Building Roof Gardens at Central Plains Region in China

    Institute of Scientific and Technical Information of China (English)

    敬威

    2011-01-01

    By analyzing factors against? the sites at building roofs at urban areas of Central Plains, local climate, traditional garden culture, a design strategy is established in the consideration of vegetation allocation, Waterscape design and local culture interpretation.%通过对中原城市的屋顶场地、自然气候、传统园林文化等因素的分析,制定了中原城市屋顶花园在植物配置、水景设计、地域文化表达方面的设计策略。

  9. Producing superhydrophobic roof tiles

    Science.gov (United States)

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

    2016-03-01

    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.

  10. 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

    and insulation has to be fulfilled. Based on a given design of the tapered insulation the total heat loss coefficient of the roof can be calculated using formulae in EN ISO 6946 for typical segments of the tapered insulation. Performing design and calculations for large roofs with numerous different segments can...... for design of flat roofs and a pc-program that can be used for calculating the total heat loss coefficient of externally insulated roofs with insulation in tapered layers, taking into account thermal bridges in the roof construction.......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...

  11. Analysis of mechanical behaviors of big pipe roof for shallow buried large-span tunnel

    Institute of Scientific and Technical Information of China (English)

    Li Jian; Tan Zhongsheng; Yu Yu; Guo Xiaohong

    2013-01-01

    A series of researches on mechanical behaviors of big pipe roof for shallow large-span loess tunnel were carried out based on the Wenxiang tunnel in Zhengzhou-Xi’an Special Passenger Railway. The longitudinal de-formations of the pipe roofs were monitored and the mechanical behaviors of the pipe roofs were analyzed at the test section. A new double-parameter elastic foundation beam model for pipe roof in shallow tunnels was put for-ward in Wenxiang tunnel. The measured values and the calculation results agreed well with each other,revealing the force-deformation law of big pipe roof in loess tunnel:At about 15 m in front of the excavating face,the pipe roof starts to bear the load;at about 15 m behind the excavating face,the force of the pipe roof tends to be stabi-lized;the longitudinal deformation of the whole pipe roofs is groove-shaped distribution,and the largest force of pipe roofs is at the excavating face. Simultaneously,the results also indicate that mechanical behaviors of pipe roof closely relate to the location of the excavation face,the footage of the tunnelling cycle and the mechanics pa-rameters of pipe roof and rock. The conclusions can be reference for the design parameter optimization and the con-struction scheme selection of pipe roofs,and have been verified by the result of numerical analysis software FLAC3D and deformation monitoring.

  12. Stormwater Attenuation by Green Roofs

    Science.gov (United States)

    Sims, A.; O'Carroll, D. M.; Robinson, C. E.; Smart, C. C.

    2014-12-01

    Innovative municipal stormwater management technologies are urgently required in urban centers. Inadequate stormwater management can lead to excessive flooding, channel erosion, decreased stream baseflows, and degraded water quality. A major source of urban stormwater is unused roof space. Green roofs can be used as a stormwater management tool to reduce roof generated stormwater and generally improve the quality of runoff. With recent legislation in some North American cities, including Toronto, requiring the installation of green roofs on large buildings, research on the effectiveness of green roofs for stormwater management is important. This study aims to assess the hydrologic response of an extensive sedum green roof in London, Ontario, with emphasis on the response to large precipitation events that stress municipal stormwater infrastructure. A green roof rapidly reaches field capacity during large storm events and can show significantly different behavior before and after field capacity. At field capacity a green roof has no capillary storage left for retention of stormwater, but may still be an effective tool to attenuate peak runoff rates by transport through the green roof substrate. The attenuation of green roofs after field capacity is linked to gravity storage, where gravity storage is the water that is temporarily stored and can drain freely over time after field capacity has been established. Stormwater attenuation of a modular experimental green roof is determined from water balance calculations at 1-minute intervals. Data is used to evaluate green roof attenuation and the impact of field capacity on peak flow rates and gravity storage. In addition, a numerical model is used to simulate event based stormwater attenuation. This model is based off of the Richards equation and supporting theory of multiphase flow through porous media.

  13. Humble Opinion of Roof Gardens

    Institute of Scientific and Technical Information of China (English)

    WANGXiaoxiao; MAQiangqiang; CAOXiaojun

    2005-01-01

    With the swift development of urban construction in China and the boost in people's demands for green environments in cities, roof gardens are widely used as a new way of greening. This paper deals chiefly with the functions, building principle, classification and composing elements of roof gardens, an analysis of main ecological factors, loads, and waterproof. It suggests that roof gardens will bring about a comparatively big leap in city greening both quantitatively and qualitatively.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Numerical analysis of application for induction caving roof

    Institute of Scientific and Technical Information of China (English)

    HU Jian-hua; ZHOU Ke-ping; LI Xi-bing; YANG Nian-ge; SU Jia-hong

    2005-01-01

    New method for handling roof of the base successive mining is proposed, which is induction caving in the roof. The key is that it is made certain to the station of the space-time in the induction caving roof, as the stress is released with the mining process. And applying the catastrophe theory, the influencing factors of induction caving roof are studied in the emptied areas, such as the mechanical property of the surrounding rock, the area of the gob,the scope and dimension of tensile stress. The results show that the key factor is the area of the gob to the method of the induction caving roof. Then according to the geology and the ore characteristic, the three dimension FEM mechanical model is built in Tongkeng Mine, the laws of the tensile stress are analyzed to the space and the time in the roof with the mining, then it is rational design to the mine step and time of the handing the roof.

  19. 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.

  20. Theoretical relationships between first flush of roof runoff and influencing factors

    Institute of Scientific and Technical Information of China (English)

    Biao WANG; Tian LI

    2009-01-01

    Considering the short length of building roofs,a theoretical analysis of the first flush of roof runoff was conducted based on the kinematic wave and pollutant erosion equations.This mathematical derivation with analytical solutions predicts pollutant mass first flush(MFF),mean concentration of initial runoff(MCIF),mean concentration of roof runoff(MCRRl with diversion of initial portion and residual mass available on the bed surface (RS) after the entire rnnoff under the condition of constant excess rainfall.And the effects of the associated influencing factors(roof length,roof gradient,roof surface roughness.rainfall intensity,rainfall duration,and erosion coefficients)on them were discussed while the values of parameters referred to the previous studies.The results showed that for roofs whose length is shorter than 20 m.both the increase in roof length and roof gradient and the decrease in roof surface roughness result in larger MFF and MCIF and smaller MCRR and RS.which is beneficial to water reuse and pollution reduction.The theoretical relationship between the first flush and the influencing factors may aid the planning and design of roof in terms of rainwater utilization or diffuse pollution control.

  1. Reliability Analysis of a Green Roof Under Different Storm Scenarios

    Science.gov (United States)

    William, R. K.; Stillwell, A. S.

    2015-12-01

    Urban environments continue to face the challenges of localized flooding and decreased water quality brought on by the increasing amount of impervious area in the built environment. Green infrastructure provides an alternative to conventional storm sewer design by using natural processes to filter and store stormwater at its source. However, there are currently few consistent standards available in North America to ensure that installed green infrastructure is performing as expected. This analysis offers a method for characterizing green roof failure using a visual aid commonly used in earthquake engineering: fragility curves. We adapted the concept of the fragility curve based on the efficiency in runoff reduction provided by a green roof compared to a conventional roof under different storm scenarios. We then used the 2D distributed surface water-groundwater coupled model MIKE SHE to model the impact that a real green roof might have on runoff in different storm events. We then employed a multiple regression analysis to generate an algebraic demand model that was input into the Matlab-based reliability analysis model FERUM, which was then used to calculate the probability of failure. The use of reliability analysis as a part of green infrastructure design code can provide insights into green roof weaknesses and areas for improvement. It also supports the design of code that is more resilient than current standards and is easily testable for failure. Finally, the understanding of reliability of a single green roof module under different scenarios can support holistic testing of system reliability.

  2. 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.

  3. A School on Roof

    Institute of Scientific and Technical Information of China (English)

    ZhouChao

    2005-01-01

    March 23, Wednesday, Wuhan. It was a raining and cloudy day. One month passed but still more than 20 students had yet registered in Lingzhi Elementary School in Jianghan District, Wuhan, capital city of central Hubei Province. Zhu Zhongfan habitually looked out to the stairway of the building. “Whenever a new semester begins, a dozen of students will not come. They either go back to their hometowns or transfer to other school or even drop out.” Zhu, 49 years old, is the headmaster of the school. He began teaching at 19 and founded this school in 1999. Currently, there are 406 registered students, most of which are children of migrant workers from the countryside. As it is extremely hard to find a cheap place for school, Zhu had to locate his school on the roof of a vegetable fair building. Everyday, student's reciting of textbooks mixes with shouting of vendors, orchestrating unique symphonic melodies.

  4. Design Summary of the Roof of Underground Garage with Flat Slab%地下车库顶板采用无梁楼盖设计小结

    Institute of Scientific and Technical Information of China (English)

    徐佶霆; 邢宁波

    2014-01-01

    无梁楼盖体系被广泛应用于大面积地下车库顶板结构。本文从无梁楼盖基本计算方法着手,根据不同的地库功能(地下车库是否兼顾人防设施)以及常见柱网的尺寸和覆土厚度,总结归纳了部分地库顶板无梁楼盖配筋面积表格。%The flat slab system is widely used in large area roof of underground garage structure. In this paper, the basic calculation method of flat slab is used, according to the dif-ferent function of underground garage (whether underground garage contains air-raid defense facilities) and common co-lumn grid size and the thickness of earth covering, the rein-forcement area form with flat slab of partial roof of und-erground garages is summarized.

  5. 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.

  6. Energy Performance Impacts from Competing Low-slope Roofing Choices and Photovoltaic Technologies

    Science.gov (United States)

    Nagengast, Amy L.

    With such a vast quantity of space, commercial low-slope roofs offer significant potential for sustainable roofing technology deployment. Specifically, building energy performance can be improved by installing rooftop energy technologies such as photovoltaic (PV) panels, and/or including designs such as white or green roofs instead of traditional black. This research aims to inform and support roof decisions through quantified energy performance impacts across roof choices and photovoltaic technologies. The primary dataset for this research was measured over a 16 month period (May 24, 2011 to October 13, 2012) from a large field experiment in Pittsburgh, Pennsylvania on top of a commercial warehouse with white, black and green roof sections, each with portions covered by polycrystalline photovoltaic panels. Results from the Pittsburgh experiment were extended to three different cities (San Diego, CA; Huntsville, AL; and Phoenix, AZ) chosen to represent a wide range of irradiance and temperature values. First, this research evaluated the difference in electricity production from a green-moss roof and black roof underneath photovoltaic panels to determine if the green roof's cooler air increases the panel efficiency. Second, separate studies examine 1) average hourly heat flux by month for unobstructed and shaded roof membranes 2) heat flux peak time delay, and 3) air temperature across roof types. Results of this research show green roofs slightly increased (0.8-1.5%) PV panel efficiency in temperatures approximately at or above 25° C (77°F) compared to black roofs. However in cool climates, like Pittsburgh, the roof type under the PV panels had little overall impact on PV performance when considering year round temperatures. Instead, roof decisions should place a stronger emphasis on heat flux impacts. The green roof outperformed both black and white roofs at minimizing total conductive heat flux. These heat flow values were used to develop a new, straight

  7. 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...

  8. 上海世博会罗阿案例馆种植屋面的灌溉系统设计%Design of Planted Roof Irrigation System of Rhone-Alps Case Pavilion in World Expo Shanghai

    Institute of Scientific and Technical Information of China (English)

    徐钟骏

    2012-01-01

    The construction of the planted roof irrigation system's control theory and design features in the Rhone-Apes case of 2010 Shanghai World Expo was introduced. By analyzing the relationship between the rainfall, relative humidity and the irrigation required water quantity, irrigation influence factors of the quantity of irrigation water and annual changes were illustrated and the execution of water-saving technology in planted roof irrigation system was summarized.%该文介绍了2010年上海世博会法国罗纳-阿尔卑斯案例馆种植屋面灌溉系统的构造、控制原理及设计要点,通过分析降雨量、相对湿度和浇灌用水量的相互关系,说明了浇灌用水量的影响因素及年度变化情况,阐述了节水技术在种植屋面灌溉系统中的具体实施及运用,为其他同类型项目节水设计提供了很好的借鉴.

  9. 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 machines with integral roof bolters. 75.205 Section 75.205 Mineral Resources MINE SAFETY AND HEALTH... Roof Support § 75.205 Installation of roof support using mining machines with integral roof bolters...

  10. 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

  11. Physico-technical measurement of green roof in climate chamber module

    Directory of Open Access Journals (Sweden)

    Baláž Richard

    2015-06-01

    Full Text Available Not for nothing it is said that "a good roof is priceless." Although it may lead to discussions, which roof is good, because there are a lot of requirements and criteria for the functional characterization. It must be understood that the roof structure defines the durability of the building as a unit, therefore it defines lifetime of other parts of the building and also the function of space that is covered by the roof. Therefore it is very important to pay particular attention to the design, as well as the realization of the roof structure. The aim of this publication is to judge the physical and technical parameters in the design of the roof coating module in a climatic chamber.

  12. Roof Weakening of Hydraulic Fracturing for Control of Hanging Roof in the Face End of High Gassy Coal Longwall Mining: A Case Study

    Science.gov (United States)

    Huang, Bingxiang; Wang, Youzhuang

    2016-09-01

    The occurence of hanging roof commonly arises in the face end of longwall coal mining under hard roof conditions. The sudden break and subsequent caving of a hanging roof could result in the extrusion of gas in the gob to the face, causing gas concentrations to rise sharply and to increase to over a safety-limited value. A series of linear fracturing-holes of 32 mm diameter were drilled into the roof of the entries with an anchor rig. According to the theory that the gob should be fully filled with the fragmentized falling roof rock, the drilling depth is determined as being 3 5 times the mining height if the broken expansion coefficient takes an empirical value. Considering the general extension range of cracks and the supporting form of the entryway, the spacing distance between two drilling holes is determined as being 1 2 times the crack's range of extension. Using a mounting pipe, a high pressure resistant sealing device of a small diameter-size was sent to the designated location for the high-pressure hydraulic fracturing of the roof rock. The hydraulic fracturing created the main hydro-fracturing crack and airfoil branch cracks in the interior of the roof-rock, transforming the roof structure and weakening the strength of the roof to form a weak plane which accelerated roof caving, and eventually induced the full caving in of the roof in time with the help of ground pressure. For holes deeper than 4 m, retreating hydraulic fracturing could ensure the uniformity of crack extension. Tested and applied at several mines in Shengdong Mining District, the highest ruptured water pressure was found to be 55 MPa, and the hanging roof at the face end was reduced in length from 12 m to less than 1 2 m. This technology has eliminated the risk of the extrusion of gas which has accumulated in the gob.

  13. 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.

  14. 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.

  15. Comparison of the Behaviour of Curved and Straight Types of Steel Shell Roof Structures

    OpenAIRE

    Behnamasl, Mana

    2010-01-01

    ABSTRACT: In this research, the straight and curved models of the steel shell roof with different plates were analysed, designed and the results were compared with one another. Through this exercise it is aimed at achieving an ideal shell roof structure which could cover a larger surface. Therefore, three types of shell roofs were considered duopitch, cylindrical and dome and the main objective was to compare the straight and curved model of the shells. According to the findings of the liter...

  16. Evaluation of energy roof direct utilization

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.; Rossetto, L.; Viero, L.

    1984-04-01

    Energy roofs are roofing systems equipped with channels which allow both solar and atmospheric energy collection. They were conceived as cold source for heat pump systems. The behavious of an energy roof in DHW direct heating was studied; this might extend energy roof utilization all year long. The estimates were performed through more reliable recently proposed correlations for wind convection heat transfer coefficients. The advantage of annual energy roof utilization in DHW direct heating is predictable.

  17. 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.

  18. [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.

  19. Hydrological Performance of Green Roofs

    OpenAIRE

    Poorova, Zuzana; Vranayova, Zuzana

    2015-01-01

    There should be a balance between artificial environment and natural environment. As forests, fields, gardens and urban lands are being replaced with bituminous, concrete and unnatural surfaces, necessity of recovering green and blue spaces and natural areas is becoming more and more critical. Green roof is a tool in strategy of making more pervious areas and beating more impervious areas. Green roof is lately becoming part of urban storm water management. Considering this fact, new construct...

  20. Soil-water fluxes modelling in a green roof

    Science.gov (United States)

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

    2014-05-01

    Green roofs differ from a natural environment as they are on top of a building and are not connected to the natural ground; therefore it is critical that soils can drain and retain water simultaneously and that they work even in very shallow systems. The soil or growing medium used for green roofs is specifically engineered to provide the vegetation with nutrients, discharging any excess water into the drainage layer, and releasing stored water back into the substrate. In this way, medium depth and porosity plays an important role in stormwater retention and plant growth in a green roof. Due to the lack of a good understanding about the hydraulic efficiency of each green roof's layer in rainwater management, a detailed analysis of the hydrological dynamics, connected 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 research is analyzing the soil-water dynamics through the different components of a green roof and modeling these processes though a detailed but clear subsurface hydrology module, based on green roof vertical soil water movement reproduction, in relation to climate forcing, basic technology components and geometric characteristics of green roof systems (thickness of the stratigraphy, soil layers and materials, vegetation typology and density). A multi-layer bucket model has been applied to examine the hydrological response of the green roof system under a temperate maritime climate, by varying the physical and geometric parameters that characterize the different components of the vegetated cover. Following a stage of validation and calibration, results confirm the suitability of the model to describe the hydrologic response of the green roof during the observed rainfall events: the discharge hydrograph profile, volume and timing, predicted by the model, matched experimental measurements

  1. 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).

  2. 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).

  3. Aboveground and belowground net primary production

    Science.gov (United States)

    Marianne K. Burke; Hal O. Liechty; Mark H. Eisenbies

    2000-01-01

    The relationship among net primary productivity (NPP), hydroperiod, and fertility in forested wetlands is poorly understood (Burke and others 1999), particularly with respect to belowground NPP (Megonigal and others 1997). Although some researchers have studied aboveground and belowground primary production in depressional, forested wetland systems, e.g., Day and...

  4. [Estimation of aboveground biomass of desert plants].

    Science.gov (United States)

    Zhao, Chengyi; Song, Yudong; Wang, Yuchao; Jiang, Pinan

    2004-01-01

    Based on the research of plant quadrate in Sangong River Basin in Xinjiang, the fitted equations were given, which could be used to estimate the aboveground biomass of typical desert plant by using the thicket characteristics such as length of crown diameter, width of crown diameter, number of basal branch, length of new branch, basal diameter (D) and plant height (H) as parameters. Using the length of crown diameter and the width of crown diameter as parameters, the fitted equation was set up and tested for estimating the aboveground biomass of Reaumuria soongorica Maxim. It had a relatively high accuracy and a fine linear relationship between the predicted values and measured values. Its coefficient and relative standard deviation was 0.9989 and 4.79%-10.12%, respectively. The results indicated that the fitted equation was easy and available for estimating the aboveground biomass of Reaumuria soongorica Maxim in large scale. The fitted equations were also set up and tested for estimating the aboveground biomass of Haloxylon ammodendron and Tamarix ramosissima by using the basal diameter and height of plant as the parameters. The coefficients and relative standard deviations of these equations were 0.9902, 0.9875 and 6.87%-19.22%, 7.49%-18.47%, respectively. Therefore, estimating the biomass of Reaumuria soongorica in large scale through crown characteristics was available, and estimating the biomass of Halaxylon Ammodendron and Tamarix ramosissima through crown characteristics would produce certain error.

  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.

  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

    be quite tedious, and therefore a method to generate and optimize solutions has been developed and implemented in a program that also takes into account the effects of different types of thermal bridges, i.e. roof windows, insulation fasteners, roof/wall joints etc. This paper describes a new method...... for design of flat roofs and a pc-program that can be used for calculating the total heat loss coefficient of externally insulated roofs with insulation in tapered layers, taking into account thermal bridges in the roof construction....

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

    Directory of Open Access Journals (Sweden)

    Jeremy Lundholm

    Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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

  8. Linking evapotranspiration to stormwater reduction and attenuation in green roofs in Calgary, Alberta

    Science.gov (United States)

    Breach, P. A.; Robinson, C. E.; Voogt, J. A.; Smart, C. C.; O'Carroll, D. M.

    2013-12-01

    Green roofs have been used for centuries to insulate buildings and beautify urban environments. European countries, especially Germany, have adopted green roofs use in modern buildings, helping raise awareness of their many potential benefits. Green roofs have been shown to: effectively reduce and filter stormwater thereby decreasing the burden on urban sewer systems; provide insulation and lower roof surface temperature leading to a decrease in building energy load and reduced sensible heat flux to the urban atmosphere; and to extend the life of a roof by decreasing the temperature fluctuations which cause roof damage. Given that green buildings can mitigate against the negative impacts of storm water runoff and reduce the heating and cooling demands, use of green roofs in Canada might prove extremely beneficial due to our intense climate. However, the implementation of green roofs in North American urban environments remains underused, in part due to a lack of climate appropriate green roof design guidelines that are supported by scientific understanding of their performance in North American climates. The capacity of a green roof installation to moderate runoff depends on the storage capacity of the rooting medium at the start of the rainfall event which in turn is constrained by roof loading. The influence of medium depth is investigated through comparison to 15 cm and 10cm deep planting modules. Storage capacity has a finite limit, making rapid drainage and evapotranspiration loss essential to restore the retardation of a subsequent storm. Sustaining live plant cover requires avoidance of saturated conditions and retention of minimum soil moisture levels. These limits constrain the design options with distinctive climatic stresses. Here the performance of experimental green roof modules is investigated under particularly high climatic stressing at Calgary Alberta Canada. 10 cm modules show rapid drying to unacceptably low residual moisture content, whereas 15

  9. Empirically Derived Strength of Residential Roof Structures for Solar Installations.

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, Stephen F.; Sanchez, Alfred; Campos, Ivan A.; Gerstle, Walter H.

    2014-12-01

    Engineering certification for the installation of solar photovoltaic (PV) modules on wood roofs is often denied because existing wood roofs do not meet structural design codes. This work is intended to show that many roofs are actually sufficiently strong given the conservatism in codes, documented allowable strengths, roof structure system effects, and beam composite action produced by joist-sheathing interaction. This report provides results from a testing program to provide actual load carrying capacity of residential rooftops. The results reveal that the actual load carrying capacity of structural members and systems tested are significantly stronger than allowable loads provided by the International Residential Code (IRC 2009) and the national structural code found in Minimum Design Loads for Buildings and Other Structures (ASCE 7-10). Engineering analysis of residential rooftops typically ignores the system affects and beam composite action in determining rooftop stresses given a potential PV installation. This extreme conservatism combined with conservatism in codes and published allowable stress values for roof building materials (NDS 2012) lead to the perception that well built homes may not have adequate load bearing capacity to enable a rooftop PV installation. However, based on the test results presented in this report of residential rooftop structural systems, the actual load bearing capacity is several times higher than published values (NDS 2012).

  10. Roof selection for rainwater harvesting: quantity and quality assessments in Spain.

    Science.gov (United States)

    Farreny, Ramon; Morales-Pinzón, Tito; Guisasola, Albert; Tayà, Carlota; Rieradevall, Joan; Gabarrell, Xavier

    2011-05-01

    Roofs are the first candidates for rainwater harvesting in urban areas. This research integrates quantitative and qualitative data of rooftop stormwater runoff in an urban Mediterranean-weather environment. The objective of this paper is to provide criteria for the roof selection in order to maximise the availability and quality of rainwater. Four roofs have been selected and monitored over a period of 2 years (2008-2010): three sloping roofs - clay tiles, metal sheet and polycarbonate plastic - and one flat gravel roof. The authors offer a model for the estimation of the runoff volume and the initial abstraction of each roof, and assess the physicochemical contamination of roof runoff. Great differences in the runoff coefficient (RC) are observed, depending mostly on the slope and the roughness of the roof. Thus, sloping smooth roofs (RC>0.90) may harvest up to about 50% more rainwater than flat rough roofs (RC=0.62). Physicochemical runoff quality appears to be generally better than the average quality found in the literature review (conductivity: 85.0 ± 10.0 μS/cm, total suspended solids: 5.98 ± 0.95 mg/L, total organic carbon: 11.6 ± 1.7 mg/L, pH: 7.59 ± 0.07 upH). However, statistically significant differences are found between sloping and flat rough roofs for some parameters (conductivity, total organic carbon, total carbonates system and ammonium), with the former presenting better quality in all parameters (except for ammonium). The results have an important significance for local governments and urban planners in the (re)design of buildings and cities from the perspective of sustainable rainwater management. The inclusion of criteria related to the roof's slope and roughness in city planning may be useful to promote rainwater as an alternative water supply while preventing flooding and water scarcity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. 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...

  12. High Efficiency Solar Integrated Roof Membrane Product

    Energy Technology Data Exchange (ETDEWEB)

    Partyka, Eric; Shenoy, Anil

    2013-05-15

    This project was designed to address the Solar Energy Technology Program objective, to develop new methods to integrate photovoltaic (PV) cells or modules within a building-integrated photovoltaic (BIPV) application that will result in lower installed cost as well as higher efficiencies of the encapsulated/embedded PV module. The technology assessment and development focused on the evaluation and identification of manufacturing technologies and equipment capable of producing such low-cost, high-efficiency, flexible BIPV solar cells on single-ply roofing membranes.

  13. 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.

  14. The Effects of Infrared-Blocking Pigments and Deck Venting on Stone-Coated Metal Residential Roofs

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William A [ORNL

    2006-01-01

    Field data show that stone-coated metal shakes and S-mission tile, which exploit the use of infraredblocking color pigments (IrBCPs), along with underside venting reduce the heat flow penetrating the conditioned space of a residence by 70% compared with the amount of heat flow penetrating roofs with conventional asphalt shingles. Stone-coated metal roof products are typically placed on battens and counter-battens and nailed through the battens to the roof deck. The design provides venting on the underside of the metal roof that reduces the heat flow penetrating a home. The Metal Construction Association (MCA) and its affiliate members installed stone-coated metal roofs with shake and S-mission tile profiles and a painted metal shake roof on a fully instrumented attic test assembly at Oak Ridge National Laboratory (ORNL). Measurements of roof, deck, attic, and ceiling temperatures; heat flows; solar reflectance; thermal emittance; and ambient weather were recorded for each of the test roofs and also for an adjacent attic cavity covered with a conventional pigmented and direct nailed asphalt shingle roof. All attic assemblies had ridge and soffit venting; the ridge was open to the underside of the stone-coated metal roofs. A control assembly with a conventional asphalt shingle roof was used for comparing deck and ceiling heat transfer rates.

  15. Sloped Roof Conversions for Small, Flat-Roof Buildings.

    Science.gov (United States)

    1984-12-01

    co solve other, unrelated Table 5 List of Contacts Involved in Roof Conversion Projects California AEP-Span, San Diego Florida Duval County...Survlvablllty Section, CCB-CPS Infrastructure Branch, LANDA HQ UsaUCOH 09128 ATTN: ECJ 4/7-LOE Fort Belvoir, VA 22060 (7) ATTN

  16. 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...

  17. 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

  18. 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...

  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.

  20. Integrated Green Roofs System and its Role of Achieving Sustainability in Residential Buildings in Urban Area in Athens, Greece and Famagusta, North Cyprus

    Directory of Open Access Journals (Sweden)

    Seyed Mehran shahidipour

    2014-06-01

    Full Text Available In this paper, the characteristics and importance of the green roof in urban area would investigate in some residential buildings in Athens, Greece and then, some strategies give to integrate green roof in residential buildings in Famagusta, north Cyprus due to the importance of energy saving and thermal comfort in residential buildings. These days, sustainable architecture is spreading around the world. Therefore, Sustainable architecture has important role in design buildings and urban design due to high amount of energy use and global warming around the world. There are different methods in sustainable design and one of them that has significant role is design green roof. Green roof integrated to the roof of the buildings to provide the suitable indoor temperature without spending high amount of budget. The methodology is qualitative type that trough the literature review and survey would be understood the importance and role of the green roof in both architecture and urban area. There are many significant architects like Wright that they understood how greenery would improve the function of the building in terms of provide thermal comfort and indoor temperature for the residences, and green roof as well. In Famagusta, there is not any green roof however, the design and integrating of green roof is inexpensive. Green roof should design properly depend on the characteristic of the climate of every place so, the location, temperature, and humidity, location, and wind have influence on the design of the green roof.

  1. A parametric study of the thermal performance of green roofs in different climates through energy modeling

    Science.gov (United States)

    Mukherjee, Sananda

    In recent years, there has been great interest in the potential of green roofs as an alternative roofing option to reduce the energy consumed by individual buildings as well as mitigate large scale urban environmental problems such as the heat island effect. There is a widespread recognition and a growing literature of measured data that suggest green roofs can reduce building energy consumption. This thesis investigates the potential of green roofs in reducing the building energy loads and focuses on how the different parameters of a green roof assembly affect the thermal performance of a building. A green roof assembly is modeled in Design Builder- a 3D graphical design modeling and energy use simulation program (interface) that uses the EnergyPlus simulation engine, and the simulated data set thus obtained is compared to field experiment data to validate the roof assembly model on the basis of how accurately it simulates the behavior of a green roof. Then the software is used to evaluate the thermal performance of several green roof assemblies under three different climate types, looking at the whole building energy consumption. For the purpose of this parametric simulation study, a prototypical single story small office building is considered and one parameter of the green roof is altered for each simulation run in order to understand its effect on building's energy loads. These parameters include different insulation thicknesses, leaf area indices (LAI) and growing medium or soil depth, each of which are tested under the three different climate types. The energy use intensities (EUIs), the peak and annual heating and cooling loads resulting from the use of these green roof assemblies are compared with each other and to a cool roof base case to determine the energy load reductions, if any. The heat flux through the roof is also evaluated and compared. The simulation results are then organized and finally presented as a decision support tool that would

  2. 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.

  3. The Girl on the Roof

    Institute of Scientific and Technical Information of China (English)

    刘晓宁; 邓彬

    2003-01-01

    One day when the sun was shin-ning and Jillian's office at the BBCwas getting warm,she had one of her ideas."I'll go up ontothe roof after lunch,"she thought,"andsunbathe(日光浴).I've been working hard

  4. 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.

  5. 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.

  6. Hydrological Response of Sedum-Moss Roof

    Science.gov (United States)

    Bengtsson, L.

    2004-12-01

    Eco-roofs are becoming popular for aesthetic reasons and also as units of stormwater systems. It is thought that such roofs with soil cover and vegetation reduces the total runoff, the peak flows and improves the quality of the roof water. Here are reported investigations of runoff from thin, 3-4 cm soil, extensive green roofs with sedum-moss in southern Sweden. The two-year study was performed on new roofs in the eco-city Augustenborg and also on nearby old vegetative roofs. The rain intensity and the roof runoff were measured with 5 min, or in some experiments with 1 min, resolution. The annual runoff from the eco-roofs was about half that from hard roofs and was close to that of small natural rivers. However, although most rainy days there was no or little runoff from the roofs, the highest observed daily runoff values were close to the daily rainfall. Runoff is initiated, when the soil is at field capacity. Thereafter the hourly runoff corresponds closely to the hourly rainfall. For short-term high intensity storms, the runoff peak is attenuated relative the rain intensity. The time of concentration for runoff was experimentally determined applying artificial rains on existing roofs and on experimental roof plots with varying slopes and using different drainage layers. The peak runoff from the roofs was found to correspond to the rain intensity over 20-30 minutes. The probability of high rain intensity is much higher than the probability of high runoff. When intensity-duration-frequency curves were constructed, runoff with 0.4 year return period corresponded to rain with 1.5 year return period. The influence of the slope of the roofs on the runoff peak was minor as was the effect of drainage layer. The vertical flow in the soil dominates the runoff process. The influence of extensive sedum-moss vegetated roofs on runoff quality was also studied to ascertain whether vegetated roofs behave as sink or source of pollutants and whether the runoff quality changes

  7. 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…

  8. 40 CFR 65.44 - External floating roof (EFR).

    Science.gov (United States)

    2010-07-01

    ... Section 65.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Storage Vessels § 65.44 External floating roof (EFR). (a) EFR design requirements. The owner or operator who elects to control storage vessel regulated material...

  9. PREDICTING THERMAL PERFORMANCE OF ROOFING SYSTEMS IN SURABAYA

    OpenAIRE

    2015-01-01

    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 Sura...

  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. Use of green roofs for ultra-urban stream restoration in the Georgia Piedmont, USA

    Energy Technology Data Exchange (ETDEWEB)

    Carter, T. [Georgia Univ., Athens, GA (United States). Inst. of Technology; Rasmussen, T.C. [Georgia Univ., Athens, GA (United States). Warnell School of Forest Resources

    2005-07-01

    As a result of clean water acts in the United States, stormwater permits are required for local governments that are designed to reduce impacts on receiving water bodies. Elevated runoff volumes and rates lead to high pollutant transfer and altered hydrology. Best management practices (BMP) for stormwater include porous pavements, bioretention ponds and vegetated swales. Green roofs have been overlooked as a tool for managing stormwater. This study tested vegetated roof plots at the University of Georgia for their effectiveness in reducing stormwater flows. Two test sites were retrofitted onto an existing flat roof at a site on the university campus. A control plot was used to validate the green roof performance. Storm events were continuously monitored for a 1 year period. Flow was calculated based on the width of the orifice and the height of the water. Detailed spatial analysis was then performed in an urban watershed to determine the effect of widespread green roof implementation using a soil conservation service curve number model. Green roof curve numbers were found for 11 storm events. Composite curve numbers were established for different scenarios to model changes in stormwater volume for existing land cover, the greening of all roofs, and the greening of all flat roofs. Results showed that green roof stormwater retention ranged from 39 to 100 per cent. It was concluded that green roofs alone cannot solely be relied on to provide the minimum recommended stormwater management at the watershed scale. Green roofs must be used with other management strategies in a comprehensive watershed management plan if effective rehabilitation is to be considered. 14 refs., 2 tabs., 5 figs.

  12. Life-cycle cost-benefit analysis of extensive vegetated roof systems.

    Science.gov (United States)

    Carter, Timothy; Keeler, Andrew

    2008-05-01

    The built environment has been a significant cause of environmental degradation in the previously undeveloped landscape. As public and private interest in restoring the environmental integrity of urban areas continues to increase, new construction practices are being developed that explicitly value beneficial environmental characteristics. The use of vegetation on a rooftop--commonly called a green roof--as an alternative to traditional roofing materials is an increasingly utilized example of such practices. The vegetation and growing media perform a number of functions that improve environmental performance, including: absorption of rainfall, reduction of roof temperatures, improvement in ambient air quality, and provision of urban habitat. A better accounting of the green roof's total costs and benefits to society and to the private sector will aid in the design of policy instruments and educational materials that affect individual decisions about green roof construction. This study uses data collected from an experimental green roof plot to develop a benefit cost analysis (BCA) for the life cycle of extensive (thin layer) green roof systems in an urban watershed. The results from this analysis are compared with a traditional roofing scenario. The net present value (NPV) of this type of green roof currently ranges from 10% to 14% more expensive than its conventional counterpart. A reduction of 20% in green roof construction cost would make the social NPV of the practice less than traditional roof NPV. Considering the positive social benefits and relatively novel nature of the practice, incentives encouraging the use of this practice in highly urbanized watersheds are strongly recommended.

  13. 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.

  14. 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.

  15. 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 %.

  16. Development and integration of a green roof model within whole building energy simulation

    OpenAIRE

    Decruz, Aloysius

    2016-01-01

    Green roofs are increasingly being employed as a sustainability feature of buildings. The sustainability approach in building designs requires reducing energy consumption and adopting low carbon energy sources without compromising the increasing expectations of comfort and health levels. Given the wide range of building designs, climates and green roof types, it is desirable to evaluate at the design stage the energy saving impact and other potential benefits from the application of green roo...

  17. 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...... the centre-pivot roof window can be characterised by a factor called the flow factor. The flow factor was a function of the sash opening-angle and wind direction. The flow factor increased with increase in opening-angle and decreased with increase in wind direction....

  18. 华南地区屋顶菜园工程设计与建造技术研究%The Design and Construction of Urban Roof Vegetable Garden in South China

    Institute of Scientific and Technical Information of China (English)

    董斌; 林国雄; 易弦; 查钱慧; 洪文泓

    2015-01-01

    Urban roof vegetable garden originated from roof garden. Based on the development of urban roof vegetable garden in South China , the thesis takes the constrcutions and experiments with vegetables in Guangdong Agriculture Industry Business Polytechnic College as example , sums up a practical and key technique of urban roof vegetable garden in South China through researching the function division, variety selection, roof structure, load bearing, water supply and drainage, wind-proof technique so as to do some foundation works for constructions and developments of roof vegetable garden in the future.%城市屋顶菜园是在屋顶花园基础上衍生的新兴产物。结合华南地区屋顶菜园的建设现状,以广东农工商职业技术学院屋顶菜园工程建造和蔬菜适生性试验为例,从功能分区、适种品种、屋面结构、承重荷载、给排水技术、防风技术等层面入手,归纳出一套适宜华南地区屋顶菜园设计及建造的关键技术,以期为该区域屋顶菜园建设和发展做一些基础性工作。

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

    Institute of Scientific and Technical Information of China (English)

    Jamal Rostami; Sair Kahraman; Ali Naeimipour; Craig Collins

    2015-01-01

    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 in-formation 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 sug-gested improvements are also discussed.

  20. 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.

  1. 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

  2. Wind tunnel tests for wind pressure distribution on gable roof buildings.

    Science.gov (United States)

    Jing, Xiao-kun; Li, Yuan-qi

    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.

  3. 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.

  4. 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.

  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. Choosing the right green roof media for water quality

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, W.F.; Hathaway, A.M.; Smith, J.T.; Calabria, J. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Biological and Agricultural Engineering

    2006-07-01

    Due to the large concentrations of a variety of contaminants entering streams and rivers, stormwater is a significant contributor to the impairment of North Carolina (NC) waters. Pollutants range from pesticides and nutrients to oils and petroleum products to construction chemicals and sediment which are evident in fish kills, contamination of drinking water supplies, and deterioration of wildlife habitats. One of the major tools to improve storm water quality are stormwater best management practices (BMPs). BMPs include bioretention areas, wet and dry detention ponds, constructed wetlands, and sand filters. One option for urban BMPs is the green roof which uses rooftop square footage that would not otherwise be available on the ground. A research project was conducted that tests two field green roofs in Raleigh and Asheville, NC. In addition, a laboratory test was conducted in 2004 and a plot study of three designer media was conducted in 2005 on the NC State University Campus in Raleigh, NC. The objectives of the research were to examine how different green roof media reduce concentrations of nitrogen and phosphorus, if the leaching rate of nitrogen and phosphorus from soil media of field green roofs decrease with time, and to determine whether green roofs can be used as nutrient reduction BMPs. This paper provided background information on previous green roof stormwater research, discussed each of the sites chosen for the study in detail and presented the field monitoring process and laboratory study methodology. This was followed by a detailed examination of the results. It was concluded that an optimal soil media can be established that balances plant growth with water quality and quantity control. 16 refs., 2 tabs., 8 figs.

  7. 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

  8. Evaluating convex roof entanglement measures.

    Science.gov (United States)

    Tóth, Géza; Moroder, Tobias; Gühne, Otfried

    2015-04-24

    We show a powerful method to compute entanglement measures based on convex roof constructions. In particular, our method is applicable to measures that, for pure states, can be written as low order polynomials of operator expectation values. We show how to compute the linear entropy of entanglement, the linear entanglement of assistance, and a bound on the dimension of the entanglement for bipartite systems. We discuss how to obtain the convex roof of the three-tangle for three-qubit states. We also show how to calculate the linear entropy of entanglement and the quantum Fisher information based on partial information or device independent information. We demonstrate the usefulness of our method by concrete examples.

  9. 机库钢屋盖结构整体提升专项方案设计%Plan Design of the Integral Elevation of Steel Truss Roof Structure of the Hangar

    Institute of Scientific and Technical Information of China (English)

    李慧慧

    2016-01-01

    This paper takes integral elevation construction of the steel truss roof structure of a hangar as the example to mainly introduce the technological principle of the synchronous overall elevation technique of the grid structure, arraignment plan design and the main construction process of the elevation. At the same time, the finite element analysis software MIDAS/Gen V8.2.0 is used to carry out the simulation analysis to ensure the quality and safety of the elevation engineering.%以某机库钢网架屋盖整体提升工程为例,重点介绍了网架结构同步整体提升技术的技术原理、提审方案设计、提升的重点施工工艺,同时应用有限元分析软件程序MIDAS/Gen V8.2.0仿真分析,以确保提升工程的质量和安全.

  10. 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.

  11. Future oriented and more sustainable green roofs

    Energy Technology Data Exchange (ETDEWEB)

    Appl, R.; Ansel, W. [Deutscher Dachgartnerverband, Nuertingen (Germany)

    2004-07-01

    The contribution that green roofs make to sustainable urban Development were discussed with reference to the support that the industry has received in Germany. The German Roof Gardener Association (DDV) was established in the 1990s with an objective to replace the billions of square feet of bare or gravel flat roof surface area in Germany with ecological green roofs. The DDV created guidelines for the systems and components being used in green roof constructions, starting from the raw material to the production and transport of the material, and to the recycling of the material after demolition. Green roofs in Germany are now made mandatory by local authorities. Green roofs offer innovative technological features as well as additional use. Combined with extensive or intensive greening, these roofs reduce the use of building land. They must be built to last the lifetime of the building and given proper care and maintenance. In the twenty-first century, green roof systems will be made of recycled and environmentally sound material. The purpose of the green roof is to provide not only a permanent location for vegetation, but also offer further possibilities of utilization, such as additional thermal insulation, fall protection systems or even constructions for solar power facilities. This paper addressed issues regarding the extended life expectancy of a roof, savings on stormwater tax and thermal values for insulation calculations. Green roofs in Germany currently represent an important element in stormwater management by slowing down, filtering and diminishing rain water runoff. The excess water is guided into cisterns and used for the irrigation of the roof gardens and for flushing toilets. 5 figs.

  12. Roof Polishing of Optical Fibers

    Science.gov (United States)

    Dholakia, A. R.

    1985-01-01

    Bevealed tip gives optimum coupling efficiency. Abrasive tape used to grind tip of optical fiber. Grinding force depends on stiffness of optical fiber. "Roof" shape on end of optical glass fiber increases efficiency which couples laser light. End surface angle of 65 degrees with perpendicular required for optimum coupling. Since fiber and tape are light in weight and compliant, ridge defect-free, and chipping on fiber edge totally eliminated.

  13. The Trade-off between Solar Reflectance and Above-Sheathing Ventilation for Metal Roofs on Residential and Commercial Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Desjarlais, Andre Omer [ORNL; Kriner, Scott [Metal Construction Association, Glenview, IL; Miller, William A [ORNL

    2013-01-01

    An alternative to white and cool-color roofs that meets prescriptive requirements for steep-slope (residential and non-residential) and low-slope (non-residential) roofing has been documented. Roofs fitted with an inclined air space above the sheathing (herein termed above-sheathing ventilation, or ASV), performed as well as if not better than high-reflectance, high-emittance roofs fastened directly to the deck. Field measurements demonstrated the benefit of roofs designed with ASV. A computer tool was benchmarked against the field data. Testing and benchmarks were conducted at roofs inclined at 18.34 ; the roof span from soffit to ridge was 18.7 ft (5.7 m). The tool was then exercised to compute the solar reflectance needed by a roof equipped with ASV to exhibit the same annual cooling load as that for a direct-to-deck cool-color roof. A painted metal roof with an air space height of 0.75 in. (0.019 m) and spanning 18.7 ft (5.7 m) up the roof incline of 18.34 needed only a 0.10 solar reflectance to exhibit the same annual cooling load as a direct-to-deck cool-color metal roof (solar reflectance of 0.25). This held for all eight ASHRAE climate zones complying with ASHRAE 90.1 (2007a). A dark heat-absorbing roof fitted with 1.5 in. (0.038 m) air space spanning 18.7 ft (5.7 m) and inclined at 18.34 was shown to have a seasonal cooling load equivalent to that of a conventional direct-to-deck cool-color metal roof. Computations for retrofit application based on ASHRAE 90.1 (1980) showed that ASV air spaces of either 0.75 or 1.5 in. (0.019 and 0.038 m) would permit black roofs to have annual cooling loads equivalent to the direct-to-deck cool roof. Results are encouraging, and a parametric study of roof slope and ASV aspect ratio is needed for developing guidelines applicable to all steep- and low-slope roof applications.

  14. Defects and behaviour of inverted flat roof from the point of building physics

    Directory of Open Access Journals (Sweden)

    Misar Ivan

    2017-01-01

    Full Text Available One of the most discussed flat roof structures during the last 20 years is a structure called inverted roof, where the main thermal insulation layer is placed above the main waterproofing system. The reasons why this type of flat roof is or could be chosen are more less clear. Usually it is the intention to protect the main waterproofing system, usually of synthetic or bituminous membranes, against the impact of outdoor air thermal changes, against any prospective mechanical damages and also to reduce risk of water vapor condensation in the structure. This type of structure could help to solve the vapor/thermal difficulties during the design of the flat roof over the space with higher indoor air humidity like swimming pools or specific industrial processes. Due to the higher rate of safety against mechanical damage it is also used quite often in the case of the design of the roof terraces or roof gardens. Nevertheless, the correct attitude during the design of the structure is to take into considerations all possible aspects including the defects and problems which are most typical for each one type of structure. This paper is willing to give the brief overview of the typical defects for inverted flat roofs and to contribute a little to the understanding of commonly discussed effect of undergoing water beneath the thermal insulation itself and decreasing thus the thermal protection efficiency as well as the inner surface temperature.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Identifying fall-protection training needs for residential roofing subcontractors.

    Science.gov (United States)

    Hung, Yu-Hsiu; Winchester, Woodrow W; Smith-Jackson, Tonya L; Kleiner, Brian M; Babski-Reeves, Kari L; Mills, Thomas H

    2013-05-01

    Falls remain the leading cause of injuries and fatalities in the small residential roofing industry and analogous investigations are underrepresented in the literature. To address this issue, fall-protection training needs were explored through 29 semi-structured interviews among residential roofing subcontractors with respect to recommendations for the design of fall-protection training. Content analysis using grounded theory was conducted to analyze participants' responses. Results of the analysis revealed six themes related to the design of current fall-protection training: (1) barriers to safety training; (2) problems of formal safety-training programs; (3) recommendations for training implementation; (4) important areas for fall-protection training; (5) training delivery means; and (6) design features of training materials. Results of the study suggest the need for informal jobsite safety training to complement what had been covered in formalized safety training. This work also provides recommendations for the design of a more likely adopted fall-protection training program.

  20. 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...

  1. 49 CFR 195.307 - Pressure testing aboveground breakout tanks.

    Science.gov (United States)

    2010-10-01

    ... Standard 620 and first placed in service after October 2, 2000, hydrostatic and pneumatic testing must be... aboveground breakout tanks. (a) For aboveground breakout tanks built into API Specification 12F and first placed in service after October 2, 2000, pneumatic testing must be in accordance with section 5.3 of...

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

    Science.gov (United States)

    Zhao, Yiming; Zhang, Nong; Si, Guangyao

    2016-10-21

    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.

  3. 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.

  4. 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.

  5. 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.

  6. Orbital dystopia due to orbital roof defect.

    Science.gov (United States)

    Rha, Eun Young; Joo, Hong Sil; Byeon, Jun Hee

    2013-01-01

    We performed a retrospective review of patients who presented with delayed dystopia as a consequence of an orbital roof defect due to fractures and nontraumatic causes to search for a correlation between orbital roof defect size and surgical indications for the treatment thereof. Retrospective analyses were performed in 7 patients, all of whom presented with delayed dystopia due to orbital roof defects, between January 2001 and June 2011. The causes of orbital roof defects were displaced orbital roof fractures (5 cases), tumor (1 case), and congenital sphenoid dysplasia (1 case). All 7 patients had initially been treated conservatively and later presented with significant dystopia. The sizes of the defects were calculated on computed tomographic scans. Among the 7 patients, aspiration of cerebrospinal fluid, which caused ocular symptoms, in 1 patient with minimal displaced orbital roof and reconstruction with calvarial bone, titanium micromesh, or Medpor in 6 other patients were performed. The minimal size of the orbital roof in patients who underwent orbital roof reconstruction was 1.2 cm (defect height) x 1.0 cm (defect length), 0.94 cm(2). For all patients with orbital dystopia, displacement of the globe was corrected without any complications, regardless of whether the patient was evaluated grossly or by radiology. In this retrospective study, continuous monitoring of clinical signs and active surgical management should be considered for cases in which an orbital roof defect is detected, even if no definite symptoms are noted, to prevent delayed sequelae.

  7. Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models

    NARCIS (Netherlands)

    Johnson, Michelle O.; Galbraith, David; Gloor, Manuel; Deurwaerder, De Hannes; Guimberteau, Matthieu; Rammig, Anja; Thonicke, Kirsten; Verbeeck, Hans; Randow, Von Celso; Monteagudo, Abel; Phillips, Oliver L.; Brienen, Roel J.W.; Feldpausch, Ted R.; Lopez Gonzalez, Gabriela; Fauset, Sophie; Quesada, Carlos A.; Christoffersen, Bradley; Ciais, Philippe; Sampaio, Gilvan; Kruijt, Bart; Meir, Patrick; Moorcroft, Paul; Zhang, Ke; Alvarez-Davila, Esteban; Alves De Oliveira, Atila; Amaral, Ieda; Andrade, Ana; Aragao, Luiz E.O.C.; Araujo-Murakami, Alejandro; Arets, Eric J.M.M.; Arroyo, Luzmila; Aymard, Gerardo A.; Baraloto, Christopher; Barroso, Jocely; Bonal, Damien; Boot, Rene; Camargo, Jose; Chave, Jerome; Cogollo, Alvaro; Cornejo Valverde, Fernando; Lola Da Costa, Antonio C.; Fiore, Di Anthony; Ferreira, Leandro; Higuchi, Niro; Honorio, Euridice N.; Killeen, Tim J.; Laurance, Susan G.; Laurance, William F.; Licona, Juan; Lovejoy, Thomas; Malhi, Yadvinder; Marimon, Bia; Marimon, Ben Hur; Matos, Darley C.L.; Mendoza, Casimiro; Neill, David A.; Pardo, Guido; Peña-Claros, Marielos; Pitman, Nigel C.A.; Poorter, Lourens; Prieto, Adriana; Ramirez-Angulo, Hirma; Roopsind, Anand; Rudas, Agustin; Salomao, Rafael P.; Silveira, Marcos; Stropp, Juliana; Steege, Ter Hans; Terborgh, John; Thomas, Raquel; Toledo, Marisol; Torres-Lezama, Armando; Heijden, van der Geertje M.F.; Vasquez, Rodolfo; Guimarães Vieira, Ima Cèlia; Vilanova, Emilio; Vos, Vincent A.; Baker, Timothy R.

    2016-01-01

    Understanding the processes that determine aboveground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody

  8. THERMAL INFRARED INSPECTION OF ROOF INSULATION USING UNMANNED AERIAL VEHICLES

    Directory of Open Access Journals (Sweden)

    J. Zhang

    2015-08-01

    Full Text Available UAVs equipped with high-resolution thermal cameras provide an excellent investigative tool used for a multitude of building-specific applications, including roof insulation inspection. We have presented in this study a relative thermographic calibration algorithm and a superpixel Markov Random Field model to address problems in thermal infrared inspection of roof insulation using UAVs. The relative thermographic radiometric calibration algorithm is designed to address the autogain problem of the thermal camera. Results show the algorithm can enhance the contrast between warm and cool areas on the roof surface in thermal images, and produces more constant thermal signatures of different roof insulations or surfaces, which could facilitate both visual interpretation and computer-based thermal anomaly detection. An automatic thermal anomaly detection algorithm based on superpixel Markov Random Field is proposed, which is more computationally efficient than pixel based MRF, and can potentially improve the production throughput capacity and increase the detection accuracy for thermal anomaly detection. Experimental results show the effectiveness of the proposed method.

  9. 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.

  10. 青藏±400 kV格尔木换流站户内直流场厂房屋面结构型式论证%Designing of the Indoor DC Field Plant House Roof Structure at the ±400 kV Golmud Converter Station of Qinghai-Tibet Interconnection Project

    Institute of Scientific and Technical Information of China (English)

    王宁璧; 刘凯锋; 刘志声

    2012-01-01

    For different potential structure types for the indoor DC field plant house roof of the ±400 kV Golmud Converter Station Project, this paper makes comparisons and studies in terms of the forces exerted on the structure, the cost and construction schedule, etc and then proposes a roof structure both economical and feasible. This design can provide a reference to other similar.%通过对格尔木±400 kV换流站工程中户内直流场厂房屋面采用不同的结构型式,从结构受力、造价预算和施工工期等方面的分析比较,提出经济可行的屋面结构型式,为同行进行类似设计时提供参考.

  11. New bolting structure of fractured roof based on the Bossinesq equations

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Present support theories contain a number of shortcomings in the designation of fractured roof bolt parameters of rectangular or trapezoidal coal roadways.Roof fall accidents occur easily in this kind of roadway.Based on the Bossinesq equations and the Mohr strength theory,we propose a theory of an anchored cluster structure for fractured roofs and have investigated the formation of such an anchored cluster structure,its self stability mechanism and mechanical properties.The results show that an anchor and ...

  12. 4 Living roofs in 3 locations: Does configuration affect runoff mitigation?

    Science.gov (United States)

    Fassman-Beck, Elizabeth; Voyde, Emily; Simcock, Robyn; Hong, Yit Sing

    2013-05-01

    Four extensive living roofs and three conventional (control) roofs in Auckland, New Zealand have been evaluated over periods of 8 months to over 2 yrs for stormwater runoff mitigation. Up to 56% cumulative retention was measured from living roofs with 50-150 mm depth substrates installed over synthetic drainage layers, and with >80% plant coverage. Variation in cumulative %-retention amongst sites is attributed to different durations of monitoring, rather than actual performance. At all sites, runoff rarely occurred at all from storms with less than 25 mm of precipitation, from the combined effects of substrates designed to maximize moisture storage and because >90% of individual events were less than 25 mm. Living roof runoff depth per event is predicted well by a 2nd order polynomial model (R2 = 0.81), again demonstrating that small storms are well managed. Peak flow per event from the living roofs was 62-90% less than a corresponding conventional roof's runoff. Seasonal retention performance decreased slightly in winter, but was nonetheless substantial, maintaining 66% retention at one site compared to 45-93% in spring-autumn at two sites. Peak flow mitigation did not vary seasonally. During a 4-month period of concurrent monitoring at all sites, varied substrate depth did not influence runoff depth (volume), %-retention, or %-peak flow mitigation compared to a control roof at the same site. The magnitude of peak flow was greater from garden shed-scale living roofs compared to the full-scale living roofs. Two design aspects that could be manipulated to increase peak flow mitigation include lengthening the flow path through the drainage layer to vertical gutters and use of flow-retarding drainage layer materials.

  13. 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

    2017-02-06

    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.

  14. 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 a

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

    Energy Technology Data Exchange (ETDEWEB)

    Posta, B.A.; Kadar, I. [Bechtel Corp., San Francisco, CA (United States); Rao, A.S. [General Electric Nuclear Engineering, San Jose, CA (United States)

    1996-07-01

    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.

  16. 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.

  17. Experimental polyurethane foam roof systems, part 2

    Science.gov (United States)

    Alumbaugh, R. L.; Keeton, J. R.; Humm, E. F.

    1983-01-01

    An experimental roofing installation is described in which polyurethane foam (PUF) was spray-applied directly to metal Butlerib-type metal decks, the roof divided into five approximately equal areas, and the PUF protected with five different elastomeric coating systems. Three of the coating systems were damaged by hailstones about a year after installation; these systems were recoated within 3 years of the initial installation. The current coatings include two of the original coating systems - a plural component silicone and a single component silicone - and those applied over the three systems damaged by hail - a single component silicone, an aluminum filled, hydrocarbon-extended catalyzed urethane, and a catalyzed urethane. The performance of these five PUF systems over a 7-year period is reported. The temperature distributions throughout the roof systems are described. The decay in the thermal conductivity of the PUF roof over a 5-year period is presented, and the energy savings realized by foaming the roof are presented.

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

    Science.gov (United States)

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

    2011-01-01

    Background and Aims 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. Methods 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. Key Results 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. Conclusions 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

  19. 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.

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

    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 compartida Open 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

  1. 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

  2. The Tajik People: Crown on the Roof of the World

    Institute of Scientific and Technical Information of China (English)

    GuBingshu

    2004-01-01

    The Tajiks reside in relative isolation in the snow-capped Pamir Mountain range of West China near the borders of Afghanistan, Pakistan and Russia. The Pamir mountains, known as the “roof of the world”, surround this specially designated Tajik district in three directions, and a desert borders the region on the fourth. The largest concentration of Tajik people live on the edge of Tashkorgan,

  3. Unique Roll-Off Roof for Housing 1.3 m Telescope at Devasthal, Nainital

    Science.gov (United States)

    Bangia, Tarun

    2017-06-01

    Aryabhatta Research Institute of Observational Sciences (ARIES) had set up a 1.3 m telescope at Devasthal, Nainital, India in the year 2010. Country's largest roll-off roof was indigenously designed, fabricated and installed on top of a building (17 × 8 m) for housing 1.3 m telescope. Telescope was supplied by M/s DFM Engineering Inc., USA to ARIES and was installed in the building with unique roll-off roof to protect it from external environment. Roll-off roof was designed and fabricated considering various parameters and available manpower and resources at ARIES. This paper presents mechanical development work, simple but distinct design approach and innovative selection of materials to economically manufacture roll-off roof of large size (8 × 8 × 4 m) at hilly remote site of Devasthal situated in Central Himalayan region. All operations in the roof viz. opening of shutters and rolling of roof were motorized to facilitate observers during night observations.

  4. 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.

  5. Solar roof Spansko-Croatia

    Energy Technology Data Exchange (ETDEWEB)

    Majdandzic, L. [Croatian Professional Society for Solar Energy, Zagreb (Croatia); Peric, M. [Brodarski Institute, Zagreb (Croatia); Matic, Z. [Hrvoje Pozar Energy Institute, Zagreb (Croatia)

    2004-07-01

    This paper presents a project named ''Solar roof Spansko-Zagreb'' with data for half a year of operation. This is the first grid-connected project in the Republic of Croatia. The project comprises of solar collectors providing thermal energy, and of PV modules providing electricity. This building does not emit carbon dioxide into the environment, a major contributor of global warming. The concept shows that passive and active use of solar energy can meet power needs of a building, without disrupting the comfort of habitation. The building reduces consumption of fossil fuels thus reducing the emission of harmful substances into the environment. This project represents an initiative for increased use of solar energy, especially on islands in coastal region and hinterland of Croatia. (orig.)

  6. City of Seattle green roof policy development through extended performance monitoring as a basis for hydrologic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Wachter, H.M.; Berkompas, B.; Taylor, W.; Marx, K.W. [Taylor Associates, Inc., Seattle, WA (United States); Lilly, D. [City of Seattle, Seattle Public Utilities, Seattle, WA (United States)

    2007-07-01

    The advantages offered by green roofs range from improvement in architectural and landscape aesthetics to reductions in building energy costs. Seattle Public Utilities (SPU) is encouraging sustainable community development through new policies and regulations that promote green roof installation on public and commercial rooftops in Seattle's urban center. An understanding of climate-specific green roof performance is required in order to develop an accurate representation of the stormwater benefits of green roofs. This paper explored the relative importance of green roofs in storm water management and low impact development (LID) in various areas of Seattle. It also examined the relative effectiveness and applicability of green roofs under various conditions and in various parts of the city compared to other LID strategies such as Seattle's natural drainage systems (NDS) designs, swales and ponds, rain gardens, rainwater harvesting, and porous pavements. SPU has launched a research program led by Taylor Associates, a Seattle aquatic sciences consulting firm, to monitor the rainfall, evapotranspiration, soil storage, and runoff on several existing green roofs over a three year period. In particular, the city is interested in identifying LID features that, independently or in combination with other strategies, effectively attenuate peak flows to potentially reduce combined sewer overflow (CSO) events. Long-term hydrologic records will be used to calibrate a continuous hydrologic model to enable the simulation of green roof performance based on a 40-year rainfall record. The objective of this effort is to use long-term simulation as a basis for policy development regarding the use of green roofs. Future funding may expand the study to investigate the benefit that green roofs may provide for roof runoff water quality in Seattle's most urban areas. 23 refs., 2 tabs., 3 figs.

  7. 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.

  8. Free Vibration of Laminated Composite Hypar Shell Roofs with Cutouts

    Directory of Open Access Journals (Sweden)

    Sarmila Sahoo

    2011-01-01

    Full Text Available Use of laminated composites in civil engineering structural components including shell roofs is increasing day by day due to their light weight, high specific strength, and stiffness properties. In the present paper, laminated composite hypar shell (hyperbolic paraboloidal shells bounded by straight edges roofs with cutouts are analyzed for their free vibration characteristics using finite element method. An eight-noded curved shell element is used for modeling the shell. Specific numerical problems of earlier investigators are solved to compare their results with the present formulation. A number of problems are further solved where the size of the cutouts and their positions with respect to the shell centre are varied for different edge constraints. The results are furnished in the form of figures and tables. The results are examined thoroughly to arrive at some meaningful conclusions useful to designers.

  9. STUDY ON HARD ROOF ROCKBURST IN COAL MINE

    Institute of Scientific and Technical Information of China (English)

    潘一山; 陈德军; 章梦涛

    1997-01-01

    Based on practical observation in Mentougou Mine, a general law of roof rockburst is put forward. The destabilization theory of roof rockburst has been established. The general laws of microquake premonition and earth sound in roof rockburst is advanced. The relationship between roof rockburst and rockburst of coal body is studied.

  10. Analysis on thermal measuring of green roof

    Institute of Scientific and Technical Information of China (English)

    唐鸣放; 蒋琳

    2009-01-01

    Comparison of thermal performance between a green roof room and a bare roof room was presented during the cooling period in Shanghai. The results show that the electricity can be saved about 0.08 kW·h/(d·m2),and the heat flux can be reduced by about 70%; the inner surface temperature variation is about 1.0 ℃ comparing with the indoor temperature when using the green roof,and the extra equivalent heat resistance is 1.0 m2·K/W.

  11. 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.

  12. Innovative Ballasted Flat Roof Solar PV Racking System

    Energy Technology Data Exchange (ETDEWEB)

    Peek, Richard T.

    2015-01-23

    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.

  13. 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.

  14. 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].

  15. Hydrologic Restoration in the Urban Environment Using Green Roofs

    OpenAIRE

    Anna Palla; Ilaria Gnecco; Luca G. Lanza

    2010-01-01

    Loss of natural soil and vegetation within the urban environment can significantly affect the hydrologic cycle by increasing storm water runoff rates and volumes. In order to mitigate these modifications in urban areas engineered systems are developed, such as green roofs, to mimic and replace functions (evapo-transpiration, infiltration, percolation) which have been altered due to the impact of human development. Green roofs, also known as vegetated roof covers, eco-roofs or nature roofs, ar...

  16. Building Integrated Photovoltaic (BIPV) Roofs for Sustainability and Energy Efficiency

    Science.gov (United States)

    2014-04-01

    conventional dark roofs, but the degradation in the first few years was significant. This was primarily due to soiling and not actual roof membrane... degradation . Since roof cleaning is not a typical DoD operations or maintenance activity, roof reflectivity was measured with the soiling during the...Roof albedo was originally planned to be measured for only Site III (MCAS Yuma), but since there were different soiling /aging/ degradation conditions

  17. Improving the durability of flat roof constructions

    DEFF Research Database (Denmark)

    Rudbeck, Claus Christian; Svendsen, Sv Aa Højgaard

    1999-01-01

    Flat roof constructions are mainly used on commercial, institutional and industrial buildings, where insulation is placed on top of the load-bearing deck and then covered with a roof membrane. Through time, there is a risk that the membrane will allow water passage as holes might form due...... as there is no easy method of drying it. To be able to dry the insulation, and thereby regain the functional requirements of the roofing system, two new solutions for insulating flat roofs with existing materials are proposed for high density mineral wool and expanded polystyrene. Monitoring equipment are part...... to weathering effects or physical loads. Water will then enter the insulation, and as a vapor retarder is normally found below the insulation thus trapping the water in the insulation, the leak can remain undetected for a long period. When the leak is finally discovered, the insulation has to be discharged...

  18. The pilot and demonstration SOLRIF project (Solar Roof Integration Frame); P+D Projekt SOLRIF (Solar Roof Integration Frame)

    Energy Technology Data Exchange (ETDEWEB)

    Ruoss, D.

    2000-07-01

    Building integration technologies for photovoltaic systems are, beside cell and module improvements, one of the most important aspects to reduce the price of solar electricity. But beside costs, there are other relevant requirements such as the architectural and aesthetical appearance of the building itself. SOLRIF is a new photovoltaic (PV) system for inclined roofs, which meets the aspects described above. Combined with any solar panel, SOLRIF forms a sealed roofing layer, like standard roofs with tiles, while generating electricity at the same time and offering a sustainable solution without greenhouse gases at zero operating costs. This new system is suitable for almost any type of inclined roofs in existing or new buildings and meets high aesthetical demands too. The innovative design is optimised in view of economical, ecological and functional aspects. The SOLRIF system consists of any type of PV laminate and four especially designed aluminium profiles, which replace the conventional framing of standard PV laminates. SOLRIF is independent of the size and makes of the PV laminates and is therefore suited to different products. During the two years project time 6 installations with a total amount of over 100 kW nominal power have been realised in Switzerland. Further approximately 150 kWp have been installed in Germany since the beginning of 2000. In advance, two test installations, one in Switzerland and one in the Netherlands were built. Several tests were done with the test installations in order to gain experiences at different locations. Improvements were done concerning the side finishing and on the profiles to reduce the material. The experiences with the installation and operation of SOLRIF elements are very positive. The product has reached a high quality level and has proved its proper function. (author)

  19. Flexible roof drill for low coal. Volume 2. Phase III and Phase IV

    Energy Technology Data Exchange (ETDEWEB)

    Shoup, N.H.

    1977-09-01

    Design specifications were developed for a flexible drilling and bolting system. The system configuration is based on the use of the Galis dual-boom roof drill as a vehicle for the drilling/bolting system. The WSU Flex-drill drivehead is mounted on the Galis drill boom and the Galis parts are modified to accommodate the revised system. The flexible drillhead supports a bolt bender/inserter designed by Bendix Corporation and is integrated into the system operation. A supplemental bolt thruster was designed to complete insertion of the roof bolt following operation and removal of the Bendix bender from the bolt shank. The complete cycle of drilling a 1-3/8-in. diameter bolt hole, bending a roof bolt into the hole, thrusting the bolt head and washer to the roof surface, and final torquing of the bolt is manually controlled by the operator located in the new position behind the bolting line. The new operating position is beneath newly bolted roof in a safer location in back of the stab jack ad roof jacks positioning the drill boom and drivehead. The Flex-drill/bolting system prototype was constructed from both purchased components and parts specially fabricated in the shops for this design. This unit was assembled and test-operated with appropriate support equipment in a laboratory test stand. Numerous test holes were drilled in blocks of concrete at feed rates of 5 ft/min with drill rotation speeds of 360 rpm. The drill feeds uniformly and cuts smoothly with no difficulty in collection of dust or clogging of the drill bit. The holes drilled were straight, as evidence by passage of a 1-1/4-in. diameter bar full depth into the hole with no binding or evidence of curvature. The flexible drill is capable of drilling 8-ft-deep roof bolt holes in low coal 36 in. in height.

  20. Effects of substrate properties on the hydraulic and thermal behavior of a green roof

    Science.gov (United States)

    Sandoval, V. P.; Suarez, F. I.; Victorero, F.; Bonilla, C.; Gironas, J. A.; Vera, S.; Bustamante, W.; Rojas, V.; Pasten, P.

    2014-12-01

    Green roofs are a sustainable urban development solution that incorporates a growing media (also known as substrate) and vegetation into infrastructures to reach additional benefits such as the reduction of: rooftop runoff peak flows, roof surface temperatures, energy utilized for cooling/heating buildings, and the heat island effect. The substrate is a key component of the green roof that allows achieving these benefits. It is an artificial soil that has an improved behavior compared to natural soils, facilitating vegetation growth, water storage and typically with smaller densities to reduce the loads over the structures. Therefore, it is important to study the effects of substrate properties on green roof performance. The objective of this study is to investigate the physical properties of four substrates designed to improve the behavior of a green roof, and to study their impact on the efficiency of a green roof. The substrates that were investigated are: organic soil; crushed bricks; a mixture of mineral soil with perlite; and a mixture of crushed bricks and organic soil. The thermal properties (thermal conductivity, volumetric heat capacity and thermal diffusivity) were measured using a dual needle probe (Decagon Devices, Inc.) at different saturation levels, and the hydraulic properties were measured with a constant head permeameter (hydraulic conductivity) and a pressure plate extractor (water retention curve). This characterization, combined with numerical models, allows understanding the effect of these properties on the hydraulic and thermal behavior of a green roof. Results show that substrates composed by crushed bricks improve the thermal insulation of infrastructures and at the same time, retain more water in their pores. Simulation results also show that the hydraulic and thermal behavior of a green roof strongly depends on the moisture content prior to a rainstorm.

  1. 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.

  2. Personal computer program and spreadsheet for calculating the coal mine roof rating (CMRR). Information circular/1994

    Energy Technology Data Exchange (ETDEWEB)

    Riefenberg, J.; Wuest, W.J.

    1994-01-01

    A family of personal computer programs that calculate the Coal Mine Roof Rating (CMRR) have been developed by the U.S. Bureau of Mines. The CMRR, rock mass classification system, was recently developed by Bureau researchers to provide a link between the qualitative geologists' description of coal mine roof and the quantitive mine engineers' needs for mine design, roof support selection, and hazard detection. The program CMRR, is a user-friendly, interactive program into which raw field data are input, and a CMRR is calculated and output along with two graphic displays. The first graphic display is a plan view map with the roof ratings displayed on a color-coded scale, and the second display shows a stratigraphic section of the bolted roof interval and its resultant roof rating. In addition, a Lotus 1-2-3 worksheet, BOM-CMRR.WK3, has been developed for easy storage of field data. The worksheet also includes macros developed for calculation and storage of the CMRR. Production of summary reports for analysis of site-specific information are readily generated using Lotus. These programs help to facilitate the engineer in utilizing the CMRR in ground control studies.

  3. 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.

  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. Nutrient subsidies to belowground microbes impact aboveground food web interactions.

    Science.gov (United States)

    Hines, Jes; Megonigal, J Patrick; Denno, Robert F

    2006-06-01

    Historically, terrestrial food web theory has been compartmentalized into interactions among aboveground or belowground communities. In this study we took a more synthetic approach to understanding food web interactions by simultaneously examining four trophic levels and investigating how nutrient (nitrogen and carbon) and detrital subsidies impact the ability of the belowground microbial community to alter the abundance of aboveground arthropods (herbivores and predators) associated with the intertidal cord grass Spartina alterniflora. We manipulated carbon, nitrogen, and detrital resources in a field experiment and measured decomposition rate, soil nitrogen pools, plant biomass and quality, herbivore density, and arthropod predator abundance. Because carbon subsidies impact plant growth only indirectly (microbial pathways), whereas nitrogen additions both directly (plant uptake) and indirectly (microbial pathways) impact plant primary productivity, we were able to assess the effect of both belowground soil microbes and nutrient availability on aboveground herbivores and their predators. Herbivore density in the field was suppressed by carbon supplements. Carbon addition altered soil microbial dynamics (net potential ammonification, litter decomposition rate, DON [dissolved organic N] concentration), which limited inorganic soil nitrogen availability and reduced plant size as well as predator abundance. Nitrogen addition enhanced herbivore density by increasing plant size and quality directly by increasing inorganic soil nitrogen pools, and indirectly by enhancing microbial nitrification. Detritus adversely affected aboveground herbivores mainly by promoting predator aggregation. To date, the effects of carbon and nitrogen subsidies on salt marshes have been examined as isolated effects on either the aboveground or the belowground community. Our results emphasize the importance of directly addressing the soil microbial community as a factor that influences

  6. Study of water infiltration in a lightweight green roof substrate

    Science.gov (United States)

    Tomankova, Klara; Holeckova, Martina; Jelinkova, Vladimira; Snehota, Michal

    2015-04-01

    Green roofs have a positive impact on the environment (e.g. improving microclimate and air quality in cities, reducing solar absorbance and storm water). A laboratory infiltration experiment was conducted on the narrow flume serving as 2D vertical model of a green roof. The lightweight Optigreen substrate Type M was used (depth of 20 cm). The front wall of the flume was transparent and inspected by digital camera. The experiment was designed to measure pressure head, volumetric water content and calculate water retention in the substrate. Experiment comprised three artificial rainfall intensities with different values of initial water content of the substrate. The experimental results confirmed that green roofs have the ability to retain rainwater and thus have a beneficial effect on reducing runoff. In the experiment with the artificial 10 minutes rainfall event (total precipitation of 29 mm), the air dry substrate retained 95.9 % of precipitation. On the other hand for moist initial condition 4.2 % of precipitations amount was captured in the substrate. Additionally, the analysis of images taken during the experiment confirmed preferential flow and uneven advancement of the wetting front. 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 Science Foundation under project number 14-10455P.

  7. Preservation of a traditional timber roof: the case of the Handanija mosque

    Directory of Open Access Journals (Sweden)

    Mevludin Zečević

    2012-01-01

    Full Text Available In this article, the authors provide a brief overview of their personal involvement in the inspection of the roof timbers of the Handanija Mosque in Prusac. As well as the inspection, the authors were asked to propose a design for the roof structure. The Handanija Mosque, built in 1617, is an important example of the cultural heritage of Bosnia and Herzegovina, the mosque was designated as a National Monument of Bosnia and Herzegovina in 2005. The form, design and proportions of this traditional vernacular building render it a unique example of the classical style.The mosque is rectangular in plan, with sides of 16.30 x 12.70 m, and belongs to the single-space type of mosque with an open porch and stone minaret. It was damaged by shelling during the 1992-1995 war, taking several direct hits to the walls, roof and minaret. The roof timbers were completely destroyed and the rest of the building was badly damaged.The authors suggested amending the structural bearing system by eliminating the hanging trusses and introducing the traditional components of posts, beams, struts and tie beams, as typical of this type of building. A 52.5° roof pitch was suggested, in keeping with Bosnia"s traditional vernacular architecture, which also reduces the intensity of horizontal forces. Authors suggest a 52.5° roof pitch for the following reasons: it is in keeping with the indigenous architecture of Central Bosnia, it reduces the intensity of horizontal forces, and it takes account of the fact that a hand-cut roof cladding does not always ensure identical geometry and pitch.

  8. ROOFER Inventory Procedures and Inspection Manual for Metal Panel Roofing

    Science.gov (United States)

    2012-12-01

    DESIGN CATEGORY CODE : I I I I I I TYPE CONST • : p I FACILITY NUMBER : I I I I I I I LOCATION : USE : I YEAR BUILT: ROOF SECTIONS : A 1,097 SF...INST . NO.: I I I I I I DATE : I I AGENCY I I NST .: BUILDING NAME : BUILDING NUMBER : DESIGN ~-TEGORY CODE : I I I I I I TYPE CONST...oov.nstope Sioo lfM H o oruns8810d I ....... , or ocner Integrated S!¥oght S!Ons or de<trooouon PanetOefect SPH jOint botwoen_ skylight panol and

  9. 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.

  10. Performance Evaluation and Field Application of Red Clay Green Roof Vegetation Blocks for Ecological Restoration Projects

    Directory of Open Access Journals (Sweden)

    Hwang-Hee Kim

    2017-02-01

    Full Text Available In this study, for restoration of ecological systems in buildings, porous vegetation red clay green roof blocks were designed for performance evaluation. Blast furnace slag (BFS; fine aggregates (agg., coarse aggregates, polyvinyl alcohol (PVA fiber (hydrophilic fiber, and red clay (ecofriendly additive material were applied to the construction of the porous vegetation red clay green roof blocks. A decrease in cement use is one way of reducing carbon emissions. To increase the water retentivity and the efficiency of roof vegetation blocks, blast furnace slag aggregates with excellent water absorptivity and polyvinyl alcohol fiber with a water absorption rate above 20% were added. In particular, the addition of polyvinyl alcohol fiber prevents performance reduction of the green roof vegetation blocks during freezing and melting in winter. Compressive strength, void ratio, and unit-mass tests were conducted to evaluate the performance of the roof vegetation blocks. After their application to roof vegetation, the effect of water purification was evaluated. According to the experimental results, the mix that satisfies the target performance of green roof vegetation blocks (compression strength above 8 MPa, void ratio above 20%, unit mass 2.0 kg/cm3 or below is: cement = 128.95 kg/m3, BFS = 96.75 kg/m3, red clay = 96.75 kg/m3, water = 81.50 kg/m3, BFS agg. = 1450 kg/m3, PVA fiber = 1.26 kg/m3. The green roof vegetation blocks were designed using the mix that satisfied the target performance. To find the amount of attainable water due to rainfall, a rainfall meter was installed after application of the roof vegetation to measure daily rainfall and calculate the amount of attainable water. The results show that, for 1 mm of rainfall, it is possible to attain about 0.53 L of water per 1 m2. In addition, the water quality of effluents after application of roof vegetation was analyzed, and the results satisfied Class 4 of the River-life Environmental

  11. Reconstruction of St. Petersburg roofs based on light steel thin-walled structures and de-icing system

    Directory of Open Access Journals (Sweden)

    N.I. Vatin

    2010-03-01

    Full Text Available Insecurity of applied coatings and low service lives of St. Petersburg roofs generate the development of new technological solutions. Necessity of roof protection from the ice dams is a special factor in selecting technological solutions of the roof structure.The aim is selection of an optimal design solution for the roof and the device against the ice based on the parameters of efficiency and effectiveness. After completion of research as a design of the roof system was chosen light steel thin-walled structures (LSTC. As the device against the ice is proposed a constructive adaptation of drainage, which includes the transfer of the gutter from the roof edge closer to Snow barriers. Herewith downspouts must finish in the system and urban runoff.Efficiency of this method is confirmed by mathematical calculations and trial operation of such existing systems in the Nordic countries. The combination of the device against the ice with modern technology LSTC solve the problem of icicles, and generally can guarantee continuous and reliable operation of the roof.

  12. 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.

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

    Science.gov (United States)

    Blue, Jarrod D; Souza, Lara; Classen, Aimée T; Schweitzer, Jennifer A; Sanders, Nathan J

    2011-11-01

    Nutrient availability and herbivory can regulate primary production in ecosystems, but little is known about how, or whether, they may interact with one another. Here, we investigate how nitrogen availability and insect herbivory interact to alter aboveground and belowground plant community biomass 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. Overall, we found a significant effect of reduced soil N availability on aboveground biomass and belowground plant biomass production. Specifically, responses of aboveground and belowground community biomass to nutrients were driven by reductions in soil N, but not additions, indicating that soil N may 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 manipulations and insect removals suggest strong bottom-up influences on total plant community productivity but more subtle effects of insect herbivores on aspects of aboveground and belowground production.

  14. 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.

  15. 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.

  16. Retention capacity of extensive green roofs

    Directory of Open Access Journals (Sweden)

    Sobczyk Małgorzata

    2016-09-01

    Full Text Available Climate change causes a more frequent occurrence of extreme events. The result of these phenomena is the occurrence of floods and flooding, and periods of drought. Particularly unfavorable is intensive rainfall over the urban catchments. To prevent the negative consequences of these phenomena, unconventional solutions should be used. The use of green roofs in urban areas will serve the sustainable development of cities and the impact on local ecological changes. The study was performed at two green roof platforms 1.2×1.2×0.1 m each. An analysis was performed at different intensities given for precipitation. 20 min for the rain to stop was observed from 68 to 100% precipitation. The study was divided into two parts. The first part of the study has been performed in the dry period. In contrast, another round of tests was repeated in other conditions after rainfall. The amount of water at two experimental green roofs platforms before the test was 11.0 dm3. The research relates to the impact of green roofs on local hydrological changes. Development of technologies for green roofs had a positive impact on mitigating the effects of climate change associated with the occurrence of flooding the city.

  17. Integrated real-time roof monitoring

    Institute of Scientific and Technical Information of China (English)

    SHEN Bao-tang; GUO Hua; KING Andrew

    2009-01-01

    CSIRO has recently developed a real-time roof monitoring system for under-ground coal mines and successfully tried the system in gate roads at Ulan Mine. The sys-tem integrated displacement monitoring, stress monitoring and seismic monitoring in one package. It included GEL multianchor extensometers, vibrating wire uniaxial stress meters, ESG seismic monitoring system with microseismic sensors and high-frequency AE sen-sors. The monitoring system automated and the data can be automatically collected by a central computer located in an underground nonhazardous area. The data are then trans-ferred to the surface via an optical fiber cable. The real-time data were accessed at any location with an Internet connection. The trials of the system in two tailgates at Ulan Mine demonstrate that the system is effective for monitoring the behavior and stability of read-ways during Iongwall mining. The continuous roof displacement/stress data show clear precursors of roof falls. The seismic data (event count and locations) provide insights into the roof failure process during roof fall.

  18. Fuel Consumption Impacts of Auto Roof Racks

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yuche; Meier, Alan

    2016-05-01

    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.

  19. Mapping Aboveground Biomass in the Amazon Basin: Exploring Sensors, Scales, and Strategies for Optimal Data Linkage

    Science.gov (United States)

    Walker, W. S.; Baccini, A.

    2013-05-01

    Information on the distribution and density of carbon in tropical forests is critical to decision-making on a host of globally significant issues ranging from climate stabilization and biodiversity conservation to poverty reduction and human health. Encouraged by recent progress at both the international and jurisdictional levels on the design of incentive-based policy mechanisms to compensate tropical nations for maintaining their forests intact, governments throughout the tropics are moving with urgency to implement robust national and sub-national forest monitoring systems for operationally tracking and reporting on changes in forest cover and associated carbon stocks. Monitoring systems will be required to produce results that are accurate, consistent, complete, transparent, and comparable at sub-national to pantropical scales, and satellite-based remote sensing supported by field observations is widely-accepted as the most objective and cost-effective solution. The effectiveness of any system for large-area forest monitoring will necessarily depend on the capacity of current and near-future Earth observation satellites to provide information that meets the requirements of developing monitoring protocols. However, important questions remain regarding the role that spatially explicit maps of aboveground biomass and carbon can play in IPCC-compliant forest monitoring systems, with the majority of these questions stemming from doubts about the inherit sensitivity of satellite data to aboveground forest biomass, confusion about the relationship between accuracy and resolution, and a general lack of guidance on optimal strategies for linking field reference and remote sensing data sources. Here we demonstrate the ability of a state-of-the-art satellite radar sensor, the Japanese ALOS/PALSAR, and a venerable optical platform, Landsat 5, to support large-area mapping of aboveground tropical woody biomass across a 153,000-km2 region in the southwestern Amazon

  20. Rams Head Center : an innovative vegetative roof plaza at the University of North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Adams, M.; Potts, A. [Cahill Associates Inc., West Chester, PA (United States)

    2006-07-01

    A newly constructed vegetative roof plaza on the University of North Carolina Chapel Hill campus serves as a link between 2 sides of the campus. The multi-use Rams Head Center is a green roof plaza constructed over a large parking garage. As part of the campus's expansion plans, the University set rigorous environmental goals, such as balancing growth with preservation of natural drainage systems; managing stormwater as an opportunity instead of a problem; managing total stormwater volume on-site; enhancing and protecting the water quality of streams; and, reinforcing the University as a role model. During large storms, the entire green roof system discharges into a bioswale, a stormwater infiltration bed, and a recreated stream segment. The 40,000 square foot green roof plaza includes a 56,000 gallon cistern and a permanent water storage zone under the planting soil to support trees and shrubs. Visual stormwater connections and signs are placed to raise community awareness of water resource issues. This paper reviewed the basic design principles for the remainder of non-cistern areas of the green roof. Issues regarding landscape design, seasonal operation and maintenance were also discussed. 7 refs., 14 figs.

  1. Roofing as a source of nonpoint water pollution.

    Science.gov (United States)

    Chang, Mingteh; McBroom, Matthew W; Scott Beasley, R

    2004-12-01

    Sixteen wooden structures with two roofs each were installed to study runoff quality for four commonly used roofing materials (wood shingle, composition shingle, painted aluminum, and galvanized iron) at Nacogdoches, Texas. Each roof, either facing NW or SE, was 1.22 m wide x 3.66 m long with a 25.8% roof slope. Thus, there were 32 alternatively arranged roofs, consisting of four roof types x two aspects x four replicates, in the study. Runoff from the roofs was collected through galvanized gutters, downspouts, and splitters. The roof runoff was compared to rainwater collected by a wet/dry acid rain collector for the concentrations of eight water quality variables, i.e. Cu(2+), Mn(2+), Pb(2+), Zn(2+), Mg(2+), Al(3+), EC and pH. Based on 31 storms collected between October 1997 and December 1998, the results showed: (1) concentrations of pH, Cu, and Zn in rainwater already exceed the EPA freshwater quality standards even without pollutant inputs from roofs, (2) Zn and Cu, the two most serious pollutants in roof runoff, exceeded the EPA national freshwater water quality standards in virtually 100% and more than 60% of the samples, respectively, (3) pH, EC, and Zn were the only three variables significantly affected by roofing materials, (4) differences in Zn concentrations were significant among all roof types and between all roof runoff and rainwater samples, (5) although there were no differences in Cu concentrations among all roof types and between roof runoff and rainwater, all means and medians of runoff and rainwater exceeded the national water quality standards, (6) water quality from wood shingles was the worst among the roof types studied, and (7) although SE is the most frequent and NW the least frequent direction for incoming storms, only EC, Mg, Mn, and Zn in wood shingle runoff from the SE were significantly higher than those from the NW; the two aspects affected no other elements in runoff from the other three roof types. Also, Zn concentrations from

  2. 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

  3. Aboveground burial for managing catastrophic losses of livestock

    Directory of Open Access Journals (Sweden)

    Gary Alan Flory

    2017-09-01

    Full Text Available Background and Aim: Environmental impacts from carcass management are a significant concern globally. Despite a history of costly, ineffective, and environmentally damaging carcass disposal efforts, large animal carcass disposal methods have advanced little in the past decade. An outbreak today will likely be managed with the same carcass disposal techniques used in the previous decades and will likely result in the same economic, health, and environmental impacts. This article overviews the results of one field test that was completed in Virginia (United States using the aboveground burial (AGB technique and the disposal of 111 foot-and-mouth disease (FMD infected sheep in Tunisia using a similar methodology. Materials and Methods: Researchers in the United States conducted a field test to assess the environmental impact and effectiveness of AGB in decomposing livestock carcasses. The system design included a shallow trench excavated into native soil and a carbonaceous base placed on the bottom of the trenches followed by a single layer of animal carcasses. Excavated soils were subsequently placed on top of the animals, and a vegetative layer was established. A similar methodology was used in Tunisia to manage sheep infected with FMDs, Peste des Petits Ruminants virus, and Bluetongue Virus. Results: The results of the field test in the United States demonstrated a significant carcass degradation during the 1-year period of the project, and the migration of nutrients below the carcasses appears to be limited thereby minimizing the threat of groundwater contamination. The methodology proved practical for the disposal of infected sheep carcasses in Tunisia. Conclusions: Based on the analysis conducted to date, AGB appears to offer many benefits over traditional burial for catastrophic mortality management. Ongoing research will help to identify limitations of the method and determine where its application during large disease outbreaks or natural

  4. 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

  5. Flat roof integration. CPT solar (AET IV)

    Energy Technology Data Exchange (ETDEWEB)

    Chianese, D.; Pola, I.; Bernasconi, A.; Bura, E.; Cereghetti, N.; Realini, A.; Pasinelli, P.; Rioggi, S.

    2007-11-15

    This illustrated final report for the Swiss Federal Office of Energy (SFOE) takes a look at a 15.4 kWp solar power installation in Trevano, Switzerland, that features flexible amorphous silicon triple-junction modules, mounted nearly horizontally and directly laminated to flexible polyolefin membranes that form the covering of a flat roof. The main objective of this study was to verify in which order of magnitude the better thermal behaviour of amorphous silicon cells can compensate for losses due to the quasi-horizontal roof integration (lower irradiation and higher reflection), and thus be competitive in the flat roof construction and refurbishment markets. The modules used and their characteristics are described. Performance, temperature levels and energy-production are reviewed for the panels of the installation. The performance of the inverter used is also reviewed. Data on temperatures and production are presented in graphical form and optical losses are examined.

  6. 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.

  7. 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.

  8. Weak roof fall simulation for a longwall face

    Energy Technology Data Exchange (ETDEWEB)

    Nazimko, V.V.; Khalimendick, U.M.; Zborshtchick, M.P.; Danilov, V.K.; Sugakov, V.A. [Donetsk State Technical University, Donetsk (Ukraine)

    1999-07-01

    A particle flow algorithm has been employed to investigate immediate roof stability. It is demonstrated that weak rock layers and a lack of powered supports are the most important factors which impact stability to the roof. 1 ref., 4 figs.

  9. Thermoplastic Single-Ply Roof Relieves Water Damage and Inconvenience.

    Science.gov (United States)

    Williams, Jennifer Lynn

    2002-01-01

    Assesses use of thermoplastic single-ply roofs by North Carolina's Mars Hill College to prevent leaks, reduce maintenance costs, and enhance the value of their older historic buildings. Administrators comment on the roof's installation efficiency and cleanliness. (GR)

  10. Stability analysis of subgrade cave roofs in karst region

    Institute of Scientific and Technical Information of China (English)

    蒋冲; 赵明华; 曹文贵

    2008-01-01

    According to the engineering features of subgrade cave roof in karst region, the clamped beam model of subgrade cave roof in karst region was set up. Based on the catastrophe theory, the cusp catastrophe model for bearing capacity of subgrade cave roof and safe thickness of subgrade cave roof in karst region was established. The necessary instability conditions of subgrade cave roof were deduced, and then the methods to determine safe thickness of cave roofs under piles and bearing capacity of subgrade cave roof were proposed. At the same time, a practical engineering project was applied to verifying this method, which has been proved successfu1ly. At last, the major factors that affect the stability on cave roof under pile in karst region were deeply discussed and some results in quality were acquired.

  11. Interactions between aboveground and belowground induced responses against phytophages

    NARCIS (Netherlands)

    Dam, van N.M.; Harvey, J.A.; Waeckers, F.L.; Bezemer, T.M.; Putten, van der W.H.; Vet, L.E.M.

    2003-01-01

    Since their discovery about thirty years ago, induced plant responses have mainly been studied in interactions of plants with aboveground (AG) pathogens, herbivores and their natural enemies. Many induced responses, however, are known to be systemic and thus it is likely that responses induced by AG

  12. Family Differences Influence the Aboveground Biomass of Loblolly Pine Plantations

    Science.gov (United States)

    P.E. Pope; D.L. Graney

    1979-01-01

    We compared the aboveground biomass of 4 half-sib families of loblolly pine (Pinus taeda L.) 11 years after planting. Total dry weights differed significantly among families in plantations on the same soil type with the same site index. Differences in biomass resulted from differences in stem form and branch size. Distribution of growth -the proportion of tree weight...

  13. 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

    A growing body of evidence shows that aboveground and belowground communities and processes are intrinsically linked, and that feedbacks between these subsystems have important implications for community structure and ecosystem functioning. Almost all studies on this topic have been carried out f...

  14. 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...

  15. Forecasting annual aboveground net primary production in the intermountain west

    Science.gov (United States)

    For many land manager’s annual aboveground net primary production, or plant growth, is a key factor affecting business success, profitability and each land manager's ability to successfully meet land management objectives. The strategy often utilized for forecasting plant growth is to assume every y...

  16. Inventory of Tank Farm equipment stored or abandoned aboveground

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-10-12

    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.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    The stocks of iron (Fe), manganese (Mn), zinc (Zn) and aluminium (Al) in different compartments of the aboveground tree biomass were estimated in Scots pine (Pinus sylvestris L.) stands in Lithuania. Simulated removals of metals due to the forest biomass extraction in a model Scots pine stands...

  18. 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

  19. Roof separation characteristics of laminated weak roof strata of longwall roadway

    Institute of Scientific and Technical Information of China (English)

    LU Ting-kan; LIU Yu-zhou

    2004-01-01

    The roof separation was investigated in a coal mine as part of the site characterization of roof strata deterioration in a longwall roadway. The separation of laminated,weak roof strata was initially characterized as the maximum separation, effect of geological setting on separation and the effect of mining activities (heading development,time-dependent and longwall extraction) on separation. Then the separation process was studied, so as to answer the questions of: when the separation occurs; where the separation is located and what geological setting it relates to; how large of the separation is; and how the separation propagates.

  20. The Benefits of Green Roofing for Latvian Building Environment

    OpenAIRE

    Kara, P.; Pastars, P

    2013-01-01

    Green roofs serve several purposes for a building, such as absorbing rainwater, providing insulation, creating a habitat for wildlife and helping to lower urban air temperatures and mitigate the heat island effect. The modern trend started when green roofs were developed in Germany in the 1960s, and has since spread to many countries. Today, it is estimated that about 10% of all German roofs have been “greened”. Green roofs are also becoming increasingly popular in the United States, although...

  1. The Self-Drying Concept for Flat Roofs

    DEFF Research Database (Denmark)

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

    1996-01-01

    Moisture in flat roof systems with an insulation layer has been a long-standing issue for the roof industry. It is now realised, that it is unrealistic and too costly to try to completely keep moisture from entering a roof assembly during its service life. The approach, therefore, should be to ke...... 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....

  2. [Aboveground architecture and biomass distribution of Quercus variabilis].

    Science.gov (United States)

    Yu, Bi-yun; Zhang, Wen-hui; Hu, Xiao-jing; Shen, Jia-peng; Zhen, Xue-yuan; Yang, Xiao-zhou

    2015-08-01

    The aboveground architecture, biomass and its allocation, and the relationship between architecture and biomass of Quercus variabilis of different diameter classes in Shangluo, south slope of Qinling Mountains were researched. The results showed that differences existed in the aboveground architecture and biomass allocation of Q. variabilis of different diameter classes. With the increase of diameter class, tree height, DBH, and crown width increased gradually. The average decline rate of each diameter class increased firstly then decreased. Q. variabilis overall bifurcation ratio and stepwise bifurcation ratio increased then declined. The specific leaf areas of Q. variabilis of all different diameter classes at vertical direction were 0.02-0.03, and the larger values of leaf mass ratio, LAI and leaf area ratio at vertical direction in diameter level I , II, III appeared in the middle and upper trunk, while in diameter level IV, V, VI, they appeared in the central trunk, with the increase of diameter class, there appeared two peaks in vertical direction, which located in the lower and upper trunk. The trunk biomass accounted for 71.8%-88.4% of Q. variabilis aboveground biomass, while the branch biomass accounted for 5.8%-19.6%, and the leaf biomass accounted for 4.2%-8.6%. With the increase of diameter class, stem biomass proportion of Q. variabilis decreased firstly then increased, while the branch and leaf biomass proportion showed a trend that increased at first then decreased, and then increased again. The aboveground biomass of Q. variabilis was significantly positively correlated to tree height, DBH, crown width and stepwise bifurcation ratio (R2:1), and positively related to the overall bifurcation ratio and stepwise bifurcation ratio (R3:2), but there was no significant correlation. Trunk biomass and total biomass aboveground were negatively related to the trunk decline rate, while branch biomass and leaf biomass were positively related to trunk decline

  3. Assessing aboveground tropical forest biomass using Google Earth canopy images.

    Science.gov (United States)

    Ploton, Pierre; Pélissier, Raphaël; Proisy, Christophe; Flavenot, Théo; Barbier, Nicolas; Rai, S N; Couteron, Pierre

    2012-04-01

    Reducing Emissions from Deforestation and Forest Degradation (REDD) in efforts to combat climate change requires participating countries to periodically assess their forest resources on a national scale. Such a process is particularly challenging in the tropics because of technical difficulties related to large aboveground forest biomass stocks, restricted availability of affordable, appropriate remote-sensing images, and a lack of accurate forest inventory data. In this paper, we apply the Fourier-based FOTO method of canopy texture analysis to Google Earth's very-high-resolution images of the wet evergreen forests in the Western Ghats of India in order to (1) assess the predictive power of the method on aboveground biomass of tropical forests, (2) test the merits of free Google Earth images relative to their native commercial IKONOS counterparts and (3) highlight further research needs for affordable, accurate regional aboveground biomass estimations. We used the FOTO method to ordinate Fourier spectra of 1436 square canopy images (125 x 125 m) with respect to a canopy grain texture gradient (i.e., a combination of size distribution and spatial pattern of tree crowns), benchmarked against virtual canopy scenes simulated from a set of known forest structure parameters and a 3-D light interception model. We then used 15 1-ha ground plots to demonstrate that both texture gradients provided by Google Earth and IKONOS images strongly correlated with field-observed stand structure parameters such as the density of large trees, total basal area, and aboveground biomass estimated from a regional allometric model. Our results highlight the great potential of the FOTO method applied to Google Earth data for biomass retrieval because the texture-biomass relationship is only subject to 15% relative error, on average, and does not show obvious saturation trends at large biomass values. We also provide the first reliable map of tropical forest aboveground biomass predicted

  4. Study of Falling Roof Vibrations in a Production Face at Roof Support Resistance in the Form of Concentrated Force

    Science.gov (United States)

    Buyalich, G. D.; Buyalich, K. G.; Umrikhina, V. Yu

    2016-08-01

    One of the main reasons of roof support failures in production faces is mismatch of their parameters and parameters of dynamic impact on the metal structure from the falling roof during its secondary convergences. To assess the parameters of vibrational interaction of roof support with the roof, it was suggested to use computational models of forces application and a partial differential equation of fourth order describing this process, its numerical solution allowed to assess frequency, amplitude and speed of roof strata movement depending on physical and mechanical properties of the roof strata as well as on load bearing and geometry parameters of the roof support. To simplify solving of the differential equation, roof support response was taken as the concentrated force.

  5. 40 CFR 63.1042 - Standards-Separator fixed roof.

    Science.gov (United States)

    2010-07-01

    ...) National Emission Standards for Oil-Water Separators and Organic-Water Separators § 63.1042 Standards... controlling air emissions from an oil-water separator or organic-water separator using a fixed roof. (b) The... interface of the roof edge and the separator wall. (3) Each opening in the fixed roof shall be equipped...

  6. Recovery and reuse of asphalt roofing waste. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Desai, S.; Graziano, G.; Shepherd, P.

    1984-02-02

    Burning of asphalt roofing waste as a fuel and incorporating asphalt roofing waste in bituminous paving were identified as the two outstanding resource recovery concepts out of ten studied. Four additional concepts might be worth considering under different market or technical circumstances. Another four concepts were rated as worth no further consideration at this time. This study of the recovery of the resource represented in asphalt roofing waste has identified the sources and quantities of roofing waste. About six million cubic yards of scrap roofing are generated annually in the United States, about 94% from removal of old roofing at the job site and the remainder from roofing material production at factories. Waste disposal is a growing problem for manufacturers and contractors. Nearly all roofing waste is hauled to landfills at a considerable expense to roofing contractors and manufacturers. Recovery of the roofing waste resource should require only a modest economic incentive. The asphalt contained in roofing waste represents an energy resource of more than 7 x 10/sup 13/ Btu/year. Another 1 x 10/sup 13/ Btu/year may be contained in field-applied asphalt on commercial building roofs. The two concepts recommended by this study appear to offer the broadest applicability, the most favorable economics, and the highest potential for near-term implementation to reuse this resource.

  7. Green Roof Technology- Mitigate Urban Heat Island (UHI Effect

    Directory of Open Access Journals (Sweden)

    Odli Z.S. M.

    2016-01-01

    Full Text Available Alterations on the land surfaces, which are attributed by human activities, especially in cities, cause many implications to the ecosystem. The increase of buildings in cities is reflecting the growth of human activities resulted in a significant temperature increase and warmer pattern in the urban area than the surrounding countryside. The phenomenon defined as urban heat island. This study investigates the application and efficiency of the green roof as an approach to mitigate urban heat island and reducing indoor temperature in a building. Two types of roof models, which consist of vegetative roof and non-vegetative roof, were built to investigate the efficiency of vegetated roof in reducing indoor temperature compared to the non-vegetated roof. The outdoor and indoor temperature and humidity of each roof model were monitored by using RH520 Thermo Hygrometer. The data was collected for three times in a week for 9 weeks at 9:00am to 5:00pm. It was found that the indoor average temperature data for vegetative roof could be reduced 2.4°C from the outdoor average temperature and 0.8°C for non-vegetative roof. The difference of temperature reduction for vegetative roof was greater than the nonvegetative roof, thus indicate that green roof was highly efficient in reducing indoor temperature and mitigate urban heat island impact.

  8. Green roof establishment in extreme conditions : two case studies

    Energy Technology Data Exchange (ETDEWEB)

    Grothe, R. [Aloha Landscaping, Inc., Mendota Heights, MN (United States); Trichie, J. [Shakopee Mdewakanton Sioux Community, MN (United States)

    2007-07-01

    Green roof construction in the United States is growing at a rate of 60 to 80 per cent per year. This paper presented two case studies of green roof construction in Minnesota. In both cases, construction and budgeting delays moved the installation of the green roofs from early-May to mid-July. The first case study was a 20,000 square foot extensive green roof on the new Minneapolis Central Library which was completed in 2005. The second case study was a 30,000 square foot extensive green roof on the Mdewakanton Sioux Waste Water Treatment Plant in Shakopee, which was completed in 2006. This paper demonstrated that in order for green roofs to serve the functions for which they were intended, clear guidelines and specifications are needed to ensure that they are healthy. The size and locations of the two roofs were quite different, but they were identical in terms of waterproofing. State-of-the-art inverted hot-applied roof membrane technology was used in both roofs along with sub-surface irrigation systems. A mycorrhizae fungi was used in both cases to amend the growing medium. Both roofs used a diverse pallet of native and traditional sedum plant material. This paper highlighted preventative measures taken to ensure the successful installation and establishment of the two roofs built during extreme heat and drought-like conditions. The positive results confirm that it is possible to install green roofs during extremely harsh summer conditions. 9 refs., 4 tabs., 3 figs.

  9. 30 CFR 75.211 - Roof testing and scaling.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Roof testing and scaling. 75.211 Section 75.211 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Roof Support § 75.211 Roof testing and scaling. (a)...

  10. Causes of falls of roof in South African collieries

    CSIR Research Space (South Africa)

    Van der Merwe, JN

    2001-08-01

    Full Text Available on ta l s tre ss W ea th er ing Ba d m ini ng Dy ke s Bu rn t c oa l Contribution (% ) All Skin Large Major Figure 25. Causes of roof falls seen against the background of thickness of roof falls. 24 10 Influence of roof rock...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-08-01

    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.

  12. 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.

  13. Detailed Design of the Roof Steel Sheets in Hainan International Convention and Exhibition Center%海南国际会展中心屋盖蒙皮钢板深化设计

    Institute of Scientific and Technical Information of China (English)

    高继领

    2012-01-01

    The roof structure of Hainan International Convention and Exhibition Center consists of a single layer shell, a three-layer grid and trapezoidal trusses. Steel sheets with three different thicknesses were used. The middle part of the roof took the shape of alternate concave and convex surfaces, and surrounding the middle part was irregular waving surfaces. According to the surface characteristics of the steel sheets, both spatial software of Rhinoceros and AutoCAD were used and perfect interaction was achieved between them to achieve an accurate and efficient lofting of expansion of the surfaces. Divisions were also made to approximate the irregular curved surfaces into a combination of rugby-styled surfaces and inclined circular cone surfaces, which simplified the construction process.%海南国际会展中心屋盖结构形式为单层网壳、3层网架和梯形桁架组成的结构体系,整个屋面采用3种厚度钢板.屋面中间部分由相间排布的凹凸曲面组成,周边区域为不规则波浪形曲面.根据钢结构屋盖蒙皮钢板的曲面特点,利用空间造型软件Rhinoceros与AutoCAD,使两种软件无缝对接,从而高效、高精度地实现空间曲面的放样展开;并通过对蒙皮钢板的合理分块,使任意曲面简化为近似橄榄球曲面及近似斜圆锥台曲面,简化了曲面加工难度.

  14. 40 CFR 65.45 - External floating roof converted into an internal floating roof.

    Science.gov (United States)

    2010-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Storage Vessels § 65.45... control storage vessel regulated material emissions by using an external floating roof converted into an...

  15. Assessment of a fiber-optic distributed-temperature-sensing system to monitor the thermal dynamics of vegetated roof

    Science.gov (United States)

    Cousiño, J. A.; Hausner, M. B.; Victorero, F.; Bonilla, C.; Gironas, J. A.; Vera, S.; Bustamante, W.; Rojas, V.; Pasten, P.; Suarez, F. I.

    2014-12-01

    Vegetated (green) roofs include a growing media and vegetation layer, and offer a range of benefits such as the reduction of: the heat island effect, rooftop runoff peak flows, roof surface temperatures, energy used for cooling or heating buildings, and noise levels inside infrastructures. Vegetated roofs also offer aesthetic benefits and increase the biodiversity of the urban environment, and are increasingly used in sustainable urban development. Understanding the thermal dynamics of vegetated roofs will make it possible to improve their design and to better assess their impacts on energy efficiency. Here, we evaluate the first vertical high-resolution distributed-temperature-sensing (DTS) system installed in a vegetated roof. This system allows a continuous measurement of the thermal profile within a vegetated roof - going from the interior, upward through the drainage layers and soil substrate of the vegetated roof and ending in the air above the vegetation. Temperatures can be observed as frequently as every 30 s at a spatial resolution on the order of centimeters. This DTS system was installed in the "Laboratory of Vegetal Infrastructure of Buildings" (LIVE - its acronym in Spanish), located in the San Joaquín Campus of the Pontifical Catholic University, Santiago, Chile. The laboratory features 18 experimental modules to investigate different configurations of the vegetated roof layers. The LIVE was designed with the installation of the optical fibers in mind, and the DTS system allows simultaneous monitoring of three or four modules of the LIVE. In this work, we describe the design of this DTS deployment, the calibration metrics obtained using the software provided by the manufacturers, and other calibration algorithms previously developed. We compare the results obtained using single- and double-ended measurements, highlighting strengths and weaknesses of DTS methods. Finally, we present the observations obtained from this biophysical environment

  16. Assessment of the potential of roof turbine ventilators for bathroom ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Ishiow Kuo [National United Univ., Dept. of Architecture, Miao-li City (Taiwan); Chiming Lai [Leader Univ., Dept. of Construction Technology, Tainan City (Taiwan)

    2005-06-15

    This study set out to investigate the potential of installing a new common roof turbine ventilator on to an existing bathroom ventilation system which serves 14 bathrooms in the first dormitory block of Leader University in Taiwan, and evaluate the overall ventilation performance of this new combination. Field measurements of airflow in the ventilation ducts and low-speed wind tunnel experiments for this turbine ventilator were carried out. The results showed that the combination of the roof turbine ventilator and bathroom ventilation were successful in achieving sufficient air change rate in bathrooms, and this ventilation design alternative is now proposed as a method of improving the indoor air environment in bathrooms. (Author)

  17. 30 CFR 75.204 - Roof bolting.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Roof bolting. 75.204 Section 75.204 Mineral... or the equivalent may be used. (3) Bearing plates used with wood or metal materials shall be at least... against wood; or (ii) Have exceeded the maximum specified torque or tension by 50 percent. (6) The...

  18. One Roof Judicial System in Indonesia

    Directory of Open Access Journals (Sweden)

    - Sufiarina

    2012-09-01

    Full Text Available Judicial power as an independent and autonomous power must be free from any intervention and power, thus ensuring that judges possess independence and impartiality in handling cases. One of the measures for enhancing the independence and autonomy of the judiciary is by placing it under the one roof judicial arrangement developed by the Supreme Court, both from the judicial as well as the non-judicial technical aspects. Up to the present time, endeavors for bringing the four court jurisdictions under the one roof judicial arrangement developed by the Supreme Court have not been completely materialized, due to the existing dualism in judicial power at various courts. The objective of this research is to understand the developments in the endeavors towards bringing the Indonesian judicial system under the one roof judicial arrangement developed by the Supreme Court. The type of research applied is descriptive normative juridical research, namely legal research based on examining secondary data. As the research results indicate, the one roof system developed by the Supreme Court is already being implemented, with the exception of the Military Court and the Tax Court within the State Administration Court jurisdiction.

  19. 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...

  20. Roof-Top rainwater harvesting system for official / multistoried building with reference to malda district, WB

    Directory of Open Access Journals (Sweden)

    Dr. Suman

    2017-01-01

    Full Text Available Rain water harvesting is received increased attention world wide as an alternative source of water. Roof-top rain water harvesting system is looked upon as one of the most feasible and economical ways of water conservation. With increasing problem of water scarcity, planning and designing roof top rain water harvesting is gaining wider importance to meet ever-increasing water demand, encouraging use of water or more sustainable basis. The rain water harvesting is the simple collection or storing of water for the domestic or the agriculture purpose. The method of rain water harvesting has been into practice since ancient times. The method is simple and cost effective too. Malda district of West Bengal is badly affected by Arsenic contamination in ground water. The present study finds its usefulness in developing awareness towards judicious use of water among masses and efficient ways to harvest roof top rain water resources at institutional / multistoried buildings in Malda district.

  1. 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 < 0.05), and the first-flush effect did not occur during the 27 simulated rain events. The results also revealed that the concentration of these nutrient pollutants in the runoff strongly depended on the features of the nutrient substrates used in the 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.

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

    Science.gov (United States)

    Ceulemans, Tobias; Hulsmans, Eva; Berwaers, Sigi; Van Acker, Kasper; Honnay, Olivier

    2017-01-01

    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. PMID:28333985

  3. In situ estimation of roof rock strength using sonic logging

    Energy Technology Data Exchange (ETDEWEB)

    Oyler, David C.; Mark, Christopher; Molinda, Gregory M. [NIOSH-Pittsburgh Research Laboratory, Pittsburgh, PA (United States)

    2010-09-01

    Sonic travel time logging of exploration boreholes is routinely used in Australia to obtain estimates of coal mine roof rock strength. Because sonic velocity logs are relatively inexpensive and easy to obtain during exploration, the technique has provided Australian underground coal mines with an abundance of rock strength data for use in all aspects of ground control design. However, the technique depends upon reliable correlations between the uniaxial compressive strength (UCS) and the sonic velocity. This paper describes research recently conducted by NIOSH aimed at developing a correlation for use by the U.S. mining industry. From two coreholes in Illinois, two from Pennsylvania, and one each from Colorado, western Kentucky and southern West Virginia, sonic velocity logs were compared with UCS values derived from Point Load tests for a broad range of coal measure rock types. For the entire data set, the relationship between UCS and sonic travel time is expressed by an exponential equation relating the UCS in psi to the travel time of the P-wave in {mu}s/ft. The coefficient of determination or R-squared for this equation is 0.72, indicating that a relatively high reliability can be achieved with this technique. The strength estimates obtained from the correlation equation may be used to help design roof support systems. The paper also addresses the steps that are necessary to ensure that high-quality sonic logs are obtained for use in estimating UCS. (author)

  4. Status of cool roof standards in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hashem; Levinson, Ronnen

    2007-06-01

    Since 1999, several widely used building energy efficiency standards, including ASHRAE 90.1, ASHRAE 90.2, the International Energy Conservation Code, and California's Title 24 have adopted cool roof credits or requirements. We review the technical development of cool roof provisions in the ASHRAE 90.1, ASHRAE 90.2, and California Title 24 standards, and discuss the treatment of cool roofs in other standards and energy-efficiency programs. The techniques used to develop the ASHRAE and Title 24 cool roof provisions can be used as models to address cool roofs in building energy standards worldwide.

  5. 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

  6. Green roofs as a means of pollution abatement.

    Science.gov (United States)

    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.

  7. 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

  8. 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

  9. Green Roof Evaluation: A Holistic ‘Long Life, Loose Fit, Low Energy’ Approach

    Directory of Open Access Journals (Sweden)

    Craig Langston

    2015-11-01

    Full Text Available Green roofs have potential to improve the social and environmental performance of detached housing in Australia, yet often they are overlooked due to prohibitive capital cost and a range of other perceptions that are difficult to quantify. A classic evaluation problem is invoked that must balance short and long term benefits. Using two distinct designs of the same floor area, green roof and traditional housing prototypes are analysed to determine the relative ‘breakeven’ point when long-term benefits become feasible. It is discovered that green roofs are unlikely to be viable in their own right, but when coupled with an overall design strategy of long life (durability, loose fit (adaptability and low energy (sustainability they can deliver least cost (affordability over time as well as unlock valuable social and environmental rewards. This outcome can be realised within 25% of a home’s expected design life of at least one hundred years. The results demonstrate that residential green roofs, when integrated as part of a holistic approach, can be both individually and collectively justified on key economic, social and environmental criteria, and are therefore able to claim a valuable contribution towards wider sustainable development goals.

  10. Impact of climate and vegetation type on evapotranspiration from green roofs

    Science.gov (United States)

    Sia, M. E.; Robinson, C. E.; O'Carroll, D. M.; Voogt, J. A.; Smart, C. C.; Way, D. A.

    2015-12-01

    Green roofs are an increasingly popular low impact development tool used to mitigate the adverse effects of urbanization and the loss of vegetated spaces. The benefits of green roofs include reducing stormwater volume and peak flows, reducing building energy loads, and mitigating the urban heat island effect. Evapotranspiration (ET) is a key process fundamental to hydrologic and thermal performance of green roofs. For example, ET governs the water storage volume available in the soil medium and thus the ability of the green roof to retain and attenuate stormwater. Green roof design considerations such as soil medium depth and plant type impact ET rates. Additionally, climate has a strong impact on ET rates. To date, the influence between climate and green roof design factors (e.g. vegetation type and soil medium depth) on ET rates have not been well quantified. We performed a field study to evaluate the impact of climate, vegetation type, and soil medium depth on ET rates from extensive modular green roofs over prolonged drying periods. Three Canadian cities with distinct climates were chosen as field sites: London, ON, Calgary, AB, and Halifax, NS. At each site, daily module weights were recorded from May to August in 2013 and 2014 for approximately 40 green roof modules. These modules were divided into four vegetation treatments (three single species and one mixed species), and each treatment was divided into two groups of soil medium depth (10 cm or 15 cm). Daily ET rates and seasonal moisture loss were calculated and compared for the modules to determine which treatment provided the highest ET rates. The root depth profile, leaf area index, and stomatal resistance were also measured. On average, daily ET rates among the vegetation treatments did not vary greatly, however, observations on plant survival indicate which plant types are best suited for each site. In all three sites, mixed species in 15 cm of soil medium had higher seasonal moisture loss compared to

  11. 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

  12. MODELING OF THE SNOW LOAD ON THE ROOFS OF INDUSTRIAL BUILDINGS

    Directory of Open Access Journals (Sweden)

    Zolina Tat’yana Vladimirovna

    2016-08-01

    Full Text Available When designing load-bearing framework structures using the method of limiting states it is necessary to determine the maximum possible value of snow load for the entire period of operation of an industrial building for the possibility of transition. The magnitude of the snow load is randomly changed over the time, and therefore the most appropriate form of its display is a probabilistic model of random process. The authors have identified the most preferable approach to modeling of snow load. It consists in presenting a selective sequence of the year maximums in the form of a continuous random variable distributed according to the Gumbel law. Its parameters are expressed through the mathematical expectation and the standard sample set of meteorological observations. According to the calculated values of the parameters the authors have built a graphic interpretation of the law of distribution of this random variable. When building a model of the total snow load on the roof of a building the influence of various factors should be considered, such as: • snow shedding at a given roof slope; • snow movement caused by wind; • distribution of snow depending on the roof shape; • snow melting depending on the thermal characteristics of the roof; • the ability to drain meltwater from the surface of the roof. The resulting model of snow load is adapted for implementation using software complex “DINCIB-new” developed by the authors. The proposed approach to the modeling of the snow load on the roof of an industrial building allows correlating the repeatability period of its limit calculated value with the residual life of the research object. This has become possible due to the multiple implementation of an automated algorithm for calculating an industrial building, which was developed by the authors, with account of the varying values of snow load in relation to the corresponding mathematical expectation, with registering the quantities of

  13. Studies on Hydroponics Design and Its Effect of Vegetables on the Roof Platform of Buildings%楼顶平台蔬菜水培系统设计及应用效果

    Institute of Scientific and Technical Information of China (English)

    陶正平; 李梦玲; 边鸣镝

    2001-01-01

    By circulating hydroponic culture technique to soilless cultur e of vegetables on the roof platform of buildings, we could get higher ec onomic and social benefit.In south China,12~16 powing periods of green veg etables could be planted in a year,which produced by an average of 52~66 kilogr ams or 58 yuan per square meter.The key cultural techniques is how to make u se of win dbreak wall、shelter shed and other equipments,as well as how to overcome greatl y variable microclimate conditions on the top of buildings.%在平顶楼房的顶部平台,利用循环水培技术进行蔬菜无土栽培,具有较高的 经济效益和社会效益,在南方地区,每年可生产绿叶蔬菜12~16茬,平均每平方米可生产蔬 菜52~66kg,每平方米面积创利58元。其栽培关键技术是利用防风墙、防护棚等设施,克服 楼房顶部小气候条件变化激烈问题。

  14. 坡屋顶的绿化技术%THE TECHNICAL MEASURES OF GREENING OF SLOPING ROOF

    Institute of Scientific and Technical Information of China (English)

    李海英; 杨洁

    2014-01-01

    The present study of roof greening is more concentrated in the flat roof , and less in the sloping roof .With respect to flat roof , loss of soil and water is the main problem of greening of sloping roofs .The paper studied anti-skid measures, irrigation and drainage system and combining with rainwater collection to popularize the design of greening of sloping roofs .%目前屋顶绿化的研究大多集中于平屋顶,而坡屋顶的较少;相对平屋顶,水土流失是坡屋顶绿化存在的主要问题。通过研究坡屋顶绿化的防滑措施、灌溉方式、蓄排水系统及结合雨水收集等关键技术来推广和普及坡屋顶绿化的设计。

  15. Improving the durability of flat roof constructions

    DEFF Research Database (Denmark)

    Rudbeck, Claus Christian; Svendsen, Sv Aa Højgaard

    1999-01-01

    Flat roof constructions are mainly used on commercial, institutional and industrial buildings, where insulation is placed on top of the load-bearing deck and then covered with a roof membrane. Through time, there is a risk that the membrane will allow water passage as holes might form due...... to weathering effects or physical loads. Water will then enter the insulation, and as a vapor retarder is normally found below the insulation thus trapping the water in the insulation, the leak can remain undetected for a long period. When the leak is finally discovered, the insulation has to be discharged...... 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...

  16. PERFORMANCE OF AN EARTHQUAKE EXCITED ROOF DIAPHRAGM.

    Science.gov (United States)

    Celebi, M.; Brady, G.; Safak, E.; Converse, A.; ,

    1986-01-01

    The objective of this paper is to study the earthquake performance of the roof diaphragm of the West Valley College gymnasium in Saratoga, California through a complete set of acceleration records obtained during the 24 April 1984 Morgan Hill Earthquake (M equals 6. 1). The roof diaphragm of the 112 ft. multiplied by 144 ft. rectangular, symmetric gymnasium consists of 3/8 in. plywood over tongue-and-groove sheathing attached to steel trusses supported by reinforced concrete columns and walls. Three sensors placed in the direction of each of the axes of the diaphragm facilitate the evaluation of in-plane deformation of the diaphragm. Other sensors placed at ground level measure vertical and horizontal motion of the building floor, and consequently allow the calculation of the relative motion of the diaphragm with respect to the ground level.

  17. Lightning Protection of Floating Roof Tanks

    Directory of Open Access Journals (Sweden)

    Adekitan,

    2013-10-01

    Full Text Available Prior to export, processed crude oil is stored in Floating Roof Tanks (FRT to further allow any trapped gas within the crude oil to escape, as this stabilises the crude oil. In the oil and gas industry, FRT’s are vital in the processing of crude oil to the acceptable export specification.In the tropics and other lightning prone regions, lightning induced floating roof tank fire constitutes a major threat to crude oil production. Among others, a single lightning incident could result in the loss of life, product and production time, avoidable incident review time, damaged equipment, wasted repair cost, bad publicity and loss of income.This paper therefore, is aimed at providing an effective solution to the menace of lightning induced tank fire by focussing on the starting process of the lightning induced fire and proposing alternative concepts for breaking the fire triangle before fire ensues

  18. 南水北调工程七里河倒虹吸管身顶板台车的设计与施工%Design and construction of roof formwork trolley for Qilihe Inverted Siphon of South-to-North Water Transfer Project

    Institute of Scientific and Technical Information of China (English)

    王永兴; 李茜

    2012-01-01

    根据南水北调工程邢台七里河渠道倒虹吸工程管身的结构特点、施工质量和工程进度,设计了管身顶板台车,详细介绍了其结构特点、功能原理及施工工艺.而且对其非标关键部件主梁进行了强度和刚度计算,应用有限元方法,分析了轨道管的强度和安全性.此外,通过与传统组合钢模板和隧道模板台车施工工艺的对比分析,得出结论:采用管身顶板台车模板具有良好的施工质量和综合效益.%According to the structure characteristics, the construction quality and die work schedule of Qilihe Canal Inverted Siphon located in Xingtai City of the South-to-North Water Transfer Project, a roof formwork trolley for the construction of the inverted siphon is designed and the structural features, function principle and construction technology of the trolley are describedherein in detail. Furthermore, the calculation on the strength and stiffness of the main beam-a non-standardized key part ismade and the strength and safety of the steel pipe for railway is analyzed with the finite element method. Moreover, through a comparative analysis made with the conventional combined steel formwork and tunnel formwork trolley, a conclusion is obtained that better construction quality and comprehensive benefit can be got with the roof formwork trolley for construction of inverted siphon presented hereia

  19. 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.

  20. Experimental Polyurethane Foam Roof Systems - II.

    Science.gov (United States)

    1983-01-01

    reflect the effects of cloud cover, windspeed, and radiation from the roof during early morning and late evening hours. Measurement of the area under the...INN \\k I, N’. tlir’I’iii V A I \\’A SIurelS42r. K110i tlIe. I ct Ili Solair i imip .\\r nill. Kiw\\\\, tMe. I N I C(I’ 0)1,4 (IC, Ni’rtolk. \\.A ( ( I

  1. 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.

  2. EXTRUDED POLYSTYRENE FOAM IN FLAT ROOFS

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2014-09-01

    Full Text Available In our article we prove the necessity of applying thermal insulation with low water absorption and resistance and preserving mechanical and thermophysical properties in corrosive environment in flat roofs, where there is always a danger of penetrating condensed moisture into the structure. As such material we offered extruded polystyrene foam - heat-insulating polymer material with uniformly distributed closed cells. The products are used in the form of slab insulation and special items - for forming slopes and venting.

  3. Control of roofs difficult to break down

    Energy Technology Data Exchange (ETDEWEB)

    Lukashov, V.G.; Suslyakov, V.P.; Korobov, A.N.

    1981-03-01

    This paper describes a method of advanced torpedoing a roof difficult to break down at the Polysaevskaya coal mine. It consists in placing explosive charges in the roof ahead of the coal face. Three schemes were tested: boreholes were drilled parallel to the face, perpendicular or inclined at an angle to the face. Boreholes were 112 mm in diameter and their length ranged from 30 to 100 m, distance between the boreholes amounted to 20 m. 6ZhV ammonite explosive, 90 mm in diameter and 500 mm long, were used. Torpedos were 2 m long, and separated by 3 to 4 m long air pockets. When a roof characterized by a high compressive strength coefficient (about 10 on the Protod'yakonov scale) was torpedoed, 250 kg of ammonite were used for a borehole 80 m long, and 160 kg for a borehole 50 m long. When borehole length was reduced to 40 m explosive consumption decreased to 117 kg. In the case of rocks with compressive strength coefficient of 6, explosive amount was two times lower. In a coal mine in which an OKP-70 face system was used applying advanced torpedoing increased labor productivity of the face by 30% and reduced cost of mining by 42%. Number of work accidents was reduced 13 times. (In Russian)

  4. Roof pre-blasting to prevent support crushing and water inrush accidents

    Institute of Scientific and Technical Information of China (English)

    Wang Xiaozhen; Xu Jialin; Zhu Weibing; Li Yingchun

    2012-01-01

    Support crushing and water inrush when mining under an unconsolidated confined aquifer in the Qidong Coal Mine was prevented by roof pre-blasting.The mechanism and applicable conditions for this method have been studied.The results show that when an overburden structure that may cause support crushing and a water inrush accident exists the weakening of the primary key stratum,which thereby reduces its weighting step,roof pre-blasting is both feasible and effective.If the position of the primary key stratum can be moved upward to exceed 10 times the mining height the possibility of support crushing and water inrush disaster caused by key stratum compound breakage will be lowered.The overburden structure of the number 7121 working face was considered during the design of a technical proposal involving roof pre-blasting.After comprehensively analyzing the applicability of roof pre-blasting the resulting design prevented support crushing and water inrush disasters from happening at the number 7121 working face and laid a solid foundation for mining safely.

  5. 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.

  6. Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models

    NARCIS (Netherlands)

    Johnson, Michelle O.; Galbraith, David; Gloor, Manuel; Deurwaerder, De Hannes; Guimberteau, Matthieu; Rammig, Anja; Thonicke, Kirsten; Verbeeck, Hans; Randow, Von Celso; Monteagudo, Abel; Phillips, Oliver L.; Brienen, Roel J.W.; Feldpausch, Ted R.; Lopez Gonzalez, Gabriela; Fauset, Sophie; Quesada, Carlos A.; Christoffersen, Bradley; Ciais, Philippe; Sampaio, Gilvan; Kruijt, Bart; Meir, Patrick; Moorcroft, Paul; Zhang, Ke; Alvarez-Davila, Esteban; Alves De Oliveira, Atila; Amaral, Ieda; Andrade, Ana; Aragao, Luiz E.O.C.; Araujo-Murakami, Alejandro; Arets, Eric J.M.M.; Arroyo, Luzmila; Aymard, Gerardo A.; Baraloto, Christopher; Barroso, Jocely; Bonal, Damien; Boot, Rene; Camargo, Jose; Chave, Jerome; Cogollo, Alvaro; Cornejo Valverde, Fernando; Lola Da Costa, Antonio C.; Fiore, Di Anthony; Ferreira, Leandro; Higuchi, Niro; Honorio, Euridice N.; Killeen, Tim J.; Laurance, Susan G.; Laurance, William F.; Licona, Juan; Lovejoy, Thomas; Malhi, Yadvinder; Marimon, Bia; Marimon, Ben Hur; Matos, Darley C.L.; Mendoza, Casimiro; Neill, David A.; Pardo, Guido; Peña-Claros, Marielos; Pitman, Nigel C.A.; Poorter, Lourens; Prieto, Adriana; Ramirez-Angulo, Hirma; Roopsind, Anand; Rudas, Agustin; Salomao, Rafael P.; Silveira, Marcos; Stropp, Juliana; Steege, Ter Hans; Terborgh, John; Thomas, Raquel; Toledo, Marisol; Torres-Lezama, Armando; Heijden, van der Geertje M.F.; Vasquez, Rodolfo; Guimarães Vieira, Ima Cèlia; Vilanova, Emilio; Vos, Vincent A.; Baker, Timothy R.

    2016-01-01

    Understanding the processes that determine aboveground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody producti

  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...

  8. 公共游憩型屋顶花园设计解析*--以日本琦玉广场屋顶花园为例%Design Analysis of Recreational Public Green Roof--Case Study of Saitama Plaza in Japan

    Institute of Scientific and Technical Information of China (English)

    钱万惠; 唐洪辉; 赵庆

    2016-01-01

    公共游憩型屋顶花园利用建筑“第五立面”创造生态绿色空间,是城市公共空间发展的新方向。文章通过文献资料研究及实地调查,提出了公共游憩型屋顶花园基本设计原则,以日本琦玉广场屋顶花园为具体案例,对其设计方法、建造技术与材料运用进行分析,总结出公共游憩型屋顶花园的建设必须依赖科学合理的设计、恰当的选材及先进的建造技术,三者缺一不可。%Recreational public green roof, which use the fifth elevation of building to create ecological greenspace, is a new direction for the development of urban public space. After literature review and site to visit, this paper summarized the basic design principle and used Saitama Plaza in Japan as an case study to analyse it’s designing methods and the application of techniques and materials, aiming at providing reference to the future research and design.

  9. Can green roofs provide habitat for urban bees (Hymenoptera: Apidae?

    Directory of Open Access Journals (Sweden)

    Laurence Packer

    2009-01-01

    Full Text Available Increasing urbanization of many regions of the world has resulted in the decline of suitable habitat for wild flora and fauna. Green roofs have been suggested as a potential avenue to provide patches of good-quality habitat in highly developed regions. In this study, we surveyed green roofs for bee diversity and abundance to determine their potential as quality habitats in an urban area for these important pollinators. By comparing various biodiversity measures between green roofs and ground-level sites, we show that green roofs provide habitat to many bee species. Implications for pollinator conservation and urban agricultural production are discussed.

  10. Green roofs in Germany : yesterday, today and tomorrow

    Energy Technology Data Exchange (ETDEWEB)

    Herman, R. [Anhalt Univ., Bernburg (Germany)

    2003-07-01

    This presentation provided a historical overview of the development of green roofs in Germany. Real interest in green roof technology in Germany began in the 1970s at which time specific guidelines for correct installation were established. In the past 20 years there has been a dramatic increase in the number of green roofs. The main market drivers were ecological concerns, energy and cost saving potential, as well as the need to manage storm water. Green roofs have an insulating effect, leading to energy savings. Some cities in Germany have implemented an incentive program whereby reductions on city water fees are allocated to owners of green roofs. Many business opportunities have been created by an increased interest in green roofs. The demand for lava, pumice, expanded clay, recycled roof tiles, crushed brick and other materials is being met by a new industry. There has been a noted increase in green roof systems and components, as well as installation and maintenance companies. It is expected that the ever increasing price for land in German cities along with an increasing population density will spur an even greater demand for green roofs. Germany is considered one of the greenest countries in the world, due to public concern for all forms of pollution, the maintenance of ecological balance, the preservation of flora and fauna, and a respect for nature. 6 refs.

  11. STRUCTURE AND STABILITY OF MAIN ROOF AFTER ITS FRACTURE

    Institute of Scientific and Technical Information of China (English)

    朱德仁; 钱鸣高

    1990-01-01

    A serics of physical modelings in which a main roof is considered as a Kirchhoff plate supported or clammed by Winkler elastic foundation were performed to simulate the fracturing process of the main roof in longwall mining. Based on these modelings spatial structures of the main roof after its fracture are described, blocks of the fractured main roof are classified and their behaviors are analyzed in this paper. Additionally, two stability indexes of the structures are defined, and the factors affecting stability of the structures with different boundaries and geometric conditions are discussed.

  12. Human and environmental controls over aboveground carbon storage in Madagascar

    Directory of Open Access Journals (Sweden)

    Asner Gregory P

    2012-01-01

    Full Text Available Abstract Background Accurate, high-resolution mapping of aboveground carbon density (ACD, Mg C ha-1 could provide insight into human and environmental controls over ecosystem state and functioning, and could support conservation and climate policy development. However, mapping ACD has proven challenging, particularly in spatially complex regions harboring a mosaic of land use activities, or in remote montane areas that are difficult to access and poorly understood ecologically. Using a combination of field measurements, airborne Light Detection and Ranging (LiDAR and satellite data, we present the first large-scale, high-resolution estimates of aboveground carbon stocks in Madagascar. Results We found that elevation and the fraction of photosynthetic vegetation (PV cover, analyzed throughout forests of widely varying structure and condition, account for 27-67% of the spatial variation in ACD. This finding facilitated spatial extrapolation of LiDAR-based carbon estimates to a total of 2,372,680 ha using satellite data. Remote, humid sub-montane forests harbored the highest carbon densities, while ACD was suppressed in dry spiny forests and in montane humid ecosystems, as well as in most lowland areas with heightened human activity. Independent of human activity, aboveground carbon stocks were subject to strong physiographic controls expressed through variation in tropical forest canopy structure measured using airborne LiDAR. Conclusions High-resolution mapping of carbon stocks is possible in remote regions, with or without human activity, and thus carbon monitoring can be brought to highly endangered Malagasy forests as a climate-change mitigation and biological conservation strategy.

  13. [Aboveground biomass of three conifers in Qianyanzhou plantation].

    Science.gov (United States)

    Li, Xuanran; Liu, Qijing; Chen, Yongrui; Hu, Lile; Yang, Fengting

    2006-08-01

    In this paper, the regressive models of the aboveground biomass of Pinus elliottii, P. massoniana and Cunninghamia lanceolata in Qianyanzhou of subtropical China were established, and the regression analysis on the dry weight of leaf biomass and total biomass against branch diameter (d), branch length (L), d3 and d2L was conducted with linear, power and exponent functions. Power equation with single parameter (d) was proved to be better than the rests for P. massoniana and C. lanceolata, and linear equation with parameter (d3) was better for P. elliottii. The canopy biomass was derived by the regression equations for all branches. These equations were also used to fit the relationships of total tree biomass, branch biomass and foliage biomass with tree diameter at breast height (D), tree height (H), D3 and D2H, respectively. D2H was found to be the best parameter for estimating total biomass. For foliage-and branch biomass, both parameters and equation forms showed some differences among species. Correlations were highly significant (P biomass, with the highest for total biomass. By these equations, the aboveground biomass and its allocation were estimated, with the aboveground biomass of P. massoniana, P. elliottii, and C. lanceolata forests being 83.6, 72. 1 and 59 t x hm(-2), respectively, and more stem biomass than foliage-and branch biomass. According to the previous studies, the underground biomass of these three forests was estimated to be 10.44, 9.42 and 11.48 t x hm(-2), and the amount of fixed carbon was 47.94, 45.14 and 37.52 t x hm(-2), respectively.

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

    Science.gov (United States)

    Epstein, Scott A; Lee, Sang-Mi; Katzenstein, Aaron S; Carreras-Sospedra, Marc; Zhang, Xinqiu; Farina, Salvatore C; Vahmani, Pouya; Fine, Philip M; Ban-Weiss, George

    2017-08-22

    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 California's Title 24 building energy efficiency standards within the heavily populated and polluted South Coast Air Basin (SoCAB). Development of a comprehensive rooftop area database and evaluation of spectral reflectance measurements of roofing materials allows us to project potential future changes in solar and UV reflectance for simulations using the Weather Research Forecast and Community Multiscale Air Quality (CMAQ) models. 2012 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.

  15. Retrieval of Aboveground Biomass Using Multi-Frequency SAR

    Science.gov (United States)

    Stelmaszczuk-Gorska, Martyna; Thiel, Christian; Schmullius, Christiane

    2016-08-01

    The objective of this study was to investigate above-ground biomass (AGB) estimation in forests by combining multi-frequency Synthetic Aperture Radar (SAR) L-band and C-band data. An area of Siberian boreal forest was selected for this study. The results demonstrated that relatively high estimation accuracy can be obtained at the spatial resolution of 0.5 ha using the L- and C-band SAR backscatter. Overall, the AGB estimation error was calculated to be approximately 24 t ha-1 using the Random Forests machine learning algorithm.

  16. 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.

  17. 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

    and strike the liner, accelerating its degradation. The purpose of this study is to estimate the extent and duration of the exposure. A typical gap is modelled in a ray-tracing program and the size and position of the illuminated area on the liner is calculated for given directions of the light beam relative...... 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....... 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...

  18. 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.

  19. Implementing Sustainability Criteria for Selecting a Roof Assembly Typology in Medium Span Buildings

    Directory of Open Access Journals (Sweden)

    Julian Canto-Perello

    2015-05-01

    Full Text Available Technological advances have allowed the development of new roof assembly typologies with higher efficiency and less waste. However, in the construction sector the focus is generally on reducing cost and not in sustainable development factors. Short-sighted building planning based only on economic criteria should be avoided improving decision support systems. In addition, the selection of an appropriate roof assembly in a building’s design stage is a complex problem due to the existence of different tangible and intangible factors and the multiple alternatives available. The roof typologies under study involve prefabricated concrete, steel and laminated wood structures. This research work applies a multi-criteria hybrid model combining the Analytical Hierarchy Process with the Delphi method and the VIKOR technique for implementing sustainability criteria in the selection of a roof assembly in medium span buildings. The proposed decision support system enables the use of the triple bottom line that considers economic, social and environmental criteria. Under the criteria analyzed, the compromise solution found is the self-supporting curved system.

  20. 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.

  1. COMPARATIVE STUDY OF DIFFERENT TYPES OF ROOF AND INDOOR TEMPERATURES IN TROPICAL CLIMATE

    Directory of Open Access Journals (Sweden)

    Mrs. M. Ponni

    2015-04-01

    Full Text Available A roof provides protection to be safe from direct sunlight. From the shelter, shadow alone is not expected. Durability, sustainability, less life cycle cost, and low maintenance cost are expected from a selected roof. The world has a thirst to have a best roof. No roof will fulfil the requirement of humanity since the climatic conditions are different. Hence the roof should be selected according to the prevailing climate. And the roof selection depends on the need, taste and the spending capability of the house owner. Thatched shed, tiles covered roof, light roofs either using galvanized sheets or asbestos sheets, painted or unpainted metal sheets, RCC, Green roof, Roof pond, insulated roof, reflective roof, and cool roof are the roofs so far brought into use. Whatever be the roof, it should provide thermal comfort. Thermal comfort is felt through the thermal experience of the occupants. Thermal experience depends on the indoor temperature. Energy efficiency of a building is highly based on the indoor ambient temperature. Energy efficiency in buildings is compelling, cost effective, saves money and useful to compromise resource energy shortage. A light roof named as Single Decker (SID and an insulated double roof using hybrid technique named as (DOD are taken for this study. Among the selected roofs the DOD provides a better thermal performance and thermal comfort. The study has been carried out for the summer peak period in April 2014. Thermal performance and indoor temperature of the DOD is compared with other roof studies.

  2. Numerical study of rock bolting parameter variation effect on stability of stratified, composite roof structure of drift in a coal mine

    Institute of Scientific and Technical Information of China (English)

    LU Ting-kan; LIU Yu-zhou

    2005-01-01

    Described the outcomes of a comprehensive numerical modeling on the rock bolting performance for preventing the deformation of stratified, composite roof structure of drift in a coal mine. The investigation was undertaken in the adverse geological conditions, with variation of belt parameters, including length, density, distribution, pretension,as well as the geometry of opening, so as to determine the effect of bolting parameter variation on roof deformation and stability. The outcomes clearly demonstrated that a significant improvement of roof stability can be achieved associating with bolting parameters optimization, and indicated the importance of flexible geotechnical designation of rock mbolting reinforcement in mining practice.

  3. [Effect of flooding disturbance on aboveground biomass of Leymus chinensis grassland--a preliminary study].

    Science.gov (United States)

    Wang, Zhengwen; Zhu, Tingcheng

    2003-12-01

    To investigate the effect of flooding disturbance on the net primary productivity of Songnen steppe, a comparatively thorough study was conducted on Sanjiadian State-owned Rangeland in Da'an city, Jilin Province, which was partly flooded in 1998. The study site was located in the south Songnen plain of Northeastern China, dominated by Leymus chinensis grassland. An extensively mild slope with flooding gradients (from un-flooded to heavily flooded) was taken as the study site. Two flooded transects coded FL and FH which was respectively subjected to 3 and 9 months of flooding were designed, and an un-flooded one coded CK at a relatively higher elevation was set as a control. Before flooding occurred in 1998, the slope had an almost uniform soil and L. chinensis dominated vegetation. Each transect was 0.2 hm2 (100 m x 20 m) in size, and the two flooded transects were almost paralleled each other, with the longer sides of them perpendicular to the retrieving direction of floodwater. In each transect twenty 1 m2 sized quadrats were randomly chosen to survey the community structure and the aboveground biomass. Comparative analyses were made on the dynamics of soil water, soil N and P, and species composition of grassland communities that occurred in responses to flooding disturbance. The results showed that the lightly and heavily flooded transects had a significantly larger aboveground biomass than the control, with the increase of 89.54% and 113.45%, respectively. The heavily flooded transect had a slightly but insignificantly larger aboveground biomass than the lightly flooded one, indicating that on flooded sites, water was not the limiting factor of the aboveground biomass. The acute changes of soil water caused by flooding led to the changes of soil nutrients and species assemblages, which would impact community biomass. Just as the case for aboveground biomass, the soil water contents of the two flooded transects were significantly larger than that of control

  4. Linkages between below and aboveground communities: Decomposer responses to simulated tree species loss are largely additive.

    Science.gov (United States)

    Becky A. Ball; Mark A. Bradford; Dave C. Coleman; Mark D. Hunter

    2009-01-01

    Inputs of aboveground plant litter influence the abundance and activities of belowground decomposer biota. Litter-mixing studies have examined whether the diversity and heterogeneity of litter inputs...

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

    OpenAIRE

    Mees, Heleen

    2014-01-01

    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 green roof, thereby helping to promote the general acceptance of green roofs in the city. However, the researcher thinks this policy should be followed up: “You can’t award grants forever.”

  6. Estimating Heat and Mass Transfer Processes in Green Roof Systems: Current Modeling Capabilities and Limitations (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Tabares Velasco, P. C.

    2011-04-01

    This presentation discusses estimating heat and mass transfer processes in green roof systems: current modeling capabilities and limitations. Green roofs are 'specialized roofing systems that support vegetation growth on rooftops.'

  7. 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

  8. 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

  9. 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......-sections with low strength and stiffness will generally not have large load effects. Further, there can be system effects due to non-linear material behavior. In this paper a stochastic model is established for the bending strength and stiffness of timber beams. Next, stochastic models for typical timber structural...

  10. The Geometric Theory of Roof Reflector Resonators

    Science.gov (United States)

    1976-12-01

    with solid state lasers, beginning in 1967. Soncini and Svelto (Refs 39 and 40) and Cubeddu, Polloni, Sacchi, and Svelto (Ref 11) have used pairs of 900...used by these authors is shown in Fig. 5. 13 In all experiments the output was found to be highly repeatable from pulse to pulse. Soncini and Svelto ...DeLang and Boumhuis (Fig. 4(b) ) and Soncini and Svelto (Fig. 5 ) have observed in their lasers are the samn except that iii the former the roof

  11. Carbon Sequestration Potential of Extensive Green Roofs%屋顶绿地碳固定潜力的研究

    Institute of Scientific and Technical Information of China (English)

    陈爱葵; 陆剑; 袁剑刚; 徐亚幸; 杨中艺

    2015-01-01

    .Mean decrease of CO2 concentration and CO2 exchange rate in the chamber over the measurement period were 77.8 ×10 -6 and -0.24 g·m -2·h -1 ,respectively.However,there was a high degree of variability because the photosynthesis rate of green roof plant greatly is dependent on light intensity and temperature,which change from time to time.Decrease of CO2 concentrations ranged from 23.50 ×10 -6 to 162.00 ×10 -6 ,and CO2 exchange rates ranged from -0.06 to -0.46 g·m -2·h -1 in the chamber.In the aboveground harvest experiment,data of the carbon reserve investigations showed that these green roofs stored an average of 92.55 g·m -2 in aboveground biomass with also a wide variability (from 39.47 to 138.41 g·m -2 ),depended on the harvested biomass and carbon content of the biomass collected from the studied green roofs.In addition,it is notable that a significant correlation (R2 =0.93) was observed between plant carbon content and substrate depth,while the correlations between substrate nutrient variables and carbon content was not statistically significant.Overall,the experimental results suggested that green roof can reduce the CO2 concentration in surrounding environment by absorbing CO2 in the daytime and act as a small carbon sink in urban area.It is likely that substrate depth may have big impacts on green roof carbon sequestration potential.Additional sophisticated research should be needed to evaluate the factors that contribute to the carbon sequestration potential of green roofs.

  12. Atmospheric contribution to boron enrichment in aboveground wheat tissues.

    Science.gov (United States)

    Wang, Cheng; Ji, Junfeng; Chen, Mindong; Zhong, Cong; Yang, Zhongfang; Browne, Patrick

    2017-05-01

    Boron is an essential trace element for all organisms and has both beneficial and harmful biological functions. A particular amount of boron is discharged into the environment every year because of industrial activities; however, the effects of environmental boron emissions on boron accumulation in cereals has not yet been estimated. The present study characterized the accumulation of boron in wheat under different ecological conditions in the Yangtze River Delta (YRD) area. This study aimed to estimate the effects of atmospheric boron that is associated with industrial activities on boron accumulation in wheat. The results showed that the concentrations of boron in aboveground wheat tissues from the highly industrialized region were significantly higher than those from the agriculture-dominated region, even though there was no significant difference in boron content in soils. Using the model based on the translocation coefficients of boron in the soil-wheat system, we estimated that the contribution of atmosphere to boron accumulation in wheat straw in the highly industrialized region exceeded that in the agriculture-dominated region by 36%. In addition, from the environmental implication of the model, it was estimated that the development of boron-utilizing industries had elevated the concentration of boron in aboveground wheat tissues by 28-53%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. 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.

  14. 郑州市屋顶绿化现状及分析%The Roof Greening Situation and Analysis of Zhengzhou

    Institute of Scientific and Technical Information of China (English)

    张秋红

    2014-01-01

    屋顶绿化在城市绿化美化中占有重要作用,拥有巨大的市场潜力。通过对郑州市现有及施工中屋顶花园的调查勘测,从屋顶绿化的设计和工程两大部分进行研究分析,并对比两种屋顶绿化的建造形式(简单式屋顶绿化和花园式屋顶绿化)。总结郑州市屋顶绿化规划中存在的问题与不足,并针对这些问题和不足提出改进措施和规划意见。%Roof greening plays an important role in urban greening landscaping, and has huge market potential. Based on the investigation of roof garden existing and under construction in Zhengzhou, two parts that contained the design and engineering of roof greening were analyzed. And the two roof greening construction forms (simple roof greening and garden green roof) were compared. This paper summarized the existing problems about roof greening planning of Zhengzhou, and put forward some superficial improvement measures and planning ideas to solve these problems and deficiencies.

  15. BioTRIZ Suggests Radiative Cooling of Buildings Can Be Done Passively by Changing the Structure of Roof Insulation to Let Longwave Infrared Pass

    Institute of Scientific and Technical Information of China (English)

    Salmaan Craig; David Harrison; Andrew Cripps; Daniel Knott

    2008-01-01

    This paper demonstrates the application of a design tool called Bio TRIZ. Its developers claim that it can be used to access biological strategies for solving engineering problems. Our aim is to design a roof for hot climates that gets free cooling through radiant coupling with the sky. The insulation in a standard roof stops the sun and convection from warming the thermal mass.But it also restricts the mass's longwave view of the cool sky. Different solutions to this conflict are offered by BioTRIZ. The chosen solution is to replace the standard insulation component with an open cell honeycomb. The vertical cells would allow longwave radiation to pass, while arresting convection. The solutions offered by BioTRIZ's technological counterpart include no such changes in structure. It is estimated that the thermal mass in the biomimetic roof would remain on average 4.5℃ cooler than in a standard roof over a year in Riyadh, Saudi Arabia.

  16. Discussion on technical measures for water saving of roof greening%屋顶绿化节水技术措施的探讨

    Institute of Scientific and Technical Information of China (English)

    杨晓宇

    2014-01-01

    Combined with the specific characteristics of roof greening , hydrophobic layer of water -saving irrigation technology of roof greening and planting area of roof garden structural layer is improved , the reasonable design thoughts solving the roof greening irrigation and drainage problems often meet in the course of designing were put forward .%本文结合屋顶绿化的具体特点,探讨屋顶绿化的节水灌溉技术的选择和屋顶花园种植区构造层中的疏水层改进,对解决屋顶绿化灌溉与排水设计过程中常遇见的问题提出了合理的设计思路。

  17. 深圳天麓三区种植屋面施工技术%Shenzhen Tianlu 3rd Zone planted roof construction technology

    Institute of Scientific and Technical Information of China (English)

    石伟国

    2011-01-01

    In Shenzhen Tianlu 3rd Zone Rhine Castle project, basement roof is designed as the sky garden, and it is planted roof above the waterproof layer. This paper introduces the waterproof design scheme, waterproof material characteristics, roof greening, and construction process of the planted roof.%深圳天麓三区莱茵堡项目地下室顶板设计为空中花园,防水层上为种植屋面.介绍该种植屋面防水设计方案、防水材料特点、屋面绿化及种植屋面的施工工艺.

  18. 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

  19. DIFFERENT ROOF BEHAVIOUR UNDER DIFFERENT UPPER MINING BOUNDARY CONDITION IN DATONG

    Institute of Scientific and Technical Information of China (English)

    康立勋

    1997-01-01

    Understanding roof behaviour and immediate roof failure patterns of Iongwall face is a prerequisite for establishing correct roof control theory and appplying effective roof control measures. Roof behaviour and immediate roof failure pattern have a close relationship with upper mining boundary conditions of Iongwall face. According to actual situation of Datong Mining Area, upper mining boundary conditions of Iongwall face have been classified into 5 types in this paper. Roof behaviour and immediate roof failure pattern under each upper mining boundary condition are discussed in details.

  20. 40 CFR 63.1043 - Standards-Separator floating roof.

    Science.gov (United States)

    2010-07-01

    ...) National Emission Standards for Oil-Water Separators and Organic-Water Separators § 63.1043 Standards... controlling air emissions from an oil-water separator or organic-water separator using a floating roof. (b... floating roof shall be equipped with two continuous seals, one above the other, between the wall of...

  1. 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.

  2. Hydrologic Restoration in the Urban Environment Using Green Roofs

    Directory of Open Access Journals (Sweden)

    Anna Palla

    2010-04-01

    Full Text Available Loss of natural soil and vegetation within the urban environment can significantly affect the hydrologic cycle by increasing storm water runoff rates and volumes. In order to mitigate these modifications in urban areas engineered systems are developed, such as green roofs, to mimic and replace functions (evapo-transpiration, infiltration, percolation which have been altered due to the impact of human development. Green roofs, also known as vegetated roof covers, eco-roofs or nature roofs, are composite complex layered structures with specific environmental benefits. They are increasingly being used as a source control measure for urban storm water management. Indeed, they are able to re-establish the natural water cycle processes and to operate hydrologic control over storm water runoff with a derived peak flow attenuation, runoff volume reduction and increase of the time of concentration. Furthermore green roofs exhibit the capacity to reduce storm water pollution; they generally act as a storage device, consequently pollutants are accumulated in the substrate layer and released when intensive rainwater washes them out. In order to investigate the hydrologic response of a green roof, the University of Genova recently developed a joint laboratory and full-scale monitoring programme by installing a “controlled” laboratory test-bed with known rainfall input and a companion green roof experimental site (40 cm depth in the town of Genoa. In the paper, data collected during the monitoring programme are presented and compared with literature data.

  3. Requirements of inverted roofs with a drainage layer

    DEFF Research Database (Denmark)

    Leimer, Hans-Peter; Rode, Carsten; Künzel, Hartwig

    2005-01-01

    This contribution illustrates the application of the standard EN ISO 6946 regarding the heat loss of an inverted roof for different regions of Europe. An addendum to the standard (EN ISO 6946:1996/A1, 2003) introduces a correction to the thermal transmittance of inverted roofs due to rain water f...

  4. Hygrothermal Performance of West Coast Wood Deck Roofing System

    Energy Technology Data Exchange (ETDEWEB)

    Pallin, Simon B [ORNL; Kehrer, Manfred [ORNL; Desjarlais, Andre Omer [ORNL

    2014-02-01

    Simulations of roofing assemblies are necessary in order to understand and adequately predict actual the hygrothermal performance. At the request of GAF, simulations have been setup to verify the difference in performance between white and black roofing membrane colors in relation to critical moisture accumulation for traditional low slope wood deck roofing systems typically deployed in various western U.S. Climate Zones. The performance of these roof assemblies has been simulated in the hygrothermal calculation tool of WUFI, from which the result was evaluated based on a defined criterion for moisture safety. The criterion was defined as the maximum accepted water content for wood materials and the highest acceptable moisture accumulation rate in relation to the risk of rot. Based on the criterion, the roof assemblies were certified as being either safe, risky or assumed to fail. The roof assemblies were simulated in different western climates, with varying insulation thicknesses, two different types of wooden decking, applied with varying interior moisture load and with either a high or low solar absorptivity at the roof surface (black or white surface color). The results show that the performance of the studied roof assemblies differs with regard to all of the varying parameters, especially the climate and the indoor moisture load.

  5. Hygrothermal Performance of West Coast Wood Deck Roofing System

    Energy Technology Data Exchange (ETDEWEB)

    Pallin, Simon B [ORNL; Kehrer, Manfred [ORNL; Desjarlais, Andre Omer [ORNL

    2014-02-01

    Simulations of roofing assemblies are necessary in order to understand and adequately predict actual the hygrothermal performance. At the request of GAF, simulations have been setup to verify the difference in performance between white and black roofing membrane colors in relation to critical moisture accumulation for traditional low slope wood deck roofing systems typically deployed in various western U.S. Climate Zones. The performance of these roof assemblies has been simulated in the hygrothermal calculation tool of WUFI, from which the result was evaluated based on a defined criterion for moisture safety. The criterion was defined as the maximum accepted water content for wood materials and the highest acceptable moisture accumulation rate in relation to the risk of rot. Based on the criterion, the roof assemblies were certified as being either safe, risky or assumed to fail. The roof assemblies were simulated in different western climates, with varying insulation thicknesses, two different types of wooden decking, applied with varying interior moisture load and with either a high or low solar absorptivity at the roof surface (black or white surface color). The results show that the performance of the studied roof assemblies differs with regard to all of the varying parameters, especially the climate and the indoor moisture load.

  6. 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...

  7. Corrosion-Resistant Roof with Integrated Photovoltaic Power System

    Science.gov (United States)

    2014-02-01

    metal roof panel are being monitored using a non-operational mockup of a PV module and roofing panel installed on the exposure rack. Four experi...conditions Examination of 1 year’s data downloaded from the corrosion sensors placed between the metal panel and PV module on the system mockup in

  8. The Discharge Coefficient of a Centre-Pivot Roof Window

    DEFF Research Database (Denmark)

    Iqbal, Ahsan; Afshari, Alireza; Nielsen, Peter V.

    2012-01-01

    value of discharge coefficient is used. The constant value of discharge coefficient leads to deceptive airflow estimation in the cases of centre-pivot roof windows. The object of this paper is to study and evaluate the discharge coefficient of the centre pivot roof window. Focus is given...

  9. 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...

  10. Opportunities Green Roofs Can Offer Ghanaians and their Cities

    African Journals Online (AJOL)

    Lone Star College System

    2015-08-17

    Aug 17, 2015 ... Review. Green roofs: A possible best management practice for enhancing the ... development in Ghana in this era of climate change and variability. Key words: Green roof, .... mitigation of urban heat island effect and indoor energy consumption. ..... through buildings, air pollution, emission of greenhouse.

  11. 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

  12. 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.

  13. Spatio-temporal dynamics of solar shading for a parametrically defined roof system

    Energy Technology Data Exchange (ETDEWEB)

    Mardaljevic, J. [Institute of Energy and Sustainable Development (IESD), De Montfort University, The Gateway, Leicester (United Kingdom)

    2004-07-01

    The evaluation of shading devices is generally carried out using a sequence of shadow-pattern images showing the progression of solar penetration for particular times of the day or year. This approach can reveal when solar penetration may occur, say at the summer solstice, but it cannot give a quantitative measure of the degree and likelihood of solar penetration over a representative period of a full year. This paper describes a new image-based technique to quantify the effectiveness of shading devices. It is founded on predictions of direct solar irradiation using hourly meteorological data for a full year. In addition to numerical output, the technique produces synoptic images that reveal the spatial and temporal variation of solar irradiation. There are no practical limits on the scene geometry and buildings with thousands of individual shading elements can be evaluated. The technique is designed to be both fast and highly scalable making it suitable for the evaluation of a large number of design variants. This is demonstrated in the paper using a parametrically defined model of a complex roof shading system based on the Changi Airport Terminal 3 design. The 3600 fins that comprise the roof shading system were generated using a parametric scheme where the fin orientation has a random component. A total of 42 design variants of the roof shading system were evaluated using the new technique. (author)

  14. 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.

  15. 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

  16. Thermal Behavior of Green Roofs Applied to Tropical Climate

    Directory of Open Access Journals (Sweden)

    Grace Tibério Cardoso

    2013-01-01

    Full Text Available The main goal of this paper is to present results on an experimental field about the green roofs thermal behavior, compared to other traditional roof covering systems. On the one hand, it intends to describe shortly the constructive system of a green roof with a lightweight building system, which has a sustainable building materials character and, on the other, it worries with the water reuse and with the run-off delay. The main methodological procedure adopted to study the thermal behavior of green roof was installing thermocouples to collect surface temperatures and indoor air, later comparing them with existing prototypes in an experimental plot. The thermal behavior analysis of cover systems was assessed by a representative episode of the climate fact, based on the dynamic climate approach. The experimental results from internal air temperature measurements show that the green roofs applied to warm and dry climates also provide an interesting time lag with surface and internal air temperature reduction.

  17. 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).

  18. 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.

  19. APPLICATION OF THE ROOF DISTURBANCETO MONITORING AND PREDICTINGTHE GROUND PRESSURE

    Institute of Scientific and Technical Information of China (English)

    付国彬; 钱鸣高

    1992-01-01

    Based on study of the influence of main roof fracture on ground pressure,this paper considered the immediate roof as a semi-infinite long beam on a Winkler elastic foundation. In the model the coal seam is the foundation and the pressure caused by rnian roof deflection is the load.Having solved the model and analyzed relevant factors,the authors indicate that the disturbance caused by the breakage of the mian roof can be observed in both gates of iongwaii face and explain why it can be. The paper points out that the applicability of the method to obtain the disturbance information by measuring the loads on supports is wider than that by measuring the roof convergence rate. The results are useful for monitoring and predicting ground pressure.

  20. Modelling of green roof hydrological performance for urban drainage applications

    DEFF Research Database (Denmark)

    Locatelli, Luca; Mark, Ole; Mikkelsen, Peter Steen

    2014-01-01

    Green roofs are being widely implemented for stormwater management and their impact on the urban hydrological cycle can be evaluated by incorporating them into urban drainage models. This paper presents a model of green roof long term and single event hydrological performance. The model includes...... 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...... and that the mean annual runoff is not linearly related to the storage. Green roofs have therefore the potential to be important parts of future urban stormwater management plans....

  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. 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.

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

    NARCIS (Netherlands)

    Mees, Heleen

    2014-01-01

    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

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

    OpenAIRE

    Nečadová Klára; Selník Petr; Karafiátová Hana

    2017-01-01

    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 additiona...

  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. 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.

  7. Suggestions on building roof waterproofing construction suggestions%建筑屋面防水施工建议

    Institute of Scientific and Technical Information of China (English)

    张海强

    2015-01-01

    从设计、材料、排水、管道四方面分析了建筑屋面出现积水、渗水以及漏水的原因,并深入探讨了建筑屋面防水施工的措施,分析了不同屋面结构防水施工的要求,以选择合理的防水技术,达到良好的防水效果。%The paper analyzes building roof ponding,seepaging and leakaging causes from four aspects of design,materials,drainage and pipe-line,explores building roof waterproofing measures,and analyzes different roof structure waterproofing construction demands,with a view to select rational waterproofing techniques and achieve good waterproofing effect as well.

  8. Dynamic Analysis of Cable Roofs Under Transient Wind:A Comparison Between Time Domain and Frequency Domain Approaches

    Institute of Scientific and Technical Information of China (English)

    S.Ali Ghafari Oskoei; Ghyslaine McClure

    2008-01-01

    At present,high.speed computing capabilities and advanced nonlinear dynamic finite element procedures enable detailed dynamic analysis of cable structures.Although deterministic approaches require considerable analysis time and effort in relation to modeling,running,and data processing,they seem to be the only alternative to obtain high accuracy.Detailed dynamic analysis of cable roof networks is sophisticated and requires advanced modeling expertise.This paper presents a comparison between detailed nonlinear dynamic analysis and a simplified frequency domain approach to estimate the maximum probable response of weakly nonlinear cable roofs.The approach can be considered as alternative to detailed time-domain analysis in the preliminary design phase,or can be used to validate results obtained from more elaborated numerical models.The proposed method is illustrated with two examples of cable net roofs that were also analysed in the time domain.

  9. The green build-out model : quantifying stormwater benefits of trees and green roofs in Washington, DC

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, B.; Whitlow, H. [Casey Trees, Washington, DC (United States); Sullivan, M.; Savineau, A.; Busiek, B. [Limno-Tech Inc., Ann Arbor, MI (United States)

    2007-07-01

    modeling because they can provide stormwater capacity offsets that could have design implications. It was determined that considerable opportunities exist for stormwater benefits from targeted investments in trees and green roofs at the sewershed level. 39 refs., 8 tabs., 6 figs.

  10. Drawing green in New York city : aesthetic design and sustainable development

    Energy Technology Data Exchange (ETDEWEB)

    Wayland-Smith, S. [Balmori Associates Inc., New York, NY (United States)

    2005-07-01

    Strong aesthetic design can advance the development of the green roof industry in the United States. Many architects are beginning to adopt green roofs as a design element that merges architecture and landscapes in sustainable systems. Innovative design of green roofs will draw attention to the technology and create momentum for the green roof movement, which may lead to more incentives and policy programs. With the development of a range of watertight membranes, geotextiles and specific soil substrates, the idea of merging landscape and architecture within a single structure is now a more viable and efficient reality. Design intent needs to be clearly illustrated. This paper provided an outline of the philosophy and practices of Balmori, a green roof design firm that envisions the rooftops of New York City as a potential second central park. Green roofs designed by the organization to date include the Solaire building roof garden; a green roof network in Long Island; the Gratz Industries and Silvercup Studios roof projects; and a new residential green roof for a building in Manhattan. Details of funding, partnerships and technical specifications were provided for each project. Descriptions of the completed and ongoing projects were used to illustrate Balmori's philosophy of promoting sustainable green roofs that alter their urban context through aesthetic means. It was concluded that it is only when green roof technologies are conceived as being powerful design tools as opposed to ecological experiments will their widespread adoption occur.1 ref., 4 figs.

  11. 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.

  12. Adventures on the roof of the world

    Science.gov (United States)

    Leslie,, David M.

    2013-01-01

    To conduct field biology requires tenacity, grit, and flexibility; to endeavor to achieve conservation success requires patience, persistence, and passion. The essence of field biology and the hope for conservation success are both reflected admirably in George B. Schaller's most recent book, Tibet Wild: A Naturalist's Journeys on the Roof of the World. I can think of no living biologist who embodies these characteristics more than Schaller does. Nearly 80 years old, he still regularly treks in faraway lands, observing and recording the natural history of species that the vast majority of us will never see in the wild. Schaller is a vanguard, and Tibet Wild, like his other books, is a sentinel of urgent conservation need.

  13. Precast Prestressed Concrete Truss-Girder for Roof Applications

    Directory of Open Access Journals (Sweden)

    Peter Samir

    2014-01-01

    Full Text Available Steel trusses are the most popular system for supporting long-span roofs in commercial buildings, such as warehouses and aircraft hangars. There are several advantages of steel trusses, such as lightweight, ease of handling and erection, and geometric flexibility. However, they have some drawbacks, such as high material and maintenance cost, and low fire resistance. In this paper, a precast concrete truss is proposed as an alternative to steel trusses for spans up to 48 m (160 ft without intermediate supports. The proposed design is easy to produce and has lower construction and maintenance costs than steel trusses. The truss consists of two segments that are formed using standard bridge girder forms with block-outs in the web which result in having diagonals and vertical members and reduces girder weight. The two segments are then connected using a wet joint and post-tensioned longitudinally to form a crowned truss. The proposed design optimizes the truss-girder member locations, cross-sections, and material use. A 9 m (30 ft long truss specimen is constructed using self-consolidated concrete to investigate the constructability and structural capacity of the proposed design. A finite element analysis of the specimen is conducted to investigate stresses at truss diagonals, verticals, and connections. Testing results indicate the production and structural efficiency of the developed system.

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

    Science.gov (United States)

    Epstein, Scott A.; Lee, Sang-Mi; Katzenstein, Aaron S.; Carreras-Sospedra, Marc; Zhang, Xinqiu; Farina, Salvatore C.; Vahmani, Pouya; Fine, Philip M.; Ban-Weiss, George

    2017-08-01

    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 California’s Title 24 building energy efficiency standards within the heavily populated and polluted South Coast Air Basin (SoCAB). Development of a comprehensive rooftop area database and evaluation of spectral reflectance measurements of roofing materials allows us to project potential future changes in solar and UV reflectance for simulations using the Weather Research Forecast and Community Multiscale Air Quality (CMAQ) models. 2012 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.

  15. 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-).

  16. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tsakovski, Stefan, E-mail: stsakovski@chem.uni-sofia.b [Chair of Physical Chemistry, Faculty of Chemistry, University of Sofia, J Bourchier Blvd. 1, 1164 Sofia (Bulgaria); Tobiszewski, Marek [Department of Analytical Chemistry, Chemical Faculty, Gdansk University of Technology (GUT), 11/12 G. Narutowicza St., 80-952 Gdansk (Poland); Simeonov, Vasil, E-mail: vsimeonov@chem.uni-sofia.b [Chair of Analytical Chemistry, Faculty of Chemistry, University of Sofia, 1164 Sofia (Bulgaria); Polkowska, Zaneta [Department of Analytical Chemistry, Chemical Faculty, Gdansk University of Technology (GUT), 11/12 G. Narutowicza St., 80-952 Gdansk (Poland); Namiesnik, Jacek, E-mail: chemanal@pg.gda.p [Department of Analytical Chemistry, Chemical Faculty, Gdansk University of Technology (GUT), 11/12 G. Narutowicza St., 80-952 Gdansk (Poland)

    2010-01-15

    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.

  18. 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.

  19. 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.

  20. Cool roofs as an energy conservation measure for federal buildings

    Energy Technology Data Exchange (ETDEWEB)

    Taha, Haider; Akbari, Hashem

    2003-04-07

    We have developed initial estimates of the potential benefits of cool roofs on federal buildings and facilities (building scale) as well as extrapolated the results to all national facilities under the administration of the Federal Energy Management Program (FEMP). In addition, a spreadsheet ''calculator'' is devised to help FEMP estimate potential energy and cost savings of cool roof projects. Based on calculations for an average insulation level of R-11 for roofs, it is estimated that nationwide annual savings in energy costs will amount to $16M and $32M for two scenarios of increased roof albedo (moderate and high increases), respectively. These savings, corresponding to about 3.8 percent and 7.5 percent of the base energy costs for FEMP facilities, include the increased heating energy use (penalties) in winter. To keep the cost of conserved energy (CCE) under $0.08 kWh-1 as a nationwide average, the calculations suggest that the incremental cost for cool roofs should not exceed $0.06 ft-2, assuming that cool roofs have the same life span as their non-cool counterparts. However, cool roofs usually have extended life spans, e.g., 15-30 years versus 10 years for conventional roofs, and if the costs of re-roofing are also factored in, the cutoff incremental cost to keep CCE under $0.08 kWh-1 can be much higher. In between these two ends, there is of course a range of various combinations and options.

  1. 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

  2. Additive effects of aboveground polyphagous herbivores and soil feedback in native and range-expanding exotic plants

    NARCIS (Netherlands)

    Morrien, W.E.; Engelkes, T.; Putten, van der W.H.

    2011-01-01

    Plant biomass and plant abundance can be controlled by aboveground and belowground natural enemies. However, little is known about how the aboveground and belowground enemy effects may add up. We exposed 15 plant species to aboveground polyphagous insect herbivores and feedback effects from the soil

  3. Vehicle roof with solar power supply and contact device. Fahrzeugdach mit Solarstromquelle und Kontakteinrichtung

    Energy Technology Data Exchange (ETDEWEB)

    Paetz, W.; Meiler, K.; Schumacher, T.; Bienert, H.; Hirschberger, A.; Pfisterer, H.; Hoeller, M.

    1991-05-02

    Vehicle roof with at least one cover, carrying a solar power supply for optional covering or at least for partial uncovering of a roof opening. In addition, with at least one load driven by the solar power supply which is arranged separately from the cover and with a contact device for establishing of an electric connection between the solar power supply and the load. The contact device is designed as a switching configuration and the cover is a part of this switching configuration, so that depending on the adjustment motion of the cover, the load is connected to the solar power supply in one or several predetermined cover positions, and is disconnected in all other covert positions.

  4. Roofing waterproof Engineering%浅谈屋面防水工程

    Institute of Scientific and Technical Information of China (English)

    黄萍

    2012-01-01

      屋面防水工程是一个系统工程,若想解决防水的防渗问题,就要从工程的设计选材、施工及维修管理着手,综合管理,严格控制,以提高防水工程质量,增强防水效果,延长屋面防水使用寿命。%  roofing waterproof project is project of a system, to solve the water seepage problem, must from the engineering design material selection, construction and repair management to begin, comprehensive management, strict control, in order to improve the quality of waterproof engineering, reinforced waterproof effect, prolonging the service life of the roofing waterproof.

  5. Characteristics of wind pressure pulse on large-span flat roofs

    Institute of Scientific and Technical Information of China (English)

    SUN Ying; CAO Zheng-gang; WU Yue

    2009-01-01

    The wind pressure pulse events, among the most important characteristics of wind pressure fluctuations on large-span fiat roofs, were investigated by wind tunnel tests in this paper. Incorporating the formation mechanism of wind pressure pulse events, the peak over threshold method was employed to study properties of this kind of events. The event duration time, the energy contribution, the number of the pulse events, and the distribution of average peak pressure were calculated. Probability density functions of some typical samples in separation region were also given. Results show that the non-Gaussian roof pressure is strong in the flow separa tion region owing to the wind pressure pulse events. Evaluations of the extreme peak pressures, which can be determined by the peak over threshold method effectively, are important to the design of building cladding.

  6. 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.

  7. The effects of green roofs in a sub-tropical system

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, M. [Austin Univ., Austin, TX (United States). Lady Bird Johnson Wildflower Center; Gardiner, B. [Austech Roof Consultants Inc., Austin, TX (United States)

    2007-07-01

    The building and environmental benefits of green roofs in non-temperate, or subtropical systems were discussed. Since there are greater climatic extremes in such systems, green roofs may offer more benefits. Most green roof research has focused on the use of succulent plants due to their low water demand and slow growth rates. The Lady Bird Johnson Wildflower Center and the Roof Consultants Institute Foundation are conducting joint research project to assess the suitability of native vegetation for use on extensive green roofs in central Texas. The project examined the effects of green roofing in a subtropical climate and the thermal properties of buildings, stormwater runoff rates, water quality, and irrigation requirements. Stormwater retention capacity of green roofs and water quality of stormwater runoff was compared to conventional roofs. The growing media that are most successful for this particular ecoregion was also identified. The focus on native plants in this study identified the characteristics of climatic adaptation, which may help to reduce total water and nutrient demand, and avoid problems associated with the introduction of potentially invasive species. The study compared performance of 6 types of green roofs and two types of traditional roof materials using simulated roof platforms. During the hottest days in August, roof membrane temperatures on the green roofs were 10 degrees C cooler than white roofs and 40 degrees C cooler than conventional black roofs. It was concluded that the temperature and water quantity characteristics of green roofs are advantageous in subtropical climates. 4 refs., 1 tab., 4 figs.

  8. Specifying, Installing and Maintaining Built-Up and Modified Bitumen Roofing Systems.

    Science.gov (United States)

    Hobson, Joseph W.

    2000-01-01

    Examines built-up, modified bitumen, and hybrid combinations of the two roofing systems and offers advise on how to assure high- quality performance and durability when using them. Included is a glossary of commercial roofing terms and asphalt roofing resources to aid in making decisions on roofing and systems product selection. (GR)

  9. 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

  10. Cool Roofs to Save Money and Delay Global Warming

    Science.gov (United States)

    Rosenfeld, Arthur

    2006-04-01

    White roofs, and now cool-colored roofs, with a high reflectivity or `albedo' have a long history (best known around the Mediterranean) of keeping buildings and cities cool. In modern times, cool roofs have been shown to reduce air conditioning (a-c) demand and slow the formation of ozone (smog). Studies establishing a typical 10% reduction in a-c demand and electricity savings due to white roofs in California (CA) resulted in the 2005 CA new building energy efficiency standard prescribing that low-slope roofs be white, but exempting sloping roofs for aesthetic reasons. The advent (thanks to physicists' efforts) of inexpensive colored pigments with high albedo has led to 2008 CA standards requiring that even sloping roofs be cool. Here, I show that cooling the planet by reducing urban albedo through white and other cool roofs is a direct effect, much larger and immediate than the 2nd-order cooling from reduced CO2 from reduced a-c use. I then investigate widespread deployment of cool roof in major tropical and temperate cities, which cover 2% of global land area and have a proportionately higher albedo impact due to lower latitude. Here, cool roofs and cooler pavements can raise urban albedo by 10%. This directly drops the global average temperature by ˜0.05 /deg C. Though small compared to a likely 3 /deg C rise by 2060, an immediate drop of 0.05 /deg C represents a reprieve in global warming of 1 year, and represents avoiding a year's current annual world emissions of CO2, i.e. 25 GT(CO2). At a trading price of 25/tCO2, this is worth ˜625B. Cooling the planet also could save annually hundreds of billions on a-c electric bills. Finally I suggest policies to increase cool roof deployment, for example, developed world Kyoto signatories could use its CDM (Clean Development Mechanism) for cool roof programs in developing countries.

  11. 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.

  12. Entry roof truss-bolt system test under the gob of contiguous seams

    Institute of Scientific and Technical Information of China (English)

    LIAN Chuan-jie; XU Wei-ya; WANG Ya-jie

    2007-01-01

    Roof bolt support system has been widely applied in the No.7.9 seam in Caozhuang coal mine.However,it has not been able to be applied in the NO.10-2 seam since the small interburden(2m)between NO.9 and NO.10-2 seam.The NO.9 and NO.10-2 seams are contiguous seams.The NO.9 seam has been mined out and the NO.10-2 seam will be mined under the gob of the NO.9 seam.The roof strata of the NO.10-2 seam may have been weakened and fractured due to the shear failure caused by the NO.9 seam mining activities.The steel beam sets spaced at 0.8 m have been used to support the entry of the NO.10-2 seam.In order to speed up the advance rate and cut entry development cost,a test area,using roof bolt in conjunction with truss-system,was successfully conducted.This paper presents the support system design,application of designed system,and the test results.Test results provide a cheaper,quicker,and safer way to support entry for the No.10-2 seam.

  13. 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.

  14. Roof structure theory and support resistance determination of longwall face in shallow seam

    Institute of Scientific and Technical Information of China (English)

    HUANG Qing-xiang(黄庆享)

    2003-01-01

    This paper presents the structure models founded in shallow seam, the roof asymmetry arch with three articulations in roof first weighting and the step voussoir beam in roof periodic weighting. These structure models are differ from classic theory, it establishes the new roof control theory of instability structure roof, especially in shallow seam. Based on the new roof structure theory, the support working state of "given sliding load" is put forward, and the factor of load transmitting is introduced to determine the load on roof structure. Therefore, the proper and accurate calculating methods of support resistance are established. Based on this, the dynamic structure theory in shallow seam could be predicted.

  15. 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 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.

  16. [Effects of shading on the aboveground biomass and stiochiometry characteristics of Medicago sativa].

    Science.gov (United States)

    Ma, Zhi-Liang; Yang, Wan-Qin; Wu, Fu-Zhong; Gao, Shun

    2014-11-01

    In order to provide scientific basis for inter-planting alfalfa in abandoned farmland, a shading experiment was conducted to simulate the effects of different light intensities on the aboveground biomass, the contents of carbon, nitrogen, phosphorus and potassium, and the stoichiometric characteristics of alfalfa under the plantation. The results showed that the aboveground biomass of alfalfa correlated significantly with the light intensity, and shading treatment reduced the aboveground biomass of alfalfa significantly. The aboveground alfalfa tissues under the 62% shading treatment had the highest contents of carbon, nitrogen and phosphorus, which was 373.73, 34.38 and 5.47 g · kg(-1), respectively, and significantly higher than those of the control. However, shading treatments had no significant effect on the potassium content of aboveground part. The C/N ratio in aboveground tissues under the 72% shading treatment was significantly higher than that of the control, but no significant differences among other treatments were found. The ratios of N/P and C/P in aboveground tissues showed a tendency that decreased firstly and then increased with the increase of light intensity.

  17. The Feasibility of Installing and Monitoring an Extensive Green Roof at Purdue University

    OpenAIRE

    2007-01-01

    The Boiler Green Initiative (BGI) is a student-run organization working to improve environmental sustainability at the Purdue University West Lafayette campus. A main goal of BGI's is to install a green roof on an existing building on campus that is being replaced. We discuss the benefits of green roofs, the feasibility of having one installed on the Armory's roof and the various monitoring options we have researched. Flat roofs are especially amenable to the green roof system, so a building ...

  18. 拱顶罐设计压力对低压火炬管网系统的影响%The Impact of Dome Roof Oil Tanks Design Pressure on Low Pressure Flare pipeline System

    Institute of Scientific and Technical Information of China (English)

    陆海

    2016-01-01

    伊朗北阿项目原油脱气塔、原油拱顶罐和污水沉降罐等设备气出口通过火炬管网连接至低压火炬,最远端设备距离火炬约500 m。原FEED设计中拱顶罐设计压力为0.002 MPa(G),受大罐背压影响,低压火炬系统需较大管径;在详细设计中采纳国际知名设计咨询商的审查意见,提高拱顶罐设计压力到0.004 MPa(G)。通过计算两种不同设计压力条件下大罐主体工程量,在此基础上计算了两种不同设计压力条件下低压火炬管网系统管径,经技术和经济对比分析认为,将拱顶罐的设计压力从0.002 MPa(G)提高到了0.004 MPa(G),节约成本约82.8万美元,具有可行性和经济性,值得推广和应用。%The air outlets of degassing tower, oil tanks and produced water sedimentation tanks are connected to low pressure flare network in North Azadegan Oilfield development project.The most remote equipment is about 500 meters away from the flare stack.The de-signing pressure of oil tanks is 0.002 MPag in FEED design stage. Affected by the back pres-sure of oil tanks, the pipe size of low pressure flare system should be very large correspond-ingly. According to the recommendation of world famous engineering consulters, the design pressure of tanks was changed to be 0.004 MPag in the detailed engineering stage. Through detailed calculation of the pipe size of low pressure flare network and work load of those tanks, the economic analysis shows that if the design pressure of oil tanks was changed from 0.002 MPag to 0.004 MPag, the costs could be saved 828 thousand U.S.dollar, and the de-sign is more economical and worth to be popularized and applied.

  19. 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...

  20. Roof Isolation System - A Vibration Absorber for Buildings

    Institute of Scientific and Technical Information of China (English)

    田志昌; 钱稼茹

    2001-01-01

    A roof isolation system is proposed to reduce the dynamic response of buildings to earthquake excitations. In the system, frictional materials are inserted between the roof slab and the beams that support the slab. The roof slab and the beams are connected by springs. The optimum stiffness of the system is determined to minimize the seismic response of the buildings. A comparative study of the responses of an eight-story frame structure with and without the proposed system to ground motions was carried out to assess the system effectiveness. The study showed that the system energy dissipation capacity is nonlinear. The effectiveness of the system is related to the frequency and the acceleration of the ground motion. The system reduces the maximum lateral displacement response and the maximum inter-story drift response of the building by as much as 45% except for the roof.

  1. Experimental measurements and numerical modelling of a green roof

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, Renato M.; Castellotti, Francesco; Busato, Filippo [Padova Univ., Dept. of Management and Engineering, Vicenza (Italy)

    2005-12-15

    Green roof utilisation has been known since ancient times both in hot and cold climates. Nowadays, it has been reconsidered at issue of energy saving and pollution reduction. In this paper, some measurement sessions on a green roof installed by the Vicenza Hospital are described. A data logging system with temperature, humidity, rainfall, radiation, etc. sensors surveyed both the parameters related to the green roof and to the rooms underneath. The aim is to evaluate the passive cooling, stressing the evapotranspiration role in summer time. Furthermore, the enhanced insulating properties have been tested during winter time. A predictive numerical model has been developed in a building simulation software (TRNSYS) to calculate thermal and energy performances of a building with a green roof, varying the meteorological dataset for a specific geographic zone. (Author)

  2. Variability of Rain Water Quality due to Roof Characteristics | Utsev ...

    African Journals Online (AJOL)

    Variability of Rain Water Quality due to Roof Characteristics. ... is receiving increased attention worldwide as an alternative source of drinking water. ... as grey water for domestic purposes but requires treatment to be used as drinking water.

  3. 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.

  4. High Alumina Refractory Bricks for Electric Arc Furnace Roofs

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ 1 Scope This standard specifies the sort, technical requirement, test method, inspection rules, marking, packing, transportation, storage and quality certification of high alumina refractory bricks for electric arc furnace roofs.

  5. Green roofs: A possible best management practice for enhancing ...

    African Journals Online (AJOL)

    ... roofs: A possible best management practice for enhancing the environmental quality ... erodes the natural ability of the locale to perform its ecosystem services. ... structural components, formulation of guidelines for the industry, government ...

  6. Home advantage in retractable-roof baseball stadia.

    Science.gov (United States)

    Romanowich, Paul

    2012-10-01

    This study examined whether the home advantage varies for open-air, domed, or retractable-roof baseball stadia, and whether having the roof open or closed affects the home advantage in retractable-roof baseball stadia. Data from Major League Baseball (MLB) games played between 2001 and 2009 were analyzed for whether or not the presence of a home-advantage was dependent on the type of home stadium used. Home advantage was robust for all three types of stadia. A significant effect of stadium type on home advantage was found, with a greater home advantage for teams playing home games in domed stadia relative to open-air stadia, replicating a previous study. There was a greater home advantage for teams playing home games in domed stadia relative to retractable-roof stadia. No other differences in the home advantage were found; results are discussed in terms of familiarity with the facility.

  7. 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

  8. How EPA's Asbestos Regulations Apply to Roofing Materials

    Science.gov (United States)

    Guidance Manual and letters that clarify the applicability of the asbestos National Emissions Standard for Hazardous Air Pollutants (NESHAP) to the removal of asbestos-containing roofing material including tiles, and piping during demolition

  9. 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.

  10. Analysis of mechanism of shock bump due to roof fall

    Institute of Scientific and Technical Information of China (English)

    GU Xin-jian; LI Jian-xiong

    2004-01-01

    According to the characteristics of the shock bump due to roof fall, a simple mechanics model has been established by applying the catastrophic theory and the law of energy conservation. The author suggests that the shock bump may be induced by the sudden energy release in the roof falling after underground mineral extractions, and through the systematic analysis of actual examples on site, the empirical formulae for the roof falling and energy release are derived, which would provide a new way for the study of the origin and mechanism of mine tremor due to fallen-in roof structure. It is of a great importance to enrich the shock bump theory and production safety in mine.

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

    Directory of Open Access Journals (Sweden)

    Gavrilović Dragan J.

    2011-01-01

    Full Text Available 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" takes on a new, additional energy function, which proves the ability to reduce overall energy consumption of total conventional seasonal heating and cooling consumption of a building. Supporting of this intention, the paper gives a variant solution of an easily prefabricated reinforced concrete roof system of shallow water pool that works on the principle of passive solar energy capture.

  12. 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

  13. MODELING OF STORM WATER RUNOFF FROM GREEN ROOFS

    OpenAIRE

    Ewa Burszta-Adamiak; Wiesław Fiałkiewicz

    2014-01-01

    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 ...

  14. 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.

  15. The gastrocoel roof plate in embryos of different frogs.

    Science.gov (United States)

    Sáenz-Ponce, Natalia; Santillana-Ortiz, Juan-Diego; del Pino, Eugenia M

    2012-02-01

    The morphology of the gastrocoel roof plate and the presence of cilia in this structure were examined in embryos of four species of frogs. Embryos of Ceratophrys stolzmanni (Ceratophryidae) and Engystomops randi (Leiuperidae) develop rapidly, provide comparison for the analysis of gastrocoel roof plate development in the slow-developing embryos of Epipedobates machalilla (Dendrobatidae) and Gastrotheca riobambae (Hemiphractidae). Embryos of the analyzed frogs develop from eggs of different sizes, and display different reproductive and developmental strategies. In particular, dorsal convergence and extension and archenteron elongation begin during gastrulation in embryos of rapidly developing frogs, as in Xenopus laevis. In contrast, cells that involute during gastrulation are stored in the large circumblastoporal collar that develops around the closed blastopore in embryos of slow-developing frogs. Dorsal convergence and extension only start after blastopore closure in slow-developing frog embryos. However, in the neurulae, a gastrocoel roof plate develops, despite the accumulation of superficial mesodermal cells in the circumblastoporal collar. Embryos of all four species develop a ciliated gastrocoel roof plate at the beginning of neurulation. Accordingly, fluid-flow across the gastrocoel roof plate is likely the mechanism of left-right asymmetry patterning in these frogs, as in X. laevis and other vertebrates. A ciliated gastrocoel roof plate, with a likely origin as superficial mesoderm, is conserved in frogs belonging to four different families and with different modes of gastrulation.

  16. 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.

  17. Proposed Measures to Protect Temporary Roofs from Unwanted Heat Gains

    Directory of Open Access Journals (Sweden)

    Omar S. Asfour

    2017-06-01

    Full Text Available This study focuses on the uncompleted multi-storey residential buildings located in hot climates. This construction pattern is common in the case of incremental housing, where additional floors are added to the building as housing needs grow. Top roofs in these buildings are usually left without thermal insulation until the rest of upper floors are erected. This causes higher thermal discomfort in the top flats compared to the lower ones. Thus, the aim of this study is to investigate thermal effect of some proposed temporary measures that are intended to protect these roofs from unwanted heat gains until the rest of storeys are constructed. This has been carried out using thermal modelling to find out the effect of these measures on the amount of heat transfer through the roof in both summer and winter times. The analysis showed that it is possible to achieve competent thermal protection of the top roof compared to the layered thermal insulation using simple, cost-effective, and reversible measures. Among the examined measures, covering the roof with white foldable sheets and the use of pergolas have been found to be the most effective measures. In both cases, a reduction of 38% in conductive heat transfer through the top roof in summer was observed compared to the unprotected modelling case.

  18. Global patterns of aboveground carbon stock and sequestration in mangroves.

    Science.gov (United States)

    Estrada, Gustavo C D; Soares, Mário L G

    2017-01-01

    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 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.

  19. 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.

  20. Aboveground to belowground herbivore defense signaling in maize

    Science.gov (United States)

    Gill, Torrence; Zhu, Lixue; Lopéz, Lorena; Pechanova, Olga; Shivaji, Renuka; Ankala, Arunkanth; Williams, W. Paul

    2011-01-01

    Insect pests that attempt to feed on the caterpillar-resistant maize genotype Mp708 encounter a potent, multipronged defense system that thwarts their invasion. First, these plants are on “constant alert” due to constitutively elevated levels of the phytohormone jasmonic acid that signals the plant to activate its defenses. The higher jasmonic acid levels trigger the expression of defense genes prior to herbivore attack so the plants are “primed” and respond with a faster and stronger defense. The second defense is the rapid accumulation of a toxic cysteine protease called Mir1-CP in the maize whorl in response to caterpillar feeding. When caterpillars ingest Mir1-CP, it damages the insect's midgut and retards their growth. In this article, we discuss a third possible defense strategy employed by Mp708. We have shown that foliar caterpillar feeding causes Mir1-CP and defense gene transcripts to accumulate in its roots. We propose that caterpillar feeding aboveground sends a signal belowground via the phloem that results in Mir1-CP accumulation in the roots. We also postulate that the roots serve as a reservoir of Mir1-CP that can be mobilized to the whorl in response to caterpillar assault. PMID:21270535

  1. Regional Mapping, Modelling, and Monitoring of Tree Aboveground Biomass Carbon

    Science.gov (United States)

    Hudak, Andrew

    2016-04-01

    Airborne lidar collections are preferred for mapping aboveground biomass carbon (AGBC), while historical Landsat imagery are preferred for monitoring decadal scale forest cover change. Our modelling approach tracks AGBC change regionally using Landsat time series metrics; training areas are defined by airborne lidar extents within which AGBC is accurately mapped with high confidence. Geospatial topographic and climate layers are also included in the predictive model. Validation is accomplished using systematically sampled Forest Inventory and Analysis (FIA) plot data that have been independently collected, processed and summarized at the county level. Our goal is to demonstrate that spatially and temporally aggregated annual AGBC map predictions show no bias when compared to annual county-level summaries across the Northwest USA. A prominent source of bias is trees outside forest; much of the more arid portions of our study area meet the FIA definition of non-forest because the tree cover does not exceed their minimum tree cover threshold. We employ detailed tree cover maps derived from high-resolution aerial imagery to extend our AGBC predictions into non-forest areas. We also employ Landsat-derived annual disturbance maps into our mapped AGBC predictions prior to aggregation and validation.

  2. 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.

  3. 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.

  4. The vapor diffusion resistance and air permeance of masonry and roofing systems

    Energy Technology Data Exchange (ETDEWEB)

    Hens, Hugo S.L.C. [Laboratory of Building Physics, Department of Civil Engineering, University of Leuven, Kasteelpark Arenberg, 51, 3001 Leuven (Belgium)

    2006-06-15

    Several building parts contain layers composed of separate elements that are mortared together or simply interlock or overlap. Typical examples are masonry walls, brick veneers, tiled roofing systems and slated roofing systems. The mortar joints, the interlocks and overlaps should affect the water vapor diffusion resistance and the air permeance of the composite layer, at least in comparison with the vapor and air flow properties of the pure elements. However, little information is found in literature that allows a quantification of the differences. The article describes a purpose designed test method for measuring the water vapor diffusion resistance of composite layers. It comments on the results and also gives data for the air permeances, measured with a pressure box. From the results and data, it is clear that mortared joints, interlocks and overlaps decrease the water vapor diffusion resistance and increase the air permeance of a composite layer compared to the pure material. In fact, mortared joints, interlocks and overlaps act as preferential paths for water vapor and air mitigation. As a consequence, using composite layers as outside finish in thermally insulated building parts, as done in pitched roofs and cavity walls, diminishes the interstitial condensation risk, accelerates drying of the cladding when wetted by wind-driven rain and affects the effectiveness of outside air cross ventilation below or behind the finish. (author)

  5. Root-fed Salicylic Acid in Grape Involves the Response Caused by Aboveground High Temperature

    Institute of Scientific and Technical Information of China (English)

    Hong-Tao Liu; Yue-Ping Liu; Wei-Dong Huang

    2008-01-01

    In order to investigate the transportation and distribution of salicylic acid (SA) from root to aboveground tissues in response to high temperature, the roots of grape plant were fed with 14C-SA before high temperature treatment. Radioactivity results showed that progressive increase in SA transportation from root to aboveground as compared with the control varied exactly with the heat treatment time. Radioactivity results of leaves at different stem heights indicated that the increase in SA amount at the top and middle leaves during the early period was most significant in comparison with the bottom leaves. The up-transportation of SA from root to aboveground tissues was dependent on xylem rather than phloem. Auto-radiographs of whole grape plants strongly approved the conclusions drawn above. Root-derived SA was believed to be a fundamental source in response to aboveground high temperature.

  6. Design and Construction of the High Template of the Ring Beam of the Coal Bunker Roof%煤仓顶环梁高支模的设计与施工

    Institute of Scientific and Technical Information of China (English)

    柯潮彬

    2014-01-01

    高大模板是工程实践中的重点和难度,也是工程质量和安全控制的重点。本文主要结合广州某电厂煤仓顶环梁的施工,介绍了高支模的设计和施工管理的措施,确保了高支模结构具有足够的承载力、刚度和稳定性。%Tal template is the focus and difficulty in en- gineering practice and it is also the important point of the quality and safety control in engineering. Combined with the construction of the ring beam of a power plant coal bunker in Guangzhou, this paper mainly introduced the design and co- nstruction management measures of the tal template , ensuring the tal template structure has enough bearing capacity, rigidity and stability.

  7. 高大空间膜结构屋顶展厅置换通风空调设计%Displacement ventilation air conditioning design of a large space pavilion with membrane roof

    Institute of Scientific and Technical Information of China (English)

    王翔; 王亮

    2012-01-01

    Presents the design of a Shanghai Expo pavilion project, calculates the supply flow rate with the displacement ventilation CFD predictive equation deduced by Professor Chen Qingyan. Simulates and optimizes the temperature and air velocity distribution, and tests the temperature during the operating. Draws a conclusion that the project can be one case to predict supply flow rate in large space by using Chen's CFD predictive equation.%介绍了上海世博会某膜结构屋顶展厅的置换通风空调设计,采用陈清焰置换通风CFD模拟公式计算了送风量.对室内温度场、速度场进行了模拟及优化,并在运行期间进行了温度实测.结论是本项目可作为陈氏置换通风CFD模拟公式应用于大空间尺度的一个案例.

  8. Fracturing characteristics of main roof strata when mining uphill and downhill and its effect on stability of immediate roof

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Q.; Liu, J.; Zhang, Y. (Shanxi Mining Institute (China))

    1994-04-01

    The main roof strata in uphill and downhill mining of an inclined longwall may be regarded as an elastic plate. When the ratio of longwall and short span is greater than 2, the load is mainly carried by the short span. Based on this, the authors take a unit width of an inclined rock beam in the direction of face advance and a mechanical model for studying initial and periodic weighting of the main roof was established. It shows that the interval of periodic weighting and abutment pressure in uphill mining are less than that of downhill mining and the distribution of abutment pressure in both cases is quite different. Manifestation of ground pressure in uphill mining is more evident than downhill mining. It is proved that when uphill mining is introduced, the immediate roof is less stable and roof failures are frequent due to stress component in the direction of rock strata and to spalling of coal rib. When the direction of stress component is the same as face advance, the immediate roof is more stable and vice versa if the contrary. From the roof control point of view, where conditions are favourable, priority should be given to downhill mining. 4 refs., 11 figs., 1 tab.

  9. Interrelated effects of mycorrhiza and free-living nitrogen fixers cascade up to aboveground herbivores

    OpenAIRE

    Khaitov, Botir; Patiño Ruiz, José David; Pina Desfilis, María Tatiana; Schausberger, Peter

    2015-01-01

    Aboveground plant performance is strongly influenced by belowground microorganisms, some of which are pathogenic and have negative effects, while others, such as nitrogen-fixing bacteria and arbuscular mycorrhizal fungi, usually have positive effects. Recent research revealed that belowground interactions between plants and functionally distinct groups of microorganisms cascade up to aboveground plant associates such as herbivores and their natural enemies. However, while functionally distinc...

  10. [Relationships between aboveground biomass and environmental factors along an altitude gradient of alpine grassland].

    Science.gov (United States)

    Li, Kai-Hui; Hu, Yu-Kun; Wang, Xin; Fan, Yong-Gang; Wu-Maier, Wu-Shou

    2007-09-01

    In order to analyze the relationships between aboveground biomass and environmental factors along an altitude gradient of Bayanbulak alpine grassland on the southern slope of Tianshan Mountain, nine plots were selected, with each at 100 m interval of altitude. The results showed that Stipa purpurea and Festuca ovina communities distributed at the altitude from 2460 to 2760 m, and the aboveground biomass were 52.2-75.9 g x m(-2). Kobresia capillifolia + S. purpurea communities distributed at altitude 2860 m, and the aboveground biomass was 53.2 g x m(-2). K. capillifolia, Aichemilla tianschanica and Carex stenocarpa distributed at the altitude from 2860 to 3260 m, and the aboveground biomass was 62.1-107.4 g x m(-2). The mean relative humidity in July and August had greater effects on the aboveground biomass. Altitude had a negative correlation with the aboveground biomass of gramineous functional group, but a positive correlation with that of sedge functional group. The mean air temperature in July and August was the key factor affecting the aboveground biomass of gramineous and sedge functional groups, and the stepwise regression equations were Y = 13.467X - 97.284 and Y = 171.699 - 15.331X, respectively (X represented mean air temperature, and Y represented aboveground biomass). Altitude was negatively correlated with mean air temperature and soil pH value (P < 0.01), and positively correlated with mean relative humidity (P < 0.01) and soil available nitrogen and water content (P < 0.05).

  11. 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.

  12. [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).

  13. Intermediate coupling between aboveground and belowground biomass maximises the persistence of grasslands.

    Science.gov (United States)

    Scheiter, Simon; Higgins, Steven I

    2013-01-01

    Aboveground and belowground biomass compartments of vegetation fulfil different functions and they are coupled by complex interactions. These compartments exchange water, carbon and nutrients and the belowground biomass compartment has the capacity to buffer vegetation dynamics when aboveground biomass is removed by disturbances such as herbivory or fire. However, despite their importance, root-shoot interactions are often ignored in more heuristic vegetation models. Here, we present a simple two-compartment grassland model that couples aboveground and belowground biomass. In this model, the growth of belowground biomass is influenced by aboveground biomass and the growth of aboveground biomass is influenced by belowground biomass. We used the model to explore how the dynamics of a grassland ecosystem are influenced by fire and grazing. We show that the grassland system is most persistent at intermediate levels of aboveground-belowground coupling. In this situation, the system can sustain more extreme fire or grazing regimes than in the case of strong coupling. In contrast, the productivity of the system is maximised at high levels of coupling. Our analysis suggests that the yield of a grassland ecosystem is maximised when coupling is strong, however, the intensity of disturbance that can be sustained increases dramatically when coupling is intermediate. Hence, the model predicts that intermediate coupling should be selected for as it maximises the chances of persistence in disturbance driven ecosystems.

  14. 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

  15. 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.

  16. Evaluation of solar energy on the roofs of livestock houses

    Directory of Open Access Journals (Sweden)

    Paolo Liberati

    2013-03-01

    Full Text Available There is a great potential for production of thermal and electrical energy by means of solar collectors on farms. To assess in advance the performance of the alternative plant solutions, a computational model for the determination of solar energy absorbed by surfaces with different exposures as a function of latitude, day, orientation and inclination has been created. Its application to roofs of buildings typically used for animal housing is presented; these were mono-pitch, gabled, and shed type roofs. For each building, the annual energy absorption per unit of floor area is calculated by varying orientation and slope of the pitches. For roof surfaces exposed only in one direction (mono-pitch or shed, the orientation is shown to be a dominant factor with respect to the slope in determining the annual energy uptake. The maximum uptake is obtained with exposure to the south and is greater the higher the slope (up to 67.5%. For gabled roofs, the total uptake is negatively affected by the worse exposed pitch and does not vary significantly, for a given slope, with orientation (up to 2.8%. The maximum gain is obtained with the optimal building azimuth (0° and the highest slope. The shed type, since it is affected by the shade induced by the upper pitch over the lower, cannot reach the level of a mono-pitch roof: -1.5% with a slope of 10% and -21% with a slope of 67.5% with the optimal building azimuth of 90°. However, its performance is slightly higher than the corresponding gabled roof (+2.5%, therefore, it could be a convenient alternative if optimally oriented and, above all, if the collectors are installed on the predominantly sunny part of the roof.

  17. Aboveground dendromass allometry of hybrid black poplars for energy crops

    Directory of Open Access Journals (Sweden)

    Tatiana Stankova

    2016-06-01

    Full Text Available Cultivation of energy crops is concerned with estimation of the total lignified biomass (dendromass production, which is based on the plantation density and individual plant dendromass. The main objective of this study was to investigate the allometry of aboveground leafless biomass of juvenile black poplar hybrids (Populus deltoides x P. nigra , traditionally used for timber and cellulose production, and to derive generic allometric models for dendromass prediction, relevant to energy crop cultivation in Bulgaria. The study material comprised a variety of growth sites, tree ages and clones, specific to poplar plantings in Bulgaria. We used three principal quantitative predictors: diameter at breast height, total tree height and mean stand (stock height. The models were not differentiated by clone, because the black poplar hybrids tested were not equally represented in the data, and the inclusion of tree age as a predictor variable seemed unreliable, because of the significant, up to 3 years, variation, which was possible within the narrow age range investigated. We defined the mean stand (stock height as a composite quantitative variable, which reflected the interaction between the time since planting (age, site quality and the intrinsic growth potential. Stepwise and backward multiple regression analyses were applied to these quantitative variables and their products and sets of adequacy and goodnessof-fit criteria were used to derive individual biomass models for stem and branches. Then we developed compatible additive systems of models for stem, branch and total lignified biomass in log-transformed form. Finally, the prediction data were back-transformed, applying correction for bias, and were cross-validated. Three systems of generic equations were derived to enable flexible model implementation. Equation system M1 proposes a stem biomass model based on tree and stand heights and stem diameter, and a model for

  18. Aboveground dendromass allometry of hybrid black poplars for energy crops

    Directory of Open Access Journals (Sweden)

    Tatiana Stankova

    2016-06-01

    Full Text Available Cultivation of energy crops is concerned with estimation of the total lignified biomass (dendromass production, which is based on the plantation density and individual plant dendromass. The main objective of this study was to investigate the allometry of aboveground leafless biomass of juvenile black poplar hybrids (Populus deltoides x P. nigra , traditionally used for timber and cellulose production, and to derive generic allometric models for dendromass prediction, relevant to energy crop cultivation in Bulgaria. The study material comprised a variety of growth sites, tree ages and clones, specific to poplar plantings in Bulgaria. We used three principal quantitative predictors: diameter at breast height, total tree height and mean stand (stock height. The models were not differentiated by clone, because the black poplar hybrids tested were not equally represented in the data, and the inclusion of tree age as a predictor variable seemed unreliable, because of the significant, up to 3 years, variation, which was possible within the narrow age range investigated. We defined the mean stand (stock height as a composite quantitative variable, which reflected the interaction between the time since planting (age, site quality and the intrinsic growth potential. Stepwise and backward multiple regression analyses were applied to these quantitative variables and their products and sets of adequacy and goodnessof-fit criteria were used to derive individual biomass models for stem and branches. Then we developed compatible additive systems of models for stem, branch and total lignified biomass in log-transformed form. Finally, the prediction data were back-transformed, applying correction for bias, and were cross-validated. Three systems of generic equations were derived to enable flexible model implementation. Equation system M1 proposes a stem biomass model based on tree and stand heights and stem diameter, and a model for

  19. Distribution of Aboveground Live Biomass in the Amazon Basin

    Science.gov (United States)

    Saatchi, S. S.; Houghton, R. A.; DosSantos Alvala, R. C.; Soares, J. V.; Yu, Y.

    2007-01-01

    The amount and spatial distribution of forest biomass in the Amazon basin is a major source of uncertainty in estimating the flux of carbon released from land-cover and land-use change. Direct measurements of aboveground live biomass (AGLB) are limited to small areas of forest inventory plots and site-specific allometric equations that cannot be readily generalized for the entire basin. Furthermore, there is no spaceborne remote sensing instrument that can measure tropical forest biomass directly. To determine the spatial distribution of forest biomass of the Amazon basin, we report a method based on remote sensing metrics representing various forest structural parameters and environmental variables, and more than 500 plot measurements of forest biomass distributed over the basin. A decision tree approach was used to develop the spatial distribution of AGLB for seven distinct biomass classes of lowland old-growth forests with more than 80% accuracy. AGLB for other vegetation types, such as the woody and herbaceous savanna and secondary forests, was directly estimated with a regression based on satellite data. Results show that AGLB is highest in Central Amazonia and in regions to the east and north, including the Guyanas. Biomass is generally above 300Mgha(sup 1) here except in areas of intense logging or open floodplains. In Western Amazonia, from the lowlands of Peru, Ecuador, and Colombia to the Andean mountains, biomass ranges from 150 to 300Mgha(sup 1). Most transitional and seasonal forests at the southern and northwestern edges of the basin have biomass ranging from 100 to 200Mgha(sup 1). The AGLB distribution has a significant correlation with the length of the dry season. We estimate that the total carbon in forest biomass of the Amazon basin, including the dead and below ground biomass, is 86 PgC with +/- 20% uncertainty.

  20. An Integrative Analysis of an Extensive Green Roof System: A Case Study of the Schleman Green Roof

    Science.gov (United States)

    Hoover, F.; Bowling, L. C.

    2013-12-01

    In urban environments where populations continue to rise, the need for affective stormwater management and runoff control methods is ever prevalent. Increased population growth and city expansion means greater impervious surfaces and higher rates of stormwater runoff. In well-established cities, this proves particularly difficult due to a constraining built environment and limited pervious spaces, even in cities as small as 40,000 residents. Work to reduce runoff in combined sewer systems (CSS) and municipal separated storm sewer systems (MS4) by use of best-management practices is one route currently under investigation. The Purdue University campus is making efforts to reduce their impact on the West Lafayette CSS and MS4. Green roofs are one management practice being used for runoff mitigation. Specifically, Schleman Hall, an administrative student affairs building, has a small green roof located on the second floor installed in 2008. In cooperation with Purdue Physical Facilities, monitoring and analysis for the Schleman extensive green roof at Purdue University was performed from June 2012 to December 2012. The objective was to determine the stormwater retention, output water quality and net present value for the 165 m2 roof. The results from the water balance analysis revealed retention rates on average of 58% of precipitation per rain event, where retention included soil moisture, evaporation and detention/depression storage. The water quality metrics tested were Nitrate-Nitrite (NO2-NO3), Orthophosphate (PO4), Ammonia-Ammonium ion (NH3-NH4), Sulfate (SO4), total suspended solids (TSS) and pH. The pollutant concentration and load results varied, but the pH levels from precipitation increased in all samples after passing through the substrate. SO4 and PO4 results yielded higher concentrations and loads in the green roof output than the control output and precipitation, while NO2-NO3 and NH3-NH4 yielded concentrations and loads that were reduced by the green

  1. 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.

  2. 屋顶绿化节能效益研究%Benefit of Energy Efficiency of Green Roofs

    Institute of Scientific and Technical Information of China (English)

    王丹; 管乃彦

    2015-01-01

    屋顶绿化是在改善城市区域的生态环境,美化城市景观,并且在有限的城市空间提高绿地率最有效的方式。屋顶绿化不但可以缓解城市热岛效应,还可以在节能和城市绿化方面发挥很好的作用。借助天津地区多层建筑的顶层房间为研究对象,综述多种不同的屋顶绿化构造及施工方式。通过 DesignBuilder 软件对非绿化与绿化屋顶房间在能耗方面进行分析模拟,采用碳税率法对屋顶绿地的固碳经济价值进行评估,将各项生态效益的经济价值进行计算,屋顶绿化对节能十分有效。%Roof greening is the most efficient way to improve the greening rate in limited urban space. It can not only alleviate the urban heat island effect, but also play a good role in energy conservation and urban greening. As the research object, the top floor of multi-story buildings in Tianjin combines with various structures of roof greening and ways of construction. The paper is to analyze and simulate differences of energy consumption between non-greening roof and greening roof by DesignBuilder software, and finally gets a conclusion that greening roof is available in energy efficiency.

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

    DEFF Research Database (Denmark)

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

    that there are no significant advantages of using white roofing felt instead of dark under Danish conditions in common buildings with active heating and passive cooling. Quite to the contrary it appears that dark roofing felts have significant advantages over white roofing felts. The results are discussed in the paper....... It should be mentioned that white roofing materials might be beneficial for poorly insulated buildings with high internal heat loads. In this case the white roofing might contribute to a reduced cooling. Also buildings with constant cooling demands or cold-storage plants etc. may benefit from white roofing...

  4. 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

  5. The Artistic Forms of Roof Moulds of Chinese Art Deco Style Residence%国内Art Deco风格住宅屋顶造型的艺术形式

    Institute of Scientific and Technical Information of China (English)

    陈昕楠; 陆影

    2015-01-01

    文章从影响Art Deco风格流变的几种思想着手,分析国内Art Deco风格住宅的屋顶造型演变过程,结合实例总结了3种常用的屋顶造型及其设计手法。%The evolution process of the roof shapes of domestic Art Deco residence is analysed by starting from several thoughts, which inlfuenced Art Deco. Combining with examples, three kinds of roof modeling are commonly used. And how to design these kinds of roof is analysed in the article.

  6. Roof heat loss detection using airborne thermal infrared imagery

    Science.gov (United States)

    Kern, K.; Bauer, C.; Sulzer, W.

    2012-12-01

    As part of the Austrian and European attempt to reduce energy consumption and greenhouse gas emissions, thermal rehabilitation and the improvement of the energy efficiency of buildings became an important topic in research as well as in building construction and refurbishment. Today, in-situ thermal infrared measurements are routinely used to determine energy loss through the building envelope. However, in-situ thermal surveys are expensive and time consuming, and in many cases the detection of the amount and location of waste heat leaving building through roofs is not possible with ground-based observations. For some years now, a new generation of high-resolution thermal infrared sensors makes it possible to survey heat-loss through roofs at a high level of detail and accuracy. However, to date, comparable studies have mainly been conducted on buildings with uniform roof covering and provided two-dimensional, qualitative information. This pilot study aims to survey the heat-loss through roofs of the buildings of the University of Graz (Austria) campus by using high-resolution airborne thermal infrared imagery (TABI 1800 - Thermal Airborne Broadband imager). TABI-1800 acquires data in a spectral range from 3.7 - 4.8 micron, a thermal resolution of 0.05 °C and a spatial resolution of 0.6 m. The remote sensing data is calibrated to different roof coverings (e.g. clay shingle, asphalt shingle, tin roof, glass) and combined with a roof surface model to determine the amount of waste heat leaving the building and to identify hot spots. The additional integration of information about the conditions underneath the roofs into the study allows a more detailed analysis of the upward heat flux and is a significant improvement of existing methods. The resulting data set provides useful information to the university facility service for infrastructure maintenance, especially in terms of attic and roof insulation improvements. Beyond that, the project is supposed to raise public

  7. Thermal Performance of Building Roof with Infrared Reflective Coatings

    Institute of Scientific and Technical Information of China (English)

    SHEN Hui; TAN Hong-wei; KATSUO MIKI; LIU Xiao-yu

    2009-01-01

    This paper investigated the applicability and effects of infrared reflective coating on energy con-sumption of factory building in hot summer and warm winter zone. It first resorted to theoretical calculation, which demonstrated the beneficial effects of infrared reflective coating on reducing building energy consumption. Then it analyzed a field measurement done on two identical rooms respectively with ordinary coated roof and in-frared reflective coated roof from November 2006 to October 2007, on a 24h basis. The measured data include exterior and interior roof surface temperature, indoor air temperature, and indoor globe temperature. The relat-ed weather data is from a weather station near the measured area. The continuous measurement has been accom-plished in southern China, and the measured data indicate that roof surface temperature and heat gain are signifi-cantly decreased in summer while slight negative effects in winter are induced by adopting infrared reflective coating. Thus it is simple and applicable to reduce building energy consumption in this area by applying infrared reflective coating. Regress equation between reduced roof thermal property, such as surface temperature and heat gain, and reduction in absorbed solar radiation shows their highly linear relationship. Based on the mea-sured data, it is estimated that the reduced power consumption is 3.45 kWh/m2·month in June.

  8. Effect of Composite Action on the Strength of Wood Roofs

    Directory of Open Access Journals (Sweden)

    Ivan A. Campos Varela

    2015-01-01

    Full Text Available Engineering certification for the installation of solar photovoltaic modules on wood roofs is often denied because existing wood roofs do not meet current building codes. Rather than requiring expensive structural retrofits, we desire to show that many roofs are actually sufficiently strong if the effect of composite action produced by joist-sheathing interaction is considered. In a series of laboratory experiments using a limited number of two-by-four wood joists with and without sheathing panels, conventionally sheathed stud-grade joists, surprisingly, exhibited between 18% and 63% higher nominal strength than similar bare joists. To explain this strength increase, a simple model was developed to predict the strengths of the nailed partially composite sections, but the model only justifies a 1.4% to 3.8% increase in bending strength of joists with an allowable bending strength of 1000 psi. More testing is indicated to resolve this discrepancy between laboratory results and analytical modeling results. In addition to elucidating nonlinear partial composite behavior of existing roof systems, this paper shows that, with minor changes in roof framing practices, strength increases of 70% or more are achievable, compared to the strengths of conventionally sheathed joists.

  9. A fuzzy approach to selecting roof supports in longwall mining

    Directory of Open Access Journals (Sweden)

    Yetkin, M. E.

    2016-05-01

    Full Text Available As a decision-making problem, selecting proper machines and equipment plays a key role for mining sites and companies. Many factors affect this decision, and values belonging to these factors can be expressed numerically and/or non-numerically. In order to make the most appropriate decision, engineers must carry out an evaluation process that comprises all criteria that might affect decision-making. To achieve this, multi-criteria decision-making tools are used. As a result of technological developments, coal outputs in longwall mining have risen tremendously over the last decades, and longwall mechanisation has become unavoidable. The significance of powered roof supports in particular increases day- by-day, since the rate of roof support has to be in accordance with the rate of face advance in longwalls. In this study, an integrated fuzzy analytic hierarchy process and fuzzy goal programming model is used to select the most suitable powered roof supports. The procedure is applied to a real-life underground coal mine that is operated using the longwall method. Seven alternative powered roof supports are compared with each other, taking a total of 24 decision criteria under four main topics into account. In conclusion, the most suitable roof supports for the mine under study are determined and recommended to the decision-makers of the system.

  10. A New Kind of Roof Greening System in China

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    With the wider use of green roofs, new technology and new materials are being applied to the field of building roof greening forbuildings. This paper introduces BRGS (built- up roof greening system), a new type of roof greening system that differs from roofgreening systems currently used in China in that it integrates a main and an auxiliary water storage capacity into the roof greeningsystem. Compared to other systems currently in use, BRGS offers a simpler, quicker, less labor intensive construction process;lighter floor load; and lower long term maintenance requirements and costs. It also makes full use of rainwater and snowmelt,which provides a significant amount of water to plants. This paper also introduces a planting experiment, the results of whichindicate that plants during their early stages of growth tolerate an alkaline environment, and that after a period of time, the pHvalue level of water stored in BRGS approaches 8.3, so we can conclude that BRGS is suitable for construction engineering.

  11. Numerical simulation of flows around long-span flat roof

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-ying; WU Yue; SHEN Shi-zhao

    2005-01-01

    Long-span roof with span larger than height always has a complicated three-dimensional curve. Wind pressure on the roof is often influenced not only by the atmospheric turbulence, but also by the "signature" turbulence provoked in the wind by the structure itself. So it is necessary to study characteristics of flows around the roof. In this paper, three-dimensional numerical simulation of wind-induced pressure has been performed on a long-span flat roof by means of Computational Fluid Dynamics (CFD) software--FLUENT. The flow characteristics are studied by considering some parameters, such as wind direction, span-height ratio, roof pitch, flow characteristics, roughness of terrain. The simulation is based upon the Reynolds-averaged equations, in which Reynolds stress equation model (RSM) and SIMPLE technology (Semi-Implicit Method for Pressure-Linked Equations) have been used. Compared with wind tunnel tests, the computational results have good agreement with the experimental data. It is proved that the results are creditable and the method is feasible.

  12. 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.

  13. The hydrological performance of a green roof test bed under UK climatic conditions

    Science.gov (United States)

    Stovin, Virginia; Vesuviano, Gianni; Kasmin, Hartini

    2012-01-01

    . Through a detailed examination of data from three contrasting events, it is argued that the inter-event processes are too complex to be captured by this type of modelling approach. Instead, an understanding of the hydrological processes affecting the flux of moisture into and out of the substrate is required to explain the observed runoff response. Locally-derived evapotranspiration rates and the roof's observed maximum retention capacity are utilised to provide pragmatic guidance on the retention performance to be expected in response to selected design events.

  14. 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

  15. 屋顶农场的意义及实践--以上海“天空菜园”系列为例%Research on the Significance and Practice of Roof Farm Taking Shanghai's "V-roof Rooftop Vegetable Garden" as an Example

    Institute of Scientific and Technical Information of China (English)

    朱胜萱; 高宁

    2013-01-01

      The roof is the negative space in Chinese city. The roof farm is a positive utilization of the roof space with economic, ecological and social benefits. Taking the"V-roof Rooftop Vegetable Garden" in Shanghai as an example, this paper introduces and analyses the spatial design, applicable technology and operation pattern of the roof farm. The authors found out that the roof farm is spatial y and technical y feasible, and the relevant urban management system is urgently needed during the operation process.%  屋顶是我国城市中的消极空间。屋顶农场是对建筑屋顶的一种积极利用方式,并具有经济效益、生态效益和社会效益。以上海“天空菜园”系列项目为研究对象,分别对屋顶农场的空间设计、适用技术以及运作模式进行介绍和分析:屋顶农场在空间及技术上是可行的,在运作过程中则急需城市管理制度的正面响应和引导。

  16. Understanding green roof spatial dynamics: results from a scale based hydrologic study and introduction of a low-cost method for wide-range monitoring

    Science.gov (United States)

    Hakimdavar, Raha; Culligan, Patricia J.; Guido, Aida

    2014-05-01

    Green roofs have the potential, if implemented on a wide scale and with proper foresight, to become an important supplement to traditional urban water management infrastructure, while also helping to change the face of cities from concrete draped, highly modified environments, to hybrid places where nature is more closely integrated into designs rather than pushed out of them. The ability of these systems to act as a decentralized rainwater handling network has been the topic of many recent studies. While these studies have attempted to quantify the hydrologic performance of green roofs, it's clear that they are dynamic systems whose responses are difficult to generalize. What also seems to be lacking from many studies is a discussion on the effects of green roof scale, spatial planning and configuration. This research aims to understand how rainfall characteristics and green roof scale impact its hydrologic performance. Three extensive green roof systems in New York City, with the same engineered components, age and regional climatic conditions, but different drainage areas, are analyzed. We find that rainfall volume and event duration are two of the parameters that most affect green roof performance, while rainfall intensity and antecedent dry weather period are less significant. We also find that green roof scale does in fact affect hydrologic performance, but mainly in reducing runoff peaks, with rainfall retention and lag time being much less affected by drainage area. We also introduce a low-cost monitoring method, termed the Soil Water Apportioning (SWA) method, which uses a water balance approach to analytically link precipitation to substrate moisture, and enable inference of green runoff and evapotranspiration from information on substrate moisture changes over time. Twelve months of in situ rainfall and soil moisture observations from three different green roof systems - extensive vegetated mat, semi-intensive vegetated mat, and semi-intensive tray - are

  17. Displacement, stress and seismicity in roadway roofs during mining-induced failure

    Energy Technology Data Exchange (ETDEWEB)

    Shen, B.; King, A.; Guo, H. [CSIRO Exploration & Mining, Kenmore, Qld. (Australia)

    2008-07-15

    Roof stability in gateroads is a long-standing issue in many of the underground mines in Australia that use longwall extraction methods, due primarily to a significant increase of vertical stresses ahead of the longwall face. Although numerous studies have been done in the past, the process of roof rock deformation and breakage prior to and during a roof failure in an actual mining environment is still being debated. This paper describes a new integrated roof monitoring system and the results from applying this system in an Australian underground coal mine. The system integrates displacement, stress and seismic monitoring. It has been applied to two roadways in an Australian underground coal mine during two field experiments. The key roof behaviour identified by the integrated monitoring package during the two field monitoring experiments is reported and discussed in this paper. The experiments were conducted in the 'tailgate' roadways that are adjacent to the caved zone, or 'goaf', of the previously mined panels. It was found in the experiments that, prior to roof falls, roof displacement accelerates whereas the horizontal stresses reduce. Seismic activity intensifies before major roof displacement or stress changes are evident, and subsides in the later stage of roof failure when large roof displacement is visible. The seismic resonance frequencies decrease during roof failure development. The field monitoring studies have also identified a number of quantitative and site-specific roof fall precursors potentially useful for roof fall prediction and prevention.

  18. Evaluation of aboveground and belowground biomass recovery in physically disturbed seagrass beds.

    Science.gov (United States)

    Di Carlo, Giuseppe; Kenworthy, W Judson

    2008-11-01

    Several studies addressed aboveground biomass recovery in tropical and subtropical seagrass systems following physical disturbance. However, there are few studies documenting belowground biomass recovery despite the important functional and ecological role of roots and rhizomes for seagrass ecosystems. In this study, we compared the recovery of biomass (g dry weight m(-2)) as well as the biomass recovery rates in ten severely disturbed multi-species seagrass meadows, after the sediments were excavated and the seagrasses removed. Three sites were located in the tropics (Puerto Rico) and seven in the subtropics (Florida Keys), and all were originally dominated by Thalassia testudinum. Total aboveground biomass reached reference values at four out of ten sites studied, two in the Florida Keys and two in Puerto Rico. Total belowground biomass was lower at the disturbed locations compared to the references at all sites, apart from two sites in the Florida Keys where the compensatory effect of opportunistic species (Syringodium filiforme and Halodule wrightii) was observed. The results revealed large variation among sites in aboveground and belowground biomass for all species, with higher aboveground recovery than belowground for T. testudinum. Recovery rates for T. testudinum were highly variable across sites, but a general trend of faster aboveground than belowground recovery was observed. Equal rates between aboveground and belowground biomass were found for opportunistic species at several sites in the Florida Keys. These results indicate the importance of belowground biomass when assessing seagrass recovery and suggest that the appropriate metric to assess seagrass recovery should address belowground biomass as well as aboveground biomass in order to evaluate the full recovery of ecological services and functions performed by seagrasses. We point out regional differences in species composition and species shifts following severe disturbance events and discuss

  19. 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.

  20. Requirements of inverted roofs with a drainage layer

    DEFF Research Database (Denmark)

    Leimer, Hans-Peter; Rode, Carsten; Künzel, Hartwig

    2005-01-01

    flowing between the insulation and the waterproofing membrane. It is possible to calculate the extra heat loss of inverted roofs caused by rain water below the heat insulation. The extra heat loss depends on the average rainfall and on which fraction of the rain water that will drain between...... the waterproofing membrane and the thermal insulation. This paper explains the application of the standard for areas of Europe. Furthermore, some constructions are proposed, which have such small extra heat losses caused by rain water that they may be disregarded in the calculation.......This contribution illustrates the application of the standard EN ISO 6946 regarding the heat loss of an inverted roof for different regions of Europe. An addendum to the standard (EN ISO 6946:1996/A1, 2003) introduces a correction to the thermal transmittance of inverted roofs due to rain water...