WorldWideScience

Sample records for fibrous thermal insulation

  1. Treating Fibrous Insulation to Reduce Thermal Conductivity

    Science.gov (United States)

    Zinn, Alfred; Tarkanian, Ryan

    2009-01-01

    A chemical treatment reduces the convective and radiative contributions to the effective thermal conductivity of porous fibrous thermal-insulation tile. The net effect of the treatment is to coat the surfaces of fibers with a mixture of transition-metal oxides (TMOs) without filling the pores. The TMO coats reduce the cross-sectional areas available for convection while absorbing and scattering thermal radiation in the pores, thereby rendering the tile largely opaque to thermal radiation. The treatment involves a sol-gel process: A solution containing a mixture of transition-metal-oxide-precursor salts plus a gelling agent (e.g., tetraethylorthosilicate) is partially cured, then, before it visibly gels, is used to impregnate the tile. The solution in the tile is gelled, then dried, and then the tile is fired to convert the precursor salts to the desired mixed TMO phases. The amounts of the various TMOs ultimately incorporated into the tile can be tailored via the concentrations of salts in the solution, and the impregnation depth can be tailored via the viscosity of the solution and/or the volume of the solution relative to that of the tile. The amounts of the TMOs determine the absorption and scattering spectra.

  2. Multilayer Impregnated Fibrous Thermal Insulation Tiles

    Science.gov (United States)

    Tran, Huy K.; Rasky, Daniel J.; Szalai, Christine e.; Hsu, Ming-ta; Carroll, Joseph A.

    2007-01-01

    The term "secondary polymer layered impregnated tile" ("SPLIT") denotes a type of ablative composite-material thermal- insulation tiles having engineered, spatially non-uniform compositions. The term "secondary" refers to the fact that each tile contains at least two polymer layers wherein endothermic reactions absorb considerable amounts of heat, thereby helping to prevent overheating of an underlying structure. These tiles were invented to afford lighter-weight alternatives to the reusable thermal-insulation materials heretofore variously used or considered for use in protecting the space shuttles and other spacecraft from intense atmospheric-entry heating.

  3. Determination of physical properties of fibrous thermal insulation

    Directory of Open Access Journals (Sweden)

    Jeandel G.

    2012-10-01

    Full Text Available The objective of this study is to characterize both experimentally and theoretically, conductive and radiative heat transfer within polyester batting. This material is derived from recycled bottles (PET with fibres of constant diameters. Two other mineral and plant fibrous insulation materials, (glass wool and hemp wool are also characterized for comparative purposes. To determine the overall thermophysical properties of the tested materials, heat flux measurement are carried out using a device developed in house. The radiative properties of the material are determined by an inverse method based on measurements of transmittance and reflectance using a FTIR spectrometer and by solving the equation of radiative heat transfer. These measures are compared to results of numerical simulations.

  4. Simultaneous reconstruction of thermal degradation properties for anisotropic scattering fibrous insulation after high temperature thermal exposures

    International Nuclear Information System (INIS)

    Zhao, Shuyuan; Zhang, Wenjiao; He, Xiaodong; Li, Jianjun; Yao, Yongtao; Lin, Xiu

    2015-01-01

    To probe thermal degradation behavior of fibrous insulation for long-term service, an inverse analysis model was developed to simultaneously reconstruct thermal degradation properties of fibers after thermal exposures from the experimental thermal response data, by using the measured infrared spectral transmittance and X-ray phase analysis data as direct inputs. To take into account the possible influence of fibers degradation after thermal exposure on the conduction heat transfer, we introduced a new parameter in the thermal conductivity model. The effect of microstructures on the thermal degradation parameters was evaluated. It was found that after high temperature thermal exposure the decay rate of the radiation intensity passing through the material was weakened, and the probability of being scattered decreased during the photons traveling in the medium. The fibrous medium scattered more radiation into the forward directions. The shortened heat transfer path due to possible mechanical degradation, along with the enhancement of mean free path of phonon scattering as devitrification after severe heat treatment, made the coupled solid/gas thermal conductivities increase with the rise of heat treatment temperature. - Highlights: • A new model is developed to probe conductive and radiative properties degradation of fibers. • To characterize mechanical degradation, a new parameter is introduced in the model. • Thermal degradation properties are reconstructed from experiments by L–M algorithm. • The effect of microstructures on the thermal degradation parameters is evaluated. • The analysis provides a powerful tool to quantify thermal degradation of fiber medium

  5. Flight Performance of an Advanced Thermal Protection Material: Toughened Uni-Piece Fibrous Insulation

    Science.gov (United States)

    Leiser, Daniel B.; Gordon, Michael P.; Rasky, Daniel J. (Technical Monitor)

    1995-01-01

    The flight performance of a new class of low density, high temperature thermal protection materials (TPM) is described and compared to "standard" Space Shuttle TPM. This new functionally gradient material designated as Toughened Uni-Piece Fibrous Insulation (TUFI), was bonded on a removable panel attached to the base heat shield of Orbiter 105, Endeavour.

  6. Retrospective Analysis of NIST Standard Reference Material 1450, Fibrous Glass Board, for Thermal Insulation Measurements

    Science.gov (United States)

    Zarr, Robert R; Heckert, N Alan; Leigh, Stefan D

    2014-01-01

    Thermal conductivity data acquired previously for the establishment of Standard Reference Material (SRM) 1450, Fibrous Glass Board, as well as subsequent renewals 1450a, 1450b, 1450c, and 1450d, are re-analyzed collectively and as individual data sets. Additional data sets for proto-1450 material lots are also included in the analysis. The data cover 36 years of activity by the National Institute of Standards and Technology (NIST) in developing and providing thermal insulation SRMs, specifically high-density molded fibrous-glass board, to the public. Collectively, the data sets cover two nominal thicknesses of 13 mm and 25 mm, bulk densities from 60 kg·m−3 to 180 kg·m−3, and mean temperatures from 100 K to 340 K. The analysis repetitively fits six models to the individual data sets. The most general form of the nested set of multilinear models used is given in the following equation: λ(ρ,T)=a0+a1ρ+a2T+a3T3+a4e−(T−a5a6)2where λ(ρ,T) is the predicted thermal conductivity (W·m−1·K−1), ρ is the bulk density (kg·m−3), T is the mean temperature (K) and ai (for i = 1, 2, … 6) are the regression coefficients. The least squares fit results for each model across all data sets are analyzed using both graphical and analytic techniques. The prevailing generic model for the majority of data sets is the bilinear model in ρ and T. λ(ρ,T)=a0+a1ρ+a2T One data set supports the inclusion of a cubic temperature term and two data sets with low-temperature data support the inclusion of an exponential term in T to improve the model predictions. Physical interpretations of the model function terms are described. Recommendations for future renewals of SRM 1450 are provided. An Addendum provides historical background on the origin of this SRM and the influence of the SRM on external measurement programs. PMID:26601034

  7. Fibrous-Ceramic/Aerogel Composite Insulating Tiles

    Science.gov (United States)

    White, Susan M.; Rasky, Daniel J.

    2004-01-01

    Fibrous-ceramic/aerogel composite tiles have been invented to afford combinations of thermal-insulation and mechanical properties superior to those attainable by making tiles of fibrous ceramics alone or aerogels alone. These lightweight tiles can be tailored to a variety of applications that range from insulating cryogenic tanks to protecting spacecraft against re-entry heating. The advantages and disadvantages of fibrous ceramics and aerogels can be summarized as follows: Tiles made of ceramic fibers are known for mechanical strength, toughness, and machinability. Fibrous ceramic tiles are highly effective as thermal insulators in a vacuum. However, undesirably, the porosity of these materials makes them permeable by gases, so that in the presence of air or other gases, convection and gas-phase conduction contribute to the effective thermal conductivity of the tiles. Other disadvantages of the porosity and permeability of fibrous ceramic tiles arise because gases (e.g., water vapor or cryogenic gases) can condense in pores. This condensation contributes to weight, and in the case of cryogenic systems, the heat of condensation undesirably adds to the heat flowing to the objects that one seeks to keep cold. Moreover, there is a risk of explosion associated with vaporization of previously condensed gas upon reheating. Aerogels offer low permeability, low density, and low thermal conductivity, but are mechanically fragile. The basic idea of the present invention is to exploit the best features of fibrous ceramic tiles and aerogels. In a composite tile according to the invention, the fibrous ceramic serves as a matrix that mechanically supports the aerogel, while the aerogel serves as a low-conductivity, low-permeability filling that closes what would otherwise be the open pores of the fibrous ceramic. Because the aerogel eliminates or at least suppresses permeation by gas, gas-phase conduction, and convection, the thermal conductivity of such a composite even at

  8. Temperature and press load stimulation on thermal transport in fibrous and porous composite insulators

    International Nuclear Information System (INIS)

    Rehman, M.A.; Maqsood, A.

    2006-01-01

    Thermal transport properties of synthetic pliable insulators are measured as a function of applied pressure at constant temperatures. Advantageous Transient Plane Source (ATPS) method is used for the simultaneous measurement of thermal conductivity and thermal diffusivity of these materials and heat capacity per unit volume is then calculated. Three samples namely foam, closed cell foam and fiber glass are subjected to press load, taking into account the flexibility and sustainability of the samples and the requirements of the technique used. The thermal data of the samples were determined within the temperature range (300-414K) and pressure range (Normal -15kPa). These materials are used for thermal insulation and temperature control of air-conditioned space, acoustic and sound insulation, agriculture and fishery, sports and leisure goods, building and civil engineering, industrial packaging cold storage ware house, boiler work and other electric appliances, so they are helpful in reducing energy losses. (author)

  9. Thermal insulation

    International Nuclear Information System (INIS)

    Pinsky, G.P.

    1977-01-01

    Thermal insulation for vessels and piping within the reactor containment area of nuclear power plants is disclosed. The thermal insulation of this invention can be readily removed and replaced from the vessels and piping for inservice inspection, can withstand repeated wettings and dryings, and can resist high temperatures for long periods of time. 4 claims, 3 figures

  10. Thermal insulator

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, R.; Asada, Y.; Matsuo, Y.; Mikoda, M.

    1985-07-16

    A thermal insulator comprises an expanded resin body having embedded therein an evacuated powder insulation portion which consists of fine powder and a container of film-like plastics or a film-like composite of plastics and metal for enclosing the powder. The resin body has been expanded by a Freon gas as a blowing agent. Since a Freon gas has a larger molecular diameter than the constituent gases of air, it is less likely to permeate through the container than air. Thus present invention provides a novel composite insulator which fully utilizes the benefits of vacuum insulation without necessitating a strong and costly material for a vacuum container.

  11. Heat Transfer Modeling for Rigid High-Temperature Fibrous Insulation

    Science.gov (United States)

    Daryabeigi, Kamran; Cunnington, George R.; Knutson, Jeffrey R.

    2012-01-01

    Combined radiation and conduction heat transfer through a high-temperature, high-porosity, rigid multiple-fiber fibrous insulation was modeled using a thermal model previously used to model heat transfer in flexible single-fiber fibrous insulation. The rigid insulation studied was alumina enhanced thermal barrier (AETB) at densities between 130 and 260 kilograms per cubic meter. The model consists of using the diffusion approximation for radiation heat transfer, a semi-empirical solid conduction model, and a standard gas conduction model. The relevant parameters needed for the heat transfer model were estimated from steady-state thermal measurements in nitrogen gas at various temperatures and environmental pressures. The heat transfer modeling methodology was evaluated by comparison with standard thermal conductivity measurements, and steady-state thermal measurements in helium and carbon dioxide gases. The heat transfer model is applicable over the temperature range of 300 to 1360 K, pressure range of 0.133 to 101.3 x 10(exp 3) Pa, and over the insulation density range of 130 to 260 kilograms per cubic meter in various gaseous environments.

  12. Heat Transfer of Fibrous Insulation Battings

    Science.gov (United States)

    1984-01-01

    This was achiev the lower bulk-density regular fiber and the fine bulk-densities of the uncompressed higher bulk- de Sets of pb and d curves for the...34, J. of Thermal Insulation, Vol. 1, July, 1977, p. 49. 10. Mark, M., and Derecho , C. T., Jr., "Packing Coefficient and...Specification MIL-S-43880, Sleeping Bag, Extreme Cold (Down and Polyester Batting), 15 Mar 1979. 19. Breckenridge, J. R., "Insulating Effectiveness

  13. Combined Heat Transfer in High-Porosity High-Temperature Fibrous Insulations: Theory and Experimental Validation

    Science.gov (United States)

    Daryabeigi, Kamran; Cunnington, George R.; Miller, Steve D.; Knutson, Jeffry R.

    2010-01-01

    Combined radiation and conduction heat transfer through various high-temperature, high-porosity, unbonded (loose) fibrous insulations was modeled based on first principles. The diffusion approximation was used for modeling the radiation component of heat transfer in the optically thick insulations. The relevant parameters needed for the heat transfer model were derived from experimental data. Semi-empirical formulations were used to model the solid conduction contribution of heat transfer in fibrous insulations with the relevant parameters inferred from thermal conductivity measurements at cryogenic temperatures in a vacuum. The specific extinction coefficient for radiation heat transfer was obtained from high-temperature steady-state thermal measurements with large temperature gradients maintained across the sample thickness in a vacuum. Standard gas conduction modeling was used in the heat transfer formulation. This heat transfer modeling methodology was applied to silica, two types of alumina, and a zirconia-based fibrous insulation, and to a variation of opacified fibrous insulation (OFI). OFI is a class of insulations manufactured by embedding efficient ceramic opacifiers in various unbonded fibrous insulations to significantly attenuate the radiation component of heat transfer. The heat transfer modeling methodology was validated by comparison with more rigorous analytical solutions and with standard thermal conductivity measurements. The validated heat transfer model is applicable to various densities of these high-porosity insulations as long as the fiber properties are the same (index of refraction, size distribution, orientation, and length). Furthermore, the heat transfer data for these insulations can be obtained at any static pressure in any working gas environment without the need to perform tests in various gases at various pressures.

  14. Heat Transfer Modeling and Validation for Optically Thick Alumina Fibrous Insulation

    Science.gov (United States)

    Daryabeigi, Kamran

    2009-01-01

    Combined radiation/conduction heat transfer through unbonded alumina fibrous insulation was modeled using the diffusion approximation for modeling the radiation component of heat transfer in the optically thick insulation. The validity of the heat transfer model was investigated by comparison to previously reported experimental effective thermal conductivity data over the insulation density range of 24 to 96 kg/cu m, with a pressure range of 0.001 to 750 torr (0.1 to 101.3 x 10(exp 3) Pa), and test sample hot side temperature range of 530 to 1360 K. The model was further validated by comparison to thermal conductivity measurements using the transient step heating technique on an insulation sample at a density of 144 kg/cu m over a pressure range of 0.001 to 760 torr, and temperature range of 290 to 1090 K.

  15. Heat transfer enhancement of flow insulator by combined stainless steel fibrous and wire net porous materials

    Science.gov (United States)

    Khantikomol, P.; Polsongkram, M.; Apisitpinyo, W.; Poowadin, T.

    2018-01-01

    The present research article aims to propose the heat transfer enhancement of the flow insulator using combined fibrous and wire net stainless steel porous material. The stainless fibrous plate with porosity of 0.9292 was combined to the stainless steel wire net having pore per inch (PPI) of 16 and total thickness of 30 mm. Two models of the arranging porous plates were prepared, which were model BA and model AB. Each porous plate segment had the same thickness. The examined porous plate model have porosities of 0.8452. The porous plate was placed normal to the flow direction. The air was used as working fluid heated by 5 kW electric heater, which was controlled by the automatic temperature control. Type-K thermocouples were employed to measure the air temperatures. The temperature at front of the porous plate was varied to be 350, 450, and 550°C. The air flow rate was varied in the range of 4-12 m3/hr. The experimental result showed that the temperature drop across the porous plate and the thermal efficiency increase with the inlet temperature. The air velocity slightly affects the temperature profile inside the test section at the upstream side of the porous plate but greatly affects temperature inside the porous plate. In consideration of the arranging porous plate, placing of the stainless steel wire net at the upstream side and placing the stainless steel fibrous at downstream side (model BA) results in the highest temperature drop and the highest thermal efficiency. At Re 733 and inlet temperature 550°C for model BA at 30 mm thickness, the thermal efficiency was 50%. It was shown that the combined stainless steel fibrous and stainless steel wire net porous material could be a good flow insulator.

  16. Thermal/acoustical insulation foam

    Science.gov (United States)

    Lin, R. Y.; Struzik, E. A.

    1976-01-01

    Lightweight low-density substance can be used as fire resistant insulation in aircraft. Material density can be controlled over range from 0.6-1.2 pounds per cubic foot and has good thermal and acoustic properties.

  17. Thermal insulation blanket material

    Science.gov (United States)

    Pusch, R. H.

    1982-01-01

    A study was conducted to provide a tailorable advanced blanket insulation based on a woven design having an integrally woven core structure. A highly pure quartz yarn was selected for weaving and the cells formed were filled with a microquartz felt insulation.

  18. Multipurpose Thermal Insulation Test Apparatus

    Science.gov (United States)

    Fesmire, James E. (Inventor); Augustynowicz, Stanislaw D. (Inventor)

    2002-01-01

    A multi-purpose thermal insulation test apparatus is used for testing insulation materials, or other components. The test apparatus is a fluid boil-off calorimeter system for calibrated measurement of the apparent thermal conductivity (k-value) of a specimen material at a fixed vacuum level. The apparatus includes an inner vessel for receiving a fluid with a normal boiling point below ambient temperature, such as liquid nitrogen, enclosed within a vacuum chamber. A cold mass assembly, including the inner vessel and thermal guards, is suspended from the top of the vacuum chamber. Handling tools attach to the cold mass assembly for convenient manipulation of the assembly and for the installation or wrapping of insulation test materials. Liquid nitrogen is typically supplied to the inner vessel using a fill tube with funnel. A single port through the top of the vacuum chamber facilitates both filling and venting. Aerogel composite stacks with reflective films are fastened to the top and the bottom of the inner vessel as thermal guards. The comparative k-value of the insulation material is determined by measuring the boil-off flow rate of gas, the temperature differential across the insulation thickness, and the dimensions (length and diameters) of the test specimen.

  19. Reusable Surface Insulation Tile Thermal Protection Materials: Past, Present and the Future

    Science.gov (United States)

    Leiser, Daniel B.; Stewart, David A.; Venkatapathy, Ethiras (Technical Monitor)

    2002-01-01

    Silica (LI-900) Reusable Surface Insulation (RSI) tile have been used on the majority of the Shuttle since its initial flight. Its overall performance with Reaction Cured Glass (RCG) coating applied will be reviewed. Improvements in insulations, Fibrous Refractory Composite Insulation (FRCI-12) and Alumina Enhanced Thermal Barrier (AETB-8) and coatings/surface treatments such as Toughened Uni-Piece Fibrous Insulation (TUFI) have been developed and successfully applied. The performance of these enhancements on the Shuttle Orbiters over the past few years along with the next version of tile materials, High Efficiency Tantalum-based Ceramic (HETC) with even broader applicability will also be discussed.

  20. Thermal insulation of fuel elements

    International Nuclear Information System (INIS)

    Dubrovcak, P.; Pec, V.; Pitonak, J.

    1978-01-01

    The claim of the invention concerns thermal insulation of fuel elements heated for measurement of uranium fuel physical properties. For this, layers of aluminium film and of glass fibre are wound onto the inner tube of the element cladding. The space between the inner and the outer tubes is evacuated and the tubes are spaced using spacer wires. (M.S.)

  1. Ultralight, Thermally Insulating, Compressible Polyimide Fiber Assembled Sponges.

    Science.gov (United States)

    Jiang, Shaohua; Uch, Bianca; Agarwal, Seema; Greiner, Andreas

    2017-09-20

    Tunable density, thermally and mechanically stable, elastic, and thermally insulating sponges are required for demanding applications. Hierarchically structured sponges with bimodal interconnected pores, porosity more than 99%, and tunable densities (between 7.6 and 10.1 mg/cm 3 ) are reported using polyimide (PI) as high temperature stable polymer. The sponges are made by freeze-drying a dispersion of short PI fibers and precursor polymer, poly(amic acid) (PAA). The concept of "self-gluing" the fibrous network skeleton of PI during sponge formation was applied to achieve mechanical stability without sacrificing the thermal properties. The sponges showed initial degradation above 400 and 500 °C in air and nitrogen, respectively. They have low thermal conductivity of 0.026 W/mK and thermal diffusivity of 1.009 mm 2 /s for a density of 10.1 mg/cm 3 . The sponges are compressible for at least 10 000 cycles and good thermal insulators even at high compressions. These fibrous PI sponges are promising candidates for potential applications in thermal insulation, lightweight construction, high-temperature filtration, sensors, and catalyst carrier for high-temperature reactions.

  2. Selenide isotope generator for the Galileo Mission: SIG thermal insulation evaluaion tests

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    Since the SIG program required the use of very high performance thermal insulation materials in rather severe thermal and environmental conditions, a thorough screening and testing program was performed. Several types of materials were included in the preliminary survey. Most promising were oxide and carbonaceous fibrous insulations, oxide and carbonaceous foamed materials, and multilayer materials with both powder and cloth spacers. The latter were only viable for the vacuum option. In all, over one hundred materials from more than sixty manufacturers were evaluated from literature and manufacturers' data. The list was pared to eighteen candidates in seven basic types, i.e., fibrous microporous SiO/sub 2/, fibrous SiO/sub 2//Al/sub 2/O/sub 3/, fibrous ZrO/sub 2/, fibrous carbon, foamed SiO/sub 2/, foamed carbon, and multilayer. Test results are presented.

  3. Passive Collecting of Solar Radiation Energy using Transparent Thermal Insulators, Energetic Efficiency of Transparent Thermal Insulators

    Directory of Open Access Journals (Sweden)

    Smajo Sulejmanovic

    2014-11-01

    Full Text Available This paper explains passive collection of solar radiation energy using transparent thermal insulators. Transparent thermal insulators are transparent for sunlight, at the same time those are very good thermal insulators. Transparent thermal insulators can be placed instead of standard conventional thermal insulators and additionally transparent insulators can capture solar radiation, transform it into heat and save heat just as standard insulators. Using transparent insulators would lead to reduce in usage of fossil fuels and would help protection of an environment and reduce effects of global warming, etc.

  4. Transient Thermal Testing and Analysis of a Thermally Insulating Structural Sandwich Panel

    Science.gov (United States)

    Blosser, Max L.; Daryabeigi, Kamran; Bird, Richard K.; Knutson, Jeffrey R.

    2015-01-01

    A core configuration was devised for a thermally insulating structural sandwich panel. Two titanium prototype panels were constructed to illustrate the proposed sandwich panel geometry. The core of one of the titanium panels was filled with Saffil(trademark) alumina fibrous insulation and the panel was tested in a series of transient thermal tests. Finite element analysis was used to predict the thermal response of the panel using one- and two-dimensional models. Excellent agreement was obtained between predicted and measured temperature histories.

  5. Thermal insulation properties of walls

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2014-05-01

    Full Text Available Heat-protective qualities of building structures are determined by the qualities of the used materials, adequate design solutions and construction and installation work of high quality. This rule refers both to the structures made of materials similar in their structure and nature and mixed, combined by a construction system. The necessity to ecaluate thermal conductivity is important for a product and for a construction. Methods for evaluating the thermal protection of walls are based on the methods of calculation, on full-scale tests in a laboratory or on objects. At the same time there is a reason to believe that even deep and detailed calculation may cause deviation of the values from real data. Using finite difference method can improve accuracy of the results, but it doesn’t solve all problems. The article discusses new approaches to evaluating thermal insulation properties of walls. The authors propose technique of accurate measurement of thermal insulation properties in single blocks and fragments of walls and structures.

  6. Local Thermal Insulating Materials For Thermal Energy Storage ...

    African Journals Online (AJOL)

    Thermal insulation is one of the most important components of a thermal energy storage system. In this paper the thermal properties of selected potential local materials which can be used for high temperature insulation are presented. Thermal properties of seven different samples were measured. Samples consisted of: ...

  7. Quantitative analysis of thermal insulation coatings

    DEFF Research Database (Denmark)

    Kiil, Søren

    2014-01-01

    This work concerns the development of simulation tools for mapping of insulation properties of thermal insulation coatings based on selected functional filler materials. A mathematical model, which includes the underlying physics (i.e. thermal conductivity of a heterogeneous two-component coating...

  8. Comparative study of hygrothermal properties of five thermal insulation materials

    Directory of Open Access Journals (Sweden)

    Laure Ducoulombier

    2017-09-01

    Full Text Available The objective of this article is to carry out a comparative study of the main hygrothermal properties of five thermal insulation materials for buildings. These properties are necessary for a correct prediction of heat and moisture transfers through the walls and the selection of the most appropriate materials according to the specific buildings. The studied materials were glass wool, rock wool, expanded polystyrene, wood fiberboard and polyester fiberfill. The article is divided into three parts. The first part presents the phenomena of hygrothermal transfers in walls in order to understand the need for determining specific properties of the insulating materials. The second part describes in details the five studied insulating materials and the methods used for the characterization and identification of their main properties. Finally, the last part presents the experimental results and makes comparisons between materials. The differences between the insulating materials are brought out, such as the strong dependence of the thermal conductivity of polystyrene on temperature, or the good permeability of fibrous insulating materials to water vapor. A detailed analysis of the obtained results is presented.

  9. Thermal Insulation Strips Conserve Energy

    Science.gov (United States)

    2009-01-01

    Launching the space shuttle involves an interesting paradox: While the temperatures inside the shuttle s main engines climb higher than 6,000 F hot enough to boil iron for fuel, the engines use liquid hydrogen, the second coldest liquid on Earth after liquid helium. Maintained below 20 K (-423 F), the liquid hydrogen is contained in the shuttle s rust-colored external tank. The external tank also contains liquid oxygen (kept below a somewhat less chilly 90 K or -297 F) that combines with the hydrogen to create an explosive mixture that along with the shuttle s two, powdered aluminum-fueled solid rocket boosters allows the shuttle to escape Earth s gravity. The cryogenic temperatures of the main engines liquid fuel can cause ice, frost, or liquefied air to build up on the external tank and other parts of the numerous launch fueling systems, posing a possible debris risk when the ice breaks off during launch and causing difficulties in the transfer and control of these cryogenic liquid propellants. Keeping the fuel at the necessary ultra-cold temperatures while minimizing ice buildup and other safety hazards, as well as reducing the operational maintenance costs, has required NASA to explore innovative ways for providing superior thermal insulation systems. To address the challenge, the Agency turned to an insulating technology so effective that, even though it is mostly air, a thin sheet can prevent a blowtorch from igniting a match. Aerogels were invented in 1931 and demonstrate properties that make them the most extraordinary insulating materials known; a 1-inch-thick piece of aerogel provides the same insulation as layering 15 panes of glass with air pockets in between. Derived from silica, aluminum oxide, or carbon gels using a supercritical drying process - resulting in a composition of almost 99-percent air - aerogels are the world s lightest solid (among 15 other titles they hold in the Guinness World Records), can float indefinitely on water if treated to be

  10. A Parametric Study of Thermal Performance of an Exterior Wall Insulated with Vacuum Insulation Panels

    OpenAIRE

    Ciobanu, Adrian-Alexandru; Iacob, Adrian

    2013-01-01

    The requirements regarding thermal insulation of the new buildings and thermal rehabilitation of the existing buildings tend to reach a threshold of insulation which allows to fulfill the necessary requirements for a low-energy building. To achieve this level of thermal insulation involves using either thick layers of conventional insulation (polystyrene, mineral wool, etc.) or high thermal performance materials. Vacuum insulation panels are high performance thermal insulation characteri...

  11. Thermal insulation of high temperature reactors

    International Nuclear Information System (INIS)

    Cornille, Y.

    1975-01-01

    Operating conditions of HTR thermal insulation are given and heat insulators currently developed are described (fibers kept in position by metallic structures). For future applications and higher temperatures, research is directed towards solutions using ceramics or associating fibers and ceramics [fr

  12. Evaluation of different measurements for effective thermal conductivity of fibrous materials

    Directory of Open Access Journals (Sweden)

    Tian Ming-Wei

    2014-01-01

    Full Text Available Effective thermal conductivity is generally recognized as the intrinsic factor to reveal the thermal responses of fibrous materials. Here, two typical measurements, the step-wise transient method and the guarded hot plate method, were utilized to identify their feasibility for the effective thermal conductivity of fibrous materials (non-woven fabric and twill fabric with different stacking layers.

  13. Evaluation of thermal insulation materials

    Science.gov (United States)

    Wilbers, O. J.; Conti, J. C.; Mcgee, J. V.; Mcpherson, J. I.

    1973-01-01

    Data was obtained on silicone-bonded fiberglass, isocyanurate foam, and two dozen other insulators. Materials were selected to withstand heat sterilization, outer space, and the Martian atmosphere. Significant environmental parameters were vibration, landing shock, and launch venting.

  14. Thermal Performance Testing of Cryogenic Insulation Systems

    Science.gov (United States)

    Fesmire, James E.; Augustynowicz, Stan D.; Scholtens, Brekke E.

    2007-01-01

    Efficient methods for characterizing thermal performance of materials under cryogenic and vacuum conditions have been developed. These methods provide thermal conductivity data on materials under actual-use conditions and are complementary to established methods. The actual-use environment of full temperature difference in combination with vacuum-pressure is essential for understanding insulation system performance. Test articles include solids, foams, powders, layered blankets, composite panels, and other materials. Test methodology and apparatus design for several insulation test cryostats are discussed. The measurement principle is liquid nitrogen boil-off calorimetry. Heat flux capability ranges from approximately 0.5 to 500 watts per square meter; corresponding apparent thermal conductivity values range from below 0.01 up to about 60 mW/m- K. Example data for different insulation materials are also presented. Upon further standardization work, these patented insulation test cryostats can be available to industry for a wide range of practical applications.

  15. A theoretical analysis of local thermal equilibrium in fibrous materials

    Directory of Open Access Journals (Sweden)

    Tian Mingwei

    2015-01-01

    Full Text Available The internal heat exchange between each phase and the Local Thermal Equilibrium (LTE scenarios in multi-phase fibrous materials are considered in this paper. Based on the two-phase heat transfer model, a criterion is proposed to evaluate the LTE condition, using derived characteristic parameters. Furthermore, the LTE situations in isothermal/adiabatic boundary cases with two different heat sources (constant heat flux and constant temperature are assessed as special transient cases to test the proposed criterion system, and the influence of such different cases on their LTE status are elucidated. In addition, it is demonstrated that even the convective boundary problems can be generally estimated using this approach. Finally, effects on LTE of the material properties (thermal conductivity, volumetric heat capacity of each phase, sample porosity and pore hydraulic radius are investigated, illustrated and discussed in our study.

  16. Thermal insulation materials for inside applications: Hygric and thermal properties

    Science.gov (United States)

    Jerman, Miloš; Černý, Robert

    2017-11-01

    Two thermal insulation materials suitable for the application on the interior side of historical building envelopes, namely calcium silicate and polyurethane-based foam are studied. Moisture diffusivity and thermal conductivity of both materials, as fundamental moisture and heat transport parameters, are measured in a dependence on moisture content. The measured data will be used as input parameters in computer simulation studies which will provide moisture and temperature fields necessary for an appropriate design of interior thermal insulation systems.

  17. 14 CFR 25.856 - Thermal/Acoustic insulation materials.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Thermal/Acoustic insulation materials. 25....856 Thermal/Acoustic insulation materials. (a) Thermal/acoustic insulation material installed in the.../acoustic insulation materials (including the means of fastening the materials to the fuselage) installed in...

  18. Low-Density, Sprayable, Thermal Insulation

    Science.gov (United States)

    Mclemore, James P.; Norton, William E.; Lambert, Joe D.; Simpson, William G.; Echols, Sherman; Sharpe, Max H.; Hill, William E.

    1989-01-01

    Improved formulation prevents cracks. Low-density, thermally insulating material applied by spraying it onto surface to be protected. Material, called "MSA-2" improved version of similar material called "MSA-1". Useful as sprayed, lightweight insulation to cover large areas in terrestrial applications in which manual attachment too slow or impractical. Formulated to be more flexible and to prevent coats as thick as 1/2 in. from developing stress cracks as they cure.

  19. Nuclear reactor vessel fuel thermal insulating barrier

    Energy Technology Data Exchange (ETDEWEB)

    Keegan, C. Patrick; Scobel, James H.; Wright, Richard F.

    2013-03-19

    The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel that has a hemispherical lower section that increases in volume from the center line of the reactor to the outer extent of the diameter of the thermal insulating barrier and smoothly transitions up the side walls of the vessel. The space between the thermal insulating harrier and the reactor vessel forms a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive inlet valve for the cooling water includes a buoyant door that is normally maintained sealed under its own weight and floats open when the cavity is Hooded. Passively opening steam vents are also provided.

  20. Optically Transparent Thermally Insulating Silica Aerogels for Solar Thermal Insulation.

    Science.gov (United States)

    Günay, A Alperen; Kim, Hannah; Nagarajan, Naveen; Lopez, Mateusz; Kantharaj, Rajath; Alsaati, Albraa; Marconnet, Amy; Lenert, Andrej; Miljkovic, Nenad

    2018-04-18

    Rooftop solar thermal collectors have the potential to meet residential heating demands if deployed efficiently at low solar irradiance (i.e., 1 sun). The efficiency of solar thermal collectors depends on their ability to absorb incoming solar energy and minimize thermal losses. Most techniques utilize a vacuum gap between the solar absorber and the surroundings to eliminate conduction and convection losses, in combination with surface coatings to minimize reradiation losses. Here, we present an alternative approach that operates at atmospheric pressure with simple, black, absorbing surfaces. Silica based aerogels coated on black surfaces have the potential to act as simple and inexpensive solar thermal collectors because of their high transmission to solar radiation and low transmission to thermal radiation. To demonstrate their heat-trapping properties, we fabricated tetramethyl orthosilicate-based silica aerogels. A hydrophilic aerogel with a thickness of 1 cm exhibited a solar-averaged transmission of 76% and thermally averaged transmission of ≈1% (at 100 °C). To minimize unwanted solar absorption by O-H groups, we functionalized the aerogel to be hydrophobic, resulting in a solar-averaged transmission of 88%. To provide a deeper understanding of the link between aerogel properties and overall efficiency, we developed a coupled radiative-conductive heat transfer model and used it to predict solar thermal performance. Instantaneous solar thermal efficiencies approaching 55% at 1 sun and 80 °C were predicted. This study sheds light on the applicability of silica aerogels on black coatings for solar thermal collectors and offers design priorities for next-generation solar thermal aerogels.

  1. Thermal/acoustical aircraft insulation material

    Science.gov (United States)

    Struzik, E. A.; Kunz, R.; Lin, R.

    1975-01-01

    Attempts made to improve the acoustical properties of low density Fiberfrax foam, an aircraft insulation material, are reported. Characterizations were also made of the physical and thermal properties. Two methods, optimization of fiber blend composition and modification of the foam fabrication process, were examined as possible means of improving foam acoustics. Flame impingement tests were also made; results show performance was satisfactory.

  2. Aerogel Beads as Cryogenic Thermal Insulation System

    Science.gov (United States)

    Fesmire, J. E.; Augustynowicz, S. D.; Rouanet, S.; Thompson, Karen (Technical Monitor)

    2001-01-01

    An investigation of the use of aerogel beads as thermal insulation for cryogenic applications was conducted at the Cryogenics Test Laboratory of NASA Kennedy Space Center. Steady-state liquid nitrogen boiloff methods were used to characterize the thermal performance of aerogel beads in comparison with conventional insulation products such as perlite powder and multilayer insulation (MLI). Aerogel beads produced by Cabot Corporation have a bulk density below 100 kilograms per cubic meter (kg/cubic m) and a mean particle diameter of 1 millimeter (mm). The apparent thermal conductivity values of the bulk material have been determined under steady-state conditions at boundary temperatures of approximately 293 and 77 kelvin (K) and at various cold vacuum pressures (CVP). Vacuum levels ranged from 10(exp -5) torr to 760 torr. All test articles were made in a cylindrical configuration with a typical insulation thickness of 25 mm. Temperature profiles through the thickness of the test specimens were also measured. The results showed the performance of the aerogel beads was significantly better than the conventional materials in both soft-vacuum (1 to 10 torr) and no-vacuum (760 torr) ranges. Opacified aerogel beads performed better than perlite powder under high-vacuum conditions. Further studies for material optimization and system application are in progress.

  3. Building ceramics with improved thermal insulation parameters

    Directory of Open Access Journals (Sweden)

    Rzepa Karol

    2016-01-01

    Full Text Available One of the most important performance characteristics of masonry units is their high thermal insulation. There are many different ways to improve this parameter, however the most popular methods in case of ceramic masonry units are: addition of pore-creating raw materials and application of proper hole pattern. This study was an attempt to improve thermal insulation of ceramics by applying thermal insulation additives. Perlite dust created as a subgrain from expansion of perlite rock was used. Perlite subgrain is not very popular among consumers, that’s why it’s subjected to granulation to obtain coarse grain. The authors presented concept of direct application of perlite dust for the production of building ceramics with improved thermal insulation. Fineness of this additive is asset for molding of ceramic materials from plastic masses. Based on the results it was found that about 70% perlite by volume can be added to obtain material with a coefficient of heat conductivity of 0,37 W/mK. Higher content of this additive in ceramic mass causes deterioration of its rheological properties. Mass loses its plasticity, it tears up and formed green bodies are susceptible to deformation. During sintering perlite takes an active part in compaction process. Higher sintering dynamics is caused by: high content of alkali oxides in perlite and glass nature of perlite. Alkali oxides generate creation of liquid phase which intensifies mass compaction processes. Active role of perlite in sintering process causes good connection of its grains with clay groundwork which is important factor for mechanical parameters of ceramic materials. It was also noted that addition of perlite above 40% by volume of mass effectively neutralized negative effect of efflorescence in ceramic materials.

  4. Overview of thermal conductivity models of anisotropic thermal insulation materials

    Science.gov (United States)

    Skurikhin, A. V.; Kostanovsky, A. V.

    2017-11-01

    Currently, the most of existing materials and substances under elaboration are anisotropic. It makes certain difficulties in the study of heat transfer process. Thermal conductivity of the materials can be characterized by tensor of the second order. Also, the parallelism between the temperature gradient vector and the density of heat flow vector is violated in anisotropic thermal insulation materials (TIM). One of the most famous TIM is a family of integrated thermal insulation refractory material («ITIRM»). The main component ensuring its properties is the «inflated» vermiculite. Natural mineral vermiculite is ground into powder state, fired by gas burner for dehydration, and its precipitate is then compressed. The key feature of thus treated batch of vermiculite is a package structure. The properties of the material lead to a slow heating of manufactured products due to low absorption and high radiation reflection. The maximum of reflection function is referred to infrared spectral region. A review of current models of heat propagation in anisotropic thermal insulation materials is carried out, as well as analysis of their thermal and optical properties. A theoretical model, which allows to determine the heat conductivity «ITIRM», can be useful in the study of thermal characteristics such as specific heat capacity, temperature conductivity, and others. Materials as «ITIRM» can be used in the metallurgy industry, thermal energy and nuclear power-engineering.

  5. Thermally-insulating layer for nuclear reactors

    International Nuclear Information System (INIS)

    1975-01-01

    The thermally-insulating layer has been designed both for insulating surfaces within the core of a nuclear reactor and transmitting loads such as the core-weight. Said layer comprises a layer of bricks and a layer of tiles with smaller clearance between the tiles than between the bricks, the latter having a reduced cross-section against the tiles so as to be surrounded by relatively large interconnected ducts forming a continuous chamber behind the tile-layer in order to induce a substantial decreases in the transverse flow of the reactor-core coolant. The core preferably comprises hexagonal columns supported by rhomb-shaped plates, with channels distributed so as to mix the coolant of twelve columns. The plates are separated from support-tiles by means of pillars [fr

  6. Advances in Thermal Insulation. Vacuum Insulation Panels and Thermal Efficiency to Reduce Energy Usage in Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Thorsell, Thomas

    2012-07-01

    We are coming to realize that there is an urgent need to reduce energy usage in buildings and it has to be done in a sustainable way. This thesis focuses on the performance of the building envelope; more precisely thermal performance of walls and super insulation material in the form of vacuum insulation. However, the building envelope is just one part of the whole building system, and super insulators have one major flaw: they are easily adversely affected by other problems in the built environment. Vacuum Insulation Panels are one fresh addition to the arsenal of insulation materials available to the building industry. They are composite material with a core and an enclosure which, as a composite, can reach thermal conductivities as low as 0.004 W/(mK). However, the exceptional performance relies on the barrier material preventing gas permeation, maintaining a near vacuum into the core and a minimized thermal bridge effect from the wrapping of barrier material round the edge of a panel. A serpentine edge is proposed to decrease the heat loss at the edge. Modeling and testing shows a reduction of 60 % if a reasonable serpentine edge is used. A diffusion model of permeation through multilayered barrier films with metallization coatings was developed to predict ultimate service life. The model combines numerical calculations with analytical field theory allowing for more precise determination than current models. The results using the proposed model indicate that it is possible to manufacture panels with lifetimes exceeding 50 years with existing manufacturing. Switching from the component scale to the building scale; an approach of integrated testing and modeling is proposed. Four wall types have been tested in a large range of environments with the aim to assess the hydrothermal nature and significance of thermal bridges and air leakages. The test procedure was also examined as a means for a more representative performance indicator than R-value (in USA). The

  7. comparative study of thermal insulation boards from leaf and bark ...

    African Journals Online (AJOL)

    HOD

    environmentally friendly thermal insulation products. The aim of this study was to compare the performance of insulation boards made from leave and bark fibres of Piliostigma thonningii L.in terms of density, water absorption, apparent thermal conductivity, specific heat and thermal diffusivity. The leave and the bark fibres ...

  8. Analysis and Experimental on Aircraft Insulation Thermal Bridge Effect

    Directory of Open Access Journals (Sweden)

    XIA Tian

    2017-06-01

    Full Text Available Two kinds of typical aircraft insulation structures were designed for the heat bridge in the metal ribs of aircraft insulation structures. In order to study the influence of heat bridge effect on thermal insulation performance, each configuration was analyzed by the transient heat transfer FEA, check point temperature was obtained in the hot surface temperature of 100 ℃, 200 ℃, 300 ℃, 424 ℃ respectively, and the validity of FEA was proved by insulation performance experiment. The result showed that the thermal bridge has a great influence to the insulation performance of insulation structure, and the thermal bridge influence should be considered adequately when the insulation structure designed. Additionally, the blocking method for thermal bridge is also put forward.

  9. Thermally insulating and fire-retardant lightweight anisotropic foams based on nanocellulose and graphene oxide

    Science.gov (United States)

    Wicklein, Bernd; Kocjan, Andraž; Salazar-Alvarez, German; Carosio, Federico; Camino, Giovanni; Antonietti, Markus; Bergström, Lennart

    2015-03-01

    High-performance thermally insulating materials from renewable resources are needed to improve the energy efficiency of buildings. Traditional fossil-fuel-derived insulation materials such as expanded polystyrene and polyurethane have thermal conductivities that are too high for retrofitting or for building new, surface-efficient passive houses. Tailored materials such as aerogels and vacuum insulating panels are fragile and susceptible to perforation. Here, we show that freeze-casting suspensions of cellulose nanofibres, graphene oxide and sepiolite nanorods produces super-insulating, fire-retardant and strong anisotropic foams that perform better than traditional polymer-based insulating materials. The foams are ultralight, show excellent combustion resistance and exhibit a thermal conductivity of 15 mW m-1 K-1, which is about half that of expanded polystyrene. At 30 °C and 85% relative humidity, the foams retained more than half of their initial strength. Our results show that nanoscale engineering is a promising strategy for producing foams with excellent properties using cellulose and other renewable nanosized fibrous materials.

  10. Prospect of Thermal Insulation by Silica Aerogel: A Brief Review

    Science.gov (United States)

    Hasan, Mohammed Adnan; Sangashetty, Rashmi; Esther, A. Carmel Mary; Patil, Sharanabasappa B.; Sherikar, Baburao N.; Dey, Arjun

    2017-10-01

    Silica aerogel is a unique ultra light weight nano porous material which offers superior thermal insulation property as compared to the conventional thermal insulating materials. It can be applied not only for ground and aerospace applications but also in low and high temperatures and pressure regimes. Aerogel granules and monolith are synthesized by the sol-gel route while aerogel based composites are fabricated by the reinforcement of fibers, particle and opacifiers. Due to the characteristic brittleness (i.e., poor mechanical properties) of monolith or bulk aerogel, it is restricted in several applications. To improve the mechanical integrity and flexibility, usually different fibers are reinforced with aerogel and hence it can be used as flexible thermal insulation blankets. Further, to achieve effective thermal insulation behaviour particularly at high temperature, often opacifiers are doped with silica aerogel. In the present brief review, the prospects of bulk aerogel and aerogel based composites are discussed for the application of thermal insulation and thermal stability.

  11. Sprayable Thermal Insulation for Cryogenic Tanks, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The Sprayable Thermal Insulation for Cryogenic Tanks (STICT) is a thermal management system applied by either an automated or manual spraying process with less...

  12. Preparation of a Novel Water-based Acrylic Multi-Thermal Insulation Coating

    OpenAIRE

    Xiufang YE; Dongchu CHEN; Menglei CHANG; Youtian MO; Qingxiang WANG

    2017-01-01

    To efficiently improve the thermal insulation effect of coatings, a novel water-based acrylic multi-thermal insulation coating (multi-WATIC) combined with thermal obstruction, echo, and radiation was prepared. The category and ratio of thermal insulation functional fillers are crucial. First, water-based acrylic thermal insulation coating (WATIC) with single thermal insulation functional fillers was prepared, and the thermal insulation property tests were done. Thereafter, a novel multi-WATIC...

  13. THERMAL INSULATION EFFECTS ON ENERGY EFFICIENCY OF BUILDING STRUCTURES

    Directory of Open Access Journals (Sweden)

    M. Cvetkovska

    2012-05-01

    Full Text Available This paper presents the use of Finite Element Method for heat transfer analysis. Connections wall-beam-floor structures with different positions of the thermal insulation have been analyzed and conclusions about energy efficiency and energy loss are made. Keywords: heat transfer, numerical analysis, finite elements, thermal insulation, energy efficiency.

  14. The Wick-Concept for Thermal Insulation of Cold Piping

    DEFF Research Database (Denmark)

    Koverdynsky, Vit; Korsgaard, Vagn; Rode, Carsten

    2006-01-01

    The wick-concept for thermal insulation of cold piping is based on capillary suction of a fiber fabric to remove excess water from the pipe surface by transporting it to the outer surface of the insulation. From the surface of the insulation jacket, the water will evaporate to the ambient air....... This will prevent long-term accumulation of moisture in the insulation material. The wick keeps the hydrophobic insulation dry, allowing it to maintain its thermal performance. The liquid moisture is kept only in the wick fabric. This article presents the principle of operation of cold pipe insulation using...... that the variations of these types of insulation systems work for pipes with temperature above 0C and for ambient conditions within common ranges for industrial applications....

  15. Сombined Thermal Insulating Module of Mounted Vented Facades

    Directory of Open Access Journals (Sweden)

    Ryabukhina Svetlana

    2016-01-01

    Full Text Available In order to define an optimum type of mounted vented facades among the existing ones, comparative analysis of two façade modules has been conducted. The first module type is a widespread standard module of hinged vented facade and the second type is less applicable combined thermal insulating module. Those two technologies were compared thermal engineering and energy efficiency parameters. It was defined that the application of a thermal insulating module with combined insulation system improves thermal engineering parameters of the building as well as leads to a substantial savings. This article exposes innovative materials and structure of vented facades which can be applied in modern construction.

  16. Environmental safety providing during heat insulation works and using thermal insulation materials

    Directory of Open Access Journals (Sweden)

    Velichko Evgeny

    2017-01-01

    Full Text Available This article considers the negative effect of thermal insulating materials and products on human health and environment pollution, particularly in terms of the composition of environmentally hazardous construction products. The authors have analyzed the complex measures for providing ecological safety, sanitary and epidemiological requirements, rules and regulations both during thermal insulation works and throughout the following operation of buildings and premises. The article suggests the protective and preventive measures to reduce and eliminate the negative impact of the proceeding of thermal insulation works on the natural environment and on human health.

  17. Thermal-Insulation Properties of Multilayer Textile Packages

    Directory of Open Access Journals (Sweden)

    Matusiak Małgorzata

    2014-12-01

    Full Text Available Thermal-insulation properties of textile materials play a significant role in material engineering of protective clothing. Thermal-insulation properties are very important from the point of view of thermal comfort of the clothing user as well as the protective efficiency against low or high temperature. Thermal protective clothing usually is a multilayer construction. Its thermal insulation is a resultant of a number of layers and their order, as well as the thermalinsulation properties of a single textile material creating particular layers. The aim of the presented work was to investigate the relationships between the thermal-insulation properties of single materials and multilayer textile packages composed of these materials. Measurement of the thermal-insulation properties of single and multilayer textile materials has been performed with the Alambeta. The following properties have been investigated: thermal conductivity, resistance and absorptivity. Investigated textile packages were composed of two, three and four layers made of woven and knitted fabrics, as well as nonwovens. On the basis of the obtained results an analysis has been carried out in order to assess the dependency of the resultant values of the thermal-insulation properties of multilayer packages on the appropriate values of particular components.

  18. The Wick-Concept for Thermal Insulation of Cold Piping

    DEFF Research Database (Denmark)

    Koverdynsky, Vit; Korsgaard, Vagn; Rode, Carsten

    2006-01-01

    the wick-concept in either of two variations: the self-drying or the self-sealing system. Experiments have been carried out using different variations of the two systems to investigate the conditions for exploiting the drying capabilities of the systems, and the results are presented. The results show......The wick-concept for thermal insulation of cold piping is based on capillary suction of a fiber fabric to remove excess water from the pipe surface by transporting it to the outer surface of the insulation. From the surface of the insulation jacket, the water will evaporate to the ambient air....... This will prevent long-term accumulation of moisture in the insulation material. The wick keeps the hydrophobic insulation dry, allowing it to maintain its thermal performance. The liquid moisture is kept only in the wick fabric. This article presents the principle of operation of cold pipe insulation using...

  19. Thermally assisted ordering in Mott insulators

    Science.gov (United States)

    Sims, Hunter; Pavarini, Eva; Koch, Erik

    2017-08-01

    Landau theory describes phase transitions as the competition between energy and entropy: The ordered phase has lower energy, while the disordered phase has larger entropy. When heating the system, ordering is reduced entropically until it vanishes at the critical temperature. This picture implicitly assumes that the energy difference between the ordered and disordered phases does not change with temperature. We show that for orbital ordering in the Mott insulator KCuF3, this assumption fails qualitatively: entropy plays a negligible role, while thermal expansion energetically stabilizes the orbitally ordered phase to such an extent that no phase transition is observed. To understand this strong dependence on the lattice constant, we need to take into account the Born-Mayer repulsion between the ions. It is the latter, and not the Jahn-Teller elastic energy, which determines the magnitude of the distortion. This effect will be seen in all materials where the distortion expected from the Jahn-Teller mechanism is so large that the ions would touch. Our mechanism explains not only the absence of a phase transition in KCuF3, but even suggests the possibility of an inverted transition in closed-shell systems, where the ordered phase emerges only at high temperatures.

  20. Sprayable Thermal Insulation for Cryogenic Tanks, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation addressed in this proposal is Sprayable Thermal Insulation for Cryogenic Tanks, or STICT. This novel system could be applied in either an automated or...

  1. Alkali-bonded composites for thermal and acoustic insulation

    OpenAIRE

    Medri, Valentina

    2012-01-01

    Geopolymers are alkali bonded ceramics that thank to their fully inolrganic nature have high temperature resistance depending on their compositions. An overview of the research of ISTEC on Alkali-bonded composites for thermal and acoustic insulation have been presented

  2. Development of a thermal acoustical aircraft insulation material

    Science.gov (United States)

    Lin, R. Y.; Struzik, E. A.

    1974-01-01

    A process was developed for fabricating a light weight foam suitable for thermal and acoustical insulation in aircraft. The procedures and apparatus are discussed, and the foam specimens are characterized by numerous tests and measurements.

  3. Thermal performances of an insulating structure for a reactor vessel

    International Nuclear Information System (INIS)

    Aranovitch, E.; Crutzen, S.; Le Det, M.; Denis, R.

    1974-12-01

    This report describes the thermal and technological tests performed on a multilayer thermal insulation system for high temperature gas reactors. It includes the description of test facilities, global tests, interpretation of data, and technological tests. Results obtained make it possible to predetermine with a satisfactory precision thermal performances under various nominal conditions

  4. Outgassing of solid material into vacuum thermal insulation spaces

    Science.gov (United States)

    Wang, Pao-Lien

    1994-01-01

    Many cryogenic storage tanks use vacuum between inner and outer tank for thermal insulation. These cryogenic tanks also use a radiation shield barrier in the vacuum space to prevent radiation heat transfer. This shield is usually constructed by using multiple wraps of aluminized mylar and glass paper as inserts. For obtaining maximum thermal performance, a good vacuum level must be maintained with the insulation system. It has been found that over a period of time solid insulation materials will vaporize into the vacuum space and the vacuum will degrade. In order to determine the degradation of vacuum, the rate of outgassing of the insulation materials must be determined. Outgassing rate of several insulation materials obtained from literature search were listed in tabular form.

  5. Parametric Investigation of Optimum Thermal Insulation Thickness for External Walls

    Directory of Open Access Journals (Sweden)

    Omer Kaynakli

    2011-06-01

    Full Text Available Numerous studies have estimated the optimum thickness of thermal insulation materials used in building walls for different climate conditions. The economic parameters (inflation rate, discount rate, lifetime and energy costs, the heating/cooling loads of the building, the wall structure and the properties of the insulation material all affect the optimum insulation thickness. This study focused on the investigation of these parameters that affect the optimum thermal insulation thickness for building walls. To determine the optimum thickness and payback period, an economic model based on life-cycle cost analysis was used. As a result, the optimum thermal insulation thickness increased with increasing the heating and cooling energy requirements, the lifetime of the building, the inflation rate, energy costs and thermal conductivity of insulation. However, the thickness decreased with increasing the discount rate, the insulation material cost, the total wall resistance, the coefficient of performance (COP of the cooling system and the solar radiation incident on a wall. In addition, the effects of these parameters on the total life-cycle cost, payback periods and energy savings were also investigated.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-01

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

  7. Thermal Transport in High-Strength Polymethacrylimide (PMI) Foam Insulations

    Science.gov (United States)

    Qiu, L.; Zheng, X. H.; Zhu, J.; Tang, D. W.; Yang, S. Y.; Hu, A. J.; Wang, L. L.; Li, S. S.

    2015-11-01

    Thermal transport in high-strength polymethacrylimide (PMI) foam insulations is described, with special emphasis on the density and temperature effects on the thermal transport performance. Measurements of the effective thermal conductivity are performed by a freestanding sensor-based 3ω method. A linear relationship between the density and the effective thermal conductivity is observed. Based on the analysis of the foam insulation morphological structures and the corresponding geometrical cell model, the quantitative contribution of the solid conductivity and the gas conductivity as well as the radiative conductivity to the total effective thermal conductivity as a function of the density and temperature is calculated. The agreement between the curves of the results from the developed model and experimental data indicate the model can be used for PMI foam insulating performance optimization.

  8. Improved Thermal-Insulation Systems for Low Temperatures

    Science.gov (United States)

    Fesmire, James E.; Augustynowicz, Stanislaw D.

    2003-01-01

    Improved thermal-insulation materials and structures and the techniques for manufacturing them are undergoing development for use in low-temperature applications. Examples of low-temperature equipment for which these thermal insulation systems could provide improved energy efficiency include storage tanks for cryogens, superconducting electric-power-transmission equipment, containers for transport of food and other perishable commodities, and cold boxes for low-temperature industrial processes. These systems could also be used to insulate piping used to transfer cryogens and other fluids, such as liquefied natural gas, refrigerants, chilled water, crude oil, or low-pressure steam. The present thermal-insulation systems are layer composites based partly on the older class of thermal-insulation systems denoted generally as multilayer insulation (MLI). A typical MLI structure includes an evacuated jacket, within which many layers of radiation shields are stacked or wrapped close together. Low-thermal-conductivity spacers are typically placed between the reflection layers to keep them from touching. MLI can work very well when a high vacuum level (less than 10(exp-4) torr) is maintained and utmost care is taken during installation, but its thermal performance deteriorates sharply as the pressure in the evacuated space rises into the soft vacuum range [pressures greater than 0.1 torr (greater than 13 Pa)]. In addition, the thermal performance of MLI is extremely sensitive to mechanical compression and edge effects and can easily decrease from one to two orders of magnitude from its ideal value even when the MLI is kept under high vacuum condition. The present thermal-insulation systems are designed to perform well under soft vacuum level, in particular the range of 1 to 10 torr. They are also designed with larger interlayer spacings to reduce vulnerability to compression (and consequent heat leak) caused by installation and use. The superiority of these systems is the

  9. Ductile-brittle transition in transverse isotropic fibrous networks

    Science.gov (United States)

    Luo, Guoquan; Shi, Liping; Li, Mingwei; Zhong, Yesheng; He, Xiaodong; Wang, Jiazhi

    2018-01-01

    Anisotropic fibrous networks, especially transverse isotropic fibrous networks, are widely used to model the microstructures of biological tissues, polymer gels, fibrous thermal insulations, and other fibrous materials. In this letter, we build a three-dimensional transverse isotropic fibrous network model and study its mechanical properties along the through-thickness direction. We propose a measurement of anisotropy for transverse isotropic fibrous networks and then study the influence of anisotropy on the networks' mechanical properties, including its elastic modulus, maximum elongation, and stress-strain curve, by means of finite-element simulation. We also study theoretically the influence of anisotropy on maximum elongation. We find that as the anisotropy of the networks becomes stronger, the elastic modulus decreases and the maximum elongation increases, indicating a transition in mechanical properties from brittle to ductile. We identify this transition as the "ductile-brittle transition." This transition can help guide the design and regulate the mechanical properties of a transverse isotropic fibrous network.

  10. Model-based analysis of thermal insulation coatings

    DEFF Research Database (Denmark)

    Kiil, Søren

    2014-01-01

    Thermal insulation properties of coatings based on selected functional filler materials are investigated. The underlying physics, thermal conductivity of a heterogeneous two-component coating, and porosity and thermal conductivity of hollow spheres (HS) are quantified and a mathematical model...... for a thermal insulation coating developed. Data from a previous experimental investigation with hollow glass sphere-based epoxy and acrylic coatings were used for model validation. Simulations of thermal conductivities were in good agreement with experimental data. Using the model, a parameter study was also...... conducted exploring the effects of the following parameters: pigment (hollow spheres) volume concentration (PVC), average sphere size or sphere size distribution, thermal conductivities of binder and sphere wall material, and sphere wall thickness. All the parameters affected the thermal conductivity...

  11. Comparative study of thermal insulation boards from leaf and bark ...

    African Journals Online (AJOL)

    The aim of this study was to compare the performance of insulation boards made from leave and bark fibres of Pilios tigma thonningii L.in terms of density, water absorption, apparent thermal conductivity, specific heat and thermal diffusivity. The leave and the bark fibres were prepared in form of squared boards of 200 mm x ...

  12. 24 CFR 3280.207 - Requirements for foam plastic thermal insulating materials.

    Science.gov (United States)

    2010-04-01

    ... mineral fiber insulation or an equivalent thermal barrier; or (3) The foam plastic insulating material has... thermal insulating materials. 3280.207 Section 3280.207 Housing and Urban Development Regulations Relating... SAFETY STANDARDS Fire Safety § 3280.207 Requirements for foam plastic thermal insulating materials. (a...

  13. Newly developed foam ceramic body shows promise as thermal insulation material at 3000 deg F

    Science.gov (United States)

    Blocker, E. W.; Paul, R. D.

    1967-01-01

    Optimized zirconia foam ceramic body shows promise for use as a thermal insulation material. The insulating media displays low density and thermal conductivity, good thermal shock resistance, high melting point, and mechanical strength.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-05

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

  15. Energy Consumption of Insulated Material Using Thermal Effect Analysis

    Directory of Open Access Journals (Sweden)

    Fadzil M. A.

    2017-01-01

    Full Text Available Wall is one of the structures elements that resist direct heat from the atmosphere. Modification on several structures is relevance to reduce filtrate thermal movement on wall. Insulation material seems to be suitable to be implemented since its purpose meets the heat resistance requirement. Insulation material applied as to generate positive impact in energy saving through reduction in total building energy consumption. Fiberglass is one of the insulation materials that can be used to insulate a space from heat and sound. Fiberglass is flammable insulation material with R Value rated of R-2.9 to R-3.8 which meets the requirement in minimizing heat transfer. Finite element software, ABAQUS v6.13 employed for analyze non insulated wall and other insulated wall with different wall thicknesses. The several calculations related to overall heat movement, total energy consumption per unit area of wall, life cycle cost analysis and determination of optimal insulation thickness is calculated due to show the potential of the implementation in minimize heat transfer and generate potential energy saving in building operation. It is hoped that the study can contribute to better understanding on the potential building wall retrofitting works in increasing building serviceability and creating potential benefits for building owner.

  16. Interior thermal insulation systems for historical building envelopes

    Science.gov (United States)

    Jerman, Miloš; Solař, Miloš; Černý, Robert

    2017-11-01

    The design specifics of interior thermal insulation systems applied for historical building envelopes are described. The vapor-tight systems and systems based on capillary thermal insulation materials are taken into account as two basic options differing in building-physical considerations. The possibilities of hygrothermal analysis of renovated historical envelopes including laboratory methods, computer simulation techniques, and in-situ tests are discussed. It is concluded that the application of computational models for hygrothermal assessment of interior thermal insulation systems should always be performed with a particular care. On one hand, they present a very effective tool for both service life assessment and possible planning of subsequent reconstructions. On the other, the hygrothermal analysis of any historical building can involve quite a few potential uncertainties which may affect negatively the accuracy of obtained results.

  17. High temperature insulation materials for reradiative thermal protection systems

    Science.gov (United States)

    Hughes, T. A.

    1972-01-01

    Results are presented of a two year program to evaluate packaged thermal insulations for use under a metallic radiative TPS of a shuttle orbiter vehicle. Evaluations demonstrated their survival for up to 100 mission reuse cycles under shuttle acoustic and thermal loads with peak temperatures of 1000 F, 1800 F, 2000 F, 2200 F and 2500 F. The specimens were composed of low density refractory fiber felts, packaged in thin gage metal foils. In addition, studies were conducted on the venting requirements of the packages, salt spray resistance of the metal foils, and the thermal conductivity of many of the insulations as a function of temperature and ambient air pressure. Data is also presented on the radiant energy transport through insulations, and back-scattering coefficients were experimentally determined as a function of source temperature.

  18. Prediction of the Effective Thermal Conductivity of Powder Insulation

    Science.gov (United States)

    Jin, Lingxue; Park, Jiho; Lee, Cheonkyu; Jeong, Sangkwon

    The powder insulation method is widely used in structural and cryogenic systems such as transportation and storage tanks of cryogenic fluids. The powder insulation layer is constructed by small particle powder with light weight and some residual gas with high porosity. So far, many experiments have been carried out to test the thermal performance of various kinds of powder, including expanded perlite, glass microspheres, expanded polystyrene (EPS). However, it is still difficult to predict the thermal performance of powder insulation by calculation due to the complicated geometries, including various particle shapes, wide powder diameter distribution, and various pore sizes. In this paper, the effective thermal conductivity of powder insulation has been predicted based on an effective thermal conductivity calculationmodel of porous packed beds. The calculation methodology was applied to the insulation system with expanded perlite, glass microspheres and EPS beads at cryogenic temperature and various vacuum pressures. The calculation results were compared with previous experimental data. Moreover, additional tests were carried out at cryogenic temperature in this research. The fitting equations of the deformation factor of the area-contact model are presented for various powders. The calculation results show agood agreement with the experimental results.

  19. Estimating Clothing Thermal Insulation Using an Infrared Camera

    Science.gov (United States)

    Lee, Jeong-Hoon; Kim, Young-Keun; Kim, Kyung-Soo; Kim, Soohyun

    2016-01-01

    In this paper, a novel algorithm for estimating clothing insulation is proposed to assess thermal comfort, based on the non-contact and real-time measurements of the face and clothing temperatures by an infrared camera. The proposed method can accurately measure the clothing insulation of various garments under different clothing fit and sitting postures. The proposed estimation method is investigated to be effective to measure its clothing insulation significantly in different seasonal clothing conditions using a paired t-test in 99% confidence interval. Temperatures simulated with the proposed estimated insulation value show closer to the values of actual temperature than those with individual clothing insulation values. Upper clothing’s temperature is more accurate within 3% error and lower clothing’s temperature is more accurate by 3.7%~6.2% error in indoor working scenarios. The proposed algorithm can reflect the effect of air layer which makes insulation different in the calculation to estimate clothing insulation using the temperature of the face and clothing. In future, the proposed method is expected to be applied to evaluate the customized passenger comfort effectively. PMID:27005625

  20. Environmental impact of thermal insulations: How do natural insulation products differ from synthetic ones?

    Science.gov (United States)

    Dovjak, M.; Košir, M.; Pajek, L.; Iglič, N.; Božiček, D.; Kunič, R.

    2017-10-01

    As the environmental awareness of the public is rising and at the same time contemporary buildings are becoming more and more energy efficient, the focus is shifting towards the usage of environmentally friendly building products. Human decisions are often driven by emotions and perceptions. Consequently, there exists a strong tendency towards preferring “natural” constructional products to the synthetic ones, especially in the case of thermal insulations. Life cycle assessment (LCA) has enabled an opportunity to widen the meaning of the word “environmentally friendly”, giving researchers and building designers an objective decision making tool to determine the environmental impact of building products, building components and buildings as a whole. The purpose of this study was to compare the environmental impact of various thermal insulations for the cradle to gate life cycle stages, based on a unified functional unit. Overall, 15 most commonly used thermal insulation products were analysed and classified into natural and synthetic groups. Based on the differentiation, we compared the impact in the selected environmental categories and identified the most influential environmental drivers. The results show that in some environmental categoriesnatural thermal insulations perform better (i.e. global warming potential), whilein others (i.e. eutrophication potential) they underperform. However, environmental impact trends can be identified, specifically for the natural and the synthetic materials.

  1. Air-Filled Nanopore Based High-Performance Thermal Insulation Materials

    OpenAIRE

    Gangåssæter, Haakon Fossen; Jelle, Bjørn Petter; Alex Mofid, Sohrab; Gao, Tao

    2017-01-01

    State-of-the-art thermal insulation solutions like vacuum insulation panels (VIP) and aerogels have low thermal conductivity, but their drawbacks may make them unable to be the thermal insulation solutions that will revolutionize the building industry regarding energy-efficient building envelopes. Nevertheless, learning from these materials may be crucial to make new and novel high-performance thermal insulation products. This study presents a review on the state-of-the-art air-filled thermal...

  2. Electrically and Thermally Insulated Joint for Liquid Nitrogen Transfer

    DEFF Research Database (Denmark)

    Rasmussen, Carsten; Jensen, Kim Høj; Holbøll, Joachim T.

    1999-01-01

    A prototype of a superconducting cable is currently under construction. The cable conductor is cooled by liquid nitrogen in order to obtain superconductivity. The peripheral cooling circuit is kept at ground potential. This requires a joint which insulates both electrically and thermally...

  3. Parametric fuselage design : Integration of mechanics and acoustic & thermal insulation

    NARCIS (Netherlands)

    Krakers, L.A.

    2009-01-01

    Designing a fuselage is a very complex process, which involves many different aspects like strength and stability, fatigue, damage tolerance, fire resistance, thermal and acoustic insulation but also inspection, maintenance, production and repair aspects. It is difficult to include all design

  4. The Improvement of Thermal Insulating Concrete Panel

    Directory of Open Access Journals (Sweden)

    Mohammed Ali Nasser Ali

    2018-05-01

    Full Text Available The Iraqi houses flattening the roof by a concrete panel, and because of the panels on the top directly exposed to the solar radiation become unbearably hot and cold during the summer and winter. The traditional concrete panel components are cement, sand, and aggregate, which have a poor thermal property. The usage of materials with low thermal conductivity with no negative reflects on its mechanical properties gives good improvements to the thermal properties of the concrete panel. The practical part of this work was built on a multi-stage mixing plan. In the first stage the mixing ratio based on the ratios of the sand to cement. The second stage mixing ratios based on replacing the coarse aggregate quantities with the Alabaster aggregates, and the third stage the mixing ratios based on the replacement of wood ash instead of the sand. While the fourth stage mixing ratios based on decreasing the thermal conductivity and increasing mechanical properties by adding a multilayer of a plastic net. The result shows that using a concrete panel with components (cement, sand, coarse aggregate, wood ash, and Alabaster aggregates with a mass ratio of (1:1:2:1:1 and 3-plastic layers, gives the best improvement of the thermal properties. Where, the thermal conductivity is reduced by 42% and the specific heat increased by 41.2% as compared to the traditional concrete panel mixing ratio, with mechanical properties are agreed with the Iraqi standards.

  5. Wood moisture monitoring during log house thermal insulation mounting

    Directory of Open Access Journals (Sweden)

    Pavla Kotásková

    2011-01-01

    Full Text Available The current designs of thermal insulation for buildings concentrate on the achievement of the required heat transmission coefficient. However, another factor that cannot be neglected is the assessment of the possible water vapour condensation inside the construction. The aim of the study was to find out whether the designed modification of the cladding structure of an existing log house will or will not lead to a risk of possible water vapour condensation in the walls after an additional thermal insulation mounting. The condensation could result in the increase in moisture of the walls and consequently the constructional timber, which would lead to the reduction of the timber construction strength, wood degradation by biotic factors – wood-destroying insects, mildew or wood-destroying fungi. The main task was to compare the theoretically established values of moisture of the constructional timber with the values measured inside the construction using a specific example of a thermal insulated log house. Three versions of thermal insulation were explored to find the solution of a log house reconstruction which would be the optimum for living purposes. Two versions deal with the cladding structure with the insulation from the interior, the third version deals with an external insulation.In a calculation model the results can be affected to a great degree by input values (boundary conditions. This especially concerns the factor of vapour barrier diffusion resistance, which is entered in accordance with the producer’s specifications; however, its real value can be lower as it depends on the perfectness and correctness of the technological procedure. That is why the study also includes thermal technical calculations of all designed insulation versions in the most unfavourable situation, which includes the degradation of the vapour barrier down to 10% efficiency, i.e. the reduction of the diffusion resistance factor to 10% of the original value

  6. Influence of PCMs in thermal insulation on thermal behaviour of building envelopes

    Science.gov (United States)

    Dydek, K.; Furmański, P.; Łapka, P.

    2016-09-01

    A model of heat transfer through a wall consisting of a layer of concrete and PCM enhanced thermal insulation is considered. The model accounts for heat conduction in both layers, thermal radiation and heat absorption/release due to phase change in the insulation as well as time variation in the ambient temperature and insolation. Local thermal equilibrium between encapsulated PCM and light-weight thermal insulation was assumed. Radiation emission, absorption and scattering were also accounted for in the model. Comparison of different cases of heat flow through the building envelope was carried out. These cases included presence or absence of PCM and thermal radiation in the insulation, effect of emissivity of the PCM microcapsules as well as an effect of solar radiation or its lack on the ambient side of the envelope. Two ways of the PCM distribution in thermal insulation were also considered. The results of simulations were presented for conditions corresponding to the mean summer and winter seasons in Warsaw. It was found that thermal radiation plays an important role in heat transfer through thermal insulation layer of the wall while the presence of the PCM in it significantly contributes to damping of temperature fluctuations and a decrease in heat fluxes flowing into or lost by the interior of the building. The similar effect was observed for a decrease in emissivity of the microcapsules containing PCM.

  7. The advantage of selection of mineral thermal insulation materials with the structural properties for thermal insulation in buildings

    Directory of Open Access Journals (Sweden)

    Janžekovič Ines M.

    2014-01-01

    Full Text Available The paper deals with the problem of energy efficiency in Serbia. It gives a general overview of the energy losses and focuses on energy losses in buildings, which is recognized as one of the most problematic sectors as the energy losses concerns. By the very fact there is a need for more efficient implementation of measures to reduce energy losses through education and increased awareness of citizens about the proper ways of performing thermal protection of buildings. The paper points out the problems that arise when selecting the inadequate solutions of performing thermal insulation of buildings and suggests some solutions for the proper selection of materials for thermal insulation and in setting the appropriate requirements for thermal envelope for buildings.

  8. Workshop on technical assessment of industrial thermal insulation materials: summary

    International Nuclear Information System (INIS)

    Peterson, S.

    1976-07-01

    Over 80 participants representing 50 organizations met to discuss the report, Industrial Thermal Insulation--An Assessment, ORNL/TM-5283. Presentations on the performance of available materials, economic considerations, and measurement problems were followed by discussion. A final wrap-up session concluded that the report was valuable in pointing the direction for needed effort in the area, confirmed the indicated actions needed to further industrial application of insulation, and called for future meetings to continue the dialogue between the various facets of the industry

  9. Ternary binder based plasters with improved thermal insulating ability

    Science.gov (United States)

    Čáchová, M.; Koňáková, D.; Vejmelková, E.; Vyšvařil, M.

    2017-10-01

    New kind of plasters with improved thermal insulating ability are presented in this article. Improvement was reached by utilization of lightweight expanded perlite with high porosity. The second used aggregate was silica sand. Regarding the binder, three kind were combined for the reason of better plaster performance. Pure lime, Portland cement and pozzolanic ceramic powder were employed. Basic physical properties and thermal characteristics were determined. The porosity of plasters reached desired higher value about 50% and the thermal conductivity in dry state was lower than 0.16 Wm‑1K‑1.

  10. Requirements for thermal insulation on prestressed concrete reactor vessels

    International Nuclear Information System (INIS)

    Neylan, A.J.; Wistrom, J.D.

    1979-01-01

    During the past decade, extensive design, construction, and operating experience on concrete pressure vessels for gas-cooled reactor applications has accumulated. Excellent experience has been obtained to date on the structural components (concrete, prestressing systems, liners, penetrations, and closures) and the thermal insulation. Three fundamentally different types of insulation systems have been employed to ensure the satisfactory performance of this component, which is critical to the overall success of the prestressed concrete reactor vessel (PCRV). Although general design criteria have been published, the requirements for design, materials, and construction are not rigorously addressed in any national or international code. With the more onerous design conditions being imposed by advanced reactor systems, much greater attention has been directed to advance the state of the art of insulation systems for PCRVs. This paper addresses some of the more recent developments in this field being performed by General Atomic Company and others. (author)

  11. Technology of Double Thermal Insulation for the Repair and Energy Optimization of Existing Thermal Insulation Composite Systems

    Science.gov (United States)

    Belániová, Barbora; Antošová, Naďa

    2017-06-01

    The theme of improvement thermal proprieties of external cladding according to the New EU Directive is still a hot topic, which needs to be answered necessarily till December 2020. Maintenance and repair of existing ETICS became to also an actual open theme in search solutions for existing constructions. The aim of the research in this review is to analyze influence of layers the alternative thermal materials in technology "double thermal insulation". Humidity and temperature conditions will be further examined in connection with the development and colonization of microorganisms on surface construction.

  12. Dynamic Thermal Features of Insulated Blocks: Actual Behavior and Myths

    Directory of Open Access Journals (Sweden)

    Marta Cianfrini

    2017-11-01

    Full Text Available The latest updates in the European directive on energy performance of buildings have introduced the fundamental “nearly zero-energy building (NZEB” concept. Thus, a special focus needs to be addressed to the thermal performance of building envelopes, especially concerning the role played by thermal inertia in the energy requirements for cooling applications. In fact, a high thermal inertia of the outer walls results in a mitigation of the daily heat wave, which reduces the cooling peak load and the related energy demand. The common assumption that high mass means high thermal inertia typically leads to the use of high-mass blocks. Numerical and experimental studies on thermal inertia of hollow envelope components have not confirmed this general assumption, even though no systematic analysis is readily available in the open literature. Yet, the usually employed methods for the calculation of unsteady heat transfer through walls are based on the hypothesis that such walls are composed of homogeneous layers. In this framework, a study of the dynamic thermal performance of insulated blocks is brought forth in the present paper. A finite-volume method is used to solve the two-dimensional equation of conduction heat transfer, using a triangular-pulse temperature excitation to analyze the heat flux response. The effects of both the type of clay and the insulating filler are investigated and discussed at length. The results obtained show that the wall front mass is not the basic independent variable, since clay and insulating filler thermal diffusivities are more important controlling parameters.

  13. Quantitative analysis of silica aerogel-based thermal insulation coatings

    DEFF Research Database (Denmark)

    Kiil, Søren

    2015-01-01

    A mathematical heat transfer model for a silica aerogel-based thermal insulation coating was developed. The model can estimate the thermal conductivity of a two-component (binder-aerogel) coating with potential binder intrusion into the nano-porous aerogel structure. The latter is modelled using...... a so-called core–shell structure representation. Data from several previous experimental investigations with silica aerogels in various binder matrices were used for model validation. For some relevant cases with binder intrusion, it was possible to obtain a very good agreement between simulations...... containing intact hollow glass or polymer spheres showed that silica aerogel particles are more efficient in an insulation coating than hollow spheres. In a practical (non-ideal) comparison, the ranking most likely cannot be generalized. A parameter study demonstrates how the model can be used, qualitatively...

  14. Comparative study of hygrothermal properties of five thermal insulation materials

    OpenAIRE

    Laure Ducoulombier; Zoubeir Lafhaj

    2017-01-01

    The objective of this article is to carry out a comparative study of the main hygrothermal properties of five thermal insulation materials for buildings. These properties are necessary for a correct prediction of heat and moisture transfers through the walls and the selection of the most appropriate materials according to the specific buildings. The studied materials were glass wool, rock wool, expanded polystyrene, wood fiberboard and polyester fiberfill. The article is divided into three pa...

  15. Study of multilayered insulation pipe penetration. Thermal acoustic oscillation

    Science.gov (United States)

    Lovin, J. K.

    1974-01-01

    Tests were conducted to determine the net heat leak to a source of liquid nitrogen caused by a metal penetration through the blanket of multilayer insulation. The conditions under which the tests were conducted are described. A graph of the theoretical and experimental temperature distribution is developed for comparison. The variables involved in the computer program to process the data are defined. A study was conducted to develop analytical methods for predicting the effect and magnitudes of thermoacoustic oscillations on the penetration heat leak to cryogens. The oscillations develop as a result of large thermal gradients imposed on a compressible fluid. The predominant amplitudes and frequencies of the thermal acoustic oscillations were investigated.

  16. Thermal resistances of air in cavity walls and their effect upon the thermal insulation performance

    Energy Technology Data Exchange (ETDEWEB)

    Bekkouche, S.M.A.; Cherier, M.K.; Hamdani, M.; Benamrane, N. [Application of Renewable Energies in Arid and Semi Arid Environments /Applied Research Unit on Renewable Energies/ EPST Development Center of Renewable Energies, URAER and B.P. 88, ZI, Gart Taam Ghardaia (Algeria); Benouaz, T. [University of Tlemcen, BP. 119, Tlemcen R.p. 13000 (Algeria); Yaiche, M.R. [Development Center of Renewable Energies, CDER and B.P 62, 16340, Route de l' Observatoire, Bouzareah, Algiers (Algeria)

    2013-07-01

    The optimum thickness in cavity walls in buildings is determined under steady conditions; the heat transfer has been calculated according to ISO 15099:2003. Two forms of masonry units are investigated to conclude the advantage of high thermal emissivity. The paper presents also some results from a study of the thermal insulation performance of air cavities bounded by thin reflective material layer 'eta = 0.05'. The results show that the most economical cavity configuration depends on the thermal emissivity and the insulation material used.

  17. THERMAL INSULATION FROM LIGNIN-DERIVED CARBON FIBERS

    Energy Technology Data Exchange (ETDEWEB)

    Albers, Tracy [GrafTech International; Chen, Chong [GrafTech International; Eberle, Cliff [ORNL; Webb, Daniel C [ORNL

    2014-01-01

    Oak Ridge National Laboratory (ORNL) and GrafTech International Holdings Inc. (GrafTech) have collaborated to develop and demonstrate the performance of high temperature thermal insulation prototypes made from lignin-based carbon fibers (LBCF). This was the first reported production of LBCF or resulting products at scale > 1 kg. The results will potentially lead to the first commercial application of LBCF. The goal of the commercial application is to replace expensive, foreign-sourced isotropic pitch carbon fibers with lower cost carbon fibers made from a domestically sourced, bio-derived (renewable) feedstock. LBCF can help resolve supply chain vulnerability and reduce the production cost for high temperature thermal insulation as well as create US jobs. The performance of the LBCF prototypes was measured and found to be comparable to that of the current commercial product. During production of the insulation prototypes, the project team demonstrated lignin compounding/pelletization, fiber production, heat treatment, and compositing at scales far surpassing those previously demonstrated in LBCF R&D or production.

  18. Thermal Performance Evaluation of Walls with Gas Filled Panel Insulation

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Desjarlais, Andre Omer [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atchley, Jerald Allen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-11-01

    Gas filled insulation panels (GFP) are very light weight and compact (when uninflated) advanced insulation products. GFPs consist of multiple layers of thin, low emittance (low-e) metalized aluminum. When expanded, the internal, low-e aluminum layers form a honeycomb structure. These baffled polymer chambers are enveloped by a sealed barrier and filled with either air or a low-conductivity gas. The sealed exterior aluminum foil barrier films provide thermal resistance, flammability protection, and properties to contain air or a low conductivity inert gas. This product was initially developed with a grant from the U.S. Department of Energy. The unexpanded product is nearly flat for easy storage and transport. Therefore, transportation volume and weight of the GFP to fill unit volume of wall cavity is much smaller compared to that of other conventional insulation products. This feature makes this product appealing to use at Army Contingency Basing, when transportation cost is significant compared to the cost of materials. The objective of this study is to evaluate thermal performance of walls, similar to those used at typical Barracks Hut (B-Hut) hard shelters, when GFPs are used in the wall cavities. Oak Ridge National Laboratory (ORNL) tested performance of the wall in the rotatable guarded hotbox (RGHB) according to the ASTM C 1363 standard test method.

  19. Characterization of systems for external insulation and retrofitting with emphasis on the thermal performance

    DEFF Research Database (Denmark)

    Rudbeck, Claus; Rose, Jørgen

    1999-01-01

    to include the effect of thermal bridges by performing simple calculations, a task which normally requires the use of numerical models. The results show that thermal bridges in external insulation systems may decrease their thermal resistance by more than 25%.Key parameters was calculated by the use...... or unsatisfactory architectural look. One way of solving these problems is by adding a retrofitting system with thermal insulation to the existing building envelope. If external insulation systems are used, a new rain screen is applied on the outside of the insulation. Insulation can be applied either on the inside...... or the outside of the existing building envelope, but internal insulation has many disadvantages compared to external insulation. Several external insulation systems exist, each with different properties making it difficult for building designers to choose between systems in an objective manner.To help...

  20. Thermal insulating concrete wall panel design for sustainable built environment.

    Science.gov (United States)

    Zhou, Ao; Wong, Kwun-Wah; Lau, Denvid

    2014-01-01

    Air-conditioning system plays a significant role in providing users a thermally comfortable indoor environment, which is a necessity in modern buildings. In order to save the vast energy consumed by air-conditioning system, the building envelopes in envelope-load dominated buildings should be well designed such that the unwanted heat gain and loss with environment can be minimized. In this paper, a new design of concrete wall panel that enhances thermal insulation of buildings by adding a gypsum layer inside concrete is presented. Experiments have been conducted for monitoring the temperature variation in both proposed sandwich wall panel and conventional concrete wall panel under a heat radiation source. For further understanding the thermal effect of such sandwich wall panel design from building scale, two three-story building models adopting different wall panel designs are constructed for evaluating the temperature distribution of entire buildings using finite element method. Both the experimental and simulation results have shown that the gypsum layer improves the thermal insulation performance by retarding the heat transfer across the building envelopes.

  1. Low-Density, Aerogel-Filled Thermal-Insulation Tiles

    Science.gov (United States)

    Santos, Maryann; Heng, Vann; Barney, Andrea; Oka, Kris; Droege, Michael

    2005-01-01

    Aerogel fillings have been investigated in a continuing effort to develop low-density thermal-insulation tiles that, relative to prior such tiles, have greater dimensional stability (especially less shrinkage), equal or lower thermal conductivity, and greater strength and durability. In preparation for laboratory tests of dimensional and thermal stability, prototypes of aerogel-filled versions of recently developed low-density tiles have been fabricated by impregnating such tiles to various depths with aerogel formations ranging in density from 1.5 to 5.6 lb/ft3 (about 53 to 200 kg/cu m). Results available at the time of reporting the information for this article showed that the thermal-insulation properties of the partially or fully aerogel- impregnated tiles were equivalent or superior to those of the corresponding non-impregnated tiles and that the partially impregnated tiles exhibited minimal (tiles containing aerogels at the higher end of the density range are stable after multiple exposures at the said temperature.

  2. Thermal Insulating Concrete Wall Panel Design for Sustainable Built Environment

    Science.gov (United States)

    Zhou, Ao; Wong, Kwun-Wah

    2014-01-01

    Air-conditioning system plays a significant role in providing users a thermally comfortable indoor environment, which is a necessity in modern buildings. In order to save the vast energy consumed by air-conditioning system, the building envelopes in envelope-load dominated buildings should be well designed such that the unwanted heat gain and loss with environment can be minimized. In this paper, a new design of concrete wall panel that enhances thermal insulation of buildings by adding a gypsum layer inside concrete is presented. Experiments have been conducted for monitoring the temperature variation in both proposed sandwich wall panel and conventional concrete wall panel under a heat radiation source. For further understanding the thermal effect of such sandwich wall panel design from building scale, two three-story building models adopting different wall panel designs are constructed for evaluating the temperature distribution of entire buildings using finite element method. Both the experimental and simulation results have shown that the gypsum layer improves the thermal insulation performance by retarding the heat transfer across the building envelopes. PMID:25177718

  3. A Thermally Insulating Textile Inspired by Polar Bear Hair.

    Science.gov (United States)

    Cui, Ying; Gong, Huaxin; Wang, Yujie; Li, Dewen; Bai, Hao

    2018-04-01

    Animals living in the extremely cold environment, such as polar bears, have shown amazing capability to keep warm, benefiting from their hollow hairs. Mimicking such a strategy in synthetic fibers would stimulate smart textiles for efficient personal thermal management, which plays an important role in preventing heat loss and improving efficiency in house warming energy consumption. Here, a "freeze-spinning" technique is used to realize continuous and large-scale fabrication of fibers with aligned porous structure, mimicking polar bear hairs, which is difficult to achieve by other methods. A textile woven with such biomimetic fibers shows an excellent thermal insulation property as well as good breathability and wearability. In addition to passively insulating heat loss, the textile can also function as a wearable heater, when doped with electroheating materials such as carbon nanotubes, to induce fast thermal response and uniform electroheating while maintaining its soft and porous nature for comfortable wearing. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Radiation Abating Highly Flexible Multifunctional Polyimide Cryogenic and Thermal Insulation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The development of highly flexible thermal insulation materials with multifunctional properties based in polyimide polymers and designed to provide significant...

  5. Integrated MLI: Advanced Thermal Insulation Using Micro-Molding Technology, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Lightweight, high performance thermal insulation is critical to NASA's next generation Exploration spacecraft. Zero or low cryogenic propellant boiloff is required...

  6. Thermal insulation. Non-utilized energy need not be generated. Four rules for a successful thermal insulation by means of building insulation; Waermedaemmung. Energie, die nicht gebraucht wird, muss man nicht erzeugen. Vier Regeln fuer erfolgreichen Waermeschutz durch Gebaeudedaemmung

    Energy Technology Data Exchange (ETDEWEB)

    Patschke, Markus [3E-Consult, Nordkirchen (Germany); Drewer, Arnold [IpeG-Institut, Paderborn (Germany)

    2011-07-15

    The heat supply of buildings causes nearly one third of the energy consumption of an industrialized country. In 2006, the climate-adjusted heat consumption of private households in Germany amounted nearly 600 billion kWh. This consumption caused more than 167 million tons of CO{sub 2}. Heat insulation measures in buildings are required for all heat-transferring enveloping surface. Under this aspect, the contribution under consideration reports on four fundamental rules for a cost-efficient building insulation: (a) Only heated rooms should be insulated thermally; (b) Location and thermal insulation of cavities; (c) Selection of a suitable insulating material; (d) Consideration of an economic sustainability.

  7. Thermal Performance of Cryogenic Multilayer Insulation at Various Layer Spacings

    Science.gov (United States)

    Johnson, Wesley Louis

    2010-01-01

    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 general understanding of the many variables that are associated with MLI. MLI has been shown to be a function of variables such as warm boundary temperature, the number of reflector layers, and the spacer material in between reflectors, the interstitial gas pressure and the interstitial gas. Since the conduction between reflectors increases with the thickness of the spacer material, yet the radiation heat transfer is inversely proportional to the number of layers, it stands to reason that the thermal performance of MLI is a function of the number of layers per thickness, or layer density. Empirical equations that were derived based on some of the early tests showed that the conduction term was proportional to the layer density to a power. This power depended on the material combination and was determined by empirical test data. Many authors have graphically shown such optimal layer density, but none have provided any data at such low densities, or any method of determining this density. Keller, Cunnington, and Glassford showed MLI thermal performance as a function of layer density of high layer densities, but they didn't show a minimal layer density or any data below the supposed optimal layer density. However, it was recently discovered that by manipulating the derived empirical equations and taking a derivative with respect to layer density yields a solution for on optimal layer density. Various manufacturers have begun manufacturing MLI at densities below the optimal density. They began this based on the theory that increasing the distance between layers lowered the conductive heat transfer and they had no limitations on volume. By modifying the circumference of these blankets, the layer density can easily be

  8. Clothing resultant thermal insulation determined on a movable thermal manikin. Part I: effects of wind and body movement on total insulation.

    Science.gov (United States)

    Lu, Yehu; Wang, Faming; Wan, Xianfu; Song, Guowen; Shi, Wen; Zhang, Chengjiao

    2015-10-01

    In this serial study, 486 thermal manikin tests were carried out to examine the effects of air velocity and walking speed on both total and local clothing thermal insulations. Seventeen clothing ensembles with different layers (i.e., one, two, or three layers) were selected for the study. Three different wind speeds (0.15, 1.55, 4.0 m/s) and three levels of walking speed (0, 0.75, 1.2 m/s) were chosen. Thus, there are totally nine different testing conditions. The clothing total insulation and local clothing insulation at different body parts under those nine conditions were determined. In part I, empirical equations for estimating total resultant clothing insulation as a function of the static thermal insulation, relative air velocity, and walking speed were developed. In part II, the local thermal insulation of various garments was analyzed and correction equations on local resultant insulation for each body part were developed. This study provides critical database for potential applications in thermal comfort study, modeling of human thermal strain, and functional clothing design and engineering.

  9. APPRAISAL OF ECONOMICAL EFFICIENCY OF APPLICATION OF FIBROUS LINING IN THERMAL GASPLASMA FURNACES AND FURNACES OF RESISTANCE OF MACHINE-BUILDING PRODUCTION

    Directory of Open Access Journals (Sweden)

    V. I. Timoshpolskij

    2011-01-01

    Full Text Available The carried out calculations showed that partial modernization of thermal furnaces of machine building production by means of replacement of chamotte by fibrous fettling is economically reasonable and has rather short period of payback.

  10. Thermal-performance study of liquid metal fast breeder reactor insulation

    International Nuclear Information System (INIS)

    Shiu, K.K.

    1980-09-01

    Three types of metallic thermal insulation were investigated analytically and experimentally: multilayer reflective plates, multilayer honeycomb composite, and multilayer screens. Each type was subjected to evacuated and nonevacuated conditions, where thermal measurements were made to determine thermal-physical characteristics. A variation of the separation distance between adjacent reflective plates of multilayer reflective plates and multilayer screen insulation was also experimentally studied to reveal its significance. One configuration of the multilayer screen insulation was further selected to be examined in sodium and sodium oxide environments. The emissivity of Type 304 stainless steel used in comprising the insulation was measured by employing infrared technology. A comprehensive model was developed to describe the different proposed types of thermal insulation. Various modes of heat transfer inherent in each type of insulation were addressed and their relative importance compared. Provision was also made in the model to allow accurate simulation of possible sodium and sodium oxide contamination of the insulation. The thermal-radiation contribution to heat transfer in the temperature range of interest for LMFBR's was found to be moderate, and the suppression of natural convection within the insulation was vital in preserving its insulating properties. Experimental data were compared with the model and other published results. Moreover, the three proposed test samples were assessed and compared under various conditions as viable LMFBR thermal insulations

  11. Thermal-performance study of liquid metal fast breeder reactor insulation

    Energy Technology Data Exchange (ETDEWEB)

    Shiu, Kelvin K.

    1980-09-01

    Three types of metallic thermal insulation were investigated analytically and experimentally: multilayer reflective plates, multilayer honeycomb composite, and multilayer screens. Each type was subjected to evacuated and nonevacuated conditions, where thermal measurements were made to determine thermal-physical characteristics. A variation of the separation distance between adjacent reflective plates of multilayer reflective plates and multilayer screen insulation was also experimentally studied to reveal its significance. One configuration of the multilayer screen insulation was further selected to be examined in sodium and sodium oxide environments. The emissivity of Type 304 stainless steel used in comprising the insulation was measured by employing infrared technology. A comprehensive model was developed to describe the different proposed types of thermal insulation. Various modes of heat transfer inherent in each type of insulation were addressed and their relative importance compared. Provision was also made in the model to allow accurate simulation of possible sodium and sodium oxide contamination of the insulation. The thermal-radiation contribution to heat transfer in the temperature range of interest for LMFBR's was found to be moderate, and the suppression of natural convection within the insulation was vital in preserving its insulating properties. Experimental data were compared with the model and other published results. Moreover, the three proposed test samples were assessed and compared under various conditions as viable LMFBR thermal insulations.

  12. Experimental evaluation of outer planets probe thermal insulation concepts

    Science.gov (United States)

    Grote, M. G.; Mezines, S. A.

    1976-01-01

    An experimental program was conducted to evaluate various thermal insulation concepts for use in the Outer Planets Probe (OPP) during entry and descent into the atmospheres of Jupiter, Saturn, and Uranus. Phenolic fiberglass honeycomb specimens representative of the OPP structure were packed and tested with various fillers: Thermal conductivity measurements were made over a temperature range of 300 K to 483 K and pressures from vacuum up to 10 atmospheres in helium and nitrogen gas environments. The conductivity results could not be fully explained so new test specimens were designed with improved venting characteristics, and tested to determine the validity of the original data. All of the conductivity data showed results that were substantially higher than expected. The original test data in helium were lower than the data from the redesigned specimens, probably due to inadequate venting of nitrogen gas from the original specimens. The thermal conductivity test results show only a marginal improvement in probe thermal protection performance for a filled honeycomb core compared to an unfilled core. In addition, flatwise tension tests showed a severe bond strength degradation due to the inclusion of either the powder or foam fillers. In view of these results, it is recommended that the baseline OPP design utilize an unfilled core.

  13. Standard Practice for Evaluating Thermal Insulation Materials for Use in Solar Collectors

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1994-01-01

    1.1 This practice sets forth a testing methodology for evaluating the properties of thermal insulation materials to be used in solar collectors with concentration ratios of less than 10. Tests are given herein to evaluate the pH, surface burning characteristics, moisture adsorption, water absorption, thermal resistance, linear shrinkage (or expansion), hot surface performance, and accelerated aging. This practice provides a test for surface burning characteristics but does not provide a methodology for determining combustibility performance of thermal insulation materials. 1.2 The tests shall apply to blanket, rigid board, loose-fill, and foam thermal insulation materials used in solar collectors. Other thermal insulation materials shall be tested in accordance with the provisions set forth herein and should not be excluded from consideration. 1.3 The assumption is made that elevated temperature, moisture, and applied stresses are the primary factors contributing to the degradation of thermal insulation mat...

  14. Rigid Polyurethane Foam Thermal Insulation Protected with Mineral Intumescent Mat

    Directory of Open Access Journals (Sweden)

    Kirpluks Mikelis

    2014-12-01

    Full Text Available One of the biggest disadvantages of rigid polyurethane (PU foams is its low thermal resistance, high flammability and high smoke production. Greatest advantage of this thermal insulation material is its low thermal conductivity (λ, which at 18-28 mW/(m•K is superior to other materials. To lower the flammability of PU foams, different flame retardants (FR are used. Usually, industrially viable are halogenated liquid FRs but recent trends in EU regulations show that they are not desirable any more. Main concern is toxicity of smoke and health hazard form volatiles in PU foam materials. Development of intumescent passive fire protection for foam materials would answer problems with flammability without using halogenated FRs. It is possible to add expandable graphite (EG into PU foam structure but this increases the thermal conductivity greatly. Thus, the main advantage of PU foam is lost. To decrease the flammability of PU foams, three different contents 3%; 9% and 15% of EG were added to PU foam formulation. Sample with 15% of EG increased λ of PU foam from 24.0 to 30.0 mW/(m•K. This paper describes the study where PU foam developed from renewable resources is protected with thermally expandable intumescent mat from Technical Fibre Products Ltd. (TFP as an alternative to EG added into PU material. TFP produces range of mineral fibre mats with EG that produce passive fire barrier. Two type mats were used to develop sandwich-type PU foams. Also, synergy effect of non-halogenated FR, dimethyl propyl phosphate and EG was studied. Flammability of developed materials was assessed using Cone Calorimeter equipment. Density, thermal conductivity, compression strength and modulus of elasticity were tested for developed PU foams. PU foam morphology was assessed from scanning electron microscopy images.

  15. Apparatus for Testing Flat Specimens of Thermal Insulation

    Science.gov (United States)

    Fesmire, James E.; Augustynowicz, Stanislaw D.

    2005-01-01

    An apparatus has been developed to implement an improved method of testing flat-plate specimens of thermal-insulation materials for cryogenic application. The method includes testing under realistic use conditions that could include vacuum and mechanical loading at a pressure up to 70 psi (=0.48 MPa). The apparatus can accommodate a rigid or flexible specimen having thickness up to 1.25 in. (=3.2 cm) and diameters between 6 and 10 in. (about 15.2 and 25.4 cm, respectively). Typical test conditions include boundary temperatures between 77 K and 373 K and vacuum/interstitial gas filling at a pressure between 10(exp -6) torr (=1.3 x 10(exp -4) Pa) and 760 torr (atmospheric pressure =0.1 MPa). The interstitial gas could be N2, He, CO2, or any other suitable gas to which the insulation is expected to be exposed in use. Relative to prior apparatuses and testing methods, this apparatus and the testing method that it implements offer advantages of relative simplicity and ease of use. The basic principle of operation of the apparatus is that of boil-off calorimetry, using liquid nitrogen or any other suitable liquid that boils at a desired temperature below ambient temperature. Comparative rates of flow of heat through the thicknesses of the specimens (heat-leak rates) and apparent-thermal-conductivity values are obtained from tests of specimens. Absolute values of heat-leak rates and apparent thermal conductivities are computed from a combination of (1) the aforementioned comparative values and (2) calibration factors obtained by testing reference specimens of materials that have known thermal-insulation properties. The apparatus includes a full complement of temperature sensors, a vacuum pump and chamber, a monitoring and control system, and tools and fixtures that enable rapid and reliable installation and removal of specimens. A specimen is installed at the bottom of the vacuum chamber, and a cold-mass assembly that includes a tank is lowered into position above and

  16. Thermal mass vs. insulation building envelope design in six climatic regions of South Africa

    CSIR Research Space (South Africa)

    Kumirai, T

    2012-02-01

    Full Text Available This chapter aims to evaluate the impact of thermal mass and high insulation (Rvalue) building envelope on energy consumption (space heating and space cooling) in six South African major cities using a building thermal simulation programme (Ecotect...

  17. A thermal insulation system intended for a prestressed concrete vessel

    International Nuclear Information System (INIS)

    Aubert, Gilles; Petit, Guy.

    1975-01-01

    The description is given of a thermal insulation system withstanding the pressure of a vaporisable fluid for a prestressed concrete vessel, particularly the vessel of a boiling water nuclear reactor. The ring in the lower part of the vessel has, between the fluid inlet pipes and the bottom of the vessel, an annular opening of which the bottom edge is integral with an annular part rising inside the ring and parallel to it. This ring is hermetically connected to the bottom of the vessel and is coated with a metal lagging, at least facing the annular opening. This annular opening is made in the ring half-way up between the fluid inlet pipes and the bottom of the vessel. It is connected to the bottom of the vessel through the internal structure enveloping the reactor core [fr

  18. Hemp Thermal Insulation Concrete with Alternative Binders, Analysis of their Thermal and Mechanical Properties

    Science.gov (United States)

    Sinka, M.; Sahmenko, G.; Korjakins, A.; Radina, L.; Bajare, D.

    2015-11-01

    One of the main challenges that construction industry faces today is how to address the demands for more sustainable, environmentally friendly and carbon neutral construction materials and building upkeep processes. One of the answers to these demands is lime-hemp concrete (LHC) building materials - carbon negative materials that have sufficient thermal insulation capabilities to be used as thermal insulation materials for new as well as for existing buildings. But one problem needs to be overcome before these materials can be used on a large scale - current manufacturing technology allows these materials to be used only as self-bearing thermal insulation material with large labour intensity in the manufacturing process. In order to lower the labour intensity and allow the material to be used in wider applications, a LHC block and board production is necessary, which in turn calls for the binders different from the classically used ones, as they show insufficient mechanical strength for this new use. The particular study focuses on alternative binders produced using gypsum-cement compositions ensuring they are usable in outdoor applications together with hemp shives. Physical, mechanical, thermal and water absorption properties of hemp concrete with various binders are addressed in the current study.

  19. Thermal Insulation System for Non-Vacuum Applications Including a Multilayer Composite

    Science.gov (United States)

    Fesmire, James E. (Inventor)

    2017-01-01

    The thermal insulation system of the present invention is for non-vacuum applications and is specifically tailored to the ambient pressure environment with any level of humidity or moisture. The thermal insulation system includes a multilayered composite including i) at least one thermal insulation layer and at least one compressible barrier layer provided as alternating, successive layers, and ii) at least one reflective film provided on at least one surface of the thermal insulation layer and/or said compressible barrier layer. The different layers and materials and their combinations are designed to provide low effective thermal conductivity for the system by managing all modes of heat transfer. The thermal insulation system includes an optional outer casing surrounding the multilayered composite. The thermal insulation system is particularly suited for use in any sub-ambient temperature environment where moisture or its adverse effects are a concern. The thermal insulation system provides physical resilience against damaging mechanical effects including compression, flexure, impact, vibration, and thermal expansion/contraction.

  20. Anisotropic, lightweight, strong, and super thermally insulating nanowood with naturally aligned nanocellulose

    Science.gov (United States)

    Li, Tian; Song, Jianwei; Zhao, Xinpeng; Yang, Zhi; Pastel, Glenn; Xu, Shaomao; Jia, Chao; Dai, Jiaqi; Chen, Chaoji; Gong, Amy; Jiang, Feng; Yao, Yonggang; Fan, Tianzhu; Yang, Bao; Wågberg, Lars; Yang, Ronggui; Hu, Liangbing

    2018-01-01

    There has been a growing interest in thermal management materials due to the prevailing energy challenges and unfulfilled needs for thermal insulation applications. We demonstrate the exceptional thermal management capabilities of a large-scale, hierarchal alignment of cellulose nanofibrils directly fabricated from wood, hereafter referred to as nanowood. Nanowood exhibits anisotropic thermal properties with an extremely low thermal conductivity of 0.03 W/m·K in the transverse direction (perpendicular to the nanofibrils) and approximately two times higher thermal conductivity of 0.06 W/m·K in the axial direction due to the hierarchically aligned nanofibrils within the highly porous backbone. The anisotropy of the thermal conductivity enables efficient thermal dissipation along the axial direction, thereby preventing local overheating on the illuminated side while yielding improved thermal insulation along the backside that cannot be obtained with isotropic thermal insulators. The nanowood also shows a low emissivity of thermal energy. Moreover, the nanowood is lightweight yet strong, owing to the effective bonding between the aligned cellulose nanofibrils with a high compressive strength of 13 MPa in the axial direction and 20 MPa in the transverse direction at 75% strain, which exceeds other thermal insulation materials, such as silica and polymer aerogels, Styrofoam, and wool. The excellent thermal management, abundance, biodegradability, high mechanical strength, low mass density, and manufacturing scalability of the nanowood make this material highly attractive for practical thermal insulation applications. PMID:29536048

  1. Thermal properties of a sandwich construction insulated with Polyurethane (DC-System)

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund; Dreau, Jerome Le

    Rigid polyurethane foam (PUR) is a good thermal insulation product for buildings, mainly due to its low thermal conductivity (λ ≈ 20 mW/m.K), low permeability to water and stability over time. The other types of insulation products available on the market have a significantly higher thermal...... conductivity: + 50% for expanded polystyrene (λ ≈ 30 mW/m.K), + 75% for mineral wools (λ ≈ 35 mW/m.K), etc. Despite its low thermal conductivity, polyurethane foam (PUR) is not much used as insulation material for walls because of its low resistance to fire. The most common PUR boards are classified C-s2-d0...

  2. Polyimide-Foam/Aerogel Composites for Thermal Insulation

    Science.gov (United States)

    Williams, Martha; Fesmire, James; Sass, Jared; Smith, Trent; Weoser. Erol

    2009-01-01

    Composites of specific types of polymer foams and aerogel particles or blankets have been proposed to obtain thermal insulation performance superior to those of the neat polyimide foams. These composites have potential to also provide enhanced properties for vibration dampening or acoustic attenuation. The specific type of polymer foam is denoted "TEEK-H", signifying a series, denoted H, within a family of polyimide foams that were developed at NASA s Langley Research Center and are collectively denoted TEEK (an acronym of the inventors names). The specific types of aerogels include Nanogel aerogel particles from Cabot Corporation in Billerica, MA. and of Spaceloft aerogel blanket from Aspen Aerogels in Northborough, MA. The composites are inherently flame-retardant and exceptionally thermally stable. There are numerous potential uses for these composites, at temperatures from cryogenic to high temperatures, in diverse applications that include aerospace vehicles, aircraft, ocean vessels, buildings, and industrial process equipment. Some low-temperature applications, for example, include cryogenic storage and transfer or the transport of foods, medicines, and chemicals. Because of thermal cycling, aging, and weathering most polymer foams do not perform well at cryogenic temperatures and will undergo further cracking over time. The TEEK polyimides are among the few exceptions to this pattern, and the proposed composites are intended to have all the desirable properties of TEEK-H foams, plus improved thermal performance along with enhanced vibration or acoustic-attenuation performance. A composite panel as proposed would be fabricated by adding an appropriate amount of TEEK friable balloons into a mold to form a bottom layer. A piece of flexible aerogel blanket material, cut to the desired size and shape, would then be placed on the bottom TEEK layer and sandwiched between another top layer of polyimide friable balloons so that the aerogel blanket would become

  3. Investigation of potential waste material insulating properties at different temperature for thermal storage application

    Science.gov (United States)

    Ali, T. Z. S.; Rosli, A. B.; Gan, L. M.; Billy, A. S.; Farid, Z.

    2013-12-01

    Thermal energy storage system (TES) is developed to extend the operation of power generation. TES system is a key component in a solar energy power generation plant, but the main issue in designing the TES system is its thermal capacity of storage materials, e.g. insulator. This study is focusing on the potential waste material acts as an insulator for thermal energy storage applications. As the insulator is used to absorb heat, it is needed to find suitable material for energy conversion and at the same time reduce the waste generation. Thus, a small-scale experimental testing of natural cooling process of an insulated tank within a confined room is conducted. The experiment is repeated by changing the insulator from the potential waste material and also by changing the heat transfer fluid (HTF). The analysis presented the relationship between heat loss and the reserved period by the insulator. The results show the percentage of period of the insulated tank withstands compared to tank insulated by foam, e.g. newspaper reserved the period of 84.6% as much as foam insulated tank to withstand the heat transfer of cooking oil to the surrounding. The paper finally justifies the most potential waste material as an insulator for different temperature range of heat transfer fluid.

  4. Thermal spray coating for corrosion under insulation (CUI) prevention

    Science.gov (United States)

    Fuad, Mohd Fazril Irfan Ahmad; Razak, Khalil Abdul; Alias, Nur Hashimah; Othman, Nur Hidayati; Lah, Nik Khairul Irfan Nik Ab

    2017-12-01

    Corrosion under insulation (CUI) is one of the predominant issues affecting process of Oil and Gas and Petrochemical industries. CUI refers to external corrosion, but it is difficult to be detected as the insulation cover masks the corrosion problem. One of the options to prevent CUI is by utilizing the protective coating systems. Thermal spray coating (TSC) is an advanced coating system and it shows promising performance in harsh environment, which could be used to prevent CUI. However, the application of TSC is not attractive due to the high initial cost. This work evaluates the potential of TSC based on corrosion performance using linear polarization resistance (LPR) method and salt spray test (SST). Prior to the evaluation, the mechanical performance of TSC was first investigated using adhesion test and bend test. Microstructure characterization of the coating was investigated using Scanning Electron Microscope (SEM). The LPR test results showed that low corrosion rate of 0.05 mm/years was obtained for TSC in compared to the bare steel especially at high temperature of 80 °C, where usually normal coating would fail. For the salt spray test, there was no sign of corrosion products especially at the center (fully coated region) was observed. From SEM images, no corrosion defects were observed after 336 hours of continuous exposure to salt fog test. This indicates that TSC protected the steel satisfactorily by acting as a barrier from a corrosive environment. In conclusion, TSC can be a possible solution to minimize the CUI in a long term. Further research should be done on corrosion performance and life cycle cost by comparing TSC with other conventional coating technology.

  5. Clothing resultant thermal insulation determined on a movable thermal manikin. Part II: effects of wind and body movement on local insulation.

    Science.gov (United States)

    Lu, Yehu; Wang, Faming; Wan, Xianfu; Song, Guowen; Zhang, Chengjiao; Shi, Wen

    2015-10-01

    Part II of this two-part series study was focused on examining the effects of wind and body movement on local clothing thermal insulation. Seventeen clothing ensembles with different layers (i.e., 1, 2, or 3 layers) were selected for this study. Local thermal insulation with different air velocities (0.15, 1.55, and 4.0 m/s) and walking speeds (0, 0.75, and 1.17 m/s) were investigated on a thermal manikin. Empirical equations for estimating local resultant clothing insulation as a function of local insulation, air velocity, and walking speed were developed. The results showed that the effects of wind and body movement on local resultant thermal resistance are complex and differ distinctively among different body parts. In general, the reductions of local insulation with wind at the chest, abdomen, and pelvis were greater than those at the lower leg and back, and the changes at the body extremity such as the forearm, thigh, and lower leg were higher than such immobile body parts as the chest and back. In addition, the wind effect interacted with the walking effect. This study may have important applications in human local thermal comfort modeling and functional clothing design.

  6. Influence on Occupant Responses of Behavioral Modification of Clothing Insulation in Nonsteady Thermal Environments (RP-1269)

    DEFF Research Database (Denmark)

    Toftum, Jørn; Kolarik, Jakub; Belkowska, D.

    2010-01-01

    of the recommendations on drifting temperatures as stated in ASHRAE Standard 55-2004, Thermal Environmental Conditions for Human Occupancy (ASHRAE 2004) and to extend the scope of the recommendations to cover not only thermal comfort, but also the perception of air quality, health, and performance. The experiments....../h) condition when it was 2 h. Thermal sensation responses observed with adjustable clothing insulation did not differ from those observed with fixed clothing insulation, which were reported in an earlier paper. However, with fired clothing insulation, longer exposures (>4 h) seemed to aggravate general sick...

  7. Lighter touch keeps in the heat. [Advantages of low-thermal-mass insulation

    Energy Technology Data Exchange (ETDEWEB)

    Pipes, A.

    1979-04-01

    Low-thermal-mass insulation of ceramic fibers and light refractory materials is more suitable to applications with intermittent processes and lower-temperature melting and retreating, where the heat-retention requirements do not require traditional furnace design. Old furnaces can be retrofitted by replacing bricks with insulation or by veneering. Insulating materials include ceramic, alumina, and quartz fibers, and microtherm in the form of blocks, blankets and other shapes. 4 figures. (DCK)

  8. A lime based mortar for thermal insulation of medieval church vaults

    DEFF Research Database (Denmark)

    Hansen, Tessa Kvist; Larsen, Poul Klenz; Hansen, Kurt Kielsgaard

    There are 1700 medieval churches in Denmark, and many of these have brick vaults. The thickness is only 12 – 15 cm, and the heat loss through this building component is large. Thermal insulation has not been permitted until now in respect for the antiquarian values and doubts about the effect...... on water vapour transport through the vault, and the risk of condensation inside the insulation. A new mortar was developed for thermal insulation of bricks vaults, consisting mainly of expanded perlite, mixed with slaked lime. These materials are compatible with the fired clay bricks and the lime mortar...... joints. The insulation mortar is applied to the top side of the vault in a thickness of 10 cm, and covered by 10 mm lime plaster, reinforced with cattle hair. This assembly is resistant to the weight of a person, working with maintenance of the roof. The thermal conductivity of the insulation mortar...

  9. MODERN TECHNOLOGIES FOR APPLYING THE THERMAL INSULATIONS BASED ON CELLULOSE FLAKES

    Directory of Open Access Journals (Sweden)

    Daniela FIAT

    2013-05-01

    Full Text Available The paper presents cellulose thermal insulations based on cellulose flakes applied "in situ", by blowoutunder pressure. This mechanized method is using pneumatic systems with complex adjustments in order toobtain different densities and flow rates, when spraying the cellulose fibbers into the spaces to be insulated.

  10. Bionics in textiles: flexible and translucent thermal insulations for solar thermal applications.

    Science.gov (United States)

    Stegmaier, Thomas; Linke, Michael; Planck, Heinrich

    2009-05-13

    Solar thermal collectors used at present consist of rigid and heavy materials, which are the reasons for their immobility. Based on the solar function of polar bear fur and skin, new collector systems are in development, which are flexible and mobile. The developed transparent heat insulation material consists of a spacer textile based on translucent polymer fibres coated with transparent silicone rubber. For incident light of the visible spectrum the system is translucent, but impermeable for ultraviolet radiation. Owing to its structure it shows a reduced heat loss by convection. Heat loss by the emission of long-wave radiation can be prevented by a suitable low-emission coating. Suitable treatment of the silicone surface protects it against soiling. In combination with further insulation materials and flow systems, complete flexible solar collector systems are in development.

  11. Wrapped-IMLI: Thermal Insulation for Cryogenic Feed Lines, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA Exploration vehicles require improved technologies for passive thermal insulation for zero boil-off of cryopropellants during extended LEO and lunar surface...

  12. Heat gain from thermal radiation through protective clothing with different insulation, reflectivity and vapour permeability

    NARCIS (Netherlands)

    Bröde, P.; Kuklane, K.; Candas, V.; Hartog, E.A. den; Griefahn, B.; Holmér, I.; Meinander, H.; Nocker, W.; Richards, M.; Havenith, G.

    2010-01-01

    The heat transferred through protective clothing under long wave radiation compared to a reference condition without radiant stress was determined in thermal manikin experiments. The influence of clothing insulation and reflectivity, and the interaction with wind and wet underclothing were

  13. Absolute measurement of the thermal conductivity of insulating materials at high temperature

    International Nuclear Information System (INIS)

    Liermann, J.

    1975-01-01

    A device was developed at the CEA for the absolute measurement of the thermal conductivity of insulators. It can operate in controlled atmospheres (air, CO 2 , Ar, He) and between 100 and 1050 deg C [fr

  14. Effective Thermal Conductivity of High Temperature Insulations for Reusable Launch Vehicles

    Science.gov (United States)

    Daryabeigi, Kamran

    1999-01-01

    An experimental apparatus was designed to measure the effective thermal conductivity of various high temperature insulations subject to large temperature gradients representative of typical launch vehicle re-entry aerodynamic heating conditions. The insulation sample cold side was maintained around room temperature, while the hot side was heated to temperatures as high as 1800 degrees Fahrenheit. The environmental pressure was varied from 0.0001 to 760 torr. All the measurements were performed in a dry gaseous nitrogen environment. The effective thermal conductivity of Saffil, Q-Fiber felt, Cerachrome, and three multi-layer insulation configurations were measured.

  15. Characterization of an Integral Thermal Protection and Cryogenic Insulation Material for Advanced Space Transportation Vehicles

    Science.gov (United States)

    Salerno, L. J.; White, S. M.; Helvensteijn, B. P. M.

    2000-01-01

    NASA's planned advanced space transportation vehicles will benefit from the use of integral/conformal cryogenic propellant tanks which will reduce the launch weight and lower the earth-to-orbit costs considerably. To implement the novel concept of integral/conformal tanks requires developing an equally novel concept in thermal protection materials. Providing insulation against reentry heating and preserving propellant mass can no longer be considered separate problems to be handled by separate materials. A new family of materials, Superthermal Insulation (STI), has been conceiving and investigated by NASA's Ames Research Center to simultaneously provide both thermal protection and cryogenic insulation in a single, integral material.

  16. Thermal performance measurement and application of a multilayer insulator for emergency architecture

    International Nuclear Information System (INIS)

    Salvalai, Graziano; Imperadori, Marco; Scaccabarozzi, Diego; Pusceddu, Cristina

    2015-01-01

    Lightness coupled with a quick assembly method is crucial for emergency architecture in post-disaster area where accessibility and action time play a huge barer to rescue people. In this prospective, the following work analyses the potentiality (technological and thermal performances) of multilayer insulator for a new shelter envelope able to provide superior thermal comfort for the users. The thermal characteristics are derived experimentally by means of a guard ring apparatus under different working temperatures. Tests are performed on the multilayer insulator itself and on a composite structure, made of the multilayer insulator and two air gaps wrapped by a polyester cover, which is the core of a new lightweight emergency architecture. Experimental results show good agreement with literature data, providing a thermal conductivity and transmittance of about 0.04 W/(m °C) and 1.6 W/(m 2  °C) for the tested multilayer. The composite structure called Thermo Reflective Multilayer System (TRMS) shows better insulation performances, providing a thermal transmittance set to 0.85 W/(m 2  °C). A thermal model of an emergency tent based on the new insulating structure (TRMS) has been developed and its thermal performances have been compared with those of a UNHCR traditional emergency shelter. The shelter model was simulated (Trnsys v.17 environment) in the winter season considering the climate of Belgrade and using only the casual gains from occupant and solar radiation through opaque wall. Numerical simulations evidenced that the new insulating composite envelope reduces required heating load of about two and four times with respect to the traditional insulation. The study sets a starting point to develop a lightweight emergency architecture made with a combination between multilayer, air, polyester and vulcanized rubber. - Highlights: • Multilayer insulator tested by means of a guard ring apparatus. • Thermo reflective multilayer system (TRMS) development

  17. Thermo-Insulation Properties Of Hemp-Based Products

    Science.gov (United States)

    Lekavicius, V.; Shipkovs, P.; Ivanovs, S.; Rucins, A.

    2015-02-01

    As known, many multi-purpose plants can be used in different industries. This research is focused on the possibilities to utilize hemp as feedstock for thermal insulation products. The most advantageous features of hemp insulation are associated with health and environmental safety. The thermal conductivity of commercially available hemp insulation products is comparable with that of other fibrous insulation materials; however, it is possible to develop new products that could be more efficient in terms of cost and due to other important features.

  18. Thermo-Insulation Properties Of Hemp-Based Products

    Directory of Open Access Journals (Sweden)

    Lekavicius V.

    2015-02-01

    Full Text Available As known, many multi-purpose plants can be used in different industries. This research is focused on the possibilities to utilize hemp as feedstock for thermal insulation products. The most advantageous features of hemp insulation are associated with health and environmental safety. The thermal conductivity of commercially available hemp insulation products is comparable with that of other fibrous insulation materials; however, it is possible to develop new products that could be more efficient in terms of cost and due to other important features.

  19. Thermal Insulator for a Venus Lander, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A lander on the surface of Venus is heated by the 460 C surface temperature, which, even with the best current designs using passive insulation, cause its...

  20. Thermal characteristic of insulation for optimum design of RI transport package

    International Nuclear Information System (INIS)

    Lee, J. C.; Bang, K. S.; Seo, K. S.

    2002-01-01

    A package to transport the high level radioactive materials in required to withstand the hypothetical accident conditions as well as normal transport conditions according to IAEA and domestic regulations. The regulations require that the package should maintain the shielding, thermal and structural integrities to release no radioactive material. Thermal characteristics of insulations were evaluated and optimum insulation thickness was deduced for RI transport package. The package has a maximum capacity of 600 Curies for Ir-192 sealed source. The insulation thickness was decided with 10 mm of polyurethane form to maintain the thermal safety under fire accident condition. Thermal analysis was carried out for RI transport package, and it was shown that the thermal integrity of the package was maintained. The results obtained this study will be applied to a basic data for design of RI transport cask

  1. Partial Insulation of Aerated Concrete Wall in its Thermal Bridge Regions

    Science.gov (United States)

    Li, Baochang; Guo, Lirong; Li, Yubao; Zhang, Tiantian; Tan, Yufei

    2018-01-01

    As a self-insulating building material which can meet the 65 percent energy-efficiency requirements in cold region of China, aerated concrete blocks often go moldy, frost heaving, or cause plaster layer hollowing at thermal bridge parts in the extremely cold regions due to the restrictions of environmental climate and construction technique. In this paper, partial insulation measures of the thermal-bridge position of these parts of aerated concrete walls are designed to weaken or even eliminate thermal bridge effect and improve the temperature of thermal-bridge position. A heat transfer calculation model for L-shaped wall and T-shaped wall is developed. Based on the simulation result, the influence of the thickness on the temperature field is analyzed. Consequently, the condensation inside self-thermal-insulating wall and frost heaving caused by condensation and low temperature will be reduced, avoiding damage to the wall body from condensation..

  2. Thermophysical investigations of nanotechnological insulation materials

    Science.gov (United States)

    Lakatos, Ákos

    2017-07-01

    Nowadays, to sufficiently reduce the heat loss through the wall structures with the so-called traditional insulations (polystyrene and fibrous slabs), huge thicknesses (20 - 25 cm) must be applied. In some cases there is no place for their applications e.g.: historical or heritage builfings, since the use of nano-insulation materials (aerogel, vacuum ceramic paints) takes place. They are said to be much more efficient insulations than the above mentioned ones, since they should be used in thinner forms. In this article the thermal insulating capability of solid brick wall covered with a silica-aerogel slab with 1.3 cm, moreover with a vacuum ceramic hollow contained paint with 2 mm thick are investigated. As well as a literature review about the thermal conductivity of nano-technological insulation materials will be given. Comparison of the atomic and thermal diffusion will be also presented.

  3. A Facile Approach to Evaluate Thermal Insulation Performance of Paper Cups

    Directory of Open Access Journals (Sweden)

    Yudi Kuang

    2015-01-01

    Full Text Available Paper cups are ubiquitous in daily life for serving water, soup, coffee, tea, and milk due to their convenience, biodegradability, recyclability, and sustainability. The thermal insulation performance of paper cups is of significance because they are used to supply hot food or drinks. Using an effective thermal conductivity to accurately evaluate the thermal insulation performance of paper cups is complex due to the inclusion of complicated components and a multilayer structure. Moreover, an effective thermal conductivity is unsuitable for evaluating thermal insulation performance of paper cups in the case of fluctuating temperature. In this work, we propose a facile approach to precisely analyze the thermal insulation performance of paper cups in a particular range of temperature by using an evaluation model based on the MISO (Multiple-Input Single-Output technical theory, which includes a characterization parameter (temperature factor and a measurement apparatus. A series of experiments was conducted according to this evaluation model, and the results show that this evaluation model enables accurate characterization of the thermal insulation performance of paper cups and provides an efficient theoretical basis for selecting paper materials for paper cups.

  4. Evaluation of the thermal insulation of clothing of infants sleeping outdoors in Northern winter.

    Science.gov (United States)

    Tourula, Marjo; Fukazawa, Takako; Isola, Arja; Hassi, Juhani; Tochihara, Yutaka; Rintamäki, Hannu

    2011-04-01

    It is a common practice in Northern countries that children aged about 2 weeks to 2 years take their daytime sleep outdoors in prams in winter. The aim was to evaluate the thermal insulation of clothing of infants sleeping outdoors in winter. Clothing data of infants aged 3.5 months was collected, and sleep duration, skin and microclimate temperatures, humidity inside middle wear, air temperature and velocity of the outdoor environment were recorded during sleep taken outdoors (n = 34) and indoors (n = 33) in families' homes. The insulation of clothing ensembles was measured by using a baby-size thermal manikin, and the values were used for defining clothing insulation of the observed infants. Required clothing insulation for each condition was estimated according to ISO 11079. Clothing insulation did not correlate with ambient air temperature. The observed and required insulation of the study group was equal at about -5 °C, but overdressing existed in warmer and deficiency in thermal insulation in colder temperatures (r (s) 0.739, p < 0.001). However, even at -5 °C a slow cooling (ca. 0.012 °C/min) of mean skin temperature (T (sk)) was observed. When the difference between observed and required insulation increased, the cooling rate of T (sk) increased linearly (r (s) 0.605, p < 0.001) and the infants slept for a shorter period (r (s) 0.524, p = 0.001). The results of this study show the difficulty of adjusting systematically the optimal thermal insulation for outdoor sleeping infants during northern winter. Therefore, the necessity for guidelines is obvious. The study provides information for adequate cold protection of infants sleeping in cold conditions.

  5. Thermally Bonded PET–Basalt Sandwich Composites for Heat Pipeline Protection: Preparation, Stab Resisting, and Thermal-Insulating Properties

    Directory of Open Access Journals (Sweden)

    Ting-Ting Li

    2018-03-01

    Full Text Available In order to solve the cost and bulky problems of buried thermal pipeline insulating materials, this study adopts basalt fabric and low-melting PET nonwoven to construct low-cost and light-weight pipeline thermal-insulating composites after needle punching and thermal bonding processes. Research result shows that thermal-bonded temperature affected the stab resistance and burst energy more significantly. As thermal-bonded temperature increased, knife resistance and spike resistance presented the upward and then downward trends, but the burst energy gradually decreased. Yarn pull-out result shows that the enhancement of stab resistance of intra-/inter-thermal-bonded structure resulted from the increment in the coefficient of friction between yarns. When PET–basalt sandwich composites were thermal-bonded at 140 °C for 5 min, the maximum knife and spike resistance were 147.00 N (1.99 J and 196.30 N (1.11 J, respectively, and burst energy was 4.79 J, thermal conductivity reduced to 0.0073 W/(m∙K. The resultant thermally bonded sandwich composites can be used as thermal-insulating protection for buried thermal pipeline.

  6. The thermal insulation difference of clothing ensembles on the dry and perspiration manikins

    International Nuclear Information System (INIS)

    Xiaohong, Zhou; Chunqin, Zheng; Yingming, Qiang; Holmér, Ingvar; Gao, Chuansi; Kuklane, Kalev

    2010-01-01

    There are about a hundred manikin users around the world. Some of them use the manikin such as 'Walter' and 'Tore' to evaluate the comfort of clothing ensembles according to their thermal insulation and moisture resistance. A 'Walter' manikin is made of water and waterproof breathable fabric 'skin', which simulates the characteristics of human perspiration. So evaporation, condensation or sorption and desorption are always accompanied by heat transfer. A 'Tore' manikin only has dry heat exchange by conduction, radiation and convection from the manikin through clothing ensembles to environments. It is an ideal apparatus to measure the thermal insulation of the clothing ensemble and allows evaluation of thermal comfort. This paper compares thermal insulation measured with dry 'Tore' and sweating 'Walter' manikins. Clothing ensembles consisted of permeable and impermeable clothes. The results showed that the clothes covering the 'Walter' manikin absorbed the moisture evaporated from the manikin. When the moisture transferred through the permeable clothing ensembles, heat of condensation could be neglected. But it was observed that heavy condensation occurred if impermeable clothes were tested on the 'Walter' manikin. This resulted in a thermal insulation difference of clothing ensembles on the dry and perspiration manikins. The thermal insulation obtained from the 'Walter' manikin has to be modified when heavy condensation occurs. The modified equation is obtained in this study

  7. Thermal properties of a sandwich construction insulated with Polyurethane (DC-System)

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund; Dreau, Jerome Le

    Rigid polyurethane foam (PUR) is a good thermal insulation product for buildings, mainly due to its low thermal conductivity (λ ≈ 20 mW/m.K), low permeability to water and stability over time. The other types of insulation products available on the market have a significantly higher thermal condu...... resist to temperature as high as 800°C without major structural changes [3]. The challenge of this project consists in the association of the two materials. The study will be based both on numerical models and experimental tests (small and large scales)....

  8. An apparatus to measure the thermal conductivity of insulation panels at sub-ambient temperature

    NARCIS (Netherlands)

    Vanapalli, Srinivas; Klünder, T.; Hegeman, I.; Tolboom, A.H.; ter Brake, Hermanus J.M.

    2017-01-01

    A single-sided guarded-plate apparatus has been developed to measure the thermal conductivity of insulation panels of sub-meter size at sub-ambient temperatures ranging from 250 to 300 K. This apparatus allows thermal conductivity measurements to be performed at large temperature differences

  9. Foam/Aerogel Composite Materials for Thermal and Acoustic Insulation and Cryogen Storage

    Science.gov (United States)

    Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Weiser, Erik S. (Inventor); Sass, Jared P. (Inventor)

    2011-01-01

    The invention involves composite materials containing a polymer foam and an aerogel. The composite materials have improved thermal insulation ability, good acoustic insulation, and excellent physical mechanical properties. The composite materials can be used, for instance, for heat and acoustic insulation on aircraft, spacecraft, and maritime ships in place of currently used foam panels and other foam products. The materials of the invention can also be used in building construction with their combination of light weight, strength, elasticity, ability to be formed into desired shapes, and superior thermal and acoustic insulation power. The materials have also been found to have utility for storage of cryogens. A cryogenic liquid or gas, such as N.sub.2 or H.sub.2, adsorbs to the surfaces in aerogel particles. Thus, another embodiment of the invention provides a storage vessel for a cryogen.

  10. Effects of environmental exposure on cryogenic thermal insulation materials

    Science.gov (United States)

    Parmley, R. T.; Smith, F. J.; Glassford, A. P.; Coleman, J.; Stevenson, D. R.

    1973-01-01

    Investigation was made to optimize selection of insulation materials for reusable space vehicles which will be repeatedly operated over periods of up to ten years. Results of study are summarized in two reports. Volume I describes tests and significant findings. In Volume II, extensive test data obtained are organized in handbook form.

  11. Load Responsive MLI: Thermal Insulation with High In-Atmosphere and On-Orbit Performance, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Lightweight, high performance thermal insulation is critical to NASA's next generation Exploration spacecraft. Zero or low cryogenic propellant boiloff is required...

  12. Measuring Thermal Conductivity and Moisture Absorption of Cryo-Insulation Materials

    Science.gov (United States)

    Lambert, Michael A.

    1998-01-01

    NASA is seeking to develop thermal insulation material systems suitable for withstanding both extremely high temperatures encountered during atmospheric re-entry heating and aero- braking maneuvers, as well as extremely low temperatures existing in liquid fuel storage tanks. Currently, materials used for the high temperature insulation or Thermal Protection System (TPS) are different from the low temperature, or cryogenic insulation. Dual purpose materials are necessary to the development of reusable launch vehicles (RLV). The present Space Shuttle (or Space Transportation System, STS) employs TPS materials on the orbiter and cryo-insulation materials on the large fuel tank slung under the orbiter. The expensive fuel tank is jettisoned just before orbit is achieved and it burns up while re-entering over the Indian Ocean. A truly completely reusable launch vehicle must store aR cryogenic fuel internally. The fuel tanks will be located close to the outer surface. In fact the outer skin of the craft will probably also serve as the fuel tank enclosure, as in jet airliners. During a normal launch the combined TPS/cryo-insulation system will serve only as a low temperature insulator, since aerodynamic heating is relatively minimal during ascent to orbit. During re-entry, the combined TPS/cryo-insulation system will serve only as a high temperature insulator, since all the cryogenic fuel will have been expended in orbit. However, in the event of an.aborted launch or a forced/emergency early re-entry, the tanks will still contain fuel, and the TPS/cryo-insulation will have to serve as both low and high temperature insulation. Also, on long duration missions, such as to Mars, very effective cryo-insulation materials are needed to reduce bod off of liquid propellants, thereby reducing necessary tankage volume, weight, and cost. The conventional approach to obtaining both low and high temperature insulation, such as is employed for the X-33 and X-34 spacecraft, is to use

  13. Incorporation of Polymers into Calcined Clays as Improved Thermal Insulating Materials for Construction

    Directory of Open Access Journals (Sweden)

    Serina Ng

    2017-01-01

    Full Text Available Calcined clay is a Type Q supplementary cementing material according to EN197-1:2000. It possesses lower thermal conductivity than cement. To further improve its thermal insulation property, polymer-calcined clay complexes (PCCs were produced in a one-pot synthesis. Two contrasting polymers, polystyrene (PS and polyethylene glycol (PEG, were employed. The hydrophilicity of the polymers influenced the thermal conductivity of PCC. Hydrophilic PEG entrapped more water molecules on clay layers than the hydrophobic PS, making PEG-PCC more thermally conducting than PS-PCC. Contaminants in calcined clays played a role in affecting the overall thermal conductivity. PCC can improve thermal insulation properties for future construction applications.

  14. Incorporation of Polymers into Calcined Clays as Improved Thermal Insulating Materials for Construction

    OpenAIRE

    Ng, Serina; Jelle, Bjørn Petter

    2017-01-01

    Calcined clay is a Type Q supplementary cementing material according to EN197-1:2000. It possesses lower thermal conductivity than cement. To further improve its thermal insulation property, polymer-calcined clay complexes (PCCs) were produced in a one-pot synthesis. Two contrasting polymers, polystyrene (PS) and polyethylene glycol (PEG), were employed. The hydrophilicity of the polymers influenced the thermal conductivity of PCC. Hydrophilic PEG entrapped more water molecules on clay layers...

  15. The Modeling and Simulation of Thermal Analysis at Hydro Generator Stator Winding Insulation

    Directory of Open Access Journals (Sweden)

    Mihaela Raduca

    2006-10-01

    Full Text Available This paper presents the modelling and simulation of thermal analysis at hydro generator stator winding. The winding stator is supplied at high voltage of 11 kV for high power hydro generator. To present the thermal analysis for stator winding is presented at supply of coil by 11 kV, when coil is heat and thermal transfer in insulation at ambient temperature.

  16. Thermal paint production: the techno-economic evaluation of muscovite as insulating additive.

    Directory of Open Access Journals (Sweden)

    Gabriela Fernandes Ribas

    2016-09-01

    Full Text Available Muscovite is known by its thermal and electrical insulating properties. Based on this, it was hypothesized that its addition on paints should increase the thermal resistance. The use of muscovite as mineral insulating is pointed out as advantageous due to its low cost compared to other materials used for this purpose, such as the ceramic microsphere. The use of a low cost material could open the access to the medium and low income families, implying two aspects: the life quality increase by thermal comfort and the increase of energy saving. Thus, this part of the population could open a new market to thermal paints. Aiming to contribute to this issue, this work evaluated the thermal insulation performance of commercial paints containing muscovite additions and determined the economic evaluation for its industrial production. The thermal paint was formulated by adding 10%, 20% and 40% of muscovite to the commercial paint. This was applied on steel reinforced mortar boards. Thermal insulation tests were carried out in bench scale using an adapted box. The economic evaluation of the industrial production of muscovite-based thermal paint was conducted, considering the Brazilian economic market in this activity. The results showed its ability as an insulating agent due to a reduction of 0.667 °C/mm board by the addition of 40% muscovite. The economic analysis also demonstrated the feasibility of the thermal paint industrial production. The payback is favorable to 5 years when compared to the Selic short-term lending rate, with 21.53% of internal rate return and a net present value of US$ 15,085.76.

  17. Transient analysis and improvement of indoor thermal comfort for an air-conditioned room with thermal insulations

    Directory of Open Access Journals (Sweden)

    D. Prakash

    2015-09-01

    Full Text Available Thermal insulations over the building envelop reduce the heat gain due to solar radiation and may enhance good and uniform indoor thermal comfort for the occupants. In this paper, the insulation layer-wood wool is laid over the roof and exposed wall of an air-conditioned room and its performance on indoor thermal comfort is studied by computational fluid dynamics (CFD technique. From this study, 3% of indoor thermal comfort index-predicted mean vote (PMV is improved by providing wood wool layer. In addition, the optimum supply air temperature of air-conditioning unit for good thermal comfort is predicted as in the range of 299–300 K (26–27 °C.

  18. Effect of thermal-treatment sequence on sound absorbing and mechanical properties of porous sound-absorbing/thermal-insulating composites

    Directory of Open Access Journals (Sweden)

    Huang Chen-Hung

    2016-01-01

    Full Text Available Due to recent rapid commercial and industrial development, mechanical equipment is supplemented massively in the factory and thus mechanical operation causes noise which distresses living at home. In livelihood, neighborhood, transportation equipment, jobsite construction noises impact on quality of life not only factory noise. This study aims to preparation technique and property evaluation of porous sound-absorbing/thermal-insulating composites. Hollow three-dimensional crimp PET fibers blended with low-melting PET fibers were fabricated into hollow PET/low-melting PET nonwoven after opening, blending, carding, lapping and needle-bonding process. Then, hollow PET/low-melting PET nonwovens were laminated into sound-absorbing/thermal-insulating composites by changing sequence of needle-bonding and thermal-treatment. The optimal thermal-treated sequence was found by tensile strength, tearing strength, sound-absorbing coefficient and thermal conductivity coefficient tests of porous composites.

  19. Vacuum Insulation Panels: Analysis of the Thermal Performance of Both Single Panel and Multilayer Boards

    Directory of Open Access Journals (Sweden)

    Alfonso Capozzoli

    2015-03-01

    Full Text Available The requirements for improvement in the energy efficiency of buildings, mandatory in many EU countries, entail a high level of thermal insulation of the building envelope. In recent years, super-insulation materials with very low thermal conductivity have been developed. These materials provide satisfactory thermal insulation, but allow the total thickness of the envelope components to be kept below a certain thickness. Nevertheless, in order to penetrate the building construction market, some barriers have to be overcome. One of the main issues is that testing procedures and useful data that are able to give a reliable picture of their performance when applied to real buildings have to be provided. Vacuum Insulation Panels (VIPs are one of the most promising high performing technologies. The overall, effective, performance of a panel under actual working conditions is influenced by thermal bridging, due to the edge of the panel envelope and to the type of joint. In this paper, a study on the critical issues related to the laboratory measurement of the equivalent thermal conductivity of VIPs and their performance degradation due to vacuum loss has been carried out utilizing guarded heat flux meter apparatus. A numerical analysis has also been developed to study thermal bridging effect when VIP panels are adopted to create multilayer boards for building applications.

  20. Vulcanization Kinetics and Mechanical Properties of Ethylene Propylene Diene Monomer Thermal Insulation

    Directory of Open Access Journals (Sweden)

    Mohamad Irfan Fathurrohman

    2015-07-01

    Full Text Available The vulcanization kinetics of Ethylene-propylene diene monomer (EPDM rubber thermal insulation was studied by using rheometer under isothermal condition at different temperatures. The rheometry analysis was used to determining the cure kinetic parameters and predicting the cure time of EPDM thermal insulation. The experimental results revealed that the curing curves of EPDM thermal insulation were marching and the optimum curing time decreased with increasing the temperature. The kinetic parameters were determined from the autocatalytic model showed close fitting with the experimental results, indicating suitability of autocatalytic model in characterizing the cure kinetics. The activation energy was determined from the autocatalytic model is 46.3661 kJ mol-1. The cure time were predicted from autocatalytic model and the obtained kinetic parameter by using the relationship among degree of conversion, cure temperature, and cure time. The predictions of cure time provide information for the actual curing characteristic of EPDM thermal insulation. The mechanical properties of EPDM thermal insulation with different vulcanization temperatures showed the same hardness, tensile strength and modulus at 300%, except at temperature 70 °C, while the elongation at breaking point decreased with increasing temperature of vulcanization. © 2015 BCREC UNDIP. All rights reservedReceived: 8th April 2014; Revised: 7th January 2015; Accepted: 16th January 2015How to Cite: Fathurrohman, M.I., Maspanger, D.R., Sutrisno, S. (2015. Vulcanization Kinetics and Mechanical Properties of Ethylene Propylene Diene Monomer Thermal Insulation. Bulletin of Chemi-cal Reaction Engineering & Catalysis, 10 (2, 104-110. (doi:10.9767/bcrec.10.2.6682.104-110Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.2.6682.104-110 

  1. Multilevel radiative thermal memory realized by the hysteretic metal-insulator transition of vanadium dioxide

    International Nuclear Information System (INIS)

    Ito, Kota; Nishikawa, Kazutaka; Iizuka, Hideo

    2016-01-01

    Thermal information processing is attracting much interest as an analog of electronic computing. We experimentally demonstrated a radiative thermal memory utilizing a phase change material. The hysteretic metal-insulator transition of vanadium dioxide (VO 2 ) allows us to obtain a multilevel memory. We developed a Preisach model to explain the hysteretic radiative heat transfer between a VO 2 film and a fused quartz substrate. The transient response of our memory predicted by the Preisach model agrees well with the measured response. Our multilevel thermal memory paves the way for thermal information processing as well as contactless thermal management

  2. Assessment of Long Thermal Ageing on the Oil-Paper Insulation

    Directory of Open Access Journals (Sweden)

    Iraida Kolcunova

    2016-01-01

    Full Text Available Electric power equipment has complex construction. Therefore, it is very important to have enough information about the state of equipment. High voltage transformers play a very important role in the electric power system. One of the most important parts of electric power equipment is the insulation system. Insulation system must be in a good condition for reliable and safe operation of electrical devices. Insulation system of electrical equipment is exposed to various factors which could have negative influence on its condition. Oil impregnated insulation paper is one of the oldest insulation systems used in electrical power equipment. Mineral oils have been used for decades as transformer fluids because of their excellent dielectric properties and availability. However, performance of mineral oil starts to be limited due to environmental consideration. The aim of this paper is to simulate a real insulation system of transformer and to show the influence of accelerated thermal ageing on the insulation system. Properties such as relative permittivity, dissipation factor and the breakdown voltage will be described and analysed.

  3. Large Enhancement of Thermal Conductivity and Lorenz Number in Topological Insulator Thin Films.

    Science.gov (United States)

    Luo, Zhe; Tian, Jifa; Huang, Shouyuan; Srinivasan, Mithun; Maassen, Jesse; Chen, Yong P; Xu, Xianfan

    2018-02-27

    Topological insulators (TI) have attracted extensive research effort due to their insulating bulk states but conducting surface states. However, investigation and understanding of thermal transport in topological insulators, particularly the effect of surface states, are lacking. In this work, we studied thickness-dependent in-plane thermal and electrical conductivity of Bi 2 Te 2 Se TI thin films. A large enhancement in both thermal and electrical conductivity was observed for films with thicknesses below 20 nm, which is attributed to the surface states and bulk-insulating nature of these films. Moreover, a surface Lorenz number much larger than the Sommerfeld value was found. Systematic transport measurements indicated that the Fermi surface is located near the charge neutrality point (CNP) when the film thickness is below 20 nm. Possible reasons for the large Lorenz number include electrical and thermal current decoupling in the surface state Dirac fluid, and bipolar diffusion transport. A simple computational model indicates that the surface states and bipolar diffusion indeed can lead to enhanced electrical and thermal transport and a large Lorenz number.

  4. Correlation Function Approach for Estimating Thermal Conductivity in Highly Porous Fibrous Materials

    Science.gov (United States)

    Martinez-Garcia, Jorge; Braginsky, Leonid; Shklover, Valery; Lawson, John W.

    2011-01-01

    Heat transport in highly porous fiber networks is analyzed via two-point correlation functions. Fibers are assumed to be long and thin to allow a large number of crossing points per fiber. The network is characterized by three parameters: the fiber aspect ratio, the porosity and the anisotropy of the structure. We show that the effective thermal conductivity of the system can be estimated from knowledge of the porosity and the correlation lengths of the correlation functions obtained from a fiber structure image. As an application, the effects of the fiber aspect ratio and the network anisotropy on the thermal conductivity is studied.

  5. Reentry thermal protection from Pioneer F RTG insulation material

    Science.gov (United States)

    Vorreiter, J. W.

    1972-01-01

    Ablation tests were performed on the insulation material used in the Pioneer F radioisotope thermoelectric generator (RTG) in the Ames Arc-Heated Planetary-Gas Wind Tunnel. Test results indicate that the material, trade name Min-K 1301, should experience little ablation for heat transfer rates below 40 BTU/sq ft-sec. If the current design were to be changed so that the various pieces of Min-K were fastened or interlocked together the total amount of heat delivered to the RTG heat source during an earth orbital decay reentry would be reduced by at least 22.7%.

  6. Correlation between stabilizer consumption and degree of polymerization of thermally upgraded paper aged in insulating natural ester and insulating mineral oil

    Directory of Open Access Journals (Sweden)

    Larissa Mildemberger

    2016-02-01

    Full Text Available Abstract Insulating paper holds significant importance in the insulation system of power transformers, and thus, its degradation is the subject of many studies. A successful evaluation of the degradation rate of such paper contributes to reducing downtime and avoiding equipment failure. In this work, samples of thermally upgraded paper were thermally aged in insulating natural ester (INE and insulating mineral oil (IMO and were evaluated by degree of polymerization (DP and FTIR-ATR. It was possible to identify characteristic bands of dicyandiamide, an inhibitory compound of the thermal degradation of the paper, and to establish a correlation between the decrease in DP and the consumption of dicyandiamide during aging, which was observed to develop in three distinct steps for both IMO and INE.

  7. Design parameters for single pipe thermal insulation systems for offshore flow assurance

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Adam; Johnsen, Erik; Kopystynski, Adam; Simonsen, Eirik; Boye-Hansen, Allan [Bredero Shaw (Thermotite), Orkanger (Norway)

    2005-07-01

    Limit state design of subsea thermal insulation systems has been shown to be feasible and robust. This requires careful implementation of extensive long-term laboratory data and property models into verified FEA / FDA tools. Such simulations allow for the determination of not only the steady state response, but also the transient response of the system as a function of temperature, hydrostatic loading, ageing, water ingress and time. This departure from the traditional use of monolithic thermal conductivities, heat capacities and water absorption values can allow in some cases for a reduction in the thickness of insulation, whilst simultaneously enabling control of conservatism. The current paper discusses the important influences affecting the performance of insulant systems and the results of verification testing along with design examples where the generally accepted design method is compared to the limit state approach. (author)

  8. A Literature Review of Sealed and Insulated Attics—Thermal, Moisture and Energy Performance

    Energy Technology Data Exchange (ETDEWEB)

    Less, Brennan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Levinson, Ronnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-08-01

    In this literature review and analysis, we focus on the thermal, moisture and energy performance of sealed and insulated attics in California climates. Thermal. Sealed and insulated attics are expected to maintain attic air temperatures that are similar to those in the house within +/- 10°F. Thermal stress on the assembly, namely high shingle and sheathing temperatures, are of minimal concern. In the past, many sealed and insulated attics were constructed with insufficient insulation levels (~R-20) and with too much air leakage to outside, leading to poor thermal performance. To ensure high performance, sealed and insulated attics in new California homes should be insulated at levels at least equivalent to the flat ceiling requirements in the code, and attic envelopes and ducts should be airtight. We expect that duct systems in well-constructed sealed and insulated attics should have less than 2% HVAC system leakage to outside. Moisture. Moisture risk in sealed and insulated California attics will increase with colder climate regions and more humid outside air in marine zones. Risk is considered low in the hot-dry, highly populated regions of the state, where most new home construction occurs. Indoor humidity levels should be controlled by following code requirements for continuous whole-house ventilation and local exhaust. Pending development of further guidance, we recommend that the air impermeable insulation requirements of the International Residential Code (2012) be used, as they vary with IECC climate region and roof finish. Energy. Sealed and insulated attics provide energy benefits only if HVAC equipment is located in the attic volume, and the benefits depend strongly on the insulation and airtightness of the attic and ducts. Existing homes with leaky, uninsulated ducts in the attic should have major savings. When compared with modern, airtight duct systems in a vented attic, sealed and insulated attics in California may still provide substantial benefit

  9. Thermal Jacket Design Using Cellulose Aerogels for Heat Insulation Application of Water Bottles

    Directory of Open Access Journals (Sweden)

    Hai M. Duong

    2017-11-01

    Full Text Available Thermal jacket design using eco-friendly cellulose fibers from recycled paper waste is developed in this report. Neoprene as an outmost layer, cellulose aerogels in the middle and Nylon as an innermost layer can form the best sandwiched laminate using the zigzag stitching method for thermal jacket development. The temperature of the ice slurry inside the water bottle covered with the designed thermal jackets remains at 0.1 °C even after 4 h, which is the average duration of an outfield exercise. Interestingly, the insulation performance of the designed thermal jackets is much better than the commercial insulated water bottles like FLOE bottles and is very competition to that of vacuum flasks for a same period of 4 h and ambient conditions.

  10. A lime based mortar for thermal insulation of medieval church vaults

    DEFF Research Database (Denmark)

    Larsen, P.K.; Hansen, Tessa Kvist

    , and covered by 10 mm lime plaster, reinforced with cattle hair. This assembly can carry the weight of a person, working with maintenance of the roof. Climate measurements confirmed excellent properties in regards to both moisture transport and thermal insulation. Condensation did not occur at any time...

  11. Studies on a thermal insulation layer in the high pressure, high temperature gas, (1)

    International Nuclear Information System (INIS)

    Shimomura, Hiroaki

    1978-03-01

    Basic equations of heat transfer in a thermal insulation layers are presented in the high pressure, high temperature gas atmosphere. Natural convective heat transfer in the packed beds is then studied. Further described are experiments plans and principal particulars of experimental apparatus based on the above discussions. (auth.)

  12. Thermal noise in double injection diodes operating in the insulator regime

    NARCIS (Netherlands)

    Zijlstra, R.J.J.; Gisolf, A.

    Thermal noise calculations, based on the Langevin procedure, are given for a double injection diode operating in the insulator regime. The frequency range is restricted to frequencies smaller than the reciprocal free carrier transit times. It turns out that at high frequencies the spectral density

  13. Use of XPS thermal insulator boards in design of educational spaces

    African Journals Online (AJOL)

    Heating and cooling equipment capacity becomes smaller than half after proper implementation of thermal insulation. As air conditioning equipment becomes small, implementation of optimization not only becomes free but also reduces the overall cost of construction. Keywords: School, modern materials, Building and ...

  14. Development of Lightweight Calcium-Magnesium based Panels (LCMP) as a Thermal Insulation for Structures

    OpenAIRE

    Karimi, Amir Khosro

    2013-01-01

    Buildings are consumers of large amounts of energy in all countries. In regions with tough climate conditions, a good percentage of the total energy consumption is due to cooling and heating of the buildings. The most important factor of saving energy in buildings is to be aware of thermal properties of the construction materials. The correct and effective use of thermal insulation in buildings contribute towards reducing the required air-conditioning or central heating system ...

  15. Thermally Insulative Structural Connection for Cryogenic Propellant Tanks, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Paragon Space Development Corporation and Thin Red Line Aerospace (TRLA) propose a unique solution that thermally isolates the upper stage rocket from a payload on...

  16. Insulation commonality assessment (phase 1). Volume 2: Section 7.0 through 16.0. [evaluation of materials used for spacecraft thermal insulation

    Science.gov (United States)

    1973-01-01

    The heat transfer characteristics of various materials used for the thermal insulation of spacecraft are discussed. Techniques for conducting thermal performance analysis, structural performance analysis, and dynamic analysis are described. Processes for producing and finishing the materials are explained. The methods for determining reliability, system safety, materials tests, and design effectiveness are explained.

  17. Data on anti-insulation detection via Point of Thermal Inflexion (PTI in 1248 cases; 13 climates, four occupancy profiles, six wall configurations and four insulation levels

    Directory of Open Access Journals (Sweden)

    Yasin M. Idris

    2017-06-01

    Full Text Available The data in this article are the simulation results of 1248 cases that were carried out to detect anti-insulation behaviour in the article titled “Anti-insulation mitigation by altering the envelope layers’ configuration” (Idris and Mae, 2017 [1]. These cases are generated by a matrix of 13 climates, 6 envelope layer configurations, 4 occupancy profiles and 4 levels of insulation thickness. The data are concerned with the annual cooling and heating loads of these cases. In addition, the data include the Point of Thermal Inflexion (PTI values and their anti-insulation pattern, when PTI is found. The PTI values are compiled in a single summary file and supplied as well. All These data are shared via this article where they can be reused in different ways, but mainly for serving researchers that intend to approach anti-insulation behaviour from different points of view.

  18. Effect of posture positions on the evaporative resistance and thermal insulation of clothing.

    Science.gov (United States)

    Wu, Y S; Fan, J T; Yu, W

    2011-03-01

    Evaporative resistance and thermal insulation of clothing are important parameters in the design and engineering of thermal environments and functional clothing. Past work on the measurement of evaporative resistance of clothing was, however, limited to the standing posture with or without body motion. Information on the evaporative resistance of clothing when the wearer is in a sedentary or supine posture and how it is related to that when the wearer is in a standing posture is lacking. This paper presents original data on the effect of postures on the evaporative resistance of clothing, thermal insulation and permeability index, based on the measurements under three postures, viz. standing, sedentary and supine, using the sweating fabric manikin-Walter. Regression models are also established to relate the evaporative resistance and thermal insulation of clothing under sedentary and supine postures to those under the standing posture. The study further shows that the apparent evaporated resistances of standing and sedentary postures measured in the non-isothermal condition are much lower than those in the isothermal condition. The apparent evaporative resistances measured using the mass loss method are generally lower than those measured using the heat loss method due to moisture absorption or condensation within clothing. STATEMENT OF RELEVANCE: The thermal insulation and evaporative resistance values of clothing ensembles under different postures are essential data for the ergonomics design of thermal environments (e.g. indoors or a vehicle's interior environment) and functional clothing. They are also necessary for the prediction of thermal comfort or duration of exposure in different environmental conditions.

  19. Tubular House - Form Follows Technology, Concrete Shell Structure with Inner Thermal Insulation

    Science.gov (United States)

    Idem, Robert; Kleczek, Paweł; Pawłowski, Krzysztof; Chudoba, Piotr

    2017-10-01

    The aim of this paper is the theoretical analysis of the possibilities and limitations of using an unconventional technology and the original architectural form stemming from it - the building with external construction and internal insulation. In Central European climatic conditions, the traditional solution for the walls of heated buildings relies on using external thermal insulation. This stems from building physics: it prevents interstitial condensation of water vapour in the wall. Internal insulation is used exceptionally. This is done e.g. in historical buildings undergoing thermal modernization (due to the impossibility of interfering with facade). In such cases, a thermal insulation layer is used on the internal wall surface, along with an additional layer of vapour barrier. The concept of building concerns the intentional usage of an internal insulation. In this case, the construction is a tight external reinforced concrete shell. The architectural form of such building is strongly interrelated with the technology, which was used to build it. The paper presents the essence of this concept in descriptive and drawing form. The basic elements of such building are described (the external construction, the internal insulation and ventilation). As a case study, authors present a project of a residential building along with the description of the applied materials and installation solutions, and the results obtained from thermal, humidity and energetic calculations. The discussion presents the advantages and disadvantages of the proposed concept. The basic advantage of this solution is potentially low building cost. This stems from minimizing the ground works, the simplicity of the joints and the outer finish, as well as from the possibility of prefabrication of the elements. The continuity of the thermal insulation allows to reduce the amount of thermal bridges. The applied technology and form are applicable most of all for small buildings, due to limited

  20. Heat transfer in Rockwool modelling and method of measurement. The effect of natural convection on heat transfer in fibrous materials

    Energy Technology Data Exchange (ETDEWEB)

    Dyrboel, Susanne

    1998-05-01

    Fibrous materials are some of the most widely used materials for thermal insulation. In this project the focus of interest has been on fibrous materials for building application. Interest in improving the thermal properties of insulation materials is increasing as legislation is being tightened to reduce the overall energy consumption. A knowledge of the individual heat transfer mechanisms - whereby heat is transferred within a particular material is an essential tool to improve continuously the thermal properties of the material. Heat is transferred in fibrous materials by four different transfer mechanisms: conduction through air, conduction through fibres, thermal radiation and convection. In a particular temperature range the conduction through air can be regarded as a constant, and conduction through fibres is an insignificant part of the total heat transfer. Radiation, however, constitutes 25-40% of the total heat transfer in light fibrous materials. In Denmark and a number of other countries convection in fibrous materials is considered as non-existent when calculating heat transmission as well as when designing building structures. Two heat transfer mechanisms have been the focus of the current project: radiation heat transfer and convection. The radiation analysis serves to develop a model that can be used in further work to gain a wider knowledge of the way in which the morphology of the fibrous material, i.e. fibre diameter distribution, fibre orientation distribution etc., influences the radiation heat transfer under different conditions. The convection investigation serves to examine whether considering convection as non-existent is a fair assumption to use in present and future building structures. The assumption applied in practically is that convection makes a notable difference only in very thick insulation, at external temperatures below -20 deg. C, and at very low densities. For large thickness dimensions the resulting heat transfer through the

  1. A lime based mortar for thermal insulation of medieval church vaults

    OpenAIRE

    Larsen, P.K.; Hansen, Tessa Kvist

    2016-01-01

    A new mortar for thermal insulation of medieval church vaults was tested in a full scale experiment in Annisse Church, DK. The mortar consists of perlite, a highly porous aggregate, mixed with slaked lime. These materials are compatible with the fired clay bricks and the lime mortar joints. The lambda-value of the insulation mortar is 0.08 W/m K or twice the lambda-value for mineral wool. The water vapour permeability is equal to a medieval clay brick, and it has three times higher capacity f...

  2. Production of thermal insulation blocks from bottom ash of fluidized bed combustion system.

    Science.gov (United States)

    Mandal, A K; Sinha, O P

    2017-08-01

    The issues of disposal and environmental problems are increased by the generation of bottom ash from the thermal power plants day by day; hence, its recycling is required. The present study aimed to make thermal insulation blocks using as raw material bottom ash and iron ore slime as a binder and to characterize their engineering properties. Two different fineness values of bottom ash were considered with varying amounts of iron ore slime (0-10%) to make the blocks. Blocks were dried followed by firing at 1000, 1100 and 1200°C, respectively. Cold crushing strength, density and thermal conductivity of these fired blocks showed increasing behaviour with firing temperature, fineness of bottom ash and iron ore slime content. In contrast, a reverse trend was observed in the case of porosity. With increasing firing temperature, the formation of lower melting phases like iron silicate followed by iron aluminium silicate was observed, which imparts the strength inside the blocks. The coarser particles of bottom ash increase the interparticle spaces, which enhances the apparent porosity, resulting in higher thermal insulation property in the blocks. Blocks having better thermal insulation property could be possible to make effectively from coarse bottom ash by adding iron ore slime as a binder.

  3. Characterization and comparative investigation of thermally insulating layers for the turbine and engine construction

    International Nuclear Information System (INIS)

    Steffens, H.D.; Fischer, U.

    1987-01-01

    The aim of the research project was to subject commercially produced thermal insulation layer systems, the use of which seems promising for engine and turbine construction, to standardized characterisation, testing and comparison. Suitable methods and procedures for this had to be developed, in order to be able to derive instructions for optimisation guidelines for the production of improved thermal insulation systems from the results of investigations. In the context of the research project, a computer-controlled thermal shock test rig was first developed, designed and built. This test rig was designed so that important test conditions, such as the heating and cooling speed could be varied reproducibly over wide ranges. Methods and procedures were worked out, which permit a comparative qualitative and quantitative characterisation of layers of thermal insulation. From metallographic investigations, the layer build-up, layer structure, porosity and crack morphology of the layers in the delivered state and after testing could be assessed and compared. X-ray fine structure investigations gave information on the type and quantity of the phases occurring in the ceramic layers. The results of thermal shock tests which were done at different temperature intervals depending on the substrate, could be correlated with the build-up of layers and supplied information on damage mechanisms and the course of failure. (orig.) With 57 figs., 16 tabs., 89 refs [de

  4. Transparent thermal insulation for prefabricated school buildings; Einsatz transparenter Waermedaemmung an Schulgebaeuden in praefabrizierter Bauweise

    Energy Technology Data Exchange (ETDEWEB)

    Russ, C. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany). Gruppe Solares Bauen; Buchmann, R. [Leipzigprojekt GmbH, Leipzig (Germany); Duesterhoeft, A. [Holz- und Leichtmetallbau GmbH, Leipzig (Germany)

    1997-12-31

    The existing schools in the new federal states built from prefabricated elements need to be modernized in order to reduce their energy demand. Fitting some 300 square metres of transparent thermal insulation to the south side of a house front may lead to a cut in its thermal energy demand by 74 per cent. This energy consumption is by 12 kWh per square metre lower than the one obtained with opaque thermal insulation. The results of the first demonstration project are described. (MSK) [Deutsch] Die in den neuen Bundeslaendern vorhandenen Schulen in vorgefertigter Bauweise sind energetisch sanierungsbeduerftig. Werden im Rahmen einer Sanierung ca. 300qm transparente Waermedaemmung an der suedorientierten Fassade eingesetzt, so kann der Heizwaermebedarf um 74% herabgesetzt werden. Das sind 12 kWh/qm weniger als bei dem vergleichsweisen Einsatz einer opaken Waermedaemmung. Im Folgenden werden die Ergebnisse des ersten Demonstrationsprojekts beschrieben.

  5. Transient thermal sensation and comfort resulting from adjustment of clothing insulation

    DEFF Research Database (Denmark)

    Goto, Tomonobu; Toftum, Jørn; Fanger, Povl Ole

    2003-01-01

    This study investigated the transient effects on human thermal responses of clothing adjustments. Two different levels of activity were tested, and the temperature was set to result in a warm or cool thermal sensation at each activity level. The subjects (12 females and 12 males) wore identical...... uniforms and were asked to take off or don a part of the uniform after they had adapted to the experimental conditions for more than 20 minutes. The results showed that the thermal sensation votes responded immediately to the adjustment of clothing insulation and reached a new steady-state level within 5...... minutes after both an increase and a decrease of clothing insulation, independent of the activity level....

  6. Thermal conductivity of magnetic insulators with strong spin-orbit coupling

    Science.gov (United States)

    Stamokostas, Georgios; Lapas, Panteleimon; Fiete, Gregory A.

    We study the influence of spin-orbit coupling on the thermal conductivity of various types of magnetic insulators. In the absence of spin-orbit coupling and orbital-degeneracy, the strong-coupling limit of Hubbard interactions at half filling can often be adequately described in terms of a pure spin Hamiltonian of the Heisenberg form. However, in the presence of spin-orbit coupling the resulting exchange interaction can become highly anisotropic. The effect of the atomic spin-orbit coupling, taken into account through the effect of magnon-phonon interactions and the magnetic order and excitations, on the lattice thermal conductivity of various insulating magnetic systems is studied. We focus on the regime of low temperatures where the dominant source of scattering is two-magnon scattering to one-phonon processes. The thermal current is calculated within the Boltzmann transport theory. We are grateful for financial support from NSF Grant DMR-0955778.

  7. Thermal properties evaluation of insulation in overpack containers for UF6 transport

    International Nuclear Information System (INIS)

    Frazier, J.L.

    1989-01-01

    Two types of insulation are currently in use in overpacks utilized to protect UF 6 during transport. Phenolic foam has been used in the family of UF 6 overpacks under US Department of Transportation Specifications. Recently new generation overpacks have been developed which utilize polyurethane foam. A comparative analysis was made of the thermal characteristics of the phenolic foam with that of polyurethane in two different densities. Thermal properties of materials vary with temperature with the relationship being a complex interaction of basic materials properties, processing variables, and environmental conditions. Typically, the thermal conductivity of a material increases with increasing temperature, and adequate thermal models of materials systems or structures require temperature dependent thermal properties such as conductivity. In the event of an overpack container exposed to a fire as a heat source, the thermal properties of the materials of construction will vary with temperature which varies with time. Environmental interactions will result in material properties changes which will be reflected in changes in thermal properties. The need to incorporate temperature dependent thermal properties into analytical finite element codes led to an experimental program to measure thermal properties, principally thermal conductivity, for the 21PF-1 overpack phenolic foam. The thermal conductivity-temperature relationship for this insulator has been measured from room temperature to over 1000F. An alternate UF 6 product cylinder overpack container has recently entered service; an overpack design incorporating polyurethane as the primary thermal resistance in place of the phenolic foam in a 2 1/2 ton cylinder overpack. Elevated temperature thermal properties measurements for the polyurethane material system are presented

  8. Assessment of thermal insulation materials and systems for building applications

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-06-01

    The primary goal of the study was to provide a proper foundation for decision making by the federal government, industry, and consumer. The report may be used to identify areas where new test methods and standards are needed to establish new programs for improving thermal performance of buildings, and as a basis for setting new or improved standards after the recommended test programs have been completed.

  9. RESEARCHES REGARDING USE OF TEXTILE MATERIALS FOR THERMAL INSULATION AT NEGATIVE TEMPERATURES

    Directory of Open Access Journals (Sweden)

    IOSUB Andrei

    2014-05-01

    Full Text Available Using thermal insulation in negative temperature acts to reduce heat flow to the cooled space or to objects that have a temperature below ambient temperature. To achieve economic operation of the space to be cooled insulation thickness and quality is an important factor. In this article we want to compare three products used in thermal insulation at negative temperatures: expanded polystyrene, non-woven and wool coats. The materials will be tested with a mechanical vapor compression refrigerator capable of producing temperatures in the range +4 .. -35 ° C, managed by a programmer Dixel capable of recording values between +40. .. -60 °C. Refrigeration insulation enclosure was made with 100 mm expanded polystyrene. On one side of the enclosure will be a cut of 250 * 250 mm, chosen in a central position where the material will be introduced to be tested. The dimensions of the samples are 250 * 250 * 60 mm. To check the insulation properties of materials it will be used a temperature logger capable of recording with two probes temperatures between +125...-40° C. One of the probes will be inserted inside the refrigerator and the second probe will be positioned to the outside of the test material adhered to an aluminum plate, in order to read a average temperature. The difference in thickness of the insulation shall be filled with non-woven material. Hardening the assembly will be made using a 6 mm thick OSB board. The materials will be tested in an identical ambient temperature and humidity.

  10. Utilization of Baggase Waste Based Materials as Improvement for Thermal Insulation of Cement Brick

    Directory of Open Access Journals (Sweden)

    Aminudin Eeydzah

    2017-01-01

    Full Text Available Building materials having low thermal load and low thermal conductivity will provide thermal comforts to the occupants in building. In an effort to reduce the use of high energy and waste products from the agricultural industry, sugarcane bagasse and banana bagasse has been utilize as an additive in the manufacture of cement brick. The aim of this study is to investigate the insulation and mechanical properties of brick that has been mixed with bagasse and its effectiveness as thermal insulation using heat flow meter. Waste bagasse is being treated using sodium hydroxide (NaOH and is characterized using SEM and XRF. The samples produced with two different dimensions of 50 mm × 50 mm × 50 mm and 215mm × 102.5mm × 65mm for thermal conductivity test. Next, the sample varies from 0% (control sample, 2%, 4%, 6%, 8% and 10% in order to determine the best mix proportion. The compressive strength is being tested for 7, 14 and 28 days of water curing. Results showed that banana bagasse has lower thermal conductivity compared to sugarcane bagasse used, with compressive strength of 15.6MPa with thermal conductivity 0.6W/m.K.

  11. Modeling thermal performance of exterior walls retrofitted from insulation and modified laterite based bricks materials

    Science.gov (United States)

    Wati, Elvis; Meukam, Pierre; Damfeu, Jean Claude

    2017-12-01

    Uninsulated concrete block walls commonly found in tropical region have to be retrofitted to save energy. The thickness of insulation layer used can be reduced with the help of modified laterite based bricks layer (with the considerably lower thermal conductivity than that of concrete block layer) during the retrofit building fabrics. The aim of this study is to determine the optimum location and distribution of different materials. The investigation is carried out under steady periodic conditions under the climatic conditions of Garoua in Cameroon using a Simulink model constructed from H-Tools (the library of Simulink models). Results showed that for the continuous air-conditioned space, the best wall configuration from the maximum time lag, minimum decrement factor and peak cooling transmission load perspective, is dividing the insulation layer into two layers and placing one at the exterior surface and the other layer between the two different massive layers with the modified laterite based bricks layer at the interior surface. For intermittent cooling space, the best wall configuration from the minimum energy consumption depends on total insulation thickness. For the total insulation thickness less than 8 cm approximately, the best wall configuration is placing the half layer of insulation material at the interior surface and the other half between the two different massive layers with the modified earthen material at the exterior surface. Results also showed that, the optimum insulation thickness calculated from the yearly cooling transmission (estimated only during the occupied period) and some economic considerations slightly depends on the location of that insulation.

  12. Bio-susceptibility of materials and thermal insulation systems used for historical buildings

    Science.gov (United States)

    Sterflinger, Katja; Ettenauer, Joerg; Pinar, Guadalupe

    2013-04-01

    In historical buildings of Northern countries high levels of energy are necessary to reach comfortable temperatures especially during the cold season. For this reason historical buildings are now also included in country specific regulations and ordinances to enhance the "energy - efficiency". Since an exterior insulation - as it is commonly used for modern architecture - is incompatible with monument protection, several indoor insulation systems based on historical and ecological materials, are on the market that should improve the thermic performance of a historical building. However, using organic materials as cellulose, loam, weed or wood, bears the risk of fungal growth and thus may lead to health problems in indoor environments. For this reason 5 different ecological indoor insulations systems were tested for their bio-susceptibility against various fungi both under natural conditions - after 2 years of installation in an historical building - and under laboratory conditions with high levels of relative humidity. Fungal growth was evaluated by classical isolation and cultivation as well as by molecular methods. The materials turned out to have a quite different susceptibility towards fungal contamination. Whereas insulations made of bloated Perlite (plaster and board) did not show any fungal growth after 2 years of exposition, the historical insulation made of loam and weed had high cell counts of various fungi. In laboratory experiments wooden softboard represented the best environment for fungal growth. As a result from this study, plaster and board made of bloated Perlite are presented as being the most appropriate materials for thermal insulation at least from the microbiological and hygienic point of view. For future investigations and for the monitoring of fungi in insulation and other building materials we suggest a molecular biology approach with a common protocol for quantitative DNA-extraction and amplification.

  13. Influence of thermal aging on AC leakage current in XLPE insulation

    Science.gov (United States)

    Geng, Pulong; Song, Jiancheng; Tian, Muqin; Lei, Zhipeng; Du, Yakun

    2018-02-01

    Cross-linked polyethylene (XLPE) has been widely used as cable insulation material because of its excellent dielectric properties, thermal stability and solvent resistance. To understand the influence of thermal aging on AC leakage current in XLPE insulation, all XLPE specimens were aged in oven in temperature range from 120 °C to 150 °C, and a series of tests were conducted on these XLPE specimens in different aging stages to measure the characteristic parameters, such as complex permittivity, leakage current and complex dielectric modulus. In the experiments, the effects of thermal aging, temperature and frequency on the AC leakage current in XLPE insulation were studied by analyzing complex dielectric constant and dielectric relaxation modulus spectrum, the change of relaxation peak and activation energy. It has been found that the active part of leakage current increases sharply with the increase of aging degree, and the test temperature and frequency have an influence on AC leakage current but the influence of test temperature is mainly reflected in the low frequency region. In addition, it has been shown by the experiments that the reactive part of leakage current exhibits a strong frequency dependent characteristic in the testing frequency range from 10-2 Hz to 105 Hz, but the influence of test temperature and thermal aging on it is relatively small.

  14. Influence of thermal aging on AC leakage current in XLPE insulation

    Directory of Open Access Journals (Sweden)

    Pulong Geng

    2018-02-01

    Full Text Available Cross-linked polyethylene (XLPE has been widely used as cable insulation material because of its excellent dielectric properties, thermal stability and solvent resistance. To understand the influence of thermal aging on AC leakage current in XLPE insulation, all XLPE specimens were aged in oven in temperature range from 120 °C to 150 °C, and a series of tests were conducted on these XLPE specimens in different aging stages to measure the characteristic parameters, such as complex permittivity, leakage current and complex dielectric modulus. In the experiments, the effects of thermal aging, temperature and frequency on the AC leakage current in XLPE insulation were studied by analyzing complex dielectric constant and dielectric relaxation modulus spectrum, the change of relaxation peak and activation energy. It has been found that the active part of leakage current increases sharply with the increase of aging degree, and the test temperature and frequency have an influence on AC leakage current but the influence of test temperature is mainly reflected in the low frequency region. In addition, it has been shown by the experiments that the reactive part of leakage current exhibits a strong frequency dependent characteristic in the testing frequency range from 10-2 Hz to 105 Hz, but the influence of test temperature and thermal aging on it is relatively small.

  15. Thermal Insulation and Strength Characteristics of Refractory Incorporating Natural Silica

    Directory of Open Access Journals (Sweden)

    Namboonruang Weerapol

    2016-01-01

    Full Text Available This work emphasizes on the studying of using silica to develop for the production of refractory materials. Materials are tested at the cured times of 7, 14 and 28 days. Results show that the cold crushing strength, flexural strength and bulk density increase with increasing cured times. On the other hand, the permanent linear change (PLC decreases with increasing cured times. It is also found that adding more silica contents can increase the durability of cracking property due to temperature changing. This study concludes that the silica refractory materials (SRM shows the enough quality to produce as the refractory material, type of the Conventional Cast/Pound (815 °C for the agroindustry using the thermal energy of Thailand.

  16. Cryogenic Thermal Performance Testing of Bulk-Fill and Aerogel Insulation Materials

    Science.gov (United States)

    Scholtens, B. E.; Fesmire, J. E.; Sass, J. P.; Augustynowicz, S. D.; Heckle, K. W.

    2007-01-01

    The research testing and demonstration of new bulk-fill materials for cryogenic thermal insulation systems was performed by the Cryogenics Test Laboratory at NASA Kennedy Space Center. Thermal conductivity testing under actual-use cryogenic conditions is a key to understanding the total system performance encompassing engineering, economics, and materials factors. A number of bulk fill insulation materials, including aerogel beads, glass bubbles, and perlite powder, were tested using a new cylindrical cryostat. Boundary temperatures for the liquid nitrogen boil-off method were 293 K and 78 K. Tests were performed as a function of cold vacuum pressure from high vacuum to no vacuum conditions. Results are compared with other complementary test methods in the range of 300 K to 20 K. Various testing techniques are shown to be required to obtain a complete understanding of the operating performance of a material and to provide data for answers to design engineering questions.

  17. An Apparatus to Measure Thermal Conductivity of Spray-On Foam Insulation

    Science.gov (United States)

    Barrios, M.; Sciver, S. W. Van

    2010-04-01

    A guarded-hot-plate apparatus has been developed to measure the thermal conductivity of various spray-on foam insulations (SOFI) at temperatures ranging from 20-300 K. The apparatus is designed to accept 222 mm (8.75″) diameter, 25.4 mm (1″) thick insulation samples, although different thicknesses can be accommodated. The apparatus is cooled with a two stage, pulse tube cryocooler, and the temperature is controlled with thin film etched foil heaters. This system allows thermal conductivity measurements to be made at low delta-T (ΔTheat flow axially through the sample. A gas handling system allows testing with different residual gases and pressures. To check for potential systematic errors, a finite element analysis was performed to examine temperature distribution and heat flow in the experimental chamber.

  18. Influence of Textile Structure and Silica Based Finishing on Thermal Insulation Properties of Cotton Fabrics

    Directory of Open Access Journals (Sweden)

    G. Rosace

    2016-01-01

    Full Text Available The aim of this work is to investigate the influence of weave structures and silica coatings obtained via sol-gel process on the thermal insulation properties of cotton samples. For this reason three main weave structures (plain, satin, and piqué of cotton fabric were selected with different yarn count, threads per cm, and mass per square meter values. Thereafter, only for the plain weave, the samples were padded using silica sol formed by hydrolysis and subsequent condensation of 3-glycidoxypropyltrimethoxysilane under acidic conditions. The silanized plain weave samples were characterized by TGA and FT-IR techniques. The thermal properties were measured with a home-made apparatus in order to calculate thermal conductivity, resistance, and absorption of all the treated fabric samples. The relationship between the thermal insulation properties of the plain weave fabrics and the concentration of sol solutions has been investigated. Fabrics weave and density were found to strongly influence the thermal properties: piqué always shows the lowest values and satin shows the highest values while plain weave lies in between. The thermal properties of treated high-density cotton plain weave fabric were proved to be strongly influenced by finishing agent concentration.

  19. A thermal porosimetry method to estimate pore size distribution in highly porous insulating materials.

    Science.gov (United States)

    Félix, V; Jannot, Y; Degiovanni, A

    2012-05-01

    Standard pore size determination methods such as mercury porosimetry, nitrogen sorption, microscopy, or x-ray tomography are not always applicable to highly porous, low density, and thus very fragile materials. For this kind of materials, a method based on thermal characterization is proposed. Indeed, the thermal conductivity of a highly porous and insulating medium is significantly dependent on the thermal conductivity of the interstitial gas that depends on both gas pressure and size of the considered pore (Knudsen effect). It is also possible to link the pore size with the thermal conductivity of the medium. Thermal conductivity measurements are realized on specimens placed in an enclosure where the air pressure is successively set to different values varying from 10(-1) to 10(5) Pa. Knowing the global porosity ratio, an effective thermal conductivity model for a two-phase air-solid material based on a combined serial-parallel model is established. Pore size distribution can be identified by minimizing the sum of the quadratic differences between measured values and modeled ones. The results of the estimation process are the volume fractions of the chosen ranges of pore size. In order to validate the method, measurements done on insulating materials are presented. The results are discussed and show that pore size distribution estimated by the proposed method is coherent.

  20. Potential of Hollow Glass Microsphere as Cement Replacement for Lightweight Foam Concrete on Thermal Insulation Performance

    Directory of Open Access Journals (Sweden)

    Shahidan Shahiron

    2017-01-01

    Full Text Available Global warming can be defined as a gradual increase in the overall temperature of the earth’s atmosphere. A lot of research work has been carried out to reduce that heat inside the residence such as the used of low density products which can reduce the self-weight, foundation size and construction costs. Foamed concrete it possesses high flow ability, low self-weight, minimal consumption of aggregate, controlled low strength and excellent thermal insulation properties. This study investigate the characteristics of lightweight foamed concrete where Portland cement (OPC was replaced by hollow glass microsphere (HGMs at 0%, 3%, 6%, 9% by weight. The density of wet concrete is 1000 kg/m3 were tested with a ratio of 0.55 for all water binder mixture. Lightweight foamed concrete hollow glass microsphere (HGMs produced were cured by air curing and water curing in tank for 7, 14 and 28 days. A total of 52 concrete cubes of size 100mm × 100mm × 100mm and 215mm × 102.5mm × 65mm were produced. Furthermore, Scanning Electron Microscope (SEM and X-ray fluorescence (XRF were carried out to study the chemical composition and physical properties of crystalline materials in hollow glass microspheres. The experiments involved in this study are compression strength, water absorption test, density and thermal insulation test. The results show that the compressive strength of foamed concrete has reached the highest in 3% of hollow glass microsphere with less water absorption and less of thermal insulation. As a conclusion, the quantity of hollow glass microsphere plays an important role in determining the strength and water absorption and also thermal insulation in foamed concrete and 3% hollow glass microspheres as a replacement for Portland cement (OPC showed an optimum value in this study as it presents a significant effect than other percentage.

  1. Potential of Hollow Glass Microsphere as Cement Replacement for Lightweight Foam Concrete on Thermal Insulation Performance

    OpenAIRE

    Shahidan Shahiron; Aminuddin Eeydzah; Mohd Noor Khairiyah; Ramzi Hannan Nurul Izzati Raihan; Saiful Bahari Nur Amira

    2017-01-01

    Global warming can be defined as a gradual increase in the overall temperature of the earth’s atmosphere. A lot of research work has been carried out to reduce that heat inside the residence such as the used of low density products which can reduce the self-weight, foundation size and construction costs. Foamed concrete it possesses high flow ability, low self-weight, minimal consumption of aggregate, controlled low strength and excellent thermal insulation properties. This study investigate ...

  2. Introduction to the adhesive bonding session. [foam system for attaching thermal insulation on space shuttle

    Science.gov (United States)

    Mccarty, J. E.

    1972-01-01

    Space shuttle unique requirements call for the development of a specific adhesive system to reliable attach reusable surface insulation. A low density foam system has been developed that provides strain isolation from the support structure and remains structurally stable in space shuttle thermal environment. Surface preparation and its stabilization by an adhesive primer system are the most important factors in preventing corrosion from reducing the reliability and durability of the adhesive bonding component.

  3. EVALUATION OF THERMAL INSULATION FOR THREE DIFFERENT MATERIALS USED IN CONSTRUCTION AND COMPLETION OF EXTERNAL WALLS

    Directory of Open Access Journals (Sweden)

    Marcio Carlos Navroski

    2010-05-01

    Full Text Available Summers increasingly hot are bringing large thermal problems within homes and businesses, leading to increased demand for installation of air conditioners and the consequent high energy consumption. Constructions with thermal insulation on its external walls thatcould reduce energy use or even supply the use of such equipment. Due to these factors the present study was to evaluate the insulation in three boxes built with different materials, one made of wooden boards with plain walls, and two built with plywood, wall insulation andinterior walls filled with rice husk and Styrofoam®. The boxes were built after placed in drying oven at 40 °C, then noted the temperature inside the same interval every five minutes using a digital thermometer. The box with inner Styrofoam® showed the lowest variation among the three evaluated, followed by the box of rice husk. These two materials also showed good thermal initial, unlike the box built only with wood, which showed a large interiorheating, lay in a drying oven.

  4. Effect of Insulation Thickness on Thermal Stratification in Hot Water Tanks

    Directory of Open Access Journals (Sweden)

    Burak KURŞUN

    2018-03-01

    Full Text Available One of the important factors to be considered in increasing the efficiency of hot water storage tanks used for thermal energy storage is thermal stratification. Reducing the temperature of the water at the base of the tank provides more utilization of the energy of the heat source during the heating of the water and improves the efficiency of the system. In this study, the effect of the insulation thickness on the outer surface of the tank and the ratio of the tank diameter to the height (D/H on the thermal stratification was investigated numerically. Numerical analyzes were carried out for the condition that the insulation thickness was constant and variable in the range of D/H=0,3-1. Water was used as the heat storage fluid and the analysis results were obtained for eight hours cooling period. Numerical results showed that the temperature difference between the bottom and top surfaces of the tank increased between 7-9 ° C for the range of D / H = 0,3-1 with changing the insulation thickness.

  5. Needle-Bonded Electromagnetic Shielding Thermally Insulating Nonwoven Composite Boards: Property Evaluations

    Directory of Open Access Journals (Sweden)

    Jia-Horng Lin

    2016-10-01

    Full Text Available Complicated environmental problems inevitably arise when technology advances. One major environmental problem is the presence of electromagnetic radiation. Long-term exposure to electromagnetic radiation can damage people’s health in many ways. Therefore, this study proposes producing composite boards with electromagnetic shielding effectiveness and thermal insulation by utilizing the structures and properties of materials. Different combinations of flame-retardant polyester fiber (FR fiber, recycled far-infrared polyester fiber (FI fiber, and 4D low-melting-point fibers (LM fiber were made into flame-retardant and thermally insulating matrices. The matrices and carbon fiber (CF woven fabric in a sandwich-structure were needle-punched in order to be tightly compact, and then circularly heat dried in order to have a heat set and reinforced structure. The test results indicate that Polyester (PET/CF composite boards are mechanically strong and have thermal insulation and electromagnetic shielding effectiveness at a frequency between 0.6 MHz and 3 GHz.

  6. Surface Thermal Insulation and Pipe Cooling of Spillways during Concrete Construction Period

    Directory of Open Access Journals (Sweden)

    Wang Zhenhong

    2014-01-01

    Full Text Available Given that spillways adopt a hydraulic thin concrete plate structure, this structure is difficult to protect from cracks. The mechanism of the cracks in spillways shows that temperature stress is the major reason for cracks. Therefore, an effective way of preventing cracks is a timely and reasonable temperature-control program. Studies show that one effective prevention method is surface thermal insulation combined with internal pipe cooling. The major factors influencing temperature control effects are the time of performing thermal insulation and the ways of internal pipe cooling. To solve this problem, a spillway is taken as an example and a three-dimensional finite element program and pipe cooling calculation method are adopted to conduct simulation calculation and analysis on the temperature fields and stress fields of concretes subject to different temperature-control programs. The temperature-control effects are then compared. Optimization results show that timely and reasonable surface thermal insulation and water-flowing mode can ensure good temperature-control and anticrack effects. The method has reference value for similar projects.

  7. Development and validation of purged thermal protection systems for liquid hydrogen fuel tanks of hypersonic vehicles

    Science.gov (United States)

    Helenbrook, R. D.; Colt, J. Z.

    1977-01-01

    An economical, lightweight, safe, efficient, reliable, and reusable insulation system was developed for hypersonic cruise vehicle hydrogen fuel tanks. Results indicate that, a nitrogen purged, layered insulation system with nonpermeable closed-cell insulation next to the cryogenic tank and a high service temperature fibrous insulation surrounding it, is potentially an attractive solution to the insulation problem. For the postulated hypersonic flight the average unit weight of the purged insulation system (including insulation, condensate and fuel boil off) is 6.31 kg/sq m (1.29 psf). Limited cyclic tests of large specimens of closed cell polymethacrylimide foam indicate it will withstand the expected thermal cycle.

  8. Transient plane source (tps) sensors for simultaneous measurements of thermal conductivity and thermal diffusivity of insulators, fluids and conductors

    Science.gov (United States)

    Maqsood, Asghari; Anis-ur-Rehman, M.

    2013-12-01

    Thermal conductivity and thermal diffusivity are two important physical properties for designing any food engineering processes1. The knowledge of thermal properties of the elements, compounds and different materials in many industrial applications is a requirement for their final functionality. Transient plane source (tps) sensors are reported2 to be useful for the simultaneous measurement of thermal conductivity, thermal diffusivity and volumetric heat capacity of insulators, conductor liquids3 and high-TC superconductors4. The tps-sensor consists of a resistive element in the shape of double spiral made of 10 micrometer thick Ni-foils covered on both sides with 25 micrometer thick Kapton. This sensor acts both as a heat source and a resistance thermometer for recording the time dependent temperature increase. From the knowledge of the temperature co-efficient of the metal spiral, the temperature increase of the sensor can be determined precisely by placing the sensor in between two surfaces of the same material under test. This temperature increase is then related to the thermal conductivity, thermal diffusivity and volumetric heat capacity by simple relations2,5. The tps-sensor has been used to measure thermal conductivities from 0.001 Wm-1K-1to 600 Wm-1K-1 and temperature ranges covered from 77K- 1000K. This talk gives the design, advantages and limitations of the tpl-sensor along with its applications to the measurementof thermal properties in a variety of materials.

  9. Transient plane source (tps) sensors for simultaneous measurements of thermal conductivity and thermal diffusivity of insulators, fluids and conductors

    International Nuclear Information System (INIS)

    Maqsood, Asghari; Anis-ur-Rehman, M

    2013-01-01

    Thermal conductivity and thermal diffusivity are two important physical properties for designing any food engineering processes 1 . The knowledge of thermal properties of the elements, compounds and different materials in many industrial applications is a requirement for their final functionality. Transient plane source (tps) sensors are reported 2 to be useful for the simultaneous measurement of thermal conductivity, thermal diffusivity and volumetric heat capacity of insulators, conductor liquids 3 and high-T C superconductors 4 . The tps-sensor consists of a resistive element in the shape of double spiral made of 10 micrometer thick Ni-foils covered on both sides with 25 micrometer thick Kapton. This sensor acts both as a heat source and a resistance thermometer for recording the time dependent temperature increase. From the knowledge of the temperature co-efficient of the metal spiral, the temperature increase of the sensor can be determined precisely by placing the sensor in between two surfaces of the same material under test. This temperature increase is then related to the thermal conductivity, thermal diffusivity and volumetric heat capacity by simple relations 2,5 . The tps-sensor has been used to measure thermal conductivities from 0.001 Wm −1 K −1 to 600 Wm −1 K −1 and temperature ranges covered from 77K– 1000K. This talk gives the design, advantages and limitations of the tpl-sensor along with its applications to the measurementof thermal properties in a variety of materials

  10. Design Considerations for Thermally Insulating Structural Sandwich Panels for Hypersonic Vehicles

    Science.gov (United States)

    Blosser, Max L.

    2016-01-01

    Simplified thermal/structural sizing equations were derived for the in-plane loading of a thermally insulating structural sandwich panel. Equations were developed for the strain in the inner and outer face sheets of a sandwich subjected to uniaxial mechanical loads and differences in face sheet temperatures. Simple equations describing situations with no viable solution were developed. Key design parameters, material properties, and design principles are identified. A numerical example illustrates using the equations for a preliminary feasibility assessment of various material combinations and an initial sizing for minimum mass of a sandwich panel.

  11. Extreme temperature stability of thermally insulating graphene-mesoporous-silicon nanocomposite

    Science.gov (United States)

    Kolhatkar, Gitanjali; Boucherif, Abderraouf; Rahim Boucherif, Abderrahim; Dupuy, Arthur; Fréchette, Luc G.; Arès, Richard; Ruediger, Andreas

    2018-04-01

    We demonstrate the thermal stability and thermal insulation of graphene-mesoporous-silicon nanocomposites (GPSNC). By comparing the morphology of GPSNC carbonized at 650 °C as-formed to that after annealing, we show that this nanocomposite remains stable at temperatures as high as 1050 °C due to the presence of a few monolayers of graphene coating on the pore walls. This does not only make this material compatible with most thermal processes but also suggests applications in harsh high temperature environments. The thermal conductivity of GPSNCs carbonized at temperatures in the 500 °C-800 °C range is determined through Raman spectroscopy measurements. They indicate that the thermal conductivity of the composite is lower than that of silicon, with a value of 13 ± 1 W mK-1 at room temperature, and not affected by the thin graphene layer, suggesting a role of the high concentration of carbon related-defects as indicated by the high intensity of the D-band compared to G-band of the Raman spectra. This morphological stability at high temperature combined with a high thermal insulation make GPSNC a promising candidate for a broad range of applications including microelectromechanical systems and thermal effect microsystems such as flow sensors or IR detectors. Finally, at 120 °C, the thermal conductivity remains equal to that at room temperature, attesting to the potential of using our nanocomposite in devices that operate at high temperatures such as microreactors for distributed chemical conversion, solid oxide fuel cells, thermoelectric devices or thermal micromotors.

  12. THERMAL INSULATION PROPERTIES RESEARCH OF THE COMPOSITE MATERIAL WATER GLASS–GRAPHITE MICROPARTICLES

    Directory of Open Access Journals (Sweden)

    V. A. Gostev

    2014-05-01

    Full Text Available Research results for the composite material (CM water glass–graphite microparticles with high thermal stability and thermal insulation properties are given. A composition consisting of graphite (42 % by weight, water glass Na2O(SiO2n (50% by weight and the hardener - sodium silicofluoric Na2SiF6 (8% by weight. Technology of such composition receipt is suggested. Experimental samples of the CM with filler particles (graphite and a few microns in size were obtained. This is confirmed by a study of samples by X-ray diffraction and electron microscopy. The qualitative and quantitative phase analysis of the CM structure is done. Load limit values leading to the destruction of CM are identified. The character of the rupture surface is detected. Numerical values of specific heat and thermal conductivity are defined. Dependence of the specific heat capacity and thermal conductivity on temperature at monotonic heating is obtained experimentally. Studies have confirmed the increased thermal insulation properties of the proposed composition. CM with such characteristics can be recommended as a coating designed to reduce heat losses and resistant to high temperatures. Due to accessibility and low cost of its components the proposed material can be produced on an industrial scale.

  13. Evaluation of mechanical and thermal properties of insulation materials for HTS power devices at liquid nitrogen temperature

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hyung Seop; Diaz, Mark Angelo [Dept. of Mechanical Design Engineering, Andong National University, Andong (Korea, Republic of)

    2017-06-15

    In superconducting power devices including power cables in which high temperature superconducting (HTS) tapes are utilized, a reliable electrical insulation should be achieved for its maximum performance. For an efficient design of HTS superconducting devices, a comparative evaluation of the mechanical and thermal propperties for various insulation materials at cryogenic temperatures is required. Especially, in the process of the property evaluation of the sheet-shaped insulation materials, anisotropy according to the machining direction should be considered because the mechanical and thermal properties are significantly influenced by the sample orientation. In this study, the cryogenic thermal and mechanical properties of various insulation material sheets such as PPLP, Cryoflex, Teflon, and Kapton were determined considering sample orientation. All samples tested at cryogenic temperature showed significantly higher tensile strength as compared with that of room temperature. The ultimate tensile strength at both temperature conditions significantly depended upon the sample orientation. The thermal properties of the insulation materials exhibited a slight difference among samples depending on the orientation: for the PPLP and Cryoflex, the CD orientation showed larger thermal contraction up to 77 K as compared to the MD one. MD samples in PPLP and Cryoflex showed a lower CTE and thermal contraction which made it more promising as an insulation material due to its comparable CTE with HTS CC tapes.

  14. Preparation and thermal insulation performance of cast-in-situ phosphogypsum wall.

    Science.gov (United States)

    Li, Yubo; Dai, Shaobin; Zhang, Yichao; Huang, Jun; Su, Ying; Ma, Baoguo

    2018-01-01

    The mass accumulation of phosphogypsum has caused serious environmental pollution, which has become a worldwide problem. Gypsum is a kind of green building material, which is lighter, has better heat and sound insulation performance, and is easier to recycle compared to cement. The application of cast-in-situ phosphogypsum wall could consume a large amount of pollutant, and improve the efficiency of building construction. The preparation and thermal insulation performance of cast-in-situ phosphogypsum wall were investigated. The property of phosphogypsum-fly ash-lime (PFL) triad cementing materials, the adaptability of retarders and superplasticizers, and the influences of vitrified microsphere as aggregates were explored. Thus, the optimum mix was proposed. Thermal insulation performance tests and ANSYS simulation of this material was carried out. Optimal structures based on heat channels and the method of calculation determining related parameters were proposed, which achieved a 12.3% reduction in the heat transfer coefficient of the wall. With good performance, phosphogypsum could be used in cast-in-situ walls. This paper provides the theoretical basis for the preparation and energy-saving application of phosphogypsum in the walls of buildings.

  15. Acoustic and Thermal Testing of an Integrated Multilayer Insulation and Broad Area Cooling Shield System

    Science.gov (United States)

    Wood, Jessica J.; Foster, Lee W.

    2013-01-01

    A Multilayer Insulation (MLI) and Broad Area Cooling (BAC) shield thermal control system shows promise for long-duration storage of cryogenic propellant. The NASA Cryogenic Propellant Storage and Transfer (CPST) project is investigating the thermal and structural performance of this tank-applied integrated system. The MLI/BAC Shield Acoustic and Thermal Test was performed to evaluate the MLI/BAC shield's structural performance by subjecting it to worst-case launch acoustic loads. Identical thermal tests using Liquid Nitrogen (LN2) were performed before and after the acoustic test. The data from these tests was compared to determine if any degradation occurred in the thermal performance of the system as a result of exposure to the acoustic loads. The thermal test series consisted of two primary components: a passive boil-off test to evaluate the MLI performance and an active cooling test to evaluate the integrated MLI/BAC shield system with chilled vapor circulating through the BAC shield tubes. The acoustic test used loads closely matching the worst-case envelope of all launch vehicles currently under consideration for CPST. Acoustic test results yielded reasonable responses for the given load. The thermal test matrix was completed prior to the acoustic test and successfully repeated after the acoustic test. Data was compared and yielded near identical results, indicating that the MLI/BAC shield configuration tested in this series is an option for structurally implementing this thermal control system concept.

  16. Comparative Analysis of the Thermal Insulation of Traditional and Newly Designed Protective Clothing for Foundry Workers

    Directory of Open Access Journals (Sweden)

    Iwona Frydrych

    2016-09-01

    Full Text Available An objective of the undertaken research was checking the applicability of aluminized basalt fabrics for the production of clothing for foundry workers. The results of flammability, the resistance to contact, convective and radiation heat, as well as the resistance to big molten metal splashes confirmed the thesis of applicability of the packages with the use of aluminized basalt fabric content for the assumed purpose; therefore, such protective clothing was produced. Thermal comfort of foundry workers is very important and related to many factors, i.e., the structure of the protective clothing package, the number of layers, their thickness, the distance between the body and appropriate underwear. In the paper, a comparison of the results of thermal insulation measurement of two kinds of protective clothing is presented: the traditional one made of aluminized glass fabrics and the new one made of aluminized basalt fabrics. Measurements of clothing thermal insulation were conducted using a thermal manikin dressed in the protective clothing and three kinds of underwear products covering the upper and lower part of the manikin.

  17. Thermal conductivity of aerogel blanket insulation under cryogenic-vacuum conditions in different gas environments

    Science.gov (United States)

    E Fesmire, J.; Ancipink, J. B.; Swanger, A. M.; White, S.; Yarbrough, D.

    2017-12-01

    Thermal conductivity of low-density materials in thermal insulation systems varies dramatically with the environment: cold vacuum pressure, residual gas composition, and boundary temperatures. Using a reference material of aerogel composite blanket (reinforcement fibers surrounded by silica aerogel), an experimental basis for the physical heat transmission model of aerogel composites and other low-density, porous materials is suggested. Cryogenic-vacuum testing between the boundary temperatures of 78 K and 293 K is performed using a one meter cylindrical, absolute heat flow calorimeter with an aerogel blanket specimen exposed to different gas environments of nitrogen, helium, argon, or CO2. Cold vacuum pressures include the full range from 1×10-5 torr to 760 torr. The soft vacuum region, from about 0.1 torr to 10 torr, is complex and difficult to model because all modes of heat transfer - solid conduction, radiation, gas conduction, and convection - are significant contributors to the total heat flow. Therefore, the soft vacuum tests are emphasized for both heat transfer analysis and practical thermal data. Results for the aerogel composite blanket are analyzed and compared to data for its component materials. With the new thermal conductivity data, future applications of aerogel-based insulation systems are also surveyed. These include Mars exploration and surface systems in the 5 torr CO2 environment, field joints for vacuum-jacketed cryogenic piping systems, common bulkhead panels for cryogenic tanks on space launch vehicles, and liquid hydrogen cryofuel systems with helium purged conduits or enclosures.

  18. Influence of gamma ray irradiation on thermal conductivity of bismaleimide-triazine-based insulation tape at cryogenic temperature

    Science.gov (United States)

    Yang, Y.; Yoshida, M.; Idesaki, A.; Ogitsu, T.

    2018-01-01

    Recent accelerator-based experiments for particle physics require the superconducting magnets that can be operated under high radiation environment. An electrical insulation tape, which is composed of polyimide film and a boron free glass fabric pre-impregnated with epoxy resin blended with bismaleimide-triazine resin, is developed to enhance the radiation tolerance for superconducting magnets. Since the thermal conductivity of insulation tape is one of key parameters that affects the coil temperature during the operation, the influence of gamma-ray irradiation on the thermal conductivity of the insulation tape is investigated with a maximum dose of 5 MGy. The thermal conductivity is measured at cryogenic temperature from 5 K to 20 K cooled by a Gifford-McMahon cryocooler. By comparing the thermal conductivity before and after the gamma ray irradiation, no significant degradation on the thermal conductivity has been observed.

  19. A system for the thermal insulation of a pre-stressed concrete vessel

    International Nuclear Information System (INIS)

    Aubert, Gilles; Petit, Guy.

    1975-01-01

    This invention concerns the thermal insulation of a pre-stressed concrete vessel for a pressurised water nuclear reactor, this vessel being fitted internally with a leak-proof metal lining. Two rings are placed at the lower and upper parts of the vessel respectively. The upper ring is closed with a cover. These rings differ in diameter, are fitted with a metal insulating and mark the limits of a chamber between the vaporisable fluid and the internal wall of the vessel. This chamber is filled with a fluid in the liquid phase up to the liquid/vapor interface level of the fluid and with a gas above that level, the covering of the rings forming a cold fluid liquid seal. Each ring is supported by the vessel. Leak-proof components take up the radial expansion of the rings [fr

  20. Efficient Thermal Insulation of Passive House with Curved Façades in Cold Climate

    Directory of Open Access Journals (Sweden)

    Aznabaev Askar

    2016-01-01

    Full Text Available In this paper there is exploration of the possibility of creating effective sealed building envelope in zero energy building (ZEB with unique façades. This article describes passive and active measures of decrease of thermal loss through enclosure structures, usage of modern insulation materials; positive effect of rationalization of the façade orientation and form of a building in a plan; on the base of existing architecture concept structural solutions of building envelope are suggested. Using thermal FEA the enclosure structure was optimized. The results of modeling of units and elements of building envelope are: heat transfer coefficient U-value for heterogeneous multilayer structure, picture of temperature distribution and magnitude of the thermal conductivity and temperature of internal wall surface.

  1. Numerical Calculation of Transient Thermal Characteristics in Gas-Insulated Transmission Lines

    Directory of Open Access Journals (Sweden)

    Hongtao Li

    2013-11-01

    Full Text Available For further knowledge of the thermal characteristics in gas-insulated transmission lines (GILs installed above ground, a finite-element model coupling fluid field and thermal field is established, in which the corresponding assumptions and boundary conditions are given.  Transient temperature rise processes of the GIL under the conditions of variable ambient temperature, wind velocity and solar radiation are respectively investigated. Equivalent surface convective heat transfer coefficient and heat flux boundary conditions are updated in the analysis process. Unlike the traditional finite element methods (FEM, the variability of the thermal properties with temperature is considered. The calculation results are validated by the tests results reported in the literature. The conclusion provides method and theory basis for the knowledge of transient temperature rise characteristics of GILs in open environment.

  2. Effect of TiO2 pigment gradation on the properties of thermal insulation coatings

    Science.gov (United States)

    Shen, Lu-wei; Zhang, Ya-mei; Zhang, Pei-gen; Shi, Jin-jie; Sun, Zheng-ming

    2016-12-01

    This study was designed to evaluate the thermal performance and mechanical properties of coatings with different gradations of TiO2 pigments. The solar reflectance, cooling performance, wash resistance, and film adhesion strength of the coatings were investigated. The influence of TiO2 powder gradation on the final properties of the coatings was studed. The solar reflectance and the thermal insulation were observed to increase with increasing content of nanosized TiO2. The mechanical properties of the coatings, such as their wash resistance and film adhesion strength, were observed to increase with increased incorporation of nanosized TiO2. Such improvements in the properties of the coatings were attributed to the greater specific surface area and lower thermal conductivity of nanosized TiO2 particles compared to normal TiO2 particles.

  3. Thermally Activated Motion of Sodium Cations in Insulating Parent Low-Silica X Zeolite

    Science.gov (United States)

    Igarashi, Mutsuo; Jeglič, Peter; Mežnaršič, Tadej; Nakano, Takehito; Nozue, Yasuo; Watanabe, Naohiro; Arčon, Denis

    2017-07-01

    We report a 23Na spin-lattice relaxation rate, T1 - 1, in low-silica X zeolite. T1 - 1 follows multiple BPP-type behavior as a result of thermal motion of sodium cations in insulating material. The estimated lowest activation energy of 15 meV is much lower than 100 meV observed previously for sodium motion in heavily Na-loaded samples and is most likely attributed to short-distance jumps of sodium cations between sites within the same supercage.

  4. THE INFLUENCE OF ECOLOGICAL MATERIALS EMBEDDED INTO COMPOSITES UPON THE THERMAL INSULATING CAPACITY

    Directory of Open Access Journals (Sweden)

    Luminiţa-Maria BRENCI

    2014-12-01

    Full Text Available The paper presents the results of a research performed in order to design and manufacture composites that embed in their structure ecological raw materials, such as wood chips and hemp hurds. The thermal conductivity was determined for a temperature difference (ΔT of 200 C between the cold plate and warm plate and the measurements were done in eight points. The results showed that the best insulating composite material was obtained for the structure containing equal shares of wood chips and chopped hemp

  5. Thermal insulation research plan for the Energy Conversion and Utilization Technologies (ECUT) materials program

    Energy Technology Data Exchange (ETDEWEB)

    Fine, H.A.

    1986-08-01

    This report documents both the process and the output of the process of establishing a peer review panel primarily from the private sector to suggest research and development activities appropriate for government sponsorship through the US Department of Energy (DOE) Energy Conversion and Utilization Technologies (ECUT) Program on the subject of thermal insulation. We expect to use information and guidance from the document during the federal budgetary process to allow more informed decision making. All related results of that budgetary decision making will affect what the DOE or Oak Ridge National Laboratory (ORNL) can and will sponsor during this or subsequent years through detailed decisions of DOE and ORNL program managers.

  6. Comparative Study of the Comprehensive Properties of Multi walled Nano tubes/Polyurethane Nano fibrous Membranes with and without Thermal Treatment

    International Nuclear Information System (INIS)

    Liu, L.; Pan, Sh.

    2012-01-01

    This paper makes use of electro spinning technology to produce multi walled nano tubes and polyurethane (MWNTs/PU) composite nano fibrous membranes. A thermal treatment method was proposed to improve the comprehensive properties of the membranes. The morphology of the prepared nano materials was characterized by the SEM and TEM. Comprehensive properties, including thermal stability, conductivity, and mechanical properties, of the membranes with and without thermal treatment were investigated comparatively by TGA, DMA, resistivity measurement, and tensile testing, respectively. The results indicate that the proposed thermal treatment method could effectively improve the conductivity and mechanical properties of the nano materials. For the thermal treatment-based membrane filled with 3 wt.% of MWNTs, the conductivity reaches 8.29x10 -5 Scm -1 , which is nearly three orders higher than that of the untreated sample. Meanwhile, the tensile strength and modulus increase more than 50% after thermal treatment. It is expected that such improved nano materials may be potentially useful in composite reinforcement and electronic devices.

  7. Degradation mechanisms of cable insulation materials during radiation-thermal ageing in radiation environment

    Science.gov (United States)

    Seguchi, Tadao; Tamura, Kiyotoshi; Ohshima, Takeshi; Shimada, Akihiko; Kudoh, Hisaaki

    2011-02-01

    Radiation and thermal degradation of ethylene-propylene rubber (EPR) and crosslinked polyethylene (XLPE) as cable insulation materials were investigated by evaluating tensile properties, gel-fraction, and swelling ratio, as well as by the infrared (FTIR) analysis. The activation energy of thermal oxidative degradation changed over the range 100-120 °C for both EPR and XLPE. This may be attributed to the fact that the content of an antioxidant used as the stabilizer for polymers decreases by evaporation during thermal ageing at high temperatures. The analysis of antioxidant content and oxidative products in XLPE as a model sample showed that a small amount of antioxidant significantly reduced the extent of thermal oxidation, but was not effective for radiation induced oxidation. The changes in mechanical properties were well reflected by the degree of oxidation. A new model of polymer degradation mechanisms was proposed where the degradation does not take place by chain reaction via peroxy radical and hydro-peroxide. The role of the antioxidant in the polymer is the reduction of free radical formation in the initiation step in thermal oxidation, and it could not stop radical reactions for either radiation or thermal oxidation.

  8. Degradation mechanisms of cable insulation materials during radiation-thermal ageing in radiation environment

    Energy Technology Data Exchange (ETDEWEB)

    Seguchi, Tadao, E-mail: seguchi@aj.wakwak.co [Japan Atomic Energy Agency, Tokai 319-1195 (Japan); Tamura, Kiyotoshi; Ohshima, Takeshi; Shimada, Akihiko [Japan Atomic Energy Agency, Tokai 319-1195 (Japan); Kudoh, Hisaaki [University of Tokyo, Tokai 319-1195 (Japan)

    2011-02-15

    Radiation and thermal degradation of ethylene-propylene rubber (EPR) and crosslinked polyethylene (XLPE) as cable insulation materials were investigated by evaluating tensile properties, gel-fraction, and swelling ratio, as well as by the infrared (FTIR) analysis. The activation energy of thermal oxidative degradation changed over the range 100-120 {sup o}C for both EPR and XLPE. This may be attributed to the fact that the content of an antioxidant used as the stabilizer for polymers decreases by evaporation during thermal ageing at high temperatures. The analysis of antioxidant content and oxidative products in XLPE as a model sample showed that a small amount of antioxidant significantly reduced the extent of thermal oxidation, but was not effective for radiation induced oxidation. The changes in mechanical properties were well reflected by the degree of oxidation. A new model of polymer degradation mechanisms was proposed where the degradation does not take place by chain reaction via peroxy radical and hydro-peroxide. The role of the antioxidant in the polymer is the reduction of free radical formation in the initiation step in thermal oxidation, and it could not stop radical reactions for either radiation or thermal oxidation.

  9. Estimation of the thermal conductivity of hemp based insulation material from 3D tomographic images

    Science.gov (United States)

    El-Sawalhi, R.; Lux, J.; Salagnac, P.

    2016-08-01

    In this work, we are interested in the structural and thermal characterization of natural fiber insulation materials. The thermal performance of these materials depends on the arrangement of fibers, which is the consequence of the manufacturing process. In order to optimize these materials, thermal conductivity models can be used to correlate some relevant structural parameters with the effective thermal conductivity. However, only a few models are able to take into account the anisotropy of such material related to the fibers orientation, and these models still need realistic input data (fiber orientation distribution, porosity, etc.). The structural characteristics are here directly measured on a 3D tomographic image using advanced image analysis techniques. Critical structural parameters like porosity, pore and fiber size distribution as well as local fiber orientation distribution are measured. The results of the tested conductivity models are then compared with the conductivity tensor obtained by numerical simulation on the discretized 3D microstructure, as well as available experimental measurements. We show that 1D analytical models are generally not suitable for assessing the thermal conductivity of such anisotropic media. Yet, a few anisotropic models can still be of interest to relate some structural parameters, like the fiber orientation distribution, to the thermal properties. Finally, our results emphasize that numerical simulations on 3D realistic microstructure is a very interesting alternative to experimental measurements.

  10. Thermal degradation assessment of Kraft paper in power transformers insulated with natural esters

    International Nuclear Information System (INIS)

    Fernández, Inmaculada; Delgado, Fernando; Ortiz, Félix; Ortiz, Alfredo; Fernández, Cristina; Renedo, Carlos J.; Santisteban, Agustín

    2016-01-01

    Highlights: • Hot-spot temperatures in vegetable oil are higher than the ones in mineral oil. • Polymerization degree of Kraft paper in vegetable oil is higher than in mineral oil. • Poor cooling in vegetable oil could be offset by low degradation rate of paper. - Abstract: Kraft paper in combination with dielectric oil is the most common as insulation system used in power transformers. The most used oil in power transformers is mineral oil. However, dielectric oils based on natural esters possess some advantages in comparison with mineral oil such as higher biodegradability, fire safety and availability. Therefore, they might be the most ideal substitute for mineral oil. The introduction of a new material requires the evaluation of its degradation rate because this determines transformers’ life span. In order to assess the performance of new insulating systems based on vegetable oils, simulations to obtain the hot-spot temperatures in power transformers using vegetable oils and controlled laboratory experiments of ageing were carried out. The reason is that hot spot temperature inside windings of the oil-immersed power transformers is one of the main manifestations of the thermal stress which leads to aging of insulation systems.

  11. Effect of spacers on the thermal performance of an annular multi-layer insulation

    International Nuclear Information System (INIS)

    Haim, Y.; Weiss, Y.; Letan, R.

    2014-01-01

    The current study presents a model and is experimentally conducted in a system of 40 stainless steel coaxial foils, of nitrogen gas, entrapped between the foils, and of spacers, which are zirconia, spherical, 50 μm in size particles, widely dispersed in the gaps between the foils. The model, experimentally verified, relates to radiation between the foils, unobstructed by particles, to conduction in the nitrogen gas, and to conduction across the particles. The study was, in particular, aimed to measure the effective thermal conductivity of the particles and to assess its effect upon the array. At vacuum of 0.092 Pa, the effective thermal conductivity of the particles was 2.13 × 10 −4  W/m K, while the effective thermal conductivity of the array was 4.74 × 10 −4  W/m K. Thus, the low contribution of the particles conduction at vacuum conditions improves the insulation. It reaches 45% of the heat transfer rate. At atmospheric pressure, the effective thermal conductivity of the array reaches 4.5 × 10 −2  W/m K. There, the spacers contribution is negligible. - Highlights: •The multi-layer insulation of cylinder consists of foils separated by particles. •The particles are widely spaced in gaps. •Particles heat transfer rate is almost half of the total in vacuum. •At higher pressures the particles contribution is negligible. •The predicted thermal performance agrees with experimental results

  12. DESIGN SOLUTIONS FOR THERMAL INSULATION OF EXTERIOR WALLS OF CAST-IN-PLACE CONCRETE HIGH-RISE RESIDENTIAL BUILDINGS IN CENTRAL REGIONS OF СHINA

    Directory of Open Access Journals (Sweden)

    Bantserova Ol'ga Leonidovna

    2012-12-01

    Full Text Available A significant portion of the overall heat loss is due to the heat loss through the building envelope. According to the opinions of experts, the surface area of exterior walls has the insulation of about 65 % of the total envelope of apartment buildings; therefore, thermal protection of external walls of buildings is a key issue in ensuring the thermal performance of envelopes of apartment buildings. The author has developed design solutions that assure the thermal protection of exterior walls and that are aimed at identifying the optimal solution in terms of the location of insulation materials, their thermal performance and insulation of exterior walls of apartment buildings in central regions of China. The author presents a comparative analysis of the main methodologies of thermal insulation designated for the exterior walls of multi-storey residential buildings: internal and external insulation, as well as the insulation in-between the wall layers. The analyses of wall designs are based on the insulation performance, thermal insulation performance, methods of mounting different systems of insulation, and cost of work. As a result, practical recommendations originate from the statement that the most optimal designs of exterior walls of monolithic high-rise apartment buildings of central regions of China are those that have insulation on the outside of the building. They include layers of insulation made of extruded polystyrene, which is currently planned for use in the construction of high-rise monolithic residential buildings in central China.

  13. Synthesis of Hollow Silica Nanospheres by Sacrificial Polystyrene Templates for Thermal Insulation Applications

    Directory of Open Access Journals (Sweden)

    Linn Ingunn C. Sandberg

    2013-01-01

    Full Text Available Monodisperse polystyrene (PS spheres with controllable size have been synthesized by a straight forward and simple procedure. The as-synthesized PS spheres have a typical diameter ranging from ~180 nm to ~900 nm, where a reduced sphere size is obtained by increasing the polyvinylpyrrolidone (PVP/styrene weight ratio. The PS spheres function as sacrificial templates for the fabrication of hollow silica nanospheres (HSNSs for thermal insulation applications. By modifying the silica coating process, HSNSs with different surface roughness are obtained. All resulting HSNSs show typically a thermal conductivity of about 20 mW/(mK, indicating that the surface phonon scattering is probably not significant in these HSNS samples.

  14. Development of fly ash boards with thermal, acoustic and fire insulation properties.

    Science.gov (United States)

    Leiva, C; Arenas, C; Vilches, L F; Alonso-Fariñas, B; Rodriguez-Galán, M

    2015-12-01

    This paper presents an experimental analysis on a new board composed of gypsum and fly ashes from coal combustion, which are mutually compatible. Physical and mechanical properties, sound absorption coefficient, thermal properties and leaching test have been obtained. The mechanical properties showed similar values to other commercial products. As far as the acoustic insulation characteristics are concerned, sound absorption coefficients of 0.3 and 0.8 were found. The board presents a low thermal conductivity and a fire resistance higher than 50 min (for 4 cm of thickness). The leaching of trace elements was below the leaching limit values. These boards can be considered as suitable to be used in building applications as partitions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Influence of coatings on the thermal and mechanical processes at insulating glass units

    Science.gov (United States)

    Penkova, Nina; Krumov, Kalin; Surleva, Andriana; Geshkova, Zlatka

    2017-09-01

    Different coatings on structural glass are used in the advances transparent facades and window systems in order to increase the thermal performance of the glass units and to regulate their optical properties. Coated glass has a higher absorptance in the solar spectrum which leads to correspondent higher temperature in the presence of solar load compared to the uncoated one. That process results in higher climatic loads at the insulating glass units (IGU) and in thermal stresses in the coated glass elements. Temperature fields and gradients in glass panes and climatic loads at IGU in window systems are estimated at different coating of glazed system. The study is implemented by numerical simulation of conjugate heat transfer in the window systems at summer time and presence of solar irradiation, as well as during winter night time.

  16. Effects of thermal ageing and gamma radiations on ethylene-propylene based insulator of electric cables

    International Nuclear Information System (INIS)

    Baccaro, S.; D'Atanasio, P.

    1986-01-01

    This paper describes the effects of gamma radiation and thermal aging on cable insulator. The elastic properties degrade rapidly as the absorbed dose increases: the percent elongation at break attains nearly 100% value at 0.5 MGy absorbed dose. The gases evolved during the irradiation are mainly H 2 and CO 2 ; CO, CH 4 and C 2 H 6 are present in much lower concentrations. The damage undergone depends strongly on sequential radiation and thermal aging; the analysis of accelerated life test data by means of the Arrhenius model gave (1.23+-0.25) eV for the activation energy, about 1 eV higher than the values reported in the literature

  17. Improving thermal insulation of TC4 using YSZ-based coating and SiO2 aerogel

    Directory of Open Access Journals (Sweden)

    Lei Jin

    2015-04-01

    Full Text Available In this paper, air plasmas spray (APS was used to prepare YSZ and Sc2O3–YSZ (ScYSZ coating in order to improve the thermal insulation ability of TC4 alloy. SiO2 aerogel was also synthesized and affixed on TC4 titanium alloy to inhabit thermal flow. The microstructures, phase compositions and thermal insulation performance of three coatings were analyzed in detail. The results of thermal diffusivity test by a laser flash method showed that the thermal diffusivities of YSZ, Sc2O3–YSZ and SiO2 aerogel are 0.553, 0.539 and 0.2097×10−6 m2/s, respectively. Then, the thermal insulation performances of three kinds of coating were investigated from 20 °C to 400 °C using high infrared radiation heat flux technology. The experimental results indicated that the corresponding temperature difference between the top TC4 alloy (400 °C and the bottom surface of YSZ is 41.5 °C for 0.6 mm thickness coating. For 1 mm thickness coating, the corresponding temperature difference between the top TC4 alloys (400 °C and the bottom surface of YSZ, ScYSZ, SiO2 aerogel three specimens is 54, 54.6 and 208 °C, respectively. The coating thickness and species were found to influence the heat insulation ability. In these materials, YSZ and ScYSZ exhibited a little difference for heat insulation behavior. However, SiO2 aerogel was the best one among them and it can be taken as protection material on TC4 alloys. In outer space, SiO2 aerogel can meet the need of thermal insulation of TC4 of high-speed aircraft.

  18. Synthesis of Flexible Aerogel Composites Reinforced with Electrospun Nanofibers and Microparticles for Thermal Insulation

    Directory of Open Access Journals (Sweden)

    Huijun Wu

    2013-01-01

    Full Text Available Flexible silica aerogel composites in intact monolith of 12 cm were successfully fabricated by reinforcing SiO2 aerogel with electrospun polyvinylidene fluoride (PVDF webs via electrospinning and sol-gel processing. Three electrospun PVDF webs with different microstructures (e.g., nanofibers, microparticles, and combined nanofibers and microparticles were fabricated by regulating electrospinning parameters. The as-electrospun PVDF webs with various microstructures were impregnated into the silica sol to synthesize the PVDF/SiO2 composites followed by solvent exchange, surface modification, and drying at ambient atmosphere. The morphologies of the PVDF/SiO2 aerogel composites were characterized and the thermal and mechanical properties were measured. The effects of electrospun PVDF on the thermal and mechanical properties of the aerogel composites were evaluated. The aerogel composites reinforced with electrospun PVDF nanofibers showed intact monolith, improved strength, and perfect flexibility and hydrophobicity. Moreover, the aerogel composites reinforced with the electrospun PVDF nanofibers had the lowest thermal conductivity (0.028 W·m−1·K−1. It indicates that the electrospun PVDF nanofibers could greatly improve the mechanical strength and flexibility of the SiO2 aerogels while maintaining a lower thermal conductivity, which provides increasing potential for thermal insulation applications.

  19. Measuring the thermal insulation and evaporative resistance of sleeping bags using a supine sweating fabric manikin

    International Nuclear Information System (INIS)

    Wu, Y S; Fan, Jintu

    2009-01-01

    For testing the thermal insulation of sleeping bags, standard test methods and procedures using heated manikins are provided in ASTM F1720-06 and EN 13537:2002. However, with regard to the evaporative resistance of sleeping bags, no instrument or test method has so far been established to give a direct measurement. In this paper, we report on a novel supine sweating fabric manikin system for directly measuring the evaporative resistance of sleeping bags. Eleven sleeping bags were tested using the manikin under the isothermal condition, namely, both the mean skin temperature of the manikin and that of the environment were controlled to be the same at 35 °C, with the wind speed and ambient relative humidity at 0.3 m s −1 and 50%, respectively. The results showed that the novel supine sweating fabric manikin is reproducible and accurate in directly measuring the evaporative resistance of sleeping bags, and the measured evaporative resistance can be combined with thermal insulation to calculate the moisture permeability index of sleeping bags

  20. Nuclear reactor pressure vessel with an inner metal coating covered with a high temperature resistant thermal insulator

    International Nuclear Information System (INIS)

    1974-01-01

    The thermal insulator covering the metal coating of a reactor vessel is designed for resisting high temperatures. It comprises one or several porous layers of ceramic fibers or of stacked metal foils, covered with a layer of bricks or ceramic tiles. The latter are fixed in position by fasteners comprising pins fixed to the coating and passing through said porous layers and fasteners (nut or bolts) for individually fixing the bricks to said pins, whereas ceramic plugs mounted on said bricks or tiles provide for the thermal insulation of the pins and of the nuts or bolts; such a thermal insulation can be applied to high-temperature reactors or to fast reactors [fr

  1. Properties of Agro-Industrial Aerated Concrete as Potential Thermal Insulation for Building

    Directory of Open Access Journals (Sweden)

    Aminudin Eeydzah

    2016-01-01

    Full Text Available The present paper is aiming to provide an actual state of the development of non autoclaved Agro-Industrial aerated concrete by using multiple ashes as improvement of thermal behavior for building. The feasibility of Agro-Industrial wastes as lightweight concrete by utilizing the Palm Oil Fuel Ash (POFA as binder replacement and bottom ash as fine aggregate was investigated in this paper. Portland cement, bottom ash, aluminum powder and lime (Ca(OH2 were used in this study. The POFA was used to replace Portland cement and Hydrated Lime at 0%, 5%, 10% and 15% by weight and aluminum powder was added at 0.75% dry weight in order to form bubbles. The compressive strength, water absorption, porosity and the thermal conductivity test were carried out after the concrete were water cured for 7 days and later being exposed to the air and water until 28days. The results show that the 20% replacements give the optimum strength of 7.143MPa and 30% give the best thermal conductivity with 0.48W/mK. Hence, this study aim, was to develop an agro-industrial aerated concrete good in insulation but having an optimum strength. Hence, it has been found that the more the percentage of POFA is added the lower the thermal conductivity since the pore structure is increasing and by the optimization done, 30% replacement has been chosen as the best mix design for Agro-Industrial Aerated Concrete.

  2. Polyurethane Foams for Thermal Insulation Uses Produced from Castor Oil and Crude Glycerol Biopolyols.

    Science.gov (United States)

    Carriço, Camila S; Fraga, Thaís; Carvalho, Vagner E; Pasa, Vânya M D

    2017-07-02

    Rigid polyurethane foams were synthesized using a renewable polyol from the simple physical mixture of castor oil and crude glycerol. The effect of the catalyst (DBTDL) content and blowing agents in the foams' properties were evaluated. The use of physical blowing agents (cyclopentane and n-pentane) allowed foams with smaller cells to be obtained in comparison with the foams produced with a chemical blowing agent (water). The increase of the water content caused a decrease in density, thermal conductivity, compressive strength, and Young's modulus, which indicates that the increment of CO₂ production contributes to the formation of larger cells. Higher amounts of catalyst in the foam formulations caused a slight density decrease and a small increase of thermal conductivity, compressive strength, and Young's modulus values. These green foams presented properties that indicate a great potential to be used as thermal insulation: density (23-41 kg·m -3 ), thermal conductivity (0.0128-0.0207 W·m -1 ·K -1 ), compressive strength (45-188 kPa), and Young's modulus (3-28 kPa). These biofoams are also environmentally friendly polymers and can aggregate revenue to the biodiesel industry, contributing to a reduction in fuel prices.

  3. Investigation of the thermal resistance of timber attic spaces with reflective foil and bulk insulation, heat flow up

    Energy Technology Data Exchange (ETDEWEB)

    Belusko, M.; Bruno, F.; Saman, W. [Institute for Sustainable Systems and Technologies, University of South Australia, Mawson Lakes Boulevard, SA 5095 (Australia)

    2011-01-15

    An experimental investigation was undertaken in which the thermal resistance for the heat flow through a typical timber framed pitched roofing system was measured under outdoor conditions for heat flow up. The measured thermal resistance of low resistance systems such as an uninsulated attic space and a reflective attic space compared well with published data. However, with higher thermal resistance systems containing bulk insulation within the timber frame, the measured result for a typical installation was as low as 50% of the thermal resistance determined considering two dimensional thermal bridging using the parallel path method. This result was attributed to three dimensional heat flow and insulation installation defects, resulting from the design and construction method used. Translating these results to a typical house with a 200 m{sup 2} floor area, the overall thermal resistance of the roof was at least 23% lower than the overall calculated thermal resistance including two dimensional thermal bridging. When a continuous layer of bulk insulation was applied to the roofing system, the measured values were in agreement with calculated resistances representing a more reliable solution. (author)

  4. Protection against cold in prehospital care-thermal insulation properties of blankets and rescue bags in different wind conditions.

    Science.gov (United States)

    Henriksson, Otto; Lundgren, J Peter; Kuklane, Kalev; Holmér, Ingvar; Bjornstig, Ulf

    2009-01-01

    In a cold, wet, or windy environment, cold exposure can be considerable for an injured or ill person. The subsequent autonomous stress response initially will increase circulatory and respiratory demands, and as body core temperature declines, the patient's condition might deteriorate. Therefore, the application of adequate insulation to reduce cold exposure and prevent body core cooling is an important part of prehospital primary care, but recommendations for what should be used in the field mostly depend on tradition and experience, not on scientific evidence. The objective of this study was to evaluate the thermal insulation properties in different wind conditions of 12 different blankets and rescue bags commonly used by prehospital rescue and ambulance services. The thermal manikin and the selected insulation ensembles were setup inside a climatic chamber in accordance to the modified European Standard for assessing requirements of sleeping bags. Fans were adjusted to provide low (value, Itr (m2 C/Wclo; where C = degrees Celcius, and W = watts), was calculated from ambient air temperature (C), manikin surface temperature (C), and heat flux (W/m2). In the low wind condition, thermal insulation of the evaluated ensembles correlated to thickness of the ensembles, ranging from 2.0 to 6.0 clo (1 clo = 0.155 m2 C/W), except for the reflective metallic foil blankets that had higher values than expected. In moderate and high wind conditions, thermal insulation was best preserved for ensembles that were windproof and resistant to the compressive effect of the wind, with insulation reductions down to about 60-80% of the original insulation capacity, whereas wind permeable and/or lighter materials were reduced down to about 30-50% of original insulation capacity. The evaluated insulation ensembles might all be used for prehospital protection against cold, either as single blankets or in multiple layer combinations, depending on ambient temperatures. However, with extended

  5. Foam nests provide context-dependent thermal insulation to embryos of three leptodactylid frogs.

    Science.gov (United States)

    Méndez-Narváez, J; Flechas, S V; Amézquita, A

    2015-01-01

    The choice of adequate breeding habitat and its associated thermoregulatory conditions are thought to be important in the evolution of amphibian reproductive strategies. Among leptodactylid frogs, there is a terrestrial cline in the oviposition sites chosen to build foam nests for eggs. Although several functions have been attributed to foam nests, their role in temperature regulation for embryos is unclear. Here we tested the hypothesis that foam nests buffer embryos from variation in air temperature. We examined the degree of terrestrial nest sites in three species, finding a terrestrial cline of sites in terms of distance from water. We tested whether this nest-insulation effect varied among these species that differ in the degree of terrestrial nest sites and whether translocating nests impacted embryonic mortality. Our results demonstrate a negative effect of translocating aquatic nests to land, inferred from the highest hatching success in natural nests sites. All nests attenuated environmental thermal variation, but more terrestrial nests buffered embryos from a greater range of temperatures than did aquatic ones. Altogether, our data indicate that foam nests insulate embryos from daily temperature fluctuations among leptodactylid frogs with different degrees of terrestrial nests, which may well have contributed to the evolution of this reproductive strategy.

  6. A Novel Environmental Route to Ambient Pressure Dried Thermal Insulating Silica Aerogel via Recycled Coal Gangue

    Directory of Open Access Journals (Sweden)

    Pinghua Zhu

    2016-01-01

    Full Text Available Coal gangue, one of the main hazardous emissions of purifying coal from coalmine industry, is rich in silica and alumina. However, the recycling of the waste is normally restricted by less efficient techniques and low attractive output; the utilization of such waste is still staying lower than 15%. In this work, the silica aerogel materials were synthesized by using a precursor extracted from recycled silicon-rich coal gangue, followed by a single-step surface silylation and ambient pressure drying. A low density (~0.19 g/cm3 nanostructured aerogel with a 3D open porous microstructure and high surface area (~690 m2/g was synthesized, which presents a superior thermal insulation performance (~26.5 mW·m−1·K−1 of a plane packed of 4-5 mm granules which was confirmed by transient hot-wire method. This study offers a new facile route to the synthesis of insulating aerogel material by recycling solid waste coal gangue and presents a potential cost reduction of industrial production of silica aerogels.

  7. RELEVANT OBJECTIVES OF ASSURANCE OF RELIABILITY OF FACADE SYSTEMS SERVING THERMAL INSULATION AND FINISHING PURPOSES

    Directory of Open Access Journals (Sweden)

    Yavorskiy Andrey Andreevich

    2012-12-01

    Full Text Available The authors consider up-to-date methods of implementation of requirements stipulated by Federal Law no. 261-FZ that encompasses reduction of heat losses through installation of progressive heat-insulation systems, cement plaster system (CPS, and ventilated facades (VF. Unresolved problems of their efficient application caused by the absence of the all-Russian regulatory documents capable of controlling the processes of their installation and maintenance, as well as the projection of their behaviour, are also considered in the article. The authors argue that professional skills of designers and construction workers responsible for the design and installation of façade systems influence the quality and reliability of design and construction works. Unavailability of unified solutions or regulations serves as the objective reason for the unavailability of the respective database; therefore, there is an urgent need to perform a set of researches to have the unified database compiled. The authors use the example of thermal insulation cement plaster systems designated for facades as results of researches into the quantitative analysis of safety systems. Collected and systematized data that cover defects that have proven to be reasons for failures, as well as potential methods of their prevention are also studied. Data on pilot studies of major factors of influence onto reliability of glutinous adhesion of CPS to the base of a wall are provided.

  8. Determination of Optimum Thermal Insulation Thicknesses for External Walls Considering the Heating, Cooling and Annual Energy Requirement

    Directory of Open Access Journals (Sweden)

    Ömer KAYNAKLI

    2016-06-01

    Full Text Available In this study, optimization of thermal insulation thickness applied to the external walls of buildings has been carried out comparatively based on the seasonal (space-heating and cooling and the annual energy requirements considering solar radiation effect. This study has been performed for four degree-day regions of Turkey, namely, Iskenderun (in the first region, Istanbul (in the second region, Ankara (in the third region and Ardahan (in the fourth region. By determining the sol-air temperatures for each region and maximizing the present worth value of seasonal and annual energy savings, the optimum thermal insulation thicknesses have been calculated. The effects of solar radiation on heating-cooling energy requirements, the variation of optimum insulation thicknesses and payback periods with respect to degree-day regions, the differences between the analyses based on seasonal and annual have been presented in tabular and graphical form.

  9. Thermal insulation and confinement of plasma with a high-frequency electromagnetic field

    International Nuclear Information System (INIS)

    Vedenov, A.A.; Volkov, T.F.; Rudakov, L.I.; Sagdeyev, R.Z.; Glagolev, V.M.; Yeliseyev, G.A.; Khilil, V.V.

    1958-01-01

    At the Institute of Atomic Energy (Academy of Sciences, USSR) the problem of creating and thermally insulating plasma by means of high-frequency electromagnetic fields has been studied. Electromagnetic alternating fields which do not penetrate into plasma set up a pressure difference on the plasma boundary. There may be various ways of exciting alternating fields. One of the ways, most convenient from the radio engineering standpoint, is the setting up of a standing electromagnetic wave in a volume resonator partly filled with plasma. Such electromagnetic oscillations can be excited between the conductive walls of the resonator and the surface of plasma in such a way that the electromagnetic pressure, averaged over the high-frequency oscillations, with geometry specially selected, is the same at every point of the plasma surface

  10. A vacuum system for the thermal insulation of the SciFi distribution lines and manifolds

    CERN Document Server

    Joram, Christian

    2017-01-01

    This note describes some calculations and estimates for the layout, technology choice and performance of a vacuum system which shall ensure thermal insulation of the distribution lines and manifolds of the SiPM cooling system of the LHCb SciFi detector. We estimate the heat losses in concentric corrugated stainless steel pipes which leads to the conclusion that the pipes need to be evacuated to a pressure of about 1·10$^{-4}$ mbar. We then estimate the pumping conductance of the pipes and find that it will dominate over the effective pumping speed of any pump. We therefore conclude that a turbo molecular pump of small nominal pumping speed, which can easily achieve end pressures below 10$^{-5}$ mbar is adequate for this purpose. A preliminary layout of the vacuum system is being discussed at the end of the document.

  11. Fracture Toughness Evaluation of Space Shuttle External Tank Thermal Protection System Polyurethane Foam Insulation Materials

    Science.gov (United States)

    McGill, Preston; Wells, Doug; Morgan, Kristin

    2006-01-01

    Experimental evaluation of the basic fracture properties of Thermal Protection System (TPS) polyurethane foam insulation materials was conducted to validate the methodology used in estimating critical defect sizes in TPS applications on the Space Shuttle External Fuel Tank. The polyurethane foam found on the External Tank (ET) is manufactured by mixing liquid constituents and allowing them to react and expand upwards - a process which creates component cells that are generally elongated in the foam rise direction and gives rise to mechanical anisotropy. Similarly, the application of successive foam layers to the ET produces cohesive foam interfaces (knitlines) which may lead to local variations in mechanical properties. This study reports the fracture toughness of BX-265, NCFI 24-124, and PDL-1034 closed-cell polyurethane foam as a function of ambient and cryogenic temperatures and knitline/cellular orientation at ambient pressure.

  12. Response Surface Methodology for Design of Porous Hollow Sphere Thermal Insulator

    Science.gov (United States)

    Shohani, Nazanin; Pourmahdian, Saeed; Shirkavand Hadavand, Behzad

    2017-11-01

    In this study, response surface method is used for synthesizing polystyrene (PS) as sacrificial templates and optimizing the particle size. Three factors of initiator, stabilizer concentration and also stirring rate were selected as variable factors. Then, three different concentration of tetraethyl orthosilicate (TEOS) added to reaction media and core-shell structure with PS core and silica shell was developed. Finally, core-shell structure was changed to hollow silica sphere for using as thermal insulator. We observed that increased initiator concentration caused to larger PS particles, increase the stirring rate caused the smaller PS and also with increased the stabilizer concentration obtained that particle size decrease then after 2.5% began to increase. Also the optimum amount of TEOS was found.

  13. Thermal Insulation System Analysis Tool (TISTool) User's Manual. Version 1.0.0

    Science.gov (United States)

    Johnson, Wesley; Fesmire, James; Leucht, Kurt; Demko, Jonathan

    2010-01-01

    The Thermal Insulation System Analysis Tool (TISTool) was developed starting in 2004 by Jonathan Demko and James Fesmire. The first edition was written in Excel and Visual BasIc as macros. It included the basic shapes such as a flat plate, cylinder, dished head, and sphere. The data was from several KSC tests that were already in the public literature realm as well as data from NIST and other highly respectable sources. More recently, the tool has been updated with more test data from the Cryogenics Test Laboratory and the tank shape was added. Additionally, the tool was converted to FORTRAN 95 to allow for easier distribution of the material and tool. This document reviews the user instructions for the operation of this system.

  14. External Thermal Insulation Composite Systems: Critical Parameters for Surface Hygrothermal Behaviour

    Directory of Open Access Journals (Sweden)

    Eva Barreira

    2014-01-01

    Full Text Available External Thermal Insulation Composite Systems (ETICS are often used in Europe. Despite its thermal advantages, low cost, and ease of application, this system has serious problems of biological growth causing the cladding defacement. Recent studies pointed that biological growth is due to high values of surface moisture content, which mostly results from the combined effect of exterior surface condensation, wind-driven rain, and drying process. Based on numerical simulation, this paper points the most critical parameters involved in hygrothermal behaviour of ETICS, considering the influence of thermal and hygric properties of the external rendering, the effect of the characteristics of the façade, and the consequences of the exterior and interior climate on exterior surface condensation, wind-driven rain, and drying process. The model used was previously validated by comparison with the results of an “in situ” campaign. The results of the sensitivity analyses show that relative humidity and temperature of the exterior air, atmospheric radiation, and emissivity of the exterior rendering are the parameters that most influence exterior surface condensation. Wind-driven rain depends mostly on horizontal rain, building’s height, wind velocity, and orientation. The drying capacity is influenced by short-wave absorbance, incident solar radiation, and orientation.

  15. Guar gum benzoate nanoparticle reinforced gelatin films for enhanced thermal insulation, mechanical and antimicrobial properties.

    Science.gov (United States)

    Kundu, Sonia; Das, Aatrayee; Basu, Aalok; Abdullah, Md Farooque; Mukherjee, Arup

    2017-08-15

    This work relates to guar gum benzoate self assembly nanoparticles synthesis and nano composite films development with gelatin. Guar gum benzoate was synthesized in a Hofmeister cation guided homogeneous phase reaction. Self assembly polysaccharide nanoparticles were prepared in solvent displacement technique. Electron microscopy and DLS study confirmed uniform quasi spherical nanoparticles with ζ-potential - 28.7mV. Nanocomposite films were further developed in gelatin matrix. The film capacity augmenting due to nanoparticles incorporation was noteworthy. Superior barrier properties, reinforcing and thermal insulation effects were observed in films dispersed with 20% w/w nanoparticles. Detailed FTIR studies and thermal analysis confirmed nanoparticles interactions in the film matrix. The nanocomposite film water vapour permeability was at 0.75gmm -1 kPa -1 h -1 , thermal conductivity 0.39Wm -1 K -1 and the tensile strength were recorded at 3.87MPa. The final film expressed excellent antimicrobial properties against water born gram negative and gram positive bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Micro thermal diode with glass thermal insulation structure embedded in a vapor chamber

    Science.gov (United States)

    Tsukamoto, Takashiro; Hirayanagi, Takashi; Tanaka, Shuji

    2017-04-01

    This paper reports a micro thermal diode based on one-way working fluid circulation driven by surface tension force. In forward mode, working fluid evaporates and condenses at a heated and cooled area, respectively, and the condensed liquid returns to the evaporation area due to the wettability difference. By this vapor-liquid phase change mechanism, the overall heat transfer coefficient becomes high. On the other hand, in reverse mode, no continuous evaporation-condensation cycle exists. The conductive heat loss in reverse mode was minimized by an embedded glass thermal isolation structure, which makes overall heat transfer coefficient low. The test device was made by a standard MEMS process combined with glass reflow and gold bump sealing. The overall heat transfer coefficients of 13 300 \\text{W}~{{\\text{m}}-2}~\\text{K} for forward mode and 4790 \\text{W}~{{\\text{m}}-2}~\\text{K} for reverse mode were measured. The performance index of the micro thermal diode was about 2.8.

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

    DEFF Research Database (Denmark)

    Rose, Jørgen; Svendsen, Svend

    2005-01-01

    be quite tedious, and therefore a method to generate and optimize solutions has been developed and implemented in a program that also takes into account the effects of different types of thermal bridges, i.e. roof windows, insulation fasteners, roof/wall joints etc. This paper describes a new method...

  18. A Study on Variation of Thermal Characteristics of Insulation Materials for Buildings According to Actual Long-Term Annual Aging Variation

    Science.gov (United States)

    Choi, Hyun-Jung; Kang, Jae-Sik; Huh, Jung-Ho

    2018-01-01

    Insulation materials used for buildings are broadly classified as organic insulation materials or inorganic insulation materials. Foam gas is used for producing organic insulation materials. The thermal conductivity of foam gas is generally lower than that of air. As a result, foam gas is discharged over time and replaced by outside air that has relatively less thermal resistance. The gas composition ratio in air bubbles inside the insulation materials changes rapidly, causing the performance degradation of insulation materials. Such performance degradation can be classified into different stages. Stage 1 appears to have a duration of 5 years, and Stage 2 takes a period of over 10 years. In this study, two insulation materials that are most frequently used in South Korea were analyzed, focusing on the changes thermal resistance for the period of over 5000 days. The measurement result indicated that the thermal resistance of expanded polystyrene fell below the KS performance standards after about 80-150 days from its production date. After about 5000 days, its thermal resistance decreased by 25.7 % to 42.7 % in comparison with the initial thermal resistance. In the case of rigid polyurethane, a pattern of rapid performance degradation appeared about 100 days post-production, and the thermal resistance fell below the KS performance standards after about 1000 days. The thermal resistance decreased by 22.5 % to 27.4 % in comparison with the initial thermal resistance after about 5000 days.

  19. Thermal barrier coatings for thermal insulation and corrosion resistance in industrial gas turbine engines

    Science.gov (United States)

    Vogan, J. W.; Hsu, L.; Stetson, A. R.

    1981-01-01

    Four thermal barrier coatings were subjected to a 500-hour gas turbine engine test. The coatings were two yttria stabilized zirconias, calcium ortho silicate and calcium meta titanate. The calcium silicate coating exhibited significant spalling. Yttria stabilized zirconia and calcium titanate coatings showed little degradation except in blade leading edge areas. Post-test examination showed variations in the coating due to manual application techniques. Improved process control is required if engineering quality coatings are to be developed. The results indicate that some leading edge loss of the coating can be expected near the tip.

  20. Reducing heat stress under thermal insulation in protective clothing: microclimate cooling by a 'physiological' method.

    Science.gov (United States)

    Glitz, K J; Seibel, U; Rohde, U; Gorges, W; Witzki, A; Piekarski, C; Leyk, D

    2015-01-01

    Heat stress caused by protective clothing limits work time. Performance improvement of a microclimate cooling method that enhances evaporative and to a minor extent convective heat loss was tested. Ten male volunteers in protective overalls completed a work-rest schedule (130 min; treadmill: 3 × 30 min, 3 km/h, 5% incline) with or without an additional air-diffusing garment (climatic chamber: 25°C, 50% RH, 0.2 m/s wind). Heat loss was supported by ventilating the garment with dry air (600 l/min, ≪5% RH, 25°C). Ventilation leads (M ± SD, n = 10, ventilated vs. non-ventilated) to substantial strain reduction (max. HR: 123 ± 12 b/min vs. 149 ± 24 b/min) by thermal relief (max. core temperature: 37.8 ± 0.3°C vs. 38.4 ± 0.4°C, max. mean skin temperature: 34.7 ± 0.8°C vs. 37.1 ± 0.3°C) and offers essential extensions in performance and work time under thermal insulation. Heat stress caused by protective clothing limits work time. Performance can be improved by a microclimate cooling method that supports evaporative and to a minor extent convective heat loss. Sweat evaporation is the most effective thermoregulatory mechanism for heat dissipation and can be enhanced by insufflating dry air into clothing.

  1. Influence of iron on crystallization behavior and thermal stability of the insulating materials - porous calcium silicates

    DEFF Research Database (Denmark)

    Haastrup, Sonja; Yu, Donghong; Yue, Yuanzheng

    2017-01-01

    The properties of porous calcium silicate for high temperature insulation are strongly influenced by impurities. In this work we determine the influence of Fe3+ on the crystallization behavior and thermal stability of hydrothermally derived calcium silicate. We synthesize porous calcium silicate...... by XRD analysis. The thermal stability and compressive strength of the calcium silicates are seriously influenced by the changes of their crystal structure. Linear shrinkage of the reference sample is 1.3% at 1050°C, whereas the sample with Fe/Si =1.0% does by 30.4%. In conclusion, the presence of Fe3...... measurements reveal a pronounced decrease in the number of Q3 sites in the calcium silicate with an increase of Fe3+, and thereby lower the crystal fraction of xonotlite (Ca6Si6O17(OH)2) phase, and increase the crystal fractions of tobermorite(Ca5Si6O16(OH)2·4H2O) and calcite (CaCO3) phases, as confirmed...

  2. Response to fire, thermal insulation and acoustic performance of rigid polyurethane agglomerates with addition of natural fiber

    Directory of Open Access Journals (Sweden)

    Marcos Vinicius Rizzo

    2015-03-01

    Full Text Available This paper aims to reuse rigid polyurethane waste in the preparation of composites with the addition of banana fibers and cellulose in order to qualify the acoustic performance, thermal insulation and reaction to fire the material with the addition of 7% of polysulfone. Agglomerated with 100% of polyurethane and either with 20% of banana fiber or 20% of cellulose were characterized in the sound transmission loss, thermal conductivity and reaction to fire, take into account variations in the granulometry of the solid polyurethane and type of pressing. Natural fiber composites had lower thermal conductivity, higher acoustic insulation in medium frequencies and the addition of polysulfone delayed the total time of firing the material.

  3. Thermal performance measurements of a 100 percent polyester MLI [multilayer insulation] system for the Superconducting Super Collider

    International Nuclear Information System (INIS)

    Gonczy, J.D.; Boroski, W.N.; Niemann, R.C.

    1989-09-01

    The plastic materials used in the multilayer insulation (MLI) blankets of the superconducting magnets of the Superconducting Super Collider (SSC) are comprised entirely of polyesters. This paper reports on tests conducted in three separate experimental blanket arrangements. The tests explore the thermal performance of two candidate blanket joint configurations each employing a variation of a stepped-butted joint nested between sewn blanket seams. The results from the joint configurations are compared to measurements made describing the thermal performance of the basic blanket materials as tested in an ideal joint configuration. Twenty foil sensors were incorporated within each test blanket to measure interstitial layer and joint layer temperatures. Heat flux and thermal gradients are reported for high and degraded insulating vacuums, and during transient and steady state conditions. In complement with this paper is an associate paper bearing the same title head but with the title extension 'Part 1: Instrumentation and experimental preparation (300K-80K)'. 5 refs., 8 figs., 2 tabs

  4. Thermal Modeling of the Injection of Standard and Thermally Insulated Cored Wire

    Science.gov (United States)

    Castro-Cedeno, E.-I.; Jardy, A.; Carré, A.; Gerardin, S.; Bellot, J. P.

    2017-12-01

    Cored wire injection is a widespread method used to perform alloying additions during ferrous and non-ferrous liquid metal treatment. The wire consists of a metal casing that is tightly wrapped around a core of material; the casing delays the release of the material as the wire is immersed into the melt. This method of addition presents advantages such as higher repeatability and yield of cored material with respect to bulk additions. Experimental and numerical work has been performed by several authors on the subject of alloy additions, spherical and cylindrical geometries being mainly considered. Surprisingly this has not been the case for cored wire, where the reported experimental or numerical studies are scarce. This work presents a 1-D finite volume numerical model aimed for the simulation of the thermal phenomena which occurs when the wire is injected into a liquid metal bath. It is currently being used as a design tool for the conception of new types of cored wire. A parametric study on the effect of injection velocity and steel casing thickness for an Al cored wire immersed into a steel melt at 1863 K (1590 °C) is presented. The standard single casing wire is further compared against a wire with multiple casings. Numerical results show that over a certain range of injection velocities, the core contents' release is delayed in the multiple casing when compared to a single casing wire.

  5. Survey and evaluation of available thermal insulation materials for use on solar heating and cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    1980-03-01

    This is the final report of a survey and evaluation of insulation materials for use with components of solar heating and cooling systems. The survey was performed by mailing questionnaires to manufacturers of insulation materials and by conducting an extensive literature search to obtain data on relevant properties of various types of insulation materials. The study evaluated insulation materials for active and passive solar heating and cooling systems and for multifunction applications. Primary and secondary considerations for selecting insulation materials for various components of solar heating and cooling systems are presented.

  6. Thermal implications of interactions between insulation, solar reflectance, and fur structure in the summer coats of diverse species of kangaroo.

    Science.gov (United States)

    Dawson, Terence J; Maloney, Shane K

    2017-04-01

    Not all of the solar radiation that impinges on a mammalian coat is absorbed and converted into thermal energy at the coat surface. Some is reflected back to the environment, while another portion is reflected further into the coat where it is absorbed and manifested as heat at differing levels. Substantial insulation in a coat limits the thermal impact at the skin of solar radiation, irrespective where in the coat it is absorbed. In coats with low insulation, the zone where solar radiation is absorbed may govern the consequent heat load on the skin (HL-SR). Thin summer furs of four species of kangaroo from differing climatic zones were used to determine how variation in insulation and in coat spectral and structural characteristics influence the HL-SR. Coat depth, structure, and solar reflectance varied between body regions, as well as between species. The modulation of solar radiation and resultant heat flows in these coats were measured at low (1 m s -1 ) and high (6 m s -1 ) wind speeds by mounting them on a heat flux transducer/temperature-controlled plate apparatus in a wind tunnel. A lamp with a spectrum similar to solar radiation was used as a proxy for the sun. We established that coat insulation was largely determined by coat depth at natural fur lie, despite large variations in fibre density, fibre diameter, and fur mass. Higher wind speed decreased coat insulation, but depth still determined the overall level. A multiple regression analysis that included coat depth (insulation), fibre diameter, fibre density, and solar reflectance was used to determine the best predictors of HL-SR. Only depth and reflectance had significant impacts and both factors had negative weights, so, as either insulation or reflectance increased, HL-SR declined, the larger impact coming from coat reflectance. This reverses the pattern observed in deep coats where insulation dominates over effects of reflectance. Across all coats, as insulation declined, reflectance increased

  7. Optimum interior area thermal resistance model to analyze the heat transfer characteristics of an insulated pipe with arbitrary shape

    International Nuclear Information System (INIS)

    Chou, H.-M.

    2003-01-01

    The heat transfer characteristics for an insulated regular polygonal (or circular) pipe are investigated by using a wedge thermal resistance model as well as the interior area thermal resistance model R th =t/K s /[(1-α)A 2 +αA 3 ] with a surface area weighting factor α. The errors of the results generated by an interior area model can be obtained by comparing with the exact results generated by a wedge model. Accurate heat transfer rates can be obtained without error at the optimum α opt with the related t/R 2 . The relation between α opt and t/R 2 is α opt =1/ln(1+t/R 2 )-1/(t/R 2 ). The value of α opt is greater than zero and less than 0.5 and is independent of pipe size R 2 /R cr but strongly dependent on the insulation thickness t/R 2 . The interior area model using the optimum value α opt with the related t/R 2 should also be applied to an insulated pipe with arbitrary shape within a very small amount of error for the results of heat transfer rates. The parameter R 2 conservatively corresponds to the outside radius of the maximum inside tangent circular pipe within the arbitrary shaped pipes. The approximate dimensionless critical thickness t cr /R 2 and neutral thickness t e /R 2 of an insulated pipe with arbitrary shape are also obtained. The accuracies of the value of t cr /R 2 as well as t e /R 2 are strongly dependent on the shape of the insulated small pipe. The closer the shape of an insulated pipe is to a regular polygonal or circular pipe, the more reliable will the values of t cr /R 2 as well as t e /R 2 be

  8. Thermal transport in topological-insulator-based superconducting hybrid structures with mixed singlet and triplet pairing states.

    Science.gov (United States)

    Li, Hai; Zhao, Yuan Yuan

    2017-11-22

    In the framework of the Bogoliubov-de Gennes equation, we investigate the thermal transport properties in topological-insulator-based superconducting hybrid structures with mixed spin-singlet and spin-triplet pairing states, and emphasize the different manifestations of the spin-singlet and spin-triplet pairing states in the thermal transport signatures. It is revealed that the temperature-dependent differential thermal conductance strongly depends on the components of the pairing state, and the negative differential thermal conductance only occurs in the spin-singlet pairing state dominated regime. It is also found that the thermal conductance is profoundly sensitive to the components of the pairing state. In the spin-singlet pairing state controlled regime, the thermal conductance obviously oscillates with the phase difference and junction length. With increasing the proportion of the spin-triplet pairing state, the oscillating characteristic of the thermal conductance fades out distinctly. These results suggest an alternative route for distinguishing the components of pairing states in topological-insulator-based superconducting hybrid structures.

  9. Study of the Impact of Initial Moisture Content in Oil Impregnated Insulation Paper on Thermal Aging Rate of Condenser Bushing

    Directory of Open Access Journals (Sweden)

    Youyuan Wang

    2015-12-01

    Full Text Available This paper studied the impact of moisture on the correlated characteristics of the condenser bushings oil-paper insulation system. The oil-impregnated paper samples underwent accelerated thermal aging at 130 °C after preparation at different initial moisture contents (1%, 3%, 5% and 7%. All the samples were extracted periodically for the measurement of the moisture content, the degree of polymerization (DP and frequency domain dielectric spectroscopy (FDS. Next, the measurement results of samples were compared to the related research results of transformer oil-paper insulation, offering a theoretical basis of the parameter analysis. The obtained results show that the moisture fluctuation amplitude can reflect the different initial moisture contents of insulating paper and the mass ratio of oil and paper has little impact on the moisture content fluctuation pattern in oil-paper but has a great impact on moisture fluctuation amplitude; reduction of DP presents an accelerating trend with the increase of initial moisture content, and the aging rate of test samples is higher under low moisture content but lower under high moisture content compared to the insulation paper in transformers. Two obvious “deceleration zones” appeared in the dielectric spectrum with the decrease of frequency, and not only does the integral value of dielectric dissipation factor (tan δ reflect the aging degree, but it reflects the moisture content in solid insulation. These types of research in this paper can be applied to evaluate the condition of humidified insulation and the aging state of solid insulation for condenser bushings.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  11. Standard Test Method for Oxyacetylene Ablation Testing of Thermal Insulation Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method covers the screening of ablative materials to determine the relative thermal insulation effectiveness when tested as a flat panel in an environment of a steady flow of hot gas provided by an oxyacetylene burner. 1.2 This test method should be used to measure and describe the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard of materials, products, or assemblies under actual fire conditions. However, results of this test method may be used as elements of a fire risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of a particular end use. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limi...

  12. Experimental Study of Fire Hazards of Thermal-Insulation Material in Diesel Locomotive: Aluminum-Polyurethane

    Science.gov (United States)

    Zhang, Taolin; Zhou, Xiaodong; Yang, Lizhong

    2016-01-01

    This work investigated experimentally and theoretically the fire hazards of thermal-insulation materials used in diesel locomotives under different radiation heat fluxes. Based on the experimental results, the critical heat flux for ignition was determined to be 6.15 kW/m2 and 16.39 kW/m2 for pure polyurethane and aluminum-polyurethane respectively. A theoretical model was established for both to predict the fire behaviors under different circumstances. The fire behavior of the materials was evaluated based on the flashover and the total heat release rate (HRR). The fire hazards levels were classified based on different experimental results. It was found that the fire resistance performance of aluminum-polyurethane is much better than that of pure-polyurethane under various external heat fluxes. The concentration of toxic pyrolysis volatiles generated from aluminum-polyurethane materials is much higher than that of pure polyurethane materials, especially when the heat flux is below 50 kW/m2. The hazard index HI during peak width time was proposed based on the comprehensive impact of time and concentrations. The predicted HI in this model coincides with the existed N-gas and FED models which are generally used to evaluate the fire gas hazard in previous researches. The integrated model named HNF was proposed as well to estimate the fire hazards of materials by interpolation and weighted average calculation. PMID:28773295

  13. Multilayered thermal insulation formed of zirconia bonded layers of zirconia fibers and metal oxide fibers and method for making same

    Science.gov (United States)

    Wrenn, Jr., George E.; Holcombe, Jr., Cressie E.

    1988-01-01

    A multilayered thermal insulating composite is formed of a first layer of zirconia-bonded zirconia fibers for utilization near the hot phase or surface of a furnace or the like. A second layer of zirconia-bonded metal oxide fibers is attached to the zirconia fiber layer by a transition layer formed of intermingled zirconia fibers and metal oxide fibers. The thermal insulation is fabricated by vacuum molding with the layers being sequentially applied from aqueous solutions containing the fibers to a configured mandrel. A portion of the solution containing the fibers forming the first layer is intermixed with the solution containing the fibers of the second layer for forming the layer of mixed fibers. The two layers of fibers joined together by the transition layer are saturated with a solution of zirconium oxynitrate which provides a zirconia matrix for the composite when the fibers are sintered together at their nexi.

  14. Fabrication of Ohmic contact on semi-insulating 4H-SiC substrate by laser thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yue; Lu, Wu-yue; Wang, Tao; Chen, Zhi-zhan, E-mail: zzchen@shnu.edu.cn [Department of Physics, Shanghai Normal University, 100 Guilin Road, Shanghai 200234 (China)

    2016-06-14

    The Ni contact layer was deposited on semi-insulating 4H-SiC substrate by magnetron sputtering. The as-deposited samples were treated by rapid thermal annealing (RTA) and KrF excimer laser thermal annealing (LTA), respectively. The RTA annealed sample is rectifying while the LTA sample is Ohmic. The specific contact resistance (ρ{sub c}) is 1.97 × 10{sup −3} Ω·cm{sup 2}, which was determined by the circular transmission line model. High resolution transmission electron microscopy morphologies and selected area electron diffraction patterns demonstrate that the 3C-SiC transition zone is formed in the near-interface region of the SiC after the as-deposited sample is treated by LTA, which is responsible for the Ohmic contact formation in the semi-insulating 4H-SiC.

  15. Effect of Thermal Bridges in Insulated Walls on Air-Conditioning Loads Using Whole Building Energy Analysis

    Directory of Open Access Journals (Sweden)

    Mohamed F. Zedan

    2016-06-01

    Full Text Available Thermal bridges in building walls are usually caused by mortar joints between insulated building blocks and by the presence of concrete columns and beams within the building envelope. These bridges create an easy path for heat transmission and therefore increase air-conditioning loads. In this study, the effects of mortar joints only on cooling and heating loads in a typical two-story villa in Riyadh are investigated using whole building energy analysis. All loads found in the villa, which broadly include ventilation, transmission, solar and internal loads, are considered with schedules based on local lifestyles. The thermal bridging effect of mortar joints is simulated by reducing wall thermal resistance by a percentage that depends on the bridges to wall area ratio (TB area ratio or Amj/Atot and the nominal thermal insulation thickness (Lins. These percentage reductions are obtained from a correlation developed by using a rigorous 2D dynamic model of heat transmission through walls with mortar joints. The reduction in thermal resistance is achieved through minor reductions in insulation thickness, thereby keeping the thermal mass of the wall essentially unchanged. Results indicate that yearly and monthly cooling loads increase almost linearly with the thermal bridge to wall area ratio. The increase in the villa’s yearly loads varies from about 3% for Amj/Atot = 0.02 to about 11% for Amj/Atot = 0.08. The monthly increase is not uniform over the year and reaches a maximum in August, where it ranges from 5% for Amj/Atot = 0.02 to 15% for Amj/Atot = 0.08. In winter, results show that yearly heating loads are generally very small compared to cooling loads and that heating is only needed in December, January and February, starting from late night to late morning. Monthly heating loads increase with the thermal bridge area ratio; however, the variation is not as linear as observed in cooling loads. The present results highlight the importance of

  16. Evaluation of the application of a thermal insulation system: in-situ comparison of seasonal and daily climatic fluctuations

    Czech Academy of Sciences Publication Activity Database

    Fořt, J.; Beran, Pavel; Konvalinka, P.; Pavlík, Z.; Černý, R.

    2017-01-01

    Roč. 57, č. 3 (2017), s. 159-166 ISSN 1210-2709 R&D Projects: GA ČR(CZ) GBP105/12/G059 Institutional support: RVO:68378297 Keywords : in-situ monitoring * temperature * relative humidity * thermal insulation * energy sustainability * seasonal fluctuations Subject RIV: JN - Civil Engineering OBOR OECD: Construction engineering, Municipal and structural engineering https://ojs.cvut.cz/ojs/ index .php/ap/article/view/4087/4171

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

    OpenAIRE

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

    2015-01-01

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

  18. Ultralight, highly thermally insulating and fire resistant aerogel by encapsulating cellulose nanofibers with two-dimensional MoS2.

    Science.gov (United States)

    Yang, Lei; Mukhopadhyay, Alolika; Jiao, Yucong; Yong, Qiang; Chen, Liao; Xing, Yingjie; Hamel, Jonathan; Zhu, Hongli

    2017-08-17

    Thermally insulating materials, made from earth-abundant and sustainable resources, are highly desirable in the sustainable construction of energy efficient buildings. Cellulose from wood has long been recognized for these characteristics. However, cellulose can be a flammability hazard, and for construction this has been addressed via chemical treatment such as that with halogen and/or phosphorus, which leads to further environmental concerns. Fortunately, the structure of cellulose lends itself well to chemical modification, giving great potential to explore interaction with other compounds. Thus, in this study, cellulose nanofibers (CNFs) were nano-wrapped with ultrathin 1T phase molybdenum disulfide (MoS 2 ) nanosheets via chemical crosslinking, to produce an aerogel. Thermal and combustion characterization revealed highly desirable properties (thermal conductivity k = 28.09 mW m -1 K -1 , insulation R value = 5.2, limit oxygen index (LOI) = 34.7%, total heat release = 0.4 MJ m -2 ). Vertical burning tests also demonstrated excellent fire retardant and self-extinguishing capabilities. Raman spectra further revealed that MoS 2 remained unscathed after 30 seconds of burning in a 1300 °C butane flame. Considering the inherently low density of this material, there is significant opportunity for its usage in a number of insulating applications demanding specific fire resistance properties.

  19. Multi-criteria thermal evaluation of wall enclosures of high-rise buildings insulated products based on modified fibers

    Science.gov (United States)

    Pavlov, Alexey; Pavlova, Larisa; Pavlova, Lyudmila

    2018-03-01

    In article results of research of versions of offered types of heaters on the basis of products from the modified fibers for designing energy efficient building enclosures residential high-rise buildings are presented. Traditional building materials (reinforced concrete, brick, wood) are not able to provide the required value of thermal resistance in areas with a temperate and harsh Russia climate in a single-layered enclosing structure. It can be achieved in a multi-layered enclosing structure, where the decisive role is played by new insulating materials with high thermal properties. In general, modern design solutions for external walls are based on the use of new effective thermal insulation materials with the use of the latest technology. The relevance of the proposed topic is to research thermoinsulation properties of new mineral heaters. Theoretical researches of offered heaters from mineral wool on slime-colloidal binder, bentocolloid and microdispersed binders are carried out. In addition, theoretical studies were carried out with several types of facade systems. Comprehensive studies were conducted on the resistance to heat transfer, resistance to vapor permeation and air permeability. According to the received data, recommendations on the use of insulation types depending on the number of storeys of buildings are proposed.

  20. Determination of Thermal Transmittance of Insulated Double Low-E Glazing Panel Using Portable Uglass Measuring Technique

    Science.gov (United States)

    Kim, Inkoo; Frenzl, Alexander; Kim, Taehan; Min, Steven; Blumm, Jürgen

    2018-01-01

    Windows are regarded as the primary object of energy efficiency in buildings because window is one of the major energy loss areas in building construction. Existing methods were not field measurements and were not enough to get the correct thermal transmittance. We used portable Ug measuring device on field and measured the thermal transmittance with low-E coated and uncoated double glazing panels in existing houses, apartments and buildings. In addition, we prepared four test benches and compared the insulation performance according to the construction conditions. In results, the insulation performance of double glazing panel with low-E coating is up to about 41 % higher than uncoated panel due to low-E coating inside and the glazing panel filled with about 90 % of argon gas decrease about 0.15 W \\cdot m^{-2} \\cdot K^{-1} than glazing panel filled with air gas. The measured results were compared with the theoretically calculated results according to DIN EN 673 to confirm the reliability of the analytical results. In this study, portable NETZSCH Uglass is used to increase the accuracy of calculation of thermal transmittance with various double and triple glazing panels. The paper analyzes the insulation performance of the double glazing panels in accordance with the construction conditions.

  1. Carbon footprint of a reflective foil and comparison with other solutions for thermal insulation in building envelope

    International Nuclear Information System (INIS)

    Proietti, Stefania; Desideri, Umberto; Sdringola, Paolo; Zepparelli, Francesco

    2013-01-01

    Highlights: ► Environmental and energy assessment of thermal insulating materials in building envelope. ► Carbon footprint of a reflective foil, conceived and produced by an Italian company. ► Study conducted according to principles of LCA – Life Cycle Assessment. ► Identification of main impacting processes and measures for reducing emissions. ► Comparison with traditional insulating materials (EPS and rockwool). - Abstract: The present study aims at assessing environmental and energy compatibility of different solutions of thermal insulation in building envelope. In fact a good insulation results in a reduction of heating/cooling energy consumptions; on the other hand construction materials undergo production, transformation and transport processes, whose energy and resources consumptions may lead to a significant decrease of the environmental benefits. The paper presents a detailed carbon footprint of a product (CFP, defined as the sum of greenhouse gas emissions and removals of a product system, expressed in CO 2 equivalents), which is a reflective foil conceived and produced by an Italian company. CFP can be seen as a Life Cycle Assessment with climate change as the single impact category; it does not assess other potential social, economic and environmental impacts arising from the provision of products. The analysis considers all stages of the life cycle, from the extraction of raw materials to the product’s disposal, i.e. “from cradle to grave”; it was carried out according to UNI EN ISO 14040 and 14044, and LCA modelling was performed using SimaPro software tool. On the basis of obtained results, different measures have been proposed in order to reduce emissions in the life cycle and neutralize residual carbon footprint. The results allowed to make an important comparison concerning the environmental performance of the reflective foil in comparison with other types of insulating materials

  2. Improving Thermal Insulation Properties for Prefabricated Wall Components Made Of Lightweight Aggregate Concrete with Open Structure

    Science.gov (United States)

    Abramski, Marcin

    2017-10-01

    Porous concrete is commonly used in civil engineering due to its good thermal insulation properties in comparison with normal concrete and high compression strength in comparison with other building materials. Reducing of the concrete density can be obviously obtained by using lightweight aggregate (e.g. pumice). The concrete density can be further minimized by using specially graded coarse aggregate and little-to-no fine aggregates. In this way a large number of air voids arise. The aggregate particles are coated by a cement paste and bonded together with it just in contact points. Such an extremely porous concrete, called ‘lightweight aggregate concrete with open structure’ (LAC), is used in some German plants to produce prefabricated wall components. They are used mainly in hall buildings, e.g. supermarkets. The need of improving thermal insulation properties was an inspiration for the prefabrication plant managers, engineers and a scientific staff of the Technical University of Kaiserslautern / Germany to realise an interesting project. Its aim was to reduce the heat transfer coefficient for the wall components. Three different wall structure types were designed and compared in full-scale laboratory tests with originally produced wall components in terms of load-carrying capacity and stiffness. The load was applied perpendicularly to the wall plane. As the components are not originally used for load-bearing walls, but for curtain walls only, the wind load is the main load for them. The wall components were tested in horizontal position and the load was applied vertically. Totally twelve wall components 8.00 × 2.00 × 0.25m (three for every series) were produced in the prefabrication plant and tested in the University of Kaiserslautern laboratory. The designed and tested components differed from each other in the amount of expanded polystyrene (EPS), which was placed in the plant inside the wall structure. The minimal amount of it was designed in the

  3. Colloquium 3: Thermal insulation materials in construction and in high-temperature plants. Lectures; Kolloquium 3: Waermedaemmstoffe im Bauwesen und in Hochtemperaturanlagen. Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, E.; Gross, U.; Walter, G. [comps.

    1999-07-01

    Colloquium 3, ''Thermal insulation materials in construction and in high-temperature plants'' focused, for one thing, on the inter-relationships between the development of thermal insulation materials for construction and high-temperature applications and the development of processes and plants and, for another, on the standards of and amendments to the thermal protection ordinance. Calcium silicate and Silcapor as a thermal protection material and a high-temperature thermal insulant, respectively, are dealt with inter alia. The use of thermal insulants in industrial furnaces and different methods for measuring thermal conductivity are described. Further topics are the elements of the energy conservation ordinance being drafted, and thermal-insulation construction materials such as bricks and foam mortar. Ten papers are individually listed in the Energy database. (orig.) [German] Im Mittelpunkt des Kolloquium 3 ''Waermedaemmstoffe im Bauwesen und in Hochtemperaturanlagen'' stehen die wechselseitigen Zusammenhaenge zwischen der Entwicklung von Waermedaemmstoffen fuer das Bauwesen und die Hochtemperaturanwendung einerseits und der Prozess-und Anlagenentwicklung anderseits sowie die Normung und die Novellierung der Waermeschutzverordnung. Es wird u.a. auf den Waermedaemmstoff Calciumsilicat eingegangen ebensowie auf Silcapor als Hochtemperaturd ammstoff. Der Einsatz von Waermedaemmstoffen in Industrieoefen sowie die unterschiedlichen Messmethoden der Waermeleitfaehigkeit werden beschrieben. Weitere Themen sind die Grundlagen der kuenftigen Energiesparverordnung sowie waermedaemmende Baustoffe wie Ziegel und Porenbeton. Fuer die Datenbank Energy wurden zehn Arbeiten separat aufgenommen.

  4. Thermally driven magnon transport in the magnetic insulator Yttrium Iron Garnet

    International Nuclear Information System (INIS)

    Agrawal, Milan

    2014-01-01

    The research work presented in this thesis covers the investigation of spin-caloric phenomena in ferromagnetic-normal metal heterostructures. These phenomena explore the interaction of heat with spin systems and mainly deal with the generation and the manipulation of spin currents by means of heat currents (phonons). The significance of spin currents is widely seen in developing new fundamental concepts of physics as well as in the industry of magnetic memories. Analogous to the classical Seebeck effect, the generation of a spin current in a spin system by the application of heat currents is known as the spin Seebeck effect (SSE). This mode of spin current generation has recently attracted much scientific attention due to the existence of the spin Seebeck effect in a wide variety of magnetic materials (spin systems), considering from insulators to metals. The potential applications of this effect, in particular to generate electricity out of waste heat, make the effect even more attractive. Generally, spin systems can be classified into either a system constituting the traveling spins carried by free electrons or into a system of spin waves, collective excitations of magnetic moments in the wavevector space. Having the advantage of being free from free-electronic charges, an electrical-insulating-ferromagnetic system of spin waves overcomes the limitation of short propagation lengths of pure spin currents in metals. The long propagation length of spin currents carried by propagating spin waves is crucial for building-up spin-electronic (spintronic) circuits and spin logics for fast computation. For such purposes, the ferrimagnetic insulator Yttrium Iron Garnet (YIG) is a promising material candidate due to its lowest known magnetic damping which offers macroscopic propagation lengths of spin currents. In the framework of this thesis, a detailed investigation of the interaction of phonons with magnons, the quanta of spin waves, in single crystalline YIG films are

  5. Stochastic IMT (Insulator-Metal-Transition Neurons: An Interplay of Thermal and Threshold Noise at Bifurcation

    Directory of Open Access Journals (Sweden)

    Abhinav Parihar

    2018-04-01

    Full Text Available Artificial neural networks can harness stochasticity in multiple ways to enable a vast class of computationally powerful models. Boltzmann machines and other stochastic neural networks have been shown to outperform their deterministic counterparts by allowing dynamical systems to escape local energy minima. Electronic implementation of such stochastic networks is currently limited to addition of algorithmic noise to digital machines which is inherently inefficient; albeit recent efforts to harness physical noise in devices for stochasticity have shown promise. To succeed in fabricating electronic neuromorphic networks we need experimental evidence of devices with measurable and controllable stochasticity which is complemented with the development of reliable statistical models of such observed stochasticity. Current research literature has sparse evidence of the former and a complete lack of the latter. This motivates the current article where we demonstrate a stochastic neuron using an insulator-metal-transition (IMT device, based on electrically induced phase-transition, in series with a tunable resistance. We show that an IMT neuron has dynamics similar to a piecewise linear FitzHugh-Nagumo (FHN neuron and incorporates all characteristics of a spiking neuron in the device phenomena. We experimentally demonstrate spontaneous stochastic spiking along with electrically controllable firing probabilities using Vanadium Dioxide (VO2 based IMT neurons which show a sigmoid-like transfer function. The stochastic spiking is explained by two noise sources - thermal noise and threshold fluctuations, which act as precursors of bifurcation. As such, the IMT neuron is modeled as an Ornstein-Uhlenbeck (OU process with a fluctuating boundary resulting in transfer curves that closely match experiments. The moments of interspike intervals are calculated analytically by extending the first-passage-time (FPT models for Ornstein-Uhlenbeck (OU process to include a

  6. Fourier Transform Infrared (FTIR Spectroscopy Analysis of Transformer Paper in Mineral Oil-Paper Composite Insulation under Accelerated Thermal Aging

    Directory of Open Access Journals (Sweden)

    Abi Munajad

    2018-02-01

    Full Text Available Mineral oil is the most popular insulating liquid for high voltage transformers due to its function as a cooling liquid and an electrical insulator. Kraft paper has been widely used as transformer solid insulation for a long time already. The degradation process of transformer paper due to thermal aging in mineral oil can change the physical and chemical structure of the cellulose paper. Fourier transform infrared (FTIR spectroscopy analysis was used to identify changes in the chemical structure of transformer paper aged in mineral oil. FTIR results show that the intensity of the peak absorbance of the O–H functional group decreased with aging but the intensity of the peak absorbance of the C–H and C=O functional groups increased with aging. Changes in the chemical structure of the cellulose paper during thermal aging in mineral oil can be analyzed by an oxidation process of the cellulose paper and the reaction process between the carboxylic acids in the mineral oil and the hydroxyl groups on the cellulose. The correlation between the functional groups and the average number of chain scissions of transformer paper gives initial information that the transformer paper performance can be identified by using a spectroscopic technique as a non-destructive diagnostic technique.

  7. The roles of thermal insulation and heat storage in the energy performance of the wall materials: a simulation study.

    Science.gov (United States)

    Long, Linshuang; Ye, Hong

    2016-04-07

    A high-performance envelope is the prerequisite and foundation to a zero energy building. The thermal conductivity and volumetric heat capacity of a wall are two thermophysical properties that strongly influence the energy performance. Although many case studies have been performed, the results failed to give a big picture of the roles of these properties in the energy performance of an active building. In this work, a traversal study on the energy performance of a standard room with all potential wall materials was performed for the first time. It was revealed that both heat storage materials and insulation materials are suitable for external walls. However, the importances of those materials are distinct in different situations: the heat storage plays a primary role when the thermal conductivity of the material is relatively high, but the effect of the thermal insulation is dominant when the conductivity is relatively low. Regarding internal walls, they are less significant to the energy performance than the external ones, and they need exclusively the heat storage materials with a high thermal conductivity. These requirements for materials are consistent under various climate conditions. This study may provide a roadmap for the material scientists interested in developing high-performance wall materials.

  8. The roles of thermal insulation and heat storage in the energy performance of the wall materials: a simulation study

    Science.gov (United States)

    Long, Linshuang; Ye, Hong

    2016-01-01

    A high-performance envelope is the prerequisite and foundation to a zero energy building. The thermal conductivity and volumetric heat capacity of a wall are two thermophysical properties that strongly influence the energy performance. Although many case studies have been performed, the results failed to give a big picture of the roles of these properties in the energy performance of an active building. In this work, a traversal study on the energy performance of a standard room with all potential wall materials was performed for the first time. It was revealed that both heat storage materials and insulation materials are suitable for external walls. However, the importances of those materials are distinct in different situations: the heat storage plays a primary role when the thermal conductivity of the material is relatively high, but the effect of the thermal insulation is dominant when the conductivity is relatively low. Regarding internal walls, they are less significant to the energy performance than the external ones, and they need exclusively the heat storage materials with a high thermal conductivity. These requirements for materials are consistent under various climate conditions. This study may provide a roadmap for the material scientists interested in developing high-performance wall materials. PMID:27052186

  9. Integrated MLI: Advanced Thermal Insulation Using Micro-Molding Technology, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Current Multilayer Insulation (MLI) technology is over 50 years old, and is typically comprised of 10 to 120 layers of metalized polymer films separated by polyester...

  10. Thermal insulation of buildings classified as historical monuments with particular emphasis on moisture protection; Hygrisch motivierter Waermeschutz von Altbauten mit denkmalgeschuetzter Fassade

    Energy Technology Data Exchange (ETDEWEB)

    Haeupl, P.; Martin, R.; Fechner, H.; Neue, J. [Technische Univ. Dresden (Germany). Inst. fuer Bauklimatik

    1997-12-31

    Buildings classified as historical must not be fitted with external thermal insulation elements. This project investigates a `gentle` type of an internal thermal insulation system with capillary activity permitting diffusion. A 120-year-old building with a historical house-front was thermally insulated at the inside using a 30-millimetre-thick calcium silicate plate with embedded fibres having capillary activity. The paper discusses the heat flow densities between the internal thermal insulation and the original part of the structure. Moisture fields in the wall in the case of mineral wool insulation and internal thermal insulation with capillary activity are compared. Moisture distribution in the area of the juncture between masonry and window and in the area of the beam head is shown by means of diagrams. (MSK) [Deutsch] Weil bei denkmalgeschuetzten Fassanden ein aussen angebrachtes Thermoverbundsystem nicht moeglich ist, wird in diesem Projekt eine sanfte kapillaraktive, diffusionsoffene Innendaemmung untersucht. Als Referenzobjekt wurde ein etwa 120 Jahre altes Gruenderzeithaus mit denkmalgeschuetzter Fassade mit einer 30mm dicken faserdotierten kapillaraktiven Calciumsilikatplatte innenseitig gedaemmt. Im Folgenden werden die Waermestromdichten zwischen Innendaemmung und Altkonstruktion erlaeutert. Die Feuchtefelder in der Wand bei Mineralwolleindaemmung und bei kapillaraktiver Innendaemmung werden verglichen. Die Feuchteverteilung im Bereich des Fenteranschlusses und des Balkenkopfes wird in Diagrammen dargestellt.

  11. Low thermal conductivity of porous Al{sub 2}O{sub 3} foams for SOFC insulation

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Y.W. [Dept. Mat. Sci. Eng., National Taiwan University, Roosevelt Rd. Section 4, Taipei 106, Taiwan (China); Wei, W.C.J., E-mail: wjwei@ntu.edu.tw [Dept. Mat. Sci. Eng., National Taiwan University, Roosevelt Rd. Section 4, Taipei 106, Taiwan (China); Hsueh, C.H. [Dept. Mat. Sci. Eng., National Taiwan University, Roosevelt Rd. Section 4, Taipei 106, Taiwan (China); Materials Sci. Tech. Div., Oak Ridge National Lab., Oak Ridge, TN (United States); Dept. Physics and Astronomy, Univ. Tennessee, Knoxville, TN (United States)

    2011-09-15

    Highlights: {yields} Porous Al{sub 2}O{sub 3} foams with total porosity of 85-95% were made by direct foaming technique. {yields} Extremely low thermal conductivities of 0.05 W m{sup -1} K{sup -1} at room temperature and 0.14 W m{sup -1} K{sup -1} at 800 deg. C are achieved. {yields} Photon radiation in IR range dominates thermal conductivity >400 deg. C. - Abstract: Ceramic thermal insulator is one of the important thermal management devices for SOFC operating at medium temperatures (<800 deg. C). This study used colloidal dispersion, direct foaming method, microwave drying, and sintering to prepare porous Al{sub 2}O{sub 3} foams with total porosity of 85-95%. The measurement of thermal conductivity by a hot-wire method was conducted. The effects of cell structure on thermal conductivity were investigated with scanning electron microscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR). By optimizing the cell structures of Al{sub 2}O{sub 3} foams, low thermal conductivities of 0.05 W m{sup -1} K{sup -1} at room temperature and 0.14 W m{sup -1} K{sup -1} at 800 deg. C were achieved in this study.

  12. Thermal Characteristics of Multilayer Insulation Materials for Flexible Thin-Film Solar Cell Array of Stratospheric Airship

    Directory of Open Access Journals (Sweden)

    Kangwen Sun

    2014-01-01

    Full Text Available Flexible thin-film solar cell is an efficient energy system on the surface of stratospheric airship for utilizing the solar energy. In order to ensure the normal operation of airship platform, the thermal control problem between the flexible thin-film solar cell and the airship envelope should be properly resolved. In this paper, a multilayer insulation material (MLI is developed first, and low temperature environment test is carried out to verify the insulation effect of MLI. Then, a thermal heat transfer model of flexible thin-film solar cell and MLI is proposed, and the equivalent thermal conductivity coefficients of flexible thin-film solar cell and Nomex honeycomb are calculated based on the environment test and the temperature profile of flexible thin-film solar cell versus each layer of MLI. Finally, FLUENT is used for modeling and simulation analysis on the flexible thin-film solar cell and MLI, and the simulation results agree well with the experimental data, which validate the correctness of the proposed heat transfer model of MLI. In some way, our study can provide helpful support for further engineering applications of flexible thin-film solar cell.

  13. Resistance noise spectroscopy across the thermally and electrically driven metal-insulator transitions in VO2 nanobeams

    Science.gov (United States)

    Alsaqqa, Ali; Kilcoyne, Colin; Singh, Sujay; Horrocks, Gregory; Marley, Peter; Banerjee, Sarbajit; Sambandamurthy, G.

    Vanadium dioxide (VO2) is a strongly correlated material that exhibits a sharp thermally driven metal-insulator transition at Tc ~ 340 K. The transition can also be triggered by a DC voltage in the insulating phase with a threshold (Vth) behavior. The mechanisms behind these transitions are hotly discussed and resistance noise spectroscopy is a suitable tool to delineate different transport mechanisms in correlated systems. We present results from a systematic study of the low frequency (1 mHz noise behavior in VO2 nanobeams across the thermally and electrically driven transitions. In the thermal transition, the power spectral density (PSD) of the resistance noise is unchanged as we approach Tc from 300 K and an abrupt drop in the magnitude is seen above Tc and it remains unchanged till 400 K. However, the noise behavior in the electrically driven case is distinctly different: as the voltage is ramped from zero, the PSD gradually increases by an order of magnitude before reaching Vth and an abrupt increase is seen at Vth. The noise magnitude decreases above Vth, approaching the V = 0 value. The individual roles of percolation, Joule heating and signatures of correlated behavior will be discussed. This work is supported by NSF DMR 0847324.

  14. Determination of the Thermal Insulation for the Model Building Approach and the Global Effects in Turkey

    Directory of Open Access Journals (Sweden)

    Cenk Onan

    2014-08-01

    Full Text Available One of the most important considerations to be considered in the design of energy efficient buildings is the thickness of the insulation to be applied to the building. In this study the existing building stock in Turkey has been investigated depending on parameters such as the height and the area. A model building has been created covering all of these buildings. Fuel emission reduction of combustion system was calculated in the case of insulation applied to this model building. Heat loss of the existing building stock and exhaust emissions and the contribution to the country's economy with the model building methodology are also determined. The results show that the optimum insulation thicknesses vary between 3.21 and 7.12 cm, the energy savings vary between 9.23 US$/m2 and43.95 US$/m2, and the payback periods vary between 1 and 8.8 years depending on the regions. As a result of the study when the optimum insulation thickness is applied in the model building, the total energy savings for the country are calculated to be 41.7 billion US$. And also total CO2 emissions for the country are calculated to be 57.2 billion kg CO2 per year after insulation.

  15. Fabrication of Ge-on-insulator wafers by Smart-CutTM with thermal management for undamaged donor Ge wafers

    Science.gov (United States)

    Kim, Munho; Cho, Sang June; Jayeshbhai Dave, Yash; Mi, Hongyi; Mikael, Solomon; Seo, Jung-Hun; Yoon, Jung U.; Ma, Zhenqiang

    2018-01-01

    Newly engineered substrates consisting of semiconductor-on-insulator are gaining much attention as starting materials for the subsequent transfer of semiconductor nanomembranes via selective etching of the insulating layer. Germanium-on-insulator (GeOI) substrates are critically important because of the versatile applications of Ge nanomembranes (Ge NMs) toward electronic and optoelectronic devices. Among various fabrication techniques, the Smart-CutTM technique is more attractive than other methods because a high temperature annealing process can be avoided. Another advantage of Smart-CutTM is the reusability of the donor Ge wafer. However, it is very difficult to realize an undamaged Ge wafer because there exists a large mismatch in the coefficient of thermal expansion among the layers. Although an undamaged donor Ge wafer is a prerequisite for its reuse, research related to this issue has not yet been reported. Here we report the fabrication of 4-inch GeOI substrates using the direct wafer bonding and Smart-CutTM process with a low thermal budget. In addition, a thermo-mechanical simulation of GeOI was performed by COMSOL to analyze induced thermal stress in each layer of GeOI. Crack-free donor Ge wafers were obtained by annealing at 250 °C for 10 h. Raman spectroscopy and x-ray diffraction (XRD) indicated similarly favorable crystalline quality of the Ge layer in GeOI compared to that of bulk Ge. In addition, Ge p-n diodes using transferred Ge NM indicate a clear rectifying behavior with an on and off current ratio of 500 at ±1 V. This demonstration offers great promise for high performance transferrable Ge NM-based device applications.

  16. Thermal conductivity: recent developments on insulating and new materials; La conductivite thermique: developpements recents sur les isolants et les materiaux nouveaux

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This workshop organized by the thermo-kinetics section of the French society of thermal engineers deals with recent developments concerning insulating, dielectric and composite materials. The seven papers presented during this workshop concern the methods and results of thermal conductivity measurements performed in these materials and the possible applications of these materials in aerospace industry (carbon foams, ceramic-based composite materials), civil engineering (glazing materials, aerogels), power electronics (dielectric thin films, ceramics), and in other industries (heat resistant and thermal insulating materials). (J.S.)

  17. Thermal performance of FRSI/graphite epoxy materials for the Orbiter TPS application. [Flexible Reusable Surface Insulation

    Science.gov (United States)

    Norman, I.; Ritrivi, C. A.; Tillian, D. J.; Maraia, R. J.

    1984-01-01

    Radiant tests have been conducted to evaluate the performance of the Flexible Reusable Surface Insulation (FRSI) when bonded to Graphite/Epoxy (G/E) honeycomb sandwich structures. The results from this study indicate reasonable agreement with the baseline FRSI properties that existed prior to this test program. An updated Thermal Math Model (TMM) prediction technique was developed, with the use of the well-defined boundary conditions, which appears to be valid in analyzing the complex heat transfer associated with the honeycomb structure. The updated TM analysis of flight data resulted in good agreement of predicted temperatures with flight data for bondline responses of Orbiter FRSI/GE TPS applications.

  18. Influence of germanium on thermal dewetting and agglomeration of the silicon template layer in thin silicon-on-insulator

    International Nuclear Information System (INIS)

    Zhang, P P; Yang, B; Rugheimer, P P; Roberts, M M; Savage, D E; Lagally, M G; Liu Feng

    2009-01-01

    We investigate the influence of heteroepitaxially grown Ge on the thermal dewetting and agglomeration of the Si(0 0 1) template layer in ultrathin silicon-on-insulator (SOI). We show that increasing Ge coverage gradually destroys the long-range ordering of 3D nanocrystals along the (1 3 0) directions and the 3D nanocrystal shape anisotropy that are observed in the dewetting and agglomeration of pure SOI(0 0 1). The results are qualitatively explained by Ge-induced bond weakening and decreased surface energy anisotropy. Ge lowers the dewetting and agglomeration temperature to as low as 700 0 C.

  19. California residential energy standards: problems and recommendations relating to implementation, enforcement, and design. [Thermal insulation

    Energy Technology Data Exchange (ETDEWEB)

    1977-08-01

    Documents relevant to the development and implementation of the California energy insulation standards for new residential buildings were evaluated and a survey was conducted to determine problems encountered in the implementation, enforcement, and design aspects of the standards. The impact of the standards on enforcement agencies, designers, builders and developers, manufacturers and suppliers, consumers, and the building process in general is summarized. The impact on construction costs and energy savings varies considerably because of the wide variation in prior insulation practices and climatic conditions in California. The report concludes with a series of recommendations covering all levels of government and the building process. (MCW)

  20. Strain and Thermally Induced Magnetic Dynamics and Spin Current in Magnetic Insulators Subject to Transient Optical Grating

    Directory of Open Access Journals (Sweden)

    Xi-Guang Wang

    2017-07-01

    Full Text Available We analyze the magnetic dynamics and particularly the spin current in an open-circuit ferromagnetic insulator irradiated by two intense, phase-locked laser pulses. The interference of the laser beams generates a transient optical grating and a transient spatiotemporal temperature distribution. Both effects lead to elastic and heat waves at the surface and into the bulk of the sample. The strain induced spin current as well as the thermally induced magnonic spin current are evaluated numerically on the basis of micromagnetic simulations using solutions of the heat equation. We observe that the thermo-elastically induced magnonic spin current propagates on a distance larger than the characteristic size of thermal profile, an effect useful for applications in remote detection of spin caloritronics phenomena. Our findings point out that exploiting strain adds a new twist to heat-assisted magnetic switching and spin-current generation for spintronic applications.

  1. Heat conduction coefficient and coefficient of linear thermal expansion of electric insulation materials for superconducting magnetic system

    International Nuclear Information System (INIS)

    Deev, V.I.; Sobolev, V.P.; Kruglov, A.B.; Pridantsev, A.I.

    1984-01-01

    Results of experimental investigation of heat conduction coefficient and coefficient of linear thermal expansion and thermal shrinkages of the STEF-1 textolite-glass widely used in superconducting magnetic systems as electric insulating and structural material are presented. Samples of two types have been died: sample axisa is perpendicular to a plae of fiberglass layers ad sample axis is parallel to a plane of fiberglass layers. Heat conduction coefficient was decreased almost a five times with temperature decrease from 300 up to 5K and was slightly dependent on a sample type. Temperature variation of linear dimensions in a sample of the first type occurs in twice as fast as compared to the sample of the second type

  2. Investigation of the Mechanical Properties of Hybrid Carbon-Hemp Laminated Composites Used as Thermal Insulation for Different Industrial Applications

    Directory of Open Access Journals (Sweden)

    M. L. Scutaru

    2014-04-01

    Full Text Available Carbon-hemp composite laminate provides good thermal properties. For this reason this type of material is presently being used for various applications like insulator for airplanes, spaceships, nuclear reactors, and so forth. Unfortunately their mechanical properties are less studied. These characteristics are very important since they should be guaranteed also for important mechanical stress in addition to the thermal one. The present paper presents a study regarding the impact testing of some hybrid composite laminate panels based on polyester resin reinforced with both carbon and hemp fabric. The effects of different impact speeds on the mechanical behavior of these panels have been analyzed. The paper lays stress on the characterization of this hybrid composite laminate regarding the impact behavior of these panels by dropping a weight with low velocity.

  3. Synthesis and characterization of innovative insulation materials

    Directory of Open Access Journals (Sweden)

    Skaropoulou Aggeliki

    2018-01-01

    Full Text Available Insulation elements are distinguished in inorganic fibrous and organic foamed materials. Foamed insulation materials are of great acceptance and use, but their major disadvantage is their flammability. In case of fire, they tend to transmit the flame producing toxic gases. In this paper, the synthesis and characterization of innovative inorganic insulation materials with properties competitive to commercial is presented. Their synthesis involves the mixing of inorganic raw material and water with reinforcing agent or/and foaming agent leading to the formation of a gel. Depending on raw materials nature, the insulation material is produced by freeze drying or ambient drying techniques of the gel. The raw material used are chemically benign and abundantly available materials, or industrial by-products and the final products are non-toxic and, in some cases, non-flammable. Their density and thermal conductivity was measured and found 0.02-0.06 g/cm3 and 0.03-0.04 W/mK, respectively.

  4. Preparation and properties of thermal insulation coatings with a sodium stearate-modified shell powder as a filler

    Science.gov (United States)

    Tang, Qiang; Zhang, Ya-mei; Zhang, Pei-gen; Shi, Jin-jie; Tian, Wu-bian; Sun, Zheng-ming

    2017-10-01

    Waste shell stacking with odor and toxicity is a serious hazard to our living environment. To make effective use of the natural resources, the shell powder was applied as a filler of outdoor thermal insulation coatings. Sodium stearate (SS) was used to modify the properties of shell powder to reduce its agglomeration and to increase its compatibility with the emulsion. The oil absorption rate and the spectrum reflectance of the shell powder show that the optimized content of SS as a modifier is 1.5wt%. The total spectrum reflectance of the coating made with the shell powder that is modified at this optimum SS content is 9.33% higher than that without any modification. At the optimum SS content of 1.5wt%, the thermal insulation of the coatings is improved by 1.0°C for the cement mortar board and 1.6°C for the steel plate, respectively. The scouring resistance of the coating with the 1.5wt% SS-modified shell powder is three times that of the coating without modification.

  5. Cement blocks with EVA waste for extensive modular green roof: contribution of the components for thermal insulation

    Directory of Open Access Journals (Sweden)

    A. B. DE MELO

    Full Text Available Abstract Green roofs can contribute in many ways to the quality of the environment, being known for reducing the heat transfer to the interior of the buildings. Amongst the available techniques for the execution of this type of covering, the use of light cement blocks which are compatible with the system of extensive modular green roofs is proposed. For the light cement blocks, produced with EVA aggregates (waste from the footwear industry, an additional contribution in the capacity of thermal insulation of the proposed green roof is expected. In the present article, the demonstration of such contribution is intended through measurements carried out in prototypes in hot and humid climates. After characterizing the capacity of thermal insulation of the proposed green roof, with different types of conventional covering as a reference, an additional contribution of the component used in this green roof was identified by making comparisons with measurements collected from another green roof, executed with cement blocks without the presence of the EVA aggregates. In the experiments, external and internal surface temperatures were measured in each of the prototypes' coverings, as well as the air temperatures in the internal and external environments. From the analysis of the data for a typical summer day, it was possible to prove that the proposed green roof presented the lowest temperature ranges, considering the internal air and surface temperatures. The presence of the EVA aggregates in the proposed blocks contributed to the decrease of the internal temperatures.

  6. Life cycle assessment of hemp cultivation and use of hemp-based thermal insulator materials in buildings.

    Science.gov (United States)

    Zampori, Luca; Dotelli, Giovanni; Vernelli, Valeria

    2013-07-02

    The aim of this research is to assess the sustainability of a natural fiber, such as hemp (Cannabis sativa), and its use as thermal insulator for building applications. The sustainability of hemp was quantified by life cycle assessment (LCA) and particular attention was given to the amount of CO2eq of the whole process, and the indicator greenhouse gas protocol (GGP) was selected to quantify CO2eq emissions. In this study also CO2 uptake of hemp was considered. Two different allocation procedures (i.e., mass and economic) were adopted. Other indicators, such as Cumulative Energy Demand (CED) and EcoIndicator99 H were calculated. The production of 1 ha yielded 15 ton of hemp, whose global warming potential (GWP100) was equal to about -26.01 ton CO2eq: the amount allocated to the technical fiber (20% of the total amount of hemp biomass) was -5.52 ton CO2eq when mass allocation was used, and -5.54 ton CO2eq when economic allocation was applied. The sustainability for building applications was quantified by considering an insulation panel made by hemp fiber (85%) and polyester fiber (15%) in 1 m(2) of wall having a thermal transmittance (U) equal to 0.2 W/m(2)_K. The environmental performances of the hemp-based panel were compared to those of a rockwool-based one.

  7. Thermal performance measurements of a 100 percent polyester MLI [multilayer insulation] system for the Superconducting Super Collider

    International Nuclear Information System (INIS)

    Boroski, W.N.; Gonczy, J.D.; Niemann, R.C.

    1989-09-01

    Thermal performance measurements of a 100 percent polyester multilayer insulation (MLI) system for the Superconducting Super Collider (SSC) were conducted in a Heat Leak Test Facility (HLTF) under three experimental test arrangements. Each experiment measured the thermal performance of a 32-layer MLI blanket instrumented with twenty foil sensors to measure interstitial layer temperatures. Heat leak values and sensor temperatures were monitored during transient and steady state conditions under both design and degraded insulating vacuums. Heat leak values were measured using a heatmeter. MLI interstitial layer temperatures were measured using Cryogenic Linear Temperature Sensors (CLTS). Platinum resistors monitored system temperatures. High vacuum was measured using ion gauges; degraded vacuum employed thermocouple gauges. A four-wire system monitored instrumentation sensors and calibration heaters. An on-line computerized data acquisition system recorded and processes data. This paper reports on the instrumentation and experimental preparation used in carrying out these measurements. In complement with this paper is an associate paper bearing the same title head, but with the title extension 'Part 2: Laboratory results (300K--80K). 13 refs., 7 figs

  8. HiPTI - High Performance Thermal Insulation, Annex 39 to IEA/ECBCS-Implementing Agreement. Vacuum insulation in the building sector. Systems and applications

    Energy Technology Data Exchange (ETDEWEB)

    Binz, A.; Moosmann, A.; Steinke, G.; Schonhardt, U.; Fregnan, F. [Fachhochschule Nordwestschweiz (FHNW), Muttenz (Switzerland); Simmler, H.; Brunner, S.; Ghazi, K.; Bundi, R. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Duebendorf (Switzerland); Heinemann, U.; Schwab, H. [ZAE Bayern, Wuerzburg (Germany); Cauberg, H.; Tenpierik, M. [Delft University of Technology, Delft (Netherlands); Johannesson, G.; Thorsell, T. [Royal Institute of Technology (KTH), Stockholm (Sweden); Erb, M.; Nussbaumer, B. [Dr. Eicher und Pauli AG, Basel and Bern (Switzerland)

    2005-07-01

    This final report on vacuum insulation panels (VIP) presents and discusses the work done under IEA/Energy Conservation in Buildings and Community Systems (ECBCS) Annex 39, subtask B on the basis of a wide selection of reports from practice. The report shows how the building trade deals with this new material today, the experience gained and the conclusions drawn from this work. As well as presenting recommendations for the practical use of VIP, the report also addresses questions regarding the effective insulation values to be expected with current VIP, whose insulation performance is stated as being a factor of five to eight times better than conventional insulation. The introduction of this novel material in the building trade is discussed. Open questions and risks are examined. The fundamentals of vacuum insulation panels are discussed and the prerequisites, risks and optimal application of these materials in the building trade are examined.

  9. Thermal Simulation of Switching Pulses in an Insulated Gate Bipolar Transistor (IGBT) Power Module

    Science.gov (United States)

    2015-02-01

    prepared with SolidWorks computer-aided design software. The module has 8 silicon IGBTs mounted on copper (Cu) lands bonded onto a dielectric circuit...aluminum nitride ARL US Army Research Laboratory Cu copper IGBT insulated gate bipolar transistor ms millisecond 3D 3-dimensional W watt...RDRL CIO LL TECHL LIB 1 GOVT PRNTG OFC (PDF) ATTN A MALHOTRA 5 US ARMY RSRCH LAB (PDF) ATTN RDRL SED C W TIPTON ATTN RDRL SED P D

  10. Mechanical Behavior of Syntactic Foams for Deep Sea Thermally Insulated Pipeline

    OpenAIRE

    Choqueuse, Dominique; Davies, Peter; Perreux, Dominique; Sohier, L; Cognard, Jean Yves

    2010-01-01

    Ultra Deep offshore oil exploitation (down to 3000 meters depth) presents new challenges to offshore engineering and operating companies. Flow assurance and particularly the selection of insulation materials to be applied to pipe lines are of primary importance, and are the focus of much industry interest for deepwater applications. Polymeric and composite materials, particularly syntactic foams, are now widely used for this application, so the understanding of their behavior under extreme co...

  11. Description and characterization of systems for external insulation and retrofitting for Denmark with emphasis on the thermal performance

    DEFF Research Database (Denmark)

    Rudbeck, Claus Christian; Svendsen, Sv Aa Højgaard

    1998-01-01

    to solve these problems insulation is often part of the retrofitting. As internal insulation has many disadvantages with regards to heat and moisture only systems for external insulation will be mentioned here.As there are several different systems for external insulation, each with different properties...

  12. A new method for the determination of thermal properties of the insulation material used in district heating pipes; Ny metod foer att bestaemma fjaerrvaermeroers isoleringsfoermaaga

    Energy Technology Data Exchange (ETDEWEB)

    Adl-Zarrabi, Bijan [SP Swedish National Testing and Research Inst., Boraas (Sweden)

    2005-07-01

    Thermal resistance of district heat pipes declines during its lifetime and this leads to increased thermal losses. To be able to change the insufficient pipes in right time has a large economical impact. The conventional measurement techniques for determinations of thermal properties of insulation of the pipe are abusive and expensive. In the present project the 'Transient Plan Source' TPS-method has been studied as an alternative method. TPS-method can be used in the field and measurements are not time demanding. Thermal conductivity of district heating pipe (polyurethane foam) is measured at 20 deg C and 50 deg C with Transient Plane Source (TPS) method. Three different setups were investigated. In one of the setups the TPS sensor is embedded in the insulation of district heating pipe. Comparison between measured results and the reference value showed that the measured results by TPS method were higher than reference values. It may depend on a number of different parameters, for example TPS method measure bulk properties and the reference value is an apparent value. Relative change of thermal conductivity per Celsius degree of temperature was in the same level as reference value. It is possible to embed the TPS sensor in the insulation of the district heating pipes. The measured relative change of conductivity was in the same range as the reference value. Thus, TPS method can be used for control measurements concerning the insulation properties of district heating pipes in the field and in service.

  13. Multi-scale cellulose based new bio-aerogel composites with thermal super-insulating and tunable mechanical properties.

    Science.gov (United States)

    Seantier, Bastien; Bendahou, Dounia; Bendahou, Abdelkader; Grohens, Yves; Kaddami, Hamid

    2016-03-15

    Bio-composite aerogels based on bleached cellulose fibers (BCF) and cellulose nanoparticles having various morphological and physico-chemical characteristics are prepared by a freeze-drying technique and characterized. The various composite aerogels obtained were compared to a BCF aerogel used as the reference. Severe changes in the material morphology were observed by SEM and AFM due to a variation of the cellulose nanoparticle properties such as the aspect ratio, the crystalline index and the surface charge density. BCF fibers form a 3D network and they are surrounded by the cellulose nanoparticle thin films inducing a significant reduction of the size of the pores in comparison with a neat BCF based aerogel. BET analyses confirm the appearance of a new organization structure with pores of nanometric sizes. As a consequence, a decrease of the thermal conductivities is observed from 28mWm(-1)K(-1) (BCF aerogel) to 23mWm(-1)K(-1) (bio-composite aerogel), which is below the air conductivity (25mWm(-1)K(-1)). This improvement of the insulation properties for composite materials is more pronounced for aerogels based on cellulose nanoparticles having a low crystalline index and high surface charge (NFC-2h). The significant improvement of their insulation properties allows the bio-composite aerogels to enter the super-insulating materials family. The characteristics of cellulose nanoparticles also influence the mechanical properties of the bio-composite aerogels. A significant improvement of the mechanical properties under compression is obtained by self-organization, yielding a multi-scale architecture of the cellulose nanoparticles in the bio-composite aerogels. In this case, the mechanical property is more dependent on the morphology of the composite aerogel rather than the intrinsic characteristics of the cellulose nanoparticles. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. The health of retired fibrous glass workers.

    Science.gov (United States)

    Enterline, P E; Henderson, V

    1975-03-01

    A total of 416 men, retiring during the period 1945 to 1972 from six plants engaged mainly in the manufacture of fibrous glass insulation, were studied to see how their mortality experience compared with that of white men in the entire United States living in comparable age and time intervals. The mean follow-up period from first exposure was about 30 years. Overall mortality was low and there was no evidence of an excess in respiratory cancer mortality. No mesotheliomas were noted. For 115 men retiring from the same six plants during the period 1945 to 1972 due to a disability the distribution of disabilities by cause was compared with an expected distribution based on the experience of the Social Security Administration. This comparison showed no evidence of any unusual health hazards among fibrous glass workers, except a possible excess in chronic bronchitis.

  15. Current-induced metal-insulator transition in VO x thin film prepared by rapid-thermal-annealing

    International Nuclear Information System (INIS)

    Cho, Choong-Rae; Cho, SungIl; Vadim, Sidorkin; Jung, Ranju; Yoo, Inkyeong

    2006-01-01

    The phenomenon of metal-insulator transition (MIT) in polycrystalline VO x thin films and their preparations have been studied. The films were prepared by sputtering of vanadium thin films succeeded by Rapid Thermal Annealing (RTA) in oxygen ambient at 500 deg. C. Crystalline, compositional, and morphological characterizations reveal a continuous change of phase from vanadium metal to the highest oxide phase, V 2 O 5 , with the time of annealing. Electrical MIT switching has been observed in these films. Sweeping mode, electrode area, and temperature dependent MIT has been studied in Pt/VO x /Pt vertical structure. The important parameters for MIT in VO x have been found to be the current density and the electric field, which depend on carrier density in the films

  16. The thermal insulating materials and its coatings for underground piping; Los aislamientos termicos y sus recubrimientos para tuberias subterraneos

    Energy Technology Data Exchange (ETDEWEB)

    Salcido Lopez, Salvador [Aislantes Minerales, S. A. de C. V. Mexico, D. F. (Mexico)

    1994-12-31

    Energy Saving through the adequate selection and application of the thermal insulating materials, as well as its coatings for underground piping conducting fluids, both at high and at low temperature. The benefits are outlined at economical level for the investor as well as at ecological level (of vital importance today) and are observed as practical examples in industrial and commercial processes. [Espanol] Ahorro de energeticos mediante la adecuada seleccion y aplicacion de los aislamientos termicos, asi como de sus recubrimientos para tuberias subterraneas que conducen fluidos tanto en alta como en baja temperatura. Los beneficios son destacados tanto a nivel economico para el inversionista, como a nivel ecologico (de vital importancia en la actualidad), y son observados con ejemplos practicos en procesos industriales y comerciales.

  17. Radiolytic degradation of hexabromocyclododecane in waste water from thermal insulation-treatment factory with gamma ray irradiation

    International Nuclear Information System (INIS)

    Wu, Xing-Zheng; Toriyama, Keisuke; Harii, Tomoaki; Katoh, Yoshio; Taniguchi, Tetsuo

    2008-01-01

    Radiolytic, and radiolytic/biological decompositions of hexabromocyclododecane (HBCD) in primary and ultimate waste waters from a thermal insulation-treatment process and a factory of polyester process are studied with gamma ray irradiation. Concentrations and degradation ratios of HBCD, and Br - concentrations are determined before and after gamma ray irradiation. Also, total organic carbon (TOC), chemical oxygen demand (COD), and biochemical oxygen demand (BOD) are determined to evaluate the decomposition of total organic compounds. As a result, about 72.5% of HBCD in ultimate waste water were decomposed with dose of 100 kGy. Furthermore, about 98% of HBCD, nearly all organic compounds were removed after the combination of radiolytic/biological treatments. (author)

  18. Ecological Risks in Residential Premises Arising from Thermal Insulation by Pouring

    Science.gov (United States)

    Timofeeva, S. S.; Timofeev, S. S.

    2017-11-01

    The residents of modern megacities are exposed to environmental risks arising both directly in the urban environment and their own dwellings. Modern polymeric building materials are the sources of toxic substances release into the air that have a significant impact on the population health. The objective of the work is the ecological and hygienic study of the air in the apartments of Irkutsk after repair work on the roof and walls insulation using the technology of pouring and calculation of the potential environmental risk for the residents. The object of the research was the indoor air in one of the houses in Irkutsk tested for formaldehyde and other toxic substances. After putting the house into operation, some defects were found - the freezing of the walls of the building attic part. During the repair work, the mansard part of the building was heat-insulated by the pouring method using the composite material “Poroplast CF 02”. High concentrations of formaldehyde and styrene were detected in the apartments exceeding the MPC in 4-8 times. The hazard ratio for inhalation exposure to harmful substances exceeds the safety level by 10 times. Consequently, there is a high probability of obtaining acute and chronic poisoning and developing cancer.

  19. Strength of Fibrous Composites

    CERN Document Server

    Huang, Zheng-Ming

    2012-01-01

    "Strength of Fibrous Composites" addresses evaluation of the strength of a fibrous composite by using its constituent material properties and its fiber architecture parameters. Having gone through the book, a reader is able to predict the progressive failure behavior and ultimate strength of a fibrous laminate subjected to an arbitrary load condition in terms of the constituent fiber and matrix properties, as well as fiber geometric parameters. The book is useful to researchers and engineers working on design and analysis for composite materials. Dr. Zheng-Ming Huang is a professor at the School of Aerospace Engineering & Applied Mechanics, Tongji University, China. Mr. Ye-Xin Zhou is a PhD candidate at the Department of Mechanical Engineering, the University of Hong Kong, China.

  20. Permeability and compression of fibrous porous media generated from dilute suspensions of fiberglass debris during a loss of coolant accident

    International Nuclear Information System (INIS)

    Lee, Saya; Abdulsattar, Suhaeb S.; Vaghetto, Rodolfo; Hassan, Yassin A.

    2015-01-01

    Highlights: • Experimental investigation on fibrous debris buildup was conducted. • Head loss through fibrous media was recorded at different approach velocities. • A head loss model through fibrous media was proposed for high porosity (>0.99). • A compression model of fibrous media was developed. - Abstract: Permeability of fibrous porous media has been studied for decades in various engineering applications, including liquid purifications, air filters, and textiles. In nuclear engineering, fiberglass has been found to be a hazard during a Loss-of-Coolant Accident. The high energy steam jet from a break impinges on surrounding fiberglass insulation materials, producing a large amount of fibrous debris. The fibrous debris is then transported through the reactor containment and reaches the sump strainers. Accumulation of such debris on the surface of the strainers produces a fibrous bed, which is a fibrous porous medium that can undermine reactor core cooling. The present study investigated the buildup of fibrous porous media on two types of perforated plate and the pressure drop through the fibrous porous media without chemical effect. The development of the fibrous bed was visually recorded in order to correlate the pressure drop, the approach velocity, and the thickness of the fibrous porous media. The experimental results were compared to semi-theoretical models and theoretical models proposed by other researchers. Additionally, a compression model was developed to predict the thickness and the local porosity of a fibrous bed as a function of pressure

  1. Solvent-free fabrication of thermally conductive insulating epoxy composites with boron nitride nanoplatelets as fillers.

    Science.gov (United States)

    Wang, Zifeng; Fu, Yuqiao; Meng, Wenjun; Zhi, Chunyi

    2014-01-01

    A solvent-free method for the fabrication of thermally conductive epoxy-boron nitride (BN) nanoplatelet composite material is developed in this study. By this method, polymer composites with nearly any filler fractions can be easily fabricated. The maximum thermal conductivity reaches 5.24 W/mK, which is 1,600% improvement in comparison with that of pristine epoxy material. In addition, the as-fabricated samples exhibit excellent overall performances with great mechanical property and thermal stability well preserved.

  2. Methodology for characterization of corrosive agents of thermal insulating foams; Desenvolvimento de metodologia para caracterizacao de agentes corrosivos de espumas de isolamento termico

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Flavio V. Vasques de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Fundacao Coordenacao de Projetos, Pesquisas e Estudos Tecnologicos - COPPETEC; Mattos, Oscar R.; Mota, Rafael O. da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Metalurgica e de Materiais; Margarit-Mattos, Isabel C.P. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Escola de Quimica. Dept. de Processos Organicos; Quintela, Joaquim P. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Vieira, Magda M. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2005-07-01

    Warming up oil and derivatives is a required procedure to make their transportation more efficient due to the increase in fluidity. Therefore, the use of thermally insulated pipeline becomes essential. The commonly practice has been the use of pipelines covered with an optional anticorrosive coating, followed by a polyurethane foam layer, as thermal insulator, and a polyethylene top coating for mechanical protection. During the life time of the pipeline, local ruptures of the polyethylene coating frequently occur, allowing the water permeation throughout the thermal insulator. This water may cause foam leaching that would release corrosive agents on the external wall pipe. The objective of the present work was to investigate the effects of the blowing agents, the addition of flame retardant to the foam as well as operating temperatures on the generation of corrosive solutions on the external wall of thermally insulated pipes. In this sense, polyurethane foams expanded with HCFC-141b, CFC-11 and CO{sub 2}, with and without flame retardant, were evaluated at the temperatures of 80 and 120 deg C. (author)

  3. Applications of fibrous substrates containing insolubilized phase change polymers

    Science.gov (United States)

    Vigo, Tyrone L.; Bruno, Joseph S.

    1993-01-01

    Incorporation of polyethylene glycols into fibrous substrates produces several improved functional properties when they are insolubilized by crosslinking with a methylolamide resin or by polyacetal formation by their reaction with glyoxal. The range of molecular weights of polyols that may be insolubilized is broad as are the curing conditions (0.25-10 min at 80-200C). Most representative fiber types and blends (natural and synthetic) and all types of fabric constructions (woven, nonwoven and knit) have been modified by incorporation of the bound polyols. The most novel property is the thermal adaptability of the modified substrates to many climatic conditions. This adaptability is due to the high latent heat of the crosslinked polyols that function as phase change materials, the hydrophilic nature of the crosslinked polymer and its enhanced thermal conductivity. Other enhanced properties imparted to fabrics include flex and flat abrasion, antimicrobial activity, reduced static charge, resistance to oily soils, resiliency, wind resistance and reduced lint loss. Applications commercialized in the U.S. and Japan include sportswear and skiwear. Several examples of electric sets of properties useful for specific end uses are given. In addition, other uses are biomedical horticultural, aerospace, indoor insulation, automotive interiors and components and packaging material.

  4. Impact of Thermal Mass Oriented Measures Over CO2 Emissions Of a Thermally Insulated Lowrise Apartment Building in Izmir, Turkey

    Directory of Open Access Journals (Sweden)

    Mümine Gerçek

    2015-02-01

    Full Text Available Climate change has drawn the attention of many researchers and practitioners to focus on the methods to address the challenges in achieving low-carbon buildings and cities and in future developments. Nevertheless, few studies have explored the impacts of thermal mass applications for the lowest carbon emissions of building operational energy consumption. A comparative study of CO2 emissions due to different wall and floor compositions is presented in accordance with their lifespans for a hot-humid climate site. Aim of this study is to examine the relation between the energy oriented operations and carbon emissions of the building. Firstly, an existing low-rise building in İzmir is selected, then modelled in the dynamic simulation model software DesignBuilder v4 by synchronizing drawings with basic operational principles of the program. Furthermore, various influence factors of building envelope thermal characteristics are selected as follows: type, location, thickness and thermal specifications of materials used by keeping thermal conductivity value constant. At the end, the research presents remarkable influence of thermal mass oriented measures on reducing energy demands and carbon footprints.

  5. Coefficient of Thermal Diffusivity of Insulation Brick Developed from Sawdust and Clays

    Directory of Open Access Journals (Sweden)

    E. Bwayo

    2014-01-01

    Full Text Available This paper presents an experimental result on the effect of particle size of a mixture of ball clay, kaolin, and sawdust on thermal diffusivity of ceramic bricks. A mixture of dry powders of ball clay, kaolin of the same particle size, and sawdust of different particle sizes was mixed in different proportions and then compacted to high pressures before being fired to 950°C. The thermal diffusivity was then determined by an indirect method involving measurement of thermal conductivity, density, and specific heat capacity. The study reveals that coefficient of thermal diffusivity increases with decrease in particle size of kaolin and ball clay but decreases with increase in particle size of sawdust.

  6. A novel highly porous ceramic foam with efficient thermal insulation and high temperature resistance properties fabricated by gel-casting process

    Science.gov (United States)

    Yu, Jiahong; Wang, Guixiang; Tang, Di; Qiu, Ya; Sun, Nali; Liu, Wenqiao

    2018-01-01

    The design of super thermal insulation and high-temperature resistant materials for high temperature furnaces is crucial due to the energy crisis and the huge wasting. Although it is told that numerous studies have been reported about various of thermal insulation materials prepared by different methods, the applications of yttria-stabilized zirconia (YSZ) ceramic foams fabricated through tert-butyl alcohol (TBA)-based gel-casting process in bulk thermal isolators were barely to seen. In this paper, highly porous yttria-stabilized zirconia (YSZ) ceramic foams were fabricated by a novel gel-casting method using tert-butyl alcohol (TBA) as solvent and pore-forming agent. Different raw material ratio, sintering temperature and soaking time were all investigated to achieve optimal thermal insulation and mechanical properties. We can conclude that porosity drops gradually while compressive strength increases significantly with the rising temperature from 1000-1500°C. With prolonged soaking time, there is no obvious change in porosity but compressive strength increases gradually. All specimens have uniformly distributed pores with average size of 0.5-2μm and show good structural stability at high temperature. The final obtained ceramic foams displayed an outstanding ultra-low thermal conductivity property with only 200.6 °C in cold surface while the hot side was 1000 °C (hold 60 min to keep thermal balance before testing) at the thickness of 10 mm.

  7. Thermal processing of strained silicon-on-insulator for atomically precise silicon device fabrication

    International Nuclear Information System (INIS)

    Lee, W.C.T.; Bishop, N.; Thompson, D.L.; Xue, K.; Scappucci, G.; Cederberg, J.G.; Gray, J.K.; Han, S.M.; Celler, G.K.; Carroll, M.S.; Simmons, M.Y.

    2013-01-01

    Highlights: ► Strained silicon-on-insulator (sSOI) samples were flash-annealed at high temperature under ultra-high vacuum conditions. ► The extend of surface strain relaxation depends on the annealing temperature with no strain relaxation observed below 1020 °C. ► A 2 × 1 reconstructed surface with low defect density can be achieved. ► The annealed sSOI surface shows enhanced step undulations due to the unique energetics caused by surface strain. - Abstract: We investigate the ability to reconstruct strained silicon-on-insulator (sSOI) substrates in ultra-high vacuum for use in atomic scale device fabrication. Characterisation of the starting sSOI substrate using μRaman shows an average tensile strain of 0.8%, with clear strain modulation in a crosshatch pattern across the surface. The surfaces were heated in ultra-high vacuum from temperatures of 900 °C to 1100 °C and subsequently imaged using scanning tunnelling microscopy (STM). The initial strain modulation on the surface is observed to promote silicon migration and the formation of crosshatched surface features whose height and pitch increases with increasing annealing temperature. STM images reveal alternating narrow straight S A steps and triangular wavy S B steps attributed to the spontaneous faceting of S B and preferential adatom attachment on S B under biaxial tensile strain. Raman spectroscopy shows that despite these high temperature anneals no strain relaxation of the substrate is observed up to temperatures of 1020 °C. Above 1100 °C, strain relaxation is evident but is confined to the surface.

  8. Research on vacuum insulation for cryocables

    International Nuclear Information System (INIS)

    Graneau, P.

    1974-01-01

    Vacuum insulation, as compared with solid insulation, simplifies the construction of both resistive or superconducting cryogenic cables. The common vacuum space in the cable can furnish thermal insulation between the environment and the cryogenic coolant, provide electrical insulation between conductors, and establish thermal isolation between go- and return-coolant streams. The differences between solid and vacuum high voltage insulation are discussed, and research on the design, materials selection, and testing of vacuum insulated cryogenic cables is described

  9. Load Responsive MLI: Thermal Insulation with High In-Atmosphere and On-Orbit Performance, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Long term storage of cryopropellants with minimal loss is required for new Exploration spacecraft. Multi-Layer Insulation (MLI) is used to insulate cryotanks, but is...

  10. DYNAMICS MODEL OF MOISTURE IN PAPER INSULATION-TRANSFORMER OIL SYSTEM IN NON-STATIONARY THERMAL MODES OF THE POWER TRANSFORMER

    Directory of Open Access Journals (Sweden)

    V.V. Vasilevskij

    2016-06-01

    Full Text Available Introduction. An important problem in power transformers resource prognosis is the formation of moisture dynamics trends of transformer insulation. Purpose. Increasing the accuracy of power transformer insulation resource assessment based on accounting of moisture dynamics in interrelation with temperature dynamics. Working out of moisture dynamics model in paper insulation-transformer oil system in conjunction with thermodynamic model, load model and technical maintenance model. Methodology. The mathematical models used for describe the moisture dynamics are grounded on nonlinear differential equations. Interrelation moisture dynamics model with thermodynamic, load and technical maintenance models described by UML model. For confirming the adequacy of model used computer simulation. Results. We have implemented the model of moisture dynamics in power transformers insulation in interrelation with other models, which describe the state of power transformer in operation. The proposed model allows us to form detailed trends of moisture dynamics in power transformers insulation basing on monitoring data or power transformers operational factors simulation results. We have performed computer simulation of moisture exchange processes and calculation of transformer insulation resource for different moisture trends. Originality. The offered model takes into account moisture dynamics in power transformers insulation under the influence of changes of the power transformers thermal mode and operational factors. Practical value. The offered model can be used in power transformers monitoring systems for automation of resource assessment of oil-immersed power transformers paper insulation at different phase of lifecycle. Model also can be used for assessment of projected economic efficiency of power transformers exploitation in projected operating conditions.

  11. Gastric Calcifying Fibrous Tumour

    Directory of Open Access Journals (Sweden)

    Tan Attila

    2006-01-01

    Full Text Available Intramucosal gastric tumours are most commonly found to be gastrointestinal stromal tumours or leiomyomas (smooth muscle tumours; however, a variety of other uncommon mesenchymal tumours can occur in the stomach wall. A rare benign calcifying fibrous tumour is reported and the endoscopic appearance, ultrasound findings and morphology are documented. A review of the literature found only two similar cases.

  12. The Effect of Antioxidants on Suppression of Thermal Degradation of Insulation Material

    Science.gov (United States)

    Sagae, Masahiro; Sekii, Yasuo; Yoshino, Hiroto; Miyake, Koujirou

    Thermal degradation of EPDM and the effect of antioxidants on the degradation of EPDM was investigated. Using FT-IR (Fourier transform infrared spectrophotometer) micrometer the degree of degradation was analyzed. A new evaluation method of mapping measurement was introduced and showed to be very useful. Among oxidants studied, the phenolic antioxidant 4,4'-tiobis(3-methyl-6-tert.-Butyl phenol was confirmed to be useful. A synergetic effects between phenolic antioxidant 2,2'-methylene- bis (4-methyl-6-tert.buthylphenol) and sulfur type antioxidant, dilauryl thiodipropionate, was also confirmed. The temperature dependence of thermal degradation of EPDM was also analyzed.

  13. Analysis of the temperature dependence of the thermal conductivity of insulating single crystal oxides

    Directory of Open Access Journals (Sweden)

    E. Langenberg

    2016-10-01

    Full Text Available The temperature dependence of the thermal conductivity of 27 different single crystal oxides is reported from ≈20 K to 350 K. These crystals have been selected among the most common substrates for growing epitaxial thin-film oxides, spanning over a range of lattice parameters from ≈3.7 Å to ≈12.5 Å. Different contributions to the phonon relaxation time are discussed on the basis of the Debye model. This work provides a database for the selection of appropriate substrates for thin-film growth according to their desired thermal properties, for applications in which heat management is important.

  14. Thermally conductive, electrically insulating and melt-processable polystyrene/boron nitride nanocomposites prepared by in situ reversible addition fragmentation chain transfer polymerization

    International Nuclear Information System (INIS)

    Huang, Xingyi; Wang, Shen; Zhu, Ming; Yang, Ke; Jiang, Pingkai; Bando, Yoshio; Golberg, Dmitri; Zhi, Chunyi

    2015-01-01

    Thermally conductive and electrically insulating polymer/boron nitride (BN) nanocomposites are highly attractive for various applications in many thermal management fields. However, so far most of the preparation methods for polymer/BN nanocomposites have usually caused difficulties in the material post processing. Here, an in situ grafting approach is designed to fabricate thermally conductive, electrically insulating and post-melt processable polystyrene (PS)/BN nanosphere (BNNS) nanocomposites by initiating styrene (St) on the surface functionalized BNNSs via reversible addition fragmentation chain transfer polymerization. The nanocomposites exhibit significantly enhanced thermal conductivity. For example, at a St/BN feeding ratio of 5:1, an enhancement ratio of 1375% is achieved in comparison with pure PS. Moreover, the dielectric properties of the nanocomposites show a desirable weak dependence on frequency, and the dielectric loss tangent of the nanocomposites remains at a very low level. More importantly, the nanocomposites can be subjected to multiple melt processing to form different shapes. Our method can become a universal approach to prepare thermally conductive, electrically insulating and melt-processable polymer nanocomposites with diverse monomers and nanofillers. (paper)

  15. Thermal conductivity and Kapitza resistance of cyanate ester epoxy mix and tri-functional epoxy electrical insulations at superfluid helium temperature

    CERN Document Server

    Pietrowicz, S; Jones, S; Canfer, S; Baudouy, B

    2012-01-01

    In the framework of the European Union FP7 project EuCARD, two composite insulation systems made of cyanate ester epoxy mix and tri-functional epoxy (TGPAP-DETDA) with S-glass fiber have been thermally tested as possible candidates to be the electrical insulation of 13 T Nb$_{3}$Sn high field magnets under development for this program. Since it is expected to be operated in pressurized superfluid helium at 1.9 K and 1 atm, the thermal conductivity and the Kapitza resistance are the most important input parameters for the thermal design of this type of magnet and have been determined in this study. For determining these thermal properties, three sheets of each material with different thicknesses varying from 245 μm to 598 μm have been tested in steady-state condition in the temperature range of 1.6 K - 2.0 K. The thermal conductivity for the tri-functional epoxy (TGPAP-DETDA) epoxy resin insulation is found to be k=[(34.2±5.5).T-(16.4±8.2)]×10-3 Wm-1K-1 and for the cyanate ester epoxy k=[(26.8±4.8).T- (9...

  16. Experimental Study on Thermal Performance of Externally Insulated Walls of Intermittent Air-Conditioned Rooms in Summer in Hot Summer and Cold Winter Region, China

    Directory of Open Access Journals (Sweden)

    Yong Ding

    2014-01-01

    Full Text Available Now requirements for the thermal performance of building walls are based on the assumption that heat flux transfers in one direction through the wall. However, in Hot Summer and Cold Winter Region of China, the direction of heat flow in the wall not only changes with the seasons, but also changes in the same period of using. In this paper, dynamic thermal process of externally insulated walls in different air-conditioner’s running state in summer in Chongqing, China, was tested. The distribution characteristics of the outdoor and indoor air temperature and the surface and inner temperatures of the wall were analyzed and demonstrated. Based on the unsteady-state heat transfer theory, the study calculated and analyzed the distribution characteristics of the direction of the heat flux in the thermal process. Also the characteristics of insulation and heat preservation for walls under different air-conditioner’s running state were analyzed. It is shown that, in any air-conditioner’s running state, the direction of the heat flux through the wall is obviously dynamically changing. There is obvious difference in the thermal performance needs of the wall; that is, it has strong demand for thermal insulation in daytime and strong demand for heat dissipation during night time in summer.

  17. Thermal math model analysis of FRSI test article subjected to cold soak and entry environments. [Flexible Reuseable Surface Insulation in Space Shuttle Orbiter

    Science.gov (United States)

    Gallegos, J. J.

    1978-01-01

    A multi-objective test program was conducted at the NASA/JSC Radiant Heat Test Facility in which an aluminum skin/stringer test panel insulated with FRSI (Flexible Reusable Surface Insulation) was subjected to 24 simulated Space Shuttle Orbiter ascent/entry heating cycles with a cold soak in between in the 10th and 20th cycles. A two-dimensional thermal math model was developed and utilized to predict the thermal performance of the FRSI. Results are presented which indicate that the modeling techniques and property values have been proven adequate in predicting peak structure temperatures and entry thermal responses from both an ambient and cold soak condition of an FRSI covered aluminum structure.

  18. The Effects of Perlite Concentration and Coating Thickness of the Polyester Nonwoven Structures on Thermal and Acoustic Insulation and Also Electromagnetic Radiation Properties

    Directory of Open Access Journals (Sweden)

    Seyda EYUPOGLU

    2018-02-01

    Full Text Available In this study, the improvement of the thermal and acoustic insulation and also electromagnetic radiation properties of polyester (PET nonwoven fabric (NWF with 180 g/m2 weight was investigated. For this purpose, PET NWF was coated with perlite stone powder having 210 – 590 µm particle size using polyurethane (PU based coating. Five different concentrations from 1 to 5 % of perlite stone powder were applied to the surface of PET NWF having five different thicknesses. And then the effect of perlite concentration and its thickness to thermal, acoustic and electromagnetic radiation properties were studied. It was found that the addition of perlite stone powder increased the thermal and acoustic insulation properties of PET NWF. Furthermore, the addition of perlite stone powder does not affect the electromagnetic radiation properties of samples.DOI: http://dx.doi.org/10.5755/j01.ms.24.1.17562

  19. Silanization of boron nitride nanosheets (BNNSs) through microfluidization and their use for producing thermally conductive and electrically insulating polymer nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Seyhan, A.Tuğrul, E-mail: atseyhan@anadolu.edu.tr [Department of Materials Science and Engineering, Anadolu University - AU, Iki Eylul Campus, 26550 Eskisehir (Turkey); Composite Materials Manufacturing Science Laboratory (CMMSL), Research and Application Center of Civil Aviation (RACCA), Anadolu University - AU, Iki Eylul Campus, 26550 Eskisehir (Turkey); Göncü, Yapıncak; Durukan, Oya; Akay, Atakan; Ay, Nuran [Department of Materials Science and Engineering, Anadolu University - AU, Iki Eylul Campus, 26550 Eskisehir (Turkey)

    2017-05-15

    to make it possible to utilize them as promising filler constituent in manufacturing thermally conductive and electrically insulating polymer nanocomposites that could be considered as whole or a part of a heat-releasing device.

  20. Silanization of boron nitride nanosheets (BNNSs) through microfluidization and their use for producing thermally conductive and electrically insulating polymer nanocomposites

    Science.gov (United States)

    Seyhan, A. Tuğrul; Göncü, Yapıncak; Durukan, Oya; Akay, Atakan; Ay, Nuran

    2017-05-01

    to make it possible to utilize them as promising filler constituent in manufacturing thermally conductive and electrically insulating polymer nanocomposites that could be considered as whole or a part of a heat-releasing device.

  1. Method and Apparatus for Measuring Thermal Conductivity of Small, Highly Insulating Specimens

    Science.gov (United States)

    Miller, Robert A (Inventor); Kuczmarski, Maria A (Inventor)

    2013-01-01

    A method and apparatus for the measurement of thermal conductivity combines the following capabilities: 1) measurements of very small specimens; 2) measurements of specimens with thermal conductivity on the same order of that as air; and, 3) the ability to use air as a reference material. Care is taken to ensure that the heat flow through the test specimen is essentially one-dimensional. No attempt is made to use heated guards to minimize the flow of heat from the hot plate to the surroundings. Results indicate that since large correction factors must be applied to account for guard imperfections when specimen dimensions are small, simply measuring and correcting for heat from the heater disc that does not flow into the specimen is preferable.

  2. Photoluminescence Study of N-Type Thermal Conversion in Semi-Insulating GaAs.

    Science.gov (United States)

    1982-12-01

    generally concluded that since Ga and As vacancies are thermally generated, and may be occupied by amphoteric impuri- ties such as carbon, p-type or n...to as amphoteric impurities. A vacancy at a lattice site is termed an acceptor because the vacancy deprives the crystal of one electron per broken...rinsed, blown dry 22 and then soaked in hydrochloric acid for oxide removal. A dark field microscope was used to visually inspect each sample. Those

  3. OPTIMIZATION OF INTEGRATED THERMAL PROTECTION SYSTEM WITH VARIOUS INSULATING CORE OPTIONS (PREPRINT)

    Science.gov (United States)

    2015-10-19

    including Reusable Launch Vehicles (RLVs) [6, 7], miliary spaceplanes [8], spaceplanes for tourism [9], space trucks [10], suborbital package delivery...conduction capability. After the thermal analysis is nished the nodal temperatures will be saved into a result le. Then command "ETCHG,TTS" is used...temperature loadings Save time history of the nodal temperature distribution Parametrically model geometries Apply mechanical loadings Apply mechanical

  4. Inorganic Water Repellent Coatings for Thermal Protection Insulation on an Aerospace Vehicle

    Science.gov (United States)

    Fuerstenau, D. W.; Huang, P.; Ravikumar, R.

    1997-01-01

    The objective of this research was two-fold: first, to identify and test inorganic water-repellent materials that would be hydrophobic even after thermal cycling to temperatures above 600 C and, second, to develop a model that would link hydrophobicity of a material to the chemical properties of its constituent atoms. Four different materials were selected for detailed experimental study, namely, boron nitride, talc, molybdenite, and pyrophyllite, all of which have a layered structure made up of ionic/covalent bonds within the layers but with van der Waals bonds between the layers. The materials tested could be considered hydrophobic for a nonporous surface but none of the observed contact angles exceeded the necessary 90 degrees required for water repellency of porous materials. Boron nitride and talc were observed to retain their water-repellency when heated in air to temperatures that did not exceed 800 C, and molybdenite was found to be retain its hydrophobicity when heated to temperatures up to 600 C. For these three materials, oxidation and decomposition were identified to be the main cause for the breakdown of water repellency after repeated thermal cycling. Pyrophyllite shows the maximum promise as a potential water-repellent inorganic material, which, when treated initially at 900 C, retained its shape and remained hydrophobic for two thermal cycles where the maximum retreatment temperature is 900 C. A model was developed for predicting materials that might exhibit hydrophobicity by linking two chemical properties, namely, that the constituent ions of the compound belong to the soft acid-base category and that the fractional ionic character of the bonds be less than about 20 percent.

  5. Determination of deep levels in semi-insulating cadmium telluride by thermally stimulated current measurements

    International Nuclear Information System (INIS)

    Scharager, C.; Muller, J.C.; Stuck, R.; Siffert, P.

    1975-01-01

    Thermally stimulated current (TSC) measurements have been performed in high resistivity (rho approximately 10 7 ohms.cm) CdTe γ-ray detectors between 35 and 300K. The TSC curves have been analyzed by different methods, including those taking into account the retrapping of the carriers. The trap characteristics have been determined; especially three levels located at E(v)+0.13eV, E(v)+0.30eV and E(c)-0.55eV have been investigated [fr

  6. IMPACT ON THE APPLICATION OF INSULATION IN BUILDINGS TO ACHIEVE THERMAL COMFORT (A CASE STUDY: LAUSER OFFICE BUILDING IN BANDA ACEH

    Directory of Open Access Journals (Sweden)

    Nova Purnama Lisa

    2014-12-01

    Full Text Available From the results of research studies on the impact of the use of insulation in buildings, reducing solar radiation on buildings to improve indoor comfort by applying the Principles of radiation reduction in buildings naturally using insulation application that serves as an insulator against the building materials, use of thermal insulation in particular mounted on the roof of the building and the walls are located on second floor and the third floor Lauser office building, Calculate the cooling load for each room that was on second floor and the third floor based on the geographical location or position of the building, climate data, building material data , and the intensity of the spatial characteristics which include lighting, solar radiation, user activity and electrical appliances being used. The calculation is done with the help of Ecotech v.5, 2011. The location and position on the third floor of a building with a flat roof cast concrete, so that the heat absorbed by the platform, and two times greater than the amount of heat radiation is absorbed by the material in the direction of the light falling the sun is at an angle <30°C. The simulation results on the building with the addition of thermal insulation on all walls and the roof of the inside of the foam material ultrafolmadehid, without changing the model building and similar activities in accordance with the existing condition and the condition of the room using the air conditioner at a temperature of 18-26°C, indicating a decrease in cooling load signifinikan in any space reaches 40% of the total cooling load required on the lauser office building. Comparing the simulation results Ecotech temperature v.5 2011 with field measurements as a validation of the simulation results in order to achieve thermal comfort in buildings and can menggurangi use energy consumption in buildings and can be used as a reference in planning space-based conditioning systems energy efficient.

  7. Design of Inorganic Water Repellent Coatings for Thermal Protection Insulation on an Aerospace Vehicle

    Science.gov (United States)

    Fuerstenau, D. W.; Ravikumar, R.

    1997-01-01

    In this report, thin film deposition of one of the model candidate materials for use as water repellent coating on the thermal protection systems (TPS) of an aerospace vehicle was investigated. The material tested was boron nitride (BN), the water-repellent properties of which was detailed in our other investigation. Two different methods, chemical vapor deposition (CVD) and pulsed laser deposition (PLD), were used to prepare the BN films on a fused quartz substrate (one of the components of thermal protection systems on aerospace vehicles). The deposited films were characterized by a variety of techniques including X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The BN films were observed to be amorphous in nature, and a CVD-deposited film yielded a contact angle of 60 degrees with water, similar to the pellet BN samples investigated previously. This demonstrates that it is possible to use the bulk sample wetting properties as a guideline to determine the candidate waterproofing material for the TPS.

  8. Transparent thermal insulation for a fabrication hall of LHB, Salzgitter; Transparent gedaemmte Fertigungshalle bei LHB in Salzgitter

    Energy Technology Data Exchange (ETDEWEB)

    Galetzky, A. [Linke-Hofmann-Busch Waggon - Fahrzeug - Maschinen GmbH, Salzgitter (Germany); Goller, M. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany)

    1997-12-31

    Many industrial workshops in Germany were erected during the 40s and 50s, especially at the beginning of the economic boom. After more than 40 years, these facilities are in need of structural and production-technical modernization. A case in point is the carriage fabrication workshop of the Salzgitter-based company Linke-Hoffmann-Busch. The characteristic features of this type of building are large glazed areas, free uncontrolled ventilation and substantial height. Opportunities for energy-oriented and light-technical modernization are demonstrated at this Salzgitter workshop in exemplary form, the emphasis being on the use of solar energy components and, particularly, transparent thermal insulation. (orig.) [Deutsch] In der Bundesrepublik Deutschland gibt es viele Produktionshallen, die in den vierziger und fuenfziger Jahren, insbesondere zu Beginn des wirtschaftlichen Aufschwungs, errichtet wurden. Diese Hallen sind nach ueber vierzig Jahren sowohl aus baulichen als auch produktionstechnischen Gruenden sanierungsbeduerftig. Die Halle 1, Waggonneubau, der Linke-Hofmann-Busch GmbH in Salzgitter ist ein typischer Vertreter dieser Art von Hallen. Sie zeichnen sich durch grosse Verglasungsflaechen, freie unkontrollierte Lueftung und relativ grosse Bauhoehe aus. Exemplarisch werden an dieser Halle Moeglichkeiten einer energetischen und lichttechnischen Sanierung aufgezeigt, wobei der Einsatz von Solarenergiekomponenten und insbesondere der Transparenten Waermedaemmung besondere Beruecksichtigung erfaehrt. (orig.)

  9. An employee sews thermal insulation material on the back cover and heat shield of the Huygens probe

    Science.gov (United States)

    1997-01-01

    An employee in the Payload Hazardous Servicing Facility (PHSF) sews thermal insulation material on the back cover and heat shield of the Huygens probe during prelaunch processing, testing and integration in that facility. The Huygens probe and the Cassini orbiter being processed at KSC are the two primary components of the Cassini spacecraft, which will be launched on a Titan IVB/Centaur expendable launch vehicle from Cape Canaveral Air Station. Cassini will explore Saturn, its rings and moons for four years. The Huygens probe, designed and developed for the European Space Agency (ESA), will be deployed from the orbiter to study the clouds, atmosphere and surface of Saturn's largest moon, Titan. The orbiter was designed and assembled at NASA's Jet Propulsion Laboratory in California. Following postflight inspections, integration of the 12 science instruments not already installed on the orbiter will be completed. Then, the parabolic high-gain antenna and the propulsion module will be mated to the orbiter, followed by the Huygens probe, which will complete spacecraft integration. The Cassini mission is targeted for an Oct. 6 launch to begin its 6.7-year journey to the Saturnian system. Arrival at the planet is expected to occur around July 1, 2004.

  10. An employee sews thermal insulation material on the front heat shield of the Huygens probe in the PH

    Science.gov (United States)

    1997-01-01

    An employee in the Payload Hazardous Servicing Facility (PHSF) sews thermal insulation material on the front heat shield of the Huygens probe during prelaunch processing testing and integration in that facility, with the probe's back cover in the background. The Huygens probe and the Cassini orbiter being processed at KSC are the two primary components of the Cassini spacecraft, which will be launched on a Titan IVB/Centaur expendable launch vehicle from Cape Canaveral Air Station. Cassini will explore Saturn, its rings and moons for four years. The Huygens probe, designed and developed for the European Space Agency (ESA), will be deployed from the orbiter to study the clouds, atmosphere and surface of Saturn's largest moon, Titan. The orbiter was designed and assembled at NASA's Jet Propulsion Laboratory in California. Following postflight inspections, integration of the 12 science instruments not already installed on the orbiter will be completed. Then, the parabolic high-gain antenna and the propulsion module will be mated to the orbiter, followed by the Huygens probe, which will complete spacecraft integration. The Cassini mission is targeted for an Oct. 6 launch to begin its 6.7-year journey to the Saturnian system. Arrival at the planet is expected to occur around July 1, 2004.

  11. Fast numerical upscaling of heat equation for fibrous materials

    KAUST Repository

    Iliev, Oleg

    2010-08-01

    We are interested in numerical methods for computing the effective heat conductivities of fibrous insulation materials, such as glass or mineral wool, characterized by low solid volume fractions and high contrasts, i.e., high ratios between the thermal conductivities of the fibers and the surrounding air. We consider a fast numerical method for solving some auxiliary cell problems appearing in this upscaling procedure. The auxiliary problems are boundary value problems of the steady-state heat equation in a representative elementary volume occupied by fibers and air. We make a simplification by replacing these problems with appropriate boundary value problems in the domain occupied by the fibers only. Finally, the obtained problems are further simplified by taking advantage of the slender shape of the fibers and assuming that they form a network. A discretization on the graph defined by the fibers is presented and error estimates are provided. The resulting algorithm is discussed and the accuracy and the performance of the method are illusrated on a number of numerical experiments. © Springer-Verlag 2010.

  12. The measured study of natural weathering performance of reflective thermal insulation coating in hot-summer and warm-winter region

    Science.gov (United States)

    Xia, Zhao; Dafu, Weng; Jie, Gu; Binbin, Li

    2017-11-01

    In order to study the attenuation performance of solar direct reflectance of reflective thermal insulation coating under natural weathering, we conducted a measured study on five coatings with the built natural weathering platform. After the 18-month natural weathering experiments, the color of coating templets turn undertint or black with coating layer pulverized and fallen off, some of the templets starting to crack, fall off and go mouldy. Meanwhile, the reflectance ratio of reflective thermal insulation coating decreased significantly after 3 to 6 months, the degree of attenuation of the five templets is 2% to 28%. After 18 months’ exposure to the blazing sun, the most significant degree of attenuation reached 46%. The solar direct reflectance of coating templet of the same brand remained high as before after natural weathering with an initial high solar direct reflectance

  13. Laboratory test results on the thermal resistance of polyisocyanurate foamboard insulation blown with CFC-11 substitutes: A cooperative industry/government project

    Energy Technology Data Exchange (ETDEWEB)

    McElroy, D.L.; Graves, R.S.; Yarbrough, D.W.; Weaver, F.J.

    1991-09-01

    The fully halogenated chlorofluorocarbon gases (CFC-11 and CFC-12) are used as blowing agents for foam insulations for building and appliance applications. The thermal resistance per unit thickness of these insulations is greater than that of other commercially available insulations. Mandated reductions in the production of these chemicals may lead to less efficient substitutes and increase US energy consumption by one quad or more. This report describes laboratory thermal and aging tests on a set of industry-produced, experimental polyisocyanurate (PIR) laminate boardstock to evaluate the viability of hydrochlorofluorocarbons (HCFSs) as alternative blowing agents to chlorofluorcarbon-11 (CFC-11). The PIR boards were blown with five gases: CFC-11, HCFC- 123, HCFC-141b, and 50/50 and 65/35 blends of HCFC-123/HCFC-141b. These HCFC gases have a lower ozone depletion potential than CFC-11 or CFC-12. Apparent thermal conductivity (k) was determined from 0 to 50{degrees}C. Results on the laminate boards provide an independent laboratory check on the increase in k observed for field exposure in the Roof Thermal Research Apparatus (RTRA). The measured laboratory increase in k was between 8 and 11% after a 240-d field exposure in the RTRA. Results are reported on a thin-specimen, aging procedure to establish the long-term thermal resistance of gas-filled foams. These thin specimens were planed from the industry-produced boardstock foams and aged at 75 and 150{degrees}F for up to 300 d. The resulting k-values were correlated with an exponential dependency on (diffusion coefficient {times} time){sup {1/2}}/thickness and provided diffusion coefficients for air components into, and blowing agent out of, the foam. This aging procedure was used to predict the five-year thermal resistivity of the foams. The thin-specimen aging procedure is supported with calculations by a computer model for aging of foams. 43 refs., 33 figs., 25 tabs.

  14. Heat and Mass Transfer in a High-Porous Low-Temperature Thermal Insulation in Real Operating Conditions

    Directory of Open Access Journals (Sweden)

    Polovnikov Vyacheslav Yu.

    2015-01-01

    Full Text Available The results of numerical simulation of heat and mass transfer in a high-porous low-temperature insulation in conditions of insulation freezing, a moisture migration to the front of phase transition and a condensation forming on an outer contour of interaction were obtained. Values of heat leakage were established.

  15. Thermal conductivity of carbon felts, insulating materials with a high anisotropy; Conductivite thermique des feutres de carbone, isolants a forte anisotropie

    Energy Technology Data Exchange (ETDEWEB)

    Danes, F.E.; Bardon, J.P. [Centre National de la Recherche Scientifique, 44 - Nantes (France). Lab. de Thermocinetique

    1996-12-31

    Because of their high temperature resistance, carbon felts are used as thermal insulating materials for high temperature applications. The aim of this paper is to present a model that allows to calculate the thermal conductivity of felt fibers taking into account their high anisotropy and the contact resistance of fibers generated by the 3-D constriction phenomena which develop in fibers around each contact point. The study is divided in two parts: the first part concerns the bibliographic study of the different anisotropies of fibers and felts, while the second part presents the proposed conductivity model. (J.S.) 12 refs.

  16. Fibrous dysplasia and cherubism

    Directory of Open Access Journals (Sweden)

    Surajit Bhattacharya

    2015-01-01

    Full Text Available Fibrous dysplasia (FD is a non-malignant fibro-osseous bony lesion in which the involved bone/bones gradually get converted into expanding cystic and fibrous tissue. The underlying defect in FD is post-natal mutation of GNAS1 gene, which leads to the proliferation and activation of undifferentiated mesenchymal cells arresting the bone development in woven phase and ultimately converting them into fibro-osseous cystic tissue. Cherubism is a hereditary form of fibrous dysplasia in which the causative factor is transmission of autosomal dominant SH3BP2 gene mutation. The disease may present in two distinct forms, a less severe and limited monostotic form, and a more aggressive and more widespread polyostotic form. Polyostotic form may be associated with various endocrine abnormalities, which require active management apart from the management of FD. Management of FD is not free from controversies. While total surgical excision of the involved area and reconstruction using newer micro-vascular technique is the only definitive treatment available from the curative point of view, but this can be only offered to monostotic and very few polyostotic lesions. In polyostotic varieties on many occasions these radical surgeries are very deforming in these slow growing lesions and so their indication is highly debated. The treatment of cranio-facial fibrous dysplasia should be highly individualized, depending on the fact that the clinical behavior of lesion is variable at various ages and in individual patients. A more conservative approach in the form of aesthetic recontouring of deformed bone, orthodontic occlusal correction, and watchful expectancy may be the more accepted form of treatment in young patients. Newer generation real-time imaging guidance during recontouring surgery adds to accuracy and safety of these procedures. Regular clinical and radiological follow up is required to watch for quiescence, regression or reactivation of the disease process

  17. An experimental investigation on morphological, mechanical and thermal properties of date palm particles reinforced polyurethane composites as new ecological insulating materials in building

    Directory of Open Access Journals (Sweden)

    A. Oushabi

    2017-12-01

    Full Text Available The rigid polyurethane (PU with apparent density about 40 kg/m3 was prepared using commercial polyols and polyisocyanate. This reference petrochemical formulation was modified with natural and renewable components such as date palm particles (DPP. The goal of this investigation was to reduce the environmental impacts, and reduce the cost of the petroleum based polyurethane (PU by obtaining polyurethane/date palm particles (PU-DPP composites with the heat insulating and mechanical properties similar or better as in the case of the reference material (PU. The composites were prepared with different (DPP loading; 5%, 10%, and 20% (by weight. The results showed that heat insulating and mechanical properties of the (PU-DPP composites were comparable with those from reference petrochemical formulation (PU. On the other hand these mechanical and thermal performances are competitive with those of other insulating material available on the market. Hence the (PU-DPP is a good candidate for development of efficient, low cost, and safe insulating materials.

  18. Origin of the thermal expansion anomaly in layered Bi2X3 topological insulators: Ultrafast time-resolved pump-probe experiments and theory

    Science.gov (United States)

    Prakash, Gyan; Pal, Koushik; Jain, Manish; Waghmare, U. V.; Sood, A. K.

    2017-08-01

    Recent experiments on the thermal expansion of Sb2Te3 , a prototypical example of strong three-dimensional topological insulators, have shown an intriguing anomaly in the thermal expansion coefficient along the hexagonal axis (α ∥), which drops sharply to almost zero in a narrow range of temperature around ˜225 K. With no accompanying signatures in other properties, the origin of this anomaly is not understood. We present here femtosecond pump-probe differential reflectivity measurements on single crystals of Sb2Te3 as a function of temperature from 3 to 300 K to determine the temperature dependence of coherent optical and acoustic phonons along with the dynamics of the photoexcited carriers. We find clearly anomalous temperature dependence of the parameters associated with vibrational and electronic relaxation in the narrow temperature range of 200-250 K. Within first-principles density functional theoretical analysis, we show that the observed anomalies can be explained with a mechanism of formation of stacking faults stabilized by vibrational entropy above 200 K. As a similar anomaly in the thermal expansion is also observed in other chalcogenides in the same family, the proposed mechanism may also be applicable to these layered strong topological insulators.

  19. Vacuum foil insulation system

    Science.gov (United States)

    Hanson, John P.; Sabolcik, Rudolph E.; Svedberg, Robert C.

    1976-11-16

    In a multifoil thermal insulation package having a plurality of concentric cylindrical cups, means are provided for reducing heat loss from the penetration region which extends through the cups. At least one cup includes an integral skirt extending from one end of the cup to intersection with the penetration means. Assembly of the insulation package with the skirted cup is facilitated by splitting the cup to allow it to be opened up and fitted around the other cups during assembly.

  20. High-surface-area silica nanospheres (KCC-1) with a fibrous morphology

    KAUST Repository

    Polshettiwar, Vivek

    2010-08-02

    Fibrous nanosilica: A new family of high-surface-area silica nanospheres (KCC-1) have been prepared (see picture). KCC-1 features excellent physical properties, including high surface area, unprecedented fibrous surface morphology, high thermal (up to 950 °C) and hydrothermal stabilities, and high mechanical stability. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. The change of electric field and of some other insulating properties during isochronal annealing in thermally poled Ge-doped silica films

    DEFF Research Database (Denmark)

    Liu, Q.M.; Poumellec, B.; Braga, D.

    2005-01-01

    The secondary electron emission contrast between poled and unpoled regions in thermally poled Ge-doped silica films were measured according to different annealing temperatures and electron doses with electron acceleration energy of 5 keV. It is used for measuring the change on annealing of poling...... induced electric field and other insulating properties like electron traps population and conductivity in high field. Concerning the change of the contrast at low dose arising from the poling electric field, we show that this field begins to disappear at around 450 degrees C and is erased completely...

  2. Experimental study on the influence of different thermal insulation materials on the fire dynamics in a reduced-scale enclosure

    DEFF Research Database (Denmark)

    Leisted, Rolff Ripke; Sørensen, Martin X.; Jomaas, Grunde

    2017-01-01

    Four scaled (1:5) fire experiments with two identically classified types of commercially available sandwich panels incorporating either stone wool (SW) or poly-isocyanurate (PIR) foam as cores were conducted using a modified version of the ISO 13784-1 (Reaction to fire tests for sandwich panel...... in the fire behavior, depending on whether the enclosures were constructed of panels filled with SW or PIR insulation material. The mass losses of the insulation materials showed significant contribution from the PIR cores, regardless of fire load and the non-structural damage. The qualitative behavior...... in the full scale tests than in the scaled experiments. Therefore, it can be concluded that when the energy contribution from the core material remained negligible compared to the gas burner, the measured parameters matched quite well. Therefore, if the insulating core material does not dominate the fire...

  3. Theoretical and experimental investigation of acoustically induced vibrations in thermal insulation systems in air and helium at pressures up to 50 bars

    International Nuclear Information System (INIS)

    Bereczky, A.

    1985-06-01

    In High Temperature Gas-cooled Reactors thermal insulating systems are installed. The components of these systems are forced to mechanical vibrations by blower noise or pipe flow. In this paper the coupling between a liner insulation and a sound field has been investigated in air and helium at static pressure up to 50 bars and SPL up to 160 dB. In the theoretical part it is shown that, by applying the law of acoustic reciprocity, the response of a structure in a diffuse sound field can be calculated. The main parameter influencing the coupling between a sound field and a structure is the radiation efficiency of the structure. The highest degree of coupling occurs at the coincidence frequency. In the experimental part the radiation efficiency of a cover plate insulation was measured. Then the system was excited by narrow - or broadband noise, and the structure response was measured. The experimental results and theoretical predictions are in good agreement. From theory and experiment a modelling rule was derived. This rule shows under which conditions model test must be performed and how the results can be extrapolated to original reactor conditions. (orig.) [de

  4. Fibrous dysplasia of maxillary sinus

    OpenAIRE

    Tinoco, Paulo; Pereira, José Carlos Oliveira; Lourenço Filho, Rodolfo Caldas; Silva, Fabrício Boechat do Carmo; Ruela, Karol Pereira

    2009-01-01

    Introduction: The Fibrous Dysplasia is a benign bone disease, of slow growth and unknown etiology. The involvement of the craniofacial skeleton is not uncommon and, generally, produces facial asymmetries. Case Report: In this article we report the case of a patient with fibrous dysplasia occupying the entire left maxillary sinus with orbitary extension confirmed in the anatomopathological exam. Final Comments: The surgical treatment remains as the main therapeutic approach and the postoperati...

  5. Description and characterization of system for external insulation and retrofitting for Denmark with emphasis on the thermal performance

    Energy Technology Data Exchange (ETDEWEB)

    Rudbeck, C.; Svendsen, S.

    1999-06-01

    Lately there has been quite a large focus on retrofitting of the Danish buildings. The retrofitting of the building is done in order to solve one or more of the following problems: bad indoor climate, large use of energy for heating, insufficient durability or architectural unsatisfactory. In order to solve these problems insulation is often part of the retrofitting. As internal insulation has many disadvantages with regards to heat and moisture only systems for external insulation will be mentioned here. As there are several different systems for external insulation, each with different properties, there is a need for a systematic approach when the building designer chooses which system should be used on the building which is to be retrofitted. All 12 systems are described using a format that subdivides the information from the producers into description of the system, drawings showing the system and index-numbers regarding heat, moisture and economy. From the 12 systems descriptions it is seen that the investment cost for most of the system used for retrofitting and external insulation is almost equal. The parameters which separates the systems from each other is the maintenance cost and the cost of the heat transmission loss through the retrofitting-system. According to the calculations there is not one system which performs better than the others when changing the parameters. The choice of a system for retrofitting depends (as far as total economy is concerned) mainly on the maintenance cost (which is difficult to predict) and the energy cost. Likewise the life time of the retrofitting system does also influence the total economy. Apart from these three factors aesthetics should also be taken into account when choosing a retrofitting system but this aspect has not been dealt with in this report. (EHS)

  6. Adsorptive refrigeration system using a solar collector with a thermal insulating module; Sistema de refrigeracao adsortivo com a utilizacao de um coletor solar com anteparo otico

    Energy Technology Data Exchange (ETDEWEB)

    Gurgel, Jose Mauricio [Paraiba Univ., Joao Pessoa, PB (Brazil). Laboratorio de Energia Solar]. E-mail: gurgel@les.ufpb.br; Espinola Junior, Jose [Paraiba Univ., Joao Pessoa, PB (Brazil). Curso de Pos-Graduacao em Engenharia Mecanica; Andrade Filho, Luiz Simao [Paraiba Univ., Joao Pessoa, PB (Brazil). Centro de Tecnologia. Dept. de Tecnologia da Construcao Civil; Marcondes, Francisco [Paraiba Univ., Joao Pessoa, PB (Brazil). Escola de Engenharia. Dept. de Engenharia Mecanica

    2000-07-01

    The use of a solid adsorption cooling unit based on the binary silica gel/water couple constitute an very promising way to harness solar energy refrigeration purposes. Here is presented a mathematical model for the simulation of the system under several use conditions and it was shown coherent when compared with some experimental results. The several accomplished simulations showed the need to be projected a modulate reactor that can offer cooling easiness during the night period and shown the advantage of the use of an solar collector that can be easily opened and your thermal insulating module placed across the glass close the thermal radiation when the desorption process finish. The simulations results presented here shown an better COP for this configuration through an better cooling of the collector at night. (author)

  7. Characterization of waste of soda-lime glass generated from lapping process to reuse as filler in composite materials as thermal insulation

    Directory of Open Access Journals (Sweden)

    A. C. P. Galvão

    2015-09-01

    Full Text Available AbstractThe beneficiation plate process by soda-lime glass lapping in the glass industry generates, an untapped residue (waste. The waste of this material is sent to landfills, causing impact on the environment. This work aimed to characterize and evaluate the waste of soda-lime glass (GP lapping. After its acquisition, the GP was processed by grinding and sieving and further characterized by the chemical/mineralogical analysis (XRF, EDS and XRD, SEM morphology, particle size by laser diffraction, thermogravimetric analyses (TGA and DSC and thermophysical analyses. It was observed that the GP particles are irregular and micrometric with the predominant presence of Na, Si and Ca elements characteristic of amorphous soda-lime glass. The assessment of the chemical/mineralogical, morphological, thermophysical and thermal gravimetric characteristics of GP suggest its reuse as reinforcing fillers or filler in composite materials to obtain thermal insulation.

  8. An analysis of system pressure and temperature distribution in self-pressurizer of SMART and calculation of sizing of wet thermal insulator and pressurizer cooler

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yeon Moon; Lee, Doo Jeong; Yoon, Ju Hyun; Kim, Hwan Yeol [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-03-01

    To evaluate the amount of heat transfer from coolant to gas in reactor vessel heat transfer through the structure of pressurizer and evaporation/condensation on surface of liquid pool should be considered. And, also the heat exchange by pressurizer cooler and heat transfer to upper plate of reactor vessel should be considered. Thus, overall examinations on design variables which affect the heat transfer from coolant to gas are needed to maintain the pressurizer conditions at designed value for normal operation through heatup process. The major design variables, which affect system pressure and gas temperature during heatup, and the sizes of wet thermal insulator and pressurizer cooler, and volume of gas cylinder connected to pressurizer. A computer program is developed for the prediction of system pressure and temperature of pressurizer gas region with considering volume expansion of coolant and heat transfer from coolant to gas during heatup. Using the program, this report suggests the optimized design values of wet thermal insulator, pressurizer cooler, and volume of gas cylinder to meet the target conditions for normal operation of SMART. (author). 6 refs., 17 figs., 5 tabs.

  9. Environmental assessment of façade-building systems and thermal insulation materials for different climatic conditions

    OpenAIRE

    Sierra-Pérez, Jorge

    2016-01-01

    In the European Union, the building sector accounts for more than 40% of the total energy consumption and environmental impacts, representing the area with the greatest potential for intervention. In addition to the existing policies that promote energy efficiency in buildings, the embodied energy and the environmental impacts contained in the building materials should be considered. In the case of the construction of insulation façade systems, the environmental implications are different dep...

  10. The influence of insulation of walls of industrial objects on thermal regime at the heating system of gas infrared radiators

    OpenAIRE

    Nagornova Tatiana; Emelenchuk Vladimir

    2017-01-01

    The results of a numerical study of the process of heat transfer from the gas infrared emitters in the heated accommodation are represented. Simulation was conducted taking into account the heat withdrawal in the enclosing constructions and of heat exchange with the environment. The estimation of the average values of temperatures of air indoors in the dependence on the different intensity of heat withdrawal into the vertical walls is carried out (when the layer of insulation is present, and ...

  11. Chromium–niobium co-doped vanadium dioxide films: Large temperature coefficient of resistance and practically no thermal hysteresis of the metal–insulator transition

    Directory of Open Access Journals (Sweden)

    Kenichi Miyazaki

    2016-05-01

    Full Text Available We investigated the effects of chromium (Cr and niobium (Nb co-doping on the temperature coefficient of resistance (TCR and the thermal hysteresis of the metal–insulator transition of vanadium dioxide (VO2 films. We determined the TCR and thermal-hysteresis-width diagram of the V1−x−yCrxNbyO2 films by electrical-transport measurements and we found that the doping conditions x ≳ y and x + y ≥ 0.1 are appropriate for simultaneously realizing a large TCR value and an absence of thermal hysteresis in the films. By using these findings, we developed a V0.90Cr0.06Nb0.04O2 film grown on a TiO2-buffered SiO2/Si substrate that showed practically no thermal hysteresis while retaining a large TCR of 11.9%/K. This study has potential applications in the development of VO2-based uncooled bolometers.

  12. Fibrous dysplasia of maxillary sinus

    Directory of Open Access Journals (Sweden)

    Tinoco, Paulo

    2009-06-01

    Full Text Available Introduction: The Fibrous Dysplasia is a benign bone disease, of slow growth and unknown etiology. The involvement of the craniofacial skeleton is not uncommon and, generally, produces facial asymmetries. Case Report: In this article we report the case of a patient with fibrous dysplasia occupying the entire left maxillary sinus with orbitary extension confirmed in the anatomopathological exam. Final Comments: The surgical treatment remains as the main therapeutic approach and the postoperative follow-up is necessary due to this condition recurrent nature.

  13. Characterization of Min-K TE-1400 Thermal Insulation (Two-Year Gradient Stress Relaxation Testing Update)

    Energy Technology Data Exchange (ETDEWEB)

    Hemrick, James Gordon [ORNL; Lara-Curzio, Edgar [ORNL; King, James [ORNL

    2009-09-01

    Min-K 1400TE insulation material was characterized at Oak Ridge National Laboratory for use in structural applications under gradient temperature conditions. A previous report (ORNL/TM-2008/089) discusses the testing and results from the original three year duration of the project. This testing included compression testing to determine the effect of sample size and test specimen geometry on the compressive strength of Min-K, subsequent compression testing on cylindrical specimens to determine loading rates for stress relaxation testing, isothermal stress relaxation testing, and gradient stress relaxation testing. This report presents the results from the continuation of the gradient temperature stress relaxation testing and the resulting updated modeling.

  14. The influence of insulation of walls of industrial objects on thermal regime at the heating system of gas infrared radiators

    Directory of Open Access Journals (Sweden)

    Nagornova Tatiana

    2017-01-01

    Full Text Available The results of a numerical study of the process of heat transfer from the gas infrared emitters in the heated accommodation are represented. Simulation was conducted taking into account the heat withdrawal in the enclosing constructions and of heat exchange with the environment. The estimation of the average values of temperatures of air indoors in the dependence on the different intensity of heat withdrawal into the vertical walls is carried out (when the layer of insulation is present, and without it.

  15. Insulated pipe clamp design

    International Nuclear Information System (INIS)

    Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

    1980-01-01

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. 5 refs

  16. Cellulose Insulation

    Science.gov (United States)

    1980-01-01

    Fire retardant cellulose insulation is produced by shredding old newspapers and treating them with a combination of chemicals. Insulating material is blown into walls and attics to form a fiber layer which blocks the flow of air. All-Weather Insulation's founders asked NASA/UK-TAP to help. They wanted to know what chemicals added to newspaper would produce an insulating material capable of meeting federal specifications. TAP researched the query and furnished extensive information. The information contributed to successful development of the product and helped launch a small business enterprise which is now growing rapidly.

  17. A Numerical Study on Phonon Spectral Contributions to Thermal Conduction in Silicon-on-Insulator Transistor Using Electron-Phonon Interaction Model

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyung-sun; Koh, Young Ha; Jin, Jae Sik [Chosun College of Science and Technology, Gwangju (Korea, Republic of)

    2017-06-15

    The aim of this study is to understand the phonon transfer characteristics of a silicon thin film transistor. For this purpose, the Joule heating mechanism was considered through the electron-phonon interaction model whose validation has been done. The phonon transport characteristics were investigated in terms of phonon mean free path for the variations in the device power and silicon layer thickness from 41 nm to 177 nm. The results may be used for developing the thermal design strategy for achieving reliability and efficiency of the silicon-on-insulator (SOI) transistor, further, they will increase the understanding of heat conduction in SOI systems, which are very important in the semiconductor industry and the nano-fabrication technology.

  18. Cellulose as an adhesion agent for the synthesis of lignin aerogel with strong mechanical performance, Sound-absorption and thermal Insulation.

    Science.gov (United States)

    Wang, Chao; Xiong, Ye; Fan, Bitao; Yao, Qiufang; Wang, Hanwei; Jin, Chunde; Sun, Qingfeng

    2016-08-26

    The lignin aerogels that are both high porosity and compressibility would have promising implications for bioengineering field to sound-adsorption and damping materials; however, creating this aerogel had a challenge to adhesive lignin. Here we reported cellulose as green adhesion agent to synthesize the aerogels with strong mechanical performance. Our approach-straightforwardly dissolved in ionic liquids and simply regenerated in the deionized water-causes assembly of micro-and nanoscale and even molecule level of cellulose and lignin. The resulting lignin aerogels exhibit Young's modulus up to 25.1 MPa, high-efficiency sound-adsorption and excellent thermal insulativity. The successful synthesis of this aerogels developed a path for lignin to an advanced utilization.

  19. Development of polystyrene-geopolymer composite for thermal insulating material and its properties with special regards to flame resistance

    Science.gov (United States)

    Mucsi, G.; Szabó, R.; Nagy, S.; Bohács, K.; Gombkötő, I.; Debreczeni, Á.

    2017-10-01

    As a first part of the research, systematic experimental series were conducted in order to develop an appropriate fly ash-based geopolymer binder focusing on the workability of the paste. In these series, the NaOH molar ratio and water glass/NaOH ratio were investigated and the fineness of the fly ash was optimized presented in a recent paper. Based on these results the effect of metakaolin on the mechanical properties was studied. After developing the appropriate binder, experimental series were carried out using ground polystyrene as light aggregate in various concentration (from 30 V/V% up to 98 V/V%) and geopolymer as a binder in order to develop a heat insulating material. Compressive and flexural strength, specimen density, flammability, freeze-thaw resistance were determined in order to characterize the composite product. As a result of the experimental investigation, it was found that the flexural strength of the composite was found to be ~400 kPa which is as high as the original polystyrene heat insulating panel. Additionally, the flammability was much better than the original pure PS product, the sample was not ignited even at higher PS content (90%). Furthermore, the freeze-thaw resistance of the composite improved compared with the neat geopolymer.

  20. Thermal insulation field replacement for operating high temperature oil; Substituicao in situ do revestimento isolante termico de dutos que transportam oleo combustivel aquecido, sem paralisacao operacional

    Energy Technology Data Exchange (ETDEWEB)

    Maniero, Leo [Transpavi-Codrasa S.A., Sao Paulo, SP (Brazil); Oliver, Joao H. de L.; Pinto, Mucio E.A. C. [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

    2005-07-01

    The in Situ rehabilitation of the thermal isolated coating of heated pipelines required a technology development for material and equipment innovation, in such way, the coating rehabilitation was conducted keeping the continuous pipeline operation at 85 deg C. The new thermal coating is applied after the following services stages: dig the trench, purge the old thermal insulation, sand blasting of the steel pipe, application of a anticorrosive coating in the metallic substratum for continuous operation at 120 deg C, application of spacers around the steel pipe, fabrication of a polyethylene (PE) casing, cut and opening of the PE casing in its own longitudinal line, setting the PE casing over the spacers, closing of the PE casing by longitudinal thermoplastic welding with the automatic machine, boring a opening in the PE casing sidelong, injection of polyurethane foam inside of the PE casing, tampon the bores by thermoplastic weld, tying-in the PE casing with the next contiguous casing with electro fusion weld. The casing-bends are made from the PE casing cut in angles, like the specific project of each bend, the casing-bends are mounted outer the steel pipeline bends follows the same sequences of stages. (author)

  1. Fibrous histiocytoma of the trachea.

    Science.gov (United States)

    Sandstrom, R E; Proppe, K H; Trelstad, R L

    1978-09-01

    The light and electron microscopic features of a fibrous histiocytoma of the trachea that occurred in a 15-year-old Caucasian girl are presented. Emphasis is placed on the aggresive behavior and the importance of early recognition of the lesion in an unusual location.

  2. A High-Precision Adaptive Thermal Network Model for Monitoring of Temperature Variations in Insulated Gate Bipolar Transistor (IGBT Modules

    Directory of Open Access Journals (Sweden)

    Ning An

    2018-03-01

    Full Text Available This paper proposes a novel method for optimizing the Cauer-type thermal network model considering both the temperature influence on the extraction of parameters and the errors caused by the physical structure. In terms of prediction of the transient junction temperature and the steady-state junction temperature, the conventional Cauer-type parameters are modified, and the general method for estimating junction temperature is studied by using the adaptive thermal network model. The results show that junction temperature estimated by our adaptive Cauer-type thermal network model is more accurate than that of the conventional model.

  3. Bridging of shrinkage gaps by Exterior Thermal Insulation Composite Systems (ETICS); Zur Frage der Ueberbrueckung von Bewegungsfugen durch Waermedaemmverbundsysteme

    Energy Technology Data Exchange (ETDEWEB)

    Kuenzel, H. [Fraunhofer-Institut fuer Bauphysik, Holzkirchen (Germany)

    1998-10-01

    The bridging performance in respect to shrinkage gaps of ETICS is a subject of controversy. Practitioners point out good experience, calculative examinations, however, support the requirement of special tests prior to technical approval. Experiments at a half-timbered facade where an ETICS was applied to dry-out the wall confirm their bridging ability during the shrinkage of the wooden studs. Therefore a special bridging test is generally not necessary for an insulation thickness of 80 mm or more. (orig.) [Deutsch] Zur Frage der Ueberbrueckung von Bewegungsfugen durch Waermedaemmverbundsysteme gibt es unterschiedliche Meinungen: Die Anwender weisen auf gute Erfahrungen in der Praxis hin, rechnerische Untersuchungen lassen hingegen eine spezielle Ueberpruefung fuer zweckmaessig erscheinen, die bisher bei der Zulassung solcher Systeme gefordert worden ist. Untersuchungen an einem Fachwerk-Versuchshaus mit nachtraeglich aufgebrachtem Waermedaemmverbundsystem bestaetigen dessen fugenueberbrueckende Eigenschaft beim Schwinden des Fachwerkholzes. Demnach ist bei Daemmschichtdicken von mindestens 80 mm ein Nachweis der Fugenueberbrueckungs-Faehigkeit generell nicht erforderlich. (orig.)

  4. Recycled-PET fibre based panels for building thermal insulation: environmental impact and improvement potential assessment for a greener production.

    Science.gov (United States)

    Ingrao, Carlo; Lo Giudice, Agata; Tricase, Caterina; Rana, Roberto; Mbohwa, Charles; Siracusa, Valentina

    2014-09-15

    A screening of Life Cycle Assessment for the evaluation of the damage arising from the production of 1 kg of recycled Polyethylene Terephthalate (RPET) fibre-based panel for building heat insulation was carried out according to the ISO 14040:2006 and 14044:2006. All data used were collected on site based on observations during site visits, review of documents and interviews with technical personnel and management. These data were processed by using SimaPro 7.3.3, accessing the Ecoinvent v.2.2 database and using the Impact 2002+ method. The study showed damage to be equal to 0.000299 points mostly due to the: 1) PET thermo-bonding fibre supply from China by means of a freight-equipped intercontinental aircraft; 2) production of bottle-grade granulate PET; 3) medium voltage electricity consumption during the manufacturing of RPET fibre panel. It was also highlighted that there were environmental benefits due to recycling through mainly avoiding significant emissions and reduced resource consumption. An improvement assessment was carried out to find solutions aimed at reducing the damage coming from the most impacting phases. Furthermore, the environmental impacts due to the production of the analysed RPET fibre-based panel were compared to other materials with the same insulating function, such as polystyrene foam, rock wool and cork slab. Finally, the environmental benefits of the recycling of PET bottles for flake production were highlighted compared to other treatment scenarios such as landfill and municipal incineration. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Simulation and Experimental Determination of Technological Liquid Molding Parameters of Tubing Basalt Insulation

    Directory of Open Access Journals (Sweden)

    Yu. V. Badanina

    2015-01-01

    Full Text Available The article is dedicated to one of the most important and urgent tasks in mechanical engineering development - the creation of low-density and environmentally-friendly thermoinsulation from available cheap basalt fibers for products to operate at temperatures up to 700°C.One of the most effective applications of such thermo-insulation is to develop and provide highly porous coatings from short basalt fibers by liquid filtration for tubing (T to supply superheated up to 420° C steam under pressure of 35 MPa in the deep layers with severe highviscosity oil. Tubing with the short low-density basalt insulation can be used for a greater depth than the vacuum-insulated tubing, which are also called "thermo-cases", and do not fully meet business needs for long-term reliability of oil vacuum tubes, too large mass per unit length of their design and, as a consequence, the impossibility to use such pipes for deep wells.The aim of the work is to simulate a liquid filtration process of short fibers and determine technological parameters of producing thermal insulation coatings of tubing pipes from basalt fibers and mineral binder shaped as cylinders and cylindrical shells. The paper proposes a mathematical model of free filtration deposition of short fibers from liquid slurry, which describes dynamics of creating thermal insulation products and allows us to determine the rational parameters of their manufacturing process. It shows methods to improve the products quality while forming the thermal insulation by filtration through additional vacuum deposition of a filtrate chamber and the final prepressing of sediment layer, giving dimensions and shape to the final product.The paper defines a prescription hydro mass composition. It shows that to increase the compressive strength of highly fibrous rings and cylindrical shells it is necessary to use based on oxide А12O3 5-7% by weight mineral binder, which fixes basalt fibers in places of their contacts. It

  6. Compressibility of air in fibrous materials

    DEFF Research Database (Denmark)

    Tarnow, Viggo

    1996-01-01

    The dynamic compressibility of air in fibrous materials has been computed for two assumed configurations of fibers which are close to the geometry of real fiber materials. Models with parallel cylinders placed in a regular square lattice and placed randomly are treated. For these models...... the compressibility is computed approximately from the diameter and mean distances between cylinders. This requires calculation of the air temperature, which is calculated for cylinders in a regular lattive by the Wigner-Seitz cell approximation. In the case of random placement, the calculation is done by a summation...... over thermal waves from all fibers, and by a self-consistent procedure. Figuren of the compressibility in the frequency range 10-100 000 Hz, are given for diameter of the cylinders of 6.8 µm, and mean distances between them from 50 to 110 µm, which corresponds to glass wool with a density of 40 to 16...

  7. Optimization of transport thermal insulation and heat storage systems in consideration of thermal and hygric damage to the building. Final report; Optimierung von TWD-Speichersystemen unter Beachtung der Bauschadensfreiheit (thermisch-hygrisch). Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, U.

    2001-01-01

    Thermal and hygric loads and damage of transparent thermal insulation systems were investigated using the FEM code Abaqus, which enables 2D calculations of thermal stresses and strains in layered structures (e.g. external walls). The influence of hygric swelling and shrinking had to be implemented separately. In addition to the calculations, two variants were investigated experimentally in order to validate the theoretical results. In the case of climate-induced thermal and hygromechanical loads, the dynamic heat and moisture transport processes must be taken into account. [German] Es war das Ziel des ausgefuehrten Forschungsprojektes, TWD-bestueckte Fassadenelemente hinsichtlich thermisch-hygrisch verursachter Belastungen und Schaeden zu untersuchen. Zu diesem Zweck fand das FEM-Programm Abaqus Verwendung. Es gestattet zweidimensionale thermisch verursachte Spannungs-Dehnungs-Berechnungen von geschichteten Strukturen (z.B. Fassaden). Der Einfluss des hygrischen Quellens und Schwindens musste allerdings gesondert implementiert werden. Neben den Berechnungen sind zwei Ausfuehrungsvarianten experimentell untersucht worden, um durch die Ergebnisse die Resultate der Berechnungen abzusichern. Fuer die klimatisch verursachten thermo- und hygromechanischen Belastungen muessen die dynamischen Waerme- und Feuchtetransportprozesse ins Blickfeld gerueckt werden. (orig.)

  8. Optimization of transport thermal insulation and heat storage systems in consideration of thermal and hygric damage to the building. Pt. 2. Final report; Optimierung von TWD-Speichersystemen unter Beachtung der Bauschadensfreitheit (thermisch-hygrisch). T. 2. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, U.; Mueller, K.

    2002-01-01

    Thermal and hygric loads and damage of transparent thermal insulation systems were investigated using the FEM code Abaqus, which enables 2D calculations of thermal stresses and strains in layered structures (e.g. external walls). The influence of hygric swelling and shrinking had to be implemented separately. In addition to the calculations, two variants were investigated experimentally in order to validate the theoretical results. In the case of climate-induced thermal and hygromechanical loads, the dynamic heat and moisture transport processes must be taken into account. [German] Es war das Ziel des ausgefuehrten Forschungsprojektes, TWD-bestueckte Fassadenelemente hinsichtlich thermisch-hygrisch verursachter Belastungen und Schaeden zu untersuchen. Zu diesem Zweck fand das FEM-Programm Abaqus Verwendung. Es gestattet zweidimensionale thermisch verursachte Spannungs-Dehnungs-Berechnungen von geschichteten Strukturen (z.B. Fassaden). Der Einfluss des hygrischen Quellens und Schwindens musste allerdings gesondert implementiert werden. Neben den Berechnungen sind zwei Ausfuehrungsvarianten experimentell untersucht worden, um durch die Ergebnisse die Resultate der Berechnungen abzusichern. Fuer die klimatisch verursachten thermo- und hygromechanischen Belastungen muessen die dynamischen Waerme- und Feuchtetransportprozesse ins Blickfeld gerueckt werden. (orig.)

  9. Thickness calculation software of the thermal insulation in facilities using thermal solar energy; Software para el calculo de espesores del aislante termico en instalaciones de aprovechamiento de energia solar termica

    Energy Technology Data Exchange (ETDEWEB)

    Portillo Jimenez, Canek [Universidad Autonoma de Sinaloa, Culiacan, Sinaloa (Mexico)]. E-mail: cnk@uas.uasnet.mx

    2010-11-15

    It is presented a software application for calculating the thickness of the thermal insulation used in various facilities where there are thermal systems using solar energy. The software facilitates the calculation of the thermal cover thickness over components such as pipes (flat or round), storage and other devices that require thermal protection, installed in outdoors or indoors. The software was programmed in Visual Basic by following the technical specifications of the current regulations in the field. Application examples are performed, obtaining certain results that are discussed briefly. [Spanish] Se presenta un software de aplicacion para el calculo de los espesores de los aislantes termicos, utilizados en diferentes instalaciones donde existen sistemas de aprovechamiento termico de energia solar. El software facilita el calculo del grosor del recubrimiento termico en componentes tales como: tuberias (planas o circulares), depositos acumuladores y otros aparatos que necesiten proteccion termica, instalados en exteriores o en interiores. El software fue programado en Visual Basic siguiendo las especificaciones tecnicas de la normatividad vigente en la materia. Se realizan ejemplos de aplicacion, donde se obtienen ciertos resultados de los cuales se hace una breve discusion.

  10. Low conductive support for thermal insulation of a sample holder of a variable temperature scanning tunneling microscope

    Czech Academy of Sciences Publication Activity Database

    Hanzelka, Pavel; Vonka, J.; Musilová, Věra

    2013-01-01

    Roč. 84, č. 8 (2013), 085103:1-6 ISSN 0034-6748 R&D Projects: GA MŠk ED0017/01/01; GA TA ČR TE01020233 Institutional support: RVO:68081731 Keywords : Thermal conductiviy * Scanning tunneling microscope Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.584, year: 2013

  11. Fibrous dysplasia in paranasal cavities.

    Science.gov (United States)

    Simovic, S; Klapan, I; Bumber, Z; Bura, M

    1996-01-01

    Presentation is made of 2 boys and a girl with fibrous dysplasia involving the frontal and ethmoidal sinuses and the maxilla. This tumor-like growth of the bone was not restricted to the sinus alone but expanded to the orbit, adjacent sinus, skull base and infratemporal or pterygoid fossa. In such cases, surgical therapy is the treatment of choice, with maximal preservation of healthy tissue and avoidance of major devastations that may result in undesired cosmetic defects. The etiology of the disease is still unknown. However, it should be emphasized that all 3 patients had suffered an injury to the adjacent bony structures at various time points preceding the disease manifestation. That is why we are inclined to believe that trauma might be a factor responsible for the onset of fibrous dysplasia.

  12. Creep of fibrous composite materials

    DEFF Research Database (Denmark)

    Lilholt, Hans

    1985-01-01

    Models are presented for the creep behaviour of fibrous composite materials with aligned fibres. The models comprise both cases where the fibres remain rigid in a creeping matrix and cases where the fibres are creeping in a creeping matrix. The treatment allows for several contributions to the cr......Models are presented for the creep behaviour of fibrous composite materials with aligned fibres. The models comprise both cases where the fibres remain rigid in a creeping matrix and cases where the fibres are creeping in a creeping matrix. The treatment allows for several contributions...... such as Ni + W-fibres, high temperature materials such as Ni + Ni3Al + Cr3C2-fibres, and medium temperature materials such as Al + SiC-fibres. For the first two systems reasonable consistency is found for the models and the experiments, while for the third system too many unquantified parameters exist...

  13. MRI of angiomatoid fibrous histiocytoma

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chao-Shiang; Chen, Wei-Tsung; Chen, Ran-Chou; Tu, Hsing-Yang [Taipei Municipal Jen-Ai Hospital, Department of Radiology, Taipei (Taiwan); Chan, Wing P. [Taipei Medical University, Department of Radiology, School of Medicine, Taipei (Taiwan); Taipei Municipal Wan-Fang Hospital, Department of Radiology, Taipei (Taiwan); Chang, Chih-Peng [Taipei Municipal Jen-Ai Hospital, Department of Orthopedic Surgery, Taipei (Taiwan); Shih, Li-Sun [Taipei Municipal Jen-Ai Hospital, Department of Pathology, Taipei (Taiwan)

    2004-10-01

    Angiomatoid fibrous histiocytoma is a rare soft tissue tumor of low-grade malignancy. We present the case of a 32-year-old man who complained of soreness and numbness over his left arm and hand over the previous 2 months and of having a palpable mass over his left upper back for 4 years. Magnetic resonance imaging (MRI) showed an intramuscular soft tissue mass in the left scapular region. The tumor mass was seen to have multiple cystic components with fluid-fluid levels. Histological examination showed multiple cystic spaces filled with blood lakes and hemosiderin deposits in the solid part of the tumor. After the initial surgery, the patient had local recurrences over 2.5 years. The immunohistochemical study at the second surgery showed that the recurrent tumor was strongly positive for the histiocytic marker CD68, and the myoid trait desmin. Histological diagnosis was compatible with angiomatoid fibrous histiocytoma. (orig.)

  14. Insulation Reformulation Development

    Science.gov (United States)

    Chapman, Cynthia; Bray, Mark

    2015-01-01

    The current Space Launch System (SLS) internal solid rocket motor insulation, polybenzimidazole acrylonitrile butadiene rubber (PBI-NBR), is a new insulation that replaced asbestos-based insulations found in Space Shuttle heritage solid rocket boosters. PBI-NBR has some outstanding characteristics such as an excellent thermal erosion resistance, low thermal conductivity, and low density. PBI-NBR also has some significant challenges associated with its use: Air entrainment/entrapment during manufacture and lay-up/cure and low mechanical properties such as tensile strength, modulus, and fracture toughness. This technology development attempted to overcome these challenges by testing various reformulated versions of booster insulation. The results suggest the SLS program should continue to investigate material alternatives for potential block upgrades or use an entirely new, more advanced booster. The experimental design was composed of a logic path that performs iterative formulation and testing in order to maximize the effort. A lab mixing baseline was developed and documented for the Rubber Laboratory in Bldg. 4602/Room 1178.

  15. Insulated pipe clamp design

    International Nuclear Information System (INIS)

    Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

    1980-01-01

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. The design considerations and methods along with the development tests are presented. Special considerations to guard against adverse cracking of the insulation material, to maintain the clamp-pipe stiffness desired during a seismic event, to minimize clamp restraint on the pipe during normal pipe heatup, and to resist clamp rotation or spinning on the pipe are emphasized

  16. Thermal renovation of a 'Gruenderzeit'-house by means of a capillary active inside insulation. Final report; Hygrisch motivierter Waermeschutz. Thermische Sanierung eines Gruenderzeithauses mit einer kapillaraktiven Calciumsilikatinnendaemmung. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Haeupl, P.; Grunewald, J.; Fechner, H.; Jurk, K.; Martin, R.

    1999-04-01

    Energy savings are still the best form of alternative energy. While newly-built houses generally meet at least the heat loss protection codes for wintertime, the thermal improvement of the old building stock is a nation-wide economically relevant energy conservation, despite the fact that modern user habits and demands enforce such measurements anyway. However, the old construction is to be changed only asmuch as no damages can occur. New heating systems, insulation between the rafters in the roof section, additional insulation of the basement ceiling, and above all, heat-loss-protected and air-tight windows often lead to surface condensation and mould formation on the walls. If the outside wall is to be insulated, but the facade to be kept in its original appearance, then only an interior insulation is possible for a thermal retrofitting. The main goal of this project is to realise the idea of a gently capillary active inside insulation without additional vapour barrier for a reference building, to control it with measurement technology over a period of at least two winter- and summertimes, and to quantify the heat- and moisture content by means of a numerical simulation. As specific object with a worth-preserving facade for the application of the above-mentioned inside insulation was chosen, together with the City Redeveloping Association Dresden, a typical 'Gruenderzeit'-apartment house, built 1895 in Dresden-Neustadt, and extensively renovated from 1995 to 97. The main emphasis of the thermal retrofitting lies in the application of a 30 mm strong Calcium-Silicate slab along the inside of the exterior wall of the street facade. This wall made of brick is covered with square sandstone blocks all over the ground level and covered with a clinker layer typical for that time. With this project, the proof of a thermally sufficient and hygrically unproblematic retrofitting of an old building structure by means of inside insulation is given, and the foundation

  17. Effects of Sodium Bicarbonate Content and Vulcanization Method on Properties of NBR/PVC Thermal Insulator Foam

    OpenAIRE

    P. Suriyachai; N. Thavarungkul; P. Sae-oui

    2010-01-01

    In this research sodium bicarbonate (NaHCO3) was introduced to generate carbon dioxide gas (CO2) to the existing nitrogen gas (N2) of elastomeric foam, to lower thermal conductivity (K). Various loadings of NaHCO3 (0 to 60 phr) were added into the azodicarbonamide (AZC)-containing compound and its properties were then determined. Two vulcanization methods, i.e., hot air and infrared (IR), were employed and compared in this study. Results revealed that compound viscosity tended to increase sli...

  18. Enhanced mechanical and thermal properties of regenerated cellulose/graphene composite fibers.

    Science.gov (United States)

    Tian, Mingwei; Qu, Lijun; Zhang, Xiansheng; Zhang, Kun; Zhu, Shifeng; Guo, Xiaoqing; Han, Guangting; Tang, Xiaoning; Sun, Yaning

    2014-10-13

    In this study, a wet spinning method was applied to fabricate regenerated cellulose fibers filled with low graphene loading which was systematically characterized by SEM, TEM, FTIR and XRD techniques. Subsequently, the mechanical and thermal properties of the resulting fibers were investigated. With only 0.2 wt% loading of graphene, a ∼ 50% improvement of tensile strength and 25% enhancement of Young's modulus were obtained and the modified Halpin-Tsai model was built to predict the mechanical properties of composite fibers. Thermal analysis of the composite fibers showed remarkably enhanced thermal stability and dynamic heat transfer performance of graphene-filled cellulose composite fiber, also, the presence of graphene oxide can significantly enhance the thermal conductivity of the composite fiber. This work provided a facile way to improve mechanical and thermal properties of regenerated cellulose fibers. The resultant composite fibers have potential application in thermal insulation and reinforced fibrous materials. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Effect of façade impregnation on feasibility of capillary active thermal internal insulation for a historic dormitory – A hygrothermal simulation study

    DEFF Research Database (Denmark)

    Finken, Gholam Reza; Bjarløv, Søren Peter; Peuhkuri, Ruut Hannele

    2016-01-01

    Internal insulation of external walls is known to create moisture performance challenges due to increased moisture levels and condensation risk on the cold side of the insulation. Capillary active/hydrophilic insulations have been introduced to solve these moisture problems, since they are able...... to transport liquid moisture to the inner surface and enable it to dry. Experience with this insulation type is rare in Denmark. In hygrothermal 1D computer simulations, several more or less capillary active insulation systems (AAC, calcium silicate, IQ-Therm) in various thicknesses (30–150 mm) have been....... A moisture safe construction was only achieved when exterior façade impregnation shielding against driving rain was added. The best system showed acceptable relative humidity values both behind the insulation and on the interior surface, a significant increase in minimum temperature on the interior surface...

  20. Thermal Performance of Aged and Weathered Spray-On Foam Insulation (SOFI) Materials Under Cryogenic Vacuum Conditions (Cryostat-4)

    Science.gov (United States)

    2008-01-01

    The NASA Cryogenics Test Laboratory at Kennedy Space Center conducted long-term testing of SOFI materials under actual-use cryogenic conditions with Cryostat-4. The materials included in the testing were NCFI 24-124 (acreage foam), BX-265 (close-out foam, including intertank flange and bipod areas), and a potential alternate material, NCFI 27-68, (acreage foam with the flame retardant removed). Specimens of these materials were placed at two locations: a site that simulated aging (the Vehicle Assembly Building [VAB]) and a site that simulated weathering (the Atmospheric Exposure Test Site [beach site]). After aging/weathering intervals of 3, 6, and 12 months, the samples were retrieved and tested for their thermal performance under cryogenic vacuum conditions with test apparatus Cryostat-4.

  1. Fibrous dysplasia of the ethmoid sinus.

    Science.gov (United States)

    Tsai, Tung-Lung; Ho, Ching-Yin; Guo, Yuan-Ching; Chen, Winby; Lin, Ching-Zong

    2003-02-01

    Although craniofacial bone is the second common site of fibrous dysplasia involvement, it is rarely found in the paranasal sinus. Among fibrous dysplasia of the head and neck, the maxilla and mandible are the most frequent sites to be involved. Fibrous dysplasia becomes dormant in adolescence and early adult life and is more common in female. It is one of the fibrous osseous lesions and should be differentiated from osteoma and ossifying fibroma. Radiographically, fibrous dysplasia showed "groundglass" bone appearance on CT scans with bone window. Histopathologically, it presents woven-type bone embedded in a cellular fibrous stroma without osteoblastic rimming. We presented a case of 25-year-old female with fibrous dysplasia in her right side ethmoid sinus. She visited to us with the chief complaint of right side headache since adolescence. The lesion was removed by endoscopic sinus surgery and pathology proved fibrous dysplasia. The patient was free of headache after operation. The advance of endoscopic sinus surgical technique, makes it an optimal method for the pathological diagnosis and treatment to avoid the cosmetic problems caused by external approach in limited paranasal sinus fibrous osseous lesions.

  2. Sound insulation properties of structure designed from apparel cutting waste

    OpenAIRE

    Jordeva, Sonja; Tomovska, Elena; Trajković, Dušan; Popeski-Dimovski, Riste; Zafirova, Koleta

    2015-01-01

    In this paper an insulation structure from apparel cutting waste was designed and its sound insulation properties were investigated. Shredded polyester apparel cuttings were used as the raw material for an insulation structure. The obtained results show that the insulation structure made from apparel cutting waste has good sound absorption compared to standard sound and thermal insulators. The average sound absorption of the samples was from 54.7% to 74.7%, for a frequency range of 250-2000Hz...

  3. Topological insulators

    CERN Document Server

    Franz, Marcel

    2013-01-01

    Topological Insulators, volume six in the Contemporary Concepts of Condensed Matter Series, describes the recent revolution in condensed matter physics that occurred in our understanding of crystalline solids. The book chronicles the work done worldwide that led to these discoveries and provides the reader with a comprehensive overview of the field. Starting in 2004, theorists began to explore the effect of topology on the physics of band insulators, a field previously considered well understood. However, the inclusion of topology brings key new elements into this old field. Whereas it was

  4. Thermal support elements (TTE) made of high-tensile fibre-reinforced material and integrated vacuum-insulation panels (VIP) - Final report; Thermotragelemente (TTE) aus hochfestem Faserverbundstoff und integrierten Vakuumisolationspaneelen (VIP) - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Motavalli, M.; Ghazi Wakili, K.; Gsell, D.; Herwig, A.

    2008-07-01

    In this project, the static and thermal characteristics of the balcony connection element TTE (load carrying thermo-element) of the Hitek Construction Company AG were investigated. The TTE is an innovative element, which minimises thermal bridges that always exist in the vicinity of balcony connections. The concept of the element relies of the ability of fibre reinforced composites with superior thermal and mechanical characteristics to transfer the high mechanical loads from the balcony, through the layer of insulation, to the building. From a mechanical point-of-view, only very limited use of fibre reinforced composites has been seen for this type of construction application, therefore necessitating a detailed investigation of the element. In a first step, component tests of the individual load carrying elements were carried out, in which the elements showed an entirely satisfactory short-term behaviour. Furthermore, several assembly tests were carried out whereby parts of the balcony were reproduced, loaded and observed over longer term. During the investigations it was seen that very high stresses occur in the compression zone of the concrete deck and that the element must be modified in the future. From a thermal point-of-view, the TTE element offers a considerable improvement as compared with concrete decks without a thermal discontinuity. The thermal properties of the TTE element can be considered similar to or slightly better than other thermally discontinuous systems with the same load carrying capacity. This is understandable, since a thicker insulating layer with a thermal resistance of 2.5 m{sup 2} K/W was partially replaced through a thinner, yet more efficient insulation with a thermal resistance of 1.9 m{sup 2} K/W. Moreover, the glass fibre reinforced polymer has a larger thermal resistance than steel. The results obtained from the mechanical and thermal tests point to the need for further optimisation of the TTE element. It has been seen, however

  5. Building energy efficiency and its effect on the frost insulation

    Energy Technology Data Exchange (ETDEWEB)

    Airaksinen, M., Email: miimu.airaksinen@vtt.fi

    2012-06-15

    The energy efficiency of new buildings has improved significantly and is still improving. As the thermal insulation of the building envelope increases other properties and 'thumb' values might also change. Especially when the thermal transmittance (U-value) of the slab on the ground decreases, the frost insulation should also be reconsidered. The aim of this study is to find out how the frost insulation changes when the base floor and foundation insulation change. (orig.)

  6. Composite fibrous glaucoma drainage implant

    Science.gov (United States)

    Klapstova, A.; Horakova, J.; Shynkarenko, A.; Lukas, D.

    2017-10-01

    Glaucoma is a frequent reason of loss vision. It is usually caused by increased intraocular pressure leading to damage of optic nerve head. This work deals with the development of fibrous structure suitable for glaucoma drainage implants (GDI). Commercially produced metallic glaucoma implants are very effective in lowering intraocular pressure. However, these implants may cause adverse events such as damage to adjacent tissue, fibrosis, hypotony or many others [1]. The aim of this study is to reduce undesirable properties of currently produced drains and improve their properties by creating of the composite fibrous drain for achieve a normal intraocular pressure. Two types of electrospinning technologies were used for the production of very small tubular implants. First type was focused for production of outer part of tubular drain and the second type of electrospinning method made the inner part of shape follows the connections of both parts. Complete implant had a special properties suitable for drainage of fluid. Morphological parameters, liquid transport tests and in-vitro cell adhesion tests were detected.

  7. Translucent Insulation

    DEFF Research Database (Denmark)

    Rahbek, Jens Eg

    1998-01-01

    Two new types of translucent materials are presented. One is translucent fiber insulation and the other type is a new type of hony-comb made of Celulose-acetat. Data for the materials and calculations of energy savings when using the materials in building envelopes are presented....

  8. Better and cheaper extra insulation

    DEFF Research Database (Denmark)

    Rudbeck, Claus Christian

    1998-01-01

    of buildings. The thermal performance of the systems is compared to an ideal situation, showing that there is still a potential of further savings by improving the design of the insulation systems.To improve the thermal performance of the systems a number of product developments are proposed.......In the current energy plan, focus in placed on further savings of heat in buildings. If the target of the energy plan should be achieved, there is a need for saving heat both in new and existing buildings.The article investigate and compare the properties of several systems for external insulation...

  9. Energy conservation by thermal insulation and refurbishment of the heating system in housing estate `Sudeckie` in Swiebodzice. Final monitoring report 1996 - 97 and 1997 - 98, Poland

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    The site for the project is located in South West Poland in the city of Swiebodzice, in a housing society called `Sudeckie`. The society is served by its own district heating network supplied from a coal fired boiler plant. There are plans for a future conversion of the boiler plant to natural gas, but as yet there is no gas pipeline in the district to supply the plant. The monitoring programme is based on the readings from energy meters installed in all buildings, in the boiler house and from data obtained from a number of thermologgers placed in selected apartments. The manual readings are done by the local staff in the housing society and the boiler house. In the 800 flats housing estate the energy saving activities are already showing good results by a clear and detectable drop in the energy consumption. The total energy savings due to thermal insulation, thermostatic valves and balancing valves in 1996-97 are approximately 15% and in 1997-98 the savings have increased to 30%. The effect from the installed thermostatic valves is improved comfort through better control of indoor temperature, as well as energy savings by reducing the excess heat. The boiler house has been furnished with variable speed pumps and frequency converters and automatic weather compensating equipment. The boiler house has also been equipped with a pressure holding system and control valves for heat control. In the houses thermostatic valves have been mounted at the radiators, and air venting equipment has been installed at the top of the risers. (EG)

  10. Evaluation of stability of allergen extracts for sublingual immunotherapy during transport under unfavourable temperature conditions with an innovative thermal insulating packaging.

    Science.gov (United States)

    Puccinelli, P; Natoli, V; Dell'albani, I; Scurati, S; Incorvaia, C; Barbieri, S; Masieri, S; Frati, F

    2013-10-01

    Many pharmaceutical and biotechnological products are temperature-sensitive and should normally be kept at a controlled temperature, particularly during transport, in order to prevent the loss of their stability and activity. Therefore, stability studies should be performed for temperature-sensitive products, considering product characteristics, typical environmental conditions, and anticipating environmental extremes that may occur during product transport in a specific country. Staloral products for sublingual immunotherapy are temperature sensitive and are labelled for maintenance under refrigerated conditions (2-8°C). Given the peculiar climatic context of Italy and the great temperature fluctuations that may occur during transport, this study was aimed at evaluating the impact of a new engineered thermal insulating packaging for Staloral. In particular, the purpose was to assess whether the new packaging could create a container condition able to preserve the stability and immunological activity of the product during the transport phase throughout Italy. The results showed that the range of temperatures that can affect the product, in the area surrounding the product packaging, may reach a peak of 63°C during transport under the most unfavourable climatic conditions, i.e. in a non-refrigerated van during the summer season, from the site of production in France to the patient's house in Catania, the city with the highest temperatures in Italy. However, the highest temperature reached inside the vaccine did not exceed 45°C over a period of about 2 h. The ELISA inhibition test on samples subjected to the extreme temperature conditions previously defined (45°C) showed an immunological activity higher than 75% of that initially measured and was comparable to those obtained with samples stored at controlled temperature (5°C). This means that, even in the worst case scenario, the structure of the allergen extracts is not influenced and the vaccine potency is

  11. Green insulation: hemp fibers

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2011-09-15

    Indian hemp (Cannabis indica) is known for its psychotropic values and it is banned in most countries. However, industrial hemp (Cannabis sativa) is known for its tough fibers. Several manufactures in Europe including, small niche players, have been marketing hemp insulation products for several years. Hemp is a low environmental impact material. Neither herbicide nor pesticide is used during the growth of hemp. The fibers are extracted in a waste-free and chemical-free mechanical process. Hemp can consume CO2 during its growth. In addition, hemp fiber can be disposed of harmlessly by composting or incineration at the end of its life. Hemp fibers are processed and treated only minimally to resist rot and fungal activity. There is little health risk when producing and installing the insulation, thanks to the absence of toxic additive. Its thermal resistance is comparable to mineral wool. But the development and marketing of hemp fibers may be restricted in North America.

  12. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken

    2004-01-01

    form the weakest part of the thermal envelope with respect to heat loss coefficient, but on the other hand also play an important role for passive solar energy utilisation. For window orientations other than south, the net energy balance will be close to or below zero. However, the properties......Monolithic silica aerogel offers the possibility of combining super insulation and high solar energy transmittance, which has been the background for a previous and a current EU project on research and development of monolithic silica aerogel as transparent insulation in windows. Generally, windows...... of aerogel glazing will allow for a positive net energy gain even for north facing vertical windows in a Danish climate during the heating season. This means that high quality daylight can be obtained even with additional energy gain. On behalf of the partners of the two EU projects, results related...

  13. Development of High Performance Composite Foam Insulation with Vacuum Insulation Cores

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Kaushik [ORNL; Desjarlais, Andre Omer [ORNL; SmithPhD, Douglas [NanoPore, Inc.; LettsPhD, John [Firestone Building Products; YaoPhD, Jennifer [Firestone Building Products

    2016-01-01

    Development of a high performance thermal insulation (thermal resistance or R-value per inch of R-12 hr-ft2- F/Btu-in or greater), with twice the thermal resistance of state-of-the-art commercial insulation materials ( R6/inch for foam insulation), promises a transformational impact in the area of building insulation. In 2010, in the US, the building envelope-related primary energy consumption was 15.6 quads, of which 5.75 quads were due to opaque wall and roof sections; the total US consumption (building, industrial and transportation) was 98 quads. In other words, the wall and roof contribution was almost 6% of the entire US primary energy consumption. Building energy modeling analyses have shown that adding insulation to increase the R-value of the external walls of residential buildings by R10-20 (hr-ft2- F/Btu) can yield savings of 38-50% in wall-generated heating and cooling loads. Adding R20 will require substantial thicknesses of current commercial insulation materials, often requiring significant (and sometimes cost-prohibitive) alterations to existing buildings. This article describes the development of a next-generation composite insulation with a target thermal resistance of R25 for a 2 inch thick board (R12/inch or higher). The composite insulation will contain vacuum insulation cores, which are nominally R35-40/inch, encapsulated in polyisocyanurate foam. A recently-developed variant of vacuum insulation, called modified atmosphere insulation (MAI), was used in this research. Some background information on the thermal performance and distinguishing features of MAI has been provided. Technical details of the composite insulation development and manufacturing as well as laboratory evaluation of prototype insulation boards are presented.

  14. Paget's disease and fibrous dysplasia.

    Science.gov (United States)

    Hullar, Timothy E; Lustig, Lawrence R

    2003-08-01

    Paget's disease and fibrous dysplasia are benign disorders that can involve the temporal bone and skull base. They commonly lead to otolaryngologic symptoms such as impingement of cranial nerves or the orbit or blockage of the external auditory canal or paranasal sinuses, although they can often be a challenge to diagnose because of their insidious presentation. Their benign nature and common presentation within the difficult-to-access confines of the skull base should lead the clinician to exercise caution in their treatment, reserving surgical intervention for either diagnosis or the relief of symptoms. As a better understanding of the etiology of these conditions develops and new pharmacotherapeutic agents are tested, it is likely that physicians will be able to turn to medical rather than surgical techniques to treat these disorders.

  15. Posttraumatic Cranial Cystic Fibrous Dysplasia

    Directory of Open Access Journals (Sweden)

    Arata Tomiyama

    2011-01-01

    Full Text Available A 14-year-old was girl admitted to our hospital with a subcutaneous mass of the occipital head. The mass had grown for 6 years, after she had sustained a head injury at the age of 6, and was located directly under a previous wound. Skull X-ray Photograph (xp, computed tomography (CT, and magnetic resonance imaging (MRI showed a bony defect and cystic changes in the skull corresponding to a subcutaneous mass. Bone scintigraphy revealed partial accumulation. The patient underwent total removal of the skull mass, and the diagnosis from the pathological findings of the cyst wall was fibrous dysplasia (FD. The radiographic findings for cystic cranial FD can be various. Progressive skull disease has been reported to be associated with head trauma, but the relationship between cranial FD and head trauma has not been previously reported. Previous studies have suggested that c-fos gene expression is a key mechanism in injury-induced FD.

  16. Nutritional fibrous osteodystrophy in goats

    Directory of Open Access Journals (Sweden)

    Paulo M Bandarra

    2011-10-01

    Full Text Available Seven out of 25 goats from a southern Brazilian flock developed nutritional fibrous osteodystrophy. Affected animals were younger than 1 year of age and were confined in stalls and fed a concentrate ration containing 1:6 calcium:phosphorus ratio. The remaining flock (35 goats was managed at pasture and showed no disease. Clinical signs were characterized by mandibular and maxillary enlargements, varying degrees of mouth opening and protruding tongue, dyspnea, apart of abnormalities of prehension and mastication. Affected animals had increased seric levels of phosphorus and parathormone, as well as higher alkaline phosphatase activity. Postmortem examination on three succumbed goats revealed bilateral enlargement of the maxilla and mandibula, and loose teeth, apart of multiple incomplete rib fractures in one of them. Severe diffuse proliferation of loose connective tissue surrounded the osteoid trabeculae, many of which were partially or completely non-mineralized. Mineralized osteoid trabeculae showed osteoclasts in the Howship's lacunae.

  17. Creep of fibrous composite materials

    DEFF Research Database (Denmark)

    Lilholt, Hans

    1985-01-01

    Models are presented for the creep behaviour of fibrous composite materials with aligned fibres. The models comprise both cases where the fibres remain rigid in a creeping matrix and cases where the fibres are creeping in a creeping matrix. The treatment allows for several contributions...... to the creep strength of composites. The advantage of combined analyses of several data sets is emphasized and illustrated for some experimental data. The analyses show that it is possible to derive creep equations for the (in situ) properties of the fibres. The experiments treated include model systems...... such as Ni + W-fibres, high temperature materials such as Ni + Ni3Al + Cr3C2-fibres, and medium temperature materials such as Al + SiC-fibres. For the first two systems reasonable consistency is found for the models and the experiments, while for the third system too many unquantified parameters exist...

  18. Investigation of sound and thermal insulation of pilot projects for low cost housing and exemplary solutions for weak points in building physics. Untersuchung des Schall- und Waermeschutzes in Pilotprojekten fuer den kostenguenstigen Wohnungsbau und beispielhafte Loesungen fuer bauphysikalische Schwachstellen

    Energy Technology Data Exchange (ETDEWEB)

    Lott, G.; Kurz, R.; Jenisch, R.; Lutz, P.

    1990-03-05

    In the framework of the research program six different pilot projects for housing at lowest cost have been investigated shortly before the occupation of the dwellings with regard to the quality of sound and thermal insulation. When correctly executed the attained sound insulation level met the minimum requirements of DIN 4109-62 and was thus slightly below average of other buildings. Composite screed with impact sound absorbent flooring, sound bridges in floating floors, very light interior walls, single-leaf partition wall in terraced houses, site concrete double walls, brickwork double walls with thinner leafs and wider joints, lengthwise sound conduction for attic storeys as well as stairs, doors and balconies have been investigated. Thermal insulation of exterior building units easily fulfilled the requirements of the DIN 4108. It is recommended to further develop at low cost light interior work with prefabricated walls as this method of construction is with regard to lengthwise sound conduction and installation noises not nearly as problematic as light interior walls. (BWI) With 29 figs., 2 annexes.

  19. 49 CFR 179.201-11 - Insulation.

    Science.gov (United States)

    2010-10-01

    ...) Insulation shall be of sufficient thickness so that the thermal conductance at 60 °F. is not more than 0.075... 49 Transportation 2 2010-10-01 2010-10-01 false Insulation. 179.201-11 Section 179.201-11 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY...

  20. External insulation with cellular plastic materials

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt; Nielsen, Anker

    2014-01-01

    External thermal insulation composite systems (ETICS) can be used as extra insulation of existing buildings. The system can be made of cellular plastic materials or mineral wool. There is a European Technical guideline, ETAG 004, that describe the tests that shall be conducted on such systems...

  1. Propiedades térmicas e hídricas de materiales aislantes apropiadas para fábricas históricas = Thermal and hygric properties of insulation materials suitable for historic fabrics

    Directory of Open Access Journals (Sweden)

    Rosanne Walker

    2016-08-01

    Full Text Available Mejorar el rendimiento térmico de los edificios mediante la adaptación del aislamiento puede reducir la pérdida innecesaria de calor y energía minimizando el impacto ambiental. El aislamiento térmico interior es a menudo el elegido en los edificios históricos para preservar sus características. Sin embargo, el aislamiento interior puede aumentar la acumulación de humedad en paredes que socavan su durabilidad. Hay una falta de conocimiento sobre la eficacia de sólidos muros históricos y el impacto del aislamiento interno en su comportamiento higrotérmico. Este artículo investiga las propiedades térmicas e hídricas de siete opciones de aislamiento internos, incluyendo la pintura térmica, aerogel (AG, corcho-cal (CL, cal-cáñamo (HL, silicato de calcio bordo (CSB, tablero de fibra de madera (TFB y placa de polisocianurato (PIR. Sus propiedades se comparan con un enlucido de cal tradicional. El PIR y el aerogel AG muestran extraordinarias propiedades térmicas que contribuyen a la comodidad y ahorro de energía, y la CL y HL son permeables al vapor y a la capilaridad. Estos tienen aproximadamente el doble de la masa térmica de los otros aislantes. Además, la CL tiene una buena inercia térmica (segunda difusividad más baja y, a pesar de su contenido orgánico, una adsorción de baja a alta RH. Abstract Improving the thermal performance of buildings by retrofitting insulation can reduce unnecessary heat loss and building operational energy minimising environmental impact. Internal thermal insulation is often favoured for historic buildings to preserve their features. However, internal insulation may increase moisture accumulation in walls undermining their durability. There is a lack of knowledge on the performance of historic solid walls and the impact of internal insulation in their hygrothermal behaviour. This paper investigates the thermal and hygric properties of seven internal insulation options including thermal paint

  2. Economical evaluation of damaged vacuum insulation panels in buildings

    Science.gov (United States)

    Kim, Y. M.; Lee, H. Y.; Choi, G. S.; Kang, J. S.

    2015-12-01

    In Korea, thermal insulation standard of buildings have been tightened annually to satisfy the passive house standard from the year 2009. The current domestic policies about disseminating green buildings are progressively conducted. All buildings should be the zero energy building in the year 2025, obligatorily. The method is applied to one of the key technologies for high-performance insulation for zero energy building. The vacuum insulation panel is an excellent high performance insulation. But thermal performance of damaged vacuum insulation panels is reduced significantly. In this paper, the thermal performance of damaged vacuum insulation panels was compared and analyzed. The measurement result of thermal performance depends on the core material type. The insulation of building envelope is usually selected by economic feasibility. To evaluate the economic feasibility of VIPs, the operation cost was analyzed by simulation according to the types and damaged ratio of VIPs

  3. Compact vacuum insulation

    Science.gov (United States)

    Benson, D.K.; Potter, T.F.

    1992-10-27

    Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases there between are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths. Glass or porcelain-enameled liners in combination with the glass spacers and metal sidewalls effectively decrease thermal conductivity, and various laminates, including wood, porcelain-enameled metal, and others effectively increase the strength and insulation capabilities of the panels. Also, a metal web is provided to hold the spacers in place, and strategic grooves are shown to accommodate expansion and contraction or shaping of the panels. 35 figs.

  4. A Novel Method to Decrease Micro-residual Stresses of Fibrous Composites by Adding Carbon Nanotube

    Directory of Open Access Journals (Sweden)

    M. M. Shokrieh

    2013-12-01

    Full Text Available In this research, a novel method to decrease micro-residual stresses of fibrous composites by adding carbon nanotubes (CNTs is proposed in detail. The negative coefficient of thermal expansion and the high young’s modulus of CNTs can be utilized to counterbalance the process induced residual stresses in composites. To this end, first, the effects of adding CNTs to the matrix of fibrous composites in reducing the coefficient of thermal expansion (CTE and increasing of young’s modulus of matrix are studied theoretically. Then, a three phase micromechanical model (the energy method is used to model the effect of CNT in reducing the residual stresses of fibrous composites. The results show that by addition of CNTs, enhancements in properties of matrix are obtained and lead to decrease in micro-residual stresses of matrix and fiber up to 72%.

  5. Aerogel Insulation to Support Cryogenic Technologies, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is seeking a high performance thermal insulation material for cryogenic applications in space launch development. Many of the components in cryogenic...

  6. Cryogenic Insulation Standard Data and Methodologies

    Data.gov (United States)

    National Aeronautics and Space Administration — Extending some recent developments in the area of technical consensus standards for cryogenic thermal insulation systems, a preliminary Inter-Laboratory Study of...

  7. Systems and Methods for Providing Insulation

    Science.gov (United States)

    Golden, Johnny L. (Inventor)

    2015-01-01

    Systems and methods provide a multi-layer insulation (MLI) that includes a plurality of sealed metalized volumes in a stacked arrangement, wherein the plurality of sealed metalized volumes encapsulate a gas therein, with the gas having one of a thermal insulating property, an acoustic insulating property, or a combination insulating property thereof. The MLI also includes at least one spacer between adjacent sealed metalized volumes of the plurality of sealed metalized volumes and a protective cover surrounding the plurality of sealed metalized volumes.

  8. Towards low energy building using vacuum insulation panels. Advantages and disadvantages

    Directory of Open Access Journals (Sweden)

    Adrian-Alexandru CIOBANU

    2013-12-01

    Full Text Available The increasing interest in building developments with very low energy consumption, energy-positive or passive houses has directed the attention of those involved in this area to high thermal performance insulation materials, like vacuum insulation panels (VIP. Vacuum insulation panels are part of high thermal performance insulations, which attempts to be introduced and used in the construction field. The main interest for these materials is due to their thermal properties, namely to their very low thermal conductivity (of 5 to 8 times compared with traditional thermal insulation materials (mineral wool, extruded/expanded polystyrene. The thermal conductivity of thermal insulation widely used, hence traditional or classical insulation names, as expanded polystyrene (EPS, extruded polystyrene (XPS, mineral wool or polyurethane foam (PUR has typical values between 0.03 and 0.05 W/(mK. Using these types of insulations to fulfill performance envelope elements in terms of energy, leads to the adoption of an increased insulation thickness. Vacuum insulation panels may offer new solution for high performance insulation with a thickness in order of a few centimeters compared to the conventional insulation. Vacuum insulation panels can be used as independently insulation, replacing entirely the conventional ones or as additional insulation.

  9. Solitary Fibrous Tumor of the Uterus

    Directory of Open Access Journals (Sweden)

    Po-Wei Chu

    2006-12-01

    Conclusion: The behavior of solitary fibrous tumors arising from the uterus is difficult to evaluate; therefore, complete surgical excision featuring clear margins and comprehensive follow-up is recommended.

  10. Evaluation and histological maturation characteristics of fibrous ...

    African Journals Online (AJOL)

    osseous lesions (FOLS) that are generally considered to be separate entities distinguishable by histologic and radiographic features. The histological maturation of these lesions involves an initial fibrous state, an intermediate mixed and a final ...

  11. Isolated fibrous dysplasia of the sphenoid sinus.

    Science.gov (United States)

    Buyuklu, Fuat; Tarhan, Erkan; Cakmak, Ozcan; Ozgirgin, Nuri; Arikan, Unser

    2005-12-01

    Fibrous dysplasia is an uncommon benign bone disorder of unknown etiology in which normal medullary bone is replaced by fibrotic and osseous tissue. Solitary involvement of the sphenoid sinus is unusual. Here, we present the case of a 28-year-old man complaining of occipital and vertical headache. Imaging modalities demonstrated an expansile lesion filling the entire sphenoid sinus. Biopsy specimen was obtained by endoscopic sphenoidotomy. Diagnosis of fibrous dysplasia was made by imaging results and pathologic examination.

  12. Aggressive fibrous dysplasia of the maxillary sinus

    Energy Technology Data Exchange (ETDEWEB)

    Shapeero, L.G. (Dept. of Radiology, Inst. Gustave-Roussy, Villejuif (France) Dept. of Radiology, California Univ., San Francisco, CA (United States)); Vanel, D. (Dept. of Radiology, Inst. Gustave-Roussy, Villejuif (France)); Ackerman, L.V. (Dept. of Pathology, State Univ. of New York, Stony Brook, NY (United States)); Terrier-Lacombe, M.J. (Dept. of Radiology, Inst. Gustave-Roussy, Villejuif (France)); Housin, D. (Dept. of Radiology, Inst. Gustave-Roussy, Villejuif (France)); Schwaab, G. (Dept. of Ear, Nose, and Throat, Inst. Gustave-Roussy, Villejuif (France)); Sigal, R. (Dept. of Radiology, Inst. Gustave-Roussy, Villejuif (France)); Masselot, J. (Dept. of Radiology, Inst. Gustave-Roussy, Villejuif (France))

    1993-11-01

    Five of 34 patients (ages 4-21 years), who were subsequently diagnosed histologically as having fibrous dysplasia of the maxillary sinus, rapidly developed soft tissue masses of the malar region over a period of less than 4 months with accompanying pain (2 patients) and nasal obstruction and exophthalmos (2 patients). Each was clinically suspected of having a sarcoma. After resection, all lesions developed regrowth. At histopathologic examination, both initial and recurrent masses proved to be typical fibrous dysplasia. (orig./UWA)

  13. Isolated fibrous dysplasia of the ethmoid sinus

    OpenAIRE

    Yenigun, Alper; Akyuz, Servet

    2015-01-01

    Fibrous dysplasia is a benign fibro-osseous lesion progressing with one or more bone involvements in the skeleton. Even though it is a benign tumor, it may potentially transform into a malignant one. While the most frequently involved zones in the head–neck zone include the maxilla, mandible, parietal, occipital, and temporal zones, the involvement of the ethmoid bone is rather rare. This article presents the case of a female patient who was diagnosed with fibrous dysplasia in the right ethmo...

  14. Aggressive fibrous dysplasia of the maxillary sinus

    International Nuclear Information System (INIS)

    Shapeero, L.G.; Vanel, D.; Ackerman, L.V.; Terrier-Lacombe, M.J.; Housin, D.; Schwaab, G.; Sigal, R.; Masselot, J.

    1993-01-01

    Five of 34 patients (ages 4-21 years), who were subsequently diagnosed histologically as having fibrous dysplasia of the maxillary sinus, rapidly developed soft tissue masses of the malar region over a period of less than 4 months with accompanying pain (2 patients) and nasal obstruction and exophthalmos (2 patients). Each was clinically suspected of having a sarcoma. After resection, all lesions developed regrowth. At histopathologic examination, both initial and recurrent masses proved to be typical fibrous dysplasia. (orig./UWA)

  15. Modelling and analysing oriented fibrous structures

    International Nuclear Information System (INIS)

    Rantala, M; Lassas, M; Siltanen, S; Sampo, J; Takalo, J; Timonen, J

    2014-01-01

    A mathematical model for fibrous structures using a direction dependent scaling law is presented. The orientation of fibrous nets (e.g. paper) is analysed with a method based on the curvelet transform. The curvelet-based orientation analysis has been tested successfully on real data from paper samples: the major directions of fibrefibre orientation can apparently be recovered. Similar results are achieved in tests on data simulated by the new model, allowing a comparison with ground truth

  16. Energy saving by means of air conditioning equipment replacement and the household application of thermal insulation; Ahorro de energia electrica por reemplazo de equipos de aire acondicionado y aplicacion de aislamiento termico en viviendas

    Energy Technology Data Exchange (ETDEWEB)

    Peralta Solorio, Jose Luis [Fideicomiso para el Ahorro de la Energia (Mexico)

    2005-07-15

    An extension study of the Financing Program for Energy Saving looked for the evaluation of the electric energy saving potential obtained by the replacement of air conditioning equipment and the application of thermal insulation in 30 houses of two Mexican cities with warmth climate. In a joint effort with Comision Federal de Electricidad the consumption files of the users were analyzed and field measurements of electric demand and of refrigeration were made. As a following step the change of the refrigeration necessities derived from the application of thermal insulation were evaluated as well as the energy efficiency improvement obtained by the substitution of the air conditioning equipment and the favorable results obtained by the implementation of both measures - thermal insulation and change of air conditioning equipment in a joint form. This way, as a conclusion, the optimum sequence of application of these measures is revealed. [Spanish] Un estudio extension del Programa de Financiamiento para el Ahorro de Energia Electrica busco evaluar el potencial de ahorro de energia electrica alcanzado por el reemplazo de equipos de aire acondicionado y la aplicacion de aislamiento termico en 30 viviendas de dos ciudades mexicanas con clima calido. En un esfuerzo conjunto con la Comision Federal de Electricidad se analizaron los historiales de consumo de los usuarios y se efectuaron las mediciones de campo de demanda electrica y de refrigeracion. Como paso siguiente se valoro el cambio en las necesidades de refrigeracion derivado de la aplicacion de aislamiento termico al igual que la mejora en eficiencia energetica obtenida por la sustitucion de aire acondicionado y se identificaron los resultados favorecedores arrojados por la implementacion de ambas medidas -aislamiento termico y cambio de equipo de aire acondicionado- en forma conjunta. De esta manera, como conclusion, se devela la mas optima secuencia de aplicacion de estas medidas.

  17. Fibrous incudostapedial joint in congenital aural atresia.

    Science.gov (United States)

    Balaker, Ashley E; Roberson, Joseph B; Goldsztein, Hernan

    2014-04-01

    (1) Determine the prevalence of a non-bony or fibrous incudostapedial (IS) joint in the setting of congenital aural atresia. (2) Assess this anomaly's impact on surgical management and associated hearing outcomes. Retrospective chart review. Subspecialty private practice. Operative reports and audiometric data of patients who underwent congenital aural atresia repair by a single surgeon from 2007 to 2011 were reviewed for operative anatomic findings and audiometric outcomes. Two hundred twenty-eight operations on 206 ears were performed. Median age was 5 years old. Fifty-five (26.7%) of these ears had a fibrous IS joint. The severity of this anomaly was graded as mild in 23 ears, moderate in 20 ears, and severe in 12 ears. Mean postoperative pure tone air conduction (PTA2) in the severely fibrous group was 51 compared to 46 in the moderate group (P = .03) and 41 in the mild group (P = .006). Patients with a fibrous IS joint who underwent successful ossicular chain reconstruction (OCR) had a mean postoperative PTA2 of 30, which was a significantly better outcome than in patients with moderately or severely fibrous IS joints who did not have OCR (P atresia. The severity of this anomaly has important implications for postoperative hearing results. These findings suggest that ossicular chain reconstruction should be performed in moderately or severely fibrous cases.

  18. Implanted Si atoms shifting between Ga sites and As sites by thermal stress in conductive-layer GaAs crystals on semi-insulating substrates

    Science.gov (United States)

    Saito, Yasuyuki

    1992-04-01

    Large (0.8 V order) discrepancies of threshold voltage Vth between the predicted Vth values by the Lindhard-Scharff-Schio/tt Gaussian approximate calculation and the Vth of the tungsten nitride (WNx) self-alignment (SA) gate GaAs metal-semiconductor field-effect transistors (MESFETs) were observed. These discrepancies were confirmed by the comparison of the Vth of the WNx-SA-gate MESFETs and the Vth of the (N+: high carrier concentration layers self-aligned of source-drain electrodes)-less conventional MESFETs on 2-in.-diam semi-insulating substrates from liquid-encapsulated-Czochralski-technique-grown boules. The discrepancy was also analyzed by the capacitance-voltage (C-V) measurement of large-diameter (440 μm) Schottky diodes which were built into the MESFET arrays. It was found that for obtained SA-process carrier depth profiles (Si, 150 keV, 3×1012 cm-2) the carrier concentration at a depth of 0.25 μm decreased from 5.3×1016 to 2.0×1016 cm-3, but, on the other hand, the peak carrier concentration slightly decreased from 12.8×1016 to 12.4×1016 cm-3. By the calculation for Vth on the basis of the actual C-V carrier depth profiles, it was found that the carrier concentration decrease was comparable to the Vth variation (0.8 V). Furthermore, the Vth variation of the shallow channel implantation (50 keV) was comparable to that of the deep channel implantation (150 keV). As a result of the experiment and analysis, it was found that the large Vth variation for the SA N+ process was caused by reoccupation (Ga sites to As sites) of implanted Si atoms in the channel active-layer crystal by tensile stress formed by the thermal-expansion coefficient difference between chemical-vapor deposition (CVD) phosphosilicate glass (or CVD SiO2) film and (100) GaAs substrate crystal. The Si atom reoccupation quantity was, for the first time, explained by the Si atom compensation ratio equation as a function of the bond length (Si-As and Si-Ga) variation, an equation which

  19. Field evaluation of reflective insulation in south east Asia

    Science.gov (United States)

    Teh, Khar San; Yarbrough, David W.; Lim, Chin Haw; Salleh, Elias

    2017-12-01

    The objective of this research was to obtain thermal performance data for reflective insulations in a South East Asia environment. Thermal resistance data (RSI, m2 ṡ K/W) for reflective insulations are well established from 1-D steady-state tests, but thermal data for reflective insulation in structures like those found in South East Asia are scarce. Data for reflective insulations in South East Asia will add to the worldwide database for this type of energy-conserving material. RSI were obtained from heat flux and temperature data of three identical structures in the same location. One unit did not have insulation above the ceiling, while the second and third units were insulated with reflective insulation with emittance less than 0.05. RSI for the uninsulated test unit varied from 0.37 to 0.40 m2 ṡ K/W. RSI for a single-sheet reflective insulation (woven foil) varied from 2.15 to 2.26 m2 ṡ K/W, while bubble-foil insulation varied from 2.69 to 3.09 m2 ṡ K/W. The range of RSI values resulted from differences in the spacing between the reflective insulation and the roof. In addition, the reflective insulation below the roof lowered attic temperatures by as much as 9.7° C. Reductions in ceiling heat flux of 80 to 90% relative to the uninsulated structure, due to the reflective insulation, were observed.

  20. Calculation of clothing insulation by serial and parallel methods : effects on clothing choice by IREQ and thermal responses in the cold

    NARCIS (Netherlands)

    Kuklane, K.; Gao, C.; Holmér, I.; Giedraityte, L.; Bröde, P.; Candas, V.; Hartog, E.A. den; Meinander, H.; Richards, M.; Havenith, G.

    2007-01-01

    Cold protective clothing was studied in 2 European Union projects. The objectives were (a) to examine different insulation calculation methods as measured on a manikin (serial or parallel), for the prediction of cold stress (IREQ); (b) to consider the effects of cold protective clothing on metabolic

  1. Electrohydrodynamic Direct-Write Orderly Micro/Nanofibrous Structure on Flexible Insulating Substrate

    Directory of Open Access Journals (Sweden)

    Jiang-Yi Zheng

    2014-01-01

    Full Text Available AC pulse-modulated electrohydrodynamic direct-writing (EDW was utilized to direct-write orderly micro/nanofibrous structure on the flexible insulating polyethylene terephthalate (PET substrate. During the EDW process, AC electrical field induced charges to reciprocate along the jet and decreased the charge repulsive force that applied on charged jet. Thanks to the smaller charge repulsive force, stable straight jet can be built up to direct-write orderly micro/nanofibrous structures on the insulating substrate. The minimum motion velocity required to direct-write straight line fibrous structure on insulating PET substrate was 700 mm/s. Moreover, the influences of AC voltage amplitude, frequency, and duty cycle ratio on the line width of fibrous structures were investigated. This work proposes a novel solution to overcome the inherent charge repulsion emerging on the insulating substrate, and promotes the application of EDW technology on the flexible electronics.

  2. Pseudotumoral fibrous dysplasia of the maxilla

    International Nuclear Information System (INIS)

    Vanel, D.; Couanet, D.; Piekarski, J.D.; Masselot, J.; Micheau, C.; Schwaab, G.

    1980-01-01

    Clinical, radiological, and histological problems arise relating to fibrous dysplasia of the maxilla. Clinically, 11 of our 39 cases developed so rapidly that the lesions were suspected of being malignant. The histological diagnosis may be very difficult, since any tumoural, reactive, or healing process may simulate fibrous dysplasia. As a general rule, the diagnosis is established most easily by the radiological examination. The radiologist's responsibility is important, as mistakes may have serious consequences. We report four pseudotumoural forms of maxillary sinus fibrous dysplasia. All were characterised clinically by rapid evolution, radiologically by opacity of the sinus with apparent destruction of its wall, and histologically by difficulty in establishing the diagnosis. In two cases indeed, the initial histological interpretation was an osteogenic sarcoma. Due to its excellent densitometric resolution, computed tomography provides an invaluable contribution by displaying the fibrous wall of an intact or even thickened maxillary sinus when conventional radiology has suggested a destructive process. In difficult cases of maxillary fibrous dysplasia, computed tomography should be used as a supplementary investigation to establish the correct diagnosis. (orig.) [de

  3. Simple test for physical stability of cryogenic tank insulation

    Science.gov (United States)

    Rossello, D.

    1968-01-01

    Qualitative test determines the ability of insulation liners used on liquid hydrogen tanks to withstand stresses produced by the thermal shocks imparted to the insulation during tank filling and drainage. Test specimens are bonded to metal plates with a low thermal expansion coefficient and are immersed in liquid hydrogen.

  4. Moisture dependent thermal properties of hydrophilic mineral wool: application of the effective media theory

    Directory of Open Access Journals (Sweden)

    Iñigo Antepara

    2015-09-01

    calculation of solid matrix thermal conductivity. Subsequently, the thermal conductivity dependence on moisture content is evaluated by means of several mixing formulas. To verify the obtained results, Wiener’s and Hashin-Shtrikman’s bounds are used. The results show that the application of homogenization techniques can provide useful estimates of measured data and can be successfully used for much less time consuming thermal conductivity evaluation even for the highly inhomogeneous fibrous material such as mineral wool. The data on thermal properties can find use in building practice, especially in the design of thermal insulation building envelopes.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7334

  5. Congenital fibrous hamartoma of the knee

    International Nuclear Information System (INIS)

    Arioni, Cesare; Bellini, Carlo; Risso, Francesco Maria; Scopesi, Fabio; Serra, Giovanni; Oddone, Mauro; Toma, Paolo; Nozza, Paolo

    2006-01-01

    A full-term male infant presented at birth with a hard swelling of the left knee. The lemon-sized lesion was fixed to the underlying knee muscles, while the overlying skin was stretched and shiny; there was no bruit. Radiography, sonography and MRI suggested a soft-tissue tumour. After surgical excision, histology showed the presence of fibrous and mesenchymal tissue, with mature adipose tissue. Fibrous hamartoma of infancy was diagnosed. Among soft-tissue tumours, fibrous hamartoma of infancy is a rare and benign lesion, occurring in the first 2 years of life. The tumour mainly affects the trunk, axilla, and upper extremities. This infant had unique involvement of the knee. The treatment of choice is local excision. (orig.)

  6. CT Imaging of Craniofacial Fibrous Dysplasia

    Directory of Open Access Journals (Sweden)

    Zerrin Unal Erzurumlu

    2015-01-01

    Full Text Available Fibrous dysplasia is a benign fibroosseous bone dysplasia that can involve single (monostotic or multiple (polyostotic bones. Monostotic form is more frequent in the jaws. It is termed as craniofacial fibrous dysplasia, when it involves, though rarely, adjacent craniofacial bones. A 16-year-old girl consulted for a painless swelling in the right posterior mandible for two years. Panoramic radiography revealed ground-glass ill-defined lesions in the three different regions of the maxilla and mandible. Axial CT scan (bone window showed multiple lesions involving skull base and facial bones. Despite lesions in the skull base, the patient had no abnormal neurological findings. The lesion was diagnosed as fibrous dysplasia based on radiological and histopathological examination. In this paper, CT findings and differential diagnosis of CFD are discussed. CT is a useful imaging technique for CFD cases.

  7. An experimental investigation on morphological, mechanical and thermal properties of date palm particles reinforced polyurethane composites as new ecological insulating materials in building

    OpenAIRE

    A. Oushabi; S. Sair; Y. Abboud; O. Tanane; A. El Bouari

    2017-01-01

    The rigid polyurethane (PU) with apparent density about 40 kg/m3 was prepared using commercial polyols and polyisocyanate. This reference petrochemical formulation was modified with natural and renewable components such as date palm particles (DPP). The goal of this investigation was to reduce the environmental impacts, and reduce the cost of the petroleum based polyurethane (PU) by obtaining polyurethane/date palm particles (PU-DPP) composites with the heat insulating and mechanical properti...

  8. Effect of façade impregnation on feasibility of capillary active thermal internal insulation for a historic dormitory – A hygrothermal simulation study

    DEFF Research Database (Denmark)

    Finken, Gholam Reza; Bjarløv, Søren Peter; Peuhkuri, Ruut Hannele

    2016-01-01

    tested for their hygrothermal performance. The original construction was a 228 mm solid brick masonry wall in a Copenhagen historic dormitory. All simulated systems showed critical relative humidity values above 80% and high risk of mould growth behind the insulation and some also on the interior surface...... masonry walls without additional driving rain protecting especially in case of multi-storey buildings with thin walls in high precipitation areas....

  9. Thermal-oxidative aging of radiation-crosslinked XLPE insulations in the presence of copper conductor: a new test, method and results

    International Nuclear Information System (INIS)

    Kammel, G.; Knoch, G.

    1981-01-01

    In developing radiation-crosslinkable polyolefin-compounds for wire and cable applications one essential aspect -apart from the crosslinkability - is the effective long term stabilization against thermo-oxidative degradation. In this connection problems of interaction with the remaining construction elements of the cables and wires must be considered, above all the reaction with the metallic conductor material, as it is a well known fact that copper -unlike aluminium - has a strong catalytic effect on the thermo-oxidative degradation of polyolefins. A new method of the joint aging of insulation and conductor material is described which offers the possibility not only to determine the thermo-oxidation properties as such, but also to examine the interaction stability, which is important in practice. From the point of view of an effective long term stabilization (service life) of radiation-crosslinked insulations, the customary aging of 7 days at 135 0 C (IEC) is insufficient to provide a good selection. According to the results of the study an aging of 7 or 10 days at 150 0 C should be aimed at for an insulation for 90 0 C (XLPE). This also applies to XLPE in general. (author)

  10. Craniofacial Fibrous Dysplasia of Zygomaticomaxillary Complex.

    Science.gov (United States)

    Nilesh, Kumar; Punde, Prashant; Parkar, M I

    2017-09-01

    Fibrous dysplasia is a benign bone disease first described by Lichtenstein in 1938. It is characterized by progressive replacement of normal bone with fibro-osseous connective tissue. When the disease involves craniofacial skeleton, it results in significant disfigurement and other functional problems. This paper reports a case of large craniofacial fibrous dysplasia involving zygomaticomaxillary complex in a 24-year old male patient. Clinical presentation and imaging characteristics of the pathology is discussed in detail. The disease caused significant facial asymmetry which was satisfactorily managed by surgical recontouring.

  11. Isolated fibrous dysplasia of the ethmoid sinus.

    Science.gov (United States)

    Yenigun, Alper; Akyuz, Servet

    2015-01-01

    Fibrous dysplasia is a benign fibro-osseous lesion progressing with one or more bone involvements in the skeleton. Even though it is a benign tumor, it may potentially transform into a malignant one. While the most frequently involved zones in the head-neck zone include the maxilla, mandible, parietal, occipital, and temporal zones, the involvement of the ethmoid bone is rather rare. This article presents the case of a female patient who was diagnosed with fibrous dysplasia in the right ethmoid sinus based on the paranasal computerized tomography scan that was taken due to the symptoms of pain around the right eye, pressure, and a feeling of being pushed.

  12. A case of intracranial malignant fibrous histiocytoma

    Directory of Open Access Journals (Sweden)

    Amir Hossein Sarrami

    2011-01-01

    Full Text Available We describe a case of intracranial malignant fibrous histiocytoma which had infiltrated pons, cerebellum and basal surface of left temporal lobe without any visible mass. The patient presented with a sudden loss of consciousness and vomiting. Clinical findings, laboratory tests, imaging and examination of the cerebrospinal fluid tended to establish the diagnosis of an infectious condition than a malignancy. Without any response to the antibiotics and with a progressive deterioration of neurologic and mental condition, the patient died after 20 days. In the autopsy, histological and immunohistochemical study of the brain revealed the diagnosis of malignant fibrous histiocytoma (MFH.

  13. Fibrous Protein Structures: Hierarchy, History and Heroes.

    Science.gov (United States)

    Squire, John M; Parry, David A D

    2017-01-01

    During the 1930s and 1940s the technique of X-ray diffraction was applied widely by William Astbury and his colleagues to a number of naturally-occurring fibrous materials. On the basis of the diffraction patterns obtained, he observed that the structure of each of the fibres was dominated by one of a small number of different types of molecular conformation. One group of fibres, known as the k-m-e-f group of proteins (keratin - myosin - epidermin - fibrinogen), gave rise to diffraction characteristics that became known as the α-pattern. Others, such as those from a number of silks, gave rise to a different pattern - the β-pattern, while connective tissues yielded a third unique set of diffraction characteristics. At the time of Astbury's work, the structures of these materials were unknown, though the spacings of the main X-ray reflections gave an idea of the axial repeats and the lateral packing distances. In a breakthrough in the early 1950s, the basic structures of all of these fibrous proteins were determined. It was found that the long protein chains, composed of strings of amino acids, could be folded up in a systematic manner to generate a limited number of structures that were consistent with the X-ray data. The most important of these were known as the α-helix, the β-sheet, and the collagen triple helix. These studies provided information about the basic building blocks of all proteins, both fibrous and globular. They did not, however, provide detailed information about how these molecules packed together in three-dimensions to generate the fibres found in vivo. A number of possible packing arrangements were subsequently deduced from the X-ray diffraction and other data, but it is only in the last few years, through the continued improvements of electron microscopy, that the packing details within some fibrous proteins can now be seen directly. Here we outline briefly some of the milestones in fibrous protein structure determination, the role of the

  14. Energy consumption and the use of thermal insulating materials. A comparative analysis on the tendencies over the time; Consumo de energia y uso de aislamientos termicos - un analisis comparativo de tendencias en el tiempo

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez C, Luis Felipe [Aislantes Minerales, S. A. de C. V. Mexico, D. F. (Mexico)

    1994-12-31

    Through the observations and comparisons conducted on the behavior of change tendencies of population growth, Gross Internal Product and energy consumption, one can analyze if the energy saving tendencies in Mexico are positive and similar to the tendencies in the consumption of thermal insulating materials and similar to other countries figures. The analysis of these figures allows US to detect if the energy saving efforts can be correlated with the consumption of thermal insulating materials and with the standard of living of a country (determined by its per capita income) and establish a future performance index of energy conservation for the adequate utilization o insulating materials of economical thickness. The index proposed in this paper serves this purpose and yields interesting results. Along recent years and as a result of the industrialization level and way of living in Mexico, the energy consumption has increased in a higher rate than the population growth, based on 1980 figures. In this same period, the gross internal product per capita has also increased in a slightly lower rate to the population growth. This means that the figure for Energy Intensity, defined as the rate of energy consumption over the gross internal product, has slightly increased in the same period accounted for, meaning that the country has become more inefficient in recent years. At the same time, the production capacity of thermal insulating materials has remained constant since 1980 until early 1994. This compares unfavorably with all the developed countries, in which the energy intensity has diminished considerably in the last years, while the thermal insulating materials rate has augmented at a rhythm of similar proportions. [Espanol] A base de realizar observaciones y comparaciones del comportamiento de las tendencias de cambio en crecimiento poblacional, Producto Interno Bruto y consumo de energia, se puede analizar si las tendencias de ahorro de energia en Mexico son

  15. The impact of the use of thermal insulating materials in the global climatic change; El impacto del uso de los aislamientos termicos en el cambio de los climas globales

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez C, Luis Felipe [Aislantes Minerales, S.A. de C.V. (Mexico)

    1996-12-31

    One of the technologies for energy saving easier to understand and one of the fastest and economical to install in the dwelling, commercial and industrial, construction is represented by the use of thermal insulation for the thermal energy losses control. As a result of the application of this technology in direct form for the smaller consumption of energy fuels, will have the effect of a lesser emission of pollution gases that produce the green house effect of the earth atmosphere. The thermal insulating materials, made from a variety of raw materials, many of which utilize large amounts of recycled products in the benefit of the smaller use of natural resources, offer annually and permanently reductions in the energy consumption much higher than the energy resources utilized just once in its manufacture. Therefore, they are also an economical way in contributing in the reduction of atmospheric pollutants of the so-called greenhouse gases. [Espanol] Una de las tecnologias para el ahorro de energia mas faciles de comprender y de las mas rapidas y economicas de instalar en la edificacion de vivienda, comercial e industrial, es la que representa el uso de aislamientos termicos para el control de las perdidas de energia termica. Como resultado de la aplicacion de esta tecnologia, en forma directa por el menor consumo de energeticos combustibles, tendra como efecto la menor emision de gases contaminantes que producen el efecto de invernadero en la atmosfera terrestre. Los aislamientos termicos, fabricados de una gran variedad de materiales, muchos de los cuales utilizan grandes cantidades de productos reciclados en beneficio del menor uso de los recursos naturales, ofrecen anualmente y permanentemente reducciones de consumo de energia muy superiores a los recursos energeticos utilizados una sola vez en su manufactura. Por ende, tambien son una forma economica a coadyuvar en la reduccion de contaminantes atmosfericos de los llamados gases de invernadero.

  16. Effect of Sweating on Insulation of Footwear.

    Science.gov (United States)

    Kuklane, Kalev; Holmér, Ingvar

    1998-01-01

    The study aimed to find out the influence of sweating on footwear insulation with a thermal foot model. Simultaneously, the influence of applied weight (35 kg), sock, and steel toe cap were studied. Water to 3 sweat glands was supplied with a pump at the rate of 10 g/hr in total. Four models of boots with steel toe caps were tested. The same models were manufactured also without steel toe. Sweating reduced footwear insulation 19-25% (30-37% in toes). During static conditions, only a minimal amount of sweat evaporated from boots. Weight affected sole insulation: Reduction depended on compressibility of sole material. The influence of steel toe varied with insulation. The method of thermal foot model appears to be a practical tool for footwear evaluation.

  17. Locally Aggressive Fibrous Dysplasia Mimicking Malign Calvarial Lesion.

    Science.gov (United States)

    Ogul, Hayri; Keskin, Emine

    2018-05-01

    Fibrous dysplasia is an unusual benign bone tumor. It is divided into 3 groups as monostotic, polyostotic, and craniofacial form. The authors reported an unusual patient with fibrous dysplasia with an aggressive radiologic appearance.

  18. Extraction of uranium from seawater by the fibrous composite adsorbent

    International Nuclear Information System (INIS)

    Katoh, Shunsaku; Sugasaka, Kazuhiko; Nogi, Tatsuo; Yoshizumi, Nobuo; Mima, Kooji.

    1986-01-01

    The fibrous composite adsorbents consisting of hydrous titanium oxide and activated carbon were prepared with hydrophilic polyacrylonitrile system polymer as a binder under various conditions, and the adsorptive property of the fibrous composite adsorbents for uranium from seawater was examined. The fibrous composite adsorbents which spun under high pressure (10 kg/cm 2 ) was the finest having the largest pore volume. In addition, the amount of uranium adsorbed of the fibrous adsorbent was the largest. The rate of uranium adsorption by the fibrous adsorbent was the same as the rate of uranium adsorption by the powdery adsorbent. The excellent fibrous adsorbent adsorbed 0.23 mg U/g adsorbent for 10 d and 0.65 mg U/g adsorbent for 100 d. The rate of uranium desorption from the fibrous adsorbent by alkali carbonate solution was large, and the uranium in the fibrous adsorbent desorbed 75 % for 8 h and about 100 % for 24 h. (author)

  19. Measure Guideline: Internal Insulation of Masonry Walls

    Energy Technology Data Exchange (ETDEWEB)

    Straube, J. F.; Ueno, K.; Schumacher, C. J.

    2012-07-01

    This measure guideline provides recommendations for interior insulation assemblies that control interstitial condensation and durability risks; recommendations for acceptable thermal performance are also provided. An illustrated guide of high-risk exterior details (which concentrate bulk water), and recommended remediation details is provided. This is followed by a recommended methodology for risk assessment of a masonry interior insulation project: a series of steps are suggested to assess the risks associated with this retrofit, with greater certainty with added steps.

  20. Measure Guideline. Internal Insulation of Masonry Walls

    Energy Technology Data Exchange (ETDEWEB)

    Straube, J. F. [Building Science Corporation (BSC), Somerville, MA (United States); Ueno, K. [Building Science Corporation (BSC), Somerville, MA (United States); Schumacher, C. J. [Building Science Corporation (BSC), Somerville, MA (United States)

    2012-07-01

    This measure guideline provides recommendations for interior insulation assemblies that control interstitial condensation and durability risks; recommendations for acceptable thermal performance are also provided. An illustrated guide of high-risk exterior details (which concentrate bulk water), and recommended remediation details is provided. This is followed by a recommended methodology for risk assessment of a masonry interior insulation project: a series of steps are suggested to assess the risks associated with this retrofit, with greater certainty with added steps.

  1. Testing Devices Garner Data on Insulation Performance

    Science.gov (United States)

    2014-01-01

    To develop a test instrument that could garner measurements of the thermal performance of insulation under extreme conditions, researchers at Kennedy Space Center devised the Cryostat 1 and then Cryostat 2. McLean, Virginia-based QinetiQ North America licensed the technology and plans to market it to organizations developing materials for things like piping and storage tank insulation, refrigeration, appliances, and consumer goods.

  2. High Performance Slab-on-Grade Foundation Insulation Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Louise F. [NorthernSTAR, St. Paul, MN (United States); Mosiman, Garrett E. [NorthernSTAR, St. Paul, MN (United States)

    2015-09-01

    ?A more accurate assessment of SOG foundation insulation energy savings than traditionally possible is now feasible. This has been enabled by advances in whole building energy simulation with 3-dimensional foundation modelling integration at each time step together with an experimental measurement of the site energy savings of SOG foundation insulation. Ten SOG insulation strategies were evaluated on a test building to identify an optimum retrofit insulation strategy in a zone 6 climate (Minneapolis, MN). The optimum insulation strategy in terms of energy savings and cost effectiveness consisted of two components: (a) R-20 XPS insulation above grade, and, (b) R-20 insulation at grade (comprising an outer layer of R-10 insulation and an interior layer of R-12 poured polyurethane insulation) tapering to R-10 XPS insulation at half the below-grade wall height (the lower half of the stem wall was uninsulated). The optimum insulation strategy was applied to single and multi-family residential buildings in climate zone 4 - 7. The highest site energy savings of 5% was realized for a single family home in Duluth, MN, and the lowest savings of 1.4 % for a 4-unit townhouse in Richmond, VA. SOG foundation insulation retrofit simple paybacks ranged from 18 to 47 years. There are other benefits of SOG foundation insulation resulting from the increase in the slab surface temperatures. These include increased occupant thermal comfort, and a decrease in slab surface condensation particularly around the slab perimeter.

  3. [Fibrous dysplasia of the frontal sinus: a case report].

    Science.gov (United States)

    Keleş, Erol; Kaplama, Mehmet Erkan; Ozkara, Sule; Cobanoğlu, Bengü

    2011-01-01

    Fibrous dysplasia is a rare and indolent benign tumor of bone. Although it is a benign tumor, it has malignant transformation potential. Fibrous dysplasia can involve a single or multiple bones. The maxilla and mandible are the most common sites in the head and neck region. Paranasal sinus involvement is rare. Surgical excision is the preferred treatment of patients with symptomatic fibrous dysplasia. In this article, a 54-year-old male patient diagnosed with fibrous dysplasia of the frontal bone is presented.

  4. Evaluation and histological maturation characteristics of fibrous ...

    African Journals Online (AJOL)

    Evaluation and histological maturation characteristics of fibrous dysplasia and ossifying fibroma: a case series. ... diagnosed as OF and FD were retrieved from the archival records of the Departments of Oral Surgery/Oral Pathology and Histopathology/Morbid Anatomy, Muhimbili University of Health and Allied Sciences.

  5. Steam Reformer With Fibrous Catalytic Combustor

    Science.gov (United States)

    Voecks, Gerald E.

    1987-01-01

    Proposed steam-reforming reactor derives heat from internal combustion on fibrous catalyst. Supplies of fuel and air to combustor controlled to meet demand for heat for steam-reforming reaction. Enables use of less expensive reactor-tube material by limiting temperature to value safe for material yet not so low as to reduce reactor efficiency.

  6. Apparatus for processing fibrous pulp material

    NARCIS (Netherlands)

    Dekker, J.C.; Bouma, H.; Mulder, F.B.M.

    2008-01-01

    The invention relates to an apparatus (1) for processing a flow of pulp comprising fibrous material, in particular pulp comprising cellulose fibres for making paper, said apparatus comprising a drum (2) having a rotational axis (R), an inlet end (3), an outlet end (4) and an inner surface, a

  7. MRI of intracranial meningeal malignant fibrous histiocytoma

    International Nuclear Information System (INIS)

    Ogino, A.; Ochi, M.; Hayashi, K.; Hirata, K.; Hayashi, T.; Yasunaga, A.; Shibata, S.

    1996-01-01

    We describe the CT and MRI findings in a patient with primary intracranial meningeal malignant fibrous histiocytoma (MFH). CT delineated the anatomical relations and MRI aided in tissue characterisation. To our knowledge, this is the first report describing the MRI findings in primary intracranial meningeal MFH. (orig.). With 1 fig

  8. Automated measurement of thermal conductivity

    Science.gov (United States)

    Hale, D. V.

    1969-01-01

    Testing technique permits accurate measurement of temperature-dependent thermal conductivity, by virtue of the small temperature differential required across a specimen. The permissible mean insulation temperature ranges from cryogenic to 10 degrees F for the insulation under test.

  9. 7 CFR 2902.17 - Plastic insulating foam for residential and commercial construction.

    Science.gov (United States)

    2010-01-01

    ... Protection Agency designated building insulation containing recovered materials as items for which Federal... building insulation products in the Recovered Materials Advisory Notice (RMAN) published for these products... provide a sealed thermal barrier for residential or commercial construction applications. (b) Minimum...

  10. Acoustic excitation of containment insulation cover plate

    International Nuclear Information System (INIS)

    Fenech, H.; Rao, A.K.

    1978-01-01

    An experimental and theoretical program has been implemented by NRC-BNL since 1975 at the University of California, Santa Barbara to assess the reliability of the PCRV thermal insulation cover plate and the possible safety problem caused by the failure of this plate. A typical large HTGR PCRV unit [1160 MW(e)] and thermal insulation class A were selected. The upper core cavity is estimated to be the most critical volume where the noise pressure levels are expected to reach 110 to 130 dB (rel. to 2 x 10 -4 dynes/cm 2 ). The noise spectrum in that cavity is a composite of circulator noise, vortex shedding boundary layer turbulence, and flow impingement. Some anticipated safety related problems associated with the thermal insulation failure are examined

  11. Thermal Clothing

    Science.gov (United States)

    1997-01-01

    Gateway Technologies, Inc. is marketing and developing textile insulation technology originally developed by Triangle Research and Development Corporation. The enhanced thermal insulation stems from Small Business Innovation Research contracts from NASA's Johnson Space Center and the U.S. Air Force. The effectiveness of the insulation comes from the microencapsulated phase-change materials originally made to keep astronauts gloved hands warm. The applications for the product range from outer wear, housing insulation, and blankets to protective firefighting gear and scuba diving suits. Gateway has developed and begun marketing thermal regulating products under the trademark, OUTLAST. Products made from OUTLAST are already on the market, including boot and shoe liners, winter headgear, hats and caps for hunting and other outdoor sports, and a variety of men's and women's ski gloves.

  12. Cryogenic Vacuum Insulation for Vessels and Piping

    Science.gov (United States)

    Kogan, A.; Fesmire, J.; Johnson, W.; Minnick, J.

    2010-01-01

    Cryogenic vacuum insulation systems, with proper materials selection and execution, can offer the highest levels of thermal performance. Three areas of consideration are vital to achieve the optimum result: materials, representative test conditions, and engineering approach for the particular application. Deficiency in one of these three areas can prevent optimum performance and lead to severe inefficiency. Materials of interest include micro-fiberglass, multilayer insulation, and composite arrangements. Cylindrical liquid nitrogen boil-off calorimetry methods were used. The need for standard thermal conductivity data is addressed through baseline testing. Engineering analysis and design factors such as layer thickness, density, and practicality are also considered.

  13. Isolated fibrous dysplasia of the ethmoid sinus

    Directory of Open Access Journals (Sweden)

    Alper Yenigun

    2015-01-01

    Full Text Available Fibrous dysplasia is a benign fibro-osseous lesion progressing with one or more bone involvements in the skeleton. Even though it is a benign tumor, it may potentially transform into a malignant one. While the most frequently involved zones in the head–neck zone include the maxilla, mandible, parietal, occipital, and temporal zones, the involvement of the ethmoid bone is rather rare. This article presents the case of a female patient who was diagnosed with fibrous dysplasia in the right ethmoid sinus based on the paranasal computerized tomography scan that was taken due to the symptoms of pain around the right eye, pressure, and a feeling of being pushed.

  14. Monostotic fibrous dysplasia with Raynaud's phenomenon.

    Science.gov (United States)

    Kumar, K V S Hari; Aravinda, K; Narayanan, K

    2015-01-01

    Fibrous dysplasia (FD) is a benign bone disorder characterized by alteration in bone morphology. Monostotic FD is the commonest variant and affects the craniofacial bones. Raynaud's phenomenon is recurrent vasospasm of the fingers and toes due to cold exposure. The disease is usually idiopathic or secondary to connective tissue disorders. Raynaud's phenomenon is not described previously with FD. We recently encountered two interesting patients of craniofacial monostotic FD with Raynaud's phenomenon and report the same in this report.

  15. Fibrous dysplasia of the paranasal sinuses.

    Science.gov (United States)

    Feldman, M D; Rao, V M; Lowry, L D; Kelly, M

    1986-09-01

    Fibrous dysplasia (FD) of the paranasal sinuses is rare and often presents a diagnostic challenge. It is usually secondary to extension of disease from adjacent bones and is rarely limited to the sinuses. We have described three cases of FD involving the paranasal sinuses, including the first reported case of FD isolated to the sphenoid sinus. A brief update of the clinical aspects, radiographic appearance, diagnosis, and management of craniofacial FD is provided.

  16. High surface area fibrous silica nanoparticles

    KAUST Repository

    Polshettiwar, Vivek

    2014-11-11

    Disclosed are high surface area nanoparticles that have a fibrous morphology. The nanoparticles have a plurality of fibers, wherein each fiber is in contact with one other fiber and each fiber has a length of between about 1 nm and about 5000 nm. Also disclosed are applications of the nanoparticles of the present invention, and methods of fabrication of the nanoparticles of the present invention.

  17. Complementary scintigraphy in polyostotic fibrous dysplasia

    International Nuclear Information System (INIS)

    Murray, I.P.C.; Haindl, W.; Frater, C.J.

    1996-01-01

    A 65-year-old man with a long history of right knee pain complained of discomfort in both hips. An X-ray has identified changes in the pelvis to indicate Paget's disease. Bone scintigraphy after administration of thallium-201 was performed to ascertain the extent of this disorder. The whole body sweep showed multiple areas of abnormal uptake of varying size and intensity. This finding excluded the possibility of malignant change such as osteogenic sarcoma and malignant fibrous hystiocytoma . 2 figs

  18. Postirradiation sarcoma (malignant fibrous histiocytoma) of axilla

    International Nuclear Information System (INIS)

    Hardy, T.J.; An, T.; Brown, P.W.; Terz, J.J.

    1978-01-01

    A case is reported of a patient who developed a histologically unusual sarcoma in the axilla and chest wall 8 years after receiving radiation therapy (6500 rad) for carcinoma of the breast. This sarcoma showed light- and electron-microscopic features of a malignant fibrous histiocytoma, a tumor not documented among 24 previously reported cases of postirradiation sarcoma following the diagnosis of breast carcinoma. In addition, the literature is reviewed and discussed regarding postirradiation sarcoma in general following breast carcinoma

  19. A time-resolved current method and TSC under vacuum conditions of SEM: Trapping and detrapping processes in thermal aged XLPE insulation cables

    Science.gov (United States)

    Boukezzi, L.; Rondot, S.; Jbara, O.; Boubakeur, A.

    2017-03-01

    Thermal aging of cross-linked polyethylene (XLPE) can cause serious concerns in the safety operation in high voltage system. To get a more detailed picture on the effect of thermal aging on the trapping and detrapping process of XLPE in the melting temperature range, Thermal Stimulated Current (TSC) have been implemented in a Scanning Electron Microscope (SEM) with a specific arrangement. The XLPE specimens are molded and aged at two temperatures (120 °C and 140 °C) situated close to the melting temperature of the material. The use of SEM allows us to measure both leakage and displacement currents induced in samples under electron irradiation. The first represents the conduction process of XLPE and the second gives information on the trapping of charges in the bulk of the material. TSC associated to the SEM leads to show spectra of XLPE discharge under thermal stimulation using both currents measured after electron irradiation. It was found that leakage current in the charging process may be related to the physical defects resulting in crystallinity variation under thermal aging. However the trapped charge can be affected by the carbonyl groups resulting from the thermo-oxidation degradation and the disorder in the material. It is evidenced from the TSC spectra of unaged XLPE that there is no detrapping charge under heat stimulation. Whereas the presence of peaks in the TSC spectra of thermally aged samples indicates that there is some amount of trapped charge released by heating. The detrapping behavior of aged XLPE is supported by the supposition of the existence of two trap levels: shallow traps and deep traps. Overall, physico-chemical reactions under thermal aging at high temperatures leads to the enhancement of shallow traps density and changes in range of traps depth. These changes induce degradation of electrical properties of XLPE.

  20. Compact gas-insulated transformer. Fourteenth quarterly report

    Energy Technology Data Exchange (ETDEWEB)

    1983-08-01

    Objective is to develop a compact, more efficient, quieter transformer which does not rely on mineral oil insulation. Compressed SF/sub 6/ is used as the external insulation and polymer film as the insulation between turns. A separate liquid cooling system is also provided. This document reports progress made in design, mechanical, dielectric, short circuit, thermal, materials, prototype, accessories, commercialization, and system studies. (DLC)

  1. Toxicity and Carcinogenicity Mechanisms of Fibrous Antigorite

    Directory of Open Access Journals (Sweden)

    Michael Balazy

    2007-03-01

    Full Text Available We studied the effects of fibrous antigorite on mesothelial MeT-5A and monocyte-macrophage J774 cell lines to further understand cellular mechanisms induced by asbestos fibers leading to lung damage and cancer. Antigorite is a mineral with asbestiform properties, which tends to associate with chrysotile or tremolite, and frequently occurs as the predominant mineral in the veins of several serpentinite rocks found abundantly in the Western Alps. Particles containing antigorite are more abundant in the breathing air of this region than those typically found in urban ambient air. Exposure of MeT-5A and J774 cells to fibrous antigorite at concentrations of 5-100 μg/ml for 72 hr induced dose-dependent cytotoxicity. Antigorite also stimulated the ROS production, induced the generation of nitrite and PGE2. MeT-5A cells were more sensitive to antigorite than J774 cells. The results of this study revealed that the fibrous antigorite stimulates cyclooxygenase and formation of hydroxyl and nitric oxide radicals. These changes represent early cellular responses to antigorite fibers, which lead to a host of pathological and neoplastic conditions because free radicals and PGE2 play important roles as mediators of tumor pathogenesis. Understanding the mechanisms of the cellular responses to antigorite and other asbestos particles should be helpful in designing rational prevention and treatment approaches.

  2. Fibrous zinc anodes for high power batteries

    Science.gov (United States)

    Zhang, X. Gregory

    This paper introduces newly developed solid zinc anodes using fibrous material for high power applications in alkaline and large size zinc-air battery systems. The improved performance of the anodes in these two battery systems is demonstrated. The possibilities for control of electrode porosity and for anode/battery design using fibrous materials are discussed in light of experimental data. Because of its mechanical integrity and connectivity, the fibrous solid anode has good electrical conductivity, mechanical stability, and design flexibility for controlling mass distribution, porosity and effective surface area. Experimental data indicated that alkaline cells made of such anodes can have a larger capacity at high discharging currents than commercially available cells. It showed even greater improvement over commercial cells with a non-conventional cell design. Large capacity anodes for a zinc-air battery have also been made and have shown excellent material utilization at various discharge rates. The zinc-air battery was used to power an electric bicycle and demonstrated good results.

  3. Dissolving behavior and calcium release from fibrous wollastonite in acetic acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Ptacek, Petr, E-mail: ptacek@fch.vutbr.cz [Institute of Materials Science, Faculty of Chemistry, Brno University of Technology, Purkynova 464/118, Brno CZ-621 00 (Czech Republic); Noskova, Magdalena; Brandstetr, Jiri; Soukal, Frantisek; Opravil, Tomas [Institute of Materials Science, Faculty of Chemistry, Brno University of Technology, Purkynova 464/118, Brno CZ-621 00 (Czech Republic)

    2010-01-20

    The degradability of fibrous wollastonite (CaSiO{sub 3}) in an aqueous solution of acetic acid and leaching of Ca{sup 2+} ions were investigated in the temperature range from 22 to 50 {sup o}C. The Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-OES) was used for the assessment of calcium and other selected cations in the leaching medium. The amount of calcium in the solvent can be significantly enhanced through leaching at higher temperature. Fibrous silica particles are the main by-product of the leaching process. The properties of by-product were examined by thermal analysis (simultaneous TG-DTA-EGA), infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The formation of silica layer on the surface of fibrous wollastonite particles is an important factor in the leaching process. Particles were covered by the silica layer and wollastonite core size was continually decreasing during leaching. The shape of resulting silica particles shows no significant changes during this process. Specific surface of the formed fibrous silica particles strongly depends on the leaching temperature.

  4. Electro spun Polyamide 4.6 Nano fibrous Nonwoven: Parameter Study and Characterization

    International Nuclear Information System (INIS)

    Schoenmaker, B.De.; Schueren, L.V.; Ceylan, O.; Clerck, K.De.

    2012-01-01

    The aliphatic polyamide 4.6 (PA 4.6) has unique properties compared to the commonly used polyamides 6 (PA 6) and 6.6 (PA 6.6). The purpose of this paper is to produce uniform and reproducible nano fibrous PA 4.6 structures. Therefore, a mixture of the solvent formic acid and the non solvent acetic acid is used to dissolve and electro spin the PA 4.6. First the steady-state behaviour of the process and the boundary limits of the solution parameters needed for steady-state electro spinning are investigated. Subsequently, the effect of several solution and process parameters on the fibre morphology is examined, using microscopic techniques and thermal analysis. The polyamide concentration is found to be the dominant parameter affecting the fibre diameter and morphology. Furthermore, tensile tests are performed on up scaled nano fibrous structures and electro spun under optimised steady-state conditions. It is shown that the PA 4.6 nano fibrous structures, compared to nano fibrous nonwoven s of PA 6 and PA 6.6, have a higher stress and strain at break.

  5. Metallic insulation transport and strainer clogging tests

    International Nuclear Information System (INIS)

    Hyvaerinen, J.; Hongisto, O.

    1994-06-01

    Experiments to probe the transport and clogging properties of metallic (metal reflective) insulation have been carried out in order to provide data for evaluation of their influence on the emergency core cooling and containment spray systems of the Finnish boiling water reactors in the event of a design basis accident. The specific metallic insulation tested was DARMET, provided by Darchem Engineering Ltd. The inner foils of Darmet are dimped. Available literature on the metallic insulation performance under design basis accident conditions has been reviewed. On the basis of the review a parametric approach has been chosen for the transport and clogging experiments. This approach involves testing a wide size range of various shapes of foil pieces. Five sets of experiments have been carried out. The first three sets investigate transport properties of the foil pieces, starting from sedimentation in stagnant waste pool and proceeding to transport in horizontal and vertically circulating flows. The clogging experiments have been addressed the differential pressures obtained due to accumulation of both pure and metallic and a mixture of metallic and fibrous (mineral wool) depris. (4 refs., 24 figs., 2 tabs.)

  6. High temperature structural insulating material

    Science.gov (United States)

    Chen, W.Y.

    1984-07-27

    A high temperature structural insulating material useful as a liner for cylinders of high temperature engines through the favorable combination of high service temperature (above about 800/sup 0/C), low thermal conductivity (below about 0.2 W/m/sup 0/C), and high compressive strength (above about 250 psi). The insulating material is produced by selecting hollow ceramic beads with a softening temperature above about 800/sup 0/C, a diameter within the range of 20-200 ..mu..m, and a wall thickness in the range of about 2 to 4 ..mu..m; compacting the beads and a compatible silicate binder composition under pressure and sintering conditions to provide the desired structural form with the structure having a closed-cell, compact array of bonded beads.

  7. Aerogel Blanket Insulation Materials for Cryogenic Applications

    Science.gov (United States)

    Coffman, B. E.; Fesmire, J. E.; White, S.; Gould, G.; Augustynowicz, S.

    2009-01-01

    Aerogel blanket materials for use in thermal insulation systems are now commercially available and implemented by industry. Prototype aerogel blanket materials were presented at the Cryogenic Engineering Conference in 1997 and by 2004 had progressed to full commercial production by Aspen Aerogels. Today, this new technology material is providing superior energy efficiencies and enabling new design approaches for more cost effective cryogenic systems. Aerogel processing technology and methods are continuing to improve, offering a tailor-able array of product formulations for many different thermal and environmental requirements. Many different varieties and combinations of aerogel blankets have been characterized using insulation test cryostats at the Cryogenics Test Laboratory of NASA Kennedy Space Center. Detailed thermal conductivity data for a select group of materials are presented for engineering use. Heat transfer evaluations for the entire vacuum pressure range, including ambient conditions, are given. Examples of current cryogenic applications of aerogel blanket insulation are also given. KEYWORDS: Cryogenic tanks, thermal insulation, composite materials, aerogel, thermal conductivity, liquid nitrogen boil-off

  8. Structural Behavior of Fibrous Reinforced Concrete Hollow Core One-Way Slabs Strengthening by C.F.R.P

    Directory of Open Access Journals (Sweden)

    وصيف مجيد

    2016-02-01

    Full Text Available A reinforced concrete hollow core one-way slab is one of the types of slabs used widely around the world in residential and industrial buildings to take advantage of them Economic and thermal insulation as well as to reduce the self-weight of the construction. The aim of the present study is to examine the structural behavior of the reinforced concrete hollow core one-way slabs reduce failure using the normal concrete and fibrous concrete and then strengthened using carbon fiber(CFRPThis study include molding of ( 6 specimens differ in terms of the voids volume (Vv , volumetric percentage of steel fibers (ا, and then strengthened by using fibers of carbon , with the aim of rehabilitation by fibers, carbon polymer (CFRP is to find out how efficient element structural when treated after the occurrence of the failure and the validity of its use in the event of a failure has occurred entirely or partly in the roof, and re- examined using the same method and conditions that were examined ceilings is affected through it, knowing that these ceilings have been addressed and strengthened in the same way , the results of the tests of the models that have been rehabilitated using carbon fiber (CFRP, compared with the same models before strengthening and examined reduce failure, increased very high susceptibility endurance extreme , with the increase ranging from (51.6% to (96.2%, as has been observed decrease in deflection value of models after strengthening by (CFRP.It is concluded through this study the possibility of using its concrete hollow core one-way slab as a roofing system for buildings also proved the highly efficient for this slab after rehabilitation using carbon fiber (CFRP.

  9. Seasonal shading of walls with transparent thermal insulation by means of prismatic panes; Saisonale Abschattung von transparent gedaemmten Waenden mit Hilfe von Prismenscheiben

    Energy Technology Data Exchange (ETDEWEB)

    Christoffers, D.; Kneser, P.; Schramm, U. [Institut fuer Solarenergieforschung GmbH Hameln/Emmerthal (ISFH), Emmerthal (Germany). Abt. Systemtechnik von Solaranlagen

    1998-02-01

    Using prismatic panes, a seasonal shading responsive to the sun`s position can be realized. Thus the solar gains from direct radiation can be closely matched to the annual pattern of the heating requirements of buildings. The panes are suitable for window or facade elements in applications which do not need transparency insulated walls. The direct radiation received on a vertical south-oriented facade is reduced to 10% on clear summer days, while 90% is transmitted on clear winter days. The paper reports on results from computer simulations and experiences from a one year field test. (orig.) [Deutsch] Mit Hilfe von Prismenscheiben kann eine sonnenstandsabhaengige, saisonale Verschattung realisiert werden. Damit lassen sich solare Gewinne aus direkter Einstrahlung sehr gut an den jaehrlichen Verlauf des Heizenergiebedarfs von Gebaeuden anpassen. Sie eignen sich als nach Sueden weisende Fenster- und Fassadenelemente vorzugsweise in Bereichen, die keinen freien Durchblick benoetigen, insbesondere auch fuer transparent gedaemmte Solarwaende. Die auf die Suedfassade treffende Direktstrahlung wird durch die Prismenscheibe an klaren Wintertagen auf etwa 90%, an klaren Sommertagen auf 10% reduziert. Der Beitrag beschreibt die Ergebnisse von Simulationsrechnungen und die Erfahrungen aus einem einjaehrigen Praxistest. (orig.)

  10. In-situ thermal annealing of on-membrane silicon-on-insulator semiconductor-based devices after high gamma dose irradiation.

    Science.gov (United States)

    Amor, S; André, N; Kilchytska, V; Tounsi, F; Mezghani, B; Gérard, P; Ali, Z; Udrea, F; Flandre, D; Francis, L A

    2017-05-05

    In this paper, we investigate the recovery of some semiconductor-based components, such as N/P-type field-effect transistors (FETs) and a complementary metal-oxide-semiconductor (CMOS) inverter, after being exposed to a high total dose of gamma ray radiation. The employed method consists mainly of a rapid, low power and in situ annealing mitigation technique by silicon-on-insulator micro-hotplates. Due to the ionizing effect of the gamma irradiation, the threshold voltages showed an average shift of -580 mV for N-channel transistors, and -360 mV for P-MOSFETs. A 4 min double-cycle annealing of components with a heater temperature up to 465 °C, corresponding to a maximum power of 38 mW, ensured partial recovery but was not sufficient for full recovery. The degradation was completely recovered after the use of a built-in high temperature annealing process, up to 975 °C for 8 min corresponding to a maximum power of 112 mW, which restored the normal operating characteristics for all devices after their irradiation.

  11. Insulation Test Cryostat with Lift Mechanism

    Science.gov (United States)

    Fesmire, James E. (Inventor); Dokos, Adam G. (Inventor)

    2016-01-01

    A multi-purpose, cylindrical thermal insulation test apparatus is used for testing insulation materials and systems of materials using a liquid boil-off calorimeter system for absolute measurement of the effective thermal conductivity (k-value) and heat flux of a specimen material at a fixed environmental condition (cold-side temperature, warm-side temperature, vacuum pressure level, and residual gas composition). An inner vessel receives liquid with a normal boiling point below ambient temperature, such as liquid nitrogen, enclosed within a vacuum chamber. A cold mass assembly, including upper and lower guard chambers and middle test vessel, is suspended from a lid of the vacuum canister. Each of the three chambers is filled and vented through a single feedthrough. All fluid and instrumentation feedthroughs are mounted and suspended from a top domed lid allowing easy removal of the cold mass. A lift mechanism allows manipulation of the cold mass assembly and insulation test article.

  12. Electrochemical characterization of electrospun nanocomposite polymer blend electrolyte fibrous membrane for lithium battery.

    Science.gov (United States)

    Padmaraj, O; Rao, B Nageswara; Venkateswarlu, M; Satyanarayana, N

    2015-04-23

    Novel hybrid (organic/inorganic) electrospun nanocomposite polymer blend electrolyte fibrous membranes with the composition poly(vinylidene difluoride-co-hexafluoropropylene) [P(VdF-co-HFP)]/poly(methyl methacrylate) [P(MMA)]/magnesium aluminate (MgAl2O4)/LiPF6 were prepared by the electrospinning technique. All of the prepared electrospun P(VdF-co-HFP), PMMA blend [90% P(VdF-co-HFP)/10% PMMA], and nanocomposite polymer blend [90% P(VdF-co-HFP)/10% PMMA/x wt % MgAl2O4 (x = 2, 4, 6, and 8)] fibrous membranes were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. The fibrous nanocomposite separator-cum-polymer blend electrolyte membranes were obtained by soaking the nanocomposite polymer blend membranes in an electrolyte solution containing 1 M LiPF6 in ethylene carbonate (EC)/diethyl carbonate (DEC) (1:1, v/v). The newly developed fibrous nanocomposite polymer blend electrolyte [90% P(VdF-co-HFP)/10% PMMA/6 wt % MgAl2O4/LiPF6] membrane showed a low crystallinity, low average fiber diameter, high thermal stability, high electrolyte uptake, high conductivity (2.60 × 10(-3) S cm(-1)) at room temperature, and good potential stability above 4.5 V. The best properties of the fibrous nanocomposite polymer blend electrolyte (NCPBE) membrane with a 6 wt % MgAl2O4 filler content was used for the fabrication of a Li/NCPBE/LiCoO2 CR 2032 coin cell. The electrochemical performance of the fabricated CR 2032 cell was evaluated at a current density of 0.1 C-rate. The fabricated CR 2032 cell lithium battery using the newly developed NCPBE membrane delivered an initial discharge capacity of 166 mAh g(-1) and a stable cycle performance.

  13. Fibrous dysplasia of the maxillary sinus: case report

    OpenAIRE

    Vijayalakshmi Subramaniam; Adarsha Tuluvinakoppa Vasudeva Herle

    2010-01-01

    Introduction and objective: Fibrous dysplasia is a non-neoplastic lesion of unknown origin with one-fourth involving head and neck. The aim of this paper is to report a case of fibrous dysplasia of the maxillary sinus, describing its clinical presentation, radiological features, histopathological appearance and surgical management. Case report: 3-year-old female patient who presented with a history of fullness of the right cheek and intraoral swelling was diagnosed to have fibrous dysplasia o...

  14. Postirradiation sarcoma (malignant fibrous histiocytoma) following cervix cancer

    International Nuclear Information System (INIS)

    Pinkston, J.A.; Sekine, Ichiro.

    1980-12-01

    A case of postirradiation sarcoma is described. The tumor, a malignant fibrous histiocytoma, occurred in the radiation field 11 years following postoperative external beam radiation therapy (7,000 rad) for carcinoma of the cervix. Reports of postirradiation malignant fibrous histiocytoma are rare, and the occurrence of this neoplasm following treatment for cervix cancer has not previously been described. The literature concerning postirradiation bone and soft tissue sarcomas is briefly reviewed, with special attention to malignant fibrous histiocytomas. (author)

  15. Characterization of Microporous Insulation, Microsil

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-06-15

    Microsil microporous insulation has been characterized by Lawrence Livermore National Laboratory for possible use in structural and thermal applications in the DPP-1 design. Qualitative test results have provided mechanical behavioral characteristics for DPP-1 design studies and focused on the material behavioral response to being crushed, cyclically loaded, and subjected to vibration for a confined material with an interference fit or a radial gap. Quantitative test results have provided data to support the DPP-1 FEA model analysis and verification and were used to determine mechanical property values for the material under a compression load. The test results are documented within this report.

  16. Strongly Correlated Topological Insulators

    Science.gov (United States)

    2016-02-03

    Strongly Correlated Topological Insulators In the past year, the grant was used for work in the field of topological phases, with emphasis on finding...surface of topological insulators. In the past 3 years, we have started a new direction, that of fractional topological insulators. These are materials...in which a topologically nontrivial quasi-flat band is fractionally filled and then subject to strong interactions. The views, opinions and/or

  17. Exploring Homeowners’ Insulation Activity

    OpenAIRE

    Friege, J; Holtz, G; Chappin, E.J.L.

    2016-01-01

    Insulating existing buildings offers great potential for reducing greenhouse gas emissions and meeting Germany’s climate protection targets. Previous research suggests that, since homeowners’ decision-making processes are inadequately understood as yet, today’s incentives aiming at increasing insulation activity lead to unsatisfactory results. We developed an agent-based model to foster the understanding of homeowners’ decision-making processes regarding insulation and to explore how situatio...

  18. Malignant solitary fibrous tumor metastatic to the orbit.

    Science.gov (United States)

    Glazer-Hockstein, Carolyn; Syed, Nasreen A; Warhol, Michael; Gausas, Roberta E

    2004-11-01

    A 61-year-old man with a history of malignant solitary fibrous tumor of the chest had development of unusual sites of metastasis involving the sphenoid wing of the orbit and soft tissues of the cheek. He was found to have a solitary fibrous tumor, an uncommon type of spindle cell neoplasm that most often arises in the pleura, which was metastatic to the orbit. This is the first reported case of malignant solitary fibrous tumor metastatic to the orbit. The clinical and histopathologic findings of metastatic malignant solitary fibrous tumor are described.

  19. Fibrous composites comprising carbon nanotubes and silica

    Science.gov (United States)

    Peng, Huisheng [Shanghai, CN; Zhu, Yuntian Theodore [Cary, NC; Peterson, Dean E [Los Alamos, NM; Jia, Quanxi [Los Alamos, NM

    2011-10-11

    Fibrous composite comprising a plurality of carbon nanotubes; and a silica-containing moiety having one of the structures: (SiO).sub.3Si--(CH.sub.2).sub.n--NR.sub.1R.sub.2) or (SiO).sub.3Si--(CH.sub.2).sub.n--NCO; where n is from 1 to 6, and R.sub.1 and R.sub.2 are each independently H, CH.sub.3, or C.sub.2H.sub.5.

  20. Plasmonics in Topological Insulators

    Directory of Open Access Journals (Sweden)

    Yi-Ping Lai

    2014-04-01

    Full Text Available With strong spin-orbit coupling, topological insulators have an insulating bulk state, characterized by a band gap, and a conducting surface state, characterized by a Dirac cone. Plasmons in topological insulators show high frequency-tunability in the mid-infrared and terahertz spectral regions with transverse spin oscillations, also called “spin-plasmons”. This paper presents a discussion and review of the developments in this field from the fundamental theory of plasmons in bulk, thin-film, and surface-magnetized topological insulators to the techniques of plasmon excitation and future applications.