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1

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

Microsoft Academic Search

This paper shows the results of the second part of an experimental study aimed at analysing the effects of roof tile permeability on the thermal performances of ventilation ducts. Ventilation ducts under the layer of tiles are typically used in south European countries to limit the energy load during the summer period. The results of the first part of the

M. D’Orazio; C. Di Perna; P. Principi; A. Stazi

2008-01-01

2

Thermal performance of PCM thermal storage unit for a roof integrated solar heating system  

Microsoft Academic Search

The thermal performance of a phase change thermal storage unit is analysed and discussed. The storage unit is a component of a roof integrated solar heating system being developed for space heating of a home. The unit consists of several layers of phase change material (PCM) slabs with a melting temperature of 29°C. Warm air delivered by a roof integrated

W. Saman; F. Bruno; E. Halawa

2005-01-01

3

Weather effect on thermal and energy performance of an extensive tropical green roof  

Microsoft Academic Search

This study investigated the weather effect on thermal performance of a retrofitted extensive green roof on a railway station in humid-subtropical Hong Kong. Absolute and relative (reduction magnitude) ambient and surface temperatures recorded for two years were compared amongst antecedent bare roof, green roof, and control bare roof. The impacts of solar radiation, relative humidity, soil moisture and wind speed

C. Y. Jim; Lilliana L. H. Peng

4

Thermal and electrical performance of a solar multifunctional roof  

Microsoft Academic Search

In a collaborative project between the Lombardy Region and Politecnico di Milano, a solar roof has been installed during the functional and technical refurbishment of the main building of the Centre of Professional Training (CFPA) of Casargo, Lecco. The refurbishment program of the CFP is focused on the technical systems for thermal energy supply for various building applications, e.g. sanitary

N. Aste; R. S. Adhikari; G. Chiesa; L. C. Tagliabue

2007-01-01

5

Comparison of the dynamic thermal performance of insulated roof systems  

SciTech Connect

The Large Scale Climate Simulator at the DOE-sponsored Roof Research Center has been used to provide data for a comparison of the thermal resistance of three common roof insulations over an extended range of temperatures using two different techniques; one steady state and the other transient. The insulations are fiberglass, expanded polystyrene (EPS), and phenolic foam board. R-values are determined for temperatures ranging from 10/degree/F to 130/degree/F. Results from the two techniques are in agreement with one another and both are within 5 percent of reference values for the insulations. The testing illustrates the flexibility of the Large Scale Climate Simulator. 8 refs., 11 figs., 1 tab.

Courville, G.E.; Shipp, P.H.; Petrie, T.W.; Childs, P.W.

1989-01-01

6

Thermal performance analysis and economic evaluation of roof-integrated solar concrete collector  

Microsoft Academic Search

This paper examines the thermal performance of a roof-integrated solar concrete collector for reducing heat gain to a house and providing domestic hot water. The solar concrete collector is made of PVC pipes embedded in deck slab or concrete roof. No glazing on the top of the solar concrete collector or insulation at the back has been used as in

Rangsit Sarachitti; Chaicharn Chotetanorm; Charoenporn Lertsatitthanakorn; Montana Rungsiyopas

2011-01-01

7

Thermal behaviour of vented roofs  

Microsoft Academic Search

Purpose – The purpose of this paper is to present the results of an experimental study aimed at analysing the effect of the roof tile air permeability on the thermal performances of ventilation ducts in the roof. The main reason underlying this study is the fact that the theoretical reference assumed for the manufacture and sizing of ventilation ducts (the

M. DOrazio; C. Di Perna; F. Stazi

2009-01-01

8

Performance evaluation of a building integrated semitransparent photovoltaic thermal system for roof and facade  

Microsoft Academic Search

In this paper, analytical expressions have been derived for room air temperature of building integrated semitransparent photovoltaic thermal (BISPVT) and building integrated opaque photovoltaic thermal (BIOPVT) systems each integrated to the roof of a room with and without air duct. Comparative studies have also been carried out between BISPVT and BIOPVT system each integrated to the façade and roof of

Kanchan Vats; G. N. Tiwari

9

Performance evaluation of green roof and shading for thermal protection of buildings  

Microsoft Academic Search

The present paper describes a mathematical model for evaluating cooling potential of green roof and solar thermal shading in buildings. A control volume approach based on finite difference methods is used to analyze the components of green roof, viz. green canopy, soil and support layer. Further, these individual decoupled models are integrated using Newton's iterative algorithm until the convergence for

Rakesh Kumar; S. C. Kaushik

2005-01-01

10

Green roofs are not created equal: the hydrologic and thermal performance of six different extensive green roofs and reflective and non-reflective roofs in a sub-tropical climate  

Microsoft Academic Search

Green roofs have the potential to retain stormwater on the roof surface and lower the thermal loading on buildings. Because\\u000a of this, the greatest environmental benefits from green roofs might be achieved in subtropical climates characterized by high\\u000a temperatures and intense rain events. There is, however, little research to support this. In a replicated study in Texas,\\u000a we compared the

Mark T. Simmons; Brian Gardiner; Steve Windhager; Jeannine Tinsley

2008-01-01

11

Analysis of the green roof thermal properties and investigation of its energy performance  

Microsoft Academic Search

The advantages of the planned roofs are undoubtedly numerous from both the ecological and the social point of view. They act positively upon the climate of the city and its region, as well as upon the interior climate of the buildings beneath them. They give protection from the solar radiation, which is the main factor in passive cooling. By reducing

A. Niachou; K Papakonstantinou; M Santamouris; A Tsangrassoulis; G Mihalakakou

2001-01-01

12

Roof–envelope ratio impact on green roof energy performance  

Microsoft Academic Search

This paper addresses the impact of roof-to-envelope ratio on overall energy savings of a green roof design over conventional\\u000a roof designs. Simulations were performed using a modified version of the Environmental System Performance program simulator,\\u000a developed at the University of Strathclyde. The modified design employed a model developed by Columbia University and the\\u000a Goddard Institute of Space Science which models

Ryan Martens; Brad Bass; Susana Saiz Alcazar

2008-01-01

13

Effect of vegetation biomass structure on thermal performance of tropical green roof  

Microsoft Academic Search

The passive cooling effect of green roofs in humid, tropical Hong Kong was investigated with reference to three vegetated\\u000a plots, grass, groundcover herb, and shrub, with contrasting growth form and biomass structure and a bare control plot. Temperature\\u000a was monitored at 15-min intervals for a year at seven levels: high (H) at 200 cm, middle (M) at 60 cm, low (L) at

C. Y. Jim

14

Influence of the thermal trap material on the performance of a roof as an inexpensive collector\\/storage system  

Microsoft Academic Search

An analysis of the behaviour of a network of pipes buried in a flat roof, with a thermal trap material at its top, is presented. An analytical solution for the heat flux entering a room and the heat retrieved for two modes of operation--(a) constant flow rate and (b) constant collection temperature, as functions of meteorological, as well as design,

G. N. Tiwari

1985-01-01

15

Performance of antisolar insulated roof system  

Microsoft Academic Search

Rooms with concrete slab roofs directly exposed to the sun become unbearably hot during summer and very cold during winter. Huge amounts of energy are required to keep them comfortable. Application of thermal insulation on roofs significantly reduces energy required for heating and cooling. The effectiveness of roof insulations may be further enhanced if a layer of antisolar coating is

Irshad Ahmad

2010-01-01

16

The contribution of a planted roof to the thermal protection of buildings in Greece  

Microsoft Academic Search

Planted roofs contribute positively to the improvement of the thermal performance of a building. They block solar radiation, and reduce daily temperature variations and thermal ranges between winter and summer. In this paper, a calculation has been done, using a stationary method, in order to determine the thermal behaviour of the planted roof and the way it influences the thermal

Ekaterini Eumorfopoulou; Dimitris Aravantinos

1998-01-01

17

The thermal performance of a Roof-Pond integrated to a building for heating during Cold-Winter Desert climate conditions in Saudi Arabia  

Microsoft Academic Search

This study reports an experiment to investigate the feasibility of a passive heating roof-pond system on an existing room in the cold winter conditions of Riyadh, Saudi Arabia. Statistical analyses of data recorded during the winter season of 1996–97, are carried out to evaluate the thermal peformance of the proposed system. Total effective heating and the heating power of the

N. Al-Hemiddi

1999-01-01

18

Performance and costs of a roof-sized PV\\/thermal array combined with a ground coupled heat pump  

Microsoft Academic Search

A photovoltaic\\/thermal (PVT) panel is a combination of photovoltaic cells with a solar thermal collector, generating solar electricity and solar heat simultaneously. Hence, PVT panels are an alternative for a combination of separate PV panels and solar thermal collectors. A promising system concept, consisting of 25m2 of PVT panels and a ground coupled heat pump, has been simulated in TRNSYS.

M. Bakker; H. A. Zondag; M. J. Elswijk; K. J. Strootman; M. J. M. Jong

2005-01-01

19

Compensating the thermal expansion of refractories in a suspended roof  

Microsoft Academic Search

In this method of roof suspension the constructional stresses in the arch are significantly reduced but the problem of the stresses due to thermal expansion has not yet been resolved. The known methods of calculating thermal expansion fail to take account of the leakage between the bricks and of the influence of the steel inserts on the density of the

V. A. Kulichenko; M. A. Akbiev; V. V. Ivankov; V. T. Selyanko; I. P. Gerasimenko

1975-01-01

20

Performance of trombe walls and roof pond systems  

Microsoft Academic Search

This paper describes an analysis of the periodic heat transfer through thermal storage walls and roof pond systems subjected to periodic solar radiation and atmospheric air on one side and in contact with room air at constant temperature (corresponding to air-conditioned rooms) on the other. A one-dimensional heat conduction equation for temperature distribution in the walls and roof has been

M. S. Sodha; S. C. Kaushik; J. K. Nayak

1981-01-01

21

Experimental investigation and numerical simulation analysis on the thermal performance of a building roof incorporating phase change material (PCM) for thermal management  

Microsoft Academic Search

Thermal storage plays a major role in a wide variety of industrial, commercial and residential application when there is a mismatch between the supply and demand of energy. Latent heat storage in a phase change material (PCM) is very attractive, because of its high-energy storage density and its isothermal behavior during the phase change process. Several promising developments are taking

A. Pasupathy; L. Athanasius; R. Velraj; R. V. Seeniraj

2008-01-01

22

The effect of a reflective underlay on the global thermal behaviour of pitched roofs  

Microsoft Academic Search

The influence of the emissivity of a roof underlay on the global thermal behaviour of sloped roofs is investigated. Five well-insulated pitched roofs have been constructed in a test building. The five roofs have a south-west and north-east-oriented pitch and differ in long wave emissivity of the underlay. All roofs are equipped with thermocouples and heat fluxes sensors to evaluate

S. Roels; M. Deurinck

2011-01-01

23

Thermal stress state of an underground powerhouse roof during construction and operation  

Microsoft Academic Search

Conclusions 1.Forced ventilation accompanying the driving of underground workings leads to substantial temperature fluctuations of the roof surface and to the occurrence of thermal compressive stresses in the roof of the powerhouse. The maximum compressive stresses in the roof are observed at those times of the construction period when the values of the temperature gradients in the radial direction and

G. L. Khesin; G. S. Vardanyan; V. N. Savot'yanov; A. S. Isaikin; L. Yu. Frishter; O. A. Kogodovskii

1988-01-01

24

High Performance Roofing Systems (Conference, 1 March 1984).  

National Technical Information Service (NTIS)

Contents: Flat roofing; Improved traditional roofing - polymer modified bitumens with and without polymeric fibre reinforcement; Rubber and plastic membrane systems; Liquid applied roofing systems; Coated fabric roofs; The structural use of coated fabrics...

1984-01-01

25

Protection of Foam Plastic Thermal Insulation in Low Sloped Roofing Systems  

Microsoft Academic Search

Foam plastic thermal insulations have substantially replaced traditional insulations in low sloped roofing systems in North America. Foam plastic thermal insulations used in low sloped roofs are low density (typically 16–48 kg\\/m3) materials with low permeability to air and water vapour. In many roofs these materials have been directly substituted for traditional (wood and glass fibre) insulations without due attention

Robert J. Booth; Clinton Derushie; Karen Liu

2002-01-01

26

Long-term performance of high-albedo roof coatings  

Microsoft Academic Search

ooling energy savings of 10 to 70% have been achieved by applying high-albedo coatings to residential buildings in California and Florida. Since dirt accumulation can alter the performance of high-albedo roofs as an energy efficiency measure, we examined some high-albedo coatings at various stages of exposure to determine the magnitude of this effect. We conclude that most of the albedo

Sarah E. Bretz; Hashem Akbari

1997-01-01

27

Design, effectiveness, and construction of passive-thermal-control roofing shingles. Technical final report  

SciTech Connect

The concept of a passive thermal control roofing shingle, which is a shingle that reflects the summer sun and absorbs the winter sun, is discussed. Such a shingle will reduce summer cooling and winter heating costs and conserve electricity and natural gas or heating oil. Design calculations indicate that it is possible to design shingles for particular latitudes and styles of roof which absorb nearly all of the winter solar energy and reflect nearly all of the summer solar energy. Calculations of the energy savings and cost effectiveness of the passive thermal control roofing shingle indicate that it is most cost effective on all south facing pitched roofs regardless of heating fuel type, and on flat or east or west facing roofs that are heated with costly fuels such as electricity or heating oil. The shingle is most effective on poorly insulated structures. If the cost of the shingle is about one dollar per square foot it will be cost effective in these applications. Additional calculations demonstrate the feasibility of using the passive thermal control roofing shingle in conjunction with a heat pump to pump heat absorbed by the shingle into a well insulated structure. Construction of a variety of models of the passive thermal control roofing shingle illustrate numerous alternate methods of manufacture. A profile extruded, plastic, glazed shingle appears to be the most promising approach. Additionally, extruded plastic reflector assemblies of various kinds could be added to existing shingled roofs. Use of a glazed shingle can increase the effectiveness of the passive thermal control roofing shingle by reducing convective heat losses.

Wolf, L. Jr.

1982-09-01

28

Equilibrium thermal characteristics of a building integrated photovoltaic tiled roof  

SciTech Connect

Photovoltaic (PV) modules attain high temperatures when exposed to a combination of high radiation levels and elevated ambient temperatures. The temperature rise can be particularly problematic for fully building integrated PV (BIPV) roof tile systems if back ventilation is restricted. PV laminates could suffer yield degradation and accelerated aging in these conditions. This paper presents a laboratory based experimental investigation undertaken to determine the potential for high temperature operation in such a BIPV installation. This is achieved by ascertaining the dependence of the PV roof tile temperature on incident radiation and ambient temperature. A theory based correction was developed to account for the unrealistic sky temperature of the solar simulator used in the experiments. The particular PV roof tiles used are warranted up to an operational temperature of 85 C, anything above this temperature will void the warranty because of potential damage to the integrity of the encapsulation. As a guide for installers, a map of southern Europe has been generated indicating locations where excessive module temperatures might be expected and thus where installation is inadvisable. (author)

Mei, L.; Gottschalg, R.; Loveday, D.L. [Centre for Renewable Energy Systems Technology (CREST), Department of Electronic and Electrical Engineering, Loughborough University, Loughborough, Leicestershire, LE11 3TU (United Kingdom); Infield, D.G. [Institute of Energy and Environment, Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, G1 1XW (United Kingdom); Davies, D.; Berry, M. [Solarcentury, 91-94 Lower Marsh Waterloo, London, SE1 7AB (United Kingdom)

2009-10-15

29

The Influence of Low-Permeance Vapor Barriers on Roof and Wall Performance  

Microsoft Academic Search

Low-permeance vapor barriers are widely used on the interior of wall and roof systems in large parts of North America. Many codes and standards imply or even state that low-permeance vapor barriers should be used in all cold regions as well as many moderate climate zones. The influence of vapor barriers on the hygrothermal performance of wall and roof systems

J. F. Straube

30

Thermal Comparison of Reflective and Non-Reflective Roofs with Thin-Film Solar Panels  

Microsoft Academic Search

The present paper illustrates an experimental and comparative thermal analysis of reflective (white) and non-reflective (black) roofing membranes paired with thin-film solar photovoltaic panels. Tests were carried out on two different membranes, thermoplastic olefin (TPO), and ethylene propylene diene monomer (EPDM). Solar irradiance along with temperature readings on the surface, between the panel and membrane, and below the membrane were

Grant Irvine; Serdar Celik

2012-01-01

31

Heat Transfer in a Wet Porous Thermal Insulation in a Flat Roof  

Microsoft Academic Search

Glass fiber insulation specimens with moisture contents ranging from 0 to 15 % by volume were placed on the roof of an outdoor test facility. Heat flow measurements were made, using heat flux transducers at all seasons of the year. Outdoor tempera tures ranged from about -40° to +35°C.Thermal conductances for the wet insulations increase sharply in warm weather when

C. P. Hedlin

1988-01-01

32

Performance of natural fibre reinforced mortar roofing tiles  

Microsoft Academic Search

Interest in natural fibres as reinforcement in developing countries arose (when the use of steel and glass fibres in the industrialized\\u000a countries was being researched and developed in the late 1960s) mostly because of their lower cost and better availability\\u000a in the developing world. The use of natural fibres as reinforcement for mortar to be used mainly for roofing has

Zawde Berhane

1994-01-01

33

The experimentally measured performance of a linear roof aperture daylighting system  

Microsoft Academic Search

Illumination and solar radiation measurements have been made on a scale-model building containing sloped, south-facing, double-pane roof glazing. To control glare and properly disperse the beam sunlight over the work plane, a good diffusing glazing is used for the inside pane of the roof aperture. Measurements have been made in order to investigate the performance of this daylighting system under

F. Bauman; B. Andersson; T. C. Howard; J. Thornton

1986-01-01

34

Green roof energy and water related performance in the Mediterranean climate  

Microsoft Academic Search

Performance of vegetated roofs are investigated in terms of their expected benefits for the building and the urban environment, due to their recognised energy and water management potential scores. A review of related worldwide experiences is reported for comparison purposes. The investigation is here performed within the specific climatic context of the Mediterranean region. Full-scale experimental results are provided from

R. Fioretti; A. Palla; L. G. Lanza; P. Principi

2010-01-01

35

Experimental and modelling performances of a roof-integrated solar drying system for drying herbs and spices  

Microsoft Academic Search

This paper presents experimental performance of solar drying of rosella flower and chili using roof-integrated solar dryer and also presents modelling of the roof-integrated solar dryer for drying of chili. Field-level tests for deep bed drying of rosella flower and chili demonstrated that drying in the roof-integrated solar dryer results in significant reduction in drying time compared to the traditional

S. Janjai; N. Srisittipokakun; B. K. Bala

2008-01-01

36

Self drying roofs: What! No dripping!  

SciTech Connect

Many roofs are replaced because water accumulates in portions of the roofing system.These accumulations can cause dripping, accelerated membrane failure, poor thermal performance, the threat of structural decay, and the depreciation of building assets. Traditionally, the roofing industry has been concerned with controlling the inflow of water into the roof. An example of this strategy would be the development of a more reliable membrane. However, roof membranes inevitably leak. For this reason, the roof design strategy of the future must be concerned with controlling water outflow. The requirements of this type of roof system are described. Under normal operating conditions (no leaks), the total moisture content of a self-drying roof system shall not increase with time and condensation shall not occur under the membrane during winter uptake. Moisture vapor movement by convection must be eliminated and the flow of water by gravity through imperfections in the roof system must be controlled. After a leak has occurred, no condensation on the upper surface of the deck shall be tolerated and the water introduced by the leak must be dissipated to the building interior in a minimum amount of time. Finite difference computer modeling is used to demonstrate the effectiveness of the design. The impact of deck and insulation permeance, climate, leaks, and wintertime water uptake are simulated. A database of simulations is qualitatively described; this database will be used in future work to produce a simplified means of assessing the design parameters of a self-drying roof system.

Desjarlais, A.

1995-12-31

37

Thermal Environments and Performance.  

National Technical Information Service (NTIS)

Although several reviews of thermal influences on performance have appeared during the past decade, none have succeeded in synthesizing the various experimental results. In the meantime, new evidence has been presented from several studies, particularly t...

A. Auliciems

1973-01-01

38

Three Dimensional Numerical Simulation of Air Flow over Domed Roofs  

NASA Astrophysics Data System (ADS)

Using domed roofs to reduce building solar load in hot arid area is one of Iranian mechanical engineering masterworks. The first application of these roofs was to cover large buildings such as mosques, shrines, etc. However their thermal performance made them to be employed in other buildings like bazaars. The aim of this study was to determine the air pressure and velocity distribution over domed roofs, by employing numerical methods. The results of this study will be used as the first step for thermal performance evaluation of domed roofs.

Faghih, A. K.; Bahadori, M. N.

2007-09-01

39

Advanced Energy Efficient Roof System  

SciTech Connect

Energy consumption in buildings represents 40 percent of primary U.S. energy consumption, split almost equally between residential (22%) and commercial (18%) buildings.1 Space heating (31%) and cooling (12%) account for approximately 9 quadrillion Btu. Improvements in the building envelope can have a significant impact on reducing energy consumption. Thermal losses (or gains) from the roof make up 14 percent of the building component energy load. Infiltration through the building envelope, including the roof, accounts for an additional 28 percent of the heating loads and 16 percent of the cooling loads. These figures provide a strong incentive to develop and implement more energy efficient roof systems. The roof is perhaps the most challenging component of the building envelope to change for many reasons. The engineered roof truss, which has been around since 1956, is relatively low cost and is the industry standard. The roof has multiple functions. A typical wood frame home lasts a long time. Building codes vary across the country. Customer and trade acceptance of new building products and materials may impede market penetration. The energy savings of a new roof system must be balanced with other requirements such as first and life-cycle costs, durability, appearance, and ease of construction. Conventional residential roof construction utilizes closely spaced roof trusses supporting a layer of sheathing and roofing materials. Gypsum board is typically attached to the lower chord of the trusses forming the finished ceiling for the occupied space. Often in warmer climates, the HVAC system and ducts are placed in the unconditioned and otherwise unusable attic. High temperature differentials and leaky ducts result in thermal losses. Penetrations through the ceilings are notoriously difficult to seal and lead to moisture and air infiltration. These issues all contribute to greater energy use and have led builders to consider construction of a conditioned attic. The 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 the study. The market potential is enhanced through construction activity levels in target marke

Jane Davidson

2008-09-30

40

SWITCH in Birmingham, UK: experimental investigation of the ecological and hydrological performance of extensive green roofs  

Microsoft Academic Search

This paper summarises research based in the city of Birmingham, UK, into the ecological and hydrological performance of extensive\\u000a green roofs designed to act as mitigation for the loss of brownfield habitat. It focuses particularly on possible trade-offs\\u000a between design elements that maximise biodiversity potential, and design elements that maximise rainfall run-off management\\u000a potential.

Adam J. Bates; Rae Mackay; Richard B. Greswell; Jon P. Sadler

2009-01-01

41

BENEFITS AND POTENTIAL APPLICATIONS OF GREEN ROOF SYSTEMS IN HONG KONG  

Microsoft Academic Search

Green roof systems are living vegetation installed on the roofs and could contribute positively to the mitigation of urban heat island and enhancement of building thermal and environmental performance. Research study has been carried out to investigate the green roof technology and research in the world, with the aim to develop practical information for its applications in Hong Kong and

SAM C. M. HUI

42

Standards of Performance for New Stationary Sources Asphalt Processing and Asphalt Roofing Manufacture: Enforcement Aspects Statement and Reports Impact Analysis.  

National Technical Information Service (NTIS)

The recommended standards of performance will limit the emission of particulate matter from asphalt roofing manufacturing plants and from blowing stills and asphalt storage tanks at oil refineries and asphalt processing plants. These standards include bot...

1980-01-01

43

DYNAMIC THERMALLY-DISCONNECTED BUILDING ENVELOPES A NEW PARADIGM FOR WALLS AND ROOFS IN LOW ENERGY BUILDINGS  

SciTech Connect

This paper describes numerical and experimental analysis of a novel design concept. Traditionally the thermal design of building envelope assemblies is based on a static energy flow. However, building envelopes are subject to varying environmental conditions. This mismatch between the steady-state principles used in the design of roofs and walls and their dynamic operation results in relatively low thermal efficiency. Design work in support of the development of zero energy houses showed that conventional insulations may not be the most cost effective energy solution. Testing conducted on several strategies to thermally-disconnect wall and roof components showed 70% to 90% reductions in peak hour loads as compared to conventional building practice.

Miller, William A [ORNL; Kosny, Jan [ORNL; Zaltash, Abdolreza [ORNL

2010-01-01

44

Roof System EPDM Shrinkage.  

ERIC Educational Resources Information Center

Looks at Ethylene Propylene Diene Terpolymer rubber roof membranes and the potential problems associated with this material's shrinkage. Discusses how long such a roof should perform and issues affecting repair or replacement. Recommends that a building's function be considered in any roofing decision. (RJM)

Betker, Edward

1998-01-01

45

Predicting the Performance of Small Wind Turbines in the RoofTop Urban Environment  

Microsoft Academic Search

This paper summarises the results of computational fluid dynamics (CFD) and semi-empirical modelling to predict wind resource and expected output of small wind turbines mounted on building roofs within the urban environment. A number of configurations are considered including; different roof pitches, flat topped roofs, houses laid out in different street configurations and houses on slopes. An example calculation is

David Infield; Mark Harding

46

Long-term hygrothermal performance of white and black roofs in North American climates  

Microsoft Academic Search

When solar radiation hits a roof surface, a part of solar energy is reflected and part is absorbed. The absorbed part of solar energy results in an increase of the surface temperature of the roof. Cool reflective (white) roofs use bright surfaces to reflect a significant portion of the incident short-wave solar radiation, which lowers the surface temperature compared to

Hamed H. Saber; Michael C. Swinton; Peter Kalinger; Ralph M. Paroli

47

Green roof performance towards management of runoff water quantity and quality: A review  

Microsoft Academic Search

This review paper addresses the role of green roofs in urban drainage considering both management of water quantity and quality. Results from investigation of full scale installations as well as from laboratory models are reviewed. The following factors affecting runoff dynamics from green roofs are discussed: type of green roof and its geometrical properties (slope); soil moisture characteristics; season, weather

Justyna Czemiel Berndtsson

2010-01-01

48

Three Dimensional Numerical Simulation of Air Flow over Domed Roofs  

Microsoft Academic Search

Using domed roofs to reduce building solar load in hot arid area is one of Iranian mechanical engineering masterworks. The first application of these roofs was to cover large buildings such as mosques, shrines, etc. However their thermal performance made them to be employed in other buildings like bazaars. The aim of this study was to determine the air pressure

A. K. Faghih; M. N. Bahadori

2007-01-01

49

PERFORMANCE EVALUATION OF A SUSTAINABLE AND ENERGY EFFICIENT RE-ROOFING TECHNOLOGY USING FIELD-TEST DATA  

SciTech Connect

Three test attics were constructed to evaluate a new sustainable method of re-roofing utilizing photo-voltaic (PV) laminates, metal roofing panels, and PCM heat sink in the Envelope Systems Research Apparatus (ESRA) facility in the ORNL campus. Figure 1 is a picture of the three attic roofs located adjacent to each other. The leftmost roof is the conventional shingle roof, followed by the metal panel roof incorporating the cool-roof coating, and third from left is the roof with the PCM. On the PCM roof, the PV panels are seen as well; they're labelled from left-to-right as panels 5, 6 and 7. The metal panel roof consists of three metal panels with the cool-roof coating; in further discussion this is referred to as the infrared reflective (IRR) metal roof. The IRR metal panels reflect the incoming solar radiation and then quickly re-emit the remaining absorbed portion, thereby reducing the solar heat gain of the attic. Surface reflectance of the panels were measured using a Solar Spectrum Reflectometer. In the 0.35-2.0 {mu}m wavelength interval, which accounts for more than 94% of the solar energy, the IRR panels have an average reflectance of 0.303. In the infrared portion of the spectrum, the IRR panel reflectance is 0.633. The PCM roof consists of a layer of macro-encapsulated bio-based PCM at the bottom, followed by a 2-cm thick layer of dense fiberglass insulation with a reflective surface on top, and metal panels with pre-installed PV laminates on top. The PCM has a melting point of 29 C (84.2 F) and total enthalpy between 180 and 190 J/g. The PCM was macro-packaged in between two layers of heavy-duty plastic foil forming arrays of PCM cells. Two air cavities, between PCM cells and above the fiberglass insulation, helped the over-the-deck natural air ventilation. It is anticipated that during summer, this extra ventilation will help in reducing the attic-generated cooling loads. The extra ventilation, in conjunction with the PCM heat sink, are used to minimize thermal stresses due to the PV laminates on sunny days. In PV laminates sunlight is converted into electricity and heat simultaneous. In case of building integrated applications, a relatively high solar absorption of amorphous silicon laminates can be utilized during the winter for solar heating purposes with PCM providing necessary heat storage capacity. However, PV laminates may also generate increased building cooling loads during the summer months. Therefore, in this project, the PCM heat sink was to minimize summer heat gains as well. The PCM-fibreglass-PV assembly and the IRR metal panels are capable of being installed directly on top of existing shingle roofs during re-roofing, precluding the need for recycling or disposal of waste materials. The PV laminates installed on the PCM attic are PVL-144 models from Uni-Solar. Each laminate contains 22 triple junction amorphous silicon solar cells connected in series. The silicon cells are of dimensions 356 mm x 239 mm (14-in. x 9.4-in.). The PVL-144 laminate is encapsulated in durable ETFE (poly-ethylene-co-tetrafluoroethylene) high light-transmissive polymer. Table 1 lists the power, voltage and current ratings of the PVL-144 panel.

Biswas, Kaushik [ORNL; Miller, William A [ORNL; Childs, Phillip W [ORNL; Kosny, Jan [ORNL; Kriner, Scott [Metal Construction Association, Glenview, IL

2011-01-01

50

Two-Year Wisconsin Thermal Loads for Roof Assemblies and Wood, Wood Plastic Composite, and Fiberglass Shingles.  

National Technical Information Service (NTIS)

Temperature histories for various types of roof shingles, wood roof sheathing, roof rafters, and non-ventilated attics are being monitored in outdoor attic structures using simulated North American light-framed construction. This report presents 2-year da...

J. E. Winandy M. Grambsch C. A. Hatfield

2005-01-01

51

Effectiveness of Cool Roof Coatings with Ceramic Particles  

SciTech Connect

Liquid applied coatings promoted as cool roof coatings, including several with ceramic particles, were tested at Oak Ridge National Laboratory (ORNL), Oak Ridge, Tenn., for the purpose of quantifying their thermal performances. Solar reflectance measurements were made for new samples and aged samples using a portable reflectometer (ASTM C1549, Standard Test Method for Determination of Solar Reflectance Near Ambient Temperature Using a Portable Solar Reflectometer) and for new samples using the integrating spheres method (ASTM E903, Standard Test Method for Solar Absorptance, Reflectance, and Transmittance of Materials Using Integrating Spheres). Thermal emittance was measured for the new samples using a portable emissometer (ASTM C1371, Standard Test Method for Determination of Emittance of Materials Near Room 1 Proceedings of the 2011 International Roofing Symposium Temperature Using Portable Emissometers). Thermal conductivity of the coatings was measured using a FOX 304 heat flow meter (ASTM C518, Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus). The surface properties of the cool roof coatings had higher solar reflectance than the reference black and white material, but there were no significant differences among coatings with and without ceramics. The coatings were applied to EPDM (ethylene propylene diene monomer) membranes and installed on the Roof Thermal Research Apparatus (RTRA), an instrumented facility at ORNL for testing roofs. Roof temperatures and heat flux through the roof were obtained for a year of exposure in east Tennessee. The field tests showed significant reduction in cooling required compared with the black reference roof (~80 percent) and a modest reduction in cooling compared with the white reference roof (~33 percent). The coating material with the highest solar reflectivity (no ceramic particles) demonstrated the best overall thermal performance (combination of reducing the cooling load cost and not incurring a large heating penalty cost) and suggests solar reflectivity is the significant characteristic for selecting cool roof coatings.

Brehob, Ellen G [ORNL; Desjarlais, Andre Omer [ORNL; Atchley, Jerald Allen [ORNL

2011-01-01

52

Performance of powder-filled evacuated panel insulation in a manufactured home roof cavity: Tests in the Large Scale Climate Simulator  

SciTech Connect

A full-scale section of half the top of a single-wide manufactured home has been studied in the Large Scale Climate Simulator (LSCS) at the Oak Ridge National Laboratory. A small roof cavity with little room for insulation at the eaves is often the case with single-wide units and limits practical ways to improve thermal performance. The purpose of the current tests was to obtain steady-state performance data for the roof cavity of the manufactured home test section when the roof cavity was insulated with fiberglass batts, blown-in rock wool insulation or combinations of these insulations and powder-filled evacuated panel (PEP) insulation. Four insulation configurations were tested: (A) a configuration with two layers of nominal R{sub US}-7 h {center_dot} ft{sup 2} {center_dot} F/BTU (R{sub SI}-1.2 m{sup 2} {center_dot} K/W) fiberglass batts; (B) a layer of PEPs and one layer of the fiberglass batts; (C) four layers of the fiberglass batts; and (D) an average 4.1 in. (10.4 cm) thick layer of blown-in rock wool at an average density of 2.4 lb/ft{sup 3} (38 kg/m{sup 3}). Effects of additional sheathing were determined for Configurations B and C. With Configuration D over the ceiling, two layers of expanded polystyrene (EPS) boards, each about the same thickness as the PEPs, were installed over the trusses instead of the roof. Aluminum foils facing the attic and over the top layer of EPS were added. The top layer of EPS was then replaced by PEPs.

Petrie, T.W.; Kosny, J.; Childs, P.W.

1996-03-01

53

IMPROVED ROOF STABILIZATION TECHNOLOGIES  

SciTech Connect

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.

M.A. Ebadian, Ph.D.

1999-01-01

54

Investigating and analysing the energy and environmental performance of an experimental green roof system installed in a nursery school building in Athens, Greece  

Microsoft Academic Search

This paper deals with the experimental investigation and analysis of the energy and environmental performance of a green roof system installed in a nursery school building in Athens. The investigation was implemented in two phases. During the first phase, an experimental investigation of the green roof system efficiency was presented and analysed, while in the second one the energy savings

M. Santamouris; C. Pavlou; P. Doukas; G. Mihalakakou; A. Synnefa; A. Hatzibiros; P. Patargias

2007-01-01

55

Thermal Performance of Uninsulated and Partially Filled Wall Cavities: Preprint  

SciTech Connect

Low-rise, wood-framed homes are the most common type of residential structures in the United States. Wood wall construction supports roofs efficiently and provides a stable frame for attaching interior and exterior wall coverings. Wall cavities are prevalent and increase thermal resistance, particularly when they are filled with insulating material. This paper describes detailed computational fluid dynamics modeling to evaluate the thermal performance of uninsulated or partially filled wall cavities and accounts for conduction through framing, convection, and radiation. Parameters are ambient outdoor temperature, cavity surface emissivity, cavity aspect ratio, and insulation height. Understanding the thermal performance of uninsulated or partially insulated wall cavities is essential for conserving energy in residential buildings. The results can serve as input for building energy simulation tools such as DOE2 and EnergyPlus for modeling the temperature dependent energy performance of new and older homes with uninsulated or partially insulated walls.

Ridouane, E. H.; Bianchi, M.

2011-08-01

56

Thermal and mechanical properties of cellular polystyrene and polyurethane insulation materials aged on a flat roof in hot-dry climate  

Microsoft Academic Search

Cellular polymers, which have been increasingly used for thermal insulation of external walls and roofs since the 1970s, degrade in some cases. The heat transmission of a cellular polymer insulator, the k value, is predominantly dependent on the heat conduction of the air or gas remaining in the cells. An insulator may be aged and start transmitting more energy due

Ozkan; E Ozkan

1994-01-01

57

Comparative Evaluation of the Impact of Roofing Systems on Residential Cooling Energy Demand in Florida  

Microsoft Academic Search

Roof and attic thermal performance exert a powerful influence on cooling energy use in Florida homes. The Florida Power and Light Company and the Florida Solar Energy Center instrumented six side-by-side Habitat homes in Ft. Myers, Florida with identical floor plans and orientation, R-19 ceiling insulation, but with different roofing systems designed to reduce attic heat gain. A seventh house

Danny Parker; Jeffrey Sonne; John Sherwin

58

Thermal performance of ground-coupled desert buildings  

SciTech Connect

Results of a computer simulation study of ground-coupled buildings in desert regions are presented. Using finite difference models, the computer program SPICE was used to analyze two-dimensional thermal networks when various parameters of the system were varied. The 150-m/sup 2/ building's annual performance was found to be sensitive to the fenestration amount and orientation, to the depth of soil around the building, and to the insulation amount and placement. However, varying the soil's thermal properties and berming as opposed to burying the building to the same depth had little influence on the annual performance. In order to trace the performance trends in more detail, soil isotherms and monthly heat balances were computer to compare the behavior of a high-mass above-grade building that is well-insulated to a high-mass ground-coupled structure that has only roof insulation.

Bircher, T.L.

1981-07-01

59

Development of a new roof bolt technology to improve gate-road performance  

SciTech Connect

Hilti has developed, in conjunction with Foundation Coal, a self-drilling bolt that cuts roof bolting times. The system uses a wet, self-drilling, hollow bolt technology with a self-contained resin cartridge. The resin is dispensed using an injection adapter that provides the high pressure water needed to dispense the resin. The OneStep roof bolt contains an axially shifting mixer that ensures the resin is properly mixed as it exits the water ports near the end of the bolt near the drill head. This eliminates the opportunity for plastic materials to interface between the strata and the bolt. In 2004 the OneStep Bolt was successfully installed in DSK's Prosper Haniel Colliery in Germany, achieving a 42% reduction in single-boom roof bolt cycle time and a 36% reduction in twin-boom roof bolt cycle time. Foundation Coal will be installing 2000 6 ft active bolts in one of the North Appalachian longwall locations. 1 fig.

Caggiano, V.; Rauch, G.; Beck, K.-D.; Chen, J. [Hilti, Inc. (United States)

2005-10-01

60

Evaluating Performance of a Green Roof System with Different Growing Mediums Sedum Species and Fertilizer Treatments  

Microsoft Academic Search

ABSTRACT Although green roofs have been utilized in Europe for many years, the technology is relatively new to the Midwestern United States. Forests and grasslands are rapidly being replaced with impervious surfaces as urbanization increases. This increase in impervious surface area can cause an increase in storm water runoff and the urban heat island effect. I have evaluated the effects

K. Luckett; V. Jost; S. Morgan; T. Yan; W. Retzlaff; Jost Greenhouses

61

EURECA thermal control flight performance  

NASA Astrophysics Data System (ADS)

The European Retrievablle Carrier (EURCA) at the time of writing is completeing its mission in low Earth orbit, waiting for the retrieval launch of the Shuttle STS-57. EURCA has completed already to a large extent its scientific operations and has undergone to a series of various orbital phases. The thermal control performances are addressed in this paper on the basis of the presently flown mission. The thermal control achievements are evaluated by comparing them with the analytical predictions performed. Temperature characteristics are analyzed, as well as operational aspects of the thermal design. Particular aspects are addressed in more detail, especially in those areas where the EURECA thermal control is peculiar, like the active cooling loop. Preliminary results of the impact of the cooling loop on the microgravity environment are also presented.

Hahn, Wolfgang; Racca, Giuseppe D.; Blackwood, Angus

62

Structural stability vs. thermal performance: old dilemma, new solutions  

SciTech Connect

In many building envelopes, actual thermal performance falls quite a bit short of nominal design parameters given in standards. Very often only windows, doors, and a small part of the wall area meet standards requirements. In the other parts of the building envelope, unaccounted thermal bridges reduce the effective thermal resistance of the insulation material. Such unaccounted heat losses compromise the thermal performance of the whole building envelope. For the proper analysis of the thermal performance of most wall and roof details, measurements and three-dimensional thermal modeling are necessary. For wall thermal analysis the whole-wall R-value calculation method can be very useful. In ties method thermal properties of all wall details are incorporated as an area weighted average. For most wall systems, the part of the wall that is traditionally analyzed, is the clear wall, that is, the flat part of the wall that is uninterrupted by details. It comprises only 50 to 80% of the total area of the opaque wall. The remaining 20 to 50% of the wall area is not analyzed nor are its effects incorporated in the thermal performance calculations. For most of the wall technologies, traditionally estimated R-values are 20 to 30% higher than whole-wall R-values. Such considerable overestimation of wall thermal resistance leads to significant errors in building heating and cooling load estimations. In this paper several examples are presented of the use of the whole-wall R-value procedure for building envelope components. The advantages of the use of the whole wall R-value calculation procedure are also discussed. For several building envelope components, traditional clear-wall R-values are compared with the results of whole-wall thermal analysis to highlight significant limits on the use of the traditional methods and the advantages of advanced computer modeling.

Kosny, J.; Christian, J.E.

1996-10-01

63

Improved roof stabilization technologies  

SciTech Connect

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

Ebadian, M.A.

1998-01-01

64

Final Report on the Development of a Thermal Store and a Solar Blind for Use in Conservatories and Glazed Roof Spaces.  

National Technical Information Service (NTIS)

The program to evaluate the performance of glazed roof spaces of varying pitches fitted with a solar blind and phase change storage materials has been completed. The performance was measured over the heating period October 1982 to April 1983 and operated ...

D. Stewart P. J. C. Kent K. I. Guthrie

1985-01-01

65

Sustainable roofs with real energy savings  

SciTech Connect

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.

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

1996-12-31

66

Effect of double layer phase change material in building roof for year round thermal management  

Microsoft Academic Search

Efficient and economical technology that can be used to store large amounts of heat or cold in a definite volume is the subject of research for a long time. Latent heat storage in a phase change material (PCM) is very attractive because of its high-energy storage density and its isothermal behavior during the phase change process. Thermal storage plays a

A. Pasupathy; R. Velraj

2008-01-01

67

Energy Analysis of Ventilated Roof  

Microsoft Academic Search

\\u000a The thermal performance of the building envelope is an important requirement for guaranteeing both a comfortable indoor climate\\u000a and building’s energy efficiency.\\u000a \\u000a \\u000a Ventilated facades and ventilated roofs could be considered as a passive cooling system that contribute to realize low energy\\u000a building.\\u000a \\u000a \\u000a \\u000a The energy advantages provided by the ventilation of structures, during the summer, is the reduction of the cooling

F. Patania; A. Gagliano; F. Nocera; A. Ferlito; A. Galesi

68

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

SciTech Connect

Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal, potash, salt etc. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on such information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. More field tests have been performed. A trendline analysis method has been developed. This method would improve the accuracy in detecting the locations of fractures and in determining the rock strength.

Syd S. Peng

2003-04-15

69

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

SciTech Connect

Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal, potash, salt etc. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on such information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. Additional field tests have been performed. It is found that the drilling power can be used as a supplementary method for detecting voids/fractures and rock interfaces.

Syd S. Peng

2003-01-15

70

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

SciTech Connect

Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal, potash, salt etc. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on such information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. Additional field tests have been performed in this quarter. The development of the data interpretation methodology and other related tasks are still continuing.

Syd S. Peng

2002-10-15

71

AN EXPERIMENTAL INVESTIGATION OF AIR FLOW AND HEAT TRANSFER IN ROOF-INTEGRATED PHOTOVOLTAIC THERMAL SYSTEMS  

Microsoft Academic Search

Designs and configurations of building-integrated photovoltaic thermal (BIPV\\/T) air systems are based on the type of PV modules, the location, and the geometry of the surface on which the modules are to be mounted. Modeling of BIPV\\/T systems requires knowledge of the local and average heat transfer coefficients for the prediction of temperature distribution and, the evaluation of the energy

Diarra D. C; Candanedo L; Harrison S. J; Athienitis A

72

Increasing roof bolter operator awareness to risks of falling roof material during the bolting cycle  

Microsoft Academic Search

The reduction of injuries due to falls of roof material is a longtime concern of the mining industry. Bolter operators are continually exposed to rib and roof falls as they perform their normal work tasks. Massive roof falls rather than the typical small falls have been the traditional focus of mine safety practitioners. However, falls of smaller amounts of roof

M. J. Klishis; R. C. Althouse; G. M. Lies; L. A. Layne

1993-01-01

73

Mathematical Modeling of Roof Systems.  

National Technical Information Service (NTIS)

It has been a long hiatus since the first assemblage of roof modelers in November 1981. The Proceedings of that workshop have stood as the only dedicated testament of the attempts to formalize roofing performance into mathematical precepts and formulas. N...

1988-01-01

74

Roof bolting without injury. [Glossary included  

Microsoft Academic Search

The art of roof bolting is an important segment of the mining cycle in underground coal mining. Too many accidents occur that can be attributed to the roof bolting process. Too often the Roof Bolter Operator is not cognizant of the art, or drilling techniques, nor the safety procedures to perform the duties effectively and safely. This manual offers those

1992-01-01

75

Guidelines for Inspecting Your Roof Systems.  

ERIC Educational Resources Information Center

|Provides guidelines for inspecting the roof of a facility. Suggests that periodic roof inspections should be performed on a quarterly or semi-annual basis and after severe storms. Proactively identifying potential problem areas is the best defense against roof leaks. (SLD)|

Watkins, Daniel L.

2003-01-01

76

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

SciTech Connect

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 designs. Numerical simulations were performed to investigate the mechanisms of modern roof bolting systems including both the tension and fully grouted bolts. Parameters to be studied are: bolt length, bolt spacing, bolt size/strength, grout annulus, in-situ stress condition, overburden depth, and roof geology (massive strata, fractured, and laminated or thinly-bedded). Based on the analysis of the mechanisms of both bolting systems and failure modes of the bolted strata, roof bolting design criteria and programs for modern roof bolting systems were developed. These criterion and/or programs were combined with the MRGIS for use in conjunction with roof bolt installation.

Syd S. Peng

2005-10-01

77

Guide for Airborne Infrared Roof Moisture Surveys.  

National Technical Information Service (NTIS)

This report presents guidance for the conduct of aerial roof moisture surveys using thermal infrared (IR) scanner systems. Specific information is presented concerning assembly of relevant data prior to the thermal IR imagery acquisition, planning the ima...

L. E. Link

1978-01-01

78

Understanding Roofing Systems.  

ERIC Educational Resources Information Center

|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)|

Michelsen, Ted

2001-01-01

79

Performance of a solar dryer using hot air from roof-integrated solar collectors for drying herbs and spices  

Microsoft Academic Search

A solar dryer for drying herbs and spices using hot air from roof-integrated solar collectors was developed. The dryer is a bin type with a rectangular perforated floor. The bin has a dimension of 1.0m×2.0m×0.7m. Hot air is supplied to the dryer from fiberglass-covered solar collectors, which also function as the roof of a farmhouse. The total area of the

S. Janjai; P. Tung

2005-01-01

80

Radiation control coatings installed on rough-surfaced built-up roofs -- Initial results  

SciTech Connect

The authors have tracked the solar reflectance and thermal performance of small samples of various radiation control coatings on smooth surfaces for several years on a roof test facility in East Tennessee. The focus is on white coatings because of their potential to weather, causing the solar reflectance to decrease as the coatings age. Support of the federal New Technology Demonstration Program allowed them to extend the study to more samples on smooth surfaces and entire rough-surfaced roofs at a federal facility in the Panhandle of Florida. Two rough-surfaced, moderately well-insulated, low solar reflectance built-up roofs (BURs) were spray-coated with a latex-based product with ceramic beads added to improve solar reflectance. In the first three months after installation, the fresh BUR coatings showed a significant decrease in both the outside-surface temperature and the heat flux through the roof insulation. Average sunlit values were generated to exclude nighttime data, data on cloudy days, and data when the uncoated patch on one roof was more strongly shaded in mid-afternoon on sunny days. The average power demand during occupied periods for the first month with the coating for the building with the thermally massive roof deck was 13% less than during the previous month without the coating. For the other buildings with a lightweight roof deck but high internal loads, there were no clear average power savings due to the coating. The authors are continuing to monitor electricity use in these all-electric buildings to calibrate a model for the peak power and annual energy use of the buildings. Modeling results to be given at the end of the two year project will address the effect of roof R-value, geographic location, and solar reflectance, including the effect of weathering, on the performance of coated roofs. The calibrated models should allow one to segregate site-specific effects such as shading and large thermal mass.

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

1998-01-01

81

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

SciTech Connect

Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal, potash, salt etc. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on such information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. The retrofitting works for a dedicated roof bolter for this research has been completed. The laboratory tests performed using this machine on simulated roof blocks have been conducted. The analysis performed on the testing data showed promising signs to detect the rock interface, fractures, as well as the rock types. The other tasks were progressing as planned.

Syd S. Peng

2001-10-15

82

MHTGR thermal performance envelopes: Reliability by design  

SciTech Connect

This document discusses thermal performance envelopes which are used to specify steady-state design requirements for the systems of the Modular High Temperature Gas-Cooled Reactor to maximize plant performance reliability with optimized design. The thermal performance envelopes are constructed around the expected operating point accounting for uncertainties in actual plant as-built parameters and plant operation. The components are then designed to perform successfully at all points within the envelope. As a result, plant reliability is maximized by accounting for component thermal performance variation in the design. The design is optimized by providing a means to determine required margins in a disciplined and visible fashion.

Etzel, K.T.; Howard, W.W.; Zgliczynski, J.B.

1992-05-01

83

Thermal performance of insulated pipe systems  

Microsoft Academic Search

The thermal performance of insulated pipe systems was measured as a function of insulation and pipe system parameters. Insulation parameters included insulation material, thickness, and air gaps at seams and joints. Pipe system parameters were pipe size, hangers, supports, and operating temperature. Over 150 thermal performance tests were recorded and analyzed over a two-year period. Test results show a 15

1981-01-01

84

Thermal performance of insulated pipe systems  

Microsoft Academic Search

The thermal performance of insulated pipe systems was measured as a function of insulation and pipe system parameters. Insulation parameters included insulation material, thickness, and air gaps at seams and joints. Pipe system parameters were pipe size, hangers, supports, and operating temperature. Over 150 thermal performance tests were recorded and analyzed over a two-year period. Test results show a 15%

J. M. Jr

1983-01-01

85

Thermal Performance Challenges from Silicon to Systems  

Microsoft Academic Search

The demand for high-performance microprocessors has resulted in an escalation of power dissipation as well as heat flux at the silicon level. At the same time, the desire for smaller form-factor chassis and lower silicon operating temperatures is compounding the thermal challenge. Thermal design for a microprocessor can no longer be treated in isolation. Power and performance trade offs and

Ram Viswanath; Vijay Wakharkar; Vassou Lebonheur

2000-01-01

86

VEGETATED ROOFS FOR URBAN ECOSYSTEM REMEDIATION: PERFORMANCE AND POLICY IN THE TANYARD BRANCH WATERSHED  

Microsoft Academic Search

Urban land area in the United States is projected to increase to 8.1% of total land area by the year 2050. These human-dominated environments create conditions that degrade both terrestrial and aquatic ecosystems. If cities are to reduce their environmental impact, innovative practices must be developed that replace ecosystem services lost during the urbanization process. This study evaluated the performance

TIMOTHY L. CARTER

87

Occupant dynamics in rollover crashes: influence of roof deformation and seat belt performance on probable spinal column injury.  

PubMed

Motor vehicle crashes are the leading cause of death in the United States for people ages 3-33, and rollover crashes have a higher fatality rate than any other crash mode. At the request and under the sponsorship of Ford Motor Company, Autoliv conducted a series of dynamic rollover tests on Ford Explorer sport utility vehicles (SUV) during 1998 and 1999. Data from those tests were made available to the public and were analyzed in this study to investigate the magnitude of and the temporal relationship between roof deformation, lap-shoulder seat belt loads, and restrained anthropometric test dummy (ATD) neck loads. During each of the three FMVSS 208 dolly rollover tests of Ford Explorer SUVs, the far-side, passenger ATDs exhibited peak neck compression and flexion loads, which indicated a probable spinal column injury in all three tests. In those same tests, the near-side, driver ATD neck loads never predicted a potential injury. In all three tests, objective roof/pillar deformation occurred prior to the occurrence of peak neck loads (F ( z ), M ( y )) for far-side, passenger ATDs, and peak neck loads were predictive of probable spinal column injury. The production lap and shoulder seat belts in the SUVs, which restrained both driver and passenger ATDs, consistently allowed ATD head contact with the roof while the roof was contacting the ground during this 1000 ms test series. Local peak neck forces and moments were noted each time the far-side, passenger ATD head contacted ("dived into") the roof while the roof was in contact with the ground; however, the magnitude of these local peaks was only 2-13% of peak neck loads in all three tests. "Diving-type" neck loads were not predictive of injury for either driver or passenger ATD in any of the three tests. PMID:17641975

Bidez, Martha W; Cochran, John E; King, Dottie; Burke, Donald S

2007-07-20

88

Occupant Dynamics in Rollover Crashes: Influence of Roof Deformation and Seat Belt Performance on Probable Spinal Column Injury  

PubMed Central

Motor vehicle crashes are the leading cause of death in the United States for people ages 3–33, and rollover crashes have a higher fatality rate than any other crash mode. At the request and under the sponsorship of Ford Motor Company, Autoliv conducted a series of dynamic rollover tests on Ford Explorer sport utility vehicles (SUV) during 1998 and 1999. Data from those tests were made available to the public and were analyzed in this study to investigate the magnitude of and the temporal relationship between roof deformation, lap–shoulder seat belt loads, and restrained anthropometric test dummy (ATD) neck loads. During each of the three FMVSS 208 dolly rollover tests of Ford Explorer SUVs, the far-side, passenger ATDs exhibited peak neck compression and flexion loads, which indicated a probable spinal column injury in all three tests. In those same tests, the near-side, driver ATD neck loads never predicted a potential injury. In all three tests, objective roof/pillar deformation occurred prior to the occurrence of peak neck loads (Fz, My) for far-side, passenger ATDs, and peak neck loads were predictive of probable spinal column injury. The production lap and shoulder seat belts in the SUVs, which restrained both driver and passenger ATDs, consistently allowed ATD head contact with the roof while the roof was contacting the ground during this 1000 ms test series. Local peak neck forces and moments were noted each time the far-side, passenger ATD head contacted (“dived into”) the roof while the roof was in contact with the ground; however, the magnitude of these local peaks was only 2–13% of peak neck loads in all three tests. “Diving-type” neck loads were not predictive of injury for either driver or passenger ATD in any of the three tests.

Cochran, John E.; King, Dottie; Burke, Donald S.

2007-01-01

89

Analysis of the green roofs cooling potential in buildings  

Microsoft Academic Search

This paper presents a mathematical model yielding a sensible, albeit simplified representation of the dynamic thermal behaviour of actual green roofs. Several parametric sensitivity analyses have been carried out to assess the cooling potential of green roofs in summer. The main conclusion of these analyses is that green roofs do not act as cooling devices but as insulation ones, reducing

Elena Palomo Del Barrio

1998-01-01

90

Thermal performance of three solar air heaters  

Microsoft Academic Search

This paper reports the thermal analysis and the results of thermal performance tests of solar air heaters with V-corrugated absorber plates. Six collector units were used to test three collector types: (a) flow over the absorber, (b) flow on both sides of the absorber, and (c) flow under the absorber. Paired simultaneous testing was used for collectors of the same

B. F. Parker; M. R. Lindley; D. G. Colliver; W. E. Murphy

1993-01-01

91

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

SciTech Connect

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

Syd S. Peng

2003-07-15

92

Performance and testing of thermal interface materials  

Microsoft Academic Search

The increasing power and reduced die size of CPUs used in computers increases a need for significantly improved thermal interface materials (TIM). The TIM is used to reduce contact resistance at the CPU–heat sink interface. This work provides a state-of-the-art assessment on ‘thermal interface materials’, including fundamentals, materials used, their performance, and how interface resistance is measured. The performance of

J. P. Gwinn; R. L. Webb

2003-01-01

93

Transmutation Fuel Performance Code Thermal Model Verification  

SciTech Connect

FRAPCON fuel performance code is being modified to be able to model performance of the nuclear fuels of interest to the Global Nuclear Energy Partnership (GNEP). The present report documents the effort for verification of the FRAPCON thermal model. It was found that, with minor modifications, FRAPCON thermal model temperature calculation agrees with that of the commercial software ABAQUS (Version 6.4-4). This report outlines the methodology of the verification, code input, and calculation results.

Gregory K. Miller; Pavel G. Medvedev

2007-09-01

94

Steel-framed buildings: Impacts of wall detail configurations on the whole wall thermal performance  

SciTech Connect

The main objective of this paper is the influence of architectural wall details on the whole wall thermal performance. Whole wall thermal performance analysis was performed for six light gage steel-framed wall systems (some with wood components). For each wall system, all wall details were simulated using calibrated 3-D finite difference computer modeling. The thermal performance of the six steel-framed wall systems included various system details and the whole wall system thermal performance for a typical single-story ranch house. Currently, predicted heat losses through building walls are typically based on measurements of the wall system clear wall area using test methods such as ASTM C 236 or are calculated by one of the procedures recommended in the ASHRAE Handbook of Fundamentals that often is carried out for the clear wall area exclusively. In this paper, clear wall area is defined as the part of the wall system that is free of thermal anomalies due to building envelope details or thermally unaffected by intersections with other surfaces of the building envelope. Clear wall experiments or calculations normally do not include the effects of building envelope details such as corners, window and door openings, and structural intersections with roofs, floors, ceilings, and other walls. In steel-framed wall systems, these details typically consist of much more structural components than the clear wall. For this situation, the thermal properties measured or calculated for the clear wall area do not adequately represent the total wall system thermal performance. Factors that would impact the ability of today`s standard practice to accurately predict the total wall system thermal performance are the accuracy of the calculation methods, the area of the total wall that is clear wall, and the quantity and thermal performance of the various wall system details.

Kosny, J.; Desjarlais, A.O.; Christian, J.E.

1998-06-01

95

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

SciTech Connect

Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal, potash, salt etc. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on such information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. More laboratory tests have been performed in this quarter. The analysis performed on the testing data showed: (1) abnormal rotational accelerations can be used as the indicator of the rock interfaces, and (2) the sharp drops of drilling thrust and torque agree well with the locations of fractures.

Syd S. Peng

2002-04-15

96

Comparative studies on different type of roof ponds for cooling purposes: litera- ture review  

Microsoft Academic Search

Bioclimatic approach gives attention to the design of roof since it is commonly the building element which is most exposed. Some of the most favorable roof cool- ing techniques are roof ponds which appear to influence the thermal behavior of roof through different processes including evaporation, radiation and conduction. Large air-conditioning energy savings were estimated, reach- ing 100% in a

A. Spanaki

97

Effect of moisture on thermal resistance of some insulations in a flat roof under field-type conditions  

SciTech Connect

Specimens of glass fiber, phenolic foam, and extruded polystyrene foam insulation with moisture contents ranging up to about 25% by volume were mounted in the roof of an experimental building. The interior of the building was maintained at about 21/sup 0/C and normal weather conditions prevailed outside. Thermocouples were located at the upper and lower surface of each insulation specimen and at the quarter points of some specimens. A calibrated heat flow meter was used to measure heat flow through each specimen continuously for a period ranging from about 7-1/2 to 18 months for wet specimens and somewhat less for some of the dry ones. Heat flow rates were plotted against temperature difference using daily arithmetic averages in most cases; two-week averages were used in a few cases. For open-cell and fibrous insulations of 20% moisture content, heat flow rates exceeded rates for dry insulation by a factor of two or more. The data points were scattered. Inspection suggested that this was partly owing to moisture distribution, which affected the rate of heat flow at a given temperature difference. Measurements at the quarter points provided information about temperature gradients along the path of heat flow, and hence about moisture distribution in the insulation. These results suggested that moisture migrated to the upper layers in the wintertime, leaving the lower layers nearly dry. Ratios of heat flow in wet and dry specimens were in fairly good agreement with those obtained by other investigators.

Hedlin, C.P.

1983-01-01

98

Effect of moisture on thermal resistance of some insulations in a flat roof under field-type conditions  

SciTech Connect

Specimens of glass fiber, phenolic foam, and extruded polystyrene foam insulation with moisture contents ranging up to about 25 percent by volume were mounted in the roof of an experimental building. The interior of the building was maintained at about 21/sup 0/C and normal weather conditions prevailed outside. Thermocouples were located at the upper and lower surface of each insulation specimen and at the quarter points of some specimens. A calibrated heat flow meter was used to measure heat flow through each specimen continuously for a period ranging from about 7 1/2 to 18 months for wet specimens and somewhat less for some of the dry ones. Heat flow rates were plotted against temperature difference using daily arithmetic averages in most cases; two-week averages were used in a few cases. For open-cell and fibrous insulations of 20 percent moisture content, heat flow rates exceeded rates for dry insulation by a factor of two or more. The data points were scattered. Inspection suggested that this was partly owing to moisture distribution, which affected the rate of heat flow at a given temperature difference. Measurements at the quarter points provided information about temperature gradients along the path of heat flow, and hence about moisture distribution in the insulation These results suggested that moisture migrated to the upper layers in the wintertime, leaving the lower layers nearly dry. Ratios of heat flow in wet and dry specimens were in fairly good agreement with those obtained by other investigators.

Hedlin, C.P.

1981-12-01

99

Technical Analysis and Review: NAHB Thermal Performance Guidelines.  

National Technical Information Service (NTIS)

An analysis of the NAHB Thermal Performance Guidelines for One and Two Family Dwellings is presented, relative to the following thermal performance guideline methodologies: thermal performance in existing homes (conventional); HUD Minimum Property Standar...

1978-01-01

100

Thermal performance of double-skin facade with thermal mass  

NASA Astrophysics Data System (ADS)

In order to mitigate the overheating problem in the warmer seasons, and thereby to improve thermal performance and energy efficiency of the Double-Skin Facade (DSF) system, this study introduced an innovative design approach involving the integration of thermal mass with the air channel of the conventional DSF. Then it proposed a numerical procedure to assess the thermal performance of DSF, and finally investigated the effect of thermal mass on the energy efficiency of such system. The initial step in the assessment procedure proposed the development of base-case models, which were able to predict temperature distribution in the DSF with a venetian blind. So too were the base-case models able to determine heating/cooling loads of the perimeter room for both the mechanically and naturally ventilated DSFs. In this procedure, building energy simulation software was used for base-case development; two distinct models were generated: an airflow model and a thermal model. The nodal, unidirectional airflow network method was applied in the case of the naturally ventilated DSF. The thermal model was a transient control volume method which found temperature distribution in discretized air-channel. The base-cases were verified at two levels: inter-model verification and verification relying on measurements from mechanically and naturally ventilated outdoor test-cells. At both levels, a generally fair agreement was obtained. After this, parametric studies pertaining to the energy performance of the system were conducted on the effect of thermal mass in unison with different air-channel configurations. Considerable energy load reductions were found when thermal mass was used in the air-channel, replacing venetian blind slats for mechanically ventilated DSFs; this held true during both summer and winter. In this configuration depending on the airflow path direction, energy savings from 21% to 26% in summer and from 41% to 59% in winter are achievable in compared with conventional DSF with aluminum venetian blind. The savings were found higher in sunny days than cloudy days. On the other hand, naturally ventilated DSFs combined with thermal mass were not found to be energy efficient in winter due to stack effect and airflow rate increase within the air channel.

Fallahi, Ali

101

LIGHTWEIGHT GREEN ROOF SYSTEMS  

EPA Science Inventory

Applying a Lightweight Green Roof System to a building can achieve in managing storm water runoff, decreasing heat gain, yielding energy savings, and mitigating the heat island effect. Currently, Most green roof systems are considerably heavy and require structural reinforceme...

102

Thermal performance of the ATST secondary mirror  

NASA Astrophysics Data System (ADS)

The Advanced Technology Solar Telescope (ATST) has a 4.24m off-axis primary mirror designed to deliver diffractionlimited images of the sun. Its baseline secondary mirror (M2) design uses a 0.65m diameter Silicon Carbide mirror mounted kinematically by a bi-pod flexure mechanism at three equally spaced locations. Unlike other common telescopes, the ATST M2 is to be exposed to a significant solar heat loading. A thermal management system (TMS) will be developed to accommodate the solar loading and minimize "mirror seeing effect" by controlling the temperature difference between the M2 optical surface and the ambient air at the site. Thermo-elastic analyses for steady state thermal behaviors of the ATST secondary mirror was performed using finite element analysis by I-DEASTM and PCRINGETM for the optical analysis. We examined extensive heat transfer simulation cases and their results were discussed. The goal of this study is to establish thermal models by I-DEAS for an adequate thermal environment. These thermal models will be useful for estimating segment thermal responses. Current study assumes a few sample time dependent thermal loadings to synthesize the operational environment.

Cho, Myung K.; DeVries, Joe; Hansen, Eric

2007-11-01

103

Performance of a building integrated photovoltaic\\/thermal (BIPVT) solar collector  

Microsoft Academic Search

The idea of combining photovoltaic and solar thermal collectors (PVT collectors) to provide electrical and heat energy is an area that has, until recently, received only limited attention. Although PVTs are not as prevalent as solar thermal systems, the integration of photovoltaic and solar thermal collectors into the walls or roofing structure of a building could provide greater opportunity for

T. N. Anderson; M. Duke; G. L. Morrison; J. K. Carson

2009-01-01

104

A compact high performance thermal imager  

Microsoft Academic Search

A compact, low-cost, high-performance thermal imager based on a novel coaxial scanning technique is presented. Design requirements for this imager configuration encompass the avoidance of vignetting and pupil wander in the scanning elements and objective lenses, as well as the maximization of detector cold shielding. The requirements are met by the use of SPRITE IR detectors, and the use of

A. H. Lettington; W. T. Moore

1986-01-01

105

THERMAL PERFORMANCE OF OFFICE BUILDINGS IN GHANA  

Microsoft Academic Search

Using a simulation application and a sample of five existing office buildings, we parametrically explored building features and measures that could improve the thermal performance of office buildings in Kumasi, Ghana. To improve the reliability of the simulation results, the simulation models were calibrated using long-term continuous measurements on environmental conditions (air temperature, relative humidity) inside and in the immediate

Christian Koranteng; Ardeshir Mahdavi

106

Polyurethane-based organic aerogels' thermal performance  

Microsoft Academic Search

A novel type of chemistry based on the use of polyisocyanates which can be turned into heavily cross-linked polyurethanes (PUR), polyureas, polyurethone imines or polyisocyanurates (PIR) to make organic aerogels is now being developed. Feasibility study of the polyisocyanate-based aerogels and various parameter effects on the thermal performance of these materials are described. This paper focuses on the low density

G. Biesmans; D. Randall; E. Francais; M. Perrut

1998-01-01

107

Performance analysis of photovoltaic thermal air heaters  

Microsoft Academic Search

The performance of single-pass and double-pass combined photovoltaic thermal collectors are analyzed with steady-state models. The working fluid is air and the models are based on energy conservation at various nodes of the collector. Closed form solutions have been obtained for the differential equations of both the single-pass and double-pass collectors. Comparisons are made between the performances of the two

K. Sopian; K. S. Yigit; H. T. Liu; S. Kakaç; T. N. Veziroglu

1996-01-01

108

Solar collector roof  

SciTech Connect

A solar roof is disclosed for providing air heated by solar energy to the interior of a prefabricated building of the type having a relatively low pitched roof structure formed by a plurality of interlocking ribbed roof panels. A solar radiation transmissive glazing is attached between the roof panel ribs or other support members to form air passageways. A duct-like inlet plenum communicates with the inlet of each passageway for selectively directing air from inside or outside of the building passageways. A duct-like exhaust plenum communicates with the outlet of each passageway for directing heated air to the building interior. The roof surface may be provided with a darkened coating to increase the absorptivity of the surface and increase the collecting efficiency. The glazing material may be thin flexible solar radiation transmissive sheets or relatively rigid panels of solar radiation transmissive material. The solar roof may be retrofitted to an existing roof structure to provide supplemental solar heating capability.

Marossy, G.; Mueller, W.E.

1983-07-19

109

Temperature regime of planted roofs compared with conventional roofing systems  

Microsoft Academic Search

This paper analyses the temperature regime of an existing green roof and a sod roof, compared with a modified bituminous membrane roof and a steel sheet roof. The measurement period was from June 2004 to December 2007 at three different measurement locations. Results are given both seasonally and daily; indexes to characterize the effects of the temperature of planted roofs

Alar Teemusk; Ülo Mander

2010-01-01

110

Extensive Green Roofs in London  

Microsoft Academic Search

This paper gives an overview of extensive green roofs in London and considers their potential to benefit the conservation of biodiversity. Categories of green roofs described include grass roofs of the early 1990s; mass-produced Sedum roofs, first installed in the late 1990s; and recently installed roofs made from crushed concrete and brick designed to provide habitat for the rare black

Gary Grant

111

Potential energy cost savings by use of building roofs as thermal storage of a multi-storied building  

NASA Astrophysics Data System (ADS)

The thermal mass of a building has been used for more than two decades to shift the peak cooling load occurring during the day time to evening or night time. This is typically accomplished by use of concrete slabs embedded with pipes carrying hot or chilled water to meet the heating or cooling load, respectively. The water temperature drops across the coils and the frequency and intensity of room air circulation can be varied, along with controlling the gains through the windows, to shift the peak load hours to the nighttime when energy costs are cheaper and electric demands are lower. This thesis deals with the transient finite element heat transfer analysis of a concrete slab embedded with pipes circulating heated or chilled water of a multi-storied office building. A hypothetical office building in Chattanooga, Tennessee, USA is analyzed with weather data of that locale. The electrical power consumption of such a system operating at milder conditions or evening or night hours is estimated by use of hourly weather data. The estimated electric power consumption is then compared to the traditional method of operations. The influence of the wall envelope, including the size and orientation of windows, is considered in reducing the energy gain or loss from the space. The results presented in this thesis identify the potential energy cost savings of such a system as well as challenges involved compared to traditional buildings in commercial applications.

Shelbaya, Ahmad Adam

112

The effect of air infiltration on the thermal performance of a small metal-framed assembly  

SciTech Connect

Innovative construction materials and systems have generated a need for laboratory scale tests to quantify the effect of air leakage on thermal and moisture performance of building assemblies. Some construction materials and systems are inherently more air tight than others. It is desirable to do laboratory scale measurements on alternative systems so as to rank them with respect to air tightness just as they can be ranked with respect to system R-value. Participants in summer 1995 and 1996 workshops for elementary and secondary school science teachers in the Buildings Technology Center (BTC) at the Oak Ridge National Laboratory sought a way to illustrate basic principles of building science in the classroom. They decided to build a small metal-framed assembly with internal volume of 44 ft{sup 3} (1.25 m{sup 3}) and removable wall sheathing. The assembly included a door and window. Although the door and window were made from 4-in. (10.2-cm) thick foam insulation, the requisite framing for them detracted from the thermal performance of the walls and occupied a disproportionately large fraction of the wall area. The floor and roof of the assembly were also well-insulated so that the walls dominated the conduction heat loss through the assembly. The plan was to test thermal performance of the assembly with the sheathing and without it. Thereby the teachers hoped to show the effects of thermal bridges with metal framing as well as practical yet insightful way to reduce their effects.

Petrie, T.W.; Christian, J.E.; Childs, P.W. [Oak Ridge National Lab., TN (United States). Energy Div.

1997-03-01

113

Thermal Performance of Lightweight Solar Housing for Peri-urban Villages  

NASA Astrophysics Data System (ADS)

This study concerns an investigation into the thermal performance of prefabricated lightweight houses for peri-urban villages in the Perth Metropolitan region of Western Australia. Several styles of residence were selected for comparison taken from three constructed ``lifestyle villages''. National Lifestyle Villages Pty Ltd (NLV) is committed to quadruple bottom-line sustainability and the aim was, therefore, to provide indicators of how old and new dwellings compared under the same external conditions. The buildings themselves are prefabricated and brought to site in two halves, framed in steel clad with fibre-cement boarding, roofed in zincalume sheeting, and timber floored with applied fibre-cement sheeting. Although designed using passive solar design principles and other energy conservation measures they possess little thermal mass to improve the thermal performance. Research by the author indicated several feasible and low-budget innovative improvements for future designs, and how best to retrofit existing dwellings. NLV's aim is to provide homes for over 40,000 people in 100 villages Australia-wide by the year 2025. Any improvement in residential thermal performance can be translated not only into energy savings and greenhouse gas reduction on a significant scale, but can enhance comfort levels for residents whilst reducing their energy costs.

Goodfield, D.; Anda, M.; Hammond, R.; Mathew, K.

2007-10-01

114

Condensation Risk of Mechanically Attached Roof Systems in Cold Climate Zones  

SciTech Connect

A white roof, cool roof, is constructed to decrease thermal loads from solar radiation, therefore saving energy by decreasing the cooling demands. Unfortunately, cool roofs with mechanically attached membrane, have shown to have a higher risk of intermediate condensation in the materials below the membrane in certain climates (Ennis & Kehrer, 2011) and in comparisons with similar construction with a darker exterior surface (Bludau, Zirkelbach, & Kuenzel, 2009). As a consequence, questions have been raised regarding the sustainability and reliability of using cool roof membranes in Northern U.S. climate zones. A white roof surface reflects more of the incident solar radiation in comparisons with a dark surface, which makes a distinguished difference on the surface temperature of the roof. However, flat roofs with either a light or dark surface and if facing a clear sky, are constantly losing energy to the sky due to the exchange of infrared radiation. This phenomenon exists both during the night and the day. During the day, if the sun shines on the roof surface, the exchange of infrared radiation typically becomes insignificant. During nights and in cold climates, the temperature difference between the roof surface and the sky can deviate up to 20 C (Hagentoft, 2001) which could result in a very cold surface temperature compared to the ambient temperature. Further, a colder surface temperature of the roof increases the energy loss and the risk of condensation in the building materials below the membrane. In conclusion, both light and dark coated roof membranes are cooled by the infrared radiation exchange during the night, though a darker membrane is more heated by the solar radiation during the day, thus decreasing the risk of condensation. The phenomenon of night time cooling from the sky and the lack of solar gains during the day is not likely the exclusive problem concerning the risk of condensation in cool roofs with mechanically attached membranes. Roof systems with thermoplastic membranes are prone to be more effected by interior air intrusion into the roof construction; both due to the wind induced pressure differences and due to the flexibility and elasticity of the membrane (Molleti, Baskaran, Kalinger, & Beaulieu, 2011). Depending on the air permeability of the material underneath the membrane, wind forces increase the risk of fluttering (also referred as billowing) of the thermoplastic membrane. Expectably, the wind induced pressure differences creates a convective air flow into the construction i.e. Page 2 air intrusion. If the conditions are right, moisture from the exchanging air may condensate on surfaces with a temperature below dew-point. The definite path of convective airflows through the building envelope is usually very difficult to determine and therefore simplified models (K nzel, Zirkelbach, & Scfafaczek, 2011) help to estimate an additional moisture loads as a result of the air intrusion. The wind uplifting pressure in combination with wind gusts are important factors for a fluttering roof. Unfortunately, the effect from a fluctuating wind is difficult to estimate as this is a highly dynamic phenomenon and existing standards (ASTM, 2011a) only take into account a steady state approach i.e. there is no guidance or regulations on how to estimate the air intrusion rate. Obviously, a more detailed knowledge on the hygrothermal performance of mechanically attached cool roof system is requested; in consideration to varying surface colors, roof air tightness, climate zones and indoor moisture supply.

Pallin, Simon B [ORNL

2013-01-01

115

Next Generation Roofs and Attics for Homes  

SciTech Connect

Prototype residential roof and attic assemblies were constructed and field tested in a mixed-humid U.S. climate. Summer field data showed that at peak day irradiance the heat transfer penetrating the roof deck dropped almost 90% compared with heat transfer for a conventional roof and attic assembly. The prototype assemblies use a combination of strategies: infrared reflective cool roofs, radiant barriers, above-sheathing ventilation, low-emittance surfaces, insulation, and thermal mass to reduce the attic air temperature and thus the heat transfer into the home. The prototype assemblies exhibited attic air temperatures that did not exceed the peak day outdoor air temperature. Field results were benchmarked against an attic computer tool and simulations made for the densely populated, hot and dry southeastern and central-basin regions of California. New construction in the central basin could realize a 12% drop in ceiling and air-conditioning annual load compared with a code-compliant roof and attic having solar reflectance of 0.25 and thermal emittance of 0.75. In the hot, dry southeastern region of California, the combined ceiling and duct annual load drops by 23% of that computed for a code-compliant roof and attic assembly. Eliminating air leakage from ducts placed in unconditioned attics yielded savings comparable to the best simulated roof and attic systems. Retrofitting an infrared reflective clay tile roof with 1 -in (0.032-m) of EPS foam above the sheathing and improving existing ductwork by reducing air leakage and wrapping ducts with insulation can yield annual savings of about $200 compared with energy costs for pre-1980 construction.

Miller, William A [ORNL; Kosny, Jan [ORNL

2008-01-01

116

Development of Mitsubishi High Thermal Performance Grid  

NASA Astrophysics Data System (ADS)

Mitsubishi has developed a new zircalloy grid spacer for PWR fuel with higher thermal performance. Computational Fluid Dynamics (CFD) evaluation method has been applied for designing of the new lower pressure loss and higher Departure from Nucleate Boiling (DNB) benefit grid spacer. Reduction of pressure loss of grid structures has been examined by CFD. Also, CFD has been developed as a design tool to predict the coolant mixing ability of vane structures, which is to compare the relative peak spot temperatures around fuel rods at the same heat flux condition. Prototype grids were manufactured and several tests, which were pressure loss measurements, cross-flow measurements and freon DNB tests, were conducted to verify CFD predictions. It is concluded that the applicability of the CFD evaluation method for the thermal hydraulic design of the grid is confirmed.

Ikeda, Kazuo; Hoshi, Masaya

117

Roof drilling system  

Microsoft Academic Search

A roof-drilling system for use in subterranean mining applications and the like in which the drill head of a roof drilling machine is arranged such that the receiving cavity of its chuck is configured having a lost motion association with the drive-in portion of starter and driver drill steel rods. The lower surface of a retainer fixed to the drill

McSweeney

1980-01-01

118

Elastomeric Roofing: A Survey.  

National Technical Information Service (NTIS)

In recent years the use of elastomeric roofing systems in the United States has been increasing. A survey was conducted to ascertain the current state-of-the art of these roofing systems. The information obtained in the survey was gathered from a literatu...

W. J. Rossiter R. G. Mathey

1978-01-01

119

Thermal performance of the MFTF magnets  

NASA Astrophysics Data System (ADS)

A yin-yang pair of liquid-helium (LHe) cooled, superconducting magnets were tested as part of a series of tests with the mirror fusion test facility. These tests were performed to determine the success of engineering design used in major systems of the MFTF and to provide a technical base for rescoping from a single-mirror facility (MFTF) to the large tandem-mirror configuration (MFTF-B) now under construction. The magnets were cooled, operated at their design current and magnetic field, and warmed to atmospheric temperature. Their thermal behavior during these tests is described.

Vansant, J. H.

120

THERMAL PERFORMANCE ANALYSIS FOR WSB DRUM  

SciTech Connect

The Nuclear Nonproliferation Programs Design Authority is in the design stage of the Waste Solidification Building (WSB) for the treatment and solidification of the radioactive liquid waste streams generated by the Pit Disassembly and Conversion Facility (PDCF) and Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF). The waste streams will be mixed with a cementitious dry mix in a 55-gallon waste container. Savannah River National Laboratory (SRNL) has been performing the testing and evaluations to support technical decisions for the WSB. Engineering Modeling & Simulation Group was requested to evaluate the thermal performance of the 55-gallon drum containing hydration heat source associated with the current baseline cement waste form. A transient axi-symmetric heat transfer model for the drum partially filled with waste form cement has been developed and heat transfer calculations performed for the baseline design configurations. For this case, 65 percent of the drum volume was assumed to be filled with the waste form, which has transient hydration heat source, as one of the baseline conditions. A series of modeling calculations has been performed using a computational heat transfer approach. The baseline modeling results show that the time to reach the maximum temperature of the 65 percent filled drum is about 32 hours when a 43 C initial cement temperature is assumed to be cooled by natural convection with 27 C external air. In addition, the results computed by the present model were compared with analytical solutions. The modeling results will be benchmarked against the prototypic test results. The verified model will be used for the evaluation of the thermal performance for the WSB drum.

Lee, S

2008-06-26

121

A green roof model for building energy simulation programs  

Microsoft Academic Search

A physically based model of the energy balance of a vegetated rooftop has been developed and integrated into the EnergyPlus building energy simulation program. This green roof module allows the energy modeler to explore green roof design options including growing media thermal properties and depth, and vegetation characteristics such as plant type, height and leaf area index. The model has

D. J. Sailor

2008-01-01

122

Simulation of thermodynamic transmission in green roof ecosystem  

Microsoft Academic Search

Green roofs entail the creation of vegetated space on the top of artificial structures. They can modify the thermal properties of buildings to bring cooling energy conservation and improve human comfort. This study evaluates the thermodynamic transmission in the green roof ecosystem under different vegetation treatments. Our model simulation is based on the traditional Bowen ratio energy balance model (BREBM)

Hongming He; C. Y. Jim

2010-01-01

123

Protected Membrane Roofs: A Sustainable Roofing Solution.  

ERIC Educational Resources Information Center

|Examines the benefits of protected membrane roofing (PMR) for school buildings. PMR uses an upside-down approach, where the insulation is placed on top of the waterproofing membrane to improve membrane effectiveness, reduce ultraviolet degradation, and improve insulation efficiency. The article explains what makes PMR sustainable, focusing on…

Roodvoets, David L.

2003-01-01

124

Development of a Roof Savings Calculator  

Microsoft Academic Search

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

Joshua Ryan New; William A Miller; Joe Huang; Ender Erdem

2011-01-01

125

Approaches to analyzing the thermal performance of commercial buildings  

Microsoft Academic Search

Building thermal performance monitoring involves acquiring appropriate data, adjusting a thermal model to that data, and using the adjusted thermal model to answer questions regarding actual or potential building thermal operation. A monitoring method is thus classified by data type, model used, and calculation procedures. Data types are based upon the aggregation level of inherent spatial and temporal variations. The

Burch

1984-01-01

126

Roof bolting equipment & technology  

SciTech Connect

Technology provides an evaluator path to improvement for roof bolting machines. Bucyrus offers three different roof bolts models for various mining conditions. The LRB-15 AR is a single-arm boiler recommended for ranges of 32 inches and above; the dual-arm RB2-52A for ranges of 42 inches and above; and the dual-arm RB2-88A for ranges of 54 inches and above. Design features are discussed in the article. Developments in roof bolting technology by Joy Mining Machinery are reported. 4 photos.

Fiscor, S.

2009-04-15

127

Coupling heat flux dynamics with meteorological conditions in the green roof ecosystem  

Microsoft Academic Search

Green roofs can notably modify the thermal properties of the building envelope and adjacent air to bring environmental benefits. This study investigates the heat flux dynamics of the tropical green roof ecosystem to provide a scientific basis for design and management. Green roof experimental plots were established to monitor the total solar radiation, net radiation, and micrometeorological parameters. The data

C. Y. Jim; Hongming He

2010-01-01

128

Thermal performance limits of polymer composite pin fin heat sinks  

Microsoft Academic Search

The thermal performance limits of air cooled heat sinks made of a polyphenylene sulphide composite (PPS, 20W\\/m-K), are predicted and compared to aluminum and copper pin fin heat sinks, using a defined heat sink volume and a range of pumping powers. The thermal performance is analytically predicted across an extensive parametric space in terms of the primary thermal metrics and

Raj Bahadur; Avram Bar-Cohen

2005-01-01

129

Using MCD-DVS For Dynamic Thermal Management Performance Improvement  

Microsoft Academic Search

With chip temperature being a major hurdle in microprocessor design, techniques to recover the performance loss due to thermal emergency mechanisms are crucial in order to sustain performance growth. Many techniques for power reduction in the past and some on thermal management more recently have contributed to alleviate this problem. Probably the most important thermal control technique is dynamic voltage

Pedro Chaparro; Grigorios Magklis; José González; Antonio González

2006-01-01

130

Lightweight Hydraulic Roof Support.  

National Technical Information Service (NTIS)

This citation summarizes a one-page announcement of technology available for utilization. A 22-ton capacity temporary mine roof support light enough to be easily lifted and transported manually from one place to another was developed. The lightweight hydr...

1983-01-01

131

Performance evaluation of Automatic Extraction System. Volume V. Geotechnical investigations of the roof conditions in the area mined by the AES machine. Final technical report  

SciTech Connect

This report presents the results of an in-depth geotechnical investigation aimed at assessing the roof, floor, and coal pillar conditions in the area mined by an experimental Automatic Extraction System (AES), built by National Mine Service Co. The study included diamond core drilling, borescope observations, and detailed engineering geological mapping in Consolidation Coal's McElroy coal mine in West Virginia. The field investigations were accompanied by regional geology studies involving aerial photography and lineament analysis as well as by laboratory testing of 103 rock and coal samples. The roof conditions were interpreted by means of an engineering rock mass classification system, known as the Geomechanics Classification. It was found that the roof quality in the areas mined by the AES machine was poor and that the action of the AES support beams could be detrimental to the overall roof stability. Improvements in the procedures for evaluating future AES-type mining are suggested.

Bieniawski, Z.T.; Rafia, F.; Newman, D.A.

1980-07-01

132

Waterproof that Roof!  

NSDL National Science Digital Library

In this activity, learners explore how engineers have improved roofing designs and materials in order to protect the contents of buildings. Learners explore the hydrophobic effect, and learn about nanotechnology. Then, they work in teams to design a roof structure both in terms of shape and materials to protect a box and its contents from a simulated rainstorm. Teams build, test, and evaluate their designs and those of other teams.

Ieee

2013-07-08

133

Science Nation: Green Roofs  

NSDL National Science Digital Library

The rooftops of Manhattan are as varied as the city itself. But on some, something new is taking root--literally! A green roof is a continuous layer of living plants. Looking down several stories from the windows of neighboring buildings, the rooftop resembles a well-manicured, suburban lawn that is simply contained within the boundaries of a flat Manhattan rooftop. Researchers are investigating what benefits green roofs might have on harsh urban environments.

134

FPL roof temperature and moisture model : description and verification  

Treesearch

Comparison of data from model simulation and measured data provided limited ... addition of thermal mass in attic and roof, better algorithms to calculate direct and ... Relative humidity, Mathematical models, Computer software, Attics, Heating.

135

The Influence of Ambient Temperature on Green Roof R-values  

NASA Astrophysics Data System (ADS)

Green roofs can be an effective and appealing way to increase the energy efficiency of buildings by providing active insulation. As plants in the green roof transpire, there is a reduction in heat flux that is conducted through the green roof. The R-value, or thermal resistance, of a green roof is an effective measurement of thermal performance because it can be easily included in building energy calculations applicable to many different buildings and situations. The purpose of this study was to determine if an increase in ambient temperature would cause an increase in the R-value of green roofs. Test trays containing green roof materials were tested in a low speed wind tunnel equipped to determine the R-value of the trays. Three different plant species were tested in this study, ryegrass (Lolium perenne), sedum (Sedum hispanicum), and vinca (Vinca minor ). For each test in this study the relative humidity was maintained at 45% and the soil was saturated with water. The trays were tested at four different ambient temperatures, ranging from room temperature to 120ºF. The resulting R-values for sedum ranged from 1.37 to 3.28 ft2hºF/BTU, for ryegrass the R-values ranged from 2.15 to 3.62 ft2hºF/BTU, and for vinca the R-values ranged from 3.15 to 5.19 ft2hºF/BTU. The average R-value for all the tests in this study was 3.20 ft2hºF/BTU. The results showed an increase in R-value with increasing temperature. Applying an ANOVA analysis to the data, the relationship between temperature and R-value for all three plant species was found to be statistically significant.

Cox, Bryce Kevin

136

The Thermal Performance of School Buildings  

ERIC Educational Resources Information Center

Attempts to compare the thermal environment measured within schools with current prediction methods and the energy used to produce and maintain the thermal environment with that predicted. Argues that a more exact definition of the external climate for design purposes is needed and suggests such a definition. (Author/EA)

O'Sullivan, P. E.; Cole, R. J.

1974-01-01

137

Thermal storage performance analysis on Chinese kangs  

Microsoft Academic Search

Chinese kangs are widely used as a rural home heating system in Northern China by 175 million people. The main features of Chinese kangs include the effective use of thermal mass in kang plate. In this paper, a thermal and airflow model for an elevated kang is developed with a simply consideration of the heat transfer in building envelope. Approximate

Zhi Zhuang; Yuguo Li; Bin Chen

2009-01-01

138

Window performance for human thermal comfort  

Microsoft Academic Search

A method based on the ASHRAE two-node comfort model has been developed for predicting the effect of windows on thermal comfort. The method embodies separate analyses for longwave (thermal infrared) radiation, induced drafts, and solar load effects. Of these three impacts, modeling results demonstrate that longwave exchange between the body and the window is the most significant except for the

Peter Lyons; Dariush Arasteh; Charlie Huizenga

2000-01-01

139

Magellan spacecraft thermal control system design and performance  

Microsoft Academic Search

A thermal control system of the Magellan spacecraft launched on May 4, 1989 to perform radar mapping and other science experiments is described. The thermal control system design required sustained operations near Venus in a three-axis stabilized spacecraft. It is concluded that, despite the constraints imposed by Magellan's thermal degradation, the primary mission goal of mapping at least 70 percent

James C. Neuman; Joseph A. Buescher; Gregory J. Esterl

1993-01-01

140

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

Code of Federal Regulations, 2013 CFR

...Installation of roof support using mining machines with integral roof bolters. 75.205...Installation of roof support using mining machines with integral roof bolters. When...bolts are installed by a continuous mining machine with intregal roof bolting...

2013-07-01

141

Up on the Roof: A Systematic Approach to Roof Maintenance.  

ERIC Educational Resources Information Center

|A systematic roof maintenance program is characterized by carefully prepared long- and short-range plans. An essential feature of a systematic approach to roof maintenance is the stress on preventive measures rather than the patching of leaks. (Author)|

Burd, William

1979-01-01

142

8. Detail of interior roof showing truss bracing and roof ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. Detail of interior roof showing truss bracing and roof plank decking; view to east from approximately the center of the shelter. - Warm River Shelter, Warm River Campground, Ashton, Fremont County, ID

143

5. MAIN BAY SHOWING ROOF CONSTRUCTION, ROOF TRUSS, CLERESTORY MONITOR, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. MAIN BAY SHOWING ROOF CONSTRUCTION, ROOF TRUSS, CLERESTORY MONITOR, AND GIRDER FOR ELECTRIC OVERHEAD TRAVEL CRANE (BOTTOM) - Oldman Boiler Works, Boilershop, 32 Illinois Street, Buffalo, Erie County, NY

144

Rod shop, roof and truss detail showing older pink roof ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Rod shop, roof and truss detail showing older pink roof truss, newer pratt truss, and longitudinal, truss for overhead traveling crane - Chicago, Burlington & Quincy Railroad, Roundhouse & Shops, Broadway & Spring Streets, Aurora, Kane County, IL

145

Up on the Roof: A Systematic Approach to Roof Maintenance.  

ERIC Educational Resources Information Center

A systematic roof maintenance program is characterized by carefully prepared long- and short-range plans. An essential feature of a systematic approach to roof maintenance is the stress on preventive measures rather than the patching of leaks. (Author)

Burd, William

1979-01-01

146

Q-Flex Accelerometer Thermal Performance Study.  

National Technical Information Service (NTIS)

The significance of this investigative effort to the Air Force is in the pursuit of low cost accelerometer with low thermal sensitivity and suitable for strapped down system application. The results of this Air Force research and development program indic...

N. J. Klein D. B. Grindeland B. D. Strachan

1976-01-01

147

Thermal design and performance of HAMSAT  

Microsoft Academic Search

HAMSAT is a micro-satellite for providing satellite-based Amateur Radio services to the national as well as the international community of Amateur Radio Operators (HAMs). Micro-satellites (less than 100kg) are becoming increasingly utilized as an economical means of experimentation and research in orbit. The thermal control of micro-satellite presents unique challenges to the thermal engineer since the mass; power and volume

K. Badari Narayana; V. Venkata Reddy

2007-01-01

148

Green Roofs for Stormwater Runoff Control - Abstract  

EPA Science Inventory

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...

149

Green Roofs for Stormwater Runoff Control  

EPA Science Inventory

¿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...

150

The role of vegetation in regulating stormwater runoff from green roofs in a winter rainfall climate  

Microsoft Academic Search

Extensive green roofs composed of a thin layer of growing medium topped with vegetation can significantly reduce both the timing and magnitude of stormwater runoff relative to a typical impervious roof. However, regional climatic conditions such as seasonality in rainfall and potential evapotranspiration could strongly alter the stormwater performance of green roofs. In this study we evaluate the stormwater performance

Erin Schroll; John Lambrinos; Tim Righetti; David Sandrock

2011-01-01

151

Retractable Roof Greenhouses and Shadehouses  

Treesearch

Description: Open-roof greenhouses provide a natural environment for plant growth when the outdoor weather is suitable and an artificial environment ... Opening the roof over the plants increases light intensity, which can help to control the ...

152

Thermal performance of packed-bed solar air heaters  

Microsoft Academic Search

This paper presents an experimental investigation of the enhancement of thermal performance of solar iar heater having its duct packed with blackened wire-screen matrices. Tests were conducted to cover wide range of influencing parameters including geometry of wire screens, mass flow rates and input solar energy fluxes under actual outdoor conditions. Effect of these parameters on the thermal performance has

S. P. Sharma; J. S. Saini; H. K. Varma

1991-01-01

153

CLIMATIC VARIABILITY, CLIMATIC CHANGE AND THE THERMAL PERFORMANCE OF BUILDINGS  

Microsoft Academic Search

The building designer has a number of simplified methods at his disposal when investigating the thermal performance of a proposed building. In reality however, the process of interaction between external climate and a building structure is exceedingly complex and only with the advent of powerful computers has the realistic modelling of thermal performance become feasible.Using measured climatic data and a

P. J. Walsh

1976-01-01

154

High-Tech Roof Management.  

ERIC Educational Resources Information Center

|Describes the use of a computerized roof management system (CRMS) for school districts to foster multiple roof maintenance efficiency and cost effectiveness. Highlights CRMS software manufacturer choices, as well as the types of nondestructive testing equipment tools that can be used to evaluate roof conditions. (GR)|

Benzie, Tim

1997-01-01

155

A Monolithic Microconcentrator Receiver For A Hybrid PV-Thermal System: Preliminary Performance  

NASA Astrophysics Data System (ADS)

An innovative hybrid PV-thermal microconcentrator (MCT) system is being jointly developed by Chromasun Inc., San Jose, California, and at the Centre for Sustainable Energy Systems, Australian National University. The MCT aims to develop the small-scale, roof-top market for grid-integrated linear CPV systems. A low profile, small footprint enclosure isolates system components from the environment, relaxing the demands on supporting structures, tracking, and maintenance. Net costs to the consumer are reduced via an active cooling arrangement that provides thermal energy suitable for water and space heating, ventilation, and air conditioning (HVAC) applications. As part of a simplified, low-cost design, an integrated substrate technology provides electrical interconnection, heat sinking, and mechanical support for the concentrator cells. An existing, high-efficiency, one-sun solar cell technology has been modified for this system. This paper presents an overview of the key design features, and preliminary electrical performance of the MCT. Module efficiencies of up to 19.6% at 20x concentration have been demonstrated.

Walter, D.; Everett, V.; Vivar, M.; Harvey, J.; van Scheppingen, R.; Surve, S.; Muric-Nesic, J.; Blakers, A.

2010-10-01

156

Sound power level study of a roof bolter  

Microsoft Academic Search

The National Institute for Occupational Safety and Health (NIOSH) has initiated a study of a roof bolter to reduce noise exposure to mine roof-bolter operators. An important segment of this research entails determining the affect of various drilling configurations on the performance (penetration rate) and sound power emissions when drilling into granite. Test conditions included using various combina- tions of

J. S. Peterson; P. G. Kovalchik; R. J. Matetic

157

Pillar and Roof Span Design Guidelines for Underground Stone Mines.  

National Technical Information Service (NTIS)

A study of pillar and roof span performance in stone mines that are located in the Eastern and Midwestern United States showed that various stability issues can be addressed by appropriate pillar and roof span design. Pillars can be impacted by rock joint...

D. R. Dolinar G. S. Esterhuizen J. L. Ellenberger L. J. Prosser

2011-01-01

158

Numerical Simulation of Electric-Thermal Performance of a Solar Concentrating Photovoltaic\\/Thermal System  

Microsoft Academic Search

Combined photovoltaic\\/thermal system with concentrator is an efficient way to convert more solar radiation into thermal and electric energy and make it in practicable. In this work, A single-pass photovoltaic\\/thermal solar system with three trough concentrators and fins is designed and its electric-thermal performance over arrange of operating conditions is analyzed. The steady state heat transfer models are developed for

Sun Jian; Shi Mingheng

2009-01-01

159

Roofs for Warm Climates.  

National Technical Information Service (NTIS)

This publication is an attempt to deal with the problem, as it concerns the roof, which is perhaps the most important component of all, influencing to a considerable extent the design and construction of the rest of the building. The requirements of flat ...

R. Sperling

1979-01-01

160

Toward safer roof bolting  

SciTech Connect

An automatic roof bolter is being developed by Ingersoll-Rand under a contract with the U.S. Bureau of Mines. A microprocessor in an explosion-proof enclosure commands the numerous operations for drilling a hole and inserting a bolt. The unit can install either resin or mechanical bolts in 4-, 5-, or 6-foot lengths.

Not Available

1983-10-01

161

Performance Evaluation of Automatic Extraction System. Volume V. Geotechnical Investigations of the Roof Conditions in the Area Mined by the AES Machine. Final Technical Report.  

National Technical Information Service (NTIS)

This report presents the results of an in-depth geotechnical investigation aimed at assessing the roof, floor, and coal pillar conditions in the area mined by an experimental Automatic Extraction System (AES), built by National Mine Service Co. The study ...

D. A. Newman F. Rafia Z. T. Bieniawski

1980-01-01

162

Solar heating shingle roof structure  

SciTech Connect

A solar heating roof shingle roof structure which combines the functions of a roof and a fluid conducting solar heating panel. Each shingle is a hollow body of the general size and configuration of a conventional shingle, and is provided with a fluid inlet and a fluid outlet. Shingles are assembled in a normal overlapping array to cover a roof structure, with interconnections between the inlets and outlets of successive shingles to provide a fluid path through the complete array. An inlet manifold is contained in a cap used at the peak of the roof and an outlet manifold is connected to the lowest row of shingles.

Straza, G.T.

1984-01-31

163

Effect of orientation and slope on hygrothermal behavior of roof assembled with selected components  

Microsoft Academic Search

Effect of orientation and slope on hygrothermal behavior of roof assembled with selected components on its hygrothermal response was investigated using a common software tool. Simulations were performed for eight types of roof facing four principle directions, north, east, south and west. The slope of roof varied by step of 15° from 15 to 45. The hygrothermal response was simulated

N. Pratinthong; D. Quenard; J. Khedari; L. Elegant

2005-01-01

164

Thermal performance of concrete masonry unit wall systems  

SciTech Connect

New materials, modern building wall technologies now available in the building marketplace, and unique, more accurate, methods of thermal analysis of wall systems create an opportunity to design and erect buildings where thermal envelopes that use masonry wall systems can be more efficient. Thermal performance of the six masonry wall systems is analyzed. Most existing masonry systems are modifications of technologies presented in this paper. Finite difference two-dimensional and three-dimensional computer modeling and unique methods of the clear wall and overall thermal analysis were used. In the design of thermally efficient masonry wall systems is t to know how effectively the insulation material is used and how the insulation shape and its location affect the wall thermal performance. Due to the incorrect shape of the insulation or structural components, hidden thermal shorts cause additional heat losses. In this study, the thermal analysis of the clear wall was enriched with the examination of the thermal properties of the wall details and the study of a quantity defined herein the Thermal Efficiency of the insulation material.

Kosny, J.

1995-12-31

165

Termiska prestanda foer solfangare: tre ars utomhusexponering av elva olika fabrikat (thermal performance of solar collectors: three years of outdoor exposure of eleven different products)  

SciTech Connect

Information on thermal performance of solar collectors subject to prolonged outdoor exposure has been lacking. Question is in which way changes caused by aging of materials affect thermal performance. Eleven different solar collectors were mounted on a roof for 3 years without circulating liquid, for which reason thermal stress accelerated their aging. They were subject to ocular inspection, and their degree of effectiveness was measured in solar simulator or outdoors. Components of interest in this context were: the covering disc, absorption surface, contact joint, if any, between absorption surface and pipes, insulation and casing. Relationship between condition of these components and some interesting solar collector parameters may give valuable information on influence of different defects on efficiency. Results of study show that efficiency is only somewhat lower than for corresponding new products.

Ekstroem, L.A.

1982-05-01

166

Thermal Performance of Urethane Foam Pipe Insulation At Cryogenic Temperatures  

Microsoft Academic Search

An analytical and experimental investigation of a two layer urethane foam cryogenic piping insulation system was conducted to deter mine the system's thermal performance. Significant natural convection was found to occur at the urethane foam seams and between the layers. Also, analytical techniques to model cryogenic piping insulation systems were developed. These results led to the development of a thermally

Dwight S. Musgrave

1979-01-01

167

Simulated performance of thermal storage in a solar cooker  

Microsoft Academic Search

An explicit finite-difference method is used to simulate the thermal performance of short-term thermal storage for a focusing, indoor, institutional, solar cooker. The cooker storage unit consists of a cylindrical solid block. The block is enclosed in a uniform layer of insulation except where there are cavities on the top and bottom surfaces to alllow heating of a pot from

P. Kariuki Nyahoro; Richard R. Johnson; John Edwards

1997-01-01

168

Dynamic Thermal Management for High-Performance Microprocessors  

Microsoft Academic Search

With the increasing clock rate and transistor count of to- day's microprocessors, power dissipation is becoming a critical component of system design complexity. Thermal and power-delivery issues are becoming especially critical for high-performance computing systems. In this work, we investigate dynamic thermal manage- ment as a technique to control CPU power dissipation. With the increasing usage of clock gating techniques,

David Brooks; Margaret Martonosi

2001-01-01

169

Thermal performance of an elliptical pin fin heat sink  

Microsoft Academic Search

Comparative thermal tests have been carried out using, aluminum heat sinks made with extruded fin, cross-cut rectangular pins, and elliptical shaped pins in low air flow environments. The elliptical pin heat sink was designed to minimize the pressure loss across the heat sink by reducing the vortex effects and to enhance the thermal performance by maintaining large exposed surface area

Christopher L. Chapman; Seri Lee; Bill L. Schmidt

1994-01-01

170

Mine roof bolt  

SciTech Connect

A mine roof bolt is described comprising: (a) a length of multi-strand cable defining a bolt shank; (b) a tapered plug comprising a body portion having an internal bore and a frusto-conical outer surface essentially concentric with said internal bore, said tapered plug being mounted about an end of said cable at said internal bore; and (c) an internally tapered drive collar having a frusto-conical inner surface that engages said frusto-conical outer surface of said tapered plug, and having an outer surface defining a drive head that accepts a driving mechanism for rotating and linearly translating said bolt, wherein said tapered plug is mounted on an end of said cable, and said drive collar is pressed down upon said tapered plug, forcing said tapered plug against said cable, such that said drive collar, said tapered plug, and said cable, when fitted tightly together, define said mine roof bolt.

Gillespie, H.D.

1993-07-27

171

A Monolithic Microconcentrator Receiver For A Hybrid PV-Thermal System: Preliminary Performance  

Microsoft Academic Search

An innovative hybrid PV-thermal microconcentrator (MCT) system is being jointly developed by Chromasun Inc., San Jose, California, and at the Centre for Sustainable Energy Systems, Australian National University. The MCT aims to develop the small-scale, roof-top market for grid-integrated linear CPV systems. A low profile, small footprint enclosure isolates system components from the environment, relaxing the demands on supporting structures,

D. Walter; V. Everett; M. Vivar; J. Harvey; R. van Scheppingen; S. Surve; J. Muric-Nesic; A. Blakers

2010-01-01

172

Mine roof supporting system  

SciTech Connect

A stabilizing arrangement for mine roof support systems of the type in which a series of support units, each including a transverse beam supported at opposite ends by extensible props, are interconnected by extensible struts in a manner to be selfadvancing by alternate retraction of support units from a roof supporting condition and extension of the struts to advance such retracted units relative to others of such units which are in an extended roof engaging condition. The connection of each prop to the beam in a given unit is pivotal to allow deflection of the beam and props of a supporting unit from a normal perpendicular relationship under load. The stabilizing means restores the props and beam to a normal perpendicular relationship for advancing movement of each support unit. The supporting units are further stabilized relative to the struts by prop supporting brackets permitting canting movement of the props from a perpendicular relationship with respect to the struts but maintaining the props in a generally upright position for unit advance.

Curry, P.F.

1981-06-23

173

Field study on the thermal environment of passive cooling system in RC building  

SciTech Connect

In recent years, various passive methods have come to be adopted in architecture design. The rooftop lawn is seen to have merit in the reduction in the air conditioning load of the building, as well as contributing to the mitigation of the heat island phenomenon. The roofs praying system is seen to be an effective method for the roof of low heat insulation performance, and can greatly reduce the heat load in the summer season. However, at present most of the buildings with an RC construction have the insulating material in the roof for providing thermal insulation in the winter season. There has been a trend to adopt the roof spraying system actively in even such a general RC building, but it is not clear how much actual effect it has. In this study, the authors conducted a measurement in an RC building with a rooftop spraying system and roof lawn in order to clarify the effects and problems on the thermal environment.

Zhou, Nan; Gao, Weijun; Nishida, Masaru; Kitayama, Hiroki; Ojima, Toshio

2004-10-30

174

Predicting the physiological performance of ectotherms in fluctuating thermal environments.  

PubMed

Physiological ecologists have long sought to understand the plasticity of organisms in environments that vary widely among years, seasons and even hours. This is now even more important because human-induced climate change is predicted to affect both the mean and variability of the thermal environment. Although environmental change occurs ubiquitously, relatively few researchers have studied the effects of fluctuating environments on the performance of developing organisms. Even fewer have tried to validate a framework for predicting performance in fluctuating environments. Here, we determined whether reaction norms based on performance at constant temperatures (18, 22, 26, 30 and 34°C) could be used to predict embryonic and larval performance of anurans at fluctuating temperatures (18-28°C and 18-34°C). Based on existing theory, we generated hypotheses about the effects of stress and acclimation on the predictability of performance in variable environments. Our empirical models poorly predicted the performance of striped marsh frogs (Limnodynastes peronii) at fluctuating temperatures, suggesting that extrapolation from studies conducted under artificial thermal conditions would lead to erroneous conclusions. During the majority of ontogenetic stages, growth and development in variable environments proceeded more rapidly than expected, suggesting that acute exposures to extreme temperatures enable greater performance than do chronic exposures. Consistent with theory, we predicted performance more accurately for the less variable thermal environment. Our results underscore the need to measure physiological performance under naturalistic thermal conditions when testing hypotheses about thermal plasticity or when parameterizing models of life-history evolution. PMID:22279077

Niehaus, Amanda C; Angilletta, Michael J; Sears, Michael W; Franklin, Craig E; Wilson, Robbie S

2012-02-15

175

Thermal mechanical performance test on suspended insulators for transmission line  

Microsoft Academic Search

This study described some basic performance tests and accelerated ageing test by cool-heat cycling methods and thermal mechanical performance test methods on alumina porcelain insulators (new and aged) used for transmission lines in Korea. There were no failures in electrical and mechanical performance tests such as high voltage strength, flashover voltage, impact strength, etc. in any of the samples. However

S. W. Han; H. G. Cho

2004-01-01

176

Cryogenic thermal distortion performance characterization for the JWST ISIM structure  

NASA Astrophysics Data System (ADS)

The James Webb Space Telescope (JWST) Integrated Science Instrument Module (ISIM) Structure is a precision optical metering structure for the JWST science instruments. Optomechanical performance requirements place stringent limits on the allowable thermal distortion of the metering structure between ambient and cryogenic operating temperature (~35 K). This paper focuses on thermal distortion testing and successful verification of performance requirements for the flight ISIM Structure. The ISIM Structure Cryoset Test was completed in Spring 2010 at NASA Goddard Space Flight Center in the Space Environment Simulator Chamber. During the test, the ISIM Structure was thermal cycled twice between ambient and cryogenic (~35 K) temperatures. Photogrammetry was used to measure the Structure in the ambient and cryogenic states for each cycle to assess both cooldown thermal distortion and repeatability. This paper will provide details on the post-processing of the metrology datasets completed to compare measurements with performance requirements.

Johnston, John; Cofie, Emmanuel; Hylan, Jason; Ohl, Raymond; Nowak, Maria; McGuffey, Douglas; Pontius, James; Johnson, Eric

2011-09-01

177

Development of thermal performance criteria for residential passive solar buildings  

SciTech Connect

In support of the development of thermal performance criteria for residential passive solar buildings, thermal design characteristics and anticipated performance for 266 projects in the HUD Passive Residential Design Competition and the HUD Cycle 5 Demonstration Program were analyzed. These passive residences are located in all regions of the United States requiring space heating, and they represent a variety of passive solar system types including direct gain, indirect gain, and solarium (isolated gain) systems. The results of this statistical analysis are being used to develop proposed minimum acceptable levels of thermal performance for passive solar buildings for the residential performance criteria. A number of performance measures were examined, including net solar contribution, solar fraction, and auxiliary energy use. These and other design and climate-related parameters were statistically correlated using the DATAPLOT computer program and standard statistical analysis techniques.

Sabatiuk, P.A. (Mueller Associates, Baltimore, MD); Cassel, D.E.; McCabe, M.; Scarbrough, C.

1980-01-01

178

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

SciTech Connect

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

Syd S. Peng

2005-01-15

179

Thermal performance of steel-framed walls. Final report  

SciTech Connect

In wall construction, highly conductive members spaced along the wall, which allow higher heat transfer than that through less conductive areas, are referred to as thermal bridges. Thermal bridges in walls tend to increase heat loss and, under certain adverse conditions, can cause dust streaking (``ghosting``) on interior walls over studs due to temperature differentials, as well as condensation in and on walls. Although such adverse conditions can be easily avoided by proper thermal design of wall systems, these effects have not been well understood and thermal data has been lacking. Therefore, the present study was initiated to provide (1) a better understanding of the thermal behavior of steel-framed walls, (2) a set of R-values for typical wall constructions, and (3) information that could be used to develop improved methods of predicting R-values. An improved method for estimating R-value would allow an equitable comparison of thermal performance with other construction types and materials. This would increase the number of alternative materials for walls available to designers, thus allowing them to choose the optimum choice for construction. Twenty-three wall samples were tested in a calibrated hot box (ASTM C9761) to measure the thermal performance of steel-framed wall systems. The tests included an array of stud frame configurations, exterior sheathing and fiberglass batt insulations. Other studies have not included the use of insulating sheathing, which reduces the extent of the thermal bridges and improves total thermal performance. The purpose of the project was to provide measured R-values for commonly used steel-framed wall configurations and to improve R-value estimating methods. Test results were compared to R-value estimates using the parallel path method, the isothermal planes method and the ASHRAE Zone method. The comparison showed that the known procedures do not fully account for the three-dimensional effects created by steel framing in a wall.

Barbour, E. [NAHB Research Center, Inc., Upper Marlboro, MD (United States); Goodrow, J. [Holometrix, Inc., Bedford, MA (United States); Kosny, J.; Christian, J.E. [Oak Ridge National Lab., TN (United States)

1994-11-21

180

Entering the Roofing and Waterproofing Industry. Roofing Workbook and Tests.  

ERIC Educational Resources Information Center

This book is one of a series of 10 units of instruction for roofing apprenticeship classes in California. It covers the following 14 topics and provides tests for them: the nature of the roofing and waterproofing industry; the apprenticeship program; apprenticeship and the public schools; collective bargaining, wages, and benefits; safety in the…

California State Dept. of Education, Sacramento. Bureau of Publications.

181

Entering the Roofing and Waterproofing Industry. Roofing Workbook and Tests.  

ERIC Educational Resources Information Center

|This book is one of a series of 10 units of instruction for roofing apprenticeship classes in California. It covers the following 14 topics and provides tests for them: the nature of the roofing and waterproofing industry; the apprenticeship program; apprenticeship and the public schools; collective bargaining, wages, and benefits; safety in the…

California State Dept. of Education, Sacramento. Bureau of Publications.

182

12. CENTRAL ROOF TRUSS AND ROOF SUPPORT BEAMS OF SARATOGA ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. CENTRAL ROOF TRUSS AND ROOF SUPPORT BEAMS OF SARATOGA GAS LIGHT COMPANY GASHOLDER NO. 2 HOUSE, LOOKING WEST. THE WIRES AND BEAM AT RIGHT OF PHOTOGRAPH HAVE BEEN ADDED TO STABILIZE TRUSS SYSTEM. - Saratoga Gas Light Company, Gasholder No. 2, Niagara Mohawk Power Corporation Substation Facility, intersection of Excelsior & East Avenues, Saratoga Springs, Saratoga County, NY

183

13. ONE OF TWO LATERAL ROOF TRUSSES AND ROOF SUPPORT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. ONE OF TWO LATERAL ROOF TRUSSES AND ROOF SUPPORT BEAMS OF SARATOGA GAS LIGHT COMPANY GASHOLDER NO. 2 HOUSE LOOKING WEST. THE WIRES AND BEAM AT RIGHT CENTER OF PHOTOGRAPH HAVE BEEN ADDED TO STABILIZE TRUSS SYSTEM - Saratoga Gas Light Company, Gasholder No. 2, Niagara Mohawk Power Corporation Substation Facility, intersection of Excelsior & East Avenues, Saratoga Springs, Saratoga County, NY

184

Enhancement of thermal performance in a sintered miniature heat pipe  

Microsoft Academic Search

The performance of a sintered miniature heat pipe is enhanced. With the capillary limitation, porosity takes priority over the wick structure parameters that would affect the heat transfer capacity. Since sintered dendritic copper powder has higher porosity, it is used to mix with pore former (Na2CO3) in experiments for increasing porosity, and hence enhancing the thermal performance. The results show

2005-01-01

185

Italsat thermal control: The in-orbit performances  

Microsoft Academic Search

Italsat F1 is a three axes stabilized communication satellite. The Italsat system consists of a global beam and a multibeam package (20\\/30 GHz) for domestic communication services and an experimental propagation package at 40\\/50 GHz with European coverage. The spacecraft thermal control design was experimentally qualified by means of a solar simulation test performed on a dedicated structural and thermal

Marco Giommi; Stefano Liverani; Enrico Sacchi

1991-01-01

186

Respirator performance for STEL exposures in thermal environments  

Microsoft Academic Search

An irritant smoke qualitative field test procedure was developed and used to evaluate the performance of rubber and silicone facepiece models of a half-mask air-purifying respirator under thermal and non-thermal working conditions for 37 maintenance workers at a coal-fired, electrical power generation plant. Prior to participating in field testing, subjects were screened using an irritant smoke qualitative fit test. During

Visage

1987-01-01

187

Droplet ejection performance of a monolithic thermal inkjet print head  

NASA Astrophysics Data System (ADS)

This paper presents a simulation study of the droplet ejection performance of a thermal inkjet print head. The geometry of the print head comprises a dome-shaped ink chamber, a nozzle guide and a ring-shaped heater integrated on each chamber. The design eliminates direct contact between the heater and the ink, thus minimizing heater burnout. The ink manifold, ink chamber and nozzle are aligned, thus facilitating higher nozzle density. The model simulates thermal bubble dynamics including nucleation and growth of thermal bubbles caused by a thermal pulse. The model was validated by comparing model predictions with experimental results for a previously reported print head design. Then, the model was used to simulate the droplet ejection performance of the proposed inkjet print head. Effects of print head geometry including nozzle diameter, nozzle length, chamber size, heater dimensions and location, thermal conductivity of the passivation layer, operating conditions including total thermal energy and pulse width, properties of the ink including density, viscosity and surface tension on the performance of the inkjet device are investigated. The influence of these parameters on the drop volume and velocity, threshold energy and tail length of the ejected droplets is studied.

Sen, A. K.; Darabi, J.

2007-08-01

188

Roof control system  

SciTech Connect

Roof control system for underground strata is described, comprising: (a) an elongated bolt adapted for insertion into a hole bored in underground strata; (b) anchor means for securely anchoring the bolt in the hole at a location where a significant length of the bolt remains between the opening of the borehole and the anchor means; (c) tension means for placing said significant length of said bolt in tension by rotating the bolt at a predetermined torque, the torque means including a plate mounted on the bolt and located adjacent to the outer surface of the strata, and a nut means on the end of the bolt for engaging the plate; (d) tension/torque adjustment means for selectively adjusting friction between adjacent surfaces which rub against each other when the bolt is rotated, whereby the tension/torque ratio of the bolt is selected to match the desired level for a particular type of underground strata, the tension/torque adjustment means including an array of friction reducing washers with different contact surface areas, for location between the nut means and plate. A method of mine control for underground strata is also described using this roof bolt.

Stankus, J.C.

1993-08-03

189

Roof drilling system  

SciTech Connect

A roof-drilling system for use in subterranean mining applications and the like in which the drill head of a roof drilling machine is arranged such that the receiving cavity of its chuck is configured having a lost motion association with the drive-in portion of starter and driver drill steel rods. The lower surface of a retainer fixed to the drill head and having a non-circular aperture formed therein serves to define one bearing surface for utilizing the drill head itself to pull the assemblage of drill steel from a completed bore. To remove the drill steel driver component from the drill head chuck, the miner grasps the lowermost portion and rotates it a relatively small amount, for example about 1/8 turn. To provide for interlocking of the various components of the drill steel, I.E. Driver component, extension components finishing rods and the like, the tip of the male ends of each component are formed having a shallow groove and each corresponding female socket is provided with a corresponding transversely oriented bore. Conventional wire or its' equivalent is inserted within the bore by the miner in the course of assembling the drill steel during a drilling operation.

McSweeney, L.H.

1980-10-07

190

ENVIRONMENTAL BENEFITS OF GREEN ROOFS  

Microsoft Academic Search

Although roof gardens are not new, as evidenced by the Hanging Gardens of Babylon (approx. 600 BC), their usage was not widely propagated in our modern buildings. While the aesthetics and beauty of a properly manicured roof garden can be easily appreciated, the environmental and ecological benefits are somewhat less well known. However, the Green Movement in the 60's has

Michael Wong

191

Earth covered vs. conventional roof  

Microsoft Academic Search

A significant reduction in construction costs of underground houses is possible by using steel joists for the roof system. By reducing the earth covering to 6-8 inches the structural support members required are smaller and less expensive. The roof described has an R factor of 79.2. (JMT)

Woodrum

1982-01-01

192

How Cool Is Your Roof?  

ERIC Educational Resources Information Center

|Explains a concept called cool roof that is used to reduce electricity costs for air conditioning, and also reduce the price of air conditioning units. Discusses the light reflecting capabilities of metal roofing as well as coatings that can stop leaks. (GR)|

Fickes, Michael

2001-01-01

193

Wind Loads on Canopy Roofs.  

National Technical Information Service (NTIS)

Wind pressure distributions on 30 m x 30 m canopy roofs over a range of roof pitch angles were determined in the wind tunnel, in a simulated, terrain category 3 (AS-1170) atmospheric boundary layer flow at a length scale of 1 / 100. Contour plots of local...

J. D. Ginger C. W. Letchford

1991-01-01

194

How Cool Is Your Roof?  

ERIC Educational Resources Information Center

Explains a concept called cool roof that is used to reduce electricity costs for air conditioning, and also reduce the price of air conditioning units. Discusses the light reflecting capabilities of metal roofing as well as coatings that can stop leaks. (GR)

Fickes, Michael

2001-01-01

195

Measuring mine roof bolt strains  

DOEpatents

A mine roof bolt and a method of measuring the strain in mine roof bolts of this type are disclosed. According to the method, a flat portion on the head of the mine roof bolt is first machined. Next, a hole is drilled radially through the bolt at a predetermined distance from the bolt head. After installation of the mine roof bolt and loading, the strain of the mine roof bolt is measured by generating an ultrasonic pulse at the flat portion. The time of travel of the ultrasonic pulse reflected from the hole is measured. This time of travel is a function of the distance from the flat portion to the hole and increases as the bolt is loaded. Consequently, the time measurement is correlated to the strain in the bolt. Compensation for various factors affecting the travel time are also provided.

Steblay, Bernard J. (Lakewood, CO)

1986-01-01

196

Solar heating shingle roof structure  

SciTech Connect

A solar heating roof shingle roof structure which combines the functions of a roof and a fluid conducting solar heating panel. Each shingle is a hollow body of the general size and configuration of a conventional shingle, and is provided with a fluid inlet socket at the upper end and a fluid outlet plug at the lower end with a skirt at the lower end overlapping the plug. Shingles are assembled in an overlapping array to cover a roof structure, with interconnections between the inlets and outlets of successive longitudinally positioned shingles to provide fluid paths through the complete array. An inlet manifold is positioned at the upper end of the array or in the alternative contained in a cap used at the peak of the roof and an outlet manifold is connected to the outlet of the lowest row of shingles.

Straza, G.T.

1981-01-13

197

Translucent phase change material thermal storage system  

Microsoft Academic Search

A new, modular, phase-change-material thermal storage system developed for use behind south-facing windows and roofs in passive or simple active applications is described. The translucent phase change material and container have a unique ability to provide compact thermal storage while transmitting and controlling natural daylignt within almost any new or existing building. Performance of the Thermal Energy Storage Pod System

Sedrick

1980-01-01

198

Duct thermal performance models for large commercial buildings  

SciTech Connect

Despite the potential for significant energy savings by reducing duct leakage or other thermal losses from duct systems in large commercial buildings, California Title 24 has no provisions to credit energy-efficient duct systems in these buildings. A substantial reason is the lack of readily available simulation tools to demonstrate the energy-saving benefits associated with efficient duct systems in large commercial buildings. The overall goal of the Efficient Distribution Systems (EDS) project within the PIER High Performance Commercial Building Systems Program is to bridge the gaps in current duct thermal performance modeling capabilities, and to expand our understanding of duct thermal performance in California large commercial buildings. As steps toward this goal, our strategy in the EDS project involves two parts: (1) developing a whole-building energy simulation approach for analyzing duct thermal performance in large commercial buildings, and (2) using the tool to identify the energy impacts of duct leakage in California large commercial buildings, in support of future recommendations to address duct performance in the Title 24 Energy Efficiency Standards for Nonresidential Buildings. The specific technical objectives for the EDS project were to: (1) Identify a near-term whole-building energy simulation approach that can be used in the impacts analysis task of this project (see Objective 3), with little or no modification. A secondary objective is to recommend how to proceed with long-term development of an improved compliance tool for Title 24 that addresses duct thermal performance. (2) Develop an Alternative Calculation Method (ACM) change proposal to include a new metric for thermal distribution system efficiency in the reporting requirements for the 2005 Title 24 Standards. The metric will facilitate future comparisons of different system types using a common ''yardstick''. (3) Using the selected near-term simulation approach, assess the impacts of duct system improvements in California large commercial buildings, over a range of building vintages and climates. This assessment will provide a solid foundation for future efforts that address the energy efficiency of large commercial duct systems in Title 24. This report describes our work to address Objective 1, which includes a review of past modeling efforts related to duct thermal performance, and recommends near- and long-term modeling approaches for analyzing duct thermal performance in large commercial buildings.

Wray, Craig P.

2003-10-01

199

Thermal Performance of a Functionally Graded Radial Fin  

NASA Astrophysics Data System (ADS)

This paper investigates the steady-state thermal performance of a radial fin of rectangular profile made of a functionally graded material. The thermal conductivity of the fin varies continuously in the radial direction following a power law. The boundary conditions of a constant base temperature and an insulated tip are assumed. Analytical solutions for the temperature distribution, heat transfer rate, fin efficiency, and fin effectiveness are found in terms of Airy wave functions, modified Bessel functions, hyperbolic functions, or power functions depending on the exponent of the power law. Numerical results illustrating the effect of the radial dependence of the thermal conductivity on the performance of the fin are presented and discussed. It is found that the heat transfer rate, the fin efficiency, and the fin effectiveness are highest when the thermal conductivity of the fin varies inversely with the square of the radius. These quantities, however, decrease as the exponent of the power law increases. The results of the exact solutions are compared with a solution derived by using a spatially averaged thermal conductivity. Because large errors can occur in some cases, the use of a spatially averaged thermal-conductivity model is not recommended.

Aziz, A.; Rahman, M. M.

2009-10-01

200

Building roof with conical holes containing PCM to reduce the cooling load: Numerical study  

Microsoft Academic Search

The thermal effectiveness of a building’s roof with phase change material (PCM) is presented in this paper. The considered model consists of a concrete slab with vertical cone frustum holes filled with PCM. The objective of incorporating the PCM into the roof structure is to utilize its high latent heat of fusion to reduce the heat gain during the energy

Esam M. Alawadhi; Hashem J. Alqallaf

2011-01-01

201

Demonstration of Cooling Savings of Light Colored Roof Surfacing in Florida Commercial Buildings: Our Savior's School.  

ERIC Educational Resources Information Center

|A 2-year Florida study attempted to quantify air conditioning cost savings when buildings have a white reflective roof. A 10,000 square foot elementary school with a gray modified bitumen roof over plywood decking that had a solar reflectance of 23 percent was monitored for an entire year. After one year of building thermal conditions and…

Parker, Danny S.; Sherwin, John R.; Sonne, Jeffrey K.; Barkaszi, Stephen F., Jr.

202

Demonstration of Cooling Savings of Light Colored Roof Surfacing in Florida Commercial Buildings: Our Savior's School.  

ERIC Educational Resources Information Center

A 2-year Florida study attempted to quantify air conditioning cost savings when buildings have a white reflective roof. A 10,000 square foot elementary school with a gray modified bitumen roof over plywood decking that had a solar reflectance of 23 percent was monitored for an entire year. After one year of building thermal conditions and…

Parker, Danny S.; Sherwin, John R.; Sonne, Jeffrey K.; Barkaszi, Stephen F., Jr.

203

An investigation of sensible heat fluxes at a green roof in a laboratory setup  

Microsoft Academic Search

During the last few years, several models have been proposed for the calculation of green roof thermal behavior, but the validation studies of such models are lacking a comprehensive set of highly accurate data. In this study, an experimental laboratory setup was used to create different environmental conditions and to measure sensible heat fluxes to\\/from a vegetated roof assembly. This

Tahir Ayata; Paulo Cesar Tabares-Velasco; Jelena Srebric

2011-01-01

204

Thermal performance modeling of NASA s scientific balloons  

NASA Astrophysics Data System (ADS)

The flight performance of a scientific balloon is highly dependant on the interaction between the balloon and its environment. The balloon is a thermal vehicle. Modeling a scientific balloon's thermal performance has proven to be a difficult analytical task. Most previous thermal models have attempted these analyses by using either a bulk thermal model approach, or by simplified representations of the balloon. These approaches to date have provided reasonable, but not very accurate results. Improvements have been made in recent years using thermal analysis tools developed for the thermal modeling of spacecraft and other sophisticated heat transfer problems. These tools, which now allow for accurate modeling of highly transmissive materials, have been applied to the thermal analysis of NASA's scientific balloons. A research effort has been started that utilizes the "Thermal Desktop" addition to AUTO CAD. This paper will discuss the development of thermal models for both conventional and Ultra Long Duration super-pressure balloons. This research effort has focused on incremental analysis stages of development to assess the accuracy of the tool and the required model resolution to produce usable data. The first stage balloon thermal analyses started with simple spherical balloon models with a limited number of nodes, and expanded the number of nodes to determine required model resolution. These models were then modified to include additional details such as load tapes. The second stage analyses looked at natural shaped Zero Pressure balloons. Load tapes were then added to these shapes, again with the goal of determining the required modeling accuracy by varying the number of gores. The third stage, following the same steps as the Zero Pressure balloon efforts, was directed at modeling super-pressure pumpkin shaped balloons. The results were then used to develop analysis guidelines and an approach for modeling balloons for both simple first order estimates and detailed full models. The development of the radiative environment and program input files, the development of the modeling techniques for balloons, and the development of appropriate data output handling techniques for both the raw data and data plots will be discussed. A general guideline to match predicted balloon performance with known flight data will also be presented. One long-term goal of this effort is to develop simplified approaches and techniques to include results in performance codes being developed.

Franco, H.; Cathey, H.

205

Performance of thermal conductivity probes for planetary applications  

NASA Astrophysics Data System (ADS)

This work aims to contribute to the development of in situ instruments feasible for space application. Commercial as well as custom made thermal sensors, based on the transient hot wire technique and suitable for direct measurement of the effective thermal conductivity of granular media, were tested for application under airless conditions. The investigated media range from compact specimen of well known thermal conductivity used for calibration of the sensors to various granular planetary analogue materials of different shape and grain size. Measurements were performed under gas pressures ranging from 103 hPa down to about 10-5 hPa. It was found that for the inspected granular materials the given pressure decrease results in a decrease of the thermal conductivity by about two orders of magnitude. In order to check the ability of custom-made sensors to measure the thermal conductivity of planetary surface layers, detailed numerical simulations predicting the response of the different sensors have also been performed. Both, measurements and simulations, revealed that for investigations under high vacuum conditions (as they prevail e.g. on the lunar surface) the derived thermal conductivity values can significantly depend on the sensor geometry, the axial heat flow and the thermal contact between probe and surrounding material. Therefore in these cases a careful calibration of each particular sensor is necessary in order to obtain reliable thermal conductivity measurements. The custom-made sensors presented in this work can serve as prototypes for payload to be flown on future planetary lander missions, in particular for airless bodies like the Moon, asteroids and comets, but also for Mars.

Hütter, E. S.; Kömle, N. I.

2012-01-01

206

Can wet roof insulation be dried out  

SciTech Connect

Nondestructive techniques are being widely used to locate wet insulation in compact roofing systems. Now that wet insulation can be found, breather vents and so called ''breathable'' membranes are being promoted to dry out wet insulation, thereby recovering its thermal effectiveness. Exposure tests in New Hampshire indicate that the above venting methods are all rather ineffective in drying sealed specimens of perlite and fibrous glass roof insulation. It would take many decades to dry specimens at the rates measured over the past two years. Cross-ventilation within the insulation increased the rate of drying. For perlite insulation, the faster rate would still result in a drying time measured in decades. For fibrous glass insulation, the drying time was reduced to 13 years. The authors have succeeded in drying fibrous glass insulation in a roof by removing the water with a vacuum cleaner. In a series of tests with a total duration of 134 h, about 0.42 m/sup 3/ (110 gal) of water was removed from a 17-m/sup 2/ (180-ft/sup 2/) area of 38-mm (1.5-in.)-thick insulation. Before the water was removed the insulation had only 21 percent of its dry insulating ability; afterward it had 83 percent.

Tobiasson, W.; Coutermarsh, B.; Greatorex, A.; Korhonen, C.

1981-12-01

207

Can wet roof insulation be dried out  

SciTech Connect

Nondestructive techniques are being widely used to locate wet insulation in compact roofing systems. Now that wet insulation can be found, breather vents and so-called breathable membranes are being promoted to dry out wet insulation, thereby recovering its thermal effectiveness. Exposure tests in New Hampshire indicate that the above venting methods are all rather ineffective in drying sealed specimens of perlite and fibrous glass roof insulation. It would take many decades to dry our specimens at the rates measured over the past two years. Cross-ventilation within the insulation increased the rate of drying. For perlite insulation, the faster rate would still result in a drying time measured in decades. For fibrous glass insulation, the drying time was reduced to 13 years. Fibrous glass insulation in a roof was dried by removing the water with a vacuum cleaner. In a series of tests with a total duration of 134 h, about 0.4 2 m/sup 3/ (110 gal) of water was removed from a 17-m/sup 2/ (180-ft/sup 2/) area of 38-mm (1.5-in.)-thick insulation. Before the water was removed the insulation had only 21% of its dry insulating ability; afterward it had 83%.

Tobiasson, W.; Korhonen, C.; Coutermarsh, B.; Greatorex, A.

1983-01-01

208

THERMAL AND ELECTRICAL PERFORMANCES OF A NEW KIND AIR COOLED PHOTOVOLTAIC THERMAL SYSTEM FOR BUILDING APPLICATION  

Microsoft Academic Search

In this paper, a simulation model has been presented for the modeling of thermal and electrical performances of an air cooled photovoltaic\\/thermal (PV\\/T) system. Based on the detailed energy balances of various components of the system, a new type (TYPE250) has been developed in FORTRAN for its integration with the TRNSYS software. The usefulness of developed model has been shown

R. S. Adhikari; F. Butera; P. Caputo; P. Oliaro; N. Aste

209

AUTOMATIC 3D BUILDING RECONSTRUCTION USING PLANE-ROOF STRUCTURES  

Microsoft Academic Search

This paper introduces a new method for automatic 3D building reconstruction using plane-roof structures. A boundary representation (b-rep) of a coarse building hypothesis is constructed in a bottom-up approach from simple geometric primitives in image domain to more complex geometric primitives (roof structure) in object domain. Subsequently, a hypothesis model verification is performed in a top-down approach by back projecting

Babak Ameri; Dieter Fritsch

2000-01-01

210

Thermal performances investigation of a wet cooling tower  

Microsoft Academic Search

This paper presents an experimental investigation of the thermal performances of a forced draft counter flow wet cooling tower filled with an “VGA” (Vertical Grid Apparatus) type packing. The packing is 0.42m high and consists of four (04) galvanised sheets having a zigzag form, between which are disposed three (03) metallic vertical grids in parallel with a cross sectional test

M. Lemouari; M. Boumaza; I. M. Mujtaba

2007-01-01

211

Influence of thermal properties on friction performance of carbon composites  

Microsoft Academic Search

Three different needled felt C\\/C composites containing from 5 to 25% fiber oriented normal to the friction surface (z-fiber) were evaluated and tested for friction performance. A laboratory dynamometer was used to simulate cold taxi, hot taxi and normal landing braking events utilizing a single stator and rotor pair. Temperatures measured near the friction surface were lowest for highest thermal

Christopher Byrne; Zhiyuan Wang

2001-01-01

212

Development of ball grid array packages with improved thermal performance  

Microsoft Academic Search

To provide electronics packages with sufficient cooling during applications to secure improved reliability and performance of the packages has been one of the challenging tasks for their manufacturers and end users. Since the introduction of the standard ball grid array (BGA) package, continued efforts by package developers have successively resulted in a family of thermally enhanced BGA packages. The extra

Y. Y. Ma; Desmond Y. R. Chong; C. K. Wang; Anthony Y. S. Sun

2005-01-01

213

Thermal performance of horizontal closed-loop oscillating heat pipes  

Microsoft Academic Search

This research aims to experimentally investigate the thermal performance of a horizontal closed-loop oscillating heat pipe (HCLOHP) at normal operating condition. The tested HCLOHPs were made of copper capillary tubes with various inner diameters, evaporator lengths and number of turns. The working fluids used within the HCLOHPs were distilled water and absolute ethanol, which were added into the tubes to

Piyanun Charoensawan; Pradit Terdtoon

2007-01-01

214

Thermal performance analysis on unit tube for heat pipe receiver  

Microsoft Academic Search

To reduce the mass and improve the thermal performance of the heat receiver, a heat pipe receiver was researched for the space solar dynamic power system. Corresponding mathematical and physical models were built, and a method was devised to provide a numerical equation by which the temperature of the containment canister outer wall, heat pipe wall temperature, working fluid exit

Haiting Cui; Zhenhui Wang; Yanshu Guo; Weiqiang Xu; Xiugan Yuan

2006-01-01

215

Thermal performance of horizontal closed-loop oscillating heat pipes  

Microsoft Academic Search

This research aims to experimentally investigate the thermal performance of a horizontal closed-loop oscillating heat pipe (HCLOHP) at normal operating condition. The tested HCLOHPs were made of copper capillary tubes with various inner diameters, evaporator lengths and number of turns. The working fluids used within the HCLOHPs were distilled water and absolute ethanol, which were added into the tubes to

Piyanun Charoensawan; Pradit Terdtoon

2008-01-01

216

Performance of a cylindrical phase change thermal energy storage unit  

Microsoft Academic Search

The high-temperature performance of a eutectic salt Phase Change Material (PCM) in a cylindrical Thermal Energy Storage Container (TESC) sample is evaluated by means of an experimental apparatus with a water-circulated calorimeter. The phase change characteristics of the salt during melting and solidification were observed by monitoring the external axial temperature profile of the container, and the analysis of the

R. Ponnappan; D. L. Jacobson

1982-01-01

217

Thermal Performance of a Customized Multilayer Insulation (MLI).  

National Technical Information Service (NTIS)

The thermal performance of a LH2 tank on a shroudless vehicle was investigated. The 1.52 m (60 in) tank was insulated with 2 MLI blankets consisting of 18 double aluminized Mylar radiation shields and 19 silk net spacers. The temperature of outer space wa...

K. E. Leonhard

1976-01-01

218

Thermal performance of a customized multilayer insulation (MLI)  

Microsoft Academic Search

The thermal performance of a LH2 tank on a shroudless vehicle was investigated. The 1.52 m (60 in) tank was insulated with 2 MLI blankets consisting of 18 double aluminized Mylar radiation shields and 19 silk net spacers. The temperature of outer space was simulated by using a cryoshroud which was maintained at near liquid hydrogen temperature. The heating effects

K. E. Leonhard

1976-01-01

219

Evaluating the Performance of Building Thermal Mass Control Strategies  

Microsoft Academic Search

A tool was developed that allows evaluation of thermal mass control strategies using HVAC utility costs as the baseline for comparison. Inverse models are used to represent the behavior of the building, cooling plant, and air distribution system. Inverse models use measured data to “learn” system behavior and provide relatively accurate site-specific performance predictions. Based on weather and solar inputs,

James E. Braun; Kent W. Montgomery; Nitin Chaturvedi

2001-01-01

220

Polymer gear surface thermal wear and its performance prediction  

Microsoft Academic Search

This paper will concentrate on acetal gear wear behaviour and its performance prediction based on the extensive investigations on the gear thermal mechanical contact both experimentally and numerically. It has been found from the tests that acetal gear wear rate will be increased dramatically when the load reaches a critical value for a specific geometry and running speed. The gear

K. Mao; W. Li; C. J. Hooke; D. Walton

2010-01-01

221

Performance of thermal conductivity probes for planetary applications  

NASA Astrophysics Data System (ADS)

This work aims to contribute to the development of in situ instruments feasible for space application. Commercial as well as custom-made thermal sensors, based on the transient hot wire technique and suitable for direct measurement of the effective thermal conductivity of granular media, were tested for application under airless conditions. In order to check the ability of custom-made sensors to measure the thermal conductivity of planetary surface layers, detailed numerical simulations predicting the response of the different sensors have been performed. These simulations reveal that for investigations under high vacuum conditions (as they prevail, e.g. on the lunar surface), the derived thermal conductivity values can significantly depend on sensor geometry, axial heat flow, and the thermal contact between probe and surrounding material. Therefore, a careful calibration of each particular sensor is necessary in order to obtain reliable thermal conductivity measurements. The custom-made sensors presented in this work can serve as prototypes for payload to be flown on future planetary lander missions, in particular for airless bodies like the Moon, asteroids and comets, but also for Mars.

Hütter, E. S.; Kömle, N. I.

2012-05-01

222

Testing the thermal performance of uncovered solar collectors  

SciTech Connect

A proposal for an international standard, To Determine the Thermal Performance of Uncovered Collectors,' is presented. Test particulars as the measurement of the longware radiation and the characterization of the wind field determining the convective losses of the absorber surface are discussed, both for indoor and outdoor conditions. The model includes testing under unsteady conditions. A comparison with alternate test approaches is performed. Experimental results are presented.

Soltau, H. (Ludwig-Maximilians-Univ., Muenchen (Germany))

1992-10-01

223

Performance Study of a Thermal-Envelope House: Phase II. Cooling Performance. Final Report.  

National Technical Information Service (NTIS)

The thermal envelope house is shown to perform much better than conventional houses without mechanical refrigeration and better than one would expect from most passively cooled houses in the hot-humid climate of Georgia. Peak temperatures inside the house...

J. M. Akridge C. C. Benton

1981-01-01

224

Architectural designs and thermal performances of school sports-halls  

Microsoft Academic Search

The school playground is an essential part of any school building because of its important role in the overall teaching process. The study presents the current design of most of the governmental school playgrounds in Cairo and shows how existing playgrounds sustain this function and describes the inherent shortcomings of that design. Constructing a sports hall on the roof of

Abd El-Wahab M. Adel El-Kadi; Mona A. Fanny

2003-01-01

225

Thermal performance of a geofluid direct-contact heat exchanger  

SciTech Connect

A sieve-tray direct-contact heat exchanger was used to transfer heat from a 280/sup 0/F geothermal fluid to the working fluid, isobutane, in the Raft River 60kW prototype plant. A series of experiments were run at different working fluid-to-geofluid flow ratios which produced different boiling conditions. In this paper, the results of these experiments are analyzed on the basis of thermal performance. The flow ratio, the geofluid outlet temperature, the working fluid inlet temperature, the amount of working fluid dissolved or entrained in geofluid, and tray efficiency are varied and preheating temperature profiles are calculated. These are compared with the experimentally obtained temperature profiles and the relative effects of the variables are evaluated. From this, it was determined that the approach temperature difference was on the order of .1/sup 0/ after 17 preheating trays, and the tray efficiencies, which appear to be about the same for all trays, reached approx. 70%. It was also determined that entrainment has a negligible effect on column thermal performance. The thermal performance of this column compares favorably with a spray-tower direct-contact heat exchanger and a shell-and-tube heat exchanger in terms of overall heat-transfer coefficient. Distributor tray and boiling tray behavior are discussed. These is some discussion of operations and thermal hydraulics as well.

Wiggins, D.J.; Mines, G.L.; Wahl, E.

1983-01-01

226

Performance penalties caused by thermal coupling in solar piping loops  

SciTech Connect

Solar heating systems often employ conduits to carry cool fluid to the collector array and to carry the heated fluid back to the storage tank. In systems in which these two conduits are bundled together in one cover (in what has come to be known as the `life-line`) there is a thermal performance penalty caused by heat transfer from the hot conduit to the cold conduit. This cross heat transfer results in a penalty in system performance, and this paper is about evaluating this penalty. We show that the standard Hottel-Whillier-Bliss (HWB) equation can be modified to simultaneously take into account both the pipe heat losses to the ambient environment and the cross heat transfer between the hot and cold streams. Parameters in these equations are the thermal resistances between the fluids and between each fluid and the ambient. Methods are presented for both calculating and measuring these thermal resistances. We carry out sample calculations of the parameters in the modified HWB equation for a representative solar DHW system equipped with either of two different life-lines of commercial design. System simulations using these parameters reveal that the thermal effects of these life-lines are to reduce the net delivered solar energy by 6-14%, and that heat loss to ambient is more detrimental to the system performance than heat transfer from the hot to the cold conduit. 8 refs., 4 figs., 2 tabs.

Brunger, A.P.; Hollands, K.G.T.; Anthony, M.A.; Zielonko, D.; Liang, C. [Univ. of Waterloo (Canada)

1996-10-01

227

Computational Analysis on Performance of Thermal Energy Storage (TES) Diffuser  

NASA Astrophysics Data System (ADS)

Application of thermal energy storage (TES) system reduces cost and energy consumption. The performance of the overall operation is affected by diffuser design. In this study, computational analysis is used to determine the thermocline thickness. Three dimensional simulations with different tank height-to-diameter ratio (HD), diffuser opening and the effect of difference number of diffuser holes are investigated. Medium HD tanks simulations with double ring octagonal diffuser show good thermocline behavior and clear distinction between warm and cold water. The result show, the best performance of thermocline thickness during 50% time charging occur in medium tank with height-to-diameter ratio of 4.0 and double ring octagonal diffuser with 48 holes (9mm opening ~ 60%) acceptable compared to diffuser with 6mm ~ 40% and 12mm ~ 80% opening. The conclusion is computational analysis method are very useful in the study on performance of thermal energy storage (TES).

Adib, M. A. H. M.; Adnan, F.; Ismail, A. R.; Kardigama, K.; Salaam, H. A.; Ahmad, Z.; Johari, N. H.; Anuar, Z.; Azmi, N. S. N.

2012-09-01

228

Study on evaporative cooling effect of roof lawn gardens  

Microsoft Academic Search

In a very hot climate equivalent to a Japanese summer, the reduction of heat coming into rooms is very important with respect to thermal comfort and energy efficiency. The objective of this study is to investigate the evaporative cooling effect from roof lawn gardens planted in non-woven fabric as one mode of passive cooling. It was confirmed by field measurements

S Onmura; M Matsumoto; S Hokoi

2001-01-01

229

Analysis of Wind Forces on RoofTop Solar Panel  

Microsoft Academic Search

Structural loads on solar panels include forces due to high wind, gravity, thermal expansion, and earthquakes. International Building Code (IBC) and the American Society of Civil Engineers are two commonly used approaches in solar industries to address wind loads. Minimum Design Loads for Buildings and Other Structures (ASCE 7-02) can be used to calculate wind uplift loads on roof-mounted solar

Yogendra Panta; Ganesh Kudav

2011-01-01

230

Measured energy savings of light colored roofs: Results from three California demonstration sites  

SciTech Connect

Measured data and computer simulations have demonstrated the impact of roof albedo in reducing cooling energy use in buildings. Savings are a function of both climate and the amount of roof insulation. The cooling energy savings for reflective roofs are highest in hot climates. A reflective roof may also lead to higher heating energy use. Reflective coatings are also used in commercial buildings to protect the roofing membrane, and hence, maintain and prolong the useful life of the roof. Reflectivity of coatings changes with weathering and aging which in turn could have an effect on building cooling-energy savings. For that reason, reflective roof coatings are not primarily marketed for their energy savings potential. To monitor the field performance of reflective coatings, the authors initiated a demonstration project where three commercial buildings in California were painted with light-colored roof coatings. The buildings are two medical care centers and one drug store. At all sites, the roof reflectance, both fresh and aged, and cooling energy use were monitored. In addition, they measured temperature throughout the roof systems and inside the conditioned space. In the monitored buildings, increasing the roof reflectance from an initial value of about 20% to 60%, dropped the roof temperature on hot summer afternoons by about 45 F. Summertime standard-weekday average daily air-conditioning savings were 18% (198 kWh) in the first medical office building, 13% (86 kWh) in the second medical office building, and 2% (13 kWh) in the drug store. The overall u-value of the roofs had dictated the impact of roof reflectance.

Akbari, H.; Gartland, L.; Konopacki, S.

1998-06-01

231

IMPULSE---an advanced, high performance nuclear thermal propulsion system  

SciTech Connect

IMPULSE is an advanced nuclear propulsion engine for future space missions based on a novel conical fuel. Fuel assemblies are formed by stacking a series of truncated (U, Zr)C cones with non-fueled lips. Hydrogen flows radially inward between the cones to a central plenum connected to a high performance bell nozzle. The reference IMPULSE engine rated at 75,000 lb thrust and 1800 MWt weighs 1360 kg and is 3.65 meters in height and 81 cm in diameter. Specific impulse is estimated to be 1000 for a 15 minute life at full power. If longer life times are required, the operating temperature can be reduced with a concomitant decrease in specific impulse. Advantages of this concept include: well defined coolant paths without outlet flow restrictions; redundant orificing; very low thermal gradients and hence, thermal stresses, across the fuel elements; and reduced thermal stresses because of the truncated conical shape of the fuel elements.

Petrosky, L.J.; Disney, R.K.; Mangus, J.D. (Advanced Programs Department, Westinghouse Electric Corporation, P.O. Box 158, Madison, Pennsylvania 15663-0158 (United States)); Gunn, S.A.; Zweig, H.R. (Rocketdyne Division, Rockwell International Corporation, 6633 Canoga Avenue, P.O. Box 7922, Canoga Park, California 91309-7922 (United States))

1993-01-10

232

IMPULSE-an advanced, high performance nuclear thermal propulsion system  

NASA Astrophysics Data System (ADS)

IMPULSE is an advanced nuclear propulsion engine for future space missions based on a novel conical fuel. Fuel assemblies are formed by stacking a series of truncated (U, Zr)C cones with non-fueled lips. Hydrogen flows radially inward between the cones to a central plenum connected to a high performance bell nozzle. The reference IMPULSE engine rated at 75,000 lb thrust and 1800 MWt weighs 1360 kg and is 3.65 meters in height and 81 cm in diameter. Specific impulse is estimated to be 1000 for a 15 minute life at full power. If longer life times are required, the operating temperature can be reduced with a concomitant decrease in specific impulse. Advantages of this concept include: well defined coolant paths without outlet flow restrictions; redundant orificing; very low thermal gradients and hence, thermal stresses, across the fuel elements; and reduced thermal stresses because of the truncated conical shape of the fuel elements.

Petrosky, Lyman J.; Disney, R. Kep; Mangus, James D.; Gunn, Stanley A.; Zweig, Herbert R.

1993-01-01

233

Study on Thermal Performances of a Small Loop Heat Pipe  

NASA Astrophysics Data System (ADS)

This paper describes thermal performance of a small loop heat pipe device in an atmospheric condition. A comprehensive test program including start-up, power step up, power cycle and low power tests was performed. The effects of gravity on start-up and heat transport capability were also evaluated. An analytical model for the loop was developed to predict and evaluate the steady state operating performance. The test results demonstrated the robustness of the LHP. The analytical results showed good agreement with the test results except at the low power region. The feasibility of loop temperature control through compensation chamber temperature control was also experimentally demonstrated.

Nagano, Hosei; Nagai, Hiroki; Fukuyoshi, Fuyuko; Ogawa, Hiroyuki

234

Potential benefits of cool roofs on commercial buildings: conserving energy, saving money, and reducing emission of greenhouse gases and air pollutants  

Microsoft Academic Search

Cool roofs—roofs that stay cool in the sun by minimizing solar absorption and maximizing thermal emission—lessen the flow\\u000a of heat from the roof into the building, reducing the need for space cooling energy in conditioned buildings. Cool roofs may\\u000a also increase the need for heating energy in cold climates. For a commercial building, the decrease in annual cooling load\\u000a is

Ronnen Levinson; Hashem Akbari

2010-01-01

235

Thermal performance of phase change wallboard for residential cooling application  

SciTech Connect

Cooling of residential California buildings contributes significantly to electrical consumption and peak power demand mainly due to very poor load factors in milder climates. Thermal mass can be utilized to reduce the peak-power demand, downsize the cooling systems, and/or switch to low-energy cooling sources. Large thermal storage devices have been used in the past to overcome the shortcomings of alternative cooling sources, or to avoid high demand charges. The manufacturing of phase change material (PCM) implemented in gypsum board, plaster or other wall-covering material, would permit the thermal storage to become part of the building structure. PCMs have two important advantages as storage media: they can offer an order-of-magnitude increase in thermal storage capacity, and their discharge is almost isothermal. This allows the storage of high amounts of energy without significantly changing the temperature of the room envelope. As heat storage takes place inside the building, where the loads occur, rather than externally, additional transport energy is not required. RADCOOL, a thermal building simulation program based on the finite difference approach, was used to numerically evaluate the latent storage performance of treated wallboard. Extended storage capacity obtained by using double PCM-wallboard is able to keep the room temperatures close to the upper comfort limits without using mechanical cooling. Simulation results for a living room with high internal loads and weather data for Sunnyvale, California, show significant reduction of room air temperature when heat can be stored in PCM-treated wallboards.

Feustel, H.E.; Stetiu, C.

1997-04-01

236

Thermal performance of various multilayer insulation systems below 80K  

SciTech Connect

The SSC collider dipole cryostat consists of a vacuum shell operating at room temperature, two thermal shields operating near 80K and 20K respectively, and the superconducting magnet assembly operating near 4K. The cryostat design incorporates multilayer insulation (MLI) blankets to limit radiant heat transfer into the 80K and 20K thermal shields. Also, an MLI blanket is used to impede heat transfer through residual gas conduction into the 4K superconducting magnet assembly. A measurement facility at Fermilab has been used to experimentally optimize the thermal insulation system for the dipole cryostat. Previous thermal measurements have been used to define the 80K MLI system configuration and verify system performance. With the 80K MLI system defined, the current effort has focused on experimentally defining the optimum insulation scheme for the 20K thermal shield. The SSC design specification requires that radiant heat transfer be limited to 0.093 W/m[sup 2] at an insulating vacuum of 10[sup [minus]6]torr.

Boroski, W.N.; Nicol, T.H.; Schoo, C.J.

1992-04-01

237

Thermal performance of various multilayer insulation systems below 80K  

SciTech Connect

The SSC collider dipole cryostat consists of a vacuum shell operating at room temperature, two thermal shields operating near 80K and 20K respectively, and the superconducting magnet assembly operating near 4K. The cryostat design incorporates multilayer insulation (MLI) blankets to limit radiant heat transfer into the 80K and 20K thermal shields. Also, an MLI blanket is used to impede heat transfer through residual gas conduction into the 4K superconducting magnet assembly. A measurement facility at Fermilab has been used to experimentally optimize the thermal insulation system for the dipole cryostat. Previous thermal measurements have been used to define the 80K MLI system configuration and verify system performance. With the 80K MLI system defined, the current effort has focused on experimentally defining the optimum insulation scheme for the 20K thermal shield. The SSC design specification requires that radiant heat transfer be limited to 0.093 W/m{sup 2} at an insulating vacuum of 10{sup {minus}6}torr.

Boroski, W.N.; Nicol, T.H.; Schoo, C.J.

1992-04-01

238

Thermal Performance Testing of Glass Microspheres under Cryogenic Vacuum Conditions  

NASA Astrophysics Data System (ADS)

A key element of space launch vehicles and systems is thermal insulation for cryogenic tanks and piping. Glass microspheres, or glass bubbles, represent an alternative insulation material for a number of applications. Composite materials and engineered thermal insulation systems are also being developed based on the use of glass bubbles as the main constituent material. Commonly used materials, such as spray-on foam insulation, or SOFI, for vehicle tanks and perlite powder for ground storage tanks, are targeted for replacement with the new-technology systems that use glass bubbles. Complete thermal characterization of the glass bubbles is the first step toward producing the engineering solutions required for the energy-efficient, low-maintenance cryogenic systems of the future. Thermal performance testing of the glass microsphere material was successfully completed at the Cryogenics Test Laboratory of NASA Kennedy Space Center. The test measurements were made at the full temperature difference (typical boundary temperatures of 78 kelvin [K] and 293 K) and included the full cold-vacuum pressure range. The results are reported in apparent thermal conductivity (k-value) and mean heat flux.

Fesmire, J. E.; Augustynowicz, S. D.

2004-06-01

239

Hydraulic roof-support frame  

Microsoft Academic Search

The roof-engaging assembly of a support frame for a mine roof comprises a main beam having a cantilever extension pivoted to the main beam by pins. In order to pivot the cantilever extension through an angle of about 180-200° between a stowed position and an operative position, a link is pivoted at one point to the main beam and is

Maykemper

1981-01-01

240

The performance check between whole building thermal performance criteria and exterior wall measured clear wall R-value, thermal bridging, thermal mass, and airtightness  

SciTech Connect

At the last IEA Annex 32 meeting it was proposed that the annex develop the links between level 1 (the whole building performance) and level 2 (the envelope system). This paper provides a case study of just that type of connection. An exterior wall mockup is hot box tested and modeled in the laboratory. Measurements of the steady state and dynamic behavior of this mockup are used as the basis to define the thermal bridging, thermal mass benefit and air tightness of the whole wall system. These level two performance characteristics are related to the whole building performance. They can be analyzed by a finite difference modeling of the wall assembly. An equivalent wall theory is used to convert three dimensional heat flow to one dimensional terms that capture thermal mass effects, which in turn are used in a common whole building simulation model. This paper illustrates a performance check between the thermal performance of a Massive ICF (Insulating Concrete Form) wall system mocked up (level 2) and Whole Building Performance criteria (level 1) such as total space heating and cooling loads (thermal comfort).

Kosny, J.; Christian, J.E.; Desjarlais, A.O. [Oak Ridge National Lab., TN (United States). Buildings Technology Center; Kossecka, E. [Polish Academy of Sciences (Poland); Berrenberg, L. [American Polysteel Forms (United States)

1998-06-01

241

Characterization of Inlet Diffuser Performance for Stratified Thermal Storage  

NASA Astrophysics Data System (ADS)

Storage of sensible heating or cooling capacity in stratified vessels has important applications in central heating and cooling plants, power production, and solar energy utilization, among others. In stratified thermal storage systems, diffusers at the top and bottom of a stratified tank introduce and withdraw fluid while maintaining a stable density gradient and causing as little mixing as possible. In chilled water storage applications, mixing during the formation of the thermocline near an inlet diffuser is the single greatest source of thermal losses. Most stratified chilled water storage tanks are cylindrical vessels with diffusers that are either circular disks that distribute flow radially outward or octagonal rings of perforated pipe that distribute flow both inward and outward radially. Both types produce gravity currents that are strongly influenced by the inlet Richardson number, but the significance of other parameters is not clear. The present investigation considers the dependence of the thermal performance of a perforated pipe diffuser on design parameters including inlet velocity, ambient and inlet fluid temperatures, and tank dimensions for a range of conditions representative of typical chilled water applications. Dimensional analysis is combined with a parametric study using results from computational fluid dynamics to obtain quantitative relationships between design parameters and expected thermal performance.

Cimbala, John M.; Bahnfleth, William; Song, Jing

1999-11-01

242

Development of a major center for roof research in the United States  

SciTech Connect

The United States Department of Energy (USDOE) is building a major roof research facility at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, USA. The purpose of the facility will be to carry out research to enhance the thermal performance and durability of low-slope roof systems. The centerpiece of the facility will be an environmental chamber capable of testing up to 3.8 m square roof sections under conditions of temperature, humidity, rain, and uplift air pressures encountered throughout the United States. Other features of this facility will be apparatus for thermophysical and chemical bench testing and a strong mathematical modeling capability. The facility will be designated as a National Users Facility, that is, it will be available to researchers from industry, academia, and other government agencies on a priority basis. USDOE and ORNL will be assisted by an Industrial Review Panel in setting research priorities and arranging schedules. The Facility will be ready for use early in 1988. Facility design features and a preliminary schedule of experiments will be described in this paper.

Courville, G.E.; Huntley, W.R.

1986-01-01

243

Single Port Electro-Thermal Propulsion-Performance Factors  

NASA Astrophysics Data System (ADS)

Performance models for single port ETP (Electro-Thermal Propulsion) devices are presented considering all significant efficiency factors. Single-port ETP devices, which use the nozzle exit as entrance port for beamed power, are capable of high efficiency and high thrust with low mass penalty for both propellant and structure. Previously considered parabolic nozzle shapes have operated in pulse mode to exchange energy at a concentrated focal region, resulting in low efficiency. The proposed cone/bell shape diffuses the focal region prior to chamber entry to allow continuous combustion inside the chamber with high efficiency. Mechanical and thermal limits are evaluated. For vacuum operation, low chamber pressure operation is possible. Thin wall thruster construction results in low chamber and nozzle mass. Further, at low pressure, regenerative cooling is needed only for the chamber and throat region with radiation cooling for the nozzle exit region. These factors permit high expansion ratio and thrust-to-weight ratio needed for performance.

Johansen, Donald G.

2008-04-01

244

40 CFR 65.43 - Fixed roof with an internal floating roof (IFR).  

Code of Federal Regulations, 2013 CFR

...cover or gasketed lid. (iii) Each penetration of the internal floating roof shall...vent shall be gasketed. (v) Each penetration of the internal floating roof that allows...gasketed sliding cover. (vi) Each penetration of the internal floating roof...

2013-07-01

245

Radiative cooling and solar heating potential by using various roofing materials  

SciTech Connect

The results of testing over twenty typical and potential roofing materials such as: corrugated galvanized steel, corrugated clear fiberglass, 90number black roll roofing, 90number green roll roofing, 90number red roll roofing, 90number brown roll roofing, 90number white roll roofing, 240number brown asphalt shingles, anodized aluminum, etc. under exposure to solar and nocturnal sky radiation are presented. Some cadmium sulfite solar cells and silicon solar cells are being tested as potential future roofing panels. Graphs showing the temperature variation of each material versus testing time are given for a heating and a cooling cycle. The environmental conditions of testing such as: solar insolation, apparent sky temperature, ambient air temperature, relative humidity and wind speed are also given. On the basis of preliminary results obtained during the testing of roofing materials, several mini-modules of an integrated collector/radiator/ roof element with the dimensions 0.6 m x 0.6 m (2 ft x 2 ft) were constructed and tested. The thermal response of the mini-modules under solar and nocturnal sky radiation is shown and the testing results are discussed. The spectral transmittance curves for nine transparent cover materials are also presented. The preliminary results indicate that solar radiation and nocturnal sky radiation could be used effectively by employing an integrated collector/radiator structure.

Pytlinski, J.T.; Connell, H.L.; Conrad, G.R.

1980-12-01

246

Heat exchanger thermal performance for two nonazeotropic refrigerant mixtures  

Microsoft Academic Search

Two nonazeotropic refrigerant mixtures (NARMs), the first consisting of 71 percent R22 and 29 percent R114 and the second consisting of 75 percent R143a and 25 percent R124 (approximate percentages by mass), were studied at various mass flow rates and heat loads in an experimental apparatus at Oak Ridge National Laboratory. The measured thermal performance of the evaporator and the

J. C. Conklin; E. A. Vineyard

1991-01-01

247

Thermal performances of different types of underground heat exchangers  

Microsoft Academic Search

An experiment system with different types of U-vertical ground coupled heat exchanger (UGCHE) in situ was set up, for example, single or double U-pipes with sandstone backfills, and single U-pipe with cement backfills. Experiments on the thermal performance of UGCHE were carried out in different conditions, such as different inlet temperature, flow rate, soil types, backfill materials, number of U-pipes

Xinguo Li; Yan Chen; Zhihao Chen; Jun Zhao

2006-01-01

248

Effect of Nanofluid on Flat Heat Pipe Thermal Performance  

Microsoft Academic Search

This study utilizes a silver nano-fluid on a flat heat pipe. It studies the effect of various concentrations on flat heat pipe thermal performance by air-cooling testing equipment. The particles used in these experiments were silver particles 35 nm in size. The base working fluid was pure-water. Nano- fluids were prepared using a two-step method. In the experiment, the thickness

Yu-Tang Chen; Wei-Chiang Wei; Shung-Wen Kang; Chun Sheng

2008-01-01

249

Some aspects of the thermal performance of indigenous powder insulators  

NASA Astrophysics Data System (ADS)

The thermal performances of indigenously available powder materials such as, exfoliated vermiculite, opaque and non-opaque precipitated silica have been studied under various conditions: ie mesh size, packing density, interstitial gas pressure etc., and compared with that of expanded perlite. In this connection scanning electron microscope photographs of these samples have also been taken to have a preliminary information regarding the structure of the materials.

Maiti, C. R.

250

Heat exchanger thermal performance for two nonazeotropic refrigerant mixtures  

NASA Astrophysics Data System (ADS)

Two nonazeotropic refrigerant mixtures (NARMs), the first consisting of 71 percent R22 and 29 percent R114 and the second consisting of 75 percent R143a and 25 percent R124 (approximate percentages by mass), were studied at various mass flow rates and heat loads in an experimental apparatus at Oak Ridge National Laboratory. The measured thermal performance of the evaporator and the condenser are presented in terms of the number of transfer units (NTU) and effectiveness epsilon. Because the phase-change process of the NARMs is nonisothermal, a specific heat for the two-phase region can be defined. This two-phase specific heat for the NARMs varies with respect to enthalpy. Because the standard NTU-(epsilon) analysis is valid only for constant specific heat fluids, an analysis that considers variable specific heat fluids is used to compare analytical predictions of the thermal performance with the observed thermal performance. The predicted and measured results show very good agreement when the pressure drop is low.

Conklin, J. C.; Vineyard, E. A.

1991-08-01

251

Materials performance in prototype Thermal Cycling Absorption Process (TCAP) columns  

SciTech Connect

Two prototype Thermal Cycling Absorption Process (TCAP) columns have been metallurgically examined after retirement, to determine the causes of failure and to evaluate the performance of the column container materials in this application. Leaking of the fluid heating and cooling subsystems caused retirement of both TCAP columns, not leaking of the main hydrogen-containing column. The aluminum block design TCAP column (ABL block TCAP) used in the Advanced Hydride Laboratory, Building 773-A, failed in one nitrogen inlet tube that was crimped during fabrication, which lead to fatigue crack growth in the tube and subsequent leaking of nitrogen from this tube. The Third Generation stainless steel design TCAP column (Third generation TCAP), operated in 773-A room C-061, failed in a braze joint between the freon heating and cooling tubes (made of copper) and the main stainless steel column. In both cases, stresses from thermal cycling and local constraint likely caused the nucleation and growth of fatigue cracks. No materials compatibility problems between palladium coated kieselguhr (the material contained in the TCAP column) and either aluminum or stainless steel column materials were observed. The aluminum-stainless steel transition junction appeared to be unaffected by service in the AHL block TCAP. Also, no evidence of cracking was observed in the AHL block TCAP in a location expected to experience the highest thermal shock fatigue in this design. It is important to limit thermal stresses caused by constraint in hydride systems designed to work by temperature variation, such as hydride storage beds and TCAP columns.

Clark, E.A.

1992-11-21

252

HYDROLOGIC AND WATER QUALITY PERFORMANCE FROM GREENROOFS IN GOLDSBORO AND RALEIGH, NORTH CAROLINA  

Microsoft Academic Search

Two green roofs were constructed and monitored in North Carolina's Neuse River Basin. The hydrologic and water quality performance of each green roof were investigated. Each green roof retained a significant proportion of the rainfall, peak outflows were significantly reduced from the green roofs, and each green roof had substantial delays in runoff. Runoff coefficients from the WCC green roof

Amy Moran; Bill Hunt; Jonathan Smith

253

Analytical and experimental investigations into the performance of a double-pass photovoltaic thermal solar collector  

Microsoft Academic Search

This study presents analytical and experimental investigations of a double-pass photovoltaic thermal solar air collector. Photovoltaic thermal collector is a combination of thermal and photovoltaic systems. It generates both thermal and electrical energies simultaneously. An experimental setup of a double-pass photovoltaic thermal solar air collector was designed and fabricated to study the performance over a range of design and operating

Kamaruzzaman Bin Sopian

1997-01-01

254

The Development of Composites with Negative Thermal Expansion Properties Using High Performance Fibers  

Microsoft Academic Search

Almost all solid materials exhibit positive thermal expansivity. However, in many engineering designs, materials with negative thermal expansivity are desirable. The characteristics of high performance fibers, such as high strength, exceptional thermal conductivity and electrical insulation may also include negative thermal expansivity. Therefore, it should be possible to develop fiber reinforced composites with negative thermal expansivity by using an optimum

Yang Hua; Qing-Qing Ni; Atsuhiko Yamanaka; Yoshihiko Teramoto; Toshiaki Natsuki

2011-01-01

255

Thermal performance of the exterior envelopes of buildings III: Proceedings  

SciTech Connect

This report is a collection of the proceedings of the ASHRAE/DOE/BTECC conference of December 2-5, 1985. The following general topics are covered: In-Situ Measurement of Energy Use; Microclimate and Design Weather Data; Air Infiltration; Thermal Analysis of the Building Envelope; Retrofitting Techniques and Performance; Design of Buildings in Extreme Hot and Cold Climates; Impacts of Moisture; Test Procedure Development and Building Diagnostics; Fenestration and Daylighting; Innovative Construction Practices; Design of Energy-Efficient Envelopes; Guidelines, Standards, and Codes; Thermal Mass and Transient Effects in Buildings and Building Envelopes; Integration of Architecture and Engineering in Energy Conservation Including Economic Optimization. Separate abstracts have been prepared for the individual papers in this proceeding. (JF)

Not Available

1986-01-01

256

The behaviour of roof gable walls under the effect of earthquake load  

NASA Astrophysics Data System (ADS)

In this study, the effect of earthquake loads on roof gable walls and the behaviours of these roof gable walls are investigated. In preparation of the study, two experiments on cradle roof system which gets and does not get any loads off the roof members were carried out in all. The experiments were performed on the shaking table in Earthquake Research Department of General Directorate of Disaster Affairs. Through the experiments, some considerable results were obtained on the behaviours of roof gable walls under the effect of horizontal dynamic loads. The results obtained at the end of these examinations are given and discussed. Furthermore, suggestions to make the brick gable walls more reliable against the loads of earthquake are given. When the results of the experiments were generally taken into consideration, it was realized that the gable walls in both roof systems would partly or completely collapse even under the effect of a little horizontal dynamic load.

Kamanli, M.; Balik, F. S.

2010-02-01

257

Statistical modelling of heat transfer for thermal bridges of buildings  

Microsoft Academic Search

In this paper, we develop statistical models of the thermal transmittance of 2D thermal bridges (?). We aim to give building designers plain and practical tools for the evaluation of the most common 2D thermal bridges. Three examples are considered: a slab-on-grade floor–wall junction, a floor–wall junction and a roof–wall junction. For each case, we perform computer simulations of the

A. Ben Larbi

2005-01-01

258

A Study of The Thermal Performance of Cold-formed Thin-walled Perforated Steel Studs (Thermal Studs) in Fire  

Microsoft Academic Search

Perforating thin-walled steel studs in steel framed housing is an effective method of reducing heat loss and improving energy efficiency. Steel studs with perforation for energy efficiency are called thermal studs. This paper presents an experimental and numerical investigation of the thermal performance of lipped thermal studs in fire. Four tests were carried out in the fire-testing laboratory of the

B. Salhab; Yong Wang

2004-01-01

259

Rehab guide: Roofs. Volume 3  

SciTech Connect

Nine volumes will eventually make up The Rehab Guide in its entirety, and they are listed on the back cover of this volume. Each one is devoted to distinct elements of the house, and within each volume is a range of issues that are common to that element of home rehabilitation work. This volume, Roofs, for example, covers the major roofing systems including framing and sheathing; protective strategies such as underlayments and flashing; energy and air infiltration issues; roofing materials; and gutters and down-spouts. Each volume addresses a wide range techniques, materials, and tools, and recommendations based on regional differences around the country. Throughout The Rehab Guide, special attention is given to issues related to energy efficiency, sustainability, and accessibility.

NONE

1999-03-01

260

Effects of mechanical and thermal fatigue on dental drill performance.  

PubMed

Osseous integration of dental implants depends on the use of proper surgical technique during site preparation, including the prevention of thermal injury to the surrounding bone. Heat generation during drilling has been reported to positively correlate with the production of forces at the surgical site. In this study, peak torque and axial load levels were measured during a drilling procedure into a polymeric material simulating the human mandible. Axial rotary milling was performed using 5 different twist drill designs (3i Irrigated Tri-Spade, 3i Disposable, Nobel-Biocare, Straumann, and Lifecore) of 15 to 20 mm in length and 2 to 2.3 mm in diameter, at a free-running rotational speed of 1,500 rpm and continuous feed rate of 3.5 mm/second, to a total depth of 10.5 mm. Ten drills representing each of the 5 types (n = 50) were subjected to 30 individual drill "pecks" and heat-sterilized every 3 "pecks" to determine the effects of cyclic mechanical and thermal loading on drill performance. Normal stress (sigma) and shear stress (tau) were calculated from the kinetic data and drill geometries. A drill efficiency coefficient (mu) was also calculated as the ratio of torsional resistance to translational resistance. Overall, the hypotheses of drill performance dependency on drill type as well as mechanical and thermal accumulated loading were tested and confirmed (P < .05). The 5 drill types produced a range of normal stresses (2.54 to 5.00 MPa), shear stresses (9.69 to 29.71 MPa), and efficiency (1.16 to 3.16) during repeated testing. Scanning electron microscopic images revealed minor deformations in the cutting edges of the tri-spade drills following testing. PMID:11769832

Harris, B H; Kohles, S S

261

Thermal Performance of Wind Turbine Power System's Engine Room  

NASA Astrophysics Data System (ADS)

Greatly expanded use of wind energy has been proposed to reduce dependence on fossil and nuclear fuels for electricity generation. For wind turbine power generation, as a mature technology in the field of wind power utilization, its large-scale deployment is limited by the cooling technology. Therefore, the temperature distribution of the wind turbine power generation is a key issue for the design of the cooling system. It is because the characteristics of cooling system have a great effect on the performance of the wind turbine power generation. Based on some assumptions and simplifications, a thermal model is developed to describe the heat transfer behavior of wind turbine power system. The numerical calculation method is adopted to solve the governing equation. The heat generation and heat flux are investigated with a given operating boundary. The achieved results can be used to verify whether the cooling system meets the design requirements. Meanwhile, they also can reveal that among the influencing factors, the meteorological conditions, generated output and operation state as well seriously influence its thermal performance. Numerical calculation of the cooling system enables better understanding and results in performance improvement of the system.

Liu, Zhili; Jiang, Yanlong; Zhou, Nianyong; Shi, Hong; Kang, Na; Wang, Yu

262

Parametric thermal analysis of the performance of a thermoelectric generator  

NASA Astrophysics Data System (ADS)

A parametric analysis is presented for the performance of a thermoelectric generator based on its operating conditions. The mathematical model, consisting of non linear equations, is made dimensionless to allow the characteristic parameters to be evidenced. The proposed parameterization lends generality to the results obtained. In particular the relationships have been investigated between the temperature difference inside the thermoelectric cell and that on the outside of the generator, and the effect of the outer thermal resistances of the generator on the working conditions. These parameters have a significant effect on the efficiency and therefore on the optimization of the operating conditions of the thermoelectric generator.

Casano, G.; Piva, S.

2012-11-01

263

Graphite first wall thermal performance in ICF reactor  

NASA Astrophysics Data System (ADS)

Graphite has been considered as a candidate material for the first wall in ICF reactors. This paper shows the thermal performance of the graphite first wall (GFW) in the 0.25 ?m laser driven materials test reactor SIRIUS-M. The first wall temperature response due to the X-rays, reflected laser light, and ions that emanate from the 13.4 MJ yield target was calculated for dry GFWs which were either unprotected or gas protected. Evaporation rates and thermal stresses were calculated and minimum radii were chosen for both cases. It was found that the reflected laser light from the target produces the highest temperature rise in the gas protected GFW. If 10% of the laser light is reflected from the target and the reflectivity of graphite is 50%, the maximum thermal stress in the GFW is about 90% of the compressive strength for a 2 m radius cavity. Therefore, the viability of the first wall design depends critically on the laser light reflected from the target. the graphite reflectivity and the strength of the graphite.

Attaya, H.; Lovell, E.; Engelstad, R.; Peterson, R.; Liang, J.; Abdel-Khalik, S.; Moses, G.; Kulcinski, G.

1986-11-01

264

Roofing Workbook and Tests: Entering the Roofing and Waterproofing Industry.  

ERIC Educational Resources Information Center

This document is one of a series of nine individual units of instruction for use in roofing apprenticeship classes in California. The unit consists of a workbook and test, perforated for student use. Fourteen topics are covered in the workbook and corresponding multiple-choice tests. For each topic, objectives, information sheets, and study…

California State Dept. of Education, Sacramento. Vocational Education Services.

265

Roofing Workbook and Tests: Entering the Roofing and Waterproofing Industry.  

ERIC Educational Resources Information Center

|This document is one of a series of nine individual units of instruction for use in roofing apprenticeship classes in California. The unit consists of a workbook and test, perforated for student use. Fourteen topics are covered in the workbook and corresponding multiple-choice tests. For each topic, objectives, information sheets, and study…

California State Dept. of Education, Sacramento. Vocational Education Services.

266

Development of a Roof Savings Calculator.  

National Technical Information Service (NTIS)

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 to...

A. Desjarlais E. Erdem J. New W. Miller Y. J. Huang

2013-01-01

267

Identifying Roof Fall Predictors Using Fuzzy Classification  

NASA Astrophysics Data System (ADS)

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

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

2010-02-01

268

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

Microsoft Academic Search

Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal, potash, salt etc. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of

Syd S. Peng

2003-01-01

269

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

Microsoft Academic Search

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

Syd S. Peng

2005-01-01

270

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

Microsoft Academic Search

Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal, potash, salt etc. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of

Syd S. Peng

2002-01-01

271

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

Microsoft Academic Search

Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal, potash, salt etc. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of

Syd S. Peng

2001-01-01

272

Cold-Applied Roofing Systems and Waterproofing and Dampproofing. Roofing Workbook and Tests.  

ERIC Educational Resources Information Center

This workbook for students in California roofing apprenticeship programs provides information for classroom work in the area of cold-applied roofing systems and waterproofing and dampproofing. Eight topics are covered: introduction to cold-applied roofing systems and waterproofing and dampproofing, tools and equipment used in cold-applied roofing,…

Brown, Arthur

273

Media depth influences Sedum green roof establishment  

Microsoft Academic Search

Species selection and initial establishment of plants is critical for long term survival and health of green roofs. Plants\\u000a that can withstand harsh environmental conditions and provide rapid coverage on extensive green roofs can reduce erosion,\\u000a limit weed invasion, and provide a more aesthetically pleasing roof to satisfy customers. This study evaluated the effect\\u000a of green roof substrate depth on

Kristin L. Getter; D. Bradley Rowe

2008-01-01

274

Recovery and reuse of asphalt roofing waste: recycling roofing waste to new roofing  

SciTech Connect

A prior DOE study on ten candidate methods for recovering the energy resource represented in asphalt roofing waste showed that incorporating fresh factory waste in new roofing was a potentially viable means for recovering some of the annual 7 x 10/sup 13/ Btu in this waste resource. The project reported here involved measuring the effect of adding factory waste to the asphalt coating compound (called filled coating asphalt). The influence of waste type, size, and quantity on coating asphalt properties such as viscosity, impact resistance, pliability, and service life was measured. In addition, experiments were made to determine if there was a possibility of using field waste (worn-out asphalt roofing) in a similar manner.

Shepherd, P.B.; Powers, T.J.

1987-07-01

275

Performance contracting for parabolic trough solar thermal systems  

SciTech Connect

Several applications of solar energy have proven viable in the energy marketplace, due to competitive technology and economic performance. One example is the parabolic trough solar collectors, which use focused solar energy to maximize efficiency and reduce material use in construction. Technical improvements are complemented by new business practices to make parabolic trough solar thermal systems technically and economically viable in an ever widening range of applications. Technical developments in materials and fabrication techniques reduce production cost and expand applications from swimming pool heating and service hot water, to higher-temperature applications such as absorption cooling and process steam. Simultaneously, new financing mechanisms such as a recently awarded US Department of Energy (DOE) Federal Energy Management Program (FEMP) indefinite quantity Energy Savings Performance Contract (Super ESPC) facilitate and streamline implementation of the technology in federal facilities such as prisons and military bases.

Brown, H.; Hewett, R.; Walker, A. [National Renewable Energy Lab., Golden, CO (United States); Gee, R.; May, K. [Industrial Solar Technology, Golden, CO (United States)

1997-12-31

276

Monitoring the Energy-Use Effects of Cool Roofs on California Commercial Buildings  

SciTech Connect

Solar-reflective roofs stay cooler in the sun than solar-absorptive roofs. Such ''cool'' roofs achieve lower surface temperatures that reduce heat conduction into the building and the building's cooling load. The California Energy Commission has funded research in which Lawrence Berkeley National Laboratory (LBNL) has measured the electricity use and peak demand in commercial buildings to document savings from implementing the Commission's Cool Roofs program. The study seeks to determine the savings achieved by cool roofs by monitoring the energy use of a carefully selected assortment of buildings participating in the Cool Roofs program. Measurements were needed because the peak savings resulting from the application of cool roofs on different types of buildings in the diverse California climate zones have not been well characterized to date. Only a few occupancy categories (e.g., office and retail buildings) have been monitored before this, and those were done under a limited number of climatic conditions. To help rectify this situation, LBNL was tasked to select the buildings to be monitored, measure roof performance before and after replacing a hot roof by a cool roof, and document both energy and peak demand savings resulting from installation of cool roofs. We monitored the effects of cool roofs on energy use and environmental parameters in six California buildings at three different sites: a retail store in Sacramento; an elementary school in San Marcos (near San Diego); and a 4-building cold storage facility in Reedley (near Fresno). The latter included a cold storage building, a conditioning and fruit-palletizing area, a conditioned packing area, and two unconditioned packing areas (counted as one building).

Akbari, Hashem; Levinson, Ronnen; Konopaki, Steve; Rainer, Leo

2004-07-01

277

Handbook for Repairing Nonconventional Roofing Systems.  

National Technical Information Service (NTIS)

As built-up roofs (BURs) on Army facilities wear out, many are being replaced with nonconventional roofing systems. Problems can arise when a roof mechanic uses a repair procedure appropriate for a BUR to repair a defect in one of the newer nonconventiona...

C. Doyle W. Dillner M. J. Rosenfield

1988-01-01

278

30 CFR 75.204 - Roof bolting.  

Code of Federal Regulations, 2013 CFR

...taken. (3) The installed torque or tension ranges for roof bolts as specified in...roof bolting cycle, the actual torque or tension of the first tensioned roof bolt installed...shall be measured for actual torque or tension. If the torque or tension of any...

2013-07-01

279

Seismic qualification of building roof structure  

Microsoft Academic Search

This paper presents a method for qualifying the existing roof structure of the Fuels and Materials Examination Facility (FMEF) at the US Department of Energy's Hanford Site in Richland, Washington. The roof is a safety class 1 structure and subject to the design-basis earthquake (DBE). The roof consists of 26 prestressed concrete T-beams 82 feet long spaced 6 feet on

M. A. Islam; R. B. Pan

1991-01-01

280

Roofing shingle assembly having solar capabilities  

SciTech Connect

A roofing shingle assembly having solar capabilities comprising a flat main portion having upper and lower surfaces, and curved segments integral with the upper and lower edges of said shingle. The roofing shingles are mounted in overlapping parallel array with the curved segments interconnected to define a fluid conduit enclosure. Mounting brackets for the shingles are secured on the roof rafters.

Murphy, J.A.

1982-03-16

281

Mine roof geology information system  

Microsoft Academic Search

A project sponsored by the US Department of Energy under the Industry of Future (Mining) program was initiated five years ago. In this project a patented drill control unit (DCU) installed DIN. the J.H. Flecher & Co.'s roof bolter was used to record the drilling parameter for experiments conducted in the mines and laboratory. Today, the drilling parameters have been

S. S. Peng; T. Sasaoka; D. X. Tang; Y. Wilson; G. Wilson

2005-01-01

282

Passive solar roof ice melter  

SciTech Connect

An elongated passive solar roof ice melter is placed on top of accumulated ice and snow including an ice dam along the lower edge of a roof of a heated building and is held against longitudinal movement with respect to itself. The melter includes a bottom wall having an upper surface highly absorbent to radiant solar energy; a first window situated at right angles with respect to the bottom wall, and a reflecting wall connecting the opposite side edges of the bottom wall and the first window. The reflecting wall has a surface facing the bottom wall and the window which is highly reflective to radiant solar energy. Radiant solar energy passes through the first window and either strikes the highly absorbent upper surface of the bottom wall or first strikes the reflecting wall to be reflected down to the upper surface of the bottom wall. The heat generated thereby melts through the ice below the bottom wall causing the ice dam to be removed between the bottom wall and the top of the roof and immediately adjacent to the ice melter along the roof. Water dammed up by the ice dam can then flow down through this break in the dam and drain out harmlessly onto the ground. This prevents dammed water from seeping back under the shingles and into the house to damage the interior of the house.

Deutz, R.T.

1981-09-29

283

Roof for the Lions' House.  

National Technical Information Service (NTIS)

Fans of the National Football League s Detroit Lions don't worry about game day weather. Their magnificent new Pontiac Stadium has a domed, air-supported, fabric roof that admits light but protects the playing field and patrons from the elements. The 80,0...

1978-01-01

284

A Roof for ALMA  

NASA Astrophysics Data System (ADS)

On 10 March, an official ceremony took place on the 2,900m high site of the Atacama Large Millimeter/submillimeter Array (ALMA) Operations Support Facility, from where the ALMA antennas will be remotely controlled. The ceremony marked the completion of the structural works, while the building itself will be finished by the end of the year. This will become the operational centre of one of the most important ground-based astronomical facilities on Earth. ESO PR Photo 13a/07 ESO PR Photo 13a/07 Cutting the Red Ribbon The ceremony, known as 'Tijerales' in Chile, is the equivalent to the 'roof-topping ceremony' that takes place worldwide, in one form or another, to celebrate reaching the highest level of a construction. It this case, the construction is the unique ALMA Operations Support Facility (OSF), located near the town of San Pedro de Atacama. "The end of this first stage represents an historic moment for ALMA," said Hans Rykaczewski, the European ALMA Project Manager. "Once completed in December 2007, this monumental building of 7,000 square metres will be one of the largest and most important astronomical operation centres in the world." ALMA, located at an elevation of 5,000m in the Atacama Desert of northern Chile, will provide astronomers with the world's most advanced tool for exploring the Universe at millimetre and submillimetre wavelengths. ALMA will detect fainter objects and be able to produce much higher-quality images at these wavelengths than any previous telescope system. The OSF buildings are designed to suit the requirements of this exceptional observatory in a remote, desert location. The facility, which will host about 100 people during operations, consists of three main buildings: the technical building, hosting the control centre of the observatory, the antenna assembly building, including four antenna foundations for testing and maintenance purposes, and the warehouse building, including mechanical workshops. Further secondary buildings are the transporter shelters and the vehicle maintenance facilities as well as the ALMA gate house. The construction started in August 2006 and will be completed in December 2007. ESO PR Photo 13b/07 ESO PR Photo 13b/07 The Ceremony The ceremony took place in the presence of representatives of the regional authorities, members of the Chilean Parliament, and representatives of the local community, including the mayor of San Pedro, Ms. Sandra Berna, who joined more than 40 representatives of ESO, NRAO and NAOJ - the organisations that are, together, building ALMA. "This is certainly a big step in the realisation of the ALMA Project. The completion of this facility will be essential for assembly, testing and adjustment as well as operation and maintenance of all ALMA antennas from Europe, North America and from Japan," said Ryusuke Ogasawara, the representative of NAOJ in Chile. "This is a tremendous achievement and represents a major milestone for the ALMA project," said Adrian Russell, North American Project Manager for ALMA. ESO PR Photo 13c/07 ESO PR Photo 13c/07 The OSF (Artist's View) The first ALMA antennas, the prototypes of which successfully achieved their first combined astronomical observation last week, are expected to arrive at the ALMA site in a few months. These huge antennas will travel in pieces from Europe, USA and Japan and will be assembled next to the OSF building. The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership among Europe, Japan and North America, in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organisation for Astronomical Research in the Southern Hemisphere, in Japan by the National Institutes of Natural Sciences (NINS) in cooperation with the Academia Sinica in Taiwan and in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC). ALMA construction and operations are led on behalf of Europe by ESO, on behalf of Japan by the National As

2007-03-01

285

Investigating the impact of thermal mass on building performance using computational simulation  

Microsoft Academic Search

Many building designers believe that thermal mass can significantly enhance the thermal performance of buildings in cold climate. This paper presents the technical details of a computational simulation study, showing that thermal mass distribution do not generate significant energy saving for a high-rise apartment buildings in cold climate. Six configurations, each with different level of thermal mass and distribution schemes,

E. S. W. Wong; Zaiyi Liao

2010-01-01

286

Integrated analysis of nuclear thermal rocket system performance  

SciTech Connect

As part of the Space Exploration Initiative (SEI), nuclear thermal rocket (NTR) engines will play a key transportation role. Although a number of tests of prismatic, solid-core nuclear engines were completed during the ROVER/NERVA program, the estimated cost of completing full-engine tests will severely limit the scope, duration, and number of any such tests in the future. Design optimization by test iteration is unlikely, and an emphasis on computational modeling is a cost-effective alternative. As a consequence of our responsibilities within the US Dept. of Energy's SEI efforts to develop key NTR technologies, Los Alamos National Laboratory (LANL) is developing the capability to design and verify the safety and performance of NTR systems. Because of the important role that computational modeling will play in the faster, better, and cheaper development of an NTR system, we are pursuing two paths of analysis. The first undertaking is the development of accurate separate-effects codes for design and analysis. Included in this category are thermal-hydraulic and radiation-transport codes. Our other endeavor, which is the focus of this paper, is to develop an advanced computational architecture that can be used to model the entire NTR system.

Buksa, J.J.; Rider, W.J.; Hall, M.; Perry, R.T.; Houts, M. (Los Alamos National Lab., NM (United States))

1992-01-01

287

Thermal performance of fiberglass and cellulose attic insulations  

SciTech Connect

A series of experiments has been completed on the thermal performance of fiberglass and cellulose attic insulations under winter conditions using an attic test module in a guarded hot box facility. Experiments with one type of loose-fill fiberglass insulation showed that the thermal resistance at large temperature differences (70 to 76{degrees}F) was about 35 to 50% less than at small temperature differences. The additional heat flow, attributed to natural convection, was effectively eliminated by applying a covering of fiberglass batts or a combination of a polyethylene film and fiberglass blankets. No significant convection was found either with fiberglass batts or with one type of loose-fill cellulose. Using the experimental data along with an attic model, the additional energy costs due to convection in the coldest climate investigated were estimated to be $0.025/ft{sup 2}yr to $0.028/ft{sup 2}yr at the R-19 level and $0.014/ft{sup 2}yr at the R-38 level. For the same conditions, annual energy savings due to upgrading insulation from the R-19 to the R-38 level were estimated to be $0.046/ft{sup 2}yr to $0.070/ft{sup 2}yr.

Wilkes, K.E.; Childs, P.W.

1992-10-01

288

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

PubMed

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. PMID:17368704

Carter, Timothy; Keeler, Andrew

2007-03-21

289

THERMAL PERFORMANCE OF RADIOACTIVE MATERIAL PACKAGES IN TRANSPORT CONFIGURATION  

SciTech Connect

Drum type packages are routinely used to transport radioactive material (RAM) in the U.S. Department of Energy (DOE) complex. These packages are designed to meet the federal regulations described in 10 CFR Part 71. The packages are transported in specially designed vehicles like Safe Secure Transport (SST) for safety and security. In the transport vehicles, the packages are placed close to each other to maximize the number of units in the vehicle. Since the RAM contents in the packagings produce decay heat, it is important that they are spaced sufficiently apart to prevent overheating of the containment vessel (CV) seals and the impact limiter to ensure the structural integrity of the package. This paper presents a simple methodology to assess thermal performance of a typical 9975 packaging in a transport configuration.

Gupta, N.

2010-03-04

290

Performance study of a thermal-envelope house: Phase II. Cooling performance. Final report  

Microsoft Academic Search

The thermal envelope house is shown to perform much better than conventional houses without mechanical refrigeration and better than one would expect from most passively cooled houses in the hot-humid climate of Georgia. Peak temperatures inside the house were 8 to 15°F below peak ambient temperatures. Peak inside temperature measured during the test period was 80°F with an outside ambient

J. M. Akridge; C. C. Benton

1981-01-01

291

Trussed Rafter Roofs.  

National Technical Information Service (NTIS)

Surveys were carried out in the UK of the manufacture, site use and performance in service of trussed rafters. Assessments were made of the degree of compliance with Code of Practice recommendations covering these aspects.

A. P. Mayo D. F. G. Rodwell J. W. W. Morgan

1983-01-01

292

Building America Best Practices Series, Volume 6: High-Performance Home Technologies: Solar Thermal & Photovoltaic Systems  

SciTech Connect

This guide is was written by PNNL for the US Department of Energy's Building America program to provide information for residential production builders interested in building near zero energy homes. The guide provides indepth descriptions of various roof-top photovoltaic power generating systems for homes. The guide also provides extensive information on various designs of solar thermal water heating systems for homes. The guide also provides construction company owners and managers with an understanding of how solar technologies can be added to their homes in a way that is cost effective, practical, and marketable. Twelve case studies provide examples of production builders across the United States who are building energy-efficient homes with photovoltaic or solar water heating systems.

Baechler, Michael C.; Gilbride, Theresa L.; Ruiz, Kathleen A.; Steward, Heidi E.; Love, Pat M.

2007-06-04

293

HIGH-PERFORMANCE PHASECHANGE THERMAL ENERGY STORAGE USING SPHERICAL CAPSULES  

Microsoft Academic Search

A theoretical and experimental investigation of the transient thermal characteristics of a phase-change thermal energy storage (TES) unit using spherical capsules is presented. A simulation program that considers rigorously transient aspects of both the surrounding heat transfer fluid and the phase change material (PCM) packed inside the spherical capsule is developed. The overall thermal response of this TES unit is

T. SAITOH; K. HIROSE

1986-01-01

294

Comparison of Theory and Experiment for Photovoltaic/Thermal Collector Performance.  

National Technical Information Service (NTIS)

Detailed performance testing of an air and a liquid type combined photovoltaic/thermal (PV/T) collector has been completed with results of accompanying analytical modeling accurately predicting the experimental data. Thermal efficiencies, with concurrent ...

S. D. Hendrie

1980-01-01

295

Thermal radiant exitance model performance: soils and forests  

NASA Astrophysics Data System (ADS)

Models of surface temperatures of two land surface types based on their energy budgets were developed to simulate the effects of environmental factors on thermal radiant exitance. The performance of these models is examined in detail. One model solves the non-linear differential equation for heat diffusion in solids using a set of submodels for surface energy budget components. The model performance is examined under three desert conditions thought to be a strong test of the submodels. The accuracy of the temperature predictions and submodels is described. The accuracy of the model is generally good but some discrepancies between some of the submodels and measurements are noted. The sensitivity of the submodels is examined and is seen to be strongly controlled by interaction and feedback among energy components that are a function of surface temperature. The second model simulates vegetation canopies with detailed effects of surface geometry on radiant transfer in the canopy. Foliage solar absorption coefficients are calculated using a radiosity approach for a three layer canopy and long wave fluxes are modeled using a view factor matrix. Sensible and latent heat transfer through the canopy are also simulated using nearby meteorological data but heat storage in the canopy is not included. Simulations for a coniferous forest canopy are presented and the sensitivity of the model to environmental inputs is discussed.

Balick, Lee K.; Smith, James A.

1995-01-01

296

Low cost photovoltaic roof tile  

Microsoft Academic Search

Static concentrator designs that achieve concentration ratios approaching the theoretical limit have been developed and demonstrated. Concentration ratios in excess of 4:1 have been predicted although this reduces to 3.6:1 for the practical design used for photovoltaic roof tile applications. A new encapsulant based on “solid white oil” has been evaluated for use in the optical cavity, exhibiting excellent optical

S. R. Wenham; S. Bowden; M. Dickinson; R. Largent; N. Shaw; C. B. Honsberg; M. A. Green; P. Smith

1997-01-01

297

Thermal performance of a simple design solar air heater with built-in thermal energy storage system  

Microsoft Academic Search

The thermal performance of a simple design solar air heater is presented. The conventional flat plate absorber is replaced by a set of tubes filled with a thermal energy storage material. The proposed integrated system heat transfer area and heat transfer coefficient are increased, and the heat loss is reduced. Based on a simple transient analysis, explicit expressions for the

Hassan E. S. Fath

1995-01-01

298

Demonstration of energy savings of cool roofs  

SciTech Connect

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.

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

299

Inclusion of cool roofs in nonresidential Title 24 prescriptiverequirements  

SciTech Connect

Roofs that have high solar reflectance (high ability toreflect sunlight) and high thermal emittance (high ability to radiateheat) tend to stay cool in the sun. The same is true of low-emittanceroofs with exceptionally high solar reflectance. Substituting a cool rooffor a non-cool roof tends to decrease cooling electricity use, coolingpower demand, and cooling-equipment capacity requirements, while slightlyincreasing heating energy consumption. Cool roofs can also lower citywideambient air temperature in summer, slowing ozone formation and increasinghuman comfort.DOE-2.1E building energy simulations indicate that use of acool roofing material on a prototypical California nonresidential (NR)building with a low-sloped roof yields average annual cooling energysavings of approximately 3.2 kW h/m2 (300 kW h/1000 ft2), average annualnatural gas deficits of 5.6 MJ/m2 (4.9 therm/1000 ft2), average annualsource energy savings of 30 MJ/m2 (2.6 MBTU/1000 ft2), and average peakpower demand savings of 2.1 W/m2 (0.19 kW/1000 ft2). The 15-year netpresent value (NPV) of energy savings averages $4.90/m2 ($450/1000 ft2)with time-dependent valuation (TDV), and $4.00/m2 ($370/1000 ft2) withoutTDV. When cost savings from downsizing cooling equipment are included,the average total savings (15-year NPV+equipment savings) rises to$5.90/m2 ($550/1000 ft2) with TDV, and to $5.00/m2 ($470/1000 ft2)without TDV.Total savings range from 1.90 to 8.30 $/m2 (0.18 0.77 $/ft2)with TDV, and from 1.70 to 7.10 $/m2 (0.16 0.66 $/ft2) without TDV,across California's 16 climate zones. The typical cost premium for a coolroof is 0.00 2.20 $/m2 (0.00 0.20 $/ft2). Cool roofs with premiums up to$2.20/m2 ($0.20/ft2) are expected to be cost effective in climate zones 216; those with premiums not exceeding $1.90/m2 ($0.18/ft2) are expectedto be also cost effective in climate zone 1. Hence, this study recommendsthat the year-2005 California building energy efficiency code (Title 24,Part 6 of the California Code of Regulations) for NR buildings withlow-sloped roofs include a cool-roof prescriptive requirement in allCalifornia climate zones. Buildings with roofs that do not meetprescriptive requirements may comply with the code via an"overall-envelope" approach (non-metal roofs only), or via a performanceapproach (all roof types).

Levinson, Ronnen; Akbari, Hashem; Konopacki, Steve; Bretz, Sarah

2003-07-01

300

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

SciTech Connect

Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal, potash, salt etc. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on such information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. In this quarter, retrofitting work to build a dedicated roof bolter for this research has been started. A number of numerical methods have been developed to improve the quality of and to analyze the collected drilling parameters. Finite element modeling of roof bolting mechanism is continuing.

Syd S. Peng

2001-07-15

301

Predicting performance of optical systems undergoing thermal/mechanical loadings using integrated thermal/structural/optical numerical methods  

NASA Astrophysics Data System (ADS)

Prediction of the performance of electro-optical systems operating under thermal/mechanical loadings is achieved by integrating computer-based numerical tools. Thermal, structural, and optical computer programs are interfaced on both CDC 6600 and Honeywell 6080 computers into a Thermal/Structural/Optical (TSO) evaluation process. The TSO process integrates the separate analyses by automatizing data transfers among the individual technology programs to allow rapid evaluation of optical systems undergoing thermal/mechanical loadings. The design/analysis process involves iterations of the following: thermal/mechanical error budgets, TSO evaluations of electro-optical systems, and comparisons of TSO results with error budget line items. The way in which the TSO process has interfaced the individual technology programs is discussed, and examples of TSO applications to electro-optics systems and test data from systems that have been subjected to thermal/mechanical loadings are presented.

Miller, J.; Hatch, M.; Green, K.

1981-04-01

302

Numerical analysis of heat transfer by conduction and natural convection in loose-fill fiberglass insulation--effects of convection on thermal performance  

SciTech Connect

A two-dimensional code for solving equations of convective heat transfer in porous media is used to analyze heat transfer by conduction and convection in the attic insulation configuration. The particular cases treated correspond to loose-fill fiberglass insulation, which is characterized by high porosity and air permeability. The effects of natural convection on the thermal performance of the insulation are analyzed for various densities, permeabilities, and thicknesses of insulation. With convection increasing the total heat transfer through the insulation, the thermal resistance was found to decrease as the temperature difference across the insulating material increases. The predicted results for the thermal resistance are compared with data obtained in the large-scale climate simulator at the Roof Research Center using the attic test module, where the same phenomenon has already been observed. The way the wood joists within the insulation influence the start of convection is studied for differing thermophysical and dynamic properties of the insulating material. The presence of wood joists induces convection at a lower temperature difference.

Delmas, A.A.; Wilkes, K.E.

1992-04-01

303

Comparative thermal performance of direct gain, Trombe, and sunspace walls  

Microsoft Academic Search

The natural thermal storage features of the Brookhaven superinsulated house were analyzed and verified. These include the Trombe and sunspace passive-solar-collection walls and the superinsulated south-facing wall. The thermal contributions of each system were demonstrated. Several thermal characteristic factors, in relation to each design for the hourly and daily period, were assessed. Further, the interior temperature fluctuations and the reductions

H. T. Ghaffari; R. F. Jones

1981-01-01

304

Performance of solar thermal systems with liquid metal MHD conversion  

NASA Astrophysics Data System (ADS)

Liquid metal magnetohydrodynamic conversion (LMMHD) is found to be compatible with concentrating solar receivers employing a liquid metal as a heat transfer medium and offers significant increases in the system thermal efficiency over the 33% considered attainable with conventional turbo-machinery. There are two candidate liquid metals - sodium and lithium. With sodium at a temperature of 1150 F (922 K), the maximum calculated efficiency is 39.5% while with lithium at 1400 F (1033 K) a peak efficiency for 46.5% is predicted. Up to two percentage points may be added by temperature increase and/or parameter limit relaxation in the sodium case. The sodium steam heat exchanger is eliminated in liquid metal systems. Where LMMHD systems employ the same working fluid as the solar receiver, no recirculating pump is required as pumping power is provided directly by the cycle. For sodium, coupling with either a gas turbine or a steam turbine is beneficial and provides similar performance. With lithium, the gas turbine cycle is clearly superior.

Pierson, E. S.; Jackson, W. D.; Berry, G.; Petrick, M.; Dennis, C.

1984-06-01

305

Hydrogen recombination kinetics and nuclear thermal rocket performance prediction  

SciTech Connect

The rate constants for the hydrogen three-body collisional recombination reaction with atomic and molecular hydrogen acting as third bodies have been determined by numerous investigators during the past 30 yr, but these rates exhibit significant scatter. The discrepancies in the rate constants determined by different investigators are as great as two orders of magnitude in the temperature range of interest for nuclear thermal rocket (NTR) operation, namely, 2000-3300 K. The impact of this scatter on our ability to predict the specific impulse (I(sub sp)) delivered by a 30-klbf NTR has been determined for chamber pressures and temperatures from, respectively, 20-1000 psia and 2700-3300 K. The variation in I(sub sp) produced by using the different rate constants is as great as 10%, or 100 s. This variation also obscures the influence of chamber pressure on I(sub sp); using fast kinetics, low pressures yield significantly improved performance, while using slow or nominal kinetics, the pressure dependence of I(sub sp) is negligible. Because the flow composition freezes at very small area ratios, optimization of the nozzle contour in the near-throat region maximizes recombination. Vibrational relaxation is found to produce negligible losses in I(sub sp). 36 refs.

Wetzel, K.K.; Solomon, W.C. [Univ. of Illinois, Urbana-Champaign, Urbana, IL (United States)

1994-07-01

306

Hydrogen recombination kinetics and nuclear thermal rocket performance prediction  

NASA Astrophysics Data System (ADS)

The rate constants for the hydrogen three-body collisional recombination reaction with atomic and molecular hydrogen acting as third bodies have been determined by numerous investigators during the past 30 yr, but these rates exhibit significant scatter. The discrepancies in the rate constants determined by different investigators are as great as two orders of magnitude in the temperature range of interest for nuclear thermal rocket (NTR) operation, namely, 2000-3300 K. The impact of this scatter on our ability to predict the specific impulse (I(sub sp)) delivered by a 30-klbf NTR has been determined for chamber pressures and temperatures from, respectively, 20-1000 psia and 2700-3300 K. The variation in I(sub sp) produced by using the different rate constants is as great as 10%, or 100 s. This variation also obscures the influence of chamber pressure on I(sub sp); using fast kinetics, low pressures yield significantly improved performance, while using slow or nominal kinetics, the pressure dependence of I(sub sp) is negligible. Because the flow composition freezes at very small area ratios, optimization of the nozzle contour in the near-throat region maximizes recombination. Vibrational relaxation is found to produce negligible losses in I(sub sp).

Wetzel, Kyle K.; Solomon, Wayne C.

1994-07-01

307

Performance study of a thermal-envelope house: Phase II. Cooling performance. Final report  

SciTech Connect

The thermal envelope house is shown to perform much better than conventional houses without mechanical refrigeration and better than one would expect from most passively cooled houses in the hot-humid climate of Georgia. Peak temperatures inside the house were 8 to 15/sup 0/F below peak ambient temperatures. Peak inside temperature measured during the test period was 80/sup 0/F with an outside ambient peak of 93/sup 0/F. Air flow rates within the envelope were less than 1 ft/sec even when the attic fan was operating. The earth cooling tubes provided noticeable sensible cooling to the house. Exit temperatures from the cooling tubes were between 72 to 76/sup 0/F, depending upon the air velocity through the tubes. The thermal chimney performed poorly as an air mover, especially when used to induce flow through the earth cooling tubes. The performance of the earth cooling tube could be improved by using the attic fan to increase the air flow through the cooling tubes and to insure it flowed in the cooling tube, through the envelope and out the thermal chimney. Being an exhaust fan, the attic fan created a negative pressure in the house. While this increased air flow through the cooling tubes, it also increased air infiltration through the building shell, thus increasing load. The humidity level within the living space remains relatively high year-round due to low rates of air infiltration and water vapor transmission through the building skin. The problem is aggravated during the summer by the introduction of cool moist air from the cooling tubes to the envelope and frequently to the inner space. While the cooling tubes are able to reduce the sensible load, and they are incapable of significantly reducing humidity or latent loads. This results in relatively comfortable air temperatures but uncomfortable humidities within the living space.

Akridge, J.M.; Benton, C.C.

1981-01-01

308

Roofing and siding rehabs get an energy fix  

SciTech Connect

Replacement of worn siding and roof coverings brings an opportunity to upgrade energy efficiency of both. This article discusses several options for incorporating energy retrofits into roof and wood siding rehabs. Topics include the following: roofing: shallow rafter pitch, cathedral and sloped ceilings, roof venting, white roofs for cool homes; siding: adding rigid foam, added insulation pay off. 3 tabs., 2 figs.

Fisette, P. [Lawrence Berkeley National Lab., CA (United States)

1996-11-01

309

Green roof vegetation for North American ecoregions: A literature review  

Microsoft Academic Search

A green roof is a vegetated roof or deck designed to provide urban greening for buildings, people, or the environment. Made popular across Europe over the past few decades, green roofs are now becoming more familiar to North Americans as some cities have built green roof pilot projects and adopted incentives for using green roofs or even require their use.

Bruce Dvorak; Astrid Volder

2010-01-01

310

Thermal performance study of box type solar cooker from heating characteristic curves  

Microsoft Academic Search

The top heat losses that constitute the major losses from the box type solar cooker have a strong influence on the thermal performance. To predict or evaluate the thermal performance of a cooker, the top heat loss coefficient Utw for a water loaded cooker must be known. In the present study, several indoor and outdoor experiments were performed on a

Subodh Kumar

2004-01-01

311

Performance testing of thermal analysis codes for nuclear fuel casks  

Microsoft Academic Search

In 1982 Sandia National Laboratories held the First Industry\\/Government Joint Thermal and Structural Codes Information Exchange and presented the initial stages of an investigation of thermal analysis computer codes for use in the design of nuclear fuel shipping casks. The objective of the investigation was to (1) document publicly available computer codes, (2) assess code capabilities as determined from their

1987-01-01

312

Thermal performance modeling of NASA’s scientific balloons  

Microsoft Academic Search

Initial studies of the thermal profiles on scientific balloons along with preliminary results are discussed in this paper. This document also emphasizes the impact thermal modeling will have on the design and future development of the scientific balloons. Progress of study and future steps to keep up with the design criteria is also included in this document.

H. Franco; H. M. Cathey

2004-01-01

313

Study on the Relations between Roof Shallow Strata Type and Roof Caving Hidden Danger Level  

Microsoft Academic Search

In order to explore relationship between the different types of shallow roof, different structure combination of roof strata and the level of roof caving hidden danger. Based on roof stability partition method, using RFPA software, respectively on set a model about Soft-toughening type rock, Soft-brittle type rock, Medium-toughening type rock, Medium strength-Medium stiffness type rock, Hard-toughening type rock and Hard-brittle

Liu Hongtao; Tao Han; Chen Tao; Ren Qinhua; Zhu Zhentao

2012-01-01

314

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

SciTech Connect

In this quarter, the field, theoretical and programming works have been performed toward achieving the research goals set in the proposal. The main accomplishments in this quarter included: (1) laboratory tests have been conducted, (2) with the added trendline analysis method, the accuracy of the data interpretation methodology will be improved and the interfaces and voids can be more reliably detected, (3) method to use torque to thrust ratio as indicator of rock relative hardness has also been explored, and (4) about 80% of the development work for the roof geology mapping program, MRGIS, has completed.

Syd S. Peng

2003-01-15

315

EVALUATION OF ROOF BOLTING REQUIREMENTS BASED ON IN MINE ROOF BOLTER DRILLING  

SciTech Connect

In this quarter, the field, theoretical and programming works have been performed toward achieving the research goals set in the proposal. The main accomplishments in this quarter included: (1) laboratory tests have been conducted, (2) with the added trendline analysis method, the accuracy of the data interpretation methodology will be improved, (3) method to use torque to thrust ratio as indicator of rock relative hardness has also been explored, and (3) about one half of the development work for the roof geology mapping program, MRGIS, has completed.

Syd S. Peng

2003-10-15

316

Modeling of target thermal structure effects on the performance of staring IR seekers  

Microsoft Academic Search

The target thermal structure is playing a stronger role in modeling the performance of autonomous IR seekers to acquire and track targets. The impact of the target thermal structure on seeker and sensor acquisition has been previously reported. In this paper, the impact of the target's thermal structure on the acquisition and tracking capability of autonomous imaging IR seekers using

Eric J. Borg

1994-01-01

317

Comparison of the thermal performance of double U-pipe borehole heat exchangers measured in situ  

Microsoft Academic Search

A borehole heat exchanger is a ground heat exchanger devised for the extraction or injection of thermal energy from\\/into the ground. The thermal performance of a borehole heat exchanger can be assessed with a response test. The response test method allows the in situ determination of the thermal conductivity of the ground in the vicinity of a borehole heat exchanger,

D. Pahud; B. Matthey

2001-01-01

318

Experimental investigations of fluid dynamic and thermal performance of nanofluids  

NASA Astrophysics Data System (ADS)

The goal of this research was to investigate the fluid dynamic and thermal performance of various nanofluids. Nanofluids are dispersions of metallic nanometer size particles (<100 nm) into the base fluids. The choice of base fluid is an ethylene or propylene glycol and water mixture in cold regions. Initially the rheological characterization of copper oxide (CuO) nanofluids in water and in propylene glycol was performed. Results revealed that higher concentrations of CuO nanoparticles (5 to 15%) in water exhibited time-independent pseudoplastic and shear-thinning behavior. Lower concentrations (1 to 6%) of CuO nanofluids in propylene glycol revealed that these nanofluids behaved as Newtonian fluids. Both nanofluids showed that viscosity decreased exponentially with increase in temperature. Subsequent correlations for viscosities as a function of volume concentration and temperature were developed. Effects of different thermophysical properties on the Prandtl number of CuO, silicon dioxide (SiO2) and aluminum oxide (A12O 3) nanofluids were investigated. Results showed that the Prandtl number increased with increasing volume concentrations, which in turn increased the heat transfer coefficients of the nanofluids. Various nanofluids were compared for their heat transfer rates based on the Mouromtseff number, which is a Figure of Merit for heat transfer fluids. From this analysis, the optimal concentrations of nanoparticles in base fluids were found for CuO-water nanofluids. Experiments were performed to investigate the convective heat transfer enhancement and pressure loss of CuO, SiO2 and A12O 3 nanofluids in the turbulent regime. The increases in heat transfer coefficient by nanofluids for various volume concentrations compared to the base fluid were determined. Pressure loss was observed to increase with nanoparticle volume concentration. It was observed that an increase in particle diameter increased the heat transfer coefficient. Calculations showed that application of nanofluids in heat exchangers in buildings could result in volumetric flow reduction, reduction in the mass flow rate and size, and pumping power savings. Experiments on a diesel electric generator with nanofluids showed a reduction of cogeneration efficiency due to the decrease in specific heat compared to the base fluids. However, it was found that the efficiency of the waste heat recovery heat exchanger increased for nanofluids.

Kulkarni, Devdatta Prakash

319

The Effects of Roof Membrane Color on Moisture Accumulation in Low-slope Commercial Roof Systems  

SciTech Connect

The use of highly reflective roof membrane systems is being promoted and in some cases required in energy codes and green building codes and standards. Highly reflective membranes, which typically are light in color, have demonstrated reduced overall energy consumption in cooling dominated climate. These membranes also are theorized to reduce the heat island effect. Concern has been expressed about using highly reflective roof membrane systems in cool to cold climate zones because they potentially increase moisture accumulation in roof systems. Roof membranes are vapor retarders. The theory is that highly reflective membranes reflect the heat that could enter the roof assembly, potentially providing a condensing surface on the cold side of the roof assembly during winter months. The other concern is that roof systems using highly reflective membranes will not get hot enough during the summer months to dry out moisture that may have condensed or otherwise entered the roof assembly. This study focuses on mechanically attached, highly reflective, single-ply roof systems installed on low-slope (less than 2:12) structures in cool to cold climate zones. Three sources of data are considered when determining the moisture accumulation potential of these systems. 1.Test roof cuts taken during the winter months 2.Modeling data from a building envelope model specifically designed to evaluate moisture accumulation 3.Data from previous studies to determine the effects of roof membrane color on the drying rate of low-slope roof assemblies

Kehrer, Manfred [ORNL

2011-01-01

320

Part A: Assessing the performance of the COMFA outdoor thermal comfort model on subjects performing physical activity  

Microsoft Academic Search

This study assessed the performance of the COMFA outdoor thermal comfort model on subjects performing moderate to vigorous\\u000a physical activity. Field tests were conducted on 27 subjects performing 30 min of steady-state activity (walking, running,\\u000a and cycling) in an outdoor environment. The predicted COMFA budgets were compared to the actual thermal sensation (ATS) votes\\u000a provided by participants during each 5-min interval.

Natasha A. Kenny; Jon S. Warland; Robert D. Brown; Terry G. Gillespie

2009-01-01

321

70 FR 49223 - Federal Motor Vehicle Safety Standards; Roof Crush Resistance  

Federal Register 2010, 2011, 2012, 2013

...NHTSA, before the Committee on Commerce, Science, and Transportation. U.S. Senate...factor of 2.5. Safety Analysis and Forensic Engineering (SAFE) and Syson-Hille...difficult to discriminate between good and bad performing roof structures,...

2005-08-23

322

Thermal performance of LSCO and LSFO films for IR detectors  

NASA Astrophysics Data System (ADS)

Bolometers are widely used as thermal detectors, e.g. in thermovision, medicine, astronomy etc. Among them there are thermistor-like devices consisting of the absorbing radiant power thermally sensitive films, deposited on the substrate. To meet the requirements made for bolometers, their material should have adequate parameters and characteristics. In this paper some thermal characteristics and parameters of the conducting, perovskite type ABO3 non-stoichiometric oxides LSCO and LSFO are discussed to evaluate their usefulness in the construction of bolometers.

Gorecki, Krzysztof; Stepowicz, Witold J.; Lozinski, Andrzej

2004-07-01

323

Interim procedure to measure the thermal performance of window systems  

SciTech Connect

The purpose of the report is to review the current sources of information on U-values and to describe the state of thermal test methods used for windows in order to provide the Bonneville Power Administration with some general guidelines in the application of thermal test data for use in the Model Conservation Standards (MCS) by the Northwest Power Planning Council. At present, considerable controversy exists in the window industry regarding the thermal testing of windows, therefore no consensus-based standards are available.

McCabe, M.E.; Goss, W.P.

1987-06-01

324

Performance of Thermal Insulation Containing Microencapsulated Phase Change Material  

SciTech Connect

The objective of this study is dynamic thermal performance microencapsulated phase change material (PCM) blended with loose-fill cellulose insulation. Dynamic hot-box testing and heat-flux measurements have been made for loose-fill cellulose insulation with and without uniformly distributed microencapsulated PCM. The heat flux measurements were made with a heat-flow-meter (HFM) apparatus built in accordance with ASTM C 518. Data were obtained for 1.6 lb{sub m}/ft{sup 3} cellulose insulation containing 0 to 40 wt% PCM. Heat-flux data resulting from a rapid increase in the temperature on one side of a test specimen initially at uniform temperature were analyzed to access the effect of PCM on total heat flow. The heat flux was affected by the PCM for about 100 minutes after the temperature increase. The total heat flow during this initial period decreased linearly with PCM content from 6.5 Btu/ft{sup 2} at 0% PCM to 0.89 Btu/ft{sup 2} for 40 wt% PCM. The cellulose insulation with PCM discharged heat faster than the untreated cellulose when the hot-side temperature of the test specimen was reduced. In addition, hot-box apparatus built in accordance with ASTM C 1363 was utilized for dynamic hot-box testing of a wood stud wall assembly containing PCM-enhanced cellulose insulation. Experimental data obtained for wood-frame wall cavities containing cellulose insulation with PCM was compared with results obtained from cavities containing only cellulose insulation.

Kosny, Jan [ORNL; Yarbrough, David [R & D Services; Syed, Azam M [ORNL

2007-01-01

325

Performance Assessment of Low Pressure Nuclear Thermal Propulsion.  

National Technical Information Service (NTIS)

A low pressure nuclear thermal propulsion (LPNTP) system, which takes advantage of hydrogen dissociation/recombination, was proposed as a means of increasing engine specific impulse (Isp). The effect of hydrogen dissociation/recombination on LPNTP Isp is ...

H. P. Gerrish G. E. Doughty

1993-01-01

326

Performance Assessment of Low Pressure Nuclear Thermal Propulsion.  

National Technical Information Service (NTIS)

An increase in Isp for nuclear thermal propulsion systems is desirable for reducing the propellant requirements and cost of future applications, such as the Mars Transfer Vehicle. Several previous design studies have suggested that the Isp could be increa...

H. P. Gerrish G. E. Doughty

1993-01-01

327

40 CFR 1037.140 - Curb weight and roof height.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Curb weight and roof height. 1037.140 Section 1037.140... § 1037.140 Curb weight and roof height. (a) Where applicable, a vehicle's curb weight and roof height are determined from nominal...

2013-07-01

328

Performance Comparison of Modular Photovoltaic-Thermal Solar Panels  

Microsoft Academic Search

The purpose of this experiment was to create a modular photovoltaic-thermal panel, which would be easily implemented and maintained. Three different prototype panels were tested simultaneously. The system was fixed at the optimal angle of 37.95° for the local area (Rolla, Missouri).The first two panels (Panel A & B) consisted of a highly conductive thermal sheeting and different sized copper

Nicole C. Annis; Stuart W. Baur

2011-01-01

329

Thermal performance of various multilayer insulation systems below 80K  

Microsoft Academic Search

The SSC collider dipole cryostat consists of a vacuum shell operating at room temperature, two thermal shields operating near 80K and 20K respectively, and the superconducting magnet assembly operating near 4K. The cryostat design incorporates multilayer insulation (MLI) blankets to limit radiant heat transfer into the 80K and 20K thermal shields. Also, an MLI blanket is used to impede heat

W. N. Boroski; T. H. Nicol; C. J. Schoo

1992-01-01

330

Roofing as a source of nonpoint water pollution  

Microsoft Academic Search

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 1.22m wide×3.66m long with a 25.8% roof slope. Thus, there were 32 alternatively arranged roofs, consisting of four roof types×two aspects×four

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

2004-01-01

331

Thermal performance of a photographic laboratory process: Solar Hot Water System  

NASA Astrophysics Data System (ADS)

The thermal performance of a solar process hot water system is described. The system was designed to supply 22,000 liters (5,500 gallons) per day of 66 C (150 F) process water for photographic processing. The 328 sq m (3,528 sq. ft.) solar field has supplied 58% of the thermal energy for the system. Techniques used for analyzing various thermal values are given. Load and performance factors and the resulting solar contribution are discussed.

Walker, J. A.; Jensen, R. N.

1982-04-01

332

New technology improves roof control safety  

Microsoft Academic Search

The US Bureau of Mines has designed roof bolters, supports, and roof-control systems that will increase mining productivity and efficiency while saving miner's lives. The author presents the results of ten of the Bureau's research projects that are related to ground control safety.

1985-01-01

333

Evaluation of Roof Trusses, Phase I.  

National Technical Information Service (NTIS)

The objective of this program was to evaluate a number of roof support systems that have some physical similarity to the truss introduced by the Birmingham Bolt Co. in 1966. The report is in two parts: Part I is a state-of-the-art study of roof truss tech...

C. P. Mangelsdorf

1979-01-01

334

SOUND TRANSMISSION LOSS OF GREEN ROOFS  

Microsoft Academic Search

Green roofs have the potential to provide excellent external\\/internal sound isolation due to their high mass, low stiffness and damping effect, and through surface absorption, reduce noise pollution in the community from aircraft, elevated transit systems, industrial sites and noise build-up in urban areas. This paper reviews the acoustical characteristics and the potential contributions of green roofs to the acoustical

Maureen Connelly; Murray Hodgson

335

Seismic qualification of building roof structure.  

National Technical Information Service (NTIS)

This paper presents a method for qualifying the existing roof structure of the Fuels and Materials Examination Facility (FMEF) at the US Department of Energy's Hanford Site in Richland, Washington. The roof is a safety class 1 structure and subject to the...

M. A. Islam R. B. Pan

1991-01-01

336

30 CFR 75.204 - Roof bolting.  

Code of Federal Regulations, 2010 CFR

...in an area of a coal mine with similar strata, opening dimensions and roof stresses...of the affected mine which has similar strata, opening dimensions and roof stresses...support by creating a beam of laminated strata shall be at least 30 inches long....

2010-07-01

337

Roofs--Their Problems and Solutions.  

ERIC Educational Resources Information Center

|Most roofs are meant to withstand the elements for a period of 20 years; to achieve this goal, however, school officials must believe in a dedicated maintenance program and sell it to their superiors and school boards. Establishment of a school district roof maintenance program is explained. Job qualifications and training methods for an inhouse…

Swentkofske, Carl J.

338

An Experimental Evaluation of Roof Reduction Factors.  

National Technical Information Service (NTIS)

A major portion of the radiation dose received within a structure is due to the fallout deposited on the roof. The report describes experiments conducted to measure the attenuation introduced by the roof to this radiation as a function of the mass thickne...

C. McDonnell J. Velletri

1966-01-01

339

Upgrade Piping Loads on Cleanroom Roof.  

National Technical Information Service (NTIS)

The proposed piping layout for the DO upgrade will run along the south wall of DAB. The cryogenic service pipe runs above the upper and lower cleanroom roofs and will need to be supported by the roofs' beams. Calculations were done to determine the stress...

S. Sakla

1995-01-01

340

Roofing Workbook and Tests. Plans and Specifications.  

ERIC Educational Resources Information Center

This combination workbook and set of tests on plans and specifications is one in a series of nine individually bound units of instruction for roofing apprenticeship classes. The five topics covered are (1) regulations governing the roofing and waterproofing industry, (2) an overview of blueprints, (3) an overview of specifications, (4)…

Mongerson, M. Duane, Comp.

341

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

SciTech Connect

Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal, potash, salt etc. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on such information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. A new mechanical approach to estimate rock strengths using the acquired drilling parameters has been proposed. This approach takes a number of important factors, that have never been studied in the previous researches, into the considerations. Good results have been shown using the new approach on the testing data.

Syd S. Peng

2002-01-15

342

Optimization and Thermal Performance Assessment of Pin-Fin Heat Sinks  

Microsoft Academic Search

In this work, the heat transfer and fluid flow analyses are employed to optimize the geometry of the pin-fin heat sinks. An entropy generation minimization method is employed to optimize the overall thermal performance and behavior of pin-fin heat sinks. The performance of the heat sinks is determined by its thermal resistance and pressure drop, since they significantly influence the

Z. S. Abdel-Rehim

2008-01-01

343

Performance of thermal-sprayed zinc anodes treated with humectants in cathodic protection systems  

Microsoft Academic Search

Thermal-sprayed Zn anodes are used for impressed current cathodic protection (ICCP) systems in Oregon's reinforced concrete coastal bridges to minimize corrosion damage. Thermal-sprayed Zn performs well as an ICCP anode but the voltage requirement can increase with increasing electrochemical age. It also performs well as a galvanic (GCP) anode but current output can decrease with increasing electrochemical age. Past research

Sophie J. Bullard; Covino Bernard S. Jr; Stephen D. Cramer; Gordon R. Holcomb; James H. Russell; John E. Bennett; John K. Milius; Curtis B. Cryer; Steven M. Soltesz

2001-01-01

344

Thermal budget simulations and device performance of microstructured high-Tc transition edge bolometers on silicon  

Microsoft Academic Search

Silicon represents the material of choice for fast superconducting high quality transition edge bolometers. The performance of these devices sensitively depends on their thermal properties where the heat flux critically affects time constant, optical response and noise behavior. In this work extensive numerical Finite Element-calculations have been performed for various bolometer configurations, using the ABAQUS-code. A high degree of thermal

M. Berg; J. Laukemper; H. Neff; E. Steinbeiss; W. Michalke; M. Burnus; T. Heidenblut

1995-01-01

345

Thermal Performance of Idealized Double Windows, Unvented. Research Paper No. 223.  

ERIC Educational Resources Information Center

The testing plans, procedures, and results of an experiment are revealed concerning the thermal performance and variable factors of unvented double windows, their heat transmission and inner surface temperature. Data are given to help improve the design and development of standards for the thermal performance of windows. Building humidity, window…

Christensen, G.; And Others

346

Thermal Performance Correlation of Horizontal Closed-Loop Oscillating Heat Pipes  

Microsoft Academic Search

The thermal performance of a closed-loop oscillating heat pipe which operates at horizontal orientation (Horizontal closed-loop oscillating heat pipe, HCLOHP) was dimensionally analyzed to formulate the empirical correlation. The various dimensionless groups which were supposed to influence the thermal performance of a HCLOHP was considered coupling with the quantitative results of the heat transfer characteristics of HCLOHP. These available results

Piyanun Charoensawan; Pradit Terdtoon

2007-01-01

347

Application of spatial frequency response as a criterion for evaluating thermal imaging camera performance  

Microsoft Academic Search

Police, firefighters, and emergency medical personnel are examples of first responders that are utilizing thermal imaging cameras in a very practical way every day. However, few performance metrics have been developed to assist first responders in evaluating the performance of thermal imaging technology. This paper describes one possible metric for evaluating spatial resolution using an application of Spatial Frequency Response

Andrew Lock; Francine Amon

2008-01-01

348

Thermal performance parameters estimation of hot box type solar cooker by using artificial neural network  

Microsoft Academic Search

Work to date has shown that Artificial Neural Network (ANN) has not been used for predicting thermal performance parameters of a solar cooker. The objective of this study is to predict thermal performance parameters such as absorber plate, enclosure air and pot water temperatures of the experimentally investigated box type solar cooker by using the ANN. Data set is obtained

Hüseyin Kurt; Kemal Atik; Mehmet Özkaymak; Ziyaddin Recebli

2008-01-01

349

Performance evaluation of a thermal Doppler Michelson interferometer system.  

PubMed

The thermal Doppler Michelson interferometer is the primary element of a proposed limb-viewing satellite instrument called SWIFT (Stratospheric Wind Interferometer for Transport studies). SWIFT is intended to measure stratospheric wind velocities in the altitude range of 15-45 km. SWIFT also uses narrowband tandem etalon filters made of germanium to select a line out of the thermal spectrum. The instrument uses the same technique of phase-stepping interferometry employed by the Wind Imaging Interferometer onboard the Upper Atmosphere Research Satellite. A thermal emission line of ozone near 9 microm is used to detect the Doppler shift due to winds. A test bed was set up for this instrument that included the Michelson interferometer and the etalon filters. For the test bed work, we investigate the behavior of individual components and their combination and report the results. PMID:16318186

Mani, Reza; Dobbie, Steven; Scott, Alan; Shepherd, Gordon; Gault, William; Brown, Stephen

2005-11-20

350

Alkali metal/halide thermal energy storage systems performance evaluation  

NASA Astrophysics Data System (ADS)

A pseudoheat-pipe heat transfer mechanism has been demonstrated effective in terms of both total heat removal efficiency and rate, on the one hand, and system isothermal characteristics, on the other, for solar thermal energy storage systems of the kind being contemplated for spacecraft. The selection of appropriate salt and alkali metal substances for the system renders it applicable to a wide temperature range. The rapid heat transfer rate obtainable makes possible the placing of the thermal energy storage system around the solar receiver canister, and the immersing of heat transfer fluid tubes in the phase change salt to obtain an isothermal heat source.

Phillips, W. M.; Stearns, J. W.

351

THE THERMAL 15 RELIEF WELL AND PRODUCTION PERFORMANCE OF THE THERMAL SHALLOW RESERVOIR  

SciTech Connect

Thermal 15 was drilled in November, 1983, to a TD of 700 feet. A steam entry encountered at 490 feet was found to communicate with the high-permeability upflow zone of the Thermal Shallow Reservoir. A low-flow-rate, higher-pressure steam entry at 600 feet was not detected while drilling but was indicated during a subsequent spinner survey. The pressure, flowrate, and enthalpy of the five wells completed in the upflow zone, including the Thermal 4 blowout, were monitored and recorded over a four month period before, during and after Thermal 15 was drilled. It was found that the Thermal 4 blowout communicates with the upflow zone of the Thermal Shallow Reservoir, the Thermal 4 flowrate is controlled by the shallow reservoir pressure, and the high permeability of the upflow zone allows such strong interference effects that three of the four commercial production wells will maximize production from this reservoir. A simple model was developed which describes the pressure-production characteristics of the reservoir over the normal range of operating conditions.

Mogen, P.; Maney, J.

1985-01-22

352

An analysis of moisture accumulation in the roof cavities of manufactured housing  

SciTech Connect

A detailed computer analysis is conducted to investigate whether moisture problems occur in the roof cavity of manufactured homes constructed in compliance with the current Department of Housing and Urban Development (HUD) Standards for manufactured housing. The current HUD Standards require a ceiling vapor retarder, but do not require outdoor ventilation of the roof cavity. In cold climates, the analysis revealed that moisture accumulates at lower roof surface and poses a risk of material degradation. The analysis found the following combination of passive measures to be effective in preventing detrimental winter moisture accumulation at lower surface of the roof: (1) providing a ceiling vapor retarder; (2) sealing penetrations and openings in the ceiling construction, and (3) providing natural ventilation openings in the roof cavity. In addition, the performance of a roof cavity exposed to a hot and humid climate is investigated. The analysis revealed that outdoor ventilation of the roof cavity causes the monthly mean relative humidity at the upper surface of the vapor retarder to exceed 80%. This condition is conducive to mold and mildew growth.

Burch, D. [NIST Building and Fire Research Lab., Gaithersburg, MD (United States). Building Environment Div.

1995-09-01

353

High-Performance Home Technologies: Solar Thermal & Photovoltaic Systems  

SciTech Connect

This document is the sixth volume of the Building America Best Practices Series. It presents information that is useful throughout the United States for enhancing the energy efficiency practices in the specific climate zones that are presented in the first five Best Practices volumes. It provides an introduction to current photovoltaic and solar thermal building practices. Information about window selection and shading is included.

Baechler, M.; Gilbride, T.; Ruiz, K.; Steward, H.; Love, P.

2007-06-01

354

Performance of different tungsten grades under transient thermal loads  

Microsoft Academic Search

Plasma facing components in future thermonuclear fusion devices will be subjected to intense transient thermal loads due to type I edge localized modes (ELMs), plasma disruptions, etc. To exclude irreversible damage to the divertor targets, local energy deposition must remain below the damage threshold for the selected wall materials. For monolithic tungsten (pure tungsten and tungsten alloys) power densities above

J. Linke; T. Loewenhoff; V. Massaut; G. Pintsuk; G. Ritz; M. Rödig; A. Schmidt; C. Thomser; I. Uytdenhouwen; V. Vasechko; M. Wirtz

2011-01-01

355

Optical and thermal performance of glazing with integral venetian blinds  

Microsoft Academic Search

Shading devices have long been used to control solar gain and daylighting through windows. The optimal design and use of such devices requires a detailed knowledge of their optical and thermal properties, including their variation with the angle of incidence of the solar radiation. We describe the experimental methods used to characterise two types of double-glazing units (DGU) incorporating Venetian

J. Breitenbach; S. Lart; I. Längle; J. L. J. Rosenfeld

2001-01-01

356

Performance of Thermal Barrier Coatings in High Heat Flux Environments.  

National Technical Information Service (NTIS)

Thermal barrier coatings were exposed to the high temperature and high heat flux produced by a 30 kW plasma torch. Analysis of the specimen heating rates indicates that the temperature drop across the thickness of the 0.038 cm ceramic layer was about 1100...

R. A. Miller C. C. Berndt

1984-01-01

357

Thermal Performance of the Exterior Envelopes of Buildings III: Proceedings.  

National Technical Information Service (NTIS)

This report is a collection of the proceedings of the ASHRAE/DOE/BTECC conference of December 2-5, 1985. The following general topics are covered: In-Situ Measurement of Energy Use; Microclimate and Design Weather Data; Air Infiltration; Thermal Analysis ...

1986-01-01

358

Duct thermal performance models for large commercial buildings  

Microsoft Academic Search

Despite the potential for significant energy savings by reducing duct leakage or other thermal losses from duct systems in large commercial buildings, California Title 24 has no provisions to credit energy-efficient duct systems in these buildings. A substantial reason is the lack of readily available simulation tools to demonstrate the energy-saving benefits associated with efficient duct systems in large commercial

Wray; Craig P

2003-01-01

359

Nuclear power plant thermal-hydraulic performance research program plan  

SciTech Connect

The purpose of this program plan is to present a more detailed description of the thermal-hydraulic research program than that provided in the NRC Five-Year Plan so that the research plan and objectives can be better understood and evaluated by the offices concerned. The plan is prepared by the Office of Nuclear Regulatory Research (RES) with input from the Office of Nuclear Reactor Regulation (NRR) and updated periodically. The plan covers the research sponsored by the Reactor and Plant Systems Branch and defines the major issues (related to thermal-hydraulic behavior in nuclear power plants) the NRC is seeking to resolve and provides plans for their resolution; relates the proposed research to these issues; defines the products needed to resolve these issues; provides a context that shows both the historical perspective and the relationship of individual projects to the overall objectives; and defines major interfaces with other disciplines (e.g., structural, risk, human factors, accident management, severe accident) needed for total resolution of some issues. This plan addresses the types of thermal-hydraulic transients that are normally considered in the regulatory process of licensing the current generation of light water reactors. This process is influenced by the regulatory requirements imposed by NRC and the consequent need for technical information that is supplied by RES through its contractors. Thus, most contractor programmatic work is administered by RES. Regulatory requirements involve the normal review of industry analyses of design basis accidents, as well as the understanding of abnormal occurrences in operating reactors. Since such transients often involve complex thermal-hydraulic interactions, a well-planned thermal-hydraulic research plan is needed.

Not Available

1988-07-01

360

Magnet cold mass high load supports thermal response and performance design correlation  

SciTech Connect

Through General Dynamics Convair Division's experience in the design, detail analysis, and manufacturing of structural supports for superconducting magnet cryostats suspended in a vacuum enclosure, a data base, well suited for the development of correlations of pertinent thermal performance criteria for stainless steel supports, has been created. The thermal requirements of these supports in fusion applications are well defined for the Mirror Fusion Test Facility (MFTF) and have been analyzed in detail for cool-down response and steady-state performance, using Convair's THERMAL ANALYZER computer program. From the output of these thermal conditioning simulations, correlations were developed for magnet LHe heating from supports in terms of strut geometric parameters.

Jones, G.R.; Christensen, E.H.

1984-09-01

361

Integrated analysis of nuclear thermal rocket system performance  

Microsoft Academic Search

As part of the Space Exploration Initiative (SEI), nuclear thermal rocket (NTR) engines will play a key transportation role. Although a number of tests of prismatic, solid-core nuclear engines were completed during the ROVER\\/NERVA program, the estimated cost of completing full-engine tests will severely limit the scope, duration, and number of any such tests in the future. Design optimization by

J. J. Buksa; W. J. Rider; M. Hall; R. T. Perry; M. Houts

1992-01-01

362

High-Performance Home Technologies: Solar Thermal & Photovoltaic Systems  

NSDL National Science Digital Library

The Advanced Technology Environmental and Energy Center (ATEEC) provides this document, which was created by the U.S. Department of Energy, on solar thermal and photovoltaic systems. In addition to providing a general overview of these energy technologies, the document also includes a number of useful case studies highlighting construction projects which use energy efficient methods and equipment. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

2012-07-10

363

Room temperature soldering of microelectronic components for enhanced thermal performance  

Microsoft Academic Search

A novel fluxless soldering process is presented, that enables lead-free soldering of semiconductor die-to-heat spreader (and heat spreader-to-heat sink structures) at room temperature. The process is based on the use of reactive multilayer foils to locally melt the solder interface. Silicon-copper samples joined with indium solder are thermally characterized for a range of die sizes and bond line thicknesses. The

J. S. Subramanian; P. Rodgers; J. Newson; T. Rude; Z. He; E. Besnoin; T. P. Weihs; V. Eveloy; M. Pecht

2005-01-01

364

Piston Assembly Design for Improved Thermal-Tribological Performance  

Microsoft Academic Search

The tribological system in the piston assembly of an internal combustion engine includes contacts at interfaces of piston\\/piston ring\\/cylinder liner, piston skirt\\/cylinder wall, and piston\\/piston pin\\/ connecting rod. The thermal and tribological properties of the piston, piston rings, and cylinder wall are critical to the life and quality of the engine. Severe wear and scuffing failure, especially at the ring\\/ring

Qian Wang; Yiding Cao; Gang Chen

1996-01-01

365

Integrated modeling of nuclear thermal rocket system safety and performance  

SciTech Connect

The Advanced Nuclear Thermal Rocket Engine Simulator (ANTARES) environment, which consistes of an overall architecture employing state-of-the-art computer hardware and an integrated physics simulation nucleus is presented. The ANTARES architecture is described, and its benefits are outlined. In an attempt to demonstrate the fidelity and ability of the physics simulator, a coupled physics methodology for use in simulating design basis accidents is presented. A preliminary high-resolution, heat-transfer model for use in ANTARES is also presented.

Buksa, J.J.; Rider, W.J.; Hall, M.L. (Los Alamos National Laboratory, Reactor Design and Analysis Group, Los Alamos National Laboratory, Los Alamos, NM 87544 (United States))

1993-01-20

366

Ballistic performance of porous-ceramic, thermal protection systems  

NASA Astrophysics Data System (ADS)

Porous-ceramic, thermal protection systems are used heavily in current reentry vehicles like the Orbiter, and they are currently being proposed for the next generation of US manned spacecraft, Orion. These systems insulate reentry critical components of a spacecraft against the intense thermal environments of atmospheric reentry. Additionally, these materials are highly exposed to space environment hazards like solid particle impacts. This paper discusses impact studies up to 10 km/s on 8 lb/ft3 alumina-fiber-enhanced-thermal-barrier (AETB8) tiles coated with a toughened-unipiece-fibrousinsulation/ reaction-cured-glass layer (TUFI/RCG). A semi-empirical, first principles impact model that describes projectile dispersion is described that provides excellent agreement with observations over a broad range of impact velocities, obliquities and projectile materials. Model extensions to look at the implications of greater than 10 GPa equation of state is also discussed. Predicted penetration probabilities for a vehicle visiting the International Space Station is 60% lower for orbital debris and 95% lower for meteoroids with this model compared to an energy scaled approach.

Miller, Joshua E.; Bohl, William E.; Christiansen, Eric C.; Davis, Bruce A.; Foreman, Cory D.

2012-03-01

367

Ballistic Performance of Porous-Ceramic, Thermal Protection Systems  

NASA Astrophysics Data System (ADS)

Porous-ceramic, thermal protection systems are used heavily in current reentry vehicles like the Orbiter, and they are currently being proposed for the next generation of US manned spacecraft, Orion. These systems insulate reentry critical components of a spacecraft against the intense thermal environments of atmospheric reentry. Additionally, these materials are also highly exposed to space environment hazards like solid particle impacts. This paper discusses impact testing up to 9.65 km/s on one of these systems. The materials considered are 8 lb/ft^3 alumina-fiber-enhanced-thermal-barrier (AETB8) tiles coated with a toughened-unipiece-fibrous-insulation/reaction-cured-glass layer (TUFI/RCG). A semi-empirical, first principals impact model that describes projectile dispersion is described that provides excellent agreement with observations over a broad range of impact velocities, obliquities and projectile materials. A model extension to look at the implications of greater than 10 GPa equation of state measurements is also discussed. Predicted penetration probabilities for a vehicle visiting the International Space Station is 60% lower for orbital debris and 95% lower for meteoroids with this model compared to an energy scaled approach.

Miller, Joshua; Bohl, William; Christiansen, Eric; Davis, B. Alan; Foreman, Cory

2011-06-01

368

Development of thermal performance criteria for residential passive solar buildings. Final report  

SciTech Connect

In support of the development of thermal performance criteria for residential passive solar buildings, thermal design characteristics and anticipated performance for 266 projects in the HUD Passive Residential Design Competition and the HUD Cycle 5 Demonstration Program were analyzed. A number of performance measures were examined, including net solar contribution, solar fraction, and auxiliary energy use. These and other design and climate-related parameters were statistically correlated using the DATAPLOT computer program and standard statistical analysis techniques.

Sabatiuk, P.A.; McCabe, M.

1980-10-01

369

Thermal performance of sub-atmospheric loop thermosyphon with and without enhanced boiling surface  

Microsoft Academic Search

This experimental study comparatively examines the thermal performances of two-phase loop thermosyphons (TPLP) with and without enhanced boiling surface at sub-atmospheric pressures. The boiling instabilities along with the constituent and total thermal resistances of these TPLPs are analyzed with the aid of boiling flow structures imaged at sub-atmospheric pressures. Boiling heat flux (Q) and thermal resistance of condenser (Rth,con) are

S. W. Chang; K. F. Chiang; C.-C. Huang

2012-01-01

370

Solar thermal absorption heat pump breakeven coefficient of performance  

Microsoft Academic Search

This paper compares the performance of direct solar heating with heating obtained with solar energy amplified through an absorption heat pump. It is shown that if the performance of the two systems is to be at least equal under similar operating conditions, the absorption heat pump must have a minimum heating coefficient of performance (COP)H, which is defined as the

M. Balasubramaniam; G. L. Schrenk; A. Lowi; J. C. Denton

1974-01-01

371

Thermal sensitivity of metabolic rates and swimming performance in two latitudinally separated populations of cod, Gadus morhua L  

Microsoft Academic Search

Atlantic cod populations live in a wide thermal range and can differ genetically and physiologically. Thermal sensitivity\\u000a of metabolic capacity and swimming performance may vary along a latitudinal gradient, to facilitate performance in distinct\\u000a thermal environments. To evaluate this hypothesis, we compared the thermal sensitivity of performance in two cod stocks from\\u000a the Northwest Atlantic that differ in their thermal

Eve-Lyne Sylvestre; Dominique Lapointe; Jean-Denis Dutil; Helga Guderley

2007-01-01

372

Laboratory measurements of the drying rates of low-slope roofing systems  

SciTech Connect

The service life of a roofing system typically ends when excessive amounts of water have entered the system. Roofing professionals determine whether the existing failed roofing system can be repaired or salvaged by recovering. A key element in this decision is whether the accumulated water will be able to leave the roofing system in a time frame that will prevent irreparable structural damage. There are several combined heat and mass transfer models that can be used to predict drying times for low-slope roofing systems. Very little experimental data exists that can be used to validate the performance of these models. To satisfy these needs, a series of laboratory experiments has been performed. Five test panels, comprised of a plywood deck, four types of roofing insulation, and a single ply membrane were installed in a climate simulator. The test panels were outfitted with temperature sensors and heat flux transducers, and were mounted on load cells. Water was added to the test panels and they were subjected to external diurnal cycles representative of summer and winter conditions for a southern US continental climate. The load cells supplied continuous records of the weights of the test panels; these data were used to compute the drying rates of the test panels. When these experiments were completed, the test panels were ``recovered`` with different thicknesses of insulation and the environmental conditions were reapplied to the test panels. This paper reports on the design and performance of these experiments. The data compiled during these tests supply insight into the effects of meteorological conditions, insulation R-value, insulation water vapor permeance, and roof recover on the rate that water will be removed from low-slope roofing systems.

Desjarlais, A.O.; Kyle, D.M.; Childs, P.W.; Christian, J.E.

1994-05-01

373

24 CFR 3280.402 - Test procedure for roof trusses.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Test procedure for roof trusses. 3280.402 Section 3280.402 ...3280.402 Test procedure for roof trusses. (a) Roof load tests. The following...provisions of § 3280.401, for roof trusses that are supported at the ends and...

2009-04-01

374

24 CFR 3280.402 - Test procedure for roof trusses.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Test procedure for roof trusses. 3280.402 Section 3280.402 ...3280.402 Test procedure for roof trusses. (a) Roof load tests. The following...provisions of § 3280.401, for roof trusses that are supported at the ends and...

2010-04-01

375

Green roofs as a means of pollution abatement  

Microsoft Academic Search

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,

D. Bradley Rowe

2011-01-01

376

GREEN COOLING: COMBINING VEGETATED ROOFS WITH NIGHT VENTILATION  

Microsoft Academic Search

This paper describes the effects of green roofs and night ventilation on internal temperature of buildings using test cells with different configurations. Three cells are used in these tests, all of them cooled with night ventilation, one with an insulated green roof, another with an uninsulated green roof and another with a conventional code compliant insulated roof. Several series are

Pablo La Roche

377

Millikelvin thermal and electrical performance of lossy transmission line filters  

SciTech Connect

We report on the scattering parameters and Johnson noise emission of low-pass stripline filters employing a magnetically loaded silicone dielectric down to 25 mK. The transmission characteristic of a device with f-3dB=1.3 GHz remains essentially unchanged upon cooling. Another device with f-edB=0.4 GHz, measured in its stopband, exhibits a steady state noise power emission consistent with a temperature difference of a few mK relative to a well-anchored cryogenic microwave attenuator at temperatures down to 25 mK, thus presenting a matched thermal load.

Slichter, Daniel; Naaman, Ofer; Siddiqi, Irfan

2009-03-11

378

Modelling the thermal performance of earth-to-air heat exchangers  

Microsoft Academic Search

A new complete numerical model for the prediction of thermal performance of the earth-to-air heat exchangers is presented. The model describes the simultaneous heat and mass transfer inside the tube and into the soil accounting for the soil natural thermal stratification. The model is validated against an extensive set of experimental data and it is found accurate. The proposed algorithms

G. Mihalakakou; M. Santamouris; D. Asimakopoulos

1994-01-01

379

Improving accuracy and flexibility of ASTM D 5470 for high performance thermal interface materials  

Microsoft Academic Search

The thermal demands of current and next generation microprocessors have driven requirements for thermal interface materials (TIMs) to the point where reliable vendor data is often not available. Vendors are struggling to meet customers needs. Existing industry test standards were intended for electrical insulation materials and cannot provide accurate data for todays high performance TIMs. Manufacturers are forced to accept

D. Kearns

2003-01-01

380

The experimental investigation on thermal performance of a flat two-phase thermosyphon  

Microsoft Academic Search

Electronics cooling has become a key factor for improving the performance of electronic devices. An effective thermal spreader can achieve a more uniform heat flux distribution and thus increase heat dissipation in heat sinks. Two-phase thermosyphon is highly effective thermal spreader. In order to observe boiling and condensation phenomena, a transparent two-phase thermosyphon was prepared for observation and study. The

Ming Zhang; Zhongliang Liu; Guoyuan Ma

2008-01-01

381

The decremented average ground-temperature method for predicting the thermal performance of underground walls  

Microsoft Academic Search

At present, the only accurate method for predicting the thermal performance of underground structures is through the use of large computer models and finite difference equations. Due to the prohibitively high cost of setting up and running these computer models, thermal analysis of subsurface buildings is inaccessible to many prospective users. The existing manual methods for calculating loads on underground

J. M. Ackridge; J. F. J. Poulos

1983-01-01

382

Thermal performance of a latent heat energy storage ventilated panel for electric load management  

Microsoft Academic Search

A theoretical study was conducted to assess the thermal performance of a ventilated panel heating unit. The unit employs the latent heat energy storage method to level the electrical energy demand for domestic space heating during peak hours. A one-dimensional, semi-empirical model was developed to predict the dynamic thermal behavior of the storage unit under cyclic melting and solidification. The

A. Laouadi; M. Lacroix

1999-01-01

383

5CM, No Iron SSC Dipole 12M Model Cryostat Thermal Performance.  

National Technical Information Service (NTIS)

A 12 m long model of a 5 cm costheta dipole cryostat has been constructed and its thermal performance measured. The model utilized heat intercepted fiberglass reinforced plastic posts to support the 12 m long, 4.5 K cold mass and the 10 and 80 K thermal s...

A. Szymulanski J. Otavka J. D. Gonczy R. C. Niemann R. J. Powers

1985-01-01

384

An experimental investigation of the thermal performance of an asymmetrical flat plate heat pipe  

Microsoft Academic Search

An experimental investigation of the thermal performance of a flat plate heat pipe is presented in this work. The results indicate that the temperature along the heat pipe wall surfaces is quite uniform. The results also indicate that the porous wick of the evaporator section creates the main thermal resistance resulting in the largest temperature drop, which consequently affects the

Y. Wang; K. Vafai

2000-01-01

385

Assessment of thermal performance of different types of masonry bricks used in Saudi Arabia  

Microsoft Academic Search

This paper presents the assessment of thermal performance of nine types of clay brick and two types of concrete brick in use in Saudi Arabia. The results are based on the experimentally measured values of equivalent thermal conductivity. The analysis of the measured data showed that the addition of insulation material either within the masonry brick mix to make the

Luai M. Al-Hadhrami; A. Ahmad

2009-01-01

386

Energy and comfort performance of thermally activated building systems including occupant behavior  

Microsoft Academic Search

In building simulations it is common practice to use standardized occupant behavior and internal gains. Although this is a valid approach for designing systems, the probabilistic nature of these boundary conditions influences the energy demand and achieved thermal comfort of real systems. This paper analyzes the influence of occupant behavior on the energy performance and thermal comfort of a typical

Dirk Saelens; Wout Parys; Ruben Baetens

2011-01-01

387

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

Microsoft Academic Search

Copper sheeting is a common roofing material used in many parts of the world. However, copper dissolved from roof sheeting\\u000a represents a source of copper ions to watersheds. Researchers have studied and recently developed a simple and efficient model\\u000a to predict copper runoff rates. Important input parameters include precipitation amount, rain pH, and roof angle. We hypothesized\\u000a that the length

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

388

Performance of different tungsten grades under transient thermal loads  

NASA Astrophysics Data System (ADS)

Plasma facing components in future thermonuclear fusion devices will be subjected to intense transient thermal loads due to type I edge localized modes (ELMs), plasma disruptions, etc. To exclude irreversible damage to the divertor targets, local energy deposition must remain below the damage threshold for the selected wall materials. For monolithic tungsten (pure tungsten and tungsten alloys) power densities above ?0.3 GW m-2 with 1 ms duration result in the formation of a dense crack network. Thin tungsten coatings for the so-called ITER-like wall in JET, which have been deposited on a two-directional carbon-fibre composite (CFC) material, are even less resistant to thermal shock damage; here the threshold values are by a factor of 2 lower. First ELM-simulation experiments with high cycle numbers up to 104 cycles on actively cooled bulk tungsten targets do not reveal any cracks for absorbed power densities up to 0.2 GW m-2 and ELM-durations in the sub-millisecond range (0.8 ms); at somewhat higher power densities (0.27 GW m-2, ?t = 0.5 ms) cracks have been detected for 106 cycles.

Linke, J.; Loewenhoff, T.; Massaut, V.; Pintsuk, G.; Ritz, G.; Rödig, M.; Schmidt, A.; Thomser, C.; Uytdenhouwen, I.; Vasechko, V.; Wirtz, M.

2011-07-01

389

Stationary DIANE equipment Description and performance of the thermal neutron source  

NASA Astrophysics Data System (ADS)

A new neutron radiography facility using a GENIE 46 generator is now operating at SODERN (France). In contrast to the first mobile DIANE system working at IABG (Germany), this new version uses a stationary thermal neutron source. With this second equipment the performance has been significantly improved. Thanks to computer simulations and experimental thermal neutron cartography, progress has been made on neutron moderation/thermalization (combination of lead and HD polyethylene), extraction geometry, neutron and photon collimation. The results in terms of gamma ray and thermal neutron contents in the beam are reported.

Cluzeau, S.; Le Tourneur, P.

1994-05-01

390

The Envelope Thermal Test Unit (ETTU): Full Measurement of WallPerform ance  

SciTech Connect

There are many ways of calculating the dynamic thermal performance of walls and many ways of measuring the performance of walls in the laboratory, relatively few field measurements have been made of the dynamic performance of wall in situ. Measuring the thermal performance of walls in situ poses two separate problems: measuring the heat fluxes and surface temperatures of the wall, and reducing this data set into usable parameters. We have solved the first problem by developing the Envelope Thermal Test Unit (ETTU). ETTU consists of two specially constructed polystyrene blankets, 1.2m square, placed on either side of the test wall that both control and measure the surface fluxes and surface temperatures of the wall. To solve the second problem we have developed a simplified dynamic model that describes the thermal performance of a wall in terms of its steady-state conductance, a time constant, and some storage terms. We have used ETTU in the field to measure the thermal performance of walls, and have applied our simplified analysis to calculate simplified thermal parameters from this data set. In this report, we present the in-situ measurements made to date using ETTU, and the resulting model predictions. The agreement between measured and predicted surface fluxes demonstrates the ability of our test unit and analytic model to describe the dynamic performance of walls in situ.

Sonderegger, R.C.; Sherman, M.H.; Adams, J.W.

1981-10-01

391

Indoor Test for Thermal Performance Evaluation of the Northrup Concentrating Solar Collector.  

National Technical Information Service (NTIS)

The test procedure used and the results obtained from an evaluation test program conducted to obtain thermal performance data on a Northrup concentrating solar collector under simulated conditions are described. These tests were made using the Marshall Sp...

1978-01-01

392

System and Method for Estimating Performance of a Closed Cycle Thermal Propulsion System.  

National Technical Information Service (NTIS)

The present invent ion permits determination of steady-state off- design performance characteristics of a vehicle, such as a torpedo, powered by a closed cycle thermal propulsion system. The method may be utilized to determine propellant consumption for a...

W. A. Girouard

2002-01-01

393

TOD Versus MRT When Evaluating Thermal Imagers that Exhibit Dynamic Performance.  

National Technical Information Service (NTIS)

While it is universally recognized that image quality of a thermal sensor is a strong function of spatial uniformity, the metrics commonly used to assess performance do not adequately measure the effectiveness of non- uniformity correction (NUC). Image un...

J. Graff J. Kostrzewa J. Long J. D. Vincent

2003-01-01

394

Hypothetical Reentry Thermostructural Performance of Space Shuttle Orbiter With Missing or Eroded Thermal Protection Tiles.  

National Technical Information Service (NTIS)

This report deals with hypothetical reentry thermostructural performance of the Space Shuttle orbiter with missing or eroded thermal protection system (TPS) tiles. The original STS-5 heating (normal transition at 1100 sec) and the modified STS-5 heating (...

W. L. Ko L. Gong R. D. Quinn

2004-01-01

395

Plant Species and Functional Group Combinations Affect Green Roof Ecosystem Functions  

PubMed Central

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 facilitation as mechanisms governing biodiversity-ecosystem functioning relationships in green roof ecosystems.

Lundholm, Jeremy; MacIvor, J. Scott; MacDougall, Zachary; Ranalli, Melissa

2010-01-01

396

Thermal performance of a pin-fin assembly  

NASA Astrophysics Data System (ADS)

The steady-state forced-convective cooling of a horizontally based pin-fin assembly has been investigated experimentally. The circular pin-fins protruded vertically upward from a horizontal base plate. For each in-line or staggered combination of specified pin-fins and air-flow rate, the optimal spacing-to-diameter ratios corresponding to the maximum rate of heat dissipation from the array have been deduced. The effect of changing the thermal conductivity of the pin-fin material has been studied. Designers should aim to have a spacing-to-diameter ratio of 1.04, in the span-wise direction, for all pin-fin systems; whereas, the ratio for the pin-fins in the stream-wise direction will depend upon what fin material is used and whether or not the pin-fins are staggered or aligned.

Babus'hag, R. F.; Akintunde, K.; Probert, S. D.

1995-02-01

397

Thermal performance of heat pipe with suspended nano-particles  

NASA Astrophysics Data System (ADS)

Nanofluids are employed as the working medium for a conventional cylindrical heat pipe. A cylindrical copper heat pipe of 19.5 mm outer diameter and 400 mm length was fabricated and tested with two different working fluids. The working fluids used in this study are DI-water and Nano-particles suspension (mixture of copper nano particle and DI-water). The overall heat transfer coefficient of the heat pipe was calculated based on the lumped thermal resistance network and compared with the heat transfer coefficient of base fluid filled heat pipe. There is a quantitative improvement in the heat transfer coefficient using nano-particles suspension as the working medium. A heat transfer correlation was also developed based on multiple regression least square method and the results were compared with that obtained by the experiment.

Shukla, K. N.; Solomon, A. Brusly; Pillai, B. C.; Ruba Singh, B. Jacob; Saravana Kumar, S.

2012-11-01

398

Performance Testing of Thermal Cutting Systems for Sweet Pepper Harvesting Robot in Greenhouse Horticulture  

NASA Astrophysics Data System (ADS)

This paper proposes design of end-effector and prototype of thermal cutting system for harvesting sweet peppers. The design consists of two parallel gripper bars mounted on a frame connected by specially designed notch plate and operated by servo motor. Based on voltage and current, two different types of thermal cutting system prototypes; electric arc and temperature arc respectively were developed and tested for performance. In electric arc, a special electric device was developed to obtain high voltage to perform cutting operation. At higher voltage, electrodes generate thermal arc which helps to cut stem of sweet pepper. In temperature arc, nichrome wire was mounted between two electrodes and current was provided directly to electrodes which results in generation of high temperature arc between two electrodes that help to perform cutting operation. In both prototypes, diameters of basic elements were varied and the effect of this variation on cutting operation was investigated. The temperature arc thermal system was found significantly suitable for cutting operation than electric arc thermal system. In temperature arc thermal cutting system, 0.5 mm nichrome wire shows significant results by accomplishing harvesting operation in 1.5 seconds. Also, thermal cutting system found suitable to increase shelf life of fruits by avoiding virus and fungal transformation during cutting process and sealing the fruit stem. The harvested sweet peppers by thermal cutting system can be preserved at normal room temperature for more than 15 days without any contamination.

Bachche, Shivaji; Oka, Koichi

2013-03-01

399

The performance analysis of the Trough Concentrating Solar Photovoltaic\\/Thermal system  

Microsoft Academic Search

The electrical and thermal performance of a 2m2 Trough Concentrating Photovoltaic\\/Thermal (TCPV\\/T) system with an energy flux ratio 10.27 are characterized by experiments. A single crystalline silicon solar cell array, a polycrystalline silicon cell array, a Super cell array and a GaAs cell array are respectively used in the experiments. The experimental results show that the electrical performance of the

M. Li; G. L. Li; X. Ji; F. Yin; L. Xu

2011-01-01

400

Thermal performance of a thin high interconnect density organic substrate for flip-chip applications  

Microsoft Academic Search

The thermal performance of a thin (0.5 mm), high interconnect density substrate for flip-chip applications (FC-PBGA) has been studied under natural and forced convection conditions per JEDEC standard conditions [1999]. Since the effect of a heat sink not considered, heat conduction within the package and substrate is relatively more important to thermal performance. A package size of 42.5 mm is

Varaprasad V. Calmidi

2005-01-01

401

Introduction to the Third International Workshop on Long-Term Thermal Performance of Cellular Plastic Insulation  

Microsoft Academic Search

Methodology for the evaluation of long-term thermal performance of cellular plastics is being developed under a collaboration of North American foam industry with the National Research Council of Canada. The mechanism of this col laboration includes a joint research project between the Society of Plastics Industry and the NRC Canada.To evaluate long-term thermal performance (LTTP) of cellular plastics the aging

Mark Bomberg; Kumar Kumaran

1993-01-01

402

Stenotherms at sub-zero temperatures: thermal dependence of swimming performance in Antarctic fish  

Microsoft Academic Search

We examined the burst swimming performance of two Antarctic fishes, Trematomus bernacchii and T. centronotus, at five temperatures between -1°C and 10°C. As Antarctic fishes are considered one of the most cold specialised and stenothermal of all ectotherms, we predicted they would possess a narrow thermal performance breadth for burst swimming and a correlative decrease in performance at high temperatures.

Robbie S. Wilson; Craig E. Franklin; William Davison; Peter Kraft

2001-01-01

403

Differential thermal performance curves in response to different habitats in the parasitoid Venturia canescens  

NASA Astrophysics Data System (ADS)

Environmental variability is expected to be important in shaping performance curves, reaction norms of phenotypic traits related to fitness. Models predict that the breadth of performance curves should increase with environmental variability at the expense of maximal performance. In this study, we compared the thermal performance curves of two sympatric populations of the parasitoid Venturia canescens that were observed under contrasting thermal regimes in their respective preferred habitats and differing in their modes of reproduction. Our results confirm the large effect of developmental temperature on phenotypic traits of insects and demonstrate that thelytokous and arrhenotokous wasps respond differently to temperature during development, in agreement with model predictions. For traits related to fecundity, thelytokous parasitoids, which usually occur in stable thermal conditions, exhibit specialist performance curves, maximising their reproductive success under a restricted range of temperature. In contrast, arrhenotokous parasitoids, which occur in variable climates, exhibit generalist performance curves, in keeping with the hypothesis "jack of all temperatures, master of none".

Foray, Vincent; Gibert, Patricia; Desouhant, Emmanuel

2011-08-01

404

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

SciTech Connect

In this quarter, the field, theoretical and programming works have been performed toward achieving the research goals set in the proposal. The main accomplishments in this quarter included: (1) two more sets of field tests have been conducted in an underground coal mine, (2) optimization studies of the control parameters have been conducted, (3) method to use torque to thrust ratio as indicator of rock relative hardness has also been explored, and (3) about 97% of the development work for the roof geology mapping program, MRGIS, has completed, (4) A special version of the geology mapping program for a limestone mine has been developed. The field test for the software and hardware has been successfully finished.

Syd S. Peng

2004-09-15

405

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

SciTech Connect

A one-year non-cost extension has been granted for this project. In this quarter, the field, theoretical and programming works have been performed toward achieving the research goals set in the proposal. The main accomplishments in this quarter included: (1) laboratory tests have been conducted, (2) with the added trendline analysis method, the accuracy of the data interpretation methodology will be improved and the interfaces and voids can be more reliably detected, (3) method to use torque to thrust ratio as indicator of rock relative hardness has also been explored, and (3) about 80% of the development work for the roof geology mapping program, MRGIS, has completed and a special version of the program is in the field testing stage.

Syd S. Peng

2004-04-15

406

Performance assessment of low pressure nuclear thermal propulsion  

NASA Astrophysics Data System (ADS)

A low pressure nuclear thermal propulsion (LPNTP) system, which takes advantage of hydrogen dissociation/recombination, was proposed as a means of increasing engine specific impulse (Isp). The effect of hydrogen dissociation/recombination on LPNTP Isp is examined. A two-dimensional computer model was used to show that the optimum chamber pressure is approximately 100 psia (at a chamber temperature of 3,000 K), with an Isp approximately 15 s higher than at 1,000 psia. At high chamber temperatures and low chamber pressures, the increase in Isp is due to both lower average molecular weights caused by dissociation and added kinetic energy from monatomic hydrogen recombination. Monatomic hydrogen recombination increases the Isp more then hydrogen dissociation. Variations in the mole fraction of monatomic hydrogen are similar to variations in static pressure along the axial nozzle position. Most recombination occurs close to the nozzle throat. Practical variations in nozzle geometry have minimal impact on recombination. Other models which can simulate a wider range of nozzle designs should be used in the future. The uncertainty of the hydrogen kinetic reaction rates at high temperatures (approximately 3,000 K) affects the accuracy of the analysis and should be verified with simple bench tests.

Gerrish, H. P., Jr.; Doughty, G. E.

1993-12-01

407

Synthesized performance model of thermal imaging systems based on natural background  

NASA Astrophysics Data System (ADS)

The impact of nature environment on the synthesized performance of thermal imaging systems was researched comparing with the targeting task performance (TTP) model. A nature background noise factor was presented and introduced into the minimum resolvable temperature difference channel width (MRTD-CW) model. The method for determining the nature background noise factor was given. A information quantity model based on MRTD-CW model was proposed to evaluate the impact of nature environment on the synthesized performance of thermal imaging systems. A normalized parameter was introduced into the information quantity model. Different background experiments were performed, and the results were analyzed and compared with those of TTP model.

Chen, Song-lin; Wang, Ji-hui; Wang, Xiao-wei; Jin, Wei-qi

2013-09-01

408

Measured Energy Savings from the Application of Reflective Roofs in 3 AT and T Regeneration Buildings  

SciTech Connect

Energy use and environmental parameters were monitored in three AT and T regeneration buildings during the summer of 2000. These buildings are constructed with concrete and are about 14.9 m2 (160 f2; 10x16 ft)in size. The buildings were initially monitored for about 1 1/2 months to establish a base condition. Then, the roofs of the buildings were painted with a white coating and the monitoring was continued. The original roof reflectances were about 26 percent; after the application of roof coatings the reflectivities increased to about 72 percent. In two of these buildings, we monitored savings of about 0.5kWh per day (8.6 kWh/m2 [0.8 kWh/ft2]). The third building showed a reduction in air-conditioning energy use of about 13kWh per day. These savings probably resulted from the differences in the performance (EER) of the two dissimilar AC units in this building. The estimated annual savings for two of the buildings are about 125kWh per year; at a cost of dollar 0.1/kWh, savings are about dollar 12.5 per year. Obviously, it costs significantly more than this amount to coat the roofs with reflective coating, particularly because of the remote location of the buildings. However, since the prefabricated roofs are already painted green at the factory, painting them with white (reflective) color would bring no additional cost. Hence the payback time for having reflective roofs is nil, and the reflective roofs save an accumulated 370kWh over 30 years of the life of the roof.

Akbari, Hashen; Rainer, Leo

2000-11-01

409

Performance of thermal-sprayed zinc anodes treated with humectants in cathodic protection systems  

SciTech Connect

Thermal-sprayed Zn anodes are used for impressed current cathodic protection (ICCP) systems in Oregon's reinforced concrete coastal bridges to minimize corrosion damage. Thermal-sprayed Zn performs well as an ICCP anode but the voltage requirement can increase with increasing electrochemical age. It also performs well as a galvanic (GCP) anode but current output can decrease with increasing electrochemical age. Past research has shown that increasing moisture at the Zn anode-concrete interface improves the operation of the thermal-sprayed Zn anode. Humectants, hygroscopic materials that are applied to the surface of the Zn-anode, can increase the moisture at the zinc-concrete interface, thereby improving the performance and extending the anode service life. Results are given for humectant-treated (LiBr and LiNO3) thermal-sprayed Zn anodes used in the laboratory electrochemical aging studies and in field studies on the Yaquina Bay Bridge, Oregon, USA.

Bullard, Sophie J.; Covino, Bernard S., Jr.; Cramer, Stephen D.; Holcomb, Gordon R.; Russell, James H.; Bennett, John E. (JE Bennett Consulting Inc.); Milius, John K. (Corrosion Restoration Tech.); Cryer, Curtis B. (Oregon Dept. of Transportation); Soltesz, Steven M. (Oregon Dept. of Transportation)

2001-01-01

410

Thermal Performance Comparison of Glass Microsphere and Perlite Insulation Systems for Liquid Hydrogen Storage Tanks  

NASA Astrophysics Data System (ADS)

A technology demonstration test project was conducted by the Cryogenics Test Laboratory at the Kennedy Space Center (KSC) to provide comparative thermal performance data for glass microspheres, referred to as bubbles, and perlite insulation for liquid hydrogen tank applications. Two identical 1/15th scale versions of the 3,200,000 liter spherical liquid hydrogen tanks at Launch Complex 39 at KSC were custom designed and built to serve as test articles for this test project. Evaporative (boil-off) calorimeter test protocols, including liquid nitrogen and liquid hydrogen, were established to provide tank test conditions characteristic of the large storage tanks that support the Space Shuttle launch operations. This paper provides comparative thermal performance test results for bubbles and perlite for a wide range of conditions. Thermal performance as a function of cryogenic commodity (nitrogen and hydrogen), vacuum pressure, insulation fill level, tank liquid level, and thermal cycles will be presented.

Sass, J. P.; Fesmire, J. E.; Nagy, Z. F.; Sojourner, S. J.; Morris, D. L.; Augustynowicz, S. D.

2008-03-01

411

Performance evaluation of solar thermal electric generation systems  

Microsoft Academic Search

A unified model of a solar electric generation system (SEGS) is developed using a thermo–hydrodynamic model of a direct steam collector combined with a model of a traditional steam power house. The model is used to study the performance of different collector field and power house arrangements under Australian conditions. To find the effect of collector inclination on the SEGS

S. D Odeh; M Behnia; G. L Morrison

2003-01-01

412

Thermal and power generating performances of thermoelectric energy recovery modules  

Microsoft Academic Search

This paper seeks to demonstrate the performance of a thermoelectric energy recovery module (TERM). The TERM aims to convert the waste heat from power amplifier (PA) transistors into the useful power. The TERM contains a thermoelectric generator (TEG), a heat spreader, and a heat sink. A first order prototype of the TERM is generated and used as a test vehicle.

Kyoung Joon Kim

2010-01-01

413

THERMAL PERFORMANCE SIMULATION FROM AN ARCHITECTURAL DESIGN VIEWPOINT  

Microsoft Academic Search

The present paper is an attempt to bridge the gap between building designers and simulationists by proposing a common framework for discussion. It is a positional paper written from a building designer's viewpoint that basically agrees with the proposition that design is no longer dominated by physical structure thinking but by performance and system based concerns. However, the authors still

Clarice Bleil de Souza; Ian Knight

2007-01-01

414

Thermal performance of a new solar air heater  

Microsoft Academic Search

A solar air heater, part of a food drying system using solar energy as a renewable energy source for heat, was developed and tested for several agricultural products (i.e., sultana grapes, green beans, sweet peppers, chilli peppers). Drying processes were conducted in the chamber with forced natural air heated partly by solar energy. Solar air heater performances were discussed along

Mustafa Tiris; Ibrahim Dincer

1995-01-01

415

Thermal Performance of Cryogenic Multilayer Insulation at Various Layer Spacings.  

National Technical Information Service (NTIS)

Multilayer insulation (MLI) has been shown to be the best performing cryogenic insulation system at high vacuum (less that 10 (exp 3) torr), and is widely used on spaceflight vehicles. Over the past 50 years, many investigations into MLI have yielded a ge...

W. L. Johnson

2010-01-01

416

Planck early results. II. The thermal performance of Planck  

Microsoft Academic Search

The performance of the Planck instruments in space is enabled by their low operating temperatures, 20 K for LFI and 0.1 K for HFI, achieved through a combination of passive radiative cooling and three active mechanical coolers. The scientific requirement for very broad frequency coverage led to two detector technologies with widely different temperature and cooling needs. Active coolers could

P. A. R. Ade; N. Aghanim; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; M. Baker; A. Balbi; A. J. Banday; R. B. Barreiro; E. Battaner; K. Benabed; A. Benoît; J.-P. Bernard; M. Bersanelli; P. Bhandari; R. Bhatia; J. J. Bock; A. Bonaldi; J. R. Bond; J. Borders; J. Borrill; B. Bowman; T. Bradshaw; E. Bréelle; M. Bucher; C. Burigana; R. C. Butler; P. Cabella; C. M. Cantalupo; B. Cappellini; J.-F. Cardoso; A. Catalano; L. Cayón; A. Challinor; A. Chamballu; J. P. Chambelland; J. Charra; M. Charra; L.-Y. Chiang; C. Chiang; P. R. Christensen; D. L. Clements; B. Collaudin; S. Colombi; F. Couchot; A. Coulais; B. P. Crill; M. Crook; F. Cuttaia; C. Damasio; L. Danese; R. D. Davies; R. J. Davis; P. de Bernardis; G. de Gasperis; A. de Rosa; J. Delabrouille; J.-M. Delouis; F.-X. Désert; K. Dolag; S. Donzelli; O. Doré; U. Dörl; M. Douspis; X. Dupac; G. Efstathiou; T. A. Enßlin; H. K. Eriksen; C. Filliard; F. Finelli; S. Foley; O. Forni; P. Fosalba; J.-J. Fourmond; M. Frailis; E. Franceschi; S. Galeotta; K. Ganga; E. Gavila; M. Giard; G. Giardino; Y. Giraud-Héraud; J. González-Nuevo; K. M. Górski; S. Gratton; A. Gregorio; A. Gruppuso; G. Guyot; D. Harrison; G. Helou; S. Henrot-Versillé; C. Hernández-Monteagudo; D. Herranz; S. R. Hildebrandt; E. Hivon; M. Hobson; A. Hornstrup; W. Hovest; R. J. Hoyland; K. M. Huffenberger; U. Israelsson; A. H. Jaffe; W. C. Jones; M. Juvela; E. Keihänen; R. Keskitalo; T. S. Kisner; R. Kneissl; L. Knox; H. Kurki-Suonio; G. Lagache; J.-M. Lamarre; P. Lami; A. Lasenby; R. J. Laureijs; A. Lavabre; C. R. Lawrence; S. Leach; R. Lee; R. Leonardi; C. Leroy; P. B. Lilje; M. López-Caniego; P. M. Lubin; J. F. Macías-Pérez; T. Maciaszek; C. J. MacTavish; B. Maffei; D. Maino; N. Mandolesi; R. Mann; M. Maris; E. Martínez-González; S. Masi; S. Matarrese; F. Matthai; P. Mazzotta; P. McGehee; P. R. Meinhold; A. Melchiorri; F. Melot; L. Mendes; A. Mennella; M.-A. Miville-Deschênes; A. Moneti; L. Montier; J. Mora; G. Morgante; N. Morisset; D. Mortlock; D. Munshi; A. Murphy; P. Naselsky; A. Nash; P. Natoli; C. B. Netterfield; D. Novikov; I. Novikov; I. J. O'Dwyer; S. Osborne; F. Pajot; F. Pasian; G. Patanchon; D. Pearson; O. Perdereau; L. Perotto; F. Perrotta; F. Piacentini; M. Piat; S. Plaszczynski; P. Platania; E. Pointecouteau; G. Polenta; N. Ponthieu; T. Poutanen; G. Prézeau; M. Prina; S. Prunet; J.-L. Puget; J. P. Rachen; R. Rebolo; M. Reinecke; C. Renault; S. Ricciardi; T. Riller; I. Ristorcelli; G. Rocha; C. Rosset; J. A. Rubiño-Martín; B. Rusholme; M. Sandri; D. Santos; G. Savini; B. M. Schaefer; D. Scott; M. D. Seiffert; P. Shellard; G. F. Smoot; J.-L. Starck; P. Stassi; F. Stivoli; V. Stolyarov; R. Stompor; R. Sudiwala; J.-F. Sygnet; J. A. Tauber; L. Terenzi; L. Toffolatti; M. Tomasi; J.-P. Torre; M. Tristram; J. Tuovinen; L. Valenziano; L. Vibert; P. Vielva; F. Villa; N. Vittorio; A. Wilkinson; B. D. Wandelt; C. Watson; S. D. M. White; P. Wilson; D. Yvon; A. Zacchei; B. Zhang; A. Zonca

2011-01-01

417

IMPULSE-an advanced, high performance nuclear thermal propulsion system  

Microsoft Academic Search

IMPULSE is an advanced nuclear propulsion engine for future space missions based on a novel conical fuel. Fuel assemblies are formed by stacking a series of truncated (U, Zr)C cones with non-fueled lips. Hydrogen flows radially inward between the cones to a central plenum connected to a high performance bell nozzle. The reference IMPULSE engine rated at 75,000 lb thrust

Lyman J. Petrosky; R. Kep Disney; James D. Mangus; Stanley A. Gunn; Herbert R. Zweig

1993-01-01

418

IMPULSE—an advanced, high performance nuclear thermal propulsion system  

Microsoft Academic Search

IMPULSE is an advanced nuclear propulsion engine for future space missions based on a novel conical fuel. Fuel assemblies are formed by stacking a series of truncated (U, Zr)C cones with non-fueled lips. Hydrogen flows radially inward between the cones to a central plenum connected to a high performance bell nozzle. The reference IMPULSE engine rated at 75,000 lb thrust

Lyman J. Petrosky; R. Kep Disney; James D. Mangus; Stanley A. Gunn; Herbert R. Zweig

1993-01-01

419

Study on performance of a packed bed latent heat thermal energy storage unit integrated with solar water heating system  

Microsoft Academic Search

In thermal systems such as solar thermal and waste heat recovery systems, the available energy supply does not usually coincide in time with the process demand. Hence some form of thermal energy storage (TES) is necessary for the most effective utilization of the energy source. This study deals with the experimental evaluation of thermal performance of a packed bed latent

420

THE THERMAL ACCLIMATION OF BURST ESCAPE PERFORMANCE IN FISH: AN INTEGRATED STUDY OF MOLECULAR AND CELLULAR PHYSIOLOGY AND ORGANISMAL PERFORMANCE  

Microsoft Academic Search

Goldfish (Family Cyprinidae, Carassius auratus) and killifish (Family Cyprinodontidae, Fundulus heteroclitus) were acclimated to 10, 20 and 35 ?C for 4 weeks. The thermal acclimation of C-start (escape swimming) performance and the physiological properties of fast twitch muscle fibres that underlie it were investigated in these species at the molecular (myosin isoform expression), biochemical (myofibrillar ATPase activity), cellular (contractile kinetics)

TIMOTHY P. JOHNSON; ALBERT F. BENNETT

421

Thermal performance of a solar collector containing a boiling fluid (R-11)  

SciTech Connect

The experimental thermal performance of a flat-plate solar collector containing a boiling fluid is given for steady and unsteady thermosiphon operation. The steady-state thermal efficiency is shown to compare favorably with a new generalized formulation for collector efficiency. Collectors containing a boiling fluid have a thermal efficiency that is inherently greater than a nonboiling collector having the same value of the thermal parameter. Further, a boiling collector represents a class of solar collectors whose thermal efficiency approaches the theoretical maximum more closely than any other class of collector. The experimental data presented in this paper are taken on an R-11 charged boiling collector in natural sunlight. Experimental time response data are included.

Al-Tamimi, A.I.; Clark, J.A.

1984-01-01

422

Stenotherms at sub-zero temperatures: thermal dependence of swimming performance in Antarctic fish.  

PubMed

We examined the burst swimming performance of two Antarctic fishes, Trematomus bernacchii and T. centronotus, at five temperatures between -1 degrees C and 10 degrees C. As Antarctic fishes are considered one of the most cold specialised and stenothermal of all ectotherms, we predicted they would possess a narrow thermal performance breadth for burst swimming and a correlative decrease in performance at high temperatures. Burst swimming was assessed by videotaping swimming sequences with a 50-Hz video camera and analysing the sequences frame-by-frame to determine maximum velocity, the distance moved throughout the initial 200 ms, and the time taken to reach maximum velocity. In contrast to our prediction, we found both species possessed a wide thermal performance breadth for burst swimming. Although maximum swimming velocity for both T. bernacchii and T. centronotus was significantly highest at 6 degrees C, maximum velocity at all other test temperatures was less than 20% lower. Thus, it appears that specialisation to a highly stable and cold environment is not necessarily associated with a narrow thermal performance breadth for burst swimming in Antarctic fish. We also examined the ability of the Antarctic fish Pagothenia borchgrevinki to acclimate their burst-swimming performance to different temperatures. We exposed P. borchgrevinki to either -1 degrees C or 4 degrees C for 4 weeks and tested their burst-swimming performance at four temperatures between -1 degrees C and 10 degrees C. Burst-swimming performance of Pagothenia borchgrevinki was unaffected by exposure to either -1 degrees C or 4 degrees C for 4 weeks. Maximum swimming velocity of both acclimation groups was thermally independent over the total temperature range of 1 degrees C to 10 degrees C. Therefore, the loss of any capacity to restructure the phenotype and an inability to thermally acclimate swimming performance appears to be associated with inhabiting a highly stable thermal environment. PMID:11409623

Wilson, R S; Franklin, C E; Davison, W; Kraft, P

2001-05-01

423

Three-Dimensional Numerical Evaluation of Thermal Performance of Uninsulated Wall Assemblies: Preprint  

SciTech Connect

This study describes a detailed three-dimensional computational fluid dynamics modeling to evaluate the thermal performance of uninsulated wall assemblies accounting for conduction through framing, convection, and radiation. The model allows for material properties variations with temperature. Parameters that were varied in the study include ambient outdoor temperature and cavity surface emissivity. Understanding the thermal performance of uninsulated wall cavities is essential for accurate prediction of energy use in residential buildings. The results can serve as input for building energy simulation tools for modeling the temperature dependent energy performance of homes with uninsulated walls.

Ridouane, E. H.; Bianchi, M.

2011-11-01

424

Mechanical and thermal performance of C/SiC composites for SPICA mirror  

NASA Astrophysics Data System (ADS)

One of the key technologies for next generation space telescope with a large-scale reflector is a material having high specific strength, high specific stiffness, low coefficient of thermal expansion and high coefficient of thermal conductivity. Several candidates such as fused silica, beryllium, silicon carbide and carbon fiber reinforced composites have been evaluated. Pitch-based carbon fiber reinforced SiC composites were developed for the SPICA space telescope mirror to comply with such requirements. Mechanical performance such as bending stiffness, bending strength and fracture toughness was significantly improved. Evaluation procedures of thermal expansion and thermal conductivity behavior at cryogenic temperatures (as low as 4.5K) were established and excellent performance for the SPICA mirror was demonstrated.

Ozaki, T.; Kume, M.; Oshima, T.; Nakagawa, T.; Matsumoto, T.; Kaneda, H.; Murakami, H.; Kataza, K.; Enya, K.; Yui, Y.; Onaka, T.; Kroedel, M.

2005-08-01

425

Mechanical and thermal performance of C/SiC composites for SPICA mirror  

NASA Astrophysics Data System (ADS)

One of the key technologies for next generation space telescope with a large-scale reflector is a material having high specific strength, high specific stiffness, low coefficient of thermal expansion and high coefficient of thermal conductivity. Several candidates such as fused silica, beryllium, silicon carbide and carbon fiber reinforced composites have been evaluated. Pitch-based carbon fiber reinforced SiC composites were developed for the SPICA space telescope mirror to comply with such requirements. Mechanical performance such as bending stiffness, bending strength and fracture toughness was significantly improved. Evaluation procedures of thermal expansion and thermal conductivity behavior at cryogenic temperatures (as low as 4.5K) were established and excellent performance for the SPICA mirror was demonstrated.

Ozaki, Tsuyoshi; Kume, Masami; Oshima, Takeharu; Nakagawa, Takao; Matsumoto, Toshio; Kaneda, Hidehiro; Murakami, Hiroshi; Kataza, Koichi; Enya, Keigo; Yui, Yukari; Onaka, Takashi; Krodel, Matthias R.

2004-09-01

426

Prevention of residential roof fires by use of a class "A" fire rated roof system.  

PubMed

Because residential roof fires remain a life-threatening danger to residential homeowners in the United States, we describe in detail a national fire prevention program for reducing residential roof fires by use of an Underwriters Laboratories Inc. (UL) and National Fire Protection Association Class A fire rated roof system. This Class A system should comply with the test requirements for fire resistance of roof coverings, as outlined in UL 790 or in ASTM International (ASTM) E-108. Both the Asphalt Roofing Manufacturer's Association (ARMA) and the National Roofing Contractors Association (NRCA) have set up guidelines for selecting a new roof for the homeowner. Class A, fiber-glass-based asphalt roofing shingles represent an overwhelming share of the United States residential roofing market, and, as such, the Class A rated roofing system remains an excellent alternative to wood shingles and shakes. Fortunately, the Class A fire rating is available for certain wood shingle products that incorporate a factory-applied, fire resistant treatment. However, in this circumstance, wood products labeled as Class B shakes or shingles must be installed over spaced or solid sheathing that have been covered either with one layer of 1/4 in. (6.4 mm) thick noncombustible roof board, or with one layer of minimum 72-lb. fiber-glass-based mineral surfaced cap sheet, or with another specialty roofing sheet to obtain the Class A fire rating. Clay, tile, slate, and metal have been assigned Class A fire ratings in the codes (but often without testing). These alternative roofing materials are often considerably more expensive. Proper application, ventilation, and insulation of roofing systems are required to prevent heat and moisture buildup in the attic, which can damage the roofing system, making it more susceptible to water leakage as well as ignition in the event of a fire. The NRCA has devised excellent recommendations for the homeowner to prequalify the contractor. In addition, a warranty for any new roofing material is important for the homeowner to ensure that the roofing can be repaired by the contractor or manufacturer during the specified warranty period, in case of contractor error or a manufacturing defect. In addition, the homeowner should ensure that the warranty is transferable to any future owner of the home to allow the buyer to have the same warranty benefits as the original owner. The State of California has mandated strict roofing requirements to prevent residential fires. In the absence of this legislation in other states, the homeowner must follow the guidelines outlined in this collective review to ensure that a roofing system with Class A fire protection is installed. Other fire safety precautions that should also be considered mandatory are to include smoke alarms, escape plans, and retrofit fire sprinklers. PMID:15099189

Edlich, Richard F; Winters, Kathryne L; Long, William B; Britt, L D

2004-01-01

427

Prototype test article verification of the Space Station Freedom active thermal control system microgravity performance  

Microsoft Academic Search

To verify the on-orbit operation of the Space Station Freedom (SSF) two-phase external Active Thermal Control System (ATCS), a test and verification program will be performed prior to flight. The first system level test of the ATCS is the Prototype Test Article (PTA) test that will be performed in early 1994. All ATCS loops will be represented by prototypical components

I. Y. Chen; E. K. Ungar; D. Y. Lee; P. S. Beckstrom

1993-01-01

428

Prediction of thermal-hydraulic performance of gas-cooled fast breeder reactors. Final report  

Microsoft Academic Search

The report describes work performed under a project to examine the thermal-hydraulic performance of gas-cooled fast breeder reactors (GCFRs). Existing GCFR designs are briefly described with emphasis on the core cooling and associated systems. Factors affecting the convective heat transfer and pressure drop in the core are examined, particularly the effects of surface roughness on the enhancement of heat transfer,

C. Jr. Gazley; G. H. Harpole; L. S. Yao; W. H. Krase; J. Catton; J. Grzesik; W. Matyskiela

1977-01-01

429

Performance of abutment–backfill system under thermal variations in integral bridges built on clay  

Microsoft Academic Search

In this paper, performance of the abutment–backfill system under thermal variations is studied. For this purpose, a structural model of a typical integral bridge is built considering the nonlinear behavior of the piles and soil–bridge interaction effects. Static pushover analyses of the bridge are conducted to study the effect of various geometric, structural and geotechnical parameters on the performance of

Murat Dicleli; Suhail M. Albhaisi

2004-01-01

430

Thermal performance of a solar pressure cooker based on evacuated tube solar collector  

Microsoft Academic Search

This paper presents the thermal performance of a community type solar pressure cooker based on evacuated tube solar collector. The developed design of solar pressure cooker has separate parts for energy collection and cooking unit and both are coupled by heat exchanger. The paper has presented the performance results of experimental study conducted on solar pressure cooker and a simulation

Rakesh Kumar; R. S Adhikari; H. P Garg; Ashvini Kumar

2001-01-01

431

Experimental and Computational Evaluation of the Thermal Performance of Dou- ble Skin Façades  

Microsoft Academic Search

Double Skin Facades (DSF) have been a recently devel- oped technology to improve the thermal performance of conventional façades of buildings which use large glazed areas. However, there has been a lack of test in- formation on the behaviour and performance of a DSF. This is specifically the case when the façade has to per - form under extreme or

M. Hernández; L. Shao

2007-01-01

432

A high-performance clip on thermal sight for combat rifle scopes  

NASA Astrophysics Data System (ADS)

The Trijicon ATWS is a high performance, lightweight, compact clip on thermal sight for use with the TA31RCO ACOG® weapon sight. FLIR Systems partnered with Trijicon to develop this sight using the Photon 640 imaging core. This paper will discuss the features and performance of the ATWS and describe some of the design challenges associated with this type of device.

Way, Scott P.; Jolivet, Noel; Hansen, Joel; Schick, Darin; Maciak, Tom

2010-04-01

433

Improving MRI magnet thermal performance using variable density multilayer insulation  

NASA Astrophysics Data System (ADS)

Careful techniques for multilayer insulation (MLI) wrapping of MRI magnet cryostats have been shown to be critical in establishing a net Zero Helium Boil Off. Traditional MLI together with a cryocooler have been used in such 'Zero Boil Off' cryostats for many years. This paper discusses how the evolution in design of MRI magnet cryostats is challenging traditional MLI. By looking at the fundamental design equations for MLI, new insight can be gained into improving the design using variable density insulation. A new, proprietary method for creating variable density in MLI was devised and the resulting blankets were applied to MRI magnets. Results show a 10% improvement in insulation performance and a 42% improvement in material cost of the MLI. This new Variable Density MLI also holds promise for application to other liquid helium cryostats.

Zia, Jalal; Rutherford, William; Einziger, William

2012-06-01

434

Thermal performance and economic benefits of residential passive solar systems  

SciTech Connect

In earlier phases of the project a computer methodology was developed for electric utilities to use in analyzing the advantages and disadvantages, for themselves and their customers, of passive solar residential construction in their service areas. The specific objectives of Phase III were: to use the computer methodology to evaluate load management options not considered in Phases I and II of the project: ground-coupled heat pumps; a variety of passive solar building elements (infrared-reflecting window film, triple-pane windows, selective surfaces for mass walls, and highly reflective exterior surfaces); and multi-family passive solar units; and to compare building performance simulation results derived from the EMPS-2 computer program - the first of the four computer programs composing this methodology - with experimental data obtained in an existing full-scale passive solar demonstration project. Ground-coupled heat pumps were shown to be most cost-effective in northerly climates where heating loads dominate. They may also be economically viable in hot, cooling-load dominated climates if well drilling costs are reasonable. Analysis of infrared-reflecting window films, triple-pane windows, and selective surfaces for mass walls indicated that all are economically justifiable if considered on a life-cycle cost basis. Highly reflective exterior surfaces were found to be uneconomical. Evaluation of multifamily condominium units showed negligible differences in energy performance between the existing passive solar design and a simulated energy-conserving design using heavier insulation, smaller amounts of south-facing glass, electric resistance heat, and vapor air conditioning. EMPS-2 simulation results proved accurate and useful in all cases investigated.

Neal, R.W.; Wood, R.A.; McCabe, T.F.

1985-04-01

435

Field-structured, multilayered platelets enable high performance, dielectric thermal composites  

NASA Astrophysics Data System (ADS)

Moldable, thermally conductive polymer composites have broad applications as thermal interface materials and encapsulants. These thermal composites are generally comprised of single-phase particles that are randomly oriented and dispersed. Magnetic platelets have been shown to give exceptionally high thermal conductivities when magnetically aligned along the intended direction of heat flow, but produce composites that are electrically conductive. We have designed precision multilayered platelets that enable the development of high performance thermal composites that are electrically insulating. These platelets consist of a thin Ni core that permits field alignment, Al or Cu coatings that facilitate heat transport, and dielectric layers of MgF2 or SiO2 that ensure that the final composite is electrically insulating. These platelets can be made flat or corrugated, square or irregular, and the thickness of the various layers can be varied over a wide range. Thermal conductivity data for a variety of platelet compositions, layer thicknesses, and geometries demonstrate that these platelets are highly effective at producing composites with thermal conductivities much greater than that of the resin. Simulation data are presented that show that multilayer platelets have surprising dependencies of their efficiency for heat transfer on the relative thermal conductivities of the various layers. In fact, analysis shows that if the thermal conductivity of the particle phase is much greater than that of the resin, then the thermal conductivity of the composite, at fixed number density of particles, is insensitive to the platelet thickness. These electrically insulating composites would be especially useful as thermally conductive encapsulants for electronic devices.

Martin, James E.; Solis, Kyle J.; Rademacher, David; Raksha, Vladimir

2012-09-01

436

The technical viability of alternative blowing agents in polyisocyanurate roof insulation: A cooperative industry/government project  

SciTech Connect

This report is a summary of the cooperative industry/government program to establish the viability of alternative blowing agents to chlorofluorocarbons (CFCs). The project was initiated in 1989 following two workshops that focused on needed research on thermal insulation blown with substitutes for CFC-11 and CFC-12. The project is directed by a steering committee of representatives of the sponsors and of Oak Ridge National Laboratory (ORNL). The purpose of the project is to determine if the performance of polyisocyanurate (PIR) roof insulation foam boards blown with alternate agents differs from the performance of boards blown with CFC-1. This report describes apparent thermal conductivity (k) results obtained from field and laboratory tests from 1989 to 1992 on a set of experimental PIR laminate boardstock produced to evaluate the viability of alternative hydrochlorofluorocarbons (HCFCs) as blowing agents. All boardstock was manufactured from similar formulations that were not optimized for thermal performance. Commercial broadstock made in the future may differ in performance from this set. The PIR boards were prepared with CFC-11, HCFC-123, HCFC-141b, and 50/50 and 65/35 blends of HCFC-123/HCFC-141b.

Christian, J.E.; Courville, G.E.; Desjarlais, A.O.; Graves, R.S.; Linkous, R.L.; McElroy, D.L.; Weaver, F.J.; Wendt, R.L.; Yarbrough, D.W.

1993-06-01

437

The effect of roof strength on reducing occupant injury in rollovers.  

PubMed

Roof crush occurs and potentially contributes to serious or fatal occupant injury in 26% of rollovers. It is likely that glazing retention is related to the degree of roof crush experienced in rollover accidents. Occupant ejection (including partial ejection) is the leading cause of death and injury in rollover accidents. In fatal passenger car accidents involving ejection, 34% were ejected through the side windows. Side window glass retention during a rollover is likely to significantly reduce occupant ejections. The inverted drop test methodology is a test procedure to evaluate the structural integrity of roofs under loadings similar to those seen in real world rollovers. Recent testing on many different vehicle types indicates that damage consistent with field rollover accidents can be achieved through inverted drop testing at very small drop heights. Drop test comparisons were performed on 16 pairs of vehicles representing a large spectrum of vehicle types. Each vehicle pair includes a production vehicle and a vehicle with a reinforced roof structure dropped under the same test conditions. This paper offers several examples of post-production reinforcements to roof structures that significantly increase the crush resistance of the roof as measured by inverted drop tests. These modifications were implemented with minimal impact on vehicle styling, interior space and visual clearances. The results of these modifications indicate that roof crush can be mitigated by nearly an order of magnitude, as roof crush was reduced by 44-91% with only a 1-2.3% increase in vehicle weight. Additionally, this paper analyzes the glazing breakage patterns in the moveable tempered side windows on the side adjacent to the vehicle impact point in the inverted drop tests. A comparison is made between the production vehicles and the reinforced vehicles in order to determine if the amount roof crush is related to glazing integrity in the side windows. Lastly, two drop test pairs, performed with Hybrid III test dummies, indicates that the reduction of roof crush resulted in a direct reduction in neck loading and therefore an increase in occupant protection. PMID:15850089

Herbst, Brian; Forrest, Steve; Orton, Tia; Meyer, Steven E; Sances, Anthony; Kumaresan, Srirangam

2005-01-01

438

On-orbit thermal distortion and optical performance evaluation of FORMOSAT-5 remote sensing instrument  

NASA Astrophysics Data System (ADS)

FORMOSAT-5 is the first space program that National Space Organization (NSPO) takes full responsibility for the complete satellite system engineering design including payload(s). FORMOSAT-5 will operate in a sun synchronous orbit at 720-km altitude with 98.28-degree inclination angle. The optical Remote Sensing Instrument (RSI) can provide 2-m resolution panchromatic and 4-m resolution multi-spectral images. A Cassegrain type of RSI with two reflective aspheric mirrors and spherical corrector lens is designed. The space thermal environment is one of the important factors that affect the image quality of a space optical RSI. Thermal deformation of RSI structure and mirrors will impact the optical performance. Some preliminary thermal and opto-mechanical analyses are conducted. The relationship among temperature distributions, thermal deformations and image degradation of on-orbit behaviors are discussed. The thermal induced instabilities are incorporated in optical models (e.g., OSLO) by use of Zernike polynomial coefficients to calculate the system MTF and WFE. Due to different thermal environments, on-orbit optical performances depend on imaging locations. Detailed studies and discussions are done in this paper to identify the major sources of thermal deformations and their impacts on image quality.

Ching-Wei, Chen; Chia-Ray, Chen; Ho, Cheng-En; Yang, Mei-Yi; Chang, Shenq-Tsong; Huang, T.-M.

2012-10-01

439

The selection and performance of thermal sprayed abradable seal coatings for gas turbine engines  

SciTech Connect

Criteria used in designing thermal sprayed abradable seal coatings for gas turbine engines are discussed. These include the conditions of being readily abradable and yet being resistable to particle impact erosion from engine-ingested abrasive dust at high gas velocities. Other important criteria include temperature stability, inertness, and consistency. The paper describes the classes of abradable seal materials; the characterization of thermal sprayed abradables; the current coating materials' temperature, erosion, and abradability performance; and current research in thermal sprayed abradable coating materials. 5 refs.

Novinski, E.R.

1989-01-01

440

Thermal performance measurements of a graphite tube compact cryogenic support for the Superconducting Super Collider  

SciTech Connect

The magnet cryostat development program for the Superconducting Super Collider (SSC) High Energy Physics Proton-Proton Collider has produced an innovative design for the structural support of the cold mass and thermal radiation shields. This work updates the continuing development of the support known as the Compact Cryogenic Support (CCS). As the structural and thermal requirements of the SSC became better defined, a CCS was developed that employs an innermost tube comprised of a graphite composite material. Presented is the thermal performance to 4.5K of the graphite CCS model. 8 refs., 6 figs., 2 tabs.

Gonczy, J.D.; Boroski, W.N.; Larson, E.T.; Nicol, T.H.; Niemann, R.C.; Otavka, J.G.; Ruschman, M.K.

1988-12-01

441

Modeling of target thermal structure effects on the performance of staring IR seekers  

NASA Astrophysics Data System (ADS)

The target thermal structure is playing a stronger role in modeling the performance of autonomous IR seekers to acquire and track targets. The impact of the target thermal structure on seeker and sensor acquisition has been previously reported. In this paper, the impact of the target's thermal structure on the acquisition and tracking capability of autonomous imaging IR seekers using staring focal plane arrays is assessed. This paper examines both the magnitude of the thermal structure, referred to as the vehicle's thermal standard deviation, and the distribution of the thermal structure, referred to as the power spectral density (PSD). The vehicle's thermal PSD is important in that it determines how much structure the seeker will see given the number of resolvable pixels the seeker has on the target. PSDs that reflect actual armored targets as well as simple warm bodies with a single hot spot are explored. PSDs that are necessary for targets to optimally match the background clutter are also addressed. In addition to the impact of the target's thermal structure, the impact of aliasing effects that can be present in staring seekers is discussed. Relative advantages of trading off resolution versus eliminating aliasing effects are presented.

Borg, Eric J.

1994-07-01

442

Thermal performance of an Ekose'a-design double-envelope house  

Microsoft Academic Search

To assess the energy effectiveness of a double-envelope house, an Ekose'a-design house has been monitored. Thermal characteristics of the house and the amount of auxiliary backup heat required in the heating season are assessed. House thermal behavior during representative days in the swing or cooling season is determined, and integrated or averaged monthly results homogeneous patterns of daily performance and

H. T. Ghaffari; R. F. Jones

1981-01-01

443

Performance analysis of photovoltaic-thermal collector by explicit dynamic model  

Microsoft Academic Search

Although the performance of hybrid photovoltaic-thermal (PV\\/T) collector had been studied both experimentally and numerically for some years, the thermal models developed in previous studies were mostly steady-state models for predicting the annual yields. The operation of a PV\\/T collector is inherently dynamic. A steady-state model is not suitable for predicting working temperatures of the PV module and the heat-removal

T. T. Chow

2003-01-01

444

Predicting the performance of amorphous and crystalline silicon based photovoltaic solar thermal collectors  

Microsoft Academic Search

BIPVT is an application where solar PV\\/T modules are integrated into the building structure. System design parameters such as thermal conductivity and fin efficiency, type of cells, type of coolant and operating conditions are factors which influence the performance of BIPVT. Attempts have been made to improve the efficiency of building-integrated photovoltaic thermal (BIPVT). A new design concept of water-based

Ronak Daghigh; Adnan Ibrahim; Goh Li Jin; Mohd Hafidz Ruslan; Kamaruzzaman Sopian

2011-01-01

445

Thermal conductivity of UO 2 fuel: Predicting fuel performance from simulation  

Microsoft Academic Search

Recent progress in understanding the thermal-transport properties of UO2 for fission reactors is reviewed from the perspective of computer simulations. A path to incorporating more accurate materials\\u000a models into fuel performance codes is outlined. In particular, it is argued that a judiciously integrated program of atomic-level\\u000a simulations and mesoscale simulations offers the possibility of both better predicting the thermal-transport properties

Simon R. Phillpot; Anter El-Azab; Aleksandr Chernatynskiy; James S. Tulenko

2011-01-01

446

Thermal conductivity of UO2 fuel: Predicting fuel performance from simulation  

Microsoft Academic Search

Recent progress in understanding the thermal-transport properties of UO2 for fission reactors is reviewed from the perspective of computer simulations. A path to incorporating more accurate materials models into fuel performance codes is outlined. In particular, it is argued that a judiciously integrated program of atomic-level simulations and mesoscale simulations offers the possibility of both better predicting the thermal-transport properties

Simon R. Phillpot; Anter El-Azab; Aleksandr Chernatynskiy; James S. Tulenko

2011-01-01

447

Thermal hydraulic performance analysis of a double tube bundle steam generator for a liquid metal reactor  

Microsoft Academic Search

In this study, thermal-hydraulic performance of a double tube bundle steam generator (DTBSG) using helically coiled tubes was analyzed numerically. For this purpose a one-dimensional thermal-hydraulic analysis computer program was developed.The DTBSG contains hot fluid and cold fluid tube bundles, a medium fluid and a pump for a medium fluid circulation in an SG. Heat is transferred from the hot

Eui-Kwang Kim; Byung-Joon Baek

2011-01-01

448

Thermal Performance of Sprayed Polyurethane Foam Insulation with Alternative Blowing Agents  

Microsoft Academic Search

A test methodology that uses thermal resistance-time curves deter mined on thin shces of the foam and the scaling technique to relate aging time to the specimen thickness, was applied to evaluate long-term thermal performance of six polyurethane foams manufactured with the same polymer but different blowing agents. The blowing agents employed were: CFC-11 with 0, 0 5, 1 0

M. K. Kumaran; M. T. Bomberg

1990-01-01

449

Thermal performance of a commercial alkaline water electrolyzer: Experimental study and mathematical modeling  

Microsoft Academic Search

In this paper a study of the thermal performance of a commercial alkaline water electrolyzer (HySTAT from Hydrogenics) designed for a rated hydrogen production of 1Nm3 H2\\/h at an overall power consumption of 4.90kWh\\/Nm3 H2 is presented. The thermal behaviour of the electrolyzer has been analyzed under different operating conditions with an IR camera and several thermocouples placed on the

P. M. Diéguez; A. Ursúa; P. Sanchis; C. Sopena; E. Guelbenzu; L. M. Gandía

2008-01-01

450

Calorimetric thermal-vacuum performance characterization of the BAe 80 K space cryocooler  

Microsoft Academic Search

A comprehensive characterization program is underway at JPL to generate test data on long-life, miniature Stirling-cycle cryocoolers for space application. The key focus of this paper is on the thermal performance of the British Aerospace (BAe) 80 K split-Stirling-cycle cryocooler as measured in a unique calorimetric thermal-vacuum test chamber that accurately simulates the heat-transfer interfaces of space. Two separate cooling

V. Y. Kotsubo; D. L. Johnson; R. G. Ross Jr.

1992-01-01

451

Study on the cell size effect of steady state thermal performance of metallic honeycomb sandwich panels  

NASA Astrophysics Data System (ADS)

In this paper, numerical study is performed to reveal the influences of the cell size on the steady state thermal performance of hexagonal metallic honeycomb sandwich panel, by using the semi-empirical Swann and Pittman formula and the Finite Element Method (FEM), respectively. Based on the same material volume of honeycomb core, two types of hexagonal honeycomb core, i.e., size variation of core cell with a constant core height and height variation of core with a constant side length of hexagonal cell, are considered to establish the panel's thermal analysis model, which including the conduction and radiation coupling. Comparisons between the temperature distribution results from both methods show that FEM can reveal the size effect of the honeycomb cell on the thermal performances of sandwich panel while the Swann and Pittman formula can not. At the same time, numerical results show that for the core with constant height, the panel thermal performance analyzed by FEM has a tendency of being close to the results obtained from Swann and Pittman formula as the core cell size decreases; whereas, if the hexagonal cell with constant side length is concerned, the greater the core height, the worse the thermal conductive performance of sandwich panel. Besides, analyses based on both methods also show that the temperature distribution of the lower surface of panel becomes gradually uniform when the wall thickness of hexagonal cell decreases.

Lai, Yu-dong; Sun, Shi-ping

2011-11-01

452

Application of spatial frequency response as a criterion for evaluating thermal imaging camera performance  

NASA Astrophysics Data System (ADS)

Police, firefighters, and emergency medical personnel are examples of first responders that are utilizing thermal imaging cameras in a very practical way every day. However, few performance metrics have been developed to assist first responders in evaluating the performance of thermal imaging technology. This paper describes one possible metric for evaluating spatial resolution using an application of Spatial Frequency Response (SFR) calculations for thermal imaging. According to ISO 12233, the SFR is defined as the integrated area below the Modulation Transfer Function (MTF) curve derived from the discrete Fourier transform of a camera image representing a knife-edge target. This concept is modified slightly for use as a quantitative analysis of the camera's performance by integrating the area between the MTF curve and the camera's characteristic nonuniformity, or noise floor, determined at room temperature. The resulting value, which is termed the Effective SFR, can then be compared with a spatial resolution value obtained from human perception testing of task specific situations to determine the acceptability of the performance of thermal imaging cameras. The testing procedures described herein are being developed as part of a suite of tests for possible inclusion into a performance standard on thermal imaging cameras for first responders.

Lock, Andrew; Amon, Francine

2008-05-01

453

KENIS: a high-performance thermal imager developed using the OSPREY IR detector  

NASA Astrophysics Data System (ADS)

`KENIS', a complete, high performance, compact and lightweight thermal imager, is built around the `OSPREY' infrared detector from BAE systems Infrared Ltd. The `OSPREY' detector uses a 384 X 288 element CMT array with a 20 micrometers pixel size and cooled to 120 K. The relatively small pixel size results in very compact cryogenics and optics, and the relatively high operating temperature provides fast start-up time, low power consumption and long operating life. Requiring single input supply voltage and consuming less than 30 watts of power, the thermal imager generates both analogue and digital format outputs. The `KENIS' lens assembly features a near diffraction limited dual field-of-view optical system that has been designed to be athermalized and switches between fields in less than one second. The `OSPREY' detector produces near background limited performance with few defects and has special, pixel level circuitry to eliminate crosstalk and blooming effects. This, together with signal processing based on an effective two-point fixed pattern noise correction algorithm, results in high quality imagery and a thermal imager that is suitable for most traditional thermal imaging applications. This paper describes the rationale used in the development of the `KENIS' thermal imager, and highlights the potential performance benefits to the user's system, primarily gained by selecting the `OSPREY' infra-red detector within the core of the thermal imager.

Goss, Tristan M.; Baker, Ian M.

2000-07-01

454

Solar panel installation configurations for optimum system performance  

NASA Astrophysics Data System (ADS)

The main object of this paper is to identify solar panel installation configurations to achieve optimum system performance irrespective of installation surface configurations. It is important to mention that the panel installation requirements are strictly dependent on the roof configurations, Northern and Southern hemispherical locations, and the latitudes of the installation locations. Panel installation schemes for flat roof, inclined roof, inverted V-shape roof and other roof configurations are briefly discussed. Potential tracking concepts, tracking algorithms, and controllers are identified.

Jha, A. R.

2010-08-01

455

Thermal performance of gaseous-helium-purged tank-mounted multilayer insulation system during ground-hold and space-hold thermal cycling and exposure to water vapor  

Microsoft Academic Search

An experimental investigation was conducted to determine (1) the ground-hold and space-hold thermal performance of a multilayer insulation (MLI) system mounted on a spherical, liquid-hydrogen propellant tank and (2) the degradation to the space-hold thermal performance of the insulation system that resulted from both thermal cycling and exposure to moisture. The propellant tank had a diameter of 1.39 meters (4.57ft).

I. E. Sumner

1978-01-01

456

Planck early results. II. The thermal performance of Planck  

NASA Astrophysics Data System (ADS)

The performance of the Planck instruments in space is enabled by their low operating temperatures, 20 K for LFI and 0.1 K for HFI, achieved through a combination of passive radiative cooling and three active mechanical coolers. The scientific requirement for very broad frequency coverage led to two detector technologies with widely different temperature and cooling needs. Active coolers could satisfy these needs; a helium cryostat, as used by previous cryogenic space missions (IRAS, COBE, ISO, Spitzer, AKARI), could not. Radiative cooling is provided by three V-groove radiators and a large telescope baffle. The active coolers are a hydrogen sorption cooler (<20 K), a 4He Joule-Thomson cooler (4.7 K), and a 3He-4He dilution cooler (1.4 K and 0.1 K). The flight system was at ambient temperature at launch and cooled in space to operating conditions. The HFI bolometer plate reached 93 mK on 3 July 2009, 50 days after launch. The solar panel always faces the Sun, shadowing the rest of Planck, andoperates at a mean temperature of 384 K. At the other end of the spacecraft, the telescope baffle operates at 42.3 K and the telescope primary mirror operates at 35.9 K. The temperatures of key parts of the instruments are stabilized by both active and passive methods. Temperature fluctuations are driven by changes in the distance from the Sun, sorption cooler cycling and fluctuations in gas-liquid flow, and fluctuations in cosmic ray flux on the dilution and bolometer plates. These fluctuations do not compromise the science data.

Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Baker, M.; Balbi, A.; Banday, A. J.; Barreiro, R. B.; Battaner, E.; Benabed, K.; Benoît, A.; Bernard, J.-P.; Bersanelli, M.; Bhandari, P.; Bhatia, R.; Bock, J. J.; Bonaldi, A.; Bond, J. R.; Borders, J.; Borrill, J.; Bouchet, F. R.; Bowman, B.; Bradshaw, T.; Bréelle, E.; Bucher, M.; Burigana, C.; Butler, R. C.; Cabella, P.; Camus, P.; Cantalupo, C. M.; Cappellini, B.; Cardoso, J.-F.; Catalano, A.; Cayón, L.; Challinor, A.; Chamballu, A.; Chambelland, J. P.; Charra, J.; Charra, M.; Chiang, L.-Y.; Chiang, C.; Christensen, P. R.; Clements, D. L.; Collaudin, B.; Colombi, S.; Couchot, F.; Coulais, A.; Crill, B. P.; Crook, M.; Cuttaia, F.; Damasio, C.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Gasperis, G.; de Rosa, A.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dolag, K.; Donzelli, S.; Doré, O.; Dörl, U.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.; Filliard, C.; Finelli, F.; Foley, S.; Forni, O.; Fosalba, P.; Fourmond, J.-J.; Frailis, M.; Franceschi, E.; Galeotta, S.; Ganga, K.; Gavila, E.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Guyot, G.; Harrison, D.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Hoyland, R. J.; Huffenberger, K. M.; Israelsson, U.; Jaffe, A. H.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knox, L.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lami, P.; Lasenby, A.; Laureijs, R. J.; Lavabre, A.; Lawrence, C. R.; Leach, S.; Lee, R.; Leonardi, R.; Leroy, C.; Lilje, P. B.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maciaszek, T.; MacTavish, C. J.; Maffei, B.; Maino, D.; Mandolesi, N.; Mann, R.; Maris, M.; Martínez-González, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Melot, F.; Mendes, L.; Mennella, A.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Mora, J.; Morgante, G.; Morisset, N.; Mortlock, D.; Munshi, D.; Murphy, A.; Naselsky, P.; Nash, A.; Natoli, P.; Netterfield, C. B.; Novikov, D.; Novikov, I.; O'Dwyer, I. J.; Osborne, S.; Pajot, F.; Pasian, F.; Patanchon, G.; Pearson, D.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Plaszczynski, S.; Platania, P.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Poutanen, T.; Prézeau, G.; Prina, M.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Rebolo, R.; Reinecke, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Schaefer, B. M.; Scott, D.; Seiffert, M. D.; Shellard, P.; Smoot, G. F.; Starck, J.-L.; Stassi, P.; Stivoli, F.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Torre, J.-P.; Tristram, M.; Tuovinen, J.; Valenziano, L.; Vibert, L.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Watson, C.; White, S. D. M.; Wilkinson, A.; Wilson, P.; Yvon, D.; Zacchei, A.; Zhang, B.; Zonca, A.

2011-12-01

457

Effects of Infrared-Reflective and Antireflective Glazing on Thermal Comfort and Visual Performance: A Literature Review.  

National Technical Information Service (NTIS)

The existing literature on the effects of infrared-reflective (IRR) and antireflective (AR) automotive glazing on thermal comfort and visual performance was reviewed. First, 78 articles on the broader topic of thermal comfort in motor vehicles were analyz...

J. M. Devonshire J. R. Sayer

2002-01-01

458

Multilayer Insulation (MLI) In the Superconducting Super Collider: A Practical Engineering Approach to Physical Parameters Governing MLI Thermal Performance.  

National Technical Information Service (NTIS)

Multilayer insulation (MLI) is employed in cryogenic devices to control the heat load of those devices. The physics defining the thermal performance of an MLI system is extremely complex due to the thermal dynamics of numerous interdependent parameters wh...

J. D. Gonczy W. N. Boroski R. C. Niemann

1989-01-01

459

Roof apertures in office buildings  

Microsoft Academic Search

An investigation has been made of potential lighting electricity reductions and associated thermal impacts of replacing electric light with sunlight admitted through rooftop glazing on a single-story, prototypical office building. Experimental scale models have been used to determine the fraction of the solar radiation entering the aperture which reaches the work plane as useful illumination. This information is used in

M. Fontoynont; C. Conner; R. C. Kammerud; B. Anderson; F. Bauman; W. Carroll; T. C. Howard; A. Mertol; T. Webster

1983-01-01

460

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

PubMed

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. PMID:21713491

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

2011-06-29

461

Thermal and hydraulic performance of a sieve-tray direct-contact heat exchanger  

SciTech Connect

Experiments investigating the thermal and hydraulic performance of a sieve tray direct contact heat exchanger (DCHX) were conducted using a 275/sup 0/ geothermal fluid as an energy source and different hydrocarbons as working fluids. The baseline performance tests with the direct contact unit were conducted with isobutane. The thermal performance of the unit met or exceeded the design goals for individual tray thermal efficiencies and pinch points. Hydraulically the column operated near recommended design fluid velocities. Following the completion of these tests, the DCHX was operated with different mixtures of hydrocarbon working fluids. Different combinations of the isobutane/hexane family were tested followed by a series with propane/isopentane fluids. The testing conducted with the direct contact unit showed that the sieve tray column is a very efficient heat exchange device although some degradation in boiling tray efficiency and column throughput were noted when mixtures were used.

Mines, G.L.; Wiggins, D.J.

1983-01-01

462

5cm, no iron SSC dipole 12m model cryostat thermal performance  

SciTech Connect

A 12 m long model of a 5 cm costheta dipole cryostat has been constructed and its thermal performance measured. The model utilized heat intercepted fiberglass reinforced plastic posts to support the 12 m long, 4.5 K cold mass and the 10 and 80 K thermal shields. A superinsulation blanket system utilizing aluminized polyester with fiberglass mat spacing material was developed and installed on the 10 and 80 K thermal shields. The heat gain to 4.5, 10 and 80 K was measured. We have compared the results with the analytical predicted performance and it shows good agreement. The performance of the multilayer insulation system has been measured under several different system conditions and the results are reported. 6 refs., 5 figs.

Powers, R.J.; Gonczy, J.D.; Otavka, J.; Niemann, R.C.; Szymulanski, A.; Tague, J.L.

1985-09-01

463

Performance study of solar cell arrays based on a Trough Concentrating Photovoltaic\\/Thermal system  

Microsoft Academic Search

The performances of solar cell arrays based on a Trough Concentrating Photovoltaic\\/Thermal (TCPV\\/T) system have been studied via both experiment and theoretical calculation. The I–V characteristics of the solar cell arrays and the output performances of the TCPV\\/T system demonstrated that among the investigated four types of solar cell arrays, the triple junction GaAs cells possessed good performance characteristics and

Ming Li; Xu Ji; Guoliang Li; Shengxian Wei; YingFeng Li; Feng Shi

2011-01-01

464

46. C. 1854 BUILDING ATTIC ROOF SPACE, VIEW OF KING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

46. C. 1854 BUILDING ATTIC ROOF SPACE, VIEW OF KING POST TRUSS ALONG LENGTH OF THE BUILDING. RAILS ON FLOOR FOR MOVEMENT OF GOODS STORED IN ROOF SPACE. - Continental Gin Company, Prattville, Autauga County, AL

465

30 CFR 75.213 - Roof support removal.  

Code of Federal Regulations, 2013 CFR

...as provided in paragraph (g) of this section, permanent support shall not be removed whereâ (1) Roof bolt torque or tension measurements or the condition of conventional support indicate excessive loading; (2) Roof fractures are present;...

2013-07-01

466

BLACKSMITH SHOP ROOF STRUCTURE AT JUNCTION BETWEEN 60 FT. AND ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

BLACKSMITH SHOP ROOF STRUCTURE AT JUNCTION BETWEEN 60 FT. AND 90 FT. SPAN ROOF TRUSSES, LOOKING SOUTH. - Southern Pacific, Sacramento Shops, Blacksmith Shop, 111 I Street, Sacramento, Sacramento County, CA

467

30 CFR 75.221 - Roof control plan information.  

Code of Federal Regulations, 2013 CFR

... Roof control plan information. 75.221 Section... MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT...COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL... Roof control plan information. (a) The...

2013-07-01

468

Health Hazard Evaluation/Toxicity Determination Report 75-194-324, Western Roofing Company, Sellers and Marquis Roofing Company, A. J. Shirk Roofing Company, Quality Roofing Company, Kansas City, Missouri.  

National Technical Information Service (NTIS)

The results of a medical-environmental evaluation indicates that employees were exposed to toxic concentrations of particulate polycyclic organic matter during roofing operations involving the tear-off of a 7 acre roof. The particulate polycyclic organic ...

R. L. Hervin E. A. Emmett

1976-01-01

469

Thermoplastic Single-Ply Roof Relieves Water Damage and Inconvenience.  

ERIC Educational Resources Information Center

|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)|

Williams, Jennifer Lynn

2002-01-01

470

5. ROOF DETAIL, LOOKING EAST TOWARD SECOND FLOOR WAREHOUSE FROM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. ROOF DETAIL, LOOKING EAST TOWARD SECOND FLOOR WAREHOUSE FROM ROOF OF ASSEMBLY AREA. - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

471

13. INTERIOR OF TAN 629 HANGAR, TAKEN ON LOW ROOF ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. INTERIOR OF TAN 629 HANGAR, TAKEN ON LOW ROOF ON WEST SIDE, FACING SOUTH. SHOWS SMC ROOF UTILITY PAD. - Idaho National Engineering Laboratory, Test Area North, Hangar No. 629, Scoville, Butte County, ID

472

Detail view of roof construction where cornice has fallen away, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Detail view of roof construction where cornice has fallen away, exposing column, beam, and concrete plank roof juncture, looking north - Trenton Jewish Community Center, Day Camp Pavilions, 999 Lower Ferry Road, Ewing, Mercer County, NJ

473

Effect of Amount of Fluid Charge in Thermal Performance of Loop Heat Pipe  

NASA Astrophysics Data System (ADS)

Loop Heat Pipes (LHPs) are two-phase thermal control system, which works only by heat from its cooling target. In order to utilize the LHPs in various fields, it is requested to be smaller, more reliable, and higher performance. In the present study, a miniature LHP has been fabricated, and the effect of amount of working fluid charged on thermal performance of the LHPs has been investigated. Tests were conducted including start-up, power step up, as function of amount of working fluid. The test results showed that under-charging of working fluid caused start-up failure, while over-charging of working fluid made the LHP less stable.

Onogawa, Ei; Nagano, Housei; Fukuyoshi, Fuyuko; Ogawa, Hiroyuki; Nagai, Hiroki

474

Attic or Roof? An Evaluation of Two Advanced Weatherization Packages  

SciTech Connect

This project examines implementation of advanced retrofit measures in the context of a large-scale weatherization program and the archetypal Chicago brick bungalow. One strategy applies best practice air sealing methods and a standard insulation method to the attic floor. The other strategy creates an unvented roof assembly using materials and methods typically available to weatherization contractors. Through implementations of the retrofit strategies in a total of eight (8) test homes, the research found that the two different strategies achieve similar reductions in air leakage measurement (55%) and predicted energy performance (18%) relative to the pre-retrofit conditions.

Neuhauser, K.

2012-06-01

475

A novel performance monitoring strategy for economical thermal power plant operation  

SciTech Connect

A need-based integrated performance monitoring strategy is proposed to economize the operation of a thermal power plant, exploiting the immensely powerful resources of newly retrofitted modern Distributed Control System (DCS). After reviewing the performance monitoring practice of a typical 200 MW oil/gas fired thermal power plant at Ballylumford, N. Ireland, the paper analyses its shortcomings and then suggests remedial measures through the proposed strategy. A simulation of this plant has been used for investigation purposes. The twin key aspects of performance monitoring, i.e. monitoring of performance indices and controllable parameters, are addressed in more effective and novel ways. The achievable best efficiency values of plant components, needed for comparative performance evaluation, are shown to be more reliably and accurately obtainable through neural network performance models. A method based on histogram plots is shown to be highly effective in monitoring the performance of plant controllers in reducing the variability of plant variables and then modifying the set-points to improve the thermal performance of the plant.

Prasad, G.; Swidenbank, E.; Hogg, B.W.

1999-09-01

476

An experiment to evaluate the thermal performance of an oil-heating copper spiral coil  

NASA Astrophysics Data System (ADS)

An experimental setup to evaluate the thermal performance of an oil-heating copper spiral coil heat exchanger is presented. The thermal performance is evaluated in terms of energy and exergy analyses. Results obtained while increasing the flow-rate of the fluid through the coil show an increased heat transfer rate, resulting in a reduction in the temperature difference between the outlet and inlet temperatures of the coil. An increase in the flow-rate is found to increase the rate of heat gained by the oil for a limited range of the flow-rate since heat losses are also increased. The average rate of heat gained by the oil is found to be around 350 W, while the average thermal efficiency of the coil is found to be around 0.25. The rate of exergy delivery and exergy factor results show that lower flow-rates result in a greater rate for the exergy delivered to the oil during the initial stages of the experiments. The heat loss factor is found to increase with an increase in the flow-rate. Due to the simplicity of the experimental setup, it can be used to introduce experimentally the concepts of energetic and exergetic performance of a thermal process or device to senior undergraduate students taking courses in applied thermal physics or applied thermodynamics.

Mawire, A.; Abedigamba, O. P.

2013-05-01

477

Roof Blisters, Physical Fitness Building, Fort Lee, Virginia.  

National Technical Information Service (NTIS)

The blisters on this 2-year old roof were first noticed one year after construction. Findings show that all blisters were built into the roof and that they will continue to develop in size and number. Currently, this roof is watertight, but leaks will occ...

C. Korhonen J. Bayer

1986-01-01

478

Recovery and reuse of asphalt roofing waste. Final report  

SciTech Connect

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