WorldWideScience

Sample records for insulating materials

  1. Insulating materials for optoelectronics

    International Nuclear Information System (INIS)

    Agullo-Lopez, F.

    1990-01-01

    Optoelectronics is an interdisciplinary field. Basic functions of an optoelectronic system include the generator of the optical signal, its transmission and handling and, finally, its detection, storage and display. A large variety of semiconductor and insulating materials are used or are being considered to perform those functions. The authors focus on insulating materials, mostly oxides. For signal generation, tunable solid state lasers, either vibronic or those based oon colour centres are briefly described, and their main operating parameters summarized. Reference is made to some developments on fiber and waveguide lasers. Relevant physical features of the silica fibres used for low-loss, long-band, optical transmission are reviewed, as well as present efforts to further reduce attenuation in the mid-infrared range. Particular attention is paid to photorefractive materials (LiNbO 3 , BGO, BSO, etc.), which are being investigated

  2. Plastic Materials for Insulating Applications.

    Science.gov (United States)

    Wang, S. F.; Grossman, S. J.

    1987-01-01

    Discusses the production and use of polymer materials as thermal insulators. Lists several materials that provide varying degrees of insulation. Describes the production of polymer foam and focuses on the major applications of polystyrene foam, polyurethane foam, and polyisocyanurate foam. (TW)

  3. Positron Annihilation in Insulating Materials

    International Nuclear Information System (INIS)

    Asoka-Kumar, P; Sterne, PA

    2002-01-01

    We describe positron results from a wide range of insulating materials. We have completed positron experiments on a range of zeolite-y samples, KDP crystals, alkali halides and laser damaged SiO 2 . Present theoretical understanding of positron behavior in insulators is incomplete and our combined theoretical and experimental approach is aimed at developing a predictive understanding of positrons and positronium annihilation characteristics in insulators. Results from alkali halides and alkaline-earth halides show that positrons annihilate with only the halide ions, with no apparent contribution from the alkali or alkaline-earth cations. This contradicts the results of our existing theory for metals, which predicts roughly equal annihilation contributions from cation and anion. We also present result obtained using Munich positron microprobe on laser damaged SiO 2 samples

  4. Handleable shapes of thermal insulation material

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, J. T.

    1989-01-17

    Handleable and machineable shapes of thermal insulation material are made by compacting finely divided thermal insulation material into the cells of a reinforcing honeycomb insulation material into the cells of a reinforcing honeycomb structure. The finely divided thermal insulation material may be, for example, silica aerogel, pyrogenic silica, carbon black, silica gel, volatilised silica, calcium silicate, vermiculate or perlite, or finely divided metal oxides such as alumina or titania. The finely divided thermal insulation material may include an infra-red opacifier and/or reinforcing fibres. The reinforcing honeycomb structure may be made from, for example, metals such as aluminium foil, inorganic materials such as ceramics, organic materials such as plastics materials, woven fabrics or paper. A rigidiser may be employed. The shapes of thermal insulation material are substantially rigid and may be machines, for example by mechanical or laser cutting devices, or may be formed, for example by rolling, into curved or other shaped materials. 12 figs.

  5. 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....... This paper gives a comparison of systems with mineral wool and cellular plastic, based on experience from practice and literature. It is important to look at the details in the system and at long time stability of the properties such as thermal insulation, moisture and fire. Investigation of fire properties...

  6. 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.

  7. Insulating materials resistance in intense radiation beams

    International Nuclear Information System (INIS)

    Oproiu, Constantin; Martin, Diana; Scarlat, Florin; Timus, Dan; Brasoveanu, Mirela; Nemtanu, Monica

    2002-01-01

    The paper emphasizes the main changes of the mechanical and electrical properties of some organic insulating materials exposed to accelerated electron beams. These materials are liable to be used in nuclear plants and particle accelerators. The principal mechanical and electrical properties analyzed were: tensile strength, fracture strength, tearing on fracture, dielectric strength, electrical resistivity, dielectric constant and tangent angle of dielectric losses. (authors)

  8. Effects of radiation on insulation materials

    International Nuclear Information System (INIS)

    Poehlchen, R.

    1992-01-01

    This presentation will concentrate on the insulation materials which are suitable for the insulation of superconducting magnets for fusion. For the next generation of fusion machines with magnetic confinement as NET and ITER general agreement exists that the insulation will consist of fibre reinforced organic matrix material, a composite. Much effort has been put into the investigation of the radiation resistance of such materials during the last 20-30 years, see in particular the numerous reports of accelerator laboratories on this subject. But very few of the published data are relevant for the superconducting magnets of fusion machines. Either the irradiation and testing was carried out at RT or LN 2 temperature and/or the irradiation spectrum was not representative for a fusion machine and/or the materials investigated are not applicable for the insulation of S.C. fusion magnets. Therefore test programs have been launched recently, one by the NET team. The intention of the first chapter is to give guidance on the choice of materials which are suitable as insulation materials from a more general point of view. A good understanding of the coil manufacturing process is needed for this purpose. The second chapter explains the irradiation spectrum seen by the magnets. A third chapter does present the NET/ITER test programme. Step 1 was completed at the end of 1989, the second step will be carried out in the autumn of 1991. Finally, a general assessment of materials and testing methods will be given with recommendations for further testing

  9. Plasma immersion ion implantation into insulating materials

    International Nuclear Information System (INIS)

    Tian Xiubo; Yang Shiqin

    2006-01-01

    Plasma immersion ion implantation (PIII) is an effective surface modification tool. During PIII processes, the objects to be treated are immersed in plasmas and then biased to negative potential. Consequently the plasma sheath forms and ion implantation may be performed. The pre-requirement of plasma implantation is that the object is conductive. So it seems difficult to treat the insulating materials. The paper focuses on the possibilities of plasma implantation into insulting materials and presents some examples. (authors)

  10. Tests on irradiated magnet-insulator materials

    International Nuclear Information System (INIS)

    Schmunk, R.E.; Miller, L.G.; Becker, H.

    1983-01-01

    Fusion-reactor coils, located in areas where they will be only partially shielded, must be fabricated from materials which are as resistant to radiation as possible. They will probably incorporate resistive conductors with either water or cryogenic cooling. Inorganic insulators have been recommended for these situations, but the possibility exists that some organic insulators may be usuable as well. Results were previously reported for irradiation and testing of three glass reinforced epoxies: G-7, G-10, and G-11. Thin disks of these materials, nominally 0.5 mm thick by 11.1 mm diameter, were tested in compressive fatigue, a configuration and loading which represents reasonably well the magnet environment. In that work G-10 was shown to withstand repeated loading to moderately high stress levels without failure, and the material survived better at liquid nitrogen temperature than at room temperature

  11. Moisture buffer capacity of different insulation materials

    DEFF Research Database (Denmark)

    Peuhkuri, Ruut Hannele; Rode, Carsten; Hansen, Kurt Kielsgaard

    2004-01-01

    . In the isothermal tests the material samples were exposed to the same change in the relative humidity of the ambient air on both sides, while the samples were exposed to variations in relative humidity only on the cold side in the non-isothermal tests. The results of these rather different measurement principles...... lead to more durable constructions. In this paper, a large range of very different thermal insulation materials have been tested in specially constructed laboratory facilities to determine their moisture buffer capacity. Both isothermal and nonisothermal experimental set-ups have been used...... are discussed, and different ways are presented how to determine the moisture buffer capacity of the materials using partly standard material parameters and partly parameters determined from the actual measurements. The results so far show that the determination of moisture buffer capacity is very sensitive...

  12. Polyester Apparel Cutting Waste as Insulation Material

    OpenAIRE

    Trajković, Dušan; Jordeva, Sonja; Tomovska, Elena; Zafirova, Koleta

    2017-01-01

    Polyester waste is the dominant component of the clothing industry waste stream, yet its recycling in this industry is rarely addressed. This paper proposes using polyester cutting waste as an insulation blanket for roofing and buildings’ internal walls in order to reduce environmental pollution. The designed textile structures used waste cuttings from different polyester fabrics without opening the fabric to fibre. Thermal insulation, acoustic insulation, fire resistance and biodegradation o...

  13. 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: ...

  14. 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.

  15. High Temperature Electrical Insulation Materials for Space Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's future space science missions cannot be realized without the state of the art high temperature insulation materials of which higher working temperature, high...

  16. Light fireproof insulating plate-formed material

    Energy Technology Data Exchange (ETDEWEB)

    Plum, B.A.; Juhl, L.F.

    1981-02-23

    Light fireproof insulating plates were produced by pressure processing of a mixture of rice-husk ashes with pearlite aluminium phosphate and glass wool. The corn size of pearlite is 0-5 mm., of rice-husk ashes 0-5 mm. and the fiber length of fibrous additive is about 25 mm.

  17. PRODUCTION OF AN INSULATION MATERIAL FROM CARPET AND BORON WASTES

    OpenAIRE

    Yasin ERDOĞAN

    2016-01-01

    Buildings are large consumers of energy in all countries. In regions with harsh climatic conditions, a substantial share of energy goes to heat and cool buildings. This paper reports an investigation of the insulation materials made from mixing carpet wastes with a solution with added crude colemanite ore, one of boron minerals, and a solution with added colemanite wastes from a barrage. A new building insulation material was produced which is name, Halibor. Optimum mixing ratios were determi...

  18. Insulating materials from renewable raw materials. 4. ed.; Daemmstoffe aus nachwachsenden Rohstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Brandhorst, Joerg; Spritzendorfer, Josef; Gildhorn, Kai; Hemp, Markus

    2012-03-27

    The thermal insulation has become a central issue in the construction and renovation of buildings. The question of healthy building materials and appropriate construction follows the desire of a comfartable and allergy-free living. Due to these developments, insulation materials from renewable resources increasingly has raised the consciousness. The brochure under consideration describes the dynamic market of insulation materials consisting of renewable raw materials. Wood fibers, wood wool, sheep wool, flax, hemp, reeds, meadow grass, cork, cellulose, seaweed and bulrushes are considered as renewable raw materials for insulating materials.

  19. Growing and testing mycelium bricks as building insulation materials

    Science.gov (United States)

    Xing, Yangang; Brewer, Matthew; El-Gharabawy, Hoda; Griffith, Gareth; Jones, Phil

    2018-02-01

    In order to improve energy performance of buildings, insulation materials (such as mineral glass and rock wools, or fossil fuel-based plastic foams) are being used in increasing quantities, which may lead to potential problem with materials depletions and landfill disposal. One sustainable solution suggested is the use of bio-based, biodegradable materials. A number of attempts have been made to develop biomaterials, such as sheep wood, hemcrete or recycled papers. In this paper, a novel type of bio insulation materials - mycelium is examined. The aim is to produce mycelium materials that could be used as insulations. The bio-based material was required to have properties that matched existing alternatives, such as expanded polystyrene, in terms of physical and mechanical characteristics but with an enhanced level of biodegradability. The testing data showed mycelium bricks exhibited good thermal performance. Future work is planned to improve growing process and thermal performance of the mycelium bricks.

  20. Data base of radiation-resistant dielectric and insulating materials

    International Nuclear Information System (INIS)

    Hama, Yoshimasa; Sunazuka, Hideo; Nashiyama, Isamu; Kakuta, Tsunemi.

    1987-01-01

    In the data base of radiation-resistant dielectric and insulating materials, the data format contains such items as to give the summary; the data sheet contains the data in concrete form of respective properties from the references; the sheet of references contains the references in the former two. In the above three, there are attached code No., data sheet No., reference No. and key words. In the three areas as radiation-resistant dielectric and insulating materials, i.e., organic materials, inorganic materials and optical fibers, the following are explained: data format, data sheet and objectives. (Mori, K.)

  1. Material-controlled dynamic vacuum insulation

    Science.gov (United States)

    Benson, D.K.; Potter, T.F.

    1996-10-08

    A compact vacuum insulation panel is described comprising a chamber enclosed by two sheets of metal, glass-like spaces disposed in the chamber between the sidewalls, and a high-grade vacuum in the chamber includes apparatus and methods for enabling and disabling, or turning ``on`` and ``off`` the thermal insulating capability of the panel. One type of enabling and disabling apparatus and method includes a metal hydride for releasing hydrogen gas into the chamber in response to heat, and a hydrogen grate between the metal hydride and the chamber for selectively preventing and allowing return of the hydrogen gas to the metal hydride. Another type of enabling and disabling apparatus and method includes a variable emissivity coating on the sheets of metal in which the emissivity is controllably variable by heat or electricity. Still another type of enabling and disabling apparatus and method includes metal-to-metal contact devices that can be actuated to establish or break metal-to-metal heat paths or thermal short circuits between the metal sidewalls. 25 figs.

  2. Water absorption and desorption in shuttle ablator and insulation materials

    Science.gov (United States)

    Whitaker, A. F.; Smith, C. F.; Wooden, V. A.; Cothren, B. E.; Gregory, H.

    1982-01-01

    Shuttle systems ablator and insulation materials underwent water soak with subsequent water desorption in vacuum. Water accumulation in these materials after a soak for 24 hours ranged from +1.1% for orbiter tile to +161% for solid rocket booster MSA-1. After 1 minute in vacuum, water retention ranged from none in the orbiter tile to +70% for solid rocket booster cork.

  3. PRODUCTION OF AN INSULATION MATERIAL FROM CARPET AND BORON WASTES

    Directory of Open Access Journals (Sweden)

    Yasin ERDOĞAN

    2016-12-01

    Full Text Available Buildings are large consumers of energy in all countries. In regions with harsh climatic conditions, a substantial share of energy goes to heat and cool buildings. This paper reports an investigation of the insulation materials made from mixing carpet wastes with a solution with added crude colemanite ore, one of boron minerals, and a solution with added colemanite wastes from a barrage. A new building insulation material was produced which is name, Halibor. Optimum mixing ratios were determined for mass production and the physical properties of the product were established. In addition, the material produced was compared with similar products used in buildings in terms of physical properties. As a result of the investigations, it was established that the product provides high heat and sound insulation and can be used easily in building and construction industry.

  4. Thermal highly porous insulation materials made of mineral raw materials

    Science.gov (United States)

    Mestnikov, A.

    2015-01-01

    The main objective of the study is to create insulating foam based on modified mineral binders with rapid hardening. The results of experimental studies of the composition and properties of insulating foam on the basis of rapidly hardening Portland cement (PC) and gypsum binder composite are presented in the article. The article proposes technological methods of production of insulating foamed concrete and its placement to the permanent shuttering wall enclosures in monolithic-frame construction and individual energy-efficient residential buildings, thus reducing foam shrinkage and improving crack-resistance.

  5. Topological insulators/superconductors: Potential future electronic materials

    International Nuclear Information System (INIS)

    Hor, Y. S.

    2014-01-01

    A new material called topological insulator has been discovered and becomes one of the fastest growing field in condensed matter physics. Topological insulator is a new quantum phase of matter which has Dirac-like conductivity on its surface, but bulk insulator through its interior. It is considered a challenging problem for the surface transport measurements because of dominant internal conductance due to imperfections of the existing crystals of topological insulators. By a proper method, the internal bulk conduction can be suppressed in a topological insulator, and permit the detection of the surface currents which is necessary for future fault-tolerant quantum computing applications. Doped topological insulators have depicted a large variety of bulk physical properties ranging from magnetic to superconducting behaviors. By chemical doping, a TI can change into a bulk superconductor. Nb x Bi 2 Se 3 is shown to be a superconductor with T c ∼ 3.2 K, which could be a potential candidate for a topological superconductor

  6. CERTIFICATION OF THE RADIATION RESISTANCE OF COIL INSULATION MATERIAL

    CERN Document Server

    Polinski, J; Bogdan, P

    2013-01-01

    The goal of the WP 7.2.1 sub-task of the EuCARD program has been to determine the Nb$_{3}$Sn based accelerator magnet coil electrical insulation resistance against irradiation, which will occur in future accelerators. The scope of the certification covers determination of mechanical, electrical and thermal properties changes due to irradiation. The report presents a selection of the insulation material candidates for future accelerator magnets as well as the definition of the radiation certification methodology with respect of radiation type, energy, doses and irradiation conditions. The test methods and results of the electrical and mechanical insulation materials properties degradation due to irradiation are presented. Thermal conductivity and Kapitza resistance at temperature range from 1.5 K to 2.0 K (superfluid helium conditions) are given.

  7. Simulation of energy- efficient building prototype using different insulating materials

    Science.gov (United States)

    Ouhaibi, Salma; Belouaggadia, Naoual; Lbibb, Rachid; Ezzine, Mohammed

    2018-05-01

    The objective of this work is to analyze the energetic efficiency of an individual building including an area of 130 m2 multi-zone, located in the region of FEZ which is characterized by a very hot and dry climate in summer and a quite cold one in winter, by incorporating insulating materials. This study was performed using TRNSYS V16 simulation software during a typical year of the FEZ region. Our simulation consists in developing a comparative study of two types of polystyrene and silica-aerogel insulation materials, in order to determine the best thermal performance. The results show that the thermal insulation of the building envelope is among the most effective solutions that give a significant reduction in energy requirements. Similarly, the use of silica-aerogels gives a good thermal performance, and therefore a good energy gain.

  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. Hydrogen interactions with silicon-on-insulator materials

    OpenAIRE

    Rivera de Mena, A.J.

    2003-01-01

    The booming of microelectronics in recent decades has been made possible by the excellent properties of the Si/SiO2 interface in oxide on silicon systems.. This semiconductor/insulator combination has proven to be of great value for the semiconductor industry. It has made it possible to continuously increase the number of transistors per chip until the physical limit of integration is now almost reached. Silicon-on-insulator (SOI) materials were early on seen as a step in the logical evolutio...

  10. 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.

  11. Investigation of Insulation Materials for Future Radioisotope Power Systems

    Science.gov (United States)

    Cornell, Peggy A.; Hurwitz, Frances I.; Ellis, David L.; Schmitz, Paul C.

    2013-01-01

    NASA's Radioisotope Power Systems (RPS) Technology Advancement Project is developing next generation high-temperature insulation materials that directly benefit thermal management and improve performance of RPS for future science missions. Preliminary studies on the use of multilayer insulation (MLI) for Stirling convertors used on the Advanced Stirling Radioisotope Generator (ASRG) have shown the potential benefits of MLI for space vacuum applications in reducing generator size and increasing specific power (W/kg) as compared to the baseline Microtherm HT (Microtherm, Inc.) insulation. Further studies are currently being conducted at NASA Glenn Research Center on candidate MLI foils and aerogel composite spacers. This paper presents the method of testing of foils and spacers and experimental results to date.

  12. Investigation of Insulation Materials for Future Radioisotope Power Systems (RPS)

    Science.gov (United States)

    Cornell, Peggy A.; Hurwitz, Frances I.; Ellis, David L.; Schmitz, Paul C.

    2013-01-01

    NASA's Radioisotope Power System (RPS) Technology Advancement Project is developing next generation high temperature insulation materials that directly benefit thermal management and improve performance of RPS for future science missions. Preliminary studies on the use of multilayer insulation (MLI) for Stirling convertors used on the Advanced Stirling Radioisotope Generator (ASRG) have shown the potential benefits of MLI for space vacuum applications in reducing generator size and increasing specific power (W/kg) as compared to the baseline Microtherm HT (Microtherm, Inc.) insulation. Further studies are currently being conducted at NASA Glenn Research Center (GRC) on candidate MLI foils and aerogel composite spacers. This paper presents the method of testing of foils and spacers and experimental results to date.

  13. Transport and screen blockage characteristics of reflective metallic insulation materials

    International Nuclear Information System (INIS)

    Brocard, D.N.

    1984-01-01

    In the event of a LOCA within a nuclear power plant, it is possible for insulation debris to be generated by the break jet. Such debris has the potential for PWR sump screen (or BWR RHR suction inlet) blockage and thus can affect the long-term recirculation capability. In addition to the variables of break jet location and orientation, the types and quantities of debris which could be generated are dependent on the insulation materials employed. This experimental investigation was limited to reflective metallic insulation and components thereof. The study was aimed at determining the flow velocities needed to transport the insulation debris to the sump screens and the resulting modes of screen blockage. The tests revealed that thin metallic foils (0.0025 in. and 0.004 in.) could transport at low flow velocities, 0.2 to 0.5 ft/sec. Thicker foils (0.008 in.) transported at higher velocities, 0.4 to 0.8 ft/sec, and as fabricated half cylinder insulation units required velocities in excess of 1.0 ft/sec for transport. The tests also provided information on screen blockage patterns that showed blockage could occur at the lower portion of the screen as foils readily flipped on the screen when reaching it

  14. Investigation of the Hygrothermal Performance of Alternative Insulation Materials

    DEFF Research Database (Denmark)

    Rode, Carsten; Kristiansen, Finn Harken; Rasmussen, Niels T.

    1999-01-01

    The paper gives an account of hygrothermal investigations carried out on some insulation products which are "alternative" to the ones that are traditionally used in Danish constructions. The alternative products are claimed to be friendly both to the environment and to the labour force. The mater......The paper gives an account of hygrothermal investigations carried out on some insulation products which are "alternative" to the ones that are traditionally used in Danish constructions. The alternative products are claimed to be friendly both to the environment and to the labour force...... is determined for the different materials with a guarded hot plate apparatus in which different vapour pressure conditions can be maintained over the specimens. The apparatus and some results are presented.2. Computational analysis of the hygrothermal performance of constructions with alternative insulation...... products.The hygrothermal performance of constructions with alternative insulation products is analysed with a computational model for combined heat and moisture transfer. The analysis concerns both traditional wall and roof constructions with the alternative insulation products, and some alternative...

  15. Insulating materials from renewable raw materials. 3. upd. ed.; Daemmstoffe aus nachwachsenden Rohstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Brandhorst, Joerg; Spritzendorfer, Josef; Gildhorn, Kai; Hemp, Markus

    2009-07-01

    Due to increasing energy prices, obligations to climatic protection and the desire for comfortable, allergy-free living, the thermal insulation is a central question with building and sanitation. Under this aspect, the contribution under consideration describes the very dynamic market of the insulating materials from renewable raw materials and deals with the questions of the users. In particular, the following raw materials are considered in the production of insulating materials: Wood fibre, wood chips, wood wool, sheep wool, flax, hemp, reeds, straw, cellulose.

  16. Insulating materials for cables: state of the technology and future developments

    Energy Technology Data Exchange (ETDEWEB)

    Blechschmidt, H H [Hessische Elektrizitaets-A.G., Darmstadt (Germany, F.R.)

    1977-02-01

    This article gives a summary of old and new insulating materials for electrical cables. The electrical properties of some polymer insulating materials (PVC, polyethelene (PE), polymerised polyethelene (VPE), polypropylene) are compared in a table with the properties of paper insulation. The changeover from oiled paper to plastic insulation is almost complete for low voltage cables. Soft PVC is the dominant insulating material in this field. For medium voltage cables (10 kV and 20 kV supplies) and for high voltage cables (60 kV and 110 kV supplies) there is a trend to plastic PE/VPE, because these insulating materials have better electrical properties than PVC.

  17. Development of flame retardant, radiation resistant insulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, M.

    1984-01-01

    On the cables used for nuclear power stations, in particular those ranked as IE class, flame retardation test, simulated LOCA environment test, radiation resistance test and so on are imposed. The results of the evaluation of performance by these tests largely depend on the insulating materials mainly made of polymers. Ethylene propylene copolymer rubber has been widely used as cable insulator because of its electrical characteristics, workability, economy and relatively good radiation resistance, but it is combustible, therefore, in the practical use, it is necessary to make it fire resistant. The author et al. have advanced the research on the molecular design of new fire retarding materials, and successfully developed acenaphthylene bromide condensate, which is not only fire resistant but also effective for improving radiation resistance. The condition of flame retardant, radiation resistant auxiliary agents is explained, and there are additive type and reaction type in fire retarding materials. The synthesis of acenaphthylene bromide condensate and its effect of giving flame retardant and radiation resistant properties are reported. The characteristics of the cables insulated with the flame retardant ethylene propylene rubber containing acenaphthylene bromide condensate were tested, and the results are shown. (Kako, I.).

  18. Compilation of radiation damage test data cable insulating materials

    CERN Document Server

    Schönbacher, H; CERN. Geneva

    1979-01-01

    This report summarizes radiation damage test data on commercially available organic cable insulation and jacket materials: ethylene- propylene rubber, Hypalon, neoprene rubber, polyethylene, polyurethane, polyvinylchloride, silicone rubber, etc. The materials have been irradiated in a nuclear reactor to integrated absorbed doses from 5*10/sup 5/ to 5*10/sup 6/ Gy. Mechanical properties, e.g. tensile strength, elongation at break, and hardness, have been tested on irradiated and non-irradiated samples. The results are presented in the form of tables and graphs, to show the effect of the absorbed dose on the measured properties. (13 refs).

  19. Nanometric holograms based on a topological insulator material.

    Science.gov (United States)

    Yue, Zengji; Xue, Gaolei; Liu, Juan; Wang, Yongtian; Gu, Min

    2017-05-18

    Holography has extremely extensive applications in conventional optical instruments spanning optical microscopy and imaging, three-dimensional displays and metrology. To integrate holography with modern low-dimensional electronic devices, holograms need to be thinned to a nanometric scale. However, to keep a pronounced phase shift modulation, the thickness of holograms has been generally limited to the optical wavelength scale, which hinders their integration with ultrathin electronic devices. Here, we break this limit and achieve 60 nm holograms using a topological insulator material. We discover that nanometric topological insulator thin films act as an intrinsic optical resonant cavity due to the unequal refractive indices in their metallic surfaces and bulk. The resonant cavity leads to enhancement of phase shifts and thus the holographic imaging. Our work paves a way towards integrating holography with flat electronic devices for optical imaging, data storage and information security.

  20. 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.

  1. Verification of the behavior of insulating materials under ionizing radiation

    International Nuclear Information System (INIS)

    Reis, Joao C. Marques dos; Rezende, Aurimar de P.; Menzel, Silvio C.

    2009-01-01

    To analyze the behavior of specifics electrical insulating materials and components under ionizing radiation, a test program was developed to verify the overall effects of general electrical equipment under high radiation fields conditions. The main objective is for maintenance purposes, in the substitution of electrical components installed in the reactor building of the Angra 1 nuclear power plant. Knowing the characteristics of electrical insulating materials available in the country and determining by tests their ability to withstand the ionizing radiation effects, is feasible to implement specific maintenance services of electrical equipment, maintaining the same level of quality and safety for the specified application. This procedure reduces the time and also costs of maintenance services, in comparison with materials acquired or services performed abroad. The isolating materials and components of electrical equipment should be specified, manufactured and qualified to withstand aggressive environmental conditions in the reactor building during the normal operation and postulated accident. Additional tests should be conducted to verify the conditions of the aged material by ionizing radiation. Examples of additional tests: dielectric strength, tensile strength and elongation and impact resistance. (author)

  2. Methodology for Evaluating Raw Material Changes to RSRM Elastomeric Insulation Materials

    Science.gov (United States)

    Mildenhall, Scott D.; McCool, Alex (Technical Monitor)

    2001-01-01

    The Reusable Solid Rocket Motor (RSRM) uses asbestos and silicon dioxide filled acrylonitrile butadiene rubber (AS-NBR) as the primary internal insulation to protect the case from heat. During the course of the RSRM Program, several changes have been made to the raw materials and processing of the AS-NBR elastomeric insulation material. These changes have been primarily caused by raw materials becoming obsolete. In addition, some process changes have been implemented that were deemed necessary to improve the quality and consistency of the AS-NBR insulation material. Each change has been evaluated using unique test efforts customized to determine the potential impacts of the specific raw material or process change. Following the evaluations, the various raw material and process changes were successfully implemented with no detectable effect on the performance of the AS-NBR insulation. This paper will discuss some of the raw material and process changes evaluated, the methodology used in designing the unique test plans, and the general evaluation results. A summary of the change history of RSRM AS-NBR internal insulation is also presented.

  3. Fatigue effects in insulation materials for fusion magnets

    International Nuclear Information System (INIS)

    Rosenkranz, P.

    2000-12-01

    The mechanical properties of insulation materials for the superconducting magnets of ITER (International Thermonuclear Experimental Reactor) and future fusion plants, i.e. woven fiber reinforced composites, have been identified as an area of concern for the long-term operation of such magnets. The magnets will be subjected to fast neutron and γ-radiation over their lifetime, which influence the mechanical properties of the insulation materials. The ultimate tensile strength and, above all, the interlaminar shear strength and their performance under dynamic load, corresponding to the pulsed operation of a TOKAMAK-confinement system, are sensitive indicators of material failure in fiber-reinforced laminates especially at cryogenic temperatures. To simulate these conditions, low frequency fatigue measurements at 10 Hz were made at 77 K up to one million cycles. Tension-tension fatigue tests were performed according to ASTM D3479. However, due to the space limitations in all irradiation facilities, the tests have to be done on samples, which are considerably smaller than those required for standard test conditions. The influence of the specimen geometry on the ultimate tensile strength under static and dynamic load conditions was, therefore, investigated on fiber-reinforced plastics. They did not show any systematic trends as long as the sample thickness does not exceed the thickness recommended in ASTM D3479. The double lap shear test method was chosen for the shear experiments because of the symmetry of the specimen geometry under tensile load and the suitability for fatigue tests. Like almost every existing test procedure for the interlaminar shear strength, this test method does not provide for a completely uniform interlaminar shear stress distribution over a sizable region in the test section of the specimen. A scaling program combined with FE-simulations was, therefore, initiated to assess the influence of the length of the test section and of the sample

  4. Adsorption on insulator materials enhanced by D implantation

    International Nuclear Information System (INIS)

    Ibarra, A.; Climent-Font, A.; Munoz-Martin, A.

    2005-01-01

    Many insulator materials used in ITER are exposed to a gas phase composed of D, T and a plasma with hydrocarbons, Fe and other particles combined with the presence of an intense neutron and gamma radiation field. Some of these materials (Al 2 O 3 and SiO 2 ) are implanted at room temperature with low energy D and H ions in order to simulate some of the DT gas effects. The implantation is characterized using optical absorption and elastic recoil detection analysis (ERDA) techniques. It is observed that ion implantation as well as electron or gamma irradiation increases the surface scattering and the concentration of C and H adsorbed at the surface, suggesting that a radiation-induced surface degradation process is taking place and an increase of the surface adsorption capability. The effect is higher for higher dose implantation and for lower energy

  5. 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...

  6. Assessment of fibrous insulation materials for the selenide isotope generator system

    International Nuclear Information System (INIS)

    Wei, G.C; Tennery, V.J.

    1977-11-01

    Fibrous insulations for use in the converter and the heat source of the radioisotope-powered, selenide element, thermoelectric generator (selenide isotope generator) are assessed. The most recent system design and material selection basis is presented. Several fibrous insulation materials which have the potential for use as load-bearing or nonload-bearing thermal insulations are reviewed, and thermophysical properties supplied by manufacturers or published in the literature are presented. Potential problems with the application of fibrous insulations in the selenide isotope generator are as follows: compatibility with graphite, the thermoelectric elements, and the isolation hot frame; devitrification, grain growth, and sintering with an accompanying degradation of insulation quality; impurity diffusion from the insulation to adjoining structures; outgassing and storage of fibrous materials. Areas in which thermophysical data or quantitative information on the insulation and structural stability is lacking are identified

  7. Competitive landscape of the EU’s insulation materials industry for energy-efficient buildings

    OpenAIRE

    PAVEL CLAUDIU; BLAGOEVA DARINA

    2017-01-01

    Insulation materials could contribute significantly to improving the overall energy efficiency and sustainability of the buildings, especially by reducing the energy losses through the building envelope (walls, roofs, floors, etc.). The global demand for thermal insulation materials in building applications is projected to increase at a CAGR of 4.5 % between 2016 and 2027. In the EU the demand for thermal insulation materials is estimated at 3.48 % (2015-2027). Wool minerals (glass and stone ...

  8. Basalt fiber insulating material with a mineral binding agent for industrial use

    Science.gov (United States)

    Drozdyuk, T.; Aizenshtadt, A.; Tutygin, A.; Frolova, M.

    2016-04-01

    The paper considers a possibility of using mining industry waste as a binding agent for heat insulating material on the basis of basalt fiber. The main objective of the research is to produce a heat-insulating material to be applied in machine building in high-temperature environments. After synthetic binder having been replaced by a mineral one, an environmentally sound thermal insulating material having desirable heat-protecting ability and not failing when exposed to high temperatures was obtained.

  9. Effect of radiation resistance additives for insulation materials

    International Nuclear Information System (INIS)

    Yamamoto, Yasuaki; Yagyu, Hideki; Seguchi, Tadao.

    1988-01-01

    For the electric wires and cables used in radiation environment such as nuclear power stations and fuel reprocessing facilities, the properties of excellent radiation resistance are required. For these insulators and sheath materials, ethylene propylene rubber, polyethylene and other polymers have been used, but it cannot be said that they always have good radiation resistance. However, it has been well known that radiation resistance can be improved with small amount of additives, and heat resistance and burning retarding property as well as radiation resistance are given to the insulators of wires and cables for nuclear facilities by mixing various additives. In this research, the measuring method for quantitatively determining the effect of Anti-rad (radiation resistant additive) was examined. Through the measurement of gel fraction, radical formation and decomposed gas generation, the effect of Anti-rad protecting polymers from radiation deterioration was examined from the viewpoint of chemical reaction. The experimental method and the results are reported. The radiation energy for cutting C-H coupling is polymers is dispersed by Anti-rad, and the probability of cutting is lowered. Anti-rad catches and extinguishes radicals that start oxidation reaction. (K.I.)

  10. Electric breakdown of high polymer insulating materials at cryogenic temperature

    International Nuclear Information System (INIS)

    Kim, Sanhyon; Yoshino, Katsumi

    1985-01-01

    Cryogenic properties : temperature dependence of E sub(b) and effects of media upon E sub(b) were investigated on several high polymers. Temperature conditions were provided by liquid He (4.2 K), liquid N 2 (77 K) and cryogen (dry ice-methyl alcohol, 194 K). Silicone oil was used also at ambient temperature and elevated temperature. Polymer film coated with gold by vacuum evaporation was placed in cryostat, and high tension from pulse generator was applied to the film. Dielectric breakdowns were detected by oscilloscope and observed visually. The results of experiment are summerized as follow. (1) E sub(b) of film in He is affected by medium remarkably, and covering with 3-methyl pentane is effective for increasing E sub(b). (2) Temperature dependence of E sub(b) was not recognized in cryogenic temperature below liquid N 2 . (3) Temperature characteristic of E sub(b) changes considerably at the critical temperature T sub(c), and T sub(c) is dependent on material. (4) Strength against dielectric breakdown under cryogenic temperature is not affected by bridging caused by irradiation of electron beam. (5) Dielectric breakdown is thought to be caused by electronic process such as electron avalanche. Consequently, for designing insulation for the temperature below liquid He, insulation design for liquid N 2 is thought to be sufficient. However, the degradation and breakdown by mechanical stress under cryogenic temperature must be taken into consideration. (Ishimitsu, A.)

  11. Organic Insulation Materials, the Effect on Indoor Humidity, and the Necessity of a Vapor Barrier

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Examples of organic insulation products are cellulose fiber, other plant fiber, and animal wool. These materials, which are all very hygroscopic, are associated with certain assertions about their building physical behavior that need to be verified.Examples of such assertions are: "A vapor barrier...... is not needed when using organic insulation materials" and "Organic insulation materials have a stabilizing effect on the indoor humidity".The paper presents some numerical analyses of the hygrothermal behavior of wall constructions and the occupied spaces they surround when an organic insulation material...

  12. INSUL, Calculation of Thermal Insulation of Various Materials Immersed in He

    International Nuclear Information System (INIS)

    Kinkead, A.N.; Pitchford, B.E.

    1977-01-01

    1 - Nature of the physical problem solved: Performance of thermal insulation immersed in helium. 2 - Method of solution: Mineral fibre, metal fibre and metallic multi-layer foils are studied. An approximate analysis for performance evaluation of multi-layer insulation in vertical gas spaces including the regime between fully suppressed natural convection and that for which an accepted power relationship applies is included

  13. Acoustic parameters of sound insulating materials investigation in small reverberation rooms on rubber plates

    Directory of Open Access Journals (Sweden)

    О.О. Козлітін

    2005-01-01

    Full Text Available  The new method of sound insulating materials acoustic characteristics investigation in small reverberation rooms was elaborated. The research of sound insulating materials on rubber plates was done. The analysis of obtained results of acoustic parameters of materials being a part of the composite real structures of airplane was carried out.

  14. A protocol for lifetime energy and environmental impact assessment of building insulation materials

    International Nuclear Information System (INIS)

    Shrestha, Som S.; Biswas, Kaushik; Desjarlais, Andre O.

    2014-01-01

    This article describes a proposed protocol that is intended to provide a comprehensive list of factors to be considered in evaluating the direct and indirect environmental impacts of building insulation materials, as well as detailed descriptions of standardized calculation methodologies to determine those impacts. The energy and environmental impacts of insulation materials can generally be divided into two categories: (1) direct impact due to the embodied energy of the insulation materials and other factors and (2) indirect or environmental impacts avoided as a result of reduced building energy use due to addition of insulation. Standards and product category rules exist, which provide guidelines about the life cycle assessment (LCA) of materials, including building insulation products. However, critical reviews have suggested that these standards fail to provide complete guidance to LCA studies and suffer from ambiguities regarding the determination of the environmental impacts of building insulation and other products. The focus of the assessment protocol described here is to identify all factors that contribute to the total energy and environmental impacts of different building insulation products and, more importantly, provide standardized determination methods that will allow comparison of different insulation material types. Further, the intent is not to replace current LCA standards but to provide a well-defined, easy-to-use comparison method for insulation materials using existing LCA guidelines. - Highlights: • We proposed a protocol to evaluate the environmental impacts of insulation materials. • The protocol considers all life cycle stages of an insulation material. • Both the direct environmental impacts and the indirect impacts are defined. • Standardized calculation methods for the ‘avoided operational energy’ is defined. • Standardized calculation methods for the ‘avoided environmental impact’ is defined

  15. 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...

  16. Converters and electric machines. Solid insulating materials. Electrical characteristics; Convertisseurs et machines electriques. Materiaux isolants solides. Caracteristiques electriques

    Energy Technology Data Exchange (ETDEWEB)

    Anton, A. [Institut National Superieur de Chimie Industrielle, 76 - Rouen (France)

    2003-08-01

    The aim of this article is to allow a preselection of a solid insulating material using the most common electrical characteristics: tangent of the loss angle, relative permittivity, dielectric rigidity, superficial resistivity, transverse resistivity, resistance to high voltage creeping spark currents, index of creeping resistance. The characteristics of the main solid insulating materials are presented in tables for: thermoplastics, thermosetting materials, natural insulating materials, mineral insulating materials, rubber and synthetic elastomers, stratified insulating materials, thermoplastic films, composite synthetic papers. A comparison is made between the different materials using the three properties: tangent of the loss angle, relative permittivity and resistance to HV spark creeping currents. (J.S.)

  17. Influence of Wind Speed on Heat Flow through Polypropylene Insulating Material

    Institute of Scientific and Technical Information of China (English)

    SUN Yu-chai; CHENG Zhong-hao; FENG Xun-wei

    2006-01-01

    The heat transfer properties of polypropylene insulation at different ambient temperature against wind were analysed.A theoretical model of the combined conductive, convective and radiative heat flow through fibrous insulating material was presented. Detail study was carried out by using the finite element method. The theoretical results are in accordance to the experimental results which were accomplished in an artificial climate chamber.

  18. State of the art on historic building insulation materials and retrofit strategies

    DEFF Research Database (Denmark)

    Blumberga, Andra; Kass, Kristaps; Kamendere, Edite

    2016-01-01

    This report provides an analysis and evaluation of a state-of-the-art of internal insulation materials and methods for application in historic buildings, and review on methods, tools and guidelines used as decision making tools for implementation of internal insulation in historic buildings. Hist...

  19. FOREWORD International Conference on Defects in Insulating Materials

    Science.gov (United States)

    Valerio, Mário Ernesto Giroldo; Jackson, R. A.

    2010-11-01

    These proceedings represent a sample of the scientific works presented during ICDIM2008, the 16th International Conference on Defects in Insulating Materials, held at the Federal University of Sergipe, Aracaju, Brazil from 24-29 August 2008. The conference was the latest in a series which began at Argonne in 1956, and which has been held most recently in Riga, Latvia (2004) and Johannesburg, South Africa (2000). The conference was also related scientifically to the EURODIM series, which have been held most recently in Milan, Italy (2006), Wroclaw, Poland (2002) and Pecs, Hungary (2010). The aim of the conference was to bring together physicists, chemists and materials scientist to discuss defects in insulating materials and their effect on materials, including their optical, mass/charge transport, energy storage and sensor properties. The conference featured 6 plenary lectures, 60 contributed lectures and about 130 posters. The posters were displayed for the whole conference, but discussed in two three-hour sessions. We are grateful to the International Advisory Committee for suggesting invited speakers and to the Programme Committee for their help in refereeing all the abstracts and choosing the contributed oral contributions. We would also like to thank the Local Organising Committee and the Brazilian Physical Society for their help with local organisation and the online registration/payment process respectively. The chairpersons would like to specially thanks all the sponsors listed below for financial support. The Federal University of Sergipe, one of the public and 'free tuition' Universities of the Country, run by the Brazilian Ministry of Education, were pleased to host this 16th meeting, the first one in Latin America. Mario E G Valerio Conference Chair Robert A Jackson Programme Chair Conference Scope Scope of the Conference was the presentation of the latest investigations on point and extended defects in bulk materials and thin films. Technological

  20. 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.

  1. Irradiation effect of the insulating materials for fusion superconducting magnets at cryogenic temperature

    Science.gov (United States)

    Kobayashi, Koji; Akiyama, Yoko; Nishijima, Shigehiro

    2017-09-01

    In ITER, superconducting magnets should be used in such severe environment as high fluence of fast neutron, cryogenic temperature and large electromagnetic forces. Insulating material is one of the most sensitive component to radiation. So radiation resistance on mechanical properties at cryogenic temperature are required for insulating material. The purpose of this study is to evaluate irradiation effect of insulating material at cryogenic temperature by gamma-ray irradiation. Firstly, glass fiber reinforced plastic (GFRP) and hybrid composite were prepared. After irradiation at room temperature (RT) or liquid nitrogen temperature (LNT, 77 K), interlaminar shear strength (ILSS) and glass-transition temperature (Tg) measurement were conducted. It was shown that insulating materials irradiated at room temperature were much degraded than those at cryogenic temperature.

  2. Recent Advances in the Sound Insulation Properties of Bio-based Materials

    Directory of Open Access Journals (Sweden)

    Xiaodong Zhu

    2013-12-01

    Full Text Available Many bio-based materials, which have lower environmental impact than traditional synthetic materials, show good sound absorbing and sound insulation performances. This review highlights progress in sound transmission properties of bio-based materials and provides a comprehensive account of various multiporous bio-based materials and multilayered structures used in sound absorption and insulation products. Furthermore, principal models of sound transmission are discussed in order to aid in an understanding of sound transmission properties of bio-based materials. In addition, the review presents discussions on the composite structure optimization and future research in using co-extruded wood plastic composite for sound insulation control. This review contributes to the body of knowledge on the sound transmission properties of bio-based materials, provides a better understanding of the models of some multiporous bio-based materials and multilayered structures, and contributes to the wider adoption of bio-based materials as sound absorbers.

  3. Hydrogen interactions with silicon-on-insulator materials

    NARCIS (Netherlands)

    Rivera de Mena, A.J.

    2003-01-01

    The booming of microelectronics in recent decades has been made possible by the excellent properties of the Si/SiO2 interface in oxide on silicon systems.. This semiconductor/insulator combination has proven to be of great value for the semiconductor industry. It has made it possible to continuously

  4. Safety distance for preventing hot particle ignition of building insulation materials

    OpenAIRE

    Jiayun Song; Supan Wang; Haixiang Chen

    2014-01-01

    Trajectories of flying hot particles were predicted in this work, and the temperatures during the movement were also calculated. Once the particle temperature decreased to the critical temperature for a hot particle to ignite building insulation materials, which was predicted by hot-spot ignition theory, the distance particle traveled was determined as the minimum safety distance for preventing the ignition of building insulation materials by hot particles. The results showed that for sphere ...

  5. Research on insulating material affecting the property of gas ionization chamber

    International Nuclear Information System (INIS)

    Wang Liqiang; Wang Zhentao; Zheng Jian

    2014-01-01

    The insulating material in ionization chamber affects the internal gas pressure and ionic pulse shape in the research process of the ion drift velocity in high pressure gas ionization chamber. It will affect the ion drift velocity measurement. It is required to isolate by insulating material between electrode to electrode and between electrodes to the shell of gas ionization chamber. Insulating material in gas ionization chamber is indispensable. Therefore it needs to carefully study the insulating material affecting the performance of gas ionization chamber. First of all, it is found that Teflon can slowly adsorb the working gas in ionization chamber, and the gas pressure in it is reduced when we measure the sensitivity of gas ionization chamber over time. It is verified by experiment that insulating materials absorbing and releasing gas is dynamically reversible process. Then the adsorbing gas property of 95% aluminium oxide ceramic and Teflon is studied through experimental comparision. Gas adsorption equilibrium time of ceramic material is faster, generally it is about a few hours, and the gas adsorption capacity is relatively less. Gas adsorption equilibrium time of Teflon is slower, it is about a few days, and the gas adsorption capacity is relatively more. It is found that Teflon will release part of the gas at higher temperature through experimental research on the influence of Teflon adsorbing gas. Finally it is studied that the distribution of insulation in ionization chamber affects the time response speed of ionization chamber by measuring the signal pulse shape of ionization chamber under the pulse X-ray. Through these experimental research, it is presented that it need to pay attention to select insulation material and to design the internal structure and arrangement of insulating material when we design gas ionization chamber. (authors)

  6. Investigation of deterioration mechanism of electrical ceramic insulating materials under high temperature

    International Nuclear Information System (INIS)

    Mizutani, Yoshinobu; Ito, Tetsuo; Okamoto, Tatsuki; Kumazawa, Ryoji; Aizawa, Rie; Moriyama, Hideshige

    2000-01-01

    It is thought that ceramic insulator can be applied to electric power equipments that are under high temperature not to be able use organic materials. Our research has suggested components of mica-alumina combined insulation. As the results of and carried out temperature accelerating test, combined insulation life is expected long term over 40 years at over 500-Celsius degrees. However to construct high reliable insulating system, it is clarified deterioration mechanism on combined insulation and evaluates life of that. Therefore we carried out metal behavior test and voltage aging test using mica-sheet and alumina-cloth that are components of combined insulation under high temperature in nitrogen gas atmosphere. It is cleared two metal behavior mechanisms: One is that the opening of insulator are filled up with copper that is oxidized, the other is the metal diffuses in alumina-cloth through surface. And distance of metal behavior is able to be estimated at modulate temperature and in modulate time. It is also cleared that alumina-cloth is deteriorated by metal behavior into alumina-cloth. These results indicate that combined insulation is deteriorated from electrode side by metal behavior and is finally broken down through alumina-cloth. (author)

  7. A Difference in Using Atomic Layer Deposition or Physical Vapour Deposition TiN as Electrode Material in Metal-Insulator-Metal and Metal-Insulator-Silicon Capacitors

    NARCIS (Netherlands)

    Groenland, A.W.; Wolters, Robertus A.M.; Kovalgin, Alexeij Y.; Schmitz, Jurriaan

    2011-01-01

    In this work, metal-insulator-metal (MIM) and metal-insulator-silicon (MIS) capacitors are studied using titanium nitride (TiN) as the electrode material. The effect of structural defects on the electrical properties on MIS and MIM capacitors is studied for various electrode configurations. In the

  8. Sound absorption of low-temperature reusable surface insulation candidate materials

    Science.gov (United States)

    Johnston, J. D.

    1974-01-01

    Sound absorption data from tests of four candidate low-temperature reusable surface insulation materials are presented. Limitations on the use of the data are discussed, conclusions concerning the effective absorption of the materials are drawn, and the relative significance to Vibration and Acoustic Test Facility test planning of the absorption of each material is assessed.

  9. Teaching Acoustic Properties of Materials in Secondary School: Testing Sound Insulators

    Science.gov (United States)

    Hernandez, M. I.; Couso, D.; Pinto, R.

    2011-01-01

    Teaching the acoustic properties of materials is a good way to teach physics concepts, extending them into the technological arena related to materials science. This article describes an innovative approach for teaching sound and acoustics in combination with sound insulating materials in secondary school (15-16-year-old students). Concerning the…

  10. Cardboard Based Packaging Materials as Renewable Thermal Insulation of Buildings: Thermal and Life Cycle Performance

    OpenAIRE

    Čekon, Miroslav; Struhala, Karel; Slávik, Richard

    2017-01-01

    Cardboard based packaging components represent a material with a significant potential of renewable exploitation in buildings. This study presents the results of thermal and environmental analysis of existing packaging materials compared with standard conventional thermal insulations. Experimental measurements were performed to identify the thermal performance of studied cardboard packaging materials. Real-size samples were experimentally tested in laboratory measurements. The thermal resi...

  11. Material science experience gained from the space nuclear rocket program: Insulators

    International Nuclear Information System (INIS)

    Wagner, P.

    1992-07-01

    Although Rover reactors are viewed as the ultimate in high-temperature operating systems, many of the materials used in these reactors (for example, support rods, control drums, and the reflector) have to be held at relatively low temperatures while the reactor operates, in order to maintain their structural integrity. Thus the insulators needed to separate these temperature domains are crucial to the reactor's ultimate operating times and temperatures. All of the reactors that were tested used pyrolytic graphite as the primary insulator. However, it had been long planned to replace the graphite with zirconium carbide and a lengthy and intensive effort to develop the zirconium carbide insulators had been made at the time Rover was terminated. This report details research and development and the experience we gained with both these insulator materials

  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. Nonlinear processes of magnons in insulating ferromagnetic materials

    International Nuclear Information System (INIS)

    Araujo, C.B. de.

    1975-04-01

    The representation of coherent states is used to investigate the excitation of magnons by 'parallel pumping', 'perpendicular pumping' and 'phonon pumping'. The stationary regime of the processes is studied with respect to the magnon population and the statistic behavior of the system below and just above the threshold. Particular attention is given to the thermodynamic and the coherence properties of the parametric states. The results show that just above the threshold the generated states become coherent. Also, it is shown that the non-linear processes have characteristics of a second-order phase transition with the pumping power as the 'reservoir variable' and the transverse dynamical magnetization as the 'order parameter'. Finally, the possibilities to extend the theory, its experimental check, and its convenience to study the other nonlinear processes of magnons and phonons in magnetic insulators are discussed. (author) [pt

  14. Materials Characterization and Microelectronic Implementation of Metal-insulator Transition Materials and Phase Change Materials

    Science.gov (United States)

    2015-03-26

    materials like crystalline semiconductors, graphene , and composites, the materials discussed here could have a significant impact. This thesis investigates...diagnosis [124], crystallinity of pharmaceutical materials [125], materials diagnosis for restoration of paintings [126], and materials research [127...temperature dots and paint were placed on samples on the substrate. Temperature dots are typically used in the transportation of goods such as food in order

  15. 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.

  16. 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.

  17. Opportunities in chemistry and materials science for topological insulators and their nanostructures

    KAUST Repository

    Kong, Desheng

    2011-10-24

    Electrical charges on the boundaries of topological insulators favour forward motion over back-scattering at impurities, producing low-dissipation, metallic states that exist up to room temperature in ambient conditions. These states have the promise to impact a broad range of applications from electronics to the production of energy, which is one reason why topological insulators have become the rising star in condensed-matter physics. There are many challenges in the processing of these exotic materials to use the metallic states in functional devices, and they present great opportunities for the chemistry and materials science research communities. © 2011 Macmillan Publishers Limited. All rights reserved.

  18. Effect that radiation exerts to insulation breakdown of heat resistant polymer materials

    International Nuclear Information System (INIS)

    Fujita, Shigetaka; Baba, Makoto; Noto, Fumitoshi; Ruike, Mitsuo.

    1990-01-01

    Artificial satellites are always exposed to cosmic rays which contain the radiations which do not reach the ground, therefore, the radiation resistance of the polymer insulators for cables and others used in such environment becomes a problem. Also the polymer insulator materials used for nuclear facilities require excellent radiation resistance. It is important to examine the effect that radiation exerts to electric insulation characteristics from the viewpoint of material development. In this paper, the insulation breakdown characteristics of heat resistant polymer films and the mini-cables made for trial of heat resistant polymer materials in the case without irradiation and in the case of gamma ray irradiation, and the results of the structural analysis are reported. The specimens tested, the experimental method and the results are described. The insulation breakdown strength of PFA and FEP films lowered from 0.15-0.2 MGy, but that of PEEK film did not change up to 5 MGy. It was found that fluorine group resins were apt to deteriorate by oxidation as dose increased. (K.I.)

  19. Effect on the insulation material of a MOSFET device submitted to a standard diagnostic radiation beam

    International Nuclear Information System (INIS)

    De Magalhaes, C M S; Dos Santos, L A P; Souza, D do N; Maia, A F

    2010-01-01

    MOSFET electronic devices have been used for dosimetry in radiology and radiotherapy. Several communications show that due to the radiation exposure defects appear on the semiconductor crystal lattice. Actually, the structure of a MOSFET consists of three materials: a semiconductor, a metal and an insulator between them. The MOSFET is a quadripolar device with a common terminal: gate-source is the input; drain-source is the output. The gate controls the electrical current passing through semiconductor medium by the field effect because the silicon oxide acts as insulating material. The proposal of this work is to show some radiation effects on the insulator of a MOSFET device. A 6430 Keithley sub-femtoamp SourceMeter was used to verify how the insulating material layer in the structure of the device varies with the radiation exposure. We have used the IEC 61267 standard radiation X-ray beams generated from a Pantak industrial unit in the radiation energy range of computed tomography. This range was chosen because we are using the MOSFET device as radiation detector for dosimetry in computed tomography. The results showed that the behaviour of the electrical current of the device is different in the insulator and semiconductor structures.

  20. Effect of oxygen in the simulated LOCA environments of the degradation of cable insulating materials

    International Nuclear Information System (INIS)

    Kusuma, Y.; Okada, S.; Itoh, M.; Yagi, T.; Yoshikawa, M.; Yoshida, K.; Machi, S.; Tamura, N.; Kawakami, W.

    1990-01-01

    Five kinds of insulating and jacketing materials for the cables used in nuclear power plants were exposed to various LOCA environments of both simultaneous and sequential methods using SEAMATE-II. Experimental conditions of the simultaneous LOCA tests were done at different radiation dose rate, steam temperature and amount of air added to the LOCA environments. The sequential tests consist of two stages, that is, pre-irradiation and subsequent steam/spray exposure. Pre-irradiation conditions and subsequent steam/spray exposure conditions of the sequential LOCA tests are systematically changed in order to find appropriate conditions which can bring about the degradation of same degree to those obtained for various simultaneous LOCA simulations. Tensile properties, insulating resistance and water sorption of the insulating materials exposed to various LOCA environments are measured and discussed. (author). 11 refs, 19 figs, 3 tabs

  1. Complex evaluation of properties for some thermal insulating materials of NPP

    International Nuclear Information System (INIS)

    Yurchenko, V.G.; Nazarova, G.A.; Yakunichev, V.N.; Potulov, V.V.; Kazakova, K.A.

    1991-01-01

    The effects of the main operational factors (temperature, ionizing radiation, increased humidity) on some most widely applied fibrous materials are investigated. The samples were irradiated by 60 Co gamma photons at the PKhM-gamma-20 device in air at temperature of 40±1 deg C in order to analyze the radiation resistance of thermal insulating materials. The analysis and generalization of the results of laboratory tests give an opportunity to make the following conclusions. The thermal insulation articles and constructions made of superfine basalt fiber may be used in the zones of rigorous regime. The superfine glass fibers (GF) are recommended to be used for equipment and pipeline shielding in the zones of rigorous control only as a part of multilayer insulation as the second or next layers and only in places where leaks are impossible

  2. Cooperative effect of radiation and vapor environments on the deterioration of insulator materials

    International Nuclear Information System (INIS)

    Kusama, Yasuo; Okada, Sohei; Yagi, Toshiaki; Ito, Masayuki; Yoshida, Kenzo; Tamura, Naoyuki

    1985-01-01

    Experimental results and speculations are described on the cooperative effect of radiation and vapor environments for the deterioration of insulator cable cladding materials such as polyethylene chlorosulphonate, ethylene propylene rubber, cross-linked polyethylene, chloroprene and silicone rubber, by the separate, simultaneous or subsequent exposure of the above-mentioned two kinds of exposure factors. These experiment was carried out by considering main environmental factors in the LOCA (loss of coolant accident) conditions. Radiation experiment was made by employing 60 Co source of 9.7 kGy/h at a room-temperature air condition. Vapor environment exposure was conducted by the conditions of 120 to 160 deg C steam-saturated air conditions and others. With the experimental results described on the characteristics of the five kinds of the above-mentioned insulator materials in radiation and saturated vapor conditions, the following conclusions were obtained. Acceleration of deterioration by the cooperative action of radiation and saturated vapor was found for the examined materials except the cross-linked polyethylene. In the subsequent exposure of radiation and saturated vapor, deterioration behavior was dependent on insulator materials and component ratios of the insulator materials. For the cross-linked polyethylene, annealing effect by heat was found, and the effect was less significent in the simultaneous exposure. Restoration phenomenon was found in the cross-linked polyethylene even in the saturated vapor exposure stage of the subsequent exposure conditions of radiation exposure followed by saturated vapor. (Takagi, S.)

  3. Application of Nanotechnology-Based Thermal Insulation Materials in Building Construction

    Directory of Open Access Journals (Sweden)

    Bozsaky David

    2016-03-01

    Full Text Available Nanotechnology-based materials have previously been used by space research, pharmaceuticals and electronics, but in the last decade several nanotechnology-based thermal insulation materials have appeared in building industry. Nowadays they only feature in a narrow range of practice, but they offer many potential applications. These options are unknown to most architects, who may simply be afraid of these materials owing to the incomplete and often contradictory special literature. Therefore, they are distrustful and prefer to apply the usual and conventional technologies. This article is intended to provide basic information about nanotechnology-based thermal insulation materials for designers. It describes their most important material properties, functional principles, applications, and potential usage options in building construction.

  4. Neutron and gamma irradiation effects on organic insulating materials for fusion magnets

    International Nuclear Information System (INIS)

    Maurer, W.

    1985-10-01

    Available low-temperature neutron and gamma irradiation data for organic insulating materials are collected and compared with room temperature data. Only the most promising polymers in terms of mechanical strength for magnet insulation are taken into account. For characterization and comparison of different materials the 75% dose is used, i.e. the dose, where the mechanical strength is reduced by 25%, and 75% is retained. For room temperature special prepared polyimide and epoxy materials reinforced with glass fibre retained 75% of the mechanical strength up to a dose of 7x10 7 Gy. For 5 K irradiation the best epoxy material retained the 75% dose up to 1x10 7 Gy, the best polyimide material up to 1x10 8 Gy. (orig.) [de

  5. Advanced Insulation Materials for Cryogenic Propellant Storage Applications, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Materials Technology, Inc responds to the NASA solicitation Topic X9 entitled "Propulsion and Propellant Storage" under subtopic X9-01, "Long Term Cryogenic...

  6. Effects of gamma-rays irradiation on tracking resistance of organic insulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Du, Boxue; Suzuki, Akio; Kobayashi, Shigeo [Tokyo Univ. of Agriculture and Technology, Koganei (Japan). Faculty of Technology

    1996-04-01

    This paper describes the influence of gamma-rays irradiation on tracking failure of organic insulating materials by use of the IEC Publ.112 method. Tracking resistance of organic insulating materials under wet polluted condition has been studied by many investigators with a test method of the IEC Publ.112. The investigations on irradiation effects on tracking resistance should be enhanced due to the increasing usage of organic insulating materials in the radiation environments. The tracking resistance seems to be affected by gamma-irradiation, but the knowledge on the influence of gamma-irradiation is quite a few and systematic studies are needed. In this paper, modified polyphenylene oxide, polybutylene naphthalate, modified polycarbonate and polybutylene terephthalate which were irradiated in air until 1x10{sup 7}R and 1x10{sup 8}R with dose rate of 10{sup 6}R/hr using {sup 60}Co gamma-source have been employed. The total dose effects on the number of drops to tracking failure, contact angle and charges of scintillation have been studied. As the total doses are increased, the number of drops to tracking failure decreases with polybutylene terephthalate. On the other hand, the number of drops to tracking failure increases with polybutylene naphthalate and modified polycarbonate when the total doses are increased. The effects of gamma-rays irradiation on tracking failure are due to radiation-induced degradation or cross-linking of organic insulating materials. When the organic insulating materials are degraded by gamma-irradiation, the tracking resistance decreases, but for cross-linking type materials, the tracking resistance increases. (author)

  7. Accelerated Aging Effect on Epoxy-polysiloxane Polymeric Insulator Material with Rice Husk Ash Filler

    Directory of Open Access Journals (Sweden)

    Rochmadi .

    2012-12-01

    Full Text Available The performances of outdoor polymeric insulators are influenced by environmental conditions. This paper presents the effect of artificial tropical climate on the hydrophobicity, equivalent salt deposit density (ESDD, surface leakage current, flashover voltage, and surface degradation on epoxy-polysiloxane polymeric insulator materials with rice husk ash (RHA. Test samples are made at room temperature vulcanized (RTV of various composition of epoxy-polysiloxane with rice husk ash as filler. The aging was carried out in test chamber at temperature from 50oC to 62oC, relative humidity of 60% to 80%, and ultraviolet (UV  radiation 21.28 w/cm2 in daylight conditions for 96 hours. The experiment results showed that the flashover voltage fluctuates from 34.13 kV up to 40.92 kV and tends to decrease on each variation of material composition. The surface leakage current fluctuates and tends to increase. Test samples with higher filler content result greater hydrophobicity, smaller equivalent salt deposit density, and smaller critical leakage current, which caused the increase of the flashover voltage. Insulator material (RTVEP3 showed the best performance in tropical climate environment. Artificial tropical aging for short duration gives less effect to the surface degradation of epoxy-polysiloxane insulator material.

  8. Uncertainty relations and topological-band insulator transitions in 2D gapped Dirac materials

    International Nuclear Information System (INIS)

    Romera, E; Calixto, M

    2015-01-01

    Uncertainty relations are studied for a characterization of topological-band insulator transitions in 2D gapped Dirac materials isostructural with graphene. We show that the relative or Kullback–Leibler entropy in position and momentum spaces, and the standard variance-based uncertainty relation give sharp signatures of topological phase transitions in these systems. (paper)

  9. The Effect of Moisture and Fungus on Electrical and Mechanical Properties of Plastic Insulating Materials

    Science.gov (United States)

    1945-10-01

    0110 106 280000 46000 7.6 30000 6.2 27000 4.2 24000 1.2 10000 Samples and eleotrode arrangement were humidity exposure tests« aa...VARIOUS INSULATING MATERIALS TEMPERATURE 25°C.; RELATIVE HUMIDITY 979b; EXCEPT WHERE NOTED OTHERWISE 140 160 ISO 200 220 240 260 270

  10. Topological insulator materials and nanostructures for future electronics, spintronics and energy conversion

    International Nuclear Information System (INIS)

    Kantser, Valeriu

    2011-01-01

    Two fundamental electrons attributes in materials and nanostructures - charge and spin - determine their electronic properties. The processing of information in conventional electronic devices is based only on the charge of the electrons. Spin electronics, or spintronics, uses the spin of electrons, as well as their charge, to process information. Metals, semiconductors and insulators are the basic materials that constitute the components of electronic devices, and these have been transforming all aspects of society for over a century. In contrast, magnetic metals, half-metals, magnetic semiconductors, dilute magnetic semiconductors and magnetic insulators are the materials that will form the basis for spintronic devices. Materials with topological band structure attributes and having a zero-energy band gap surface states are a special class of these materials that exhibit some fascinating and superior electronic properties compared to conventional materials allowing to combine both charge and spin functionalities. This article reviews a range of topological insulator materials and nanostructures with tunable surface states, focusing on nanolayered and nanowire like structures. These materials and nanostructures all have intriguing physical properties and numerous potential practical applications in spintronics, electronics, optics and sensors.

  11. Mass loss and flammability of insulation materials used in sandwich panels during the pre-flashover phase of fire

    NARCIS (Netherlands)

    Giunta d'Albani, A.W.; de Kluiver, L.L.; de Korte, A.C.J.; van Herpen, R.; Weewer, R.; Brouwers, H.J.H.

    2017-01-01

    Nowadays, buildings contain more and more synthetic insulation materials in order to meet the increasing energy-performance demands. These synthetic insulation materials have a different response to fire. In this study, the mass loss and flammability limits of different sandwich panels and their

  12. Field experiments on the use of phase changing materials, insulation materials and passive solar radiation in the built environment

    NARCIS (Netherlands)

    Entrop, Alexis Gerardus; Brouwers, Jos; Reinders, Angelina H.M.E.; McCarthy, J.; Foliente, G.

    2008-01-01

    This paper describes the development of an experimental research facility to assess the effectiveness of Phase Change Materials (PCM), that can be used for passive solar heating. Four test boxes are constructed representing the conventional and future Dutch building practices regarding insulation

  13. Radiation resistance of insulating materials for electric wires

    International Nuclear Information System (INIS)

    Kanemitsuya, Kazuhiko; Okuda, Tomoaki; Tachibana, Tadao; Yagi, Toshiaki; Seguchi, Tadao.

    1990-01-01

    In no halogen incombustible materials, smoke and poisonous gas generation at the time of burning is small, and corrosive gas rarely arises. Since no halogen electric wires and cables which use these material maintain safety for people and equipment in the case of fires, those are used for ships, tunnels, subways and so on. Also in nuclear power stations, the demand for no halogen cables becomes high although the condition of adoption is difficult. In this study, for the purpose of developing the no halogen cables for nuclear power stations, the basic data on the radiation resistance of no halogen incombustible materials were collected, and by using chemical analysis method, the radiation deterioration behavior was examined. The samples were those with base polymers of VLDPE, ULDPE, EEA, EMA and EVA. Gamma ray irradiation, tensile test, chemi-luminescence measurement, and the determination of gel fraction and swelling rate were carried out. The results are reported, In no halogen materials, when ethylene system copolymer is used as the base polymer instead of PE, the composition with good radiation resistance can be obtained, and by combining amine oxidation inhibitor, it is further improved. (K.I.)

  14. Aerogels: transparent and super-insulating materials; Les aerogels: isolants transparent-super isolants

    Energy Technology Data Exchange (ETDEWEB)

    Melka, S.; Rigacci, A.; Achard, P.; Bezian, J.J. [Ecole des Mines de Paris, 06 - Sophia-Antipolis (France); Sallee, H.; Chevalier, B. [Centre des Sciences et Techniques du Batiment, 38 - Saint-Martin-d`Heres (France)

    1996-12-31

    Recent studies have demonstrated the super-insulating properties of silica aerogel in its monolithic or finely divided state. In its monolithic state, this material conciliates excellent thermal insulation performances, a good transmission of visible light and interesting acoustic properties. Also its amazing structural characteristics (lightness, high global porosity, small diameter of pores) are particularly interesting for its use in double glazing windows as transparent insulating spacer. The aim of the work carried out by the Energetic Centre of the Ecole des Mines of Paris is to understand the thermal transfer phenomena in all forms of silica aerogel. In this paper, the main steps of the synthesis process of monolithic silica aerogel is presented with the thermal conductivities obtained. Then, a model is built to describe the thermal transfer mechanisms in finely divided aerogel beds. Finally, the hot wire thermal characterization method is presented and the results obtained on silica aerogels are discussed. (J.S.) 16 refs.

  15. Irradiation and testing of compact ignition tokamak toroidal field coil insulation materials

    International Nuclear Information System (INIS)

    Kanemoto, G.K.; Sherick, M.J.; Sparks, D.C.

    1990-05-01

    This report documents the results of an irradiation and testing program performed on behalf of Martin Marietta Energy Systems, Inc. in support of the Compact Ignition Tokamak Research and Development program. The purpose of the irradiation and testing program was to determine the effects of neutron and gamma irradiation on the mechanical and electrical properties of candidate toroidal field coil insulation materials. Insulation samples were irradiated in the Advanced Test Reactor (ATR) in a large I-hole. The insulation samples were irradiated within a lead shield to reduce exposure to gamma radiation to better approximate the desired ration of neutron to gamma exposure. Two different exposure levels were specified for the insulation samples. To accomplish this, the samples were encapsulated in two separate aluminum capsules; the capsules positioned at the ATR core mid-plane and at the top of the fueled region to take advantage of the axial cosine distribution of the neutron and gamma flux; and by varying the length of irradiation time of the two capsules. Disassembly of the irradiated capsules and testing of the insulation samples were performed at the Test Reactor Area (TRA) Hot Cell Facilities. Testing of the samples included shear compression static, shear compression fatigue, flexure static, and electrical resistance measurements

  16. Influence of LOCA simulating conditions on the variation of electrical characteristics of insulating materials

    International Nuclear Information System (INIS)

    Okada, Sohei; Yoshikawa, Masato; Ito, Masayuki; Kusama, Yasuo; Yagi, Toshiaki

    1982-01-01

    The authors have examined the variation of insulation resistance when the sheets of insulating materials and cables were exposed to various LOCA simulating environment. This report describes the summarized results obtained so far for ethylene propylene rubber (EPR) which is important as an insulating material of cables. The samples used were an EPR sheet of standard compound ratio, 2 kinds of EPR sheets of practical compound ratio, 6 types of PH cables (fire-retardant, EPR insulated, chlorosulphonated polyethylene sheathed cable) produced for trial as reactor use, and 6 kinds of EPR sheets of the same composition as the cable core. To discuss the difference of insulation resistance change, the logarithmic mean of the ratio of 1 min values to initial insulation resistance rho/rhosub(o) was used. PWR LOCA-simulating environment was used, while the thermal aging in the air at 121 deg C for 7 days and 50 Mrad irradiation in the air at room temperature were given as the predeterioration. The effect of LOCA-simulation period in the simultaneous method without air, in which steam and radiation were given in parallel, the difference in the experimental results of cables and sheets, the effect of air, the comparison of the simultaneous method with the sequential method in which LOCA-simulating steam was applied after the irradiation in the air and the reverse sequential method (dielectric property measurements) are described. Under the existence of air, the sequential method seems to be a good simulation condition for the simultaneous method, though many experiments are required further. (Wakatsuki, Y.)

  17. Influence of LOCA simulating conditions on the variation of electrical characteristics of insulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Sohei; Yoshikawa, Masato; Ito, Masayuki; Kusama, Yasuo; Yagi, Toshiaki

    1982-12-01

    The authors have examined the variation of insulation resistance when the sheets of insulating materials and cables were exposed to various LOCA simulating environment. This report describes the summarized results obtained so far for ethylene propylene rubber (EPR) which is important as an insulating material of cables. The samples used were an EPR sheet of standard compound ratio, 2 kinds of EPR sheets of practical compound ratio, 6 types of PH cables (fire-retardant, EPR insulated, chlorosulphonated polyethylene sheathed cable) produced for trial as reactor use, and 6 kinds of EPR sheets of the same composition as the cable core. To discuss the difference of insulation resistance change, the logarithmic mean of the ratio of 1 min values to initial insulation resistance rho/rhosub(o) was used. PWR LOCA-simulating environment was used, while the thermal aging in the air at 121 deg C for 7 days and 50 Mrad irradiation in the air at room temperature were given as the predeterioration. The effect of LOCA-simulation period in the simultaneous method without air, in which steam and radiation were given in parallel, the difference in the experimental results of cables and sheets, the effect of air, the comparison of the simultaneous method with the sequential method in which LOCA-simulating steam was applied after the irradiation in the air and the reverse sequential method (dielectric property measurements) are described. Under the existence of air, the sequential method seems to be a good simulation condition for the simultaneous method, though many experiments are required further.

  18. Non-isothermal Moisture Transport Through Insulation Materials

    DEFF Research Database (Denmark)

    Peuhkuri, Ruut Hannele; Rode, Carsten; Hansen, Kurt Kielsgaard

    2008-01-01

    An experimental investigation was conducted in order to draw some conclusions on the magnitude of moisture transport due to temperature gradient on a range of porous light-weight building materials. A special constructed non-isothermal set-up allowed the creation of a temperature gradient of 10K...... and given humidity gradient over the sample. The resulting moisture ux as well as the hygrothermal states around and within the material were monitored. The hypothesis of relative humidity being a driving force for non-isothermal moisture transport already in the hygroscopic range could not be confirmed....... On the contrary, indications exist that the temperature gradient itself is driving the moisture from the warm side towards the cold side. An attempt to identify and quantify the single contributions of the different transport forms involved is also presented. The diferent results gave, however, diverging...

  19. RESTORING A DAMAGED 16-YEAR -OLD INSULATING POLYMER CONCRETE DIKE OVERLAY: REPAIR MATERIALS AND TECHNOLOGIES.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA,T.

    2007-01-01

    The objective of this program was to design and formulate organic polymer-based material systems suitable for repairing and restoring the overlay panels of insulating lightweight polymer concrete (ILPC) from the concrete floor and slope wall of a dike at KeySpan liquefied natural gas (LNG) facility in Greenpoint, Brooklyn, NY, just over sixteen years ago. It also included undertaking a small-scale field demonstration to ensure that the commercial repairing technologies were applicable to the designed and formulated materials.

  20. Cryogenic Properties of Inorganic Insulation Materials for ITER Magnets: A Review

    International Nuclear Information System (INIS)

    Simon, N.J.

    1994-01-01

    Results of a literature search on the cryogenic properties of candidate inorganic insulators for the ITER TF magnets are reported. The materials investigated include: Al 2 O 3 , AlN, MgO, porcelain, SiO 2 , MgAl 2 O 4 , ZrO 2 , and mica. A graphical presentation is given of mechanical, elastic, electrical, and thermal properties between 4 and 300 K. A companion report reviews the low temperature irradiation resistance of these materials

  1. Setting of loose-fill insulation materials in walls; Saetningsfri indblaesning af loesfyldsisolering i vaegge

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, T.V.

    2001-07-01

    The report describes material behaviour, which significantly influences the settling of loose-fill insulation materials. The specific application presented here is loose-fill insulation material injected in walls as thermal insulation. The physical formulation of the issue to be discussed is that the mass is kept in position in the cavity by frictional forces, which counteracts the settling but complicates injection. The purpose of this study is to investigate whether there is a possibility that decreased friction will be able to release settling. Cellulose loose-fill material injected in a 0.1 m thick and 1 m wide gypsum wall with a minimum density of 48 kg/m3 was found not to settle if kept at a constant relative humidity, RH 50 %. A minimum density of 53 kg/m3 is necessary if the thickness of the wall is increased from 0.1 m to 0.3 m. If changing the constant environment from RH 50 % to RH 80 % a minimum density of 63 kg/m3 is necessary. Furthermore, results so far show that cellulose loose-fill material spread on the attic floor will have a density after settling of 48 kg /M3 for a constant RH 50 %, corresponding to 43 kg/m3 dry material. The results were found by using a model and tests. (au)

  2. Radiation hardness of superconducting magnet insulation materials for FAIR

    International Nuclear Information System (INIS)

    Seidl, Tim

    2013-03-01

    This thesis focuses on radiation degradation studies of polyimide, polyepoxy/glass-fiber composites and other technical components used, for example, in the superconducting magnets of new ion accelerators such as the planned International Facility for Antiproton and Ion Research (FAIR) at the GSI Helmholtz Center of Heavy Ion Research (GSI) in Darmstadt. As accelerators are becoming more powerful, i.e., providing larger energies and beam intensities, the potential risk of radiation damage to the components increases. Reliable data of the radiation hardness of accelerator materials and components concerning electrical, thermal and other technical relevant properties are of great interest also for other facilities such as the Large Hadron Collider (LHC) of CERN. Dependent on the position of the different components, induced radiation due to beam losses consists of a cocktail of gammas, neutrons, protons, and heavier particles. Although the number of heavy fragments of the initial projectiles is small compared to neutrons, protons, or light fragments (e.g. ? particles), their large energy deposition can induce extensive damage at rather low fluences (dose calculations show that the contribution of heavy ions to the total accumulated dose can reach 80 %). For this reason, defined radiation experiments were conducted using different energetic ion beams (from protons to uranium) and gamma radiation from a Co-60 source. The induced changes were analyzed by means of in-situ and ex-situ analytical methods, e.g. ultraviolet-visible and infrared spectroscopy, residual gas analysis, thermal gravimetric analysis, dielectric strength measurements, measurements of low temperature thermal properties, and performance tests. In all cases, the radiation induces a change in molecular structure as well as loss of functional material properties. The amount of radiation damage is found to be sensitive to the used type of ionizing radiation and the long term stability of the materials is

  3. Investigation of electrophysical properties of electrical insulating materials under neutron irradiation

    International Nuclear Information System (INIS)

    Skornyakov, Yu.A.; Stepanov, A.N.; Lapenas, A.A.

    1978-01-01

    The possibilities of applicaiton of insulating materials on the basis of glass cloths in electric windings for operation under neutron radiation of thermonuclear devices are studied. Changes in the specimen resistance, tangent of the angle of dielectric losses, electric strength according to the value of neutron fluence are determined. The temperature regimes are also studied. The data indicate the irreversible changes in the composition and structure of the polymer material under irradiation. The LSMI 228L-80 glass cloth has the highest radiation resistance. The necessity of forced cooling of large-sized specimens under the neutron radiation the IRT-200 reactor is established. The presence of impurities leading to the long-term induced activity of the insulating materials ( 59 Fe, 60 Co) is determined

  4. Effect of nuclear track on reflectivity for insulating material

    International Nuclear Information System (INIS)

    Liu Cunxiong; Ni Bangfa; Tian Weizhi; Hu Lian; Xiao Caijin; Wang Pingsheng; Zhang Guiying; Huang Donghui; Lu Peng; Yang Weitao

    2009-01-01

    Polyester and CR-39 samples were irradiated with sulphur ion from HI-13 tandem accelerator. Ultraviolet light with wavelength 360 nm was used to sensitize the polymer before chemical etching by NaOH solution with different temperatures and time duration. The latent track was then developed into nanometer to micrometer pore with certain depth. Samples were coated with thin layer of silver and magnesium fluoride using the vacuum evaporator. The reflectivity and transmission index were measured for all polymer samples, untreated and treated with above-mentioned procedure, within the wavelength of visible light. Solid state nuclear track and coating can reduce reflectivity of tested polymer materials greatly, and the reflectivity can be 1% or lower. (authors)

  5. Nanostructure multilayer dielectric materials for capacitors and insulators

    Science.gov (United States)

    Barbee, Jr., Troy W.; Johnson, Gary W.

    1998-04-21

    A capacitor is formed of at least two metal conductors having a multilayer dielectric and opposite dielectric-conductor interface layers in between. The multilayer dielectric includes many alternating layers of amorphous zirconium oxide (ZrO.sub.2) and alumina (Al.sub.2 O.sub.3). The dielectric-conductor interface layers are engineered for increased voltage breakdown and extended service life. The local interfacial work function is increased to reduce charge injection and thus increase breakdown voltage. Proper material choices can prevent electrochemical reactions and diffusion between the conductor and dielectric. Physical vapor deposition is used to deposit the zirconium oxide (ZrO.sub.2) and alumina (Al.sub.2 O.sub.3) in alternating layers to form a nano-laminate.

  6. Insulation Cork Boards—Environmental Life Cycle Assessment of an Organic Construction Material

    Directory of Open Access Journals (Sweden)

    José D. Silvestre

    2016-05-01

    Full Text Available Envelope insulation is a relevant technical solution to cut energy consumption and reduce environmental impacts in buildings. Insulation Cork Boards (ICB are a natural thermal insulation material whose production promotes the recycling of agricultural waste. The aim of this paper is to determine and evaluate the environmental impacts of the production, use, and end-of-life processing of ICB. A “cradle-to-cradle” environmental Life Cycle Assessment (LCA was performed according to International LCA standards and the European standards on the environmental evaluation of buildings. These results were based on site-specific data and resulted from a consistent methodology, fully described in the paper for each life cycle stage: Cork oak tree growth, ICB production, and end-of-life processing-modeling of the carbon flows (i.e., uptakes and emissions, including sensitivity analysis of this procedure; at the production stage—the modeling of energy processes and a sensitivity analysis of the allocation procedures; during building operation—the expected service life of ICB; an analysis concerning the need to consider the thermal diffusivity of ICB in the comparison of the performance of insulation materials. This paper presents the up-to-date “cradle-to-cradle” environmental performance of ICB for the environmental categories and life-cycle stages defined in European standards.

  7. Insulation Cork Boards—Environmental Life Cycle Assessment of an Organic Construction Material

    Science.gov (United States)

    Silvestre, José D.; Pargana, Nuno; de Brito, Jorge; Pinheiro, Manuel D.; Durão, Vera

    2016-01-01

    Envelope insulation is a relevant technical solution to cut energy consumption and reduce environmental impacts in buildings. Insulation Cork Boards (ICB) are a natural thermal insulation material whose production promotes the recycling of agricultural waste. The aim of this paper is to determine and evaluate the environmental impacts of the production, use, and end-of-life processing of ICB. A “cradle-to-cradle” environmental Life Cycle Assessment (LCA) was performed according to International LCA standards and the European standards on the environmental evaluation of buildings. These results were based on site-specific data and resulted from a consistent methodology, fully described in the paper for each life cycle stage: Cork oak tree growth, ICB production, and end-of-life processing-modeling of the carbon flows (i.e., uptakes and emissions), including sensitivity analysis of this procedure; at the production stage—the modeling of energy processes and a sensitivity analysis of the allocation procedures; during building operation—the expected service life of ICB; an analysis concerning the need to consider the thermal diffusivity of ICB in the comparison of the performance of insulation materials. This paper presents the up-to-date “cradle-to-cradle” environmental performance of ICB for the environmental categories and life-cycle stages defined in European standards. PMID:28773516

  8. Insulation Cork Boards-Environmental Life Cycle Assessment of an Organic Construction Material.

    Science.gov (United States)

    Silvestre, José D; Pargana, Nuno; de Brito, Jorge; Pinheiro, Manuel D; Durão, Vera

    2016-05-20

    Envelope insulation is a relevant technical solution to cut energy consumption and reduce environmental impacts in buildings. Insulation Cork Boards (ICB) are a natural thermal insulation material whose production promotes the recycling of agricultural waste. The aim of this paper is to determine and evaluate the environmental impacts of the production, use, and end-of-life processing of ICB. A "cradle-to-cradle" environmental Life Cycle Assessment (LCA) was performed according to International LCA standards and the European standards on the environmental evaluation of buildings. These results were based on site-specific data and resulted from a consistent methodology, fully described in the paper for each life cycle stage: Cork oak tree growth, ICB production, and end-of-life processing-modeling of the carbon flows ( i.e. , uptakes and emissions), including sensitivity analysis of this procedure; at the production stage-the modeling of energy processes and a sensitivity analysis of the allocation procedures; during building operation-the expected service life of ICB; an analysis concerning the need to consider the thermal diffusivity of ICB in the comparison of the performance of insulation materials. This paper presents the up-to-date "cradle-to-cradle" environmental performance of ICB for the environmental categories and life-cycle stages defined in European standards.

  9. The Role of Interfaces in Polyethylene/Metal-Oxide Nanocomposites for Ultrahigh-Voltage Insulating Materials.

    Science.gov (United States)

    Pourrahimi, Amir Masoud; Olsson, Richard T; Hedenqvist, Mikael S

    2018-01-01

    Recent progress in the development of polyethylene/metal-oxide nanocomposites for extruded high-voltage direct-current (HVDC) cables with ultrahigh electric insulation properties is presented. This is a promising technology with the potential of raising the upper voltage limit in today's underground/submarine cables, based on pristine polyethylene, to levels where the loss of energy during electric power transmission becomes low enough to ensure intercontinental electric power transmission. The development of HVDC insulating materials together with the impact of the interface between the particles and the polymer on the nanocomposites electric properties are shown. Important parameters from the atomic to the microlevel, such as interfacial chemistry, interfacial area, and degree of particle dispersion/aggregation, are discussed. This work is placed in perspective with important work by others, and suggested mechanisms for improved insulation using nanoparticles, such as increased charge trap density, adsorption of impurities/ions, and induced particle dipole moments are considered. The effects of the nanoparticles and of their interfacial structures on the mechanical properties and the implications of cavitation on the electric properties are also discussed. Although the main interest in improving the properties of insulating polymers has been on the use of nanoparticles, leading to nanodielectrics, it is pointed out here that larger microscopic hierarchical metal-oxide particles with high surface porosity also impart good insulation properties. The impact of the type of particle and its inherent properties (purity and conductivity) on the nanocomposite dielectric and insulating properties are also discussed based on data obtained by a newly developed technique to directly observe the charge distribution on a nanometer scale in the nanocomposite. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. A simple approach to measure the surface resistivity of insulating materials

    DEFF Research Database (Denmark)

    Yang, Zhenyu; Wang, Qian

    2011-01-01

    A simple approach for measuring high surface resistivity of insulating materials using standard laboratory equipments is proposed. The developed system consists of a DC power transformer, a concentric ring probe assembly and a digital multi-meter. The DC power transformer can provide either 500V ...... for different materials, source voltages, and serially connected resistors. The testing results showed that the developed system and methods can provide a reasonably accurate measurement of surface resistivity of insulating materials in a robust and economic manner.......A simple approach for measuring high surface resistivity of insulating materials using standard laboratory equipments is proposed. The developed system consists of a DC power transformer, a concentric ring probe assembly and a digital multi-meter. The DC power transformer can provide either 500V...... or 250V DC signal. The probe assembly is constructed according to Danish Standard (DS/EN 1149-1:2006). The multi-meter (Agilent 3440 1A 6½) is used to measure the micro voltage over a known resistor which is serially connected with electrodes in the probe assembly. In order to obtain reliable...

  11. Treeing phenomenon of thermoplastic polyethylene blends for recyclable cable insulation materials

    Science.gov (United States)

    Li, Lunzhi; Zhang, Kai; Zhong, Lisheng; Gao, Jinghui; Xu, Man; Chen, Guanghui; Fu, Mingli

    2017-02-01

    Owing to its good recyclability and low processing energy consumption, non-crosslinked polyethylene blends (e.g. LLDPE-HDPE blends) are considered as one of potential environmental-friendly substitutions for crosslinked polyethylene (XLPE) as cable insulation material. Although extensive work has been performed for measuring the basic dielectric properties, there is a lack of the investigations on the aging properties for such a material system, which hinders the evaluation of reliability and lifetime of the material for cable insulation. In this paper, we study the electric aging phenomenon of 0.7LLDPE-0.3HDPE blending material by investigating the treeing behavior, and its comparison with XLPE and LLDPE. Treeing tests show that the 0.7LLDPE-0.3HDPE blends have lower probability for treeing as well as smaller treeing dimensions. Further thermal analysis and microstructure study results suggest that the blends exhibit larger proportion of thick lamellae and higher crystallinity with homogeneously-distributed amorphous region, which is responsible for good anti-treeing performance. Our finding provides the evidence that the 0.7LLDPE-0.3HDPE blends exhibits better electric-aging-retardance properties than XLPE, which may result in a potential application for cable insulation.

  12. Treeing phenomenon of thermoplastic polyethylene blends for recyclable cable insulation materials

    Directory of Open Access Journals (Sweden)

    Lunzhi Li

    2017-02-01

    Full Text Available Owing to its good recyclability and low processing energy consumption, non-crosslinked polyethylene blends (e.g. LLDPE-HDPE blends are considered as one of potential environmental-friendly substitutions for crosslinked polyethylene (XLPE as cable insulation material. Although extensive work has been performed for measuring the basic dielectric properties, there is a lack of the investigations on the aging properties for such a material system, which hinders the evaluation of reliability and lifetime of the material for cable insulation. In this paper, we study the electric aging phenomenon of 0.7LLDPE-0.3HDPE blending material by investigating the treeing behavior, and its comparison with XLPE and LLDPE. Treeing tests show that the 0.7LLDPE-0.3HDPE blends have lower probability for treeing as well as smaller treeing dimensions. Further thermal analysis and microstructure study results suggest that the blends exhibit larger proportion of thick lamellae and higher crystallinity with homogeneously-distributed amorphous region, which is responsible for good anti-treeing performance. Our finding provides the evidence that the 0.7LLDPE-0.3HDPE blends exhibits better electric-aging-retardance properties than XLPE, which may result in a potential application for cable insulation.

  13. Effect of resin composition to the electrical and mechanical properties of high voltage insulator material

    International Nuclear Information System (INIS)

    Totok Dermawan; Elin Nuraini; Suyamto

    2012-01-01

    A solid insulator manufacture of resins for high voltage with a variation of resin and hardener composition has been made. The purpose of research to know electrical and mechanical properties of high voltage insulator material of resin. To determine its electric properties, the material is tested its breakdown voltage and the flashover voltage that occurred on the surface. While to determine the mechanical properties were tested by measuring its strength with a tensile test. From testing with variety of mixed composition it is known that for composition between hardener and resin of 1 : 800 has most advantageous properties because it has good strength with a tensile strength of 19.86 MPa and enough high dielectric strength of 43.2 kV / mm). (author)

  14. Safety distance for preventing hot particle ignition of building insulation materials

    Directory of Open Access Journals (Sweden)

    Jiayun Song

    2014-01-01

    Full Text Available Trajectories of flying hot particles were predicted in this work, and the temperatures during the movement were also calculated. Once the particle temperature decreased to the critical temperature for a hot particle to ignite building insulation materials, which was predicted by hot-spot ignition theory, the distance particle traveled was determined as the minimum safety distance for preventing the ignition of building insulation materials by hot particles. The results showed that for sphere aluminum particles with the same initial velocities and diameters, the horizontal and vertical distances traveled by particles with higher initial temperatures were higher. Smaller particles traveled farther when other conditions were the same. The critical temperature for an aluminum particle to ignite rigid polyurethane foam increased rapidly with the decrease of particle diameter. The horizontal and vertical safety distances were closely related to the initial temperature, diameter and initial velocity of particles. These results could help update the safety provision of firework display.

  15. Metal - Insulator Transition Driven by Vacancy Ordering in GeSbTe Phase Change Materials

    OpenAIRE

    Bragaglia, Valeria; Arciprete, Fabrizio; Privitera, Stefania; Rimini, Emanuele; Mazzarello, Riccardo; Calarco, Raffaella; Zhang, Wei; Mio, Antonio Massimiliano; Zallo, Eugenio; Perumal, Karthick; Giussani, Alessandro; Cecchi, Stefano; Boschker, Jos Emiel; Riechert, Henning

    2016-01-01

    Phase Change Materials (PCMs) are unique compounds employed in non-volatile random access memory thanks to the rapid and reversible transformation between the amorphous and crystalline state that display large differences in electrical and optical properties. In addition to the amorphous-to-crystalline transition, experimental results on polycrystalline GeSbTe alloys (GST) films evidenced a Metal-Insulator Transition (MIT) attributed to disorder in the crystalline phase. Here we report on a f...

  16. Investigation of cryogenic irradiation influence on mechanical and physical properties of ITER magnetic system insulation materials

    International Nuclear Information System (INIS)

    Kozlov, A.V.; Scherbacov, E.N.; Dudchenko, N.A.; Shihalev, V.S.; Bedin, V.V.; Paltusov, N.A.; Korsunskiy, V.E.

    1998-01-01

    A set of methods of cryogenic irradiation influence test on mechanical and physical properties of insulation of ITER magnetic system are presented in this paper. Investigations are carried out without intermediate warming up of samples. A Russian insulating composite material was irradiated in the IVV-2M reactor. The ratio of energy absorbed by insulation materials from neutron irradiation to that from gamma irradiation can be varied from ∝(25:75)% to ∝(50:50)% in the reactor. The test results on the thermal expansion, thermal conductivity and gas evolution of the above material are presented. It was shown, that cryogenic irradiation up to the fluence ∝2 x 10 22 n/m 2 (E ≥ 0.1 MeV) leads to 0.27% linear size changes along layers of fiber-glass, the thermal conductivity coefficient is decreased on 15% at 100 k in perpendicular direction to fiber-glass plane, and thermal coefficient of linear expansion (TCLE) has anomalous temperature dependence. (orig.)

  17. Radiation tests on selected electrical insulating materials for high-power and high voltage application

    International Nuclear Information System (INIS)

    Liptak, G.; Schuler, R.; Haberthuer, B.; Mueller, H.; Zeier, W.; Maier, P.; Schoenbacher, H.

    1985-01-01

    This report presents a comprehensive set of test results on the irradiation of insulating materials and systems used for the windings of rotating machines, dry-type transformers, and magnet coils. The materials were: Novolac, bisphenol-A, and cycloaliphatic types of epoxy; saturated and unsaturated polyesterimide; silicone, phenolic, and acrylic resins. The reinforcement consisted of glass mat, glass roving, glass cloth, mica paper, polyester mat, polyester roving, polyester cloth, aromatic polyamide paper, or combinations thereof. The materials were irradiated in an 8 MW pool reactor up to integrated doses of 10 8 Gy. On most samples, flexural properties were examined as recommended by IEC Standard 544. For tapes and varnishes, the breakdown voltage was measured. The adhesion of copper bars glued together with an epoxy resin was examined by means of a lap-shear test. A cupping test by means of the Erichsen apparatus was used to measure the flexibility of varnishes. The results are presented in tables and graphs for each of the materials tested. Those from mechanical tests show that the radiation resistance of composite resin-rich insulations depends not only on the base resin combination and the reinforcement material but, to a large degree, also on the adhesion between the two. It appears that better adhesion, and consequently higher radiation resistance, is obtained by special surface treatments of glass fibres. For laminates, higher radiation resistance is obtained with glass mat and resin combinations than with glass cloth as reinforcing materials. The breakdown voltage tests show that the application of mechanical stress to most irradiated samples causes the insulation layer to crack, resulting in lower dielectric strength. For a number of materials, the critical properties of flexural strength and breakdown voltage are above 50% of the initial value at doses between 10 7 and 10 8 Gy, i.e. a radiation index of 7 to 8 at 10 5 Gy/h. (orig.)

  18. Metal-insulator transition and superconductivity in heavily boron-doped diamond and related materials

    Energy Technology Data Exchange (ETDEWEB)

    Achatz, Philipp

    2009-05-15

    During this PhD project, the metal-insulator transition and superconductivity of highly boron-doped single crystal diamond and related materials have been investigated. The critical boron concentration n{sub c} for the metal-insulator transition was found to be the same as for the normal-superconductor transition. All metallic samples have been found to be superconducting and we were able to link the occurence of superconductivity to the proximity to the metal-insulator transition. For this purpose, a scaling law approach based on low temperature transport was proposed. Furthermore, we tried to study the nature of the superconductivity in highly boron doped single crystal diamond. Raman spectroscopy measurements on the isotopically substituted series suggest that the feature occuring at low wavenumbers ({approx} 500 cm{sup -1}) is the A1g vibrational mode associated with boron dimers. Usual Hall effect measurements yielded a puzzling situation in metallic boron-doped diamond samples, leading to carrier concentrations up to a factor 10 higher than the boron concentration determined by secondary ion mass spectroscopy (SIMS). The low temperature transport follows the one expected for a granular metal or insulator, depending on the interplay of intergranular and intragranular (tunneling) conductance. The metal-insulator transition takes place at a critical conductance g{sub c}. The granularity also influences significantly the superconducting properties by introducing the superconducting gap {delta} in the grain and Josephson coupling J between superconducting grains. A peak in magnetoresistance is observed which can be explained by superconducting fluctuations and the granularity of the system. Additionally we studied the low temperature transport of boron-doped Si samples grown by gas immersion laser doping, some of which yielded a superconducting transition at very low temperatures. Furthermore, preliminary results on the LO-phonon-plasmon coupling are shown for the

  19. Metal-insulator transition and superconductivity in heavily boron-doped diamond and related materials

    International Nuclear Information System (INIS)

    Achatz, Philipp

    2009-01-01

    During this PhD project, the metal-insulator transition and superconductivity of highly boron-doped single crystal diamond and related materials have been investigated. The critical boron concentration n c for the metal-insulator transition was found to be the same as for the normal-superconductor transition. All metallic samples have been found to be superconducting and we were able to link the occurence of superconductivity to the proximity to the metal-insulator transition. For this purpose, a scaling law approach based on low temperature transport was proposed. Furthermore, we tried to study the nature of the superconductivity in highly boron doped single crystal diamond. Raman spectroscopy measurements on the isotopically substituted series suggest that the feature occuring at low wavenumbers (∼ 500 cm -1 ) is the A1g vibrational mode associated with boron dimers. Usual Hall effect measurements yielded a puzzling situation in metallic boron-doped diamond samples, leading to carrier concentrations up to a factor 10 higher than the boron concentration determined by secondary ion mass spectroscopy (SIMS). The low temperature transport follows the one expected for a granular metal or insulator, depending on the interplay of intergranular and intragranular (tunneling) conductance. The metal-insulator transition takes place at a critical conductance g c . The granularity also influences significantly the superconducting properties by introducing the superconducting gap Δ in the grain and Josephson coupling J between superconducting grains. A peak in magnetoresistance is observed which can be explained by superconducting fluctuations and the granularity of the system. Additionally we studied the low temperature transport of boron-doped Si samples grown by gas immersion laser doping, some of which yielded a superconducting transition at very low temperatures. Furthermore, preliminary results on the LO-phonon-plasmon coupling are shown for the first time in aluminum

  20. 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.

  1. Effect of air on speed of insulating material deterioration under simulated LOCA environment. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kusama, Yasuo; Yagi, Toshiaki; Ito, Masayuki; Okada, Sohei; Yoshikawa, Masato (Japan Atomic Energy Research Inst., Takasaki, Gunma. Takasaki Radiation Chemistry Research Establishment)

    1982-12-01

    To examine the quality approval testing method for the electric cables used for nuclear reactors, various covering insulating materials employed for the cables have been investigated from all angles. The factors which are considered to affect the deterioration of cable materials in a simulated LOCA (loss of coolant accident) environmental test are numerous. This paper reports on the result of investigation on the effect of air on the rate of deterioration of various organic materials usually used as the insulating and covering materials for the cables. Five kinds of polymer sheets (1 mm thick) used for reactor cables were employed as samples. The samples of both standard compounding ratio and the compounding ratio for practical reactor use were tested. As the deterioration prior to LOCA simulation, the thermal deterioration corresponding to 40 years aging (at 121 deg C for 7 days) was given, and subsequently, 50 Mrad gamma -irradiation at 1 Mrad/h was performed in the air. After that, the samples were subject to LOCA simulated environment. Since the results were different according to the kinds of samples, those are described separately for Hypalon, ethylene propylene rubber, cross-linked polyethylene, chloroprene and silicone rubber. The existence of air under LOCA environment accelerated the deterioration of insulation materials except silicone rubber, though its influence differed to the polymers. These materials swelled in the presence of air, and the degree of swelling increased with the temperature, having the close relation to oxidation deterioration. Polyethylene was more susceptible to the effect of air, and silicone rubber was rather stable. The samples of fire-retardant compounding ratio more swelled by water absorption than those of standard compounding ratio.

  2. 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.

  3. Comparative experimental and numerical studies of usual insulation materials and PCMs in buildings at Casablanca

    Science.gov (United States)

    Mourid, Amina; El Alami, Mustapha

    2018-05-01

    In this paper, we present a comparative thermal study of the usual insulation materials used in the building as well as the innovate one like phase change materials (PCMs). Both experimental study and numerical approach were applied in this work for summer season. In the experimental study the PCM was installed on the outer surface on the ceiling of one of two full-scale rooms located at FSAC, Casablanca. A simulation model was performed with TRNSYS’17 software. We have established as a criterion of comparison the internal temperatures. An economic study also has been carried out. Based on this latter, that the PCM is most efficient.

  4. Band inversion mechanism in topological insulators: A guideline for materials design

    KAUST Repository

    Zhu, Zhiyong

    2012-06-01

    Alteration of the topological order by band inversion is a key ingredient of a topologically nontrivial material. Using first-principles calculations for HgTe, PtScBi, and Bi2Se3, we argue that it is not accurate to ascribe the band inversion to the spin-orbit coupling. Instead, scalar relativistic effects and/or lattice distortions are found to be essential. Therefore, the search for topologically nontrivial materials should focus on band shifts due to these mechanisms rather than spin-orbit coupling. We propose an effective scheme to search for new topological insulators.

  5. Safety research of insulating materials of cable for nuclear power generating station

    Science.gov (United States)

    Lee, C. K.; Choi, J. H.; Kong, Y. K.; Chang, H. S.

    1988-01-01

    The polymers PE, EPR, PVC, Neoprene, CSP, CLPE, EP and other similar substances are frequently used as insulation and protective covering for cables used in nuclear power generating stations. In order to test these materials for flame retardation, environmental resistance, and cable specifications, they were given the cable normal test, flame test, chemical tests, and subjected to design analysis and loss of coolant accident tests. Material was collected on spark tests and actual experience standards were established through these contributions and technology was accumulated.

  6. Band inversion mechanism in topological insulators: A guideline for materials design

    KAUST Repository

    Zhu, Zhiyong; Cheng, Yingchun; Schwingenschlö gl, Udo

    2012-01-01

    Alteration of the topological order by band inversion is a key ingredient of a topologically nontrivial material. Using first-principles calculations for HgTe, PtScBi, and Bi2Se3, we argue that it is not accurate to ascribe the band inversion to the spin-orbit coupling. Instead, scalar relativistic effects and/or lattice distortions are found to be essential. Therefore, the search for topologically nontrivial materials should focus on band shifts due to these mechanisms rather than spin-orbit coupling. We propose an effective scheme to search for new topological insulators.

  7. 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

  8. Cryogenic Properties of Inorganic Insulation Materials for ITER Magnets: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Simon, N.J.

    1994-12-01

    Results of a literature search on the cryogenic properties of candidate inorganic insulators for the ITER TF magnets are reported. The materials investigated include: Al{sub 2}O{sub 3}, AlN, MgO, porcelain, SiO{sub 2}, MgAl{sub 2}O{sub 4}, ZrO{sub 2}, and mica. A graphical presentation is given of mechanical, elastic, electrical, and thermal properties between 4 and 300 K. A companion report reviews the low temperature irradiation resistance of these materials.

  9. Normal zone propagation characteristics of coated conductor according to insulation materials

    International Nuclear Information System (INIS)

    Yang, S.E.; Ahn, M.C.; Park, D.K.; Chang, K.S.; Bae, D.K.; Ko, T.K.

    2007-01-01

    Recent development of CC, usually called second generation (2G) HTS, is actively in progress. Because of its higher critical current density as well as higher n-value, 2G HTS is feasible for the applications such as superconducting fault current limiter and superconducting cable. For operating the HTS equipment stably, it needs to investigate the characteristics of normal zone propagation occurred by quench. Investigations on the fundamental characteristics can be one of the indispensable foundations for research and development of power equipments. In this paper, normal zone propagation (NZP) characteristics according to various insulation materials are researched. By heating with NiCr heater and insulating with epoxy, we applied the operating current with respect to the critical current for calculation of minimum quench energy (MQE) and measurement of NZP

  10. Synthesis of Macroporous Silica Particles by Continuous Generation of Droplets for Insulating Materials.

    Science.gov (United States)

    Cho, Young-Sang; Lee, Dokyoung

    2018-09-01

    We report on the synthesis of porous silica particles by self-assembly routes in a continuous manner for application to thermal insulators. A continuous process was employed to produce tiny droplets containing precursor materials such as silica and organic templates for self-organization to fabricate particles with well defined pores. A rotating cylinder system or a spray drying process was adopted to form emulsions or aerosol droplets as micro-reactors for self-assembly, and the physical properties including the thermal conductivity of the resulting porous particles were compared between the two methods. The porous particles could be coated as a thick film by solution dripping, and the fluorination treatment using a silane coupling agent was performed to produce superhydrophobic surfaces of insulating layers by a lotus effect.

  11. Safeguarding of emergency core cooling in case of loss-of-coolant accidents with insulation material release

    International Nuclear Information System (INIS)

    Pointner, W.; Broecker, A.

    2012-01-01

    The report on safeguarding of emergency core cooling in case of loss-of-coolant accidents with insulation material release covers the following issues: assessment of the relevant status for PWR, evaluation of the national and international (USA, Canada, France) status, actualization of recommendations, transferability from PWR to BWR. Generic studies on the core cooling capability in case of insulation material release in BWR-type reactors were evaluated.

  12. Analysis of Insulating Material of XLPE Cables considering Innovative Patterns of Partial Discharges

    Directory of Open Access Journals (Sweden)

    Fernando Figueroa Godoy

    2017-01-01

    Full Text Available This paper aims to analyze the quality of insulation in high voltage underground cables XLPE using a prototype which classifies the following usual types of patterns of partial discharge (PD: (1 internal PD, (2 superficial PD, (3 corona discharge in air, and (4 corona discharge in oil, in addition to considering two new PD patterns: (1 false contact and (2 floating ground. The tests and measurements to obtain the patterns and study cases of partial discharges were performed at the Testing Laboratory Equipment and Materials (LEPEM of the Federal Electricity Commission of Mexico (CFE using a measuring equipment LDIC and norm IEC60270. To classify the six patterns of partial discharges mentioned above a Probabilistic Neural Network Bayesian Modified (PNNBM method having the feature of using a large amount of data will be used and it is not saturated. In addition, PNN converges, always finding a solution in a short period of time with low computational cost. The insulation of two high voltage cables with different characteristics was analyzed. The test results allow us to conclude which wire has better insulation.

  13. Development of polymer concrete for dike insulation at LNG facilities: Phase 4, Low cost materials

    Energy Technology Data Exchange (ETDEWEB)

    Kukacka, L.E.

    1991-01-01

    Earlier GRI-sponsored work at Brookhaven National Laboratory has resulted in the development and utilization of insulating polymer concrete composites (IPC) as a means of reducing the evaporation rate of liquified natural gas in the event of a spill into a containment dike, thereby improving the safety at these sites. Although all of the required properties can be attained with the IPC, it was estimated that a low-cost replacement for the expensive organic binder would be necessary before use of the material would be cost-effective. In the current program, several latex modified cement formulations were evaluated and the most promising one identified. A mixture of two carboxylated styrene-butadiene latexes was selected for use in detailed laboratory property characterizations and a subsequent field evaluation. When compared to the properties of IPC, the latex-modified insulating materials display somewhat higher thermal conductivities, greater permeability to water, and reduced strength. However, these properties still meet most of the performance criteria, and the unit cost of the material is less than one-fifth that of IPC made with epoxy binders. When installed as a 0.75-in. thick overlay, material costs are estimated to be $1.00/ft{sup 2}.

  14. Production of a nuclear radiation resistant and mechanically tough electrically insulating material

    International Nuclear Information System (INIS)

    Brechna, H.

    1975-01-01

    According to the invention, an electrically insulating material of high mechanical strength and resistance to nuclear radiation may be made of a hardenable plastic material coated on an inorganic supporting tissue. The synthetic resin serving as binder - duroplasts, e.g. epoxide resins, polyester resins or silicon resins - is heated, mixed with a catalyst, a wetting agent and a filler (and, if required, with 0.5-1.5 weight % thixotropic material) and coated, under reduced pressure (o.4 to 0.6 mm Hg), on the supporting tissue whose surface is cleaned before this by heating. It is then hardened. Hardening may also take place directly on the electric conductor to be insulated. One obtains a bubble-free wire coating. The inorganic supporting material is glas fibre tissue, also in combination with mica, while Al 2 O 3 , zirconium, zirconia, magnesium oxide, mica and silica (grain size 10-20 μ). The invention is illustrated by a number of examples. (UWI) [de

  15. 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.

  16. Ablation characteristics and reaction mechanism of insulation materials under slag deposition condition

    Science.gov (United States)

    Guan, Yiwen; Li, Jiang; Liu, Yang

    2017-07-01

    Current understanding of the physical and chemical processes involved in the ablation of insulation materials by highly aluminized solid propellants is limited. The study on the heat transfer and ablation principle of ethylene propylene diene monomer (EPDM) materials under slag deposition condition is essential for future design or modification of large solid rocket motors (SRMs) for launch application. In this paper, the alumina liquid flow pattern and the deposition principle in full-scale SRM engines are discussed. The interaction mechanism between the alumina droplets and the wall are analyzed. Then, an experimental method was developed to simulate the insulation material ablation under slag deposition condition. Experimental study was conducted based on a laboratory-scale device. Meanwhile, from the analysis of the cross-sectional morphology and chemical composition of the charring layer after ablation, the reaction mechanism of the charring layer under deposition condition was discussed, and the main reaction equation was derived. The numerical simulation and experimental results show the following. (i) The alumina droplet flow in the deposition section of the laboratory-scale device is similar to that of a full-scale SRM. (ii) The charring layer of the EPDM insulator displays a porous tight/loose structure under high-temperature slag deposition condition. (iii) A seven-step carbothermal reduction in the alumina is derived and established under high-pressure and high-temperature environment in the SRM combustion chamber. (iv) The analysis using thermodynamic software indicates that the reaction of the alumina and charring layer initially forms Al4C3 during the operation. Then, Al element and Al2OC compound are subsequently produced with the reduction in the release of gas CO as well with continuous environmental heating.

  17. USE OF LOCAL NATURAL SILICEOUS RAW MATERIAL AND WASTES FOR PRODUCTION OF HEAT-INSULATING FOAMCONCRETE

    Directory of Open Access Journals (Sweden)

    V. U. Matsapulin

    2015-01-01

    Full Text Available The article analyzes the resource base, reserves and the use of siliceous rocks, their economic feasibility of the use for production of building materials of new generation with low-energy and other costs. Presented are the results of laboratory research and testing technology of production of insulating foam from a composition based on an aqueous solution of sodium silicate obtained from the local siliceous rocks (diatomite and the liquid alkali component - soapstock, hardener from ferrochrome slag and waste carbonate rock able to harden at a low temperature processing ( 100-110 ° C.

  18. APPLICATION OF POLYURETHANE FOAM FOR IMPACT ABSORPTION AND THERMAL INSULATION FOR RADIOACTIVE MATERIALS PACKAGINGS

    International Nuclear Information System (INIS)

    Smith, A; Glenn Abramczyk, G; Paul Blanton, P; Steve Bellamy, S; William Daugherty, W; Sharon Williamson, S

    2007-01-01

    Polyurethane foam has been widely used as an impact absorbing and thermal insulating material for large radioactive materials packages, since the 1980's. With the adoption of the regulatory crush test requirement, for smaller packages, polyurethane foam has been adopted as a replacement for cane fiberboard, because of its ability to withstand the crush test. Polyurethane foam is an engineered material whose composition is much more closely controlled than that of cane fiberboard. In addition, the properties of the foam can be controlled by controlling the density of the foam. The conditions under which the foam is formed, whether confined or unconfined have an affect on foam properties. The study reported here reviewed the application of polyurethane foam in RAM packagings and compared property values reported in the literature with published property values and test results for foam specimens taken from a prototype 9977 packaging. The study confirmed that, polyurethane foam behaves in a predictable and consistent manner and fully satisfies the functional requirements for impact absorption and thermal insulation

  19. Synthesis of one-dimensional metal-containing insulated molecular wire with versatile properties directed toward molecular electronics materials.

    Science.gov (United States)

    Masai, Hiroshi; Terao, Jun; Seki, Shu; Nakashima, Shigeto; Kiguchi, Manabu; Okoshi, Kento; Fujihara, Tetsuaki; Tsuji, Yasushi

    2014-02-05

    We report, herein, the design, synthesis, and properties of new materials directed toward molecular electronics. A transition metal-containing insulated molecular wire was synthesized through the coordination polymerization of a Ru(II) porphyrin with an insulated bridging ligand of well-defined structure. The wire displayed not only high linearity and rigidity, but also high intramolecular charge mobility. Owing to the unique properties of the coordination bond, the interconversion between the monomer and polymer states was realized under a carbon monoxide atmosphere or UV irradiation. The results demonstrated a high potential of the metal-containing insulated molecular wire for applications in molecular electronics.

  20. Aging predictions in nuclear power plants: Crosslinked polyolefin and EPR cable insulation materials

    International Nuclear Information System (INIS)

    Gillen, K.T.; Clough, R.L.

    1991-06-01

    In two earlier reports, we derived a time-temperature-dose rate superposition methodology, which, when applicable, can be used to predict cable degradation versus dose rate, temperature and exposure time. This methodology results in long-term predictive capabilities at the low dose rates appropriate to ambient nuclear power plant aging environments. The methodology was successfully applied to numerous important cable materials used in nuclear applications and the extrapolated predictions were verified by comparisons with long-term (7 to 12 year) results for similar or identical materials aged in nuclear environments. In this report, we test the methodology on three crosslinked polyolefin (CLPO) and two ethylene propylene rubber (EPR) cable insulation materials. The methodology applies to one of the CLPO materials and one of the EPR materials, allowing predictions to be made for these materials under low dose-rate, low temperature conditions. For the other materials, it is determined that, at low temperatures, a decrease in temperature at a constant radiation dose rate leads to an increase in the degradation rate for the mechanical properties. Since these results contradict the fundamental assumption underlying time-temperature-dose rate superposition, this methodology cannot be applied to such data. As indicated in the earlier reports, such anomalous results might be expected when attempting to model data taken across the crystalline melting region of semicrystalline materials. Nonetheless, the existing experimental evidence suggests that these CLPO and EPR materials have substantial aging endurance for typical reactor conditions. 28 refs., 26 figs., 3 tabs

  1. Analysis of copper contamination in transformer insulating material with nanosecond- and femtosecond-laser-induced breakdown spectroscopy

    Science.gov (United States)

    Aparna, N.; Vasa, N. J.; Sarathi, R.

    2018-06-01

    This work examines the oil-impregnated pressboard insulation of high-voltage power transformers, for the determination of copper contamination. Nanosecond- and femtosecond-laser-induced breakdown spectroscopy revealed atomic copper lines and molecular copper monoxide bands due to copper sulphide diffusion. X-ray diffraction studies also indicated the presence of CuO emission. Elemental and molecular mapping compared transformer insulating material ageing in different media—air, N2, He and vacuum.

  2. Interactions of liquid lithium with various atmospheres, concretes, and insulating materials; and filtration of lithium aerosols

    International Nuclear Information System (INIS)

    Jeppson, D.W.

    1979-06-01

    This report describes the facilities and experiments and presents test results of a program being conducted at the hanford Engineering Development Laboratory (HEDL) in support of the fusion reactor development effort. This experimental program is designed to characterize the interaction of liquid lithium with various atmospheres, concretes, and insulating materials. Lithium-atmosphere reaction tests were conducted in normal humidity air, pure nitrogen, and carbon dioxide. These tests are described and their results, such as maximum temperatures, aerosol generated, and reaction rates measured, are reported. Initial lithium temperatures for these tests ranged between 224 0 C and 843 0 C. A lithium-concrete reaction test, using 10 kg of lithium at 327 0 C, and lithium-insulating materials reaction tests, using a few grams of lithium at 350 0 C and 600 0 C, are also described and results are presented. In addition, a lithium-aerosol filter loading test was conducted to determine the mass loading capacity of a commercial high efficiency particulate air (HEPA) filter. The aerosol was characterized, and the loading-capacity-versus-pressure-buildup across the filter is reported

  3. Molecular dynamics study of water molecule diffusion in oil-paper insulation materials

    International Nuclear Information System (INIS)

    Liao Ruijin; Zhu Mengzhao; Yang Lijun; Zhou Xin; Gong Chunyan

    2011-01-01

    Moisture is an important factor that influences the safe operation of transformers. In this study, molecular dynamics was employed to investigate the diffusion behavior of water molecules in the oil-paper insulation materials of transformers. Two oil-cellulose models were built. In the first model, water molecules were initially distributed in oil, and in the second model, water molecules were distributed in cellulose. The non-bonding energies of interaction between water molecules and oil, and between water molecules and cellulose, were calculated by the Dreiding force field. The interaction energy was found to play a dominant role in influencing the equilibrium distribution of water molecules. The radial direction functions of water molecules toward oil and cellulose indicate that the hydrogen bonds between water molecules and cellulose are sufficiently strong to withstand the operating temperature of the transformer. Mean-square displacement analysis of water molecules diffusion suggests that water molecules initially distributed in oil showed anisotropic diffusion; they tended to diffuse toward cellulose. Water molecules initially distributed in cellulose diffused isotropically. This study provides a theoretical contribution for improvements in online monitoring of water in transformers, and for subsequent research on new insulation materials.

  4. Molecular dynamics study of water molecule diffusion in oil-paper insulation materials

    Energy Technology Data Exchange (ETDEWEB)

    Liao Ruijin [State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University, Chongqing 400044 (China); Zhu Mengzhao, E-mail: xiaozhupost@163.co [State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University, Chongqing 400044 (China); Yang Lijun; Zhou Xin; Gong Chunyan [State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University, Chongqing 400044 (China)

    2011-03-01

    Moisture is an important factor that influences the safe operation of transformers. In this study, molecular dynamics was employed to investigate the diffusion behavior of water molecules in the oil-paper insulation materials of transformers. Two oil-cellulose models were built. In the first model, water molecules were initially distributed in oil, and in the second model, water molecules were distributed in cellulose. The non-bonding energies of interaction between water molecules and oil, and between water molecules and cellulose, were calculated by the Dreiding force field. The interaction energy was found to play a dominant role in influencing the equilibrium distribution of water molecules. The radial direction functions of water molecules toward oil and cellulose indicate that the hydrogen bonds between water molecules and cellulose are sufficiently strong to withstand the operating temperature of the transformer. Mean-square displacement analysis of water molecules diffusion suggests that water molecules initially distributed in oil showed anisotropic diffusion; they tended to diffuse toward cellulose. Water molecules initially distributed in cellulose diffused isotropically. This study provides a theoretical contribution for improvements in online monitoring of water in transformers, and for subsequent research on new insulation materials.

  5. Measurement of the thermal conductivity of thin insulating anisotropic material with a stationary hot strip method

    International Nuclear Information System (INIS)

    Jannot, Yves; Degiovanni, Alain; Félix, Vincent; Bal, Harouna

    2011-01-01

    This paper presents a method dedicated to the thermal conductivity measurement of thin insulating anisotropic materials. The method is based on three hot-strip-type experiments in which the stationary temperature is measured at the center of the hot strip. A 3D model of the heat transfer in the system is established and simulated to determine the validity of a 2D transfer hypothesis at the center of the hot strip. A simplified 2D model is then developed leading to the definition of a geometrical factor calculable from a polynomial expression. A very simple calculation method enabling the estimation of the directional thermal conductivities from the three stationary temperature measurements and from the geometrical factor is presented. The uncertainties on each conductivity are estimated. The method is then validated by measurements on polyethylene foam and Ayous (anistropic low-density tropical wood); the estimated values of the thermal conductivities are in good agreement with the values estimated using the hot plate and the flash method. The method is finally applied on a thin super-insulating fibrous material for which no other method is able to measure the in-plane conductivity

  6. 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.

  7. Feasibility study of thermal insulation materials for core support of experimental VHTR

    International Nuclear Information System (INIS)

    Kawakami, H.; Nakanishi, T.

    1982-01-01

    Thermal insulation materials for core support of the experimental VHTR, planned by JAERI, should maintain moderate compressive strength and dimensional stability as well as low thermal conductivity at the maximum service temperature of 1100 0 C for 20 years. For selecting materials, we investigate properties of some candidates, and evaluate their feasibility. Preliminary tests, heat treatment test and compressive creep tests for 1000 hours at 900 0 C and 1000 0 C were conducted. In the preliminary tests, EG-38B (carbon baked at 1350 0 C) and Fine Finnex 600 (silicon nitride) showed acceptable physical stability. In the heat treatment tests, silicon nitride showed weight loss probably caused by thermal decomposition. Compressive creep deformation of Fine Finnex 600 was negligible under stress of 100 kg/cm 2 for 1000 hours. Heat treatment at 1200 to 1300 0 C for 50 hours improved dimensional stability of carbon at 1000 0 C

  8. Microwave heating of electric cable insulated wires before their impregnation with a hydrophobic material

    Energy Technology Data Exchange (ETDEWEB)

    Niculae, D; Mihailescu, A [Romanian Electricity Authority (Romania); Indreias, I; Martin, D [Institute of Atomic Physics, Bucharest (Romania); Margaritescu, A [ICPE Electrostatica, Bucharest, (Romania); Zlatonovici, D

    1998-12-31

    Underground insulated telecommunication cables must be impregnated with a hydrophobic material in order to prevent water penetration damage. To do so, the cable wire bundle must be heated to a temperature of 60 to 90 degrees C to ensure proper fluidity of the hydrophobic material that must fill the free spaces between the copper wires of the telephone cable. This paper described the microwave heating method of the wires before their impregnation. A cylindrical applicator was designed to perform a telephone bundle heating test. 800 W of microwave power were used on a telephone cable made up of 800 wires of 0.4 mm in diameter. A uniform heating was obtained throughout the section. Microwave heating was also found to be 53 per cent more energy efficient than hot air heating. 4 refs., 4 figs.

  9. Long-term water absorption tests for frost insulation materials taking into account frost attack

    Directory of Open Access Journals (Sweden)

    Toni A. Pakkala

    2014-01-01

    Full Text Available Water absorption of several different frost insulation materials was tested for four years. The test took into account both immersion and frost attack to materials. On the basis of the research the water absorption on XPS specimens is significantly minor compared to EPS specimens that were studied. The most significant result was that freezing of test specimens did not affect on water absorption of XPS specimens but had a major effect on water absorption of EPS specimens. With frozen EPS specimen the absorption continued increasing even after 48 months of immersion. Presumably the reason for such a behaviour is that the pore structure of EPS is not able to resist the tension caused by freezing water and therefore cracks are formed. Thus, more water absorbs inside the EPS through the cracks and it causes cracking deeper in the specimen which is why absorption increases after every freezing period.

  10. Development of Highly Repellent Silica Particles for Protection of Hemp Shiv Used as Insulation Materials.

    Science.gov (United States)

    Bourebrab, Marion A; Durand, Géraldine G; Taylor, Alan

    2017-12-21

    New bio-materials have recently gained interest for use in insulation panels in walls, but wider adoption by the building industry is hindered by their intrinsic properties. The fact that such materials are mainly composed of cellulose makes them combustible, and their hydrophilic surface presents a high water uptake, which would lead to faster biodegradation. A hydrophobic treatment with silica particles was successfully synthesised via Stöber process, characterised, and deposited on hemp shiv. The surface of hemp shiv coated several times with 45 and 120 nm particles were uniformly covered, as well as extensively water repellent. Those samples could withstand in humidity chamber without loss of their hydrophobic property and no sign of mould growth after 72 h of exposure.

  11. Development of Highly Repellent Silica Particles for Protection of Hemp Shiv Used as Insulation Materials

    Directory of Open Access Journals (Sweden)

    Marion A. Bourebrab

    2017-12-01

    Full Text Available New bio-materials have recently gained interest for use in insulation panels in walls, but wider adoption by the building industry is hindered by their intrinsic properties. The fact that such materials are mainly composed of cellulose makes them combustible, and their hydrophilic surface presents a high water uptake, which would lead to faster biodegradation. A hydrophobic treatment with silica particles was successfully synthesised via Stöber process, characterised, and deposited on hemp shiv. The surface of hemp shiv coated several times with 45 and 120 nm particles were uniformly covered, as well as extensively water repellent. Those samples could withstand in humidity chamber without loss of their hydrophobic property and no sign of mould growth after 72 h of exposure.

  12. The Microwave Noise Behaviour Of Dual Material Gate Silicon On Insulator

    Science.gov (United States)

    Jafar, N.; Soin, N.

    2009-06-01

    This work presents the noise behaviour due to the applied Dual Material Gate (DMG) on the 75 nm n-channel Silicon On Insulator (SOI) device operating in the fully depletion mode, particularly for microwave circuit design. Influences of DMG properties namely the gate length ratio (L1:L2) and gate material workfunction difference (ΔΦM) as well as structural and operational parameters which are silicon thickness (TSi) and threshold voltage (VTH) setting variation on the noise performance were carried out on simulation basis using ATLAS 2D. Results show better noise performance in DMG as compare to the standard gate structure of FD-SOI devices. Higher VTH for DMG design is recommended for minimized noise figure in line with the advantage of inverse VTH roll-off characteristics for short channel effects suppression.

  13. Characterizing material properties of cement-stabilized rammed earth to construct sustainable insulated walls

    Directory of Open Access Journals (Sweden)

    Rishi Gupta

    2014-01-01

    Full Text Available Use of local materials can reduce the hauling of construction materials over long distances, thus reducing the greenhouse gas emissions associated with transporting such materials. Use of locally available soils (earth for construction of walls has been used in many parts of the world. Owing to the thermal mass of these walls and the potential to have insulation embedded in the wall section has brought this construction material/technology at the forefront in recent years. However, the mechanical properties of the rammed earth and the parameters required for design of steel reinforced walls are not fully understood. In this paper, the author presents a case study where full-scale walls were constructed using rammed earth to understand the effect of two different types of shear detailing on the structural performance of the walls. The mechanical properties of the material essential for design such as compressive strength of the material including effect of coring on the strength, pull out strength of different rebar diameters, flexural performance and out-of-plane bending on walls was studied. These results are presented in this case study.

  14. Electrical and mechanical properties of highly elongated high density polyethylene as cryogenic insulation materials

    International Nuclear Information System (INIS)

    Yoshino, Katsumi; Park, Dae-Hee; Miyata, Kiyomi; Yamaoka, Hitoshi; Itoh, Minoru; Ichihara, Syouji.

    1989-01-01

    Electrical and mechanical properties of highly elongated high density polyethylene were investigated in the temperature range between 4.2 K and 400 K from a viewpoint of electrical insulation at low temperature and the following properties have been clarified. (1) The electrical conductivity of samples decreases with increasing draw ratio, and also decreases at cryogenic temperature. (2) Breakdown strength of highly elongated sample is similar to that of non-elongated sample. It is nearby temperature independent below 300 K but at higher temperature it falls steeply. (3) Mechanical breakdown stress and elastic modulus of high density polyethylene increase with increasing draw ratio. Their values at liquid nitrogen temperature are much higher than that at room temperature. On the other hand, strains decreases at liquid nitrogen temperature. (4) Break of the sample develops in the direction of 45deg from the direction of stress both at room temperature and at cryogenic temperature. (5) The characteristic of mechanical breakdown at liquid nitrogen temperature can be explained by a brittleness fracture process. (6) Toughness of high density polyethylene increases with increasing draw ratio until draw ratio of 5, and it decreased, and increase at higher draw ratio. However at extremely high draw ratio of 10 it again increases. These findings clearly indicate that highly elongated high density polyethylene has good electrical and mechanical properties at cryogenic temperature and can be used as the insulating materials at cryogenic temperature. (author)

  15. 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.

  16. The human impact on natural rock reserves using basalt, anorthosite, and carbonates as raw materials in insulation products

    DEFF Research Database (Denmark)

    Dahl, Tais Wittchen; Clausen, Anders U.; Hansen, Peter B.

    2011-01-01

    lithosphere or subducted with oceanic crust and recycled through the mantle by plate tectonics. Insulation products have a chemical composition similar to average crustal rocks and participate in the natural rock cycle. However, these products need not accumulate in nature, inasmuch as old insulation......Typical crustal rocks such as basalt, limestone, and anorthosite are used in stone wool insulation products. The raw materials for stone wool production are not specific to any rare mineral source but depend upon the mixture of materials having the correct chemical composition, exemplified by 40 wt......% basalt, 20 wt% anorthosite, and 40 wt% cement-bonded renewable materials. This study provides an overview of the natural cycle of these resources, including their abundances in nature, and sets the consumption by the stone wool industry and other human activities in perspective. Basalt, anorthosite...

  17. Novel Application of Glass Fibers Recovered From Waste Printed Circuit Boards as Sound and Thermal Insulation Material

    Science.gov (United States)

    Sun, Zhixing; Shen, Zhigang; Ma, Shulin; Zhang, Xiaojing

    2013-10-01

    The aim of this study is to investigate the feasibility of using glass fibers, a recycled material from waste printed circuit boards (WPCB), as sound absorption and thermal insulation material. Glass fibers were obtained through a fluidized-bed recycling process. Acoustic properties of the recovered glass fibers (RGF) were measured and compared with some commercial sound absorbing materials, such as expanded perlite (EP), expanded vermiculite (EV), and commercial glass fiber. Results show that RGF have good sound absorption ability over the whole tested frequency range (100-6400 Hz). The average sound absorption coefficient of RGF is 0.86, which is prior to those of EP (0.81) and EV (0.73). Noise reduction coefficient analysis indicates that the absorption ability of RGF can meet the requirement of II rating for sound absorbing material according to national standard. The thermal insulation results show that RGF has a fair low thermal conductivity (0.046 W/m K), which is comparable to those of some insulation materials (i.e., EV, EP, and rock wool). Besides, an empirical dependence of thermal conductivity on material temperature was determined for RGF. All the results showed that the reuse of RGF for sound and thermal insulation material provided a promising way for recycling WPCB and obtaining high beneficial products.

  18. Long-term radiation effects on commercial cable-insulating materials irradiated at CERN

    International Nuclear Information System (INIS)

    Maier, P.; Stolarz, A.

    1983-01-01

    Long-term irradiation damage tests have been carried out on a variety of flexible cable-insulating materials offered to CERN by different European cable manufacturers. Tensile test specimens were exposed for a maximum of three years in high-level radiation areas of the Super Proton Synchrotron (SPS) and for comparison at high dose rates in a nuclear reactor. The degradation of mechanical properties after irradiation in air depends not only on the total absorbed dose, but also on the dose rate for most of these polymer compounds. These dose-rate effects vary between material types and for different compounds. The results presented here illustrate the difference in radiation damage between short-term and long-term irradiation conditions in a typical service application for the various materials tested. They also allow safety factors to be estimated for the extrapolation of the limiting exposure in service from accelerated material tests in the range of dose rates covered. A discussion of the available models of the dose-rate effects results in a conservative estimate for extrapolation to low dose rates from measured values at intermediate dose rates of the order of 0.1 Gy/s. Based on short-term irradiation tests only, the safety factors to be applied depend on the end-point criterion used, and may vary between 1 and 10 for the range of dose rates and materials considered here. (orig.)

  19. Experimental performance evaluation of solid concrete and dry insulation materials for passive buildings in hot and humid climatic conditions

    International Nuclear Information System (INIS)

    Rehman, Hassam Ur

    2017-01-01

    Highlights: • Experimental investigation of building insulation materials in UAE from 2012–2014. • Four same calorimeters with different south walls were built in open air laboratory. • Heat flux was reduced by 22–75% in steady state analysis during summer by insulation. • Hence, energy consumption for cooling was reduced by an average 7.6–25.3%. • Heat flow was steady in free floating analysis in winter through insulated walls. - Abstract: It is known that enhancement of building energy efficiency can help in reducing energy consumption. The use of the solar insulating materials are the most efficient and cost effective passive methods for reducing the cooling requirements of the buildings. Apart from theoretical studies, no detailed experimental studies were performed in the UAE on energy savings by using solar insulation materials on buildings. Four (3 m × 3 m × 3 m) solar calorimeters were built in RAK, UAE in order to perform an open air outdoor test for energy savings obtained with solar insulating materials. The design is aimed to determine the heat flux reduction and the energy savings achieved with and without different solar insulating materials, mounted at the south wall of solar calorimeters with similar indoor and ambient conditions. Experimental results are discussed to evaluate the thermal performance during high temperature conditions in summer’s period when cooling demand of the building is at its peak and also in winters when there is no cooling demand. The test is from 2012 to 2014. The controlled-temperature experimental study at a set point of 24 °C showed that if the standard building material, i.e. solid concrete, is retrofitted with polyisocyanurate (PIR) and reflective coatings or completely replaced with energy-efficient dry insulation material walls such as exterior insulation finishing system (EIFS), energy savings up to an average of 7.6–25.3% can be achieved. This is due to the reduction of heat flux by an

  20. Defect Detection of Adhesive Layer of Thermal Insulation Materials Based on Improved Particle Swarm Optimization of ECT.

    Science.gov (United States)

    Wen, Yintang; Jia, Yao; Zhang, Yuyan; Luo, Xiaoyuan; Wang, Hongrui

    2017-10-25

    This paper studies the defect detection problem of adhesive layer of thermal insulation materials. A novel detection method based on an improved particle swarm optimization (PSO) algorithm of Electrical Capacitance Tomography (ECT) is presented. Firstly, a least squares support vector machine is applied for data processing of measured capacitance values. Then, the improved PSO algorithm is proposed and applied for image reconstruction. Finally, some experiments are provided to verify the effectiveness of the proposed method in defect detection for adhesive layer of thermal insulation materials. The performance comparisons demonstrate that the proposed method has higher precision by comparing with traditional ECT algorithms.

  1. Improving Performance of Cold-Chain Insulated Container with Phase Change Material: An Experimental Investigation

    Directory of Open Access Journals (Sweden)

    Li Huang

    2017-12-01

    Full Text Available The cold-chain transportation is an important means to ensure the drug and food safety. An cold-chain insulated container incorporating with Phase Change Material (PCM has been developed for a temperature-controlled transportation in the range of 2~8 °C. The container configuration and different preconditioning methods have been determined to realize a 72-h transportation under extremely high, extremely low, and alternating temperature conditions. The experimental results showed that the temperature-controlled time was extended from 1 h to more than 80 h and the internal temperature maintained at 4~5 °C by using a PCM with a melting/freezing point of 5 °C, while the container presented a subcooling effect in a range of −1~2 °C when using water as PCM. The experimental values of the temperature-controlled time agreed well with the theoretical values.

  2. High insulation foam glass material from waste cathode ray tube panel glass

    DEFF Research Database (Denmark)

    König, Jakob; Petersen, Rasmus Rosenlund; Yue, Yuanzheng

    . In general CRT consists of two types of glasses: barium/strontium containing glass (panel glass) and lead containing glass (funnel and panel glass). In this work we present the possibility to produce high performance insulation material from the recycled lead-free glass. We studied the influence of foaming...... between 750 and 850°C. We investigated the influence of milling time, particle size, foaming and oxidizing agent concentrations, temperature and time on the foaming process, foam density, foam porosity and homogeneity. Only moderate foaming was observed in carbon containing samples, while the addition...... of the oxidizing agent greatly improved the foaming quality. The results showed that the amount of oxygen available from the glass is not sufficient to combust all of the added carbon, therefore, additional oxygen was supplied via manganese reduction. In general, a minimum in the foam glass density was observed...

  3. Metal-Insulator Transition Driven by Vacancy Ordering in GeSbTe Phase Change Materials.

    Science.gov (United States)

    Bragaglia, Valeria; Arciprete, Fabrizio; Zhang, Wei; Mio, Antonio Massimiliano; Zallo, Eugenio; Perumal, Karthick; Giussani, Alessandro; Cecchi, Stefano; Boschker, Jos Emiel; Riechert, Henning; Privitera, Stefania; Rimini, Emanuele; Mazzarello, Riccardo; Calarco, Raffaella

    2016-04-01

    Phase Change Materials (PCMs) are unique compounds employed in non-volatile random access memory thanks to the rapid and reversible transformation between the amorphous and crystalline state that display large differences in electrical and optical properties. In addition to the amorphous-to-crystalline transition, experimental results on polycrystalline GeSbTe alloys (GST) films evidenced a Metal-Insulator Transition (MIT) attributed to disorder in the crystalline phase. Here we report on a fundamental advance in the fabrication of GST with out-of-plane stacking of ordered vacancy layers by means of three distinct methods: Molecular Beam Epitaxy, thermal annealing and application of femtosecond laser pulses. We assess the degree of vacancy ordering and explicitly correlate it with the MIT. We further tune the ordering in a controlled fashion attaining a large range of resistivity. Employing ordered GST might allow the realization of cells with larger programming windows.

  4. 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.

  5. Practical reasons for investigating ion transport in high temperature insulating materials

    International Nuclear Information System (INIS)

    Sonder, E.

    1976-01-01

    Practical problems encountered in a number of advanced technology appliations, particularly those related to energy conversion, are discussed. Refractory ionic compounds which are abundant and of high melting point are listed, and technological problems are discussed in terms of specific materials problems. The argument is made that basic information concerning transport properties in refractory compounds is lacking to such an extent that it is difficult to design and assess advanced energy generation systems. Technology applications include: a) ceramic nuclear fuels for high temperature fission reactors, b) high temperature gas turbine blades, c) insulators in controlled thermonuclear reactors, and d) magnetohydrodynamic generators. Some of the difficulties inherent in making transport property measurements at high temperatures are also listed

  6. MODAL ANALYSIS OF REAL TIMBER FRAME HOUSES WITH DIFFERENT INSULATION MATERIALS

    Directory of Open Access Journals (Sweden)

    Marcin Szczepański

    2016-09-01

    Full Text Available The aim of this article is to present the results of a numerical modal analysis of two actual structures of timber frame buildings and the different behaviour due to the used insulation material. One model of the timber structure was filled with mineral wool, while the other with polyurethane foam. During the modal analysis, eigenvalues for both models have been determined. The results of the analysis clearly show the increase of stiffness and damping properties of skeletal constructions achieved by the use of polyurethane foam as the skeleton filling. The numerical model was based on prior experimental test on real scale single frame elements, therefore the result can be assumed to be adequate.

  7. Evaluation of the high-voltage high-frequency transformer insulating materials for satellites

    International Nuclear Information System (INIS)

    Kurita, Hiroshi; Hasegawa, Taketoshi; Hirasawa, Eiichi; Gonai, Toshio; Ohsuga, Hiroyuki.

    1987-01-01

    Environment resistance evaluation was made of the insulating materials of impregnated injection type for high-voltage high-frequency transformers mounted in satellites. (1) The stress occurring in the impregnated injection type resin is small in silicon resin and urethane resin and large in epoxy resin. (2) The dielectric characteristic at high frequency is good in silicone resin. In epoxy resin, when the transformer is operated at high temperature, its thermal runaway may take place. (3) The radiation deterioration at 1 Mrad - 10 Mrad is slight in urethane resin. (4) The degassing is not good in silicone resin. (5) The adhesive power is good in urethane resin. (6) From the above results, in silicone resin there is problem in degassing and adhesive power. In epoxy resin there is problem in stress and dielectric characteristic. (Mori, K.)

  8. Metal - Insulator Transition Driven by Vacancy Ordering in GeSbTe Phase Change Materials

    Science.gov (United States)

    Bragaglia, Valeria; Arciprete, Fabrizio; Zhang, Wei; Mio, Antonio Massimiliano; Zallo, Eugenio; Perumal, Karthick; Giussani, Alessandro; Cecchi, Stefano; Boschker, Jos Emiel; Riechert, Henning; Privitera, Stefania; Rimini, Emanuele; Mazzarello, Riccardo; Calarco, Raffaella

    2016-04-01

    Phase Change Materials (PCMs) are unique compounds employed in non-volatile random access memory thanks to the rapid and reversible transformation between the amorphous and crystalline state that display large differences in electrical and optical properties. In addition to the amorphous-to-crystalline transition, experimental results on polycrystalline GeSbTe alloys (GST) films evidenced a Metal-Insulator Transition (MIT) attributed to disorder in the crystalline phase. Here we report on a fundamental advance in the fabrication of GST with out-of-plane stacking of ordered vacancy layers by means of three distinct methods: Molecular Beam Epitaxy, thermal annealing and application of femtosecond laser pulses. We assess the degree of vacancy ordering and explicitly correlate it with the MIT. We further tune the ordering in a controlled fashion attaining a large range of resistivity. Employing ordered GST might allow the realization of cells with larger programming windows.

  9. Analysis of the optical and thermal properties of transparent insulating materials containing gas bubbles

    International Nuclear Information System (INIS)

    Cai, Qilin; Ye, Hong; Lin, Qizhao

    2016-01-01

    Highlights: • Transparent insulating medium containing gas bubbles was proposed. • Radiative transfer and thermal conduction models were constructed. • Bulk transmittance increases first and then decreases with the bubble number. • Effective thermal conductivity decreases with increasing filling ratio. • High filling ratio with large bubbles is preferred for good performance. - Abstract: As a medium of low absorption and low thermal conduction, introducing gas bubbles into semitransparent mediums, such as glass and polycarbonate (PC), may simultaneously improve their light transmission and thermal insulation performances. However, gas bubbles can also enhance light scattering, which is in competition with the effect of the absorption decrease. Moreover, the balance between the visible light transmittance and the effective thermal conductivity should also be considered in the material design. Therefore, a radiative transfer model and the Maxwell–Eucken model for such material were employed to analyze the optical and thermal performances, respectively. The results demonstrate that the transmittance increases when the bubble radius (r) increases with a fixed volume fraction of the gas bubbles (f_v) due to the increased scattering intensity. In addition, the effective thermal conductivity always decreases with increasing f_v. Thus, to achieve both good optical and thermal performances, high f_v with large r is preferred. When f_v=0.5, the transmittance can be kept larger than 50% as long as r ≥ 0.7 mm. To elucidate the application performance, the heat transfer of a freezer adopting the glass or PC with gas bubbles as a cover was analyzed and the energy saving can be nearly 10%.

  10. Lessons learned from the development and manufacture of ceramic reusable surface insulation materials for the space shuttle orbiters

    Science.gov (United States)

    Banas, R. P.; Elgin, D. R.; Cordia, E. R.; Nickel, K. N.; Gzowski, E. R.; Aguiler, L.

    1983-01-01

    Three ceramic, reusable surface insulation materials and two borosilicate glass coatings were used in the fabrication of tiles for the Space Shuttle orbiters. Approximately 77,000 tiles were made from these materials for the first three orbiters, Columbia, Challenger, and Discovery. Lessons learned in the development, scale up to production and manufacturing phases of these materials will benefit future production of ceramic reusable surface insulation materials. Processing of raw materials into tile blanks and coating slurries; programming and machining of tiles using numerical controlled milling machines; preparing and spraying tiles with the two coatings; and controlling material shrinkage during the high temperature (2100-2275 F) coating glazing cycles are among the topics discussed.

  11. Stress-Dependent Voltage Offsets From Polymer Insulators Used in Rock Mechanics and Material Testing

    Science.gov (United States)

    Carlson, G. G.; Dahlgren, Robert; Gray, Amber; Vanderbilt, V. C.; Freund, F.; Johnston, M. J.; Dunson, C.

    2013-01-01

    Dielectric insulators are used in a variety of laboratory settings when performing experiments in rock mechanics, petrology, and electromagnetic studies of rocks in the fields of geophysics,material science, and civil engineering. These components may be used to electrically isolate geological samples from the experimental equipment, to perform a mechanical compliance function between brittle samples and the loading equipment, to match ultrasonic transducers, or perform other functions. In manyexperimental configurations the insulators bear the full brunt of force applied to the sample but do not need to withstand high voltages, therefore the insulators are often thin sheets of mechanically tough polymers. From an instrument perspective, transduction from various types of mechanical perturbation has beenqualitatively compared for a number of polymers [1, 2] and these error sources are readily apparent duringhigh-impedance measurements if not mitigated. However even when following best practices, a force dependent voltage signal still remains and its behavior is explored in this presentation. In this experimenttwo thin sheets (0.25 mm) of high-density polyethylene (HDPE) were set up in a stack, held alternatelybetween three aluminum bars; this stack was placed on the platen of a 60T capacity hydraulic testingmachine. The surface area, A, over which the force is applied to the PE sheets in this sandwich is roughly 40 square cm, each sheet forming a parallel-plate capacitor having roughly 320 pF [3], assuming therelative dielectric permittivity of PE is approximately 2.3. The outer two aluminum bars were connected to the LO input ofthe electrometer and the central aluminum bar was connected to the HI input of a Keithley model 617 electrometer. Once the stack is mechanically well-seated with no air gaps, the voltage offset is observed tobe a linear function of the baseline voltage for a given change in applied force. For a periodically appliedforce of 66.7 kN the

  12. Device Performance of the Mott InsulatorDevice Performance of the Mott Insulator LaVO3 as a Photovoltaic Material

    KAUST Repository

    Wang, Lingfei

    2015-06-22

    Searching for solar-absorbing materials containing earth-abundant elements with chemical stability is of critical importance for advancing photovoltaic technologies. Mott insulators have been theoretically proposed as potential photovoltaic materials. In this paper, we evaluate their performance in solar cells by exploring the photovoltaic properties of Mott insulator LaVO3 (LVO). LVO films show an indirect band gap of 1.08 eV as well as strong light absorption over a wide wavelength range in the solar spectrum. First-principles calculations on the band structure of LVO further reveal that the d−d transitions within the upper and lower Mott-Hubbard bands and p−d transitions between the O 2p and V 3d band contribute to the absorption in visible and ultraviolet ranges, respectively. Transport measurements indicate strong carrier trapping and the formation of polarons in LVO. To utilize the strong light absorption of LVO and to overcome its poor carrier transport, we incorporate it as a light absorber in solar cells in conjunction with carrier transporters and evaluate its device performance. Our complementary experimental and theoretical results on such prototypical solar cells made of Mott-Hubbard transition-metal oxides pave the road for developing light-absorbing materials and photovoltaic devices based on strongly correlated electrons.

  13. Development of advanced material composites for use as internal insulation for LH2 tanks (gas layer concept)

    Science.gov (United States)

    Gille, J. P.

    1972-01-01

    A program is described that was conducted to develop an internal insulation system for potential application to the liquid hydrogen tanks of a reusable booster, where the tanks would be subjected to repeated high temperatures. The design of the internal insulation is based on a unique gas layer concept, in which capillary or surface tension effects are used to maintain a stable gas layer, within a cellular core structure, between the tank wall and the contained liquid hydrogen. Specific objectives were to select materials for insulation systems that would be compatible with wall temperatures of 350 F and 650 F during reentry into the earth's atmosphere, and to fabricate and test insulation systems under conditions simulating the operating environment. A materials test program was conducted to evaluate the properties of candidate materials at elevated temperatures and at the temperature of liquid hydrogen, and to determine the compatibility of the materials with a hydrogen atmosphere at the appropriate elevated temperature. The materials that were finally selected included Kapton polyimide films, silicone adhesives, fiber glass batting, and in the case of the 350 F system, Teflon film.

  14. Thermal insulating panel

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, J.T.

    1985-09-11

    A panel of thermal insulation material has at least one main portion which comprises a dry particulate insulation material compressed within a porous envelope so that it is rigid or substantially rigid and at least one auxiliary portion which is secured to and extends along at least one of the edges of the main portions. The auxiliary portions comprise a substantially uncompressed dry particulate insulation material contained within an envelope. The insulation material of the auxiliary portion may be the same as or may be different from the insulation material of the main portion. The envelope of the auxiliary portion may be made of a porous or a non-porous material. (author).

  15. 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...

  16. Diffusion and solubility of oxygen in γ-ray irradiated polymer insulation materials

    International Nuclear Information System (INIS)

    Seguchi, Tadao; Yamamoto, Yasuaki.

    1986-03-01

    The effects of 60 Co γ-rays irradiation on diffusion and solubility of oxygen in polymer materials for electric cable insulation materials were investigated. The polymers were polyethylene, ethylene-propylene rubber, chlorinated polyethylene, chlorosulphonated polyethylene, and chloroprene rubber. They were pure grade and several types of formulation grade. The sheets of these polymers were irradiated up to 5 - 200 Mrad under vacuum or in oxygen under pressure of 3 - 15 atm at room temperature or at 70 deg C. By a method of gas desorption, the diffusion coefficient (D) and solubility coefficient (S) of oxygen or argon in polymer materials were determined at various temperatures of 10 - 80 deg C. The D and S decreased with increase of dose, and the decrease by irradiation with oxidation was more remarkable than that by irradiation without oxidation. However, the decreases of D and S by irradiation were reduced by the formulation of polymers. The additives in formulated polymers would reduce the reactions of crosslinking or oxidation by γ-ray irradiation. The activation energy of D was scarcely changed by irradiations with and without oxidation. (author)

  17. Accelerated thermal and radiation-oxidation combined degradation of electric cable insulation materials

    International Nuclear Information System (INIS)

    Yagi, Toshiaki; Seguchi, Tadao; Yoshida, Kenzo

    1986-03-01

    For the development of accelerated testing methodology to estimate the life time of electric cable, which is installed in radiation field such as a nuclear reactor containment vessel, radiation and thermal combined degradation of cable insulation and jacketing materials was studied. The materials were two types of formulated polyethylene, ethylene-propylene rubber, Hypalon, and Neoprene. With Co-60 γ-rays the materials were irradiated up to 0.5 MGy under vacuum and in oxygen under pressure, then exposed to thermal aging at elevated temperature in oxygen. The degradation was investigated by the tensile test, gelfraction, and swelling measurements. The thermal degradation rate for each sample increases with increase of oxygen concentration, i.e. oxygen pressure, during the aging, and tends to saturate above 0.2 MPa of oxygen pressure. Then, the effects of irradiation and the temperature on the thermal degradation rate were investigated at the oxygen pressure of 0.2 MPa in the temperature range from 110 deg C to 150 deg C. For all of samples irradiated in oxygen, the following thermal degradation rate was accelerated by several times comparing with unirradiated samples, while the rate of thermal degradation for the sample except Neoprene irradiated under vacuum was nearly equal to that of unirradiated one. By the analysis of thermal degradation rate against temperature using Arrhenius equation, it was found that the activation energy tends to decrease for the samples irradiated in oxidation condition. (author)

  18. Spin and Charge Transport in 2D Materials and Magnetic Insulator/Metal Heterostructures

    Science.gov (United States)

    Amamou, Walid

    Spintronic devices are very promising for future information storage, logic operations and computation and have the potential to replace current CMOS technology approaching the scaling limit. In particular, the generation and manipulation of spin current enables the integration of storage and logic within the same circuit for more powerful computing architectures. In this thesis, we examine the manipulation of spins in 2D materials such as graphene and metal/magnetic insulator heterostructures. In particular, we investigate the feasibility for achieving magnetization switching of a nanomagnet using graphene as a nonmagnetic channel material for All Spin Logic Device applications. Using in-situ MBE deposition of nanomagnet on graphene spin valve, we demonstrate the presence of an interfacial spin dephasing at the interface between the graphene and the nanomagnet. By introducing a Cu spacer between the nanomagnet and graphene, we demonstrate that this interfacial effect is related to an exchange interaction between the spin current and the disordered magnetic moment of the nanomagnet in the first monolayer. In addition to the newly discovered interfacial spin relaxation effect, the extracted contact resistance area product of the nanomagnet/graphene interface is relatively high on the order of 1Omicrom2. In practice, reducing the contact resistance will be as important as eliminating the interfacial relaxation in order to achieve magnetization switching. Furthermore, we examine spin manipulation in a nonmagnetic Pt using an internal magnetic exchange field produced by the adjacent magnetic insulator CoFe2O4 grown by MBE. Here, we report the observation of a strong magnetic proximity effect of Pt deposited on top of a perpendicular magnetic anisotropy (PMA) inverse spinel material Cobalt Ferrite (CFO, CoFe 2O4). The CFO was grown by MBE and its magnetization was characterized by Vibrating Sample Magnetometry (VSM) demonstrating the strong out of plane magnetic

  19. Numerical simulation of the insulation material transport to a PWR core under loss of coolant accident conditions

    International Nuclear Information System (INIS)

    Höhne, Thomas; Grahn, Alexander; Kliem, Sören; Rohde, Ulrich; Weiss, Frank-Peter

    2013-01-01

    Highlights: ► Detailed results of a numerical simulation of the insulation material transport to a PWR core are shown. ► The spacer grid is modeled as a strainer which completely retains the insulation material carried by coolant. ► The CFD calculations showed that the fibers at the upper spacer grid plane are not uniformly distributed. ► Furthermore the pressure loss does not exceed a critical limit. ► The PWR core coolablity can be guaranteed all the time during the transient. -- Abstract: In 1992, strainers on the suction side of the ECCS pumps in Barsebäck NPP Unit 2 became partially clogged with mineral wool because after a safety valve opened the steam impinged on thermally insulated equipment and released mineral wool. This event pointed out that strainer clogging is an issue in the course of a loss-of-coolant accident. Modifications of the insulation material, the strainer area and mesh size were carried out in most of the German NPPs. Moreover, back flushing procedures to remove the mineral wool from the strainers and differential pressure measurements were implemented to assure the performance of emergency core cooling during the containment sump recirculation mode. Nevertheless, it cannot be completely ruled out, that a limited amount of small fractions of the insulation material is transported into the RPV. During a postulated cold leg LOCA with hot leg ECC injection, the fibers enter the upper plenum and can accumulate at the fuel element spacer grids, preferably at the uppermost grid level. This effect might affect the ECC flow into the core and could result in degradation of core cooling. It was the aim of the numerical simulations presented to study where and how many mineral wool fibers are deposited at the upper spacer grid. The 3D, time dependent, multi-phase flow problem was modeled applying the CFD code ANSYS CFX. The CFD calculation does not yet include steam production in the core and also does not include re-suspension of the

  20. 2006/07 Field Testing of Cellulose Fiber Insulation Enhanced with Phase Change Material

    Energy Technology Data Exchange (ETDEWEB)

    Kosny, Jan [ORNL; Yarbrough, David W [ORNL; Miller, William A [ORNL; Petrie, Thomas [ORNL; Childs, Phillip W [ORNL; Syed, Azam M [ORNL

    2008-12-01

    Most recent improvements in building envelope technologies suggest that in the near future, residences will be routinely constructed to operate with very low heating and cooling loads. In that light, the application of novel building materials containing active thermal components (e.g., phase change materials [PCMs,] sub-venting, radiant barriers, and integrated hydronic systems) is like a final step in achieving relatively significant heating and cooling energy savings from technological improvements in the building envelope. It is expected that optimized building envelope designs using PCMs for energy storage can effectively bring notable savings in energy consumption and reductions in peak hour power loads. During 2006/07, a research team at Oak Ridge National Laboratory (ORNL) performed a series of laboratory and field tests of several wall and roof assemblies using PCM-enhanced cellulose insulation. This report summarizes the test results from the perspective of energy performance. The ORNL team is working on both inorganic and organic PCMs; this report discusses only paraffinic PCMs. A limited economical analysis also is presented. PCMs have been tested as a thermal mass component in buildings for at least 40 years. Most of the research studies found that PCMs enhanced building energy performance. In the case of the application of organic PCMs, problems such as high initial cost and PCM leaking (surface sweating) have hampered widespread adoption. Paraffinic hydrocarbon PCMs generally performed well, with the exception that they increased the flammability of the building envelope.

  1. PREFACE: 12th Europhysical Conference on Defects in Insulating Materials (EURODIM 2014)

    Science.gov (United States)

    Alfredsson, M. L.; Chadwick, A. V.; Jackson, R. A.; McCabe, E. E.

    2015-04-01

    The 12th Europhysical Conference on Defects in Insulating Materials (EURODIM14) was held at the University of Kent, UK, from 13-18 July 2014. It was attended by about 120 delegates from around the world, and featured 56 oral presentations and 77 posters. EURODIM14 followed other conferences in the series, held in Pecs (2010), Milan (2006) and Wroclaw (2002), as well as the related ICDIM conferences held in Santa Fe (2012), Aracaju (2008) and Riga (2004). These conferences all have the aim of bringing together scientists to discuss the chemistry and physics of defects in solids, and their role in determining material properties. We would like to thank the International Advisory Committee for suggesting invited speakers, and the Local and Programme Committee for their hard work in planning and running the conference. Finally we would like to thank the authors and referees for their contributions to the proceedings. M L Alfredsson (Conference Chair) A V Chadwick R A Jackson E E McCabe

  2. 12th Europhysical Conference on Defects in Insulating Materials (EURODIM 2014)

    International Nuclear Information System (INIS)

    Alfredsson, M L; Chadwick, A V; Jackson, R A; McCabe, E E

    2015-01-01

    The 12th Europhysical Conference on Defects in Insulating Materials (EURODIM14) was held at the University of Kent, UK, from 13-18 July 2014. It was attended by about 120 delegates from around the world, and featured 56 oral presentations and 77 posters. EURODIM14 followed other conferences in the series, held in Pecs (2010), Milan (2006) and Wroclaw (2002), as well as the related ICDIM conferences held in Santa Fe (2012), Aracaju (2008) and Riga (2004). These conferences all have the aim of bringing together scientists to discuss the chemistry and physics of defects in solids, and their role in determining material properties. We would like to thank the International Advisory Committee for suggesting invited speakers, and the Local and Programme Committee for their hard work in planning and running the conference. Finally we would like to thank the authors and referees for their contributions to the proceedings. M L Alfredsson (Conference Chair) A V Chadwick R A Jackson E E McCabe (preface)

  3. Building materials and systems with vacuum insulation panels for external walls; Bauelemente und Systeme mit VIP fuer Aussenwandkonstruktionen - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Binz, A; Steinke, G

    2007-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) takes a look at materials and systems using vacuum insulation panels (VIP) for the construction of external walls. The aim of this research project was the development, practical use and market introduction of VIP systems that take account of the special properties of VIP. Along with partners in industry, applications involving external and internal insulation were examined. The need for protecting the vacuum panels against mechanical damage is stressed. The specific needs for the protection of external and internal applications are discussed. The dynamic developments in this relatively new area are commented on. Various mounting systems are examined and commented on. The thermal properties of such insulation systems and applications are noted and commented on.

  4. Thermal insulation

    International Nuclear Information System (INIS)

    Durston, J.G.; Birch, W.; Facer, R.I.; Stuart, R.A.

    1977-01-01

    Reference is made to liquid metal cooled nuclear reactors. In the arrangement described the reactor vessel is clad with thermal insulation comprising a layer of insulating blocks spaced from the wall and from each other; each block is rigidly secured to the wall, and the interspaces are substantially closed against convectional flow of liquid by resilient closure members. A membrane covering is provided for the layer of blocks, with venting means to allow liquid from the reactor vessel to penetrate between the covering and the layer of blocks. The membrane covering may comprise a stainless steel sheet ribbed in orthogonal pattern to give flexibility for the accommodation of thermal strain. The insulating blocks may be comprised of stainless steel or cellular or porous material and may be hollow shells containing ceramic material or gas fillings. (U.K.)

  5. 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

  6. Lightweight, Cost Effective LOX Compatible Aerogel Insulation Material for Cryogenic Fluid Transfer Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Energy-efficient cryogenic insulation is an imperative requirement for the future of space travel. In order to advance the space program, NASA must find cost...

  7. Development of advanced materials composites for use as insulations for LH2 tanks

    Science.gov (United States)

    Lemons, C. R.; Salmassy, O. K.

    1973-01-01

    A study of thread-reinforced polyurethane foam and glass fabric liner, serving as internally bonded insulation for space shuttle LH2 tanks, is reported. Emphasis was placed on an insulation system capable of reentry and multiple reuse in the shuttle environment. The optimized manufacturing parameters associated with each element of the composite are established and the results, showing successful completion of subscale system evaluation tests using the shuttle flight environmental requirements, are given.

  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

    2016-04-07

    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.

  9. PREFACE 11th Europhysical Conference on Defects in Insulating Materials (EURODIM 2010)

    Science.gov (United States)

    Kovács, László; Corradi, Gábor

    2010-11-01

    The Europhysical Conference on Defects in Insulating Materials, organized in the period 12-16 July 2010 in Pécs, Hungary by the Research Institute for Solid State Physics and Optics, Budapest and the Institute of Physics of the University of Pécs, was the 11th European conference in the alternate series of EURODIM and ICDIM. The first meeting in Argonne, USA in 1956 was dedicated to the field of color centers in alkali halide crystals. Since then the topic has been gradually extended to the real structure of oxides, halides, nitrides and other more complex insulators, and also to less ordered materials like glasses, ceramics and low-dimensional systems, as well as applications e.g. in radiology, non-linear optics, photonics and electronics. Recently the field covered includes the research and technology of defect-related phenomena in crystalline and amorphous wide band-gap bulk, layered and nano-materials. More than 200 colleagues from 31 countries in Europe, Asia, Africa and the Americas have participated in the conference. The program contained in addition to seven invited and three keynote talks 67 further oral presentations as well as some 200 poster contributions. The city of Pécs, a pearl of the Southern Danubia region, was proud of hosting the conference as one of the 2010 European Capitals of Culture, this status crowning a long urban history dating back to paleochristian times in the Roman province Pannonia. On behalf of the Organizing Committee signature László Kovács Conference Chair Conference Chair László Kovács Crystal Physics Department Research Institute for Solid State Physics and Optics Budapest, Hungary e-mail: eurodim2010@optics.szfki.kfki.hu Program Committee Gábor Corradi (Hungary) István Földvári (Hungary) Rob A. Jackson (UK) László Kovács (Hungary) Martin Nikl (Czech Republic) Anna Vedda (Italy) Andrea Watterich (Hungary) International Advisory Committee M.G. Blanchin (France)A. Lushchik (Estonia) F. Bridges (USA

  10. Analysis of insulation material deterioration under the LOCA simulated environment on the basis of reaction kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Sohei; Kusama, Yasuo; Ito, Masayuki; Yagi, Toshiaki; Yoshikawa, Masato (Japan Atomic Energy Research Inst., Takasaki, Gunma. Takasaki Radiation Chemistry Research Establishment)

    1982-12-01

    In the type test of the electric cables installed in reactor containment vessels, it is considerably difficult to perform the testing over a year once in a while to simulate the accidental environment containing radiation and high temperature steam. Two requirements which seem to be more realistic as compared with the above mentioned testing method are inconsistent with each other. To solve this problem, a general rule of deterioration or the expression by an equation is necessary, which enables the extrapolation to show that a short term testing stands on the safety side. The authors have tried to numerically analyze the change of mechanical characteristics of ethylene-propylene rubber (EPR) and Hypalon which are, important as the materials for PH cables (fire-retardant, EP rubber-insulated, chlorosulfonated polyethylene-sheathed cable), in a complex environment of radiation, steam and chemical spray simulating PWR LOCA conditions. In this report, a method is proposed to analyze and estimate the properties by the regression analysis technique on the basis of reaction kinetics, and the analyzed results are described in the order of experiment, analysis method and the results and consideration. The deterioration of the elongation P = e/esub(o) of EPR and Hypalon in the above described complex environment can be represented by the equation - dP/dt = KPsup(n). The exponent n varied in the cases when air is contained or not in that environment, suggesting that the different reactions are dominant in both conditions, respectively. For EPR, n was close to 2 if air was not contained and close to 1 if air was contained in the system.

  11. Translucent insulating building envelope

    DEFF Research Database (Denmark)

    Rahbek, Jens Eg

    1997-01-01

    A new type of translucent insulating material has been tested. This material is made of Celulose-Acetat and have a honey-comb structure. The material has a high solar transmittance and is highly insulating. The material is relatively cheap to produce. Danish Title: Translucent isolerende klimaskærm....

  12. Quantum and Classical Optics of Plasmonic Systems: 3D/2D Materials and Photonic Topological Insulators

    Science.gov (United States)

    Hassani Gangaraj, Seyyed Ali

    analysis of the Green's function for the surface plasmonic wave contribution of the Sommerfeld integral. The Sommerfeld integral form of the Green's function can be time-consuming to evaluate, and here, it has been shown that for the surface waves, this integral can be evaluated efficiently as a mixture of continuous and discrete spectrums associated to the radiation of the source into the ambient space and energy coupled to the SPPs. Graphene strip arrays provide directive surface waves in the low THz regime, and unperturbed black phosphorus provides a similar response for higher frequency ranges. All plasmonic devices are impacted by SPP diffraction at surface defects and discontinuities. In particular, for reciprocal materials a surface defect/discontinuity can both scatter a forward mode into a backward mode (and vice versa) and cause significant radiation/diffraction of the SPP. The presence of a backward state comes from time reversal (TR) symmetry; when broken, a backward state may be absent, and reflection at a discontinuity can be suppressed. As a result, surface energy becomes unidirectional and follows the contour of the interface. This type of system can be broadly classified as a photonic topological insulators (PTIs). The properties of PTIs are quantified by the Berry phase, Berry connection, and an invariant known as the Chern number. Also the physical meaning of the Berry phase, connection, and curvature, how these quantities arise in electromagnetic problems, and the significance of Chern numbers for unidirectional, scattering-immune surface wave propagation are discussed. The Chern numbers for the electromagnetic modes supported by a biased plasma have been calculated. It has been demonstrated that the modes supported by biased plasmas indeed possess non-trivial Chern numbers, which leads to the propagation of a topologically protected and unidirectional surface modes (energy) at the interface between the biased plasma and topologically trivial material

  13. 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

  14. Panels of microporous insulation

    Energy Technology Data Exchange (ETDEWEB)

    McWilliams, J.A.; Morgan, D.E.; Jackson, J.D.J.

    1990-08-07

    Microporous thermal insulation materials have a lattice structure in which the average interstitial dimension is less than the mean free path of the molecules of air or other gas in which the material is arranged. This results in a heat flow which is less than that attributable to the molecular heat diffusion of the gas. According to this invention, a method is provided for manufacturing panels of microporous thermal insulation, in particular such panels in which the insulation material is bonded to a substrate. The method comprises the steps of applying a film of polyvinyl acetate emulsion to a non-porous substrate, and compacting powdery microporous thermal insulation material against the film so as to cause the consolidated insulation material to bond to the substrate and form a panel. The polyvinyl acetate may be applied by brushing or spraying, and is preferably allowed to dry prior to compacting the insulation material. 1 fig.

  15. Device intended for measurement of induced trapped charge in insulating materials under electron irradiation in a scanning electron microscope

    International Nuclear Information System (INIS)

    Belkorissat, R; Benramdane, N; Jbara, O; Rondot, S; Hadjadj, A; Belhaj, M

    2013-01-01

    A device for simultaneously measuring two currents (i.e. leakage and displacement currents) induced in insulating materials under electron irradiation has been built. The device, suitably mounted on the sample holder of a scanning electron microscope (SEM), allows a wider investigation of charging and discharging phenomena that take place in any type of insulator during its electron irradiation and to determine accurately the corresponding time constants. The measurement of displacement current is based on the principle of the image charge due to the electrostatic influence phenomena. We are reporting the basic concept and test results of the device that we have built using, among others, the finite element method for its calibration. This last method takes into account the specimen chamber geometry, the geometry of the device and the physical properties of the sample. In order to show the possibilities of the designed device, various applications under different experimental conditions are explored. (paper)

  16. Development of a readily recyclable sound insulation material made of polyester fibers. Application of the PET fibers from plastic bottles; Recycle kanona jidoshayo polyester sei kyuon zairyo no kaihatsu. Shiyozumi pet bottle zai no insulator zai eno tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, K; Watanabe, K; Sugawara, H; Minemura, Y [Nissan Motor Co. Ltd., Tokyo (Japan)

    1997-10-01

    We have developed new polyester sound-absorbing materials made of fine and modified-cross-section polyester fabric. They provide noticeably higher sound-absorbing performance than traditional materials. Another feature of the new materials is their excellent recyclability since they are made of polyester. Application of the new materials to the dash silencer and the floor carpeting produced a great improvement in sound-insulation performance with less weight. 2 refs., 7 figs.

  17. Dynamic Test Method Based on Strong Electromagnetic Pulse for Electromagnetic Shielding Materials with Field-Induced Insulator-Conductor Phase Transition

    Science.gov (United States)

    Wang, Yun; Zhao, Min; Wang, Qingguo

    2018-01-01

    In order to measure the pulse shielding performance of materials with the characteristic of field-induced insulator-conductor phase transition when materials are used for electromagnetic shielding, a dynamic test method was proposed based on a coaxial fixture. Experiment system was built by square pulse source, coaxial cable, coaxial fixture, attenuator, and oscilloscope and insulating components. S11 parameter of the test system was obtained, which suggested that the working frequency ranges from 300 KHz to 7.36 GHz. Insulating performance is good enough to avoid discharge between conductors when material samples is exposed in the strong electromagnetic pulse field up to 831 kV/m. This method is suitable for materials with annular shape, certain thickness and the characteristic of field-induced insulator-conductor phase transition to get their shielding performances of strong electromagnetic pulse.

  18. 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.)

  19. Self-Healing Wire Insulation

    Science.gov (United States)

    Parrish, Clyde F. (Inventor)

    2012-01-01

    A self-healing system for an insulation material initiates a self-repair process by rupturing a plurality of microcapsules disposed on the insulation material. When the plurality of microcapsules are ruptured, reactants within the plurality of microcapsules react to form a replacement polymer in a break of the insulation material. This self-healing system has the ability to repair multiple breaks in a length of insulation material without exhausting the repair properties of the material.

  20. Research on material of high temperature cable and wire insulation by γ-rays

    International Nuclear Information System (INIS)

    Jia Shaojin; Zhang Zhicheng; Xu Xiangling; Ge Xuewu; Ye qiang; Wang Feng

    2000-01-01

    Radiation-crosslinking improves a number of essential properties of polymers, so the high -temperature-resistance of polyethylene (PE) was increased by irradiation. The national products of High -density-polyethylene (HDPE), crosslinking promoters, flame-retardant, antioxidants, Si rubber, and Ethylene-propylene-monomer (EPDM) were used as cable insulation. After -irradiation, thermal-endurance can get above 135, and high flame retardance was firmed, Oxygen index can get above 32 by crosslinking

  1. Timber Chips as the Insulation Material for Energy Saving in Prefabricated Offices

    Directory of Open Access Journals (Sweden)

    Yupeng Wang

    2016-06-01

    Full Text Available This research demonstrates the feasibility of a roof insulation method for prefabricated offices that uses vinyl packed timber chips to reduce air conditioning loads (hereinafter referred to as AC loads and which also improves indoor thermal comfort. The advantages of the new roof insulation method were revealed through comparing the impacts of four roof types on prefabricated offices. The AC load and indoor thermal comfort (surface temperature and air temperature were evaluated. The disposal of scrap timber discarded from building construction projects is costing money, and is also a waste of natural resources. The assessment of a new roof insulation method with timber chips demonstrates the advanced usage of timber chips, reducing the environmental load in the building construction process. On the other hand, since prefabricated offices have lower thermal storage capacities and are less airtight than RC (reinforced concrete or S (steel structured buildings, the AC load consumption and indoor thermal comfort exacerbation in prefabricated offices is more serious. Especially in summer, a large amount of solar energy absorption from the roof raises the indoor air temperature and significantly increases the cooling load. This research contributes to the environmental design for prefabricated offices, and develops a method for the reuse of wood chips.

  2. Low emissivity insulating glazing materials: principle and examples; Les vitrages isolants a basse emissivite: principe et exemples

    Energy Technology Data Exchange (ETDEWEB)

    Prost, A. [Saint-Gobain Recherche, 93 - Aubervilliers (France)

    1996-12-31

    One of the stakes of flat glass industry is the limitation of thermal losses from indoor to outdoor through glass walls (K coefficient) in order to increase energy savings. Thermal insulation performances of a double glazing can be reinforced by the application of a highly reflective (low emissive) film with respect to thermal infrared radiation. The low emissive character is obtained with the use of surface-deposited materials that can be described using the Drude model: vacuum pulverization of metals, and vacuum pulverization or pyrolysis deposition of doped semi-conductor oxides. (J.S.)

  3. Toroidal field magnets for ZEPHYR tape and bitter concepts conductor and insulation materials

    International Nuclear Information System (INIS)

    Breit, E.; Brossmann, U.; Gruber, J.E.; Haubenberger, W.D.; Jandl, O.; Kamm, S.; Mast, F.; Mukherjee, S.; Soell, M.; Springmann, E.

    1981-08-01

    The general design aspects of the Toroidal Field Magnet System for a compact ignition experiment ZEPHYR are discussed. The 17 Tesla field calls for a steel reinforcement of the copper conductor. Two different types of magnet systems, a tape magnet and a Bitter magnet, are possible. In both systems the coils will be arranged in a steel casing. Force transfer is achieved by steel wedges between the coil casings. The mechanical stresses of the magnet structure were calculated by employing finite element methods. The pulse-operated magnet system will be force-cooled by liquid nitrogen to an initial starting temperature of 80 K before each single field pulse is applied. The problems of spacer cooling as well as the finally chosen channel cooling are discussed. The steel-reinforced copper conductor was developed in collaboration with industry, resulting in a high strength (700 N/mm 2 ) copper/austenite compound. The insulation system consisting of a glass/kapton wrapping of the conductors and of vacuum impregnation with an epoxy resin has to withstand high mechanical loads and a neutron/gamma irradiation in the order of 5 x 10 9 rad. The static and cyclic fatigue strength of different insulation systems at ambient and liquid nitrogen temperature has been investigated in mechanical tests of tension, compression and shear samples. The radiation resistance of the insulation resin was tested with gamma and neutron/gamma irradiation to doses of 10 10 rad. The aspects of field diffusion in the tape magnet are given in the appendix. (orig.)

  4. Survey of thermal insulation systems

    International Nuclear Information System (INIS)

    Kinoshita, Izumi

    1983-01-01

    Better thermal insulations have been developed to meet the growing demands of industry, and studies on thermal insulation at both high temperature and low temperature have been widely performed. The purpose of this survey is to summarize data on the performances and characteristics of thermal insulation materials and thermal insulation structures (for instance, gas cooled reactors, space vehicles and LNG storage tanks), and to discuss ravious problems regarding the design of thermal insulation structures of pool-type LMFBRs. (author)

  5. Evaluation of the cryogenic mechanical properties of the insulation material for ITER Feeder superconducting joint

    Science.gov (United States)

    Wu, Zhixiong; Huang, Rongjin; Huang, ChuanJun; Yang, Yanfang; Huang, Xiongyi; Li, Laifeng

    2017-12-01

    The Glass-fiber reinforced plastic (GFRP) fabricated by the vacuum bag process was selected as the high voltage electrical insulation and mechanical support for the superconducting joints and the current leads for the ITER Feeder system. To evaluate the cryogenic mechanical properties of the GFRP, the mechanical properties such as the short beam strength (SBS), the tensile strength and the fatigue fracture strength after 30,000 cycles, were measured at 77K in this study. The results demonstrated that the GFRP met the design requirements of ITER.

  6. Extended defects in insulating MgAl2O4 ceramic materials studied by PALS methods

    International Nuclear Information System (INIS)

    Klym, H; Ingram, A; Shpotyuk, O; Filipecki, J; Hadzaman, I

    2010-01-01

    Extended positron-trapping defects in technological modified insulating nanoporous MgAl 2 O 4 ceramics are characterized by positron annihilation lifetime spectroscopy. The results are achieved using three-component fitting procedure with arbitrary lifetimes applied to treatment of measured spectra. Within this approach, the first component in the lifetime spectra reflects microstructure specificity of the spinel structure, the second component responsible to extended defects near intergranual boundaries and the third component correspond to ortho-positronium 'pick-off' decaying in nanopores of ceramics. It is shown that in ceramics of different technological modifications the same type of positron traps prevails.

  7. Comparative Investigation on the Performance of Modified System Poles and Traditional System Poles Obtained from PDC Data for Diagnosing the Ageing Condition of Transformer Polymer Insulation Materials

    Directory of Open Access Journals (Sweden)

    Jiefeng Liu

    2018-02-01

    Full Text Available The life expectancy of a transformer is largely depended on the service life of transformer polymer insulation materials. Nowadays, several papers have reported that the traditional system poles obtained from polarization and depolarization current (PDC data can be used to assess the condition of transformer insulation systems. However, the traditional system poles technique only provides limited ageing information for transformer polymer insulation. In this paper, the modified system poles obtained from PDC data are proposed to assess the ageing condition of transformer polymer insulation. The aim of the work is to focus on reporting a comparative investigation on the performance of modified system poles and traditional system poles for assessing the ageing condition of a transformer polymer insulation system. In the present work, a series of experiments have been performed under controlled laboratory conditions. The PDC measurement data, degree of polymerization (DP and moisture content of the oil-immersed polymer pressboard specimens were carefully monitored. It is observed that, compared to the relationships between traditional system poles and DP values, there are better correlations between the modified system poles and DP values, because the modified system poles can obtain much more ageing information on transformer polymer insulation. Therefore, the modified system poles proposed in the paper are more suitable for the diagnosis of the ageing condition of transformer polymer insulation.

  8. Thin-film composite materials as a dielectric layer for flexible metal-insulator-metal capacitors.

    Science.gov (United States)

    Tiwari, Jitendra N; Meena, Jagan Singh; Wu, Chung-Shu; Tiwari, Rajanish N; Chu, Min-Ching; Chang, Feng-Chih; Ko, Fu-Hsiang

    2010-09-24

    A new organic-organic nanoscale composite thin-film (NCTF) dielectric has been synthesized by solution deposition of 1-bromoadamantane and triblock copolymer (Pluronic P123, BASF, EO20-PO70-EO20), in which the precursor solution has been achieved with organic additives. We have used a sol-gel process to make a metal-insulator-metal capacitor (MIM) comprising a nanoscale (10 nm-thick) thin-film on a flexible polyimide (PI) substrate at room temperature. Scanning electron microscope and atomic force microscope revealed that the deposited NCTFs were crack-free, uniform, highly resistant to moisture absorption, and well adhered on the Au-Cr/PI. The electrical properties of 1-bromoadamantane-P123 NCTF were characterized by dielectric constant, capacitance, and leakage current measurements. The 1-bromoadamantane-P123 NCTF on the PI substrate showed a low leakage current density of 5.5 x 10(-11) A cm(-2) and good capacitance of 2.4 fF at 1 MHz. In addition, the calculated dielectric constant of 1-bromoadamantane-P123 NCTF was 1.9, making them suitable candidates for use in future flexible electronic devices as a stable intermetal dielectric. The electrical insulating properties of 1-bromoadamantane-P123 NCTF have been improved due to the optimized dipole moments of the van der Waals interactions.

  9. Lambda as a factor for saving energy. When are special high-performance insulating materials worthwhile?; Einsparfaktor Lambda. Wann rechnen sich besonders leistungsfaehige Daemmstoffe?

    Energy Technology Data Exchange (ETDEWEB)

    Tornow, Sven-Erik [Arbeitskreis Baufachpresse e.V., Koeln (Germany)

    2011-01-15

    The probably most important criterion of an insulating material is its specific thermal conductivity. The so-called lambda value describes the amount of heat which flows in one second at a temperature difference of one Kelvin through one square meters of a one meter thick layer of a material. The lower the lambda-value, the much better. While usual insulating materials exist in the heat conductance stages 035 to 045, in the meantime the manufactures overestimate oneself with super-insulating materials whose thermal conductivity reach a value of 0.019. VIP panels have a heat conductivity to approximately 0.006 W/(m{sup 2} K). This is a high damming performance,which has its price.

  10. A comparison of atom and ion induced SSIMS - evidence for a charge induced damage effect in insulator materials

    International Nuclear Information System (INIS)

    Brown, A.; Berg, J.A. van den; Vickerman, J.C.

    1985-01-01

    A static secondary ion mass spectrometry (SSIMS) study of two very low conductivity materials, polystyrene and niobium pentoxide, using on the one hand a primary ion beam with electron neutralisation, and on the other, atom bombardment, shows that whilst the initial spectra obtained were quite similar, subsequent damage effects were much greater under ion impact conditions. For an equivalent flux density the half-life of the polystyrene surface structure was four times longer under atom bombardment. Significant reduction of the niobium surface was observed under ion bombardment whereas an equivalent atom flux had little apparent effect on the surface oxidation state. These data suggest that the requirement to dissipate the charge delivered to the sample by the primary ion beam contributes significantly to the damage mechanisms in electrically insulating materials. (author)

  11. Wall insulation system

    Energy Technology Data Exchange (ETDEWEB)

    Kostek, P.T.

    1987-08-11

    In a channel specially designed to fasten semi-rigid mineral fibre insulation to masonry walls, it is known to be constructed from 20 gauge galvanized steel or other suitable material. The channel is designed to have pre-punched holes along its length for fastening of the channel to the drywall screw. The unique feature of the channel is the teeth running along its length which are pressed into the surface of the butted together sections of the insulation providing a strong grip between the two adjacent pieces of insulation. Of prime importance to the success of this system is the recent technological advancements of the mineral fibre itself which allow the teeth of the channel to engage the insulation fully and hold without mechanical support, rather than be repelled or pushed back by the inherent nature of the insulation material. After the insulation is secured to the masonry wall by concrete nail fastening systems, the drywall is screwed to the channel.

  12. Secondary emission ion analyzer provided with an electron gun for insulating material analysis

    International Nuclear Information System (INIS)

    Blanchard, Bruno; Carrier, Patrick; Marguerite, J.-L.; Rocco, J.-C.

    1976-01-01

    This invention relates to a secondary emission ion analyser, fitted with an electron gun. It is used in the mass spectrometry analysis of electrically insulating bodies. It has already been suggested to bombard the target with an electron beam in conjunction with the beam of primary particles, in order to reduce the space charge near the target. The object of this invention is the application of this known process to appliances of the ion analyser type with a high electric field near the target. Its main characteristic is the use of an electron gun emitting an electron beam through the extraction lens placed opposite the target. The extraction electric field influences the path of the electrons but the electric and mechanical specifications of the electron gun in the invention are such that the target is correctly sprayed by the electron beam [fr

  13. 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.

  14. Opportunities in chemistry and materials science for topological insulators and their nanostructures

    KAUST Repository

    Kong, Desheng; Cui, Yi

    2011-01-01

    of these exotic materials to use the metallic states in functional devices, and they present great opportunities for the chemistry and materials science research communities. © 2011 Macmillan Publishers Limited. All rights reserved.

  15. 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.

  16. 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

  17. Effect of Slow External Flow on Flame Spreading over Solid Material: Opposed Spreading over Polyethylene Wire Insulation

    Science.gov (United States)

    Fujita, O.; Nishizawa, K.; Ito, K.; Olson, S. L.; Kashigawa, T.

    2001-01-01

    The effect of slow external flow on solid combustion is very important from the view of fire safety in space because the solid material in spacecraft is generally exposed to the low air flow for ventilation. Further, the effect of low external flow on fuel combustion is generally fundamental information for industrial combustion system, such as gas turbine, boiler incinerator and so on. However, it is difficult to study the effect of low external flow on solid combustion in normal gravity, because the buoyancy-induced flow strongly disturbs the flow field, especially for low flow velocity. In this research therefore, the effect of slow external flow on opposed flame spreading over polyethylene (PE) wire insulation have been investigated in microgravity. The microgravity environment was provided by Japan Microgravity Center (JAMIC) in Japan and KC-135 at NASA GRC. The tested flow velocity range is 0-30cm/s with different oxygen concentration and inert gas component.

  18. Life estimation I and C cable insulation materials based on accelerated life testing accelerated life testing

    International Nuclear Information System (INIS)

    Santhosh, T.V.; Ramteke, P.K.; Shrestha, N.B.; Ahirwar, A.K.; Gopika, V.

    2016-01-01

    Accelerated Iife tests are becoming increasingly popular in today's industry due to the need for obtaining life data quickly and reliably. Life testing of products under higher stress levels without introducing additional failure modes can provide significant savings of both time and money. Correct analysis of data gathered via such accelerated life testing will yield parameters and other information for the product's life under use stress conditions. To be of practical use in assessing the operational behaviour of cables in NPPs, laboratory ageing aims to mimic the type of degradation observed under operational conditions. Conditions of testing therefore need to be carefully chosen to ensure that the degradation mechanism occurring in the accelerated tests are similar to those which occur in service. This paper presents the results of an investigation in which the elongation-at-break (EAB) measurements were carried on a typical control cable to predict the mean life at service conditions. A low voltage polyvinyl chloride (PVC) insulated and PVC sheathed control cable, used in NPP instrumentation and control (I and C) applications, was subjected thermal ageing at three elevated temperatures

  19. 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...... with Ca/Si molar ratio of 1, to which Fe2O3 is added with Fe/Si molar ratios of 0.1, 0.5, 0.7, 1.0, and 1.3%. Structure and morphology of the porous calcium silicate, with different iron concentrations, are investigated using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). FTIR...... 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...

  20. Report on the program of 4 K irradiation of insulating materials for the Superconducting Super Collider

    International Nuclear Information System (INIS)

    Spindel, A.

    1993-07-01

    This report is intended to serve as an aid to material selection. The results reported herein are the product of a careful investigation and can be used with confidence in their validity. The selection of materials based on this data, however, is not the responsibility of the author. This report will not approve or disapprove any specific material for use in the Super Collider. The author of this report does not assume any design responsibility or responsibility for material selection for any application. It is, therefore, very important that those with design responsibility use this report wisely. For this reason, the following informational guide to the material selection process has been provided. There are several issues to take into account when evaluating a material for radiation resistance. It is very important that the design criteria and operating loads for the application be known. For many applications the actual loading, and therefore required properties, are unknown. Certain materials have empirically been used successfully in a similar application and those materials have often been selected on that basis. Both percent degradation and the magnitude of the actual properties after irradiation need to be considered. Consider the scenario where two materials are being compared that both have acceptable properties after exposure to 10 9 rads. It is preferable to choose the material with less degradation because degradation tends to be a threshold phenomena with properties declining rapidly with dose after a certain threshold dose. The properties of the initially strong material, therefore, will be extremely sensitive to dose in that dose range and slight magnet-to-magnet differences in dose may, depending on the application, lead to performance variations

  1. Density of loose-fill insulation material exposed to cyclic humidity conditions

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    the granulated loose-fill material is exposed to a climate that is characterised as cyclic humidity conditions (a constant temperature and a relative humidity alternating between two predetermined constant relative humidity levels). A better understanding of the behaviour of granulated loose-fill material...

  2. Radiation resistance of cable insulation and jacket materials for nuclear power plants

    International Nuclear Information System (INIS)

    Morita, Minoru; Kon, Shuji; Nishikawa, Ichiro

    1978-01-01

    The cables for use in nuclear power plants are required to satisfy the specific environmental resistance and excellent flame resistance as stipulated in IEEE Std. 383. The materials to be used to cables intended for this specific purpose of use must therefore be strictly tested so as to evaluate their flame resistance in addition to compliance with various environmental requirements, such as heat resistance, water-vapor resistance, and radiation resistance. This paper describes general information on radiation resistance and deterioration of various high-molecular materials, suggests the direction of efforts to be made to improve their properties including flame resistance of various rubber and plastic materials for cables to be used in nuclear power plants, and indicates the performance characteristics of such materials. (author)

  3. Thermal insulating materials consisting of polyurethane rigid foam. Production - application - properties. 2. ed.; Waermedaemmstoffe aus Polyurethan-Hartschaum. Herstellung - Anwendung - Eigenschaften

    Energy Technology Data Exchange (ETDEWEB)

    Endres, Edmund; Kleser, Joachim

    2008-02-15

    Using rigid polyurethane (PU) / polyisocyanurate (PIR) foam as a thermal insulation material enables a conservation of resources and energy conservation. Environmentally harmful emissions significantly are reduced. Under this aspect, the authors of the contribution report on the production, application, technical and physical properties of rigid polyurethane foams. Sustainable construction with rigid polyurethane foam, quality assurance and product certification are further topics of this paper.

  4. 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

  5. Effect of the insulation materials filling on the thermal performance of sintered hollow bricks under the air-conditioning intermittent operation

    Directory of Open Access Journals (Sweden)

    Chaoping Hou

    2018-06-01

    Full Text Available Wall insulation performance is an important factor affecting building energy consumption and indoor comfortable level. This study proposes that the insulation materials are filled into the cavities of the sintered hollow brick to replace the single insulation layer. The physical models of typical walls were built by the hollow bricks filled with expanding polystyrene board (EPS in cavities and wall thermal performance is numerically analyzed by the Finite Volume Method under air-conditioning intermittent operation, which conforms to the actual operation rules of air-conditioning. Results show that filling EPS in cavities is beneficial to improve the thermal performance of the bricks, and the larger the EPS filling ratio, the higher the thermal performance improvement. The EPS filling ratio increase has the higher sensitivity on inner surface heat flow under the low EPS filling ratio, and filling EPS in the external cavities is optimum with the decrement rate 5.92% higher than filling EPS in internal cavities for the EPS filling ratio of 20%, while filling EPS in internal and external cavities simultaneously is optimum with decrement rate 2.45%–6.87% higher than that with filling EPS in the internal cavities for the EPS filling ratio of 40%–80%. Keywords: Insulation filling ratio, Insulation filling location, Thermal performance, Sintered hollow bricks

  6. On the improvement of mechanical properties of monolithic silica aerogels (for transparent insulating material); Silica aerogel (tomei dannetsu zairyo) kyodo no kaizen ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Tajiri, K; Igarashi, K; Tanemura, S [National Industrial Research Institute of Nagoya, Nagoya (Japan)

    1997-11-25

    Study was made on improvement of the strength of silica aerogel as transparent insulating material. Silica aerogel is a low-density porous material with high heat insulation and transparency. To develop a insulating material with high transparency, monolithic silica aerogel was studied. For direct use of it for windows, its strength improvement was attempted. The aerogel was prepared by supercritical drying (alcohol or CO2) of silica wet gel obtained by hydrolysis and condensation of silicon alkoxide solution. To prepare the aerogel bonded on plate glass for strength improvement, the aerogel was bonded to alkoxide by exposing active silanol radical through F-etching of plate glass surface. However, to obtain the practical large-area bonded aerogel, shrinkage control of the aerogel in supercritical drying was necessary. Addition of Laponite into a silica network for strength improvement by polymer increased the bending strength by 50%. Although some reduction of its transparency was observed because of clouding, its heat insulation was stable. Further strength improvement is necessary for its practical use. 5 figs., 1 tab.

  7. A New Generation of Building Insulation by Foaming Polymer Blend Materials with CO2

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Arthur [Industrial Science & Technology Network, Inc., Lancaster, PA (United States); Domszy, Roman [Industrial Science & Technology Network, Inc., Lancaster, PA (United States); Yang, Jeff [Industrial Science & Technology Network, Inc., Lancaster, PA (United States)

    2016-03-30

    Advanced thermal insulation is among the most effective technologies in transforming our nation’s energy system and contributing to DOE’s stated goal of 50% less building energy consumption by 2030. The installation of an advanced thermal insulation would prevent energy waste without the need for any maintenance, and ISTN conservatively estimates that the commercialization of such a new technology would contribute to annual U.S. energy savings of 0.361 Quads and $8 billion in annual economic savings. The key challenge to improving building insulation is to maintain and surpass the industry standard of R-5 per inch insulation value in a cost-competitive manner. Improvements in R-value without cost-efficiency are not likely to impact the market given the cost-sensitive nature of the construction industry (insulation is already the lowest-cost component of the building envelope). However, significantly higher insulating value at competitive costs is extremely appealing to the market given the greater potential to save on energy consumption and costs over the long-term. Thus, our goal is to develop a super-thermal insulation with 50% greater insulation value (R-9 to R-10 per inch) and manufacturing costs that are equal on a per-R-value basis (< $0.70/ft2).

  8. An interim report on the materials and selection criteria analysis for the Compact Ignition Tokamak toroidal field coil turn-to-turn insulation system

    International Nuclear Information System (INIS)

    Campbell, V.W.; Dooley, J.B.; Hubrig, J.G.; Janke, C.J.; McManamy, T.J.; Welch, D.E.

    1990-01-01

    This document contains photographs showing the results of laboratory testing of the combinations of epoxy resins, hardeners, and cures undertaken as part of the Compact Ignition Tokamak Insulation Screening Program. Cryogenic shock and soak to equilibrium proved to be the most demanding condition for these materials. The degree of damage to the basic materials when a poor candidate is selected is shown to be quite dramatic. 34 figs

  9. Localized Electron Trap Modification as a Result of Space Weather Exposure in Highly Disordered Insulating Materials

    Science.gov (United States)

    2017-03-06

    produced by Trek Inc. Trek probe model 370 is capable of -3 to 3kV and has an extremely fast, 50µs/kV response to changing surface potentials. Trek probe...This motor can move a Trek 370 surface potential probe (± 3 kV range) and a Faraday cup mounted at opposite ends of a propeller-shaped bracket...Spacecraft Charging, in Reference Publication, 1995, NASA . 35. Horowitz, G., Organic field-effect transistors, Advanced Materials, 1998, 10(5), pp. 365

  10. Ablation, surface activation, and electroless metallization of insulating materials by pulsed excimer laser irradiation

    International Nuclear Information System (INIS)

    Lowndes, D.H.; Godbole, M.J.; Pedraza, A.J.

    1993-01-01

    Pulsed-laser irradiation of wide bandgap ceramic substrates, using photons with sub-bandgap energies, activates the ceramic surface for subsequent electroless copper deposition. The copper deposit is confined within the irradiated region when the substrate is subsequently immersed in an electroless copper bath. However, a high laser fluence (typically several j/cm 2 ) and repeated laser shots are needed to obtain uniform copper coverage by this direct-irradiation process. In contrast, by first applying an evaporated SiO x thin film (with x ∼1), laser ablation at quite low energy density (∼0.5 J/cm 2 ) results in re-deposition on the ceramic substrate of material that is catalytic for subsequent electroless copper deposition. Experiments indicate that the re-deposited material is on silicon, on which copper nucleates. Using an SiO x film on a laser-transparent substrate, quite fine (∼12 μm) copper lines can be formed at the boundary of the region that is laser-etched in SiO x . Using SiO x with an absorbing (polycrystalline) ceramic substrate, more-or-less uniform activation and subsequent copper deposition are obtained. In the later case, interactions with the ceramic substrate also may be important for uniform deposition

  11. Final Report: Stability and Novel Properties of Magnetic Materials and Ferromagnet / Insulator Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, Paul M. [Univ. of Wisconsin, Madison, WI (United States); Chang, Y. Austin [Univ. of Wisconsin, Madison, WI (United States)

    2013-07-24

    We report investigations of the synthesis, structure, and properties of new materials for spintronic applications integrated onto silicon substrates. Our primary focus is materials with very high, negative, intrinsic spin polarization of the density of states at the Fermi level. We have developed a new synthesis method for Fe3O4 thin films through selective oxidation of Fe, resulting in smooth, low-defect density films. We have synthesized Fe4N films and shown that they preferentially oxidize to Fe3O4. When integrated into magnetic tunnel junctions consisting of Fe4N / AlOx / Fe, oxidation at the Fe4N / AlOx interface creates Fe3O4, leading to negative tunneling magnetoresistance (TMR). Oxidation of Fe in nominally symmetric CoFe / AlOx / CoFe also produces Fe3O4 and negative TMR under selected oxidation conditions.

  12. Creation of excitations and defects in insulating materials by high-current-density electron beams of nanosecond pulse duration

    International Nuclear Information System (INIS)

    Vaisburd, D.I.; Evdokimov, K.E.

    2005-01-01

    The paper is concerned with fast and ultra-fast processes in insulating materials under the irradiation by a high-current-density electron beam of a nanosecond pulse duration. The inflation process induced by the interaction of a high-intensity electron beam with a dielectric is examined. The ''instantaneous'' distribution of non-ionizing electrons and holes is one of the most important stages of the process. Ionization-passive electrons and holes make the main contribution to many fast processes with a characteristic time in the range 10 -14 /10 -12 s: high-energy conductivity, intraband luminescence, etc. A technique was developed for calculation of the ''instantaneous'' distribution of non-ionizing electrons and holes in a dielectric prior to electron-phonon relaxation. The following experimental effects are considered: intraband luminescence, coexistence of intraband electron luminescence and band-to-band hole luminescence in CsI, high energy conductivity; generation of mechanical fields and their interaction with cracks and dislocations. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. An interim report on the materials and selection criteria analysis for the Compact Ignition Tokamak Toroidal Field Coil Turn-to-Turn Insulation System

    International Nuclear Information System (INIS)

    Campbell, V.W.; Dooley, J.B.; Hubrig, J.G.; Janke, C.J.; McManamy, T.J.; Welch, D.E.

    1990-01-01

    Design criteria for the Compact Ignition Tokamak, Toroidal-Field (TF) Coil, Turn-to-Turn Insulation System require an insulation sheet and bonding system that will survive cryogenic cycling in a radiation environment and maintain structural integrity during exposure to the significant compressive and shear loads associated with each operating cycle. For thermosetting resin systems, a complex interactive dependency exists between optimum peak value, in-service property performance capabilities of candidate generic materials; key handling and processing parameters required to achieve their optimum in-service property performance as an insulation system; and suitability of their handling and processing parameters as a function of design configuration and assembly methodology. This dependency is assessed in a weighted study matrix in which two principal programmatic approaches for the development of the TF Coil Subassembly Insulation System have been identified. From this matrix study, two viable approaches to the fabrication of the insulation sheet were identified: use of a press-formed sheet bonded in place with epoxy for mechanical bonding and tolerance take-up and formation of the insulation sheet by placement of dry cloth and subsequent vacuum pressure impregnation. Laboratory testing was conducted to screen a number of combinations of resins and hardeners on a generic basis. These combinations were chosen for their performance in similar applications. Specimens were tested to screen viscosity, thermal-shock tolerance, and cryogenic tolerance. Cryogenic shock and cryogenic temperature proved to be extremely lethal to many combinations of resin, hardener, and cure. Two combinations survived: a heavily flexibilized bisphenol A resin with a flexibilized amine hardener and a bisphenol A resin with cycloaliphatic amine hardener. 7 refs., 12 figs., 6 tabs

  14. Gaseous products and smoke generation on combustion of the insulation materials of nuclear cables

    International Nuclear Information System (INIS)

    Noguchi, Isamu; Takami, Hiroshi; Ueyama, Michio; Fujimura, Shun-ichi.

    1976-01-01

    Serious requirements have been introduced to the cables used for nuclear power plants on their flame retardation in the IEEE Standard 383-1974. The movements that the users prescribe the quantity of corrosive gas generated from cables are also observed. This report describes on the measured results of the gaseous products generated by burning polyethylene, polyvinyl-chloride (PVC) and their flame-resistant products, and a part of the covering materials of the cables for nuclear power plants (flame-resistant, crosslinking polyethylene, flame-resistant, low hydrochloric acid PVC, flame-resistant jute) in the infra-red rapid heating combustion test facility designed by the Furukawa Electric Co. Ltd. In addition, the report introduces the test method for the smoke generation evaluation of polymers and a part of the measured results. The gaseous products of combustion were collected and determined quantitatively by gas chromatographic method. Since smoke generation is affected greatly by the kinds, shape, atmosphere, temperature, ignition procedure and others of burnt matters, the establishment of the evaluation test method is difficult, and a number of methods have been proposed. As the measured results showed, it is clear that smoke generation increases with the increase of flame resistant reagent addition. The smoke generation of PVC was of course great in quantity because it contains considerable amount of chlorine for its molecular structure. Flame-resistant polyethylene generates smoke much more than polyethylene without flame-resisting treatment because of its flame resistivity, but less than that of PVC. (Wakatsuki, Y.)

  15. Thermal insulation

    International Nuclear Information System (INIS)

    Aspden, G.J.; Howard, R.S.

    1988-01-01

    The patent concerns high temperature thermal insulation of large vessels, such as the primary vessel of a liquid metal cooled nuclear reactor. The thermal insulation consists of multilayered thermal insulation modules, and each module comprises a number of metal sheet layers sandwiched between a back and front plate. The layers are linked together by straps and clips to control the thickness of the module. (U.K.)

  16. Achievement report for fiscal 1976 on research in materials for electrodes and insulation walls. Large-scale technology development (Research and development of magnetohydrodynamic power generation); 1976 nendo denkyoku oyobi zetsuenheki zairyo ni kansuru kenkyu seika

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-06-01

    This report covers the achievements attained in fiscal 1976 by the materials working group engaged in the study of materials for electrodes and insulation walls. Fabricated and tested in the study relative to the experimental fabrication of materials for magnetohydrodynamic (MHD) power generation are MgO-Si{sub 3}N{sub 4} based insulation materials, MgO-BN based insulation materials, tin oxide based electrode materials, ZrO{sub 2}-CeO{sub 2} based cold pressed electrode materials, cermet based electrode materials, etc. In the research on basic characteristics and measurement, various electrode materials and insulation wall materials are subjected to a 300-hour K{sub 2}SO{sub 4} corrosion test at 1,300 degrees C. In the simulation of MHD power generation, correlations are investigated between materials, cooling structures, and dynamic characteristics, and data are collected to enable the prediction of performance and consumption of the materials during power generation. A data processing system is developed for the said simulation, and this enhances experimenting efficiency. In the study of insulation wall structures and electrode phenomena, studies are conducted about the thermal stress in power generation duct wall materials, localized anomalous heating due to arc spots, and the transfer of heat between the power generation duct wall materials and the cooling material. (NEDO)

  17. Reducing heat transfer across the insulated walls of refrigerated truck trailers by the application of phase change materials

    International Nuclear Information System (INIS)

    Ahmed, Mashud; Meade, Oliver; Medina, Mario A.

    2010-01-01

    A general estimate shows that 80% of communities across the United States receive their goods exclusively by transport trucks, of which a significant number are climate-controlled because they carry perishable goods, pharmaceutical items and many other temperature-sensitive commodities. Keeping the inside of a truck trailer at a constant temperature and relative humidity requires exact amounts of heat and/or moisture management throughout the shipment period, which is regulated via small refrigeration units, placed outside the truck, that operate by burning fuel. These trucks, known as refrigerated truck trailers, are the focus of this paper. In the research presented herein, the conventional method of insulation of the refrigerated truck trailer was modified using phase change materials (PCMs). The limited research carried out in refrigerated transport compared to other refrigeration processes has left spaces for innovative solutions in this area. The research investigated the inclusion of paraffin-based PCMs in the standard trailer walls as a heat transfer reduction technology. An average reduction in peak heat transfer rate of 29.1% was observed when all walls (south, east, north, west, and top) were considered. For individual walls, the peak heat transfer rate was reduced in the range of 11.3-43.8%. Overall average daily heat flow reductions into the refrigerated compartment of 16.3% were observed. These results could potentially translate into energy savings, pollution abatement from diesel-burning refrigeration units, refrigeration equipment size reduction, and extended equipment operational life. The research and its results will help to better understand the scope of this technology.

  18. Reduction of heat insulation upon soaking of the insulation layer

    Science.gov (United States)

    Achtliger, J.

    1983-09-01

    Improved thermal protection of hollow masonry by introduction of a core insulation between the inner and outer shell is discussed. The thermal conductivity of insulation materials was determined in dry state and after soaking by water with different volume-related moisture contents. The interpolated thermal conductivity values from three measured values at 10 C average temperature are presented as a function of the pertinent moisture content. Fills of expanded polystyrene, perlite and granulated mineral fibers, insulating boards made of mineral fibers and in situ cellular plastics produced from urea-formaldehyde resin were investigated. Test results show a confirmation of thermal conductivity values for insulating materials in hollow masonry.

  19. Hydrothermal hardened high-temperature thermal insulation material CALUTHERM {sup registered} from hibonite and alumina cement. Pt. 1; Hydrothermal erhaerteter Hochtemperaturwaermedaemmstoff CALUTHERM {sup registered} aus Hibonit und Tonerdezement. T. 1

    Energy Technology Data Exchange (ETDEWEB)

    Hoelscher, Tobias; Schneider, Hans-Juergen [Calsitherm Silikatbaustoffe GmbH, Bad Lippspringe (Germany); Schlegel, Ernst

    2013-07-01

    The first part features an overview to the properties of all calcium aluminates followed by a presentation of CALUTHERM {sup registered}, a high temperature-thermal insulating material. CALUTHERM is produced on the bases of SLA-92, a calcium hexaaluminat aggregate, and calcium aluminate cement CA-14 W as binder. The comprehensive studies focus on properties and changes of these raw materials during the technological stages of the CALUTHERM's production. The second part will present CALUTHERM's properties and its variants throughout the production process. A possible correlation between the properties of raw materials and thermal insulation material is researched and finally application examples are presented. CALUTHERM is suited for thermal insulation up to 1600 C and has a remarkable low thermal conductivity near 0.4 W/m . K at these high temperatures. For that reason CALUTHERM is a top high-temperature thermal insulating material. (orig.)

  20. 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

  1. Dielectric strength behaviour and mechanical properties of transparent insulation materials suitable to optical monitoring of partial discharges

    International Nuclear Information System (INIS)

    Lothongkam, Chaiyaporn

    2014-01-01

    statistical analysis based on the 2-parameter Weibull distribution function. The investigations revealed that the virgin translucent silicone rubber has a large elastic region with an acceptable plastic deformation and also provides an AC 50 Hz dielectric strength of approximately 24 kV/mm for 0.5 mm thickness. These values enable considering the tested translucent silicone as replacement material for an opaque elastomer that is currently used for a rubber stress cone of HV cable accessories.. Unfortunately, its optical transmittance is poor compared to optically clear transparent silicone rubbers. On the other hand, the mechanical properties of virgin transparent silicone rubbers do not comply with those demanded from push-on stress cones. In particular, their elongation at break is considered too low for that application. However they provide the AC dielectric strength values in either 28 kV/mm or 29 kV/mm for 0.5 mm thickness, which are higher than those of the translucent type. Moreover, it was found that the post-curing process does not provide a positive impact on the ultimate elongation of silicone rubbers. Hence, the elongation at break of virgin transparent silicone rubbers must be improved before they can be used as insulating material for a rubber stress cone. In addition, the influence of mechanical tensile stress on the dielectric strength of the virgin translucent silicone rubber was investigated. The results show that mechanical tensile stress does not negatively influence on dielectric strength of such silicone rubber, so it can be well-operated under combined electrical and mechanical stresses. Beside the improvement of optical PD detection performance in the translucent silicone insulation materials, the influence of fluorescent dye's modification was investigated. The results indicate that the commercially available fluorescent dyes of 0.02 wt. % mixed into the translucent silicone polymer do not negatively influence on the E b value of such silicone

  2. Compliance of Bombardier's Challenger 604 and CRJ200 to FAR25.856(a) : flame propagation of thermal/acoustic insulation materials and future trends in aircraft materials fire safety

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, W.R. [Bombardier, Montreal, PQ (Canada); Schofield, C.M.A. [Transport Canada, Ottawa, ON (Canada)

    2007-07-01

    This paper provided details of a testing program designed to ensure the compliance of Bombardier's Challenger 604 to new rules established to improve flammability standards for thermal and acoustic insulation materials. The rule applied to both pressurized and unpressurized sections of the fuselage, as well as to ducting, sound damping foams, and insulation bags. Test samples of all non-metallic insulation components were collected. Testing of the samples was conducted in a chamber with an ignition source as well as a controlled heat flux provided by a radiant panel. The new rules were discussed as well as challenges faced by industry which will have to show compliance for flame propagation requirements. Issues related to the in-service replacement of thermal and acoustic insulation materials were reviewed along with potential changes to flammability regulations. Materials used by Bombardier for compliant constructions were also listed. It was concluded that the safety of airplane occupants will be improved through compliance to new testing methods under harsher fire threat conditions, with more stringent pass and fail criteria. 15 refs., 5 figs.

  3. A Review on Disorder-Driven Metal–Insulator Transition in Crystalline Vacancy-Rich GeSbTe Phase-Change Materials

    Science.gov (United States)

    Wang, Jiang-Jing; Xu, Ya-Zhi; Mazzarello, Riccardo; Wuttig, Matthias; Zhang, Wei

    2017-01-01

    Metal–insulator transition (MIT) is one of the most essential topics in condensed matter physics and materials science. The accompanied drastic change in electrical resistance can be exploited in electronic devices, such as data storage and memory technology. It is generally accepted that the underlying mechanism of most MITs is an interplay of electron correlation effects (Mott type) and disorder effects (Anderson type), and to disentangle the two effects is difficult. Recent progress on the crystalline Ge1Sb2Te4 (GST) compound provides compelling evidence for a disorder-driven MIT. In this work, we discuss the presence of strong disorder in GST, and elucidate its effects on electron localization and transport properties. We also show how the degree of disorder in GST can be reduced via thermal annealing, triggering a disorder-driven metal–insulator transition. The resistance switching by disorder tuning in crystalline GST may enable novel multilevel data storage devices. PMID:28773222

  4. A Review on Disorder-Driven Metal-Insulator Transition in Crystalline Vacancy-Rich GeSbTe Phase-Change Materials.

    Science.gov (United States)

    Wang, Jiang-Jing; Xu, Ya-Zhi; Mazzarello, Riccardo; Wuttig, Matthias; Zhang, Wei

    2017-07-27

    Metal-insulator transition (MIT) is one of the most essential topics in condensed matter physics and materials science. The accompanied drastic change in electrical resistance can be exploited in electronic devices, such as data storage and memory technology. It is generally accepted that the underlying mechanism of most MITs is an interplay of electron correlation effects (Mott type) and disorder effects (Anderson type), and to disentangle the two effects is difficult. Recent progress on the crystalline Ge₁Sb₂Te₄ (GST) compound provides compelling evidence for a disorder-driven MIT. In this work, we discuss the presence of strong disorder in GST, and elucidate its effects on electron localization and transport properties. We also show how the degree of disorder in GST can be reduced via thermal annealing, triggering a disorder-driven metal-insulator transition. The resistance switching by disorder tuning in crystalline GST may enable novel multilevel data storage devices.

  5. Electrical insulating liquid: A review

    Directory of Open Access Journals (Sweden)

    Deba Kumar Mahanta

    2017-08-01

    Full Text Available Insulating liquid plays an important role for the life span of the transformer. Petroleum-based mineral oil has become dominant insulating liquid of transformer for more than a century for its excellent dielectric and cooling properties. However, the usage of petroleum-based mineral oil, derived from a nonrenewable energy source, has affected the environment for its nonbiodegradability property. Therefore, researchers direct their attention to renewable and biodegradable alternatives. Palm fatty acid ester, coconut oil, sunflower oil, etc. are considered as alternatives to replace mineral oil as transformer insulation liquid. This paper gives an extensive review of different liquid insulating materials used in a transformer. Characterization of different liquids as an insulating material has been discussed. An attempt has been made to classify different insulating liquids-based on different properties.

  6. A Non-Ventilated Solar Façade Concept Based on Selective and Transparent Insulation Material Integration: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Miroslav Čekon

    2017-06-01

    Full Text Available A new solar façade concept based on transparent insulation and a selective absorber is proposed, tested and compared with conventional insulation and a non-selective type of absorber, respectively. The presented study focuses on an experimental non-ventilated solar type of façade exposed to solar radiation both in the laboratory and in outdoor tests. Due to the high solar absorbance level of the façade, high- and low-emissivity contributions were primarily analysed. All of the implemented materials were contrasted from the thermal and optical point of view. An analysis was made of both thermodynamic and steady state procedures affecting the proposed solar façade concept. Experimental full scale tests on real building components were additionally involved during summer monitoring. An indicator of the temperature response generated by solar radiation exposure demonstrates the outdoor performance of the façade is closely related to overheating phenomena. From the thermal point of view, the proposed transparent insulation and selective absorber concept corresponds to the performance of conventional thermal insulation of identical material thickness; however, the non-selective prototype only provides 50% thermal performance. The results of the solar-based experiments show that with a small-scale experimental prototype, approximately no significant difference is measured when compared with a non-selective absorber type. The only difference was achieved at the maximum of 2.5 K, when the lower temperature was obtained in the solar selective concept. At the full-scale outdoor mode, the results indicate a maximum of 3.0 K difference, however the lower temperature achieves a non-selective approach. This solar façade can actively contribute to the thermal performance of building components during periods of heating.

  7. A study on the barrier effect with respect to the condition of solid insulation materials in GN{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hong Seok; Mo, Young Kyu; Lee, On You; Kim, Jun Il; Bang, Seung Min; Kang, Jong O; Kang, Hyoung Ku [Dept. of Electrical Engineering, Korea National University of Transportation, Chungju (Korea, Republic of); Nam, Seo Ho [Dept. of Electrical and Electronic Engineering, Applied Superconductivity Lab., Yonsei University, Seoul (Korea, Republic of)

    2015-03-15

    High voltage superconducting apparatuses have been developed presently around the world under AC and DC sources. In order to improve electrical reliability of superconducting apparatuses with AC and DC networks, a study on the DC as well as the AC electrical breakdown characteristics of cryogenic insulations should be conducted for developing a high voltage superconducting apparatus. Recently, a sub-cooled liquid nitrogen cooling system is known to be promising method for developing a high voltage superconducting apparatus. A sub-cooled liquid nitrogen cooling system uses gaseous nitrogen to control the pressure and enhance the dielectric characteristics. However, the dielectric characteristics of gaseous nitrogen are not enough to satisfy the grade of insulation for a high voltage superconducting apparatus. In this case, the application of solid insulating barriers is regarded as an effective method to reinforce the dielectric characteristics of a high voltage superconducting apparatus. In this paper, it is dealt with a barrier effect on the DC and AC dielectric characteristics of gaseous nitrogen with respect to the position and number of solid insulating barriers. As results, the DC and AC electrical breakdown characteristics by various barrier effects is verified.

  8. Emerging Trends in Topological Insulators and Topological ...

    Indian Academy of Sciences (India)

    /fulltext/reso/022/08/0787-0800. Keywords. Superconductor, quantum Hall effect, topological insulator, Majorana fermions. Abstract. Topological insulators are new class of materials which arecharacterized by a bulk band gap like ordinary ...

  9. Recovery of waste and side products of apatite-nepheline and eudialyte ores processing in manufacture of heat-insulating foam glassy-crystalline materials

    Directory of Open Access Journals (Sweden)

    Suvorova O. V.

    2017-03-01

    Full Text Available Overburden and dressing tailings accumulated in the Murmansk region in impressive volumes represent serious challenges of both economic and ecological character. Maintenance of overburden dumps and dressing tailings involves considerable capital and material expenses. Therefore reprocessing of mining waste and manufacture of building materials, including heat-insulating foam-glass materials, is a promising trend. The work discusses the feasibility of recovering silica-containing waste and ore processing byproducts on the Kola Peninsula. Compositions and techniques for producing blocks and pellets from foam-glass crystalline materials have been developed. The effect of modifying agents on the foam-silicate materials' mechanical properties has been investigated. The production conditions for high-quality foam-silicate blocks have been identified. The foam silicates obtained under optimal conditions have featured a relatively low viscosity (0.3–0.5 g/cm³, high strength (up to 5 MPa and heat conductivity (0.09–0.107 Wt/m·K. Methods of improving the operating characteristics of foam silicates based on structure perfecting have been proposed. It has been found that as a result of shorttime baking of grainy samples the product has a grain strength of 5–6 MPa, density of 0.25–0.35 g/cm3 and a resistance to crushing in cylinder of 2.2–3 MPa, which is 2–3 times higher than that of a material subjected to one-stage thermal treatment. The water absorption of the material is 5–6 %, which is by a half lower compared to a one-stage treated material. The thermal conduction coefficient is 0.091–0.096 Wt/m·K. The obtained materials are recommended for use as heat-insulating surfacing and filling material for garrets, floors and roofs in construction and renovation of industrial and civic buildings

  10. Insulation structure of thermonuclear device

    International Nuclear Information System (INIS)

    Suzuki, Takayuki; Usami, Saburo; Tsukamoto, Hideo; Kikuchi, Mitsuru

    1998-01-01

    The present invention provides an insulating structure of a thermonuclear device, in which insulation materials between toroidal coils are not broken even if superconductive toroidal coils are used. Namely, a tokamak type thermonuclear device of an insulating structure type comprises superconductive toroidal coils for confining plasmas arranged in a circular shape directing the center each at a predetermined angle, and the toroidal coils are insulated from each other. The insulation materials are formed by using a biaxially oriented fiber reinforced plastics. The contact surface of the toroidal coils and the insulating materials are arranged so that they are contact at a woven surface of the fiber reinforced plastics. Either or both of the contact surfaces of the fiber reinforced plastics and the toroidal coils are coated with a high molecular compound having a low friction coefficient. With such a constitution, since the interlayer shearing strength of the biaxially oriented fiber reinforced plastics is about 1/10 of the compression strength, the shearing stress exerted on the insulation material is reduced. Since a static friction coefficient on the contact surface is reduced to provide a structure causing slipping, shearing stress does not exceeds a predetermined limit. As a result, breakage of the insulation materials between the toroidal coils can be prevented. (I.S.)

  11. Forming Refractory Insulation On Copper Wire

    Science.gov (United States)

    Setlock, J.; Roberts, G.

    1995-01-01

    Alternative insulating process forms flexible coat of uncured refractory insulating material on copper wire. Coated wire formed into coil or other complex shape. Wire-coating apparatus forms "green" coat on copper wire. After wire coiled, heating converts "green" coat to refractory electrical insulator. When cured to final brittle form, insulating material withstands temperatures above melting temperature of wire. Process used to make coils for motors, solenoids, and other electrical devices to be operated at high temperatures.

  12. Design of lightweight insulation packages for sports cars, component design, material selection and adoption of surrounding properties during the development of the new porsche Carrera Coupe

    Energy Technology Data Exchange (ETDEWEB)

    Lange, C. [Porsche (F.) AG, Weissach (Germany)

    2005-07-01

    Creating a proper insulation package for sports cars means to take into account not only an effective reduction of noise, but also weight optimisation, most possible reduction of package volume and to apply a suitable filter function to create sound. The Carrera's predecessor is a class leading vehicle concerning the weight of the damping and insulation package. Is it possible to improve its performance and shift targets positively? Is it time to exchange existing isolation components by absorption systems? The task for the new development was to style a lightweight trim package which offers a weight and a cost reduction at the same time. The layout considers the special requirements of a high performance sports car and combines the demand for long term rides with a very sporty response behaviour when driving at physical limits. The decision process of material selection is also strongly influenced by realised and expected changes in the design of the power train, chassis, body structure and interior trim components. The question arises if it is possible to regard all the changing noise components in the interior noise sound layout and wait for a final validation of the insulation and trim package until the very end of the development period. (orig.)

  13. Pulsed-voltage atom probe tomography of low conductivity and insulator materials by application of ultrathin metallic coating on nanoscale specimen geometry.

    Science.gov (United States)

    Adineh, Vahid R; Marceau, Ross K W; Chen, Yu; Si, Kae J; Velkov, Tony; Cheng, Wenlong; Li, Jian; Fu, Jing

    2017-10-01

    We present a novel approach for analysis of low-conductivity and insulating materials with conventional pulsed-voltage atom probe tomography (APT), by incorporating an ultrathin metallic coating on focused ion beam prepared needle-shaped specimens. Finite element electrostatic simulations of coated atom probe specimens were performed, which suggest remarkable improvement in uniform voltage distribution and subsequent field evaporation of the insulated samples with a metallic coating of approximately 10nm thickness. Using design of experiment technique, an experimental investigation was performed to study physical vapor deposition coating of needle specimens with end tip radii less than 100nm. The final geometries of the coated APT specimens were characterized with high-resolution scanning electron microscopy and transmission electron microscopy, and an empirical model was proposed to determine the optimal coating thickness for a given specimen size. The optimal coating strategy was applied to APT specimens of resin embedded Au nanospheres. Results demonstrate that the optimal coating strategy allows unique pulsed-voltage atom probe analysis and 3D imaging of biological and insulated samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Low-voltage organic field-effect transistors based on novel high-κ organometallic lanthanide complex for gate insulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qi; Li, Yi; Zhang, Yang; Song, You, E-mail: wangxzh@nju.edu.cn, E-mail: yli@nju.edu.cn, E-mail: yousong@nju.edu.cn; Wang, Xizhang, E-mail: wangxzh@nju.edu.cn, E-mail: yli@nju.edu.cn, E-mail: yousong@nju.edu.cn; Hu, Zheng [Key Laboratory of Mesoscopic Chemistry of MOE, Jiangsu Provincial Lab for Nanotechnology, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China. High-Tech Research Institute of Nanjing University (Suzhou), Suzhou 215123 (China); Sun, Huabin; Li, Yun, E-mail: wangxzh@nju.edu.cn, E-mail: yli@nju.edu.cn, E-mail: yousong@nju.edu.cn; Shi, Yi [School of Electronic Science and Engineering and Jiangsu Provincial Key Laboratory of Photonic and Electronic Materials, Nanjing University, Nanjing 210093 (China)

    2014-08-15

    A novel high-κ organometallic lanthanide complex, Eu(tta){sub 3}L (tta=2-thenoyltrifluoroacetonate, L = 4,5-pinene bipyridine), is used as gate insulating material to fabricate low-voltage pentacene field-effect transistors (FETs). The optimized gate insulator exhibits the excellent properties such as low leakage current density, low surface roughness, and high dielectric constant. When operated under a low voltage of −5 V, the pentacene FET devices show the attractive electrical performance, e.g. carrier mobility (μ{sub FET}) of 0.17 cm{sup 2} V{sup −1} s{sup −1}, threshold voltage (V{sub th}) of −0.9 V, on/off current ratio of 5 × 10{sup 3}, and subthreshold slope (SS) of 1.0 V dec{sup −1}, which is much better than that of devices obtained on conventional 300 nm SiO{sub 2} substrate (0.13 cm{sup 2} V{sup −1} s{sup −1}, −7.3 V and 3.1 V dec{sup −1} for μ{sub FET}, V{sub th} and SS value when operated at −30 V). These results indicate that this kind of high-κ organometallic lanthanide complex becomes a promising candidate as gate insulator for low-voltage organic FETs.

  15. Low-voltage organic field-effect transistors based on novel high-κ organometallic lanthanide complex for gate insulating materials

    Directory of Open Access Journals (Sweden)

    Qi Liu

    2014-08-01

    Full Text Available A novel high-κ organometallic lanthanide complex, Eu(tta3L (tta=2-thenoyltrifluoroacetonate, L = 4,5-pinene bipyridine, is used as gate insulating material to fabricate low-voltage pentacene field-effect transistors (FETs. The optimized gate insulator exhibits the excellent properties such as low leakage current density, low surface roughness, and high dielectric constant. When operated under a low voltage of −5 V, the pentacene FET devices show the attractive electrical performance, e.g. carrier mobility (μFET of 0.17 cm2 V−1 s−1, threshold voltage (Vth of −0.9 V, on/off current ratio of 5 × 103, and subthreshold slope (SS of 1.0 V dec−1, which is much better than that of devices obtained on conventional 300 nm SiO2 substrate (0.13 cm2 V−1 s−1, −7.3 V and 3.1 V dec−1 for μFET, Vth and SS value when operated at −30 V. These results indicate that this kind of high-κ organometallic lanthanide complex becomes a promising candidate as gate insulator for low-voltage organic FETs.

  16. Development of polymer concrete for dike insulation at LNG facilities: Phase 4, Low cost materials. Final report, September 1, 1987--April 30, 1990

    Energy Technology Data Exchange (ETDEWEB)

    Kukacka, L.E.

    1991-01-01

    Earlier GRI-sponsored work at Brookhaven National Laboratory has resulted in the development and utilization of insulating polymer concrete composites (IPC) as a means of reducing the evaporation rate of liquified natural gas in the event of a spill into a containment dike, thereby improving the safety at these sites. Although all of the required properties can be attained with the IPC, it was estimated that a low-cost replacement for the expensive organic binder would be necessary before use of the material would be cost-effective. In the current program, several latex modified cement formulations were evaluated and the most promising one identified. A mixture of two carboxylated styrene-butadiene latexes was selected for use in detailed laboratory property characterizations and a subsequent field evaluation. When compared to the properties of IPC, the latex-modified insulating materials display somewhat higher thermal conductivities, greater permeability to water, and reduced strength. However, these properties still meet most of the performance criteria, and the unit cost of the material is less than one-fifth that of IPC made with epoxy binders. When installed as a 0.75-in. thick overlay, material costs are estimated to be $1.00/ft{sup 2}.

  17. Development of ecological and economical super-insulations for various applications. Subproject 1: scientific development of ecological super-insulations for industrial application. Subproject 2: experimental synthesis and development of a pilot plant for continuously production and realisation of multilayer-insulation materials. Final report; Entwicklung oekologischer und wirtschaftlicher Super-Isolationen fuer vielfaeltige Anwendungen. Teilvorhaben 1: Wissenschaftliche Entwicklung oekologischer Super-Isolationen fuer industrielle Anwendungen. Teilvorhaben 2: Experimentelle Struktursynthese und Entwicklung einer Technikumsanlage zur kontinuierlichen Herstellung von Mehrschicht-Daemmstoffen. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Offermann, P.; Freudenberg, C.; Schenk, A.; Doerfel, A.; Hoffmann, G.; Roedel, H.; Schierz, C.; Hopf, W.

    2002-07-01

    Heat insulation materials are used in many applications with special tasks. Insulating materials like mineral wool, hard foams are used in civil engineering and for industrial insulation. Insulating materials from natural fibres are used in civil engineering on a small scale, too. In the clothing area are applied knitted fleece particularly for out-door-clothing in addition to non-woven made of synthetic polymers or wool. The aim of the project consists in the development of an insulating material with a very low heat conductivity and density as well as a multitude of degree of freedom to the structure and material parameters. A mathematical model has been developed for the determination of an optimised structure regarding to heat conductivity and density. The development was done by using the electrostatic flocking technology. After the material selection practical investigations have been done about the mode of function of the selected materials regarding their thermal insulation behaviour. A pilot plant for continuous production of the flocked material has been installed and tested. The result of this project is a very variable structure of insulating materials with excellent properties. The developed material is called Super-Insulation-Flock-Material (SIFM). Using defined structural parameters and skillfully selected materials it would be possible to get a heat conductivity between 0,027 W/mK and 0,30 W/mK. The density of these structures is between 10 kg/m{sup 3} and 20 kg/m{sup 3}. Structures with a density of only 7 kg/m{sup 3} are able to attend for applications without high mechanical demands. The Super-Insulation-Fock-Material is used in the clothing area and the technical sector. Sample products, e.g. a cold protective jacket, a jacket for fire fighters, insulation of airplanes as well as heat protective plates for the automotive industry, are found out. New fields for further applications of the Super-Insulation-Flock-Material result from the

  18. Construction of computational program of aging in insulating materials for searching reversed sequential test conditions to give damage equivalent to simultaneous exposure of heat and radiation

    International Nuclear Information System (INIS)

    Fuse, Norikazu; Homma, Hiroya; Okamoto, Tatsuki

    2013-01-01

    Two consecutive numerical calculations on degradation of polymeric insulations under thermal and radiation environment are carried out to simulate so-called reversal sequential acceleration test. The aim of the calculation is to search testing conditions which provide material damage equivalent to the case of simultaneous exposure of heat and radiation. At least following four parameters are needed to be considered in the sequential method; dose rate and exposure time in radiation, as well as temperature and aging time in heating. The present paper discusses the handling of these parameters and shows some trial calculation results. (author)

  19. 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.

  20. Extended defects in insulating MgAl{sub 2}O{sub 4} ceramic materials studied by PALS methods

    Energy Technology Data Exchange (ETDEWEB)

    Klym, H; Ingram, A; Shpotyuk, O; Filipecki, J; Hadzaman, I, E-mail: klymha@yahoo.com, E-mail: shpotyuk@novas.lviv.ua

    2010-11-15

    Extended positron-trapping defects in technological modified insulating nanoporous MgAl{sub 2}O{sub 4} ceramics are characterized by positron annihilation lifetime spectroscopy. The results are achieved using three-component fitting procedure with arbitrary lifetimes applied to treatment of measured spectra. Within this approach, the first component in the lifetime spectra reflects microstructure specificity of the spinel structure, the second component responsible to extended defects near intergranual boundaries and the third component correspond to ortho-positronium 'pick-off' decaying in nanopores of ceramics. It is shown that in ceramics of different technological modifications the same type of positron traps prevails.

  1. 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

  2. Reusable Surface Insulation

    Science.gov (United States)

    1997-01-01

    Advanced Flexible Reusable Surface Insulation, developed by Ames Research Center, protects the Space Shuttle from the searing heat that engulfs it on reentry into the Earth's atmosphere. Initially integrated into the Space Shuttle by Rockwell International, production was transferred to Hi-Temp Insulation Inc. in 1974. Over the years, Hi-Temp has created many new technologies to meet the requirements of the Space Shuttle program. This expertise is also used commercially, including insulation blankets to cover aircrafts parts, fire barrier material to protect aircraft engine cowlings and aircraft rescue fire fighter suits. A Fire Protection Division has also been established, offering the first suit designed exclusively by and for aircraft rescue fire fighters. Hi-Temp is a supplier to the Los Angeles City Fire Department as well as other major U.S. civil and military fire departments.

  3. Insulators for fusion applications

    International Nuclear Information System (INIS)

    1987-04-01

    Design studies for fusion devices and reactors have become more detailed in recent years and with this has come a better understanding of requirements and operating conditions for insulators in these machines. Ceramic and organic insulators are widely used for many components of fusion devices and reactors namely: radio frequency (RF) energy injection systems (BeO, Al 2 O 3 , Mg Al 2 O 4 , Si 3 N 4 ); electrical insulation for the torus structure (SiC, Al 2 O 3 , MgO, Mg Al 2 O 4 , Si 4 Al 2 O 2 N 6 , Si 3 N 4 , Y 2 O 3 ); lightly-shielded magnetic coils (MgO, MgAl 2 O 4 ); the toroidal field coil (epoxies, polyimides), neutron shield (B 4 C, TiH 2 ); high efficiency electrical generation; as well as the generation of very high temperatures for high efficiency hydrogen production processes (ZrO 2 and Al 2 O 3 - mat, graphite and carbon - felt). Timely development of insulators for fusion applications is clearly necessary. Those materials to be used in fusion machines should show high resistance to radiation damage and maintain their structural integrity. Now the need is urgent for a variety of radiation resistant materials, but much effort in these areas is required for insulators to be considered seriously by the design community. This document contains 14 papers from an IAEA meeting. It was the objective of this meeting to identify existing problems in analysing various situations of applications and requirements of electrical insulators and ceramics in fusion and to recommend strategies and different stages of implementation. This meeting was endorsed by the International Fusion Research Council

  4. Topological Insulator Nanowires and Nanoribbons

    KAUST Repository

    Kong, Desheng; Randel, Jason C.; Peng, Hailin; Cha, Judy J.; Meister, Stefan; Lai, Keji; Chen, Yulin; Shen, Zhi-Xun; Manoharan, Hari C.; Cui, Yi

    2010-01-01

    Recent theoretical calculations and photoemission spectroscopy measurements on the bulk Bi2Se3 material show that it is a three-dimensional topological insulator possessing conductive surface states with nondegenerate spins, attractive

  5. 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.

  6. Characteristics of MOSFETs fabricated in silicon-on-insulator material formed by high-dose oxygen ion implantation

    International Nuclear Information System (INIS)

    Lam, H.W.; Pinizzotto, R.F.; Yuan, H.T.; Bellavance, D.W.

    1981-01-01

    By implanting a dose of 6 x 10 17 cm -2 of 32 O 2 + at 300 keV into a silicon wafer, a buried oxide layer is formed. Crystallinity of the silicon layer above the buried oxide layer is maintained by applying a high (>200 0 C) substrate temperature during the ion implantation process. A two-step anneal cycle is found to be adequate to form the insulating buried oxide layer and to repair the implantation damage in the silicon layer on top of the buried oxide. A surface electron mobility as high as 710 cm 2 /Vs has been measured in n-channel MOSFETs fabricated in a 0.5 μm-thick epitaxial layer grown on the buried oxide wafer. A minimum subthreshold current of about 10 pA per micron of channel width at Vsub(DS)=2 V has been measured. (author)

  7. Partial discharge characteristics of polymer nanocomposite materials in electrical insulation: a review of sample preparation techniques, analysis methods, potential applications, and future trends.

    Science.gov (United States)

    Izzati, Wan Akmal; Arief, Yanuar Z; Adzis, Zuraimy; Shafanizam, Mohd

    2014-01-01

    Polymer nanocomposites have recently been attracting attention among researchers in electrical insulating applications from energy storage to power delivery. However, partial discharge has always been a predecessor to major faults and problems in this field. In addition, there is a lot more to explore, as neither the partial discharge characteristic in nanocomposites nor their electrical properties are clearly understood. By adding a small amount of weight percentage (wt%) of nanofillers, the physical, mechanical, and electrical properties of polymers can be greatly enhanced. For instance, nanofillers in nanocomposites such as silica (SiO2), alumina (Al2O3) and titania (TiO2) play a big role in providing a good approach to increasing the dielectric breakdown strength and partial discharge resistance of nanocomposites. Such polymer nanocomposites will be reviewed thoroughly in this paper, with the different experimental and analytical techniques used in previous studies. This paper also provides an academic review about partial discharge in polymer nanocomposites used as electrical insulating material from previous research, covering aspects of preparation, characteristics of the nanocomposite based on experimental works, application in power systems, methods and techniques of experiment and analysis, and future trends.

  8. An Analysis of the Thermal Conductivity of Composite Materials (CPC-30R/Charcoal from Sugarcane Bagasse Using the Hot Insulated Plate Technique

    Directory of Open Access Journals (Sweden)

    René Salgado-Delgado

    2016-01-01

    Full Text Available The production of new thermally insulating composite materials from solid residues such as charcoal from sugarcane bagasse (CSB is of great importance because it takes advantage of materials that might otherwise pollute the environment. Therefore, for this study, we obtained composite materials based on a portland cement (CPC-30R matrix and CSB particles with a 4 : 1 water-cement ratio and CSB concentrations of 5%, 10%, and 15% by weight. The thermal conductivities of these materials were characterized following ASTM guideline C177, their CSB morphological properties were analyzed using scanning electron microscopy (SEM, and their compositions were determined using energy-dispersive spectrometer (EDS. The results show that the composite materials have reduced thermal conductivities. The metallic oxide percentage composition of the CSB was also determined. It was observed that there was a reduction in thermal conductivity when CSB was used as compared to 100% CPC-30R, and the influence of the CSB concentration on thermal conductivity was measured.

  9. Results of the research on electrode and insulation wall material in fiscal 1977. Large scale technological development 'R and D on magneto hydrodynamic generation'; 1977 nendo denkyoku oyobi zetsuenheki zairyo ni kansuru kenkyu seika

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-06-01

    Results of research in fiscal 1977 were compiled concerning electrodes and insulation wall materials, the research conducted by the material working group of the magneto hydrodynamic (MHD) generation R and D liaison conference. Researches on trial manufacturing of duct materials for MHD generation were conducted for a Si{sub 3}N{sub 4}-MgO, Si{sub 3}N{sub 4}-Spinel, Spinel and Sialon based insulation wall material, MgO-BN based insulation wall material, tin oxide based electrode material, cold press ZrO{sub 2}-CeO{sub 2} and ZrO{sub 2}-Y{sub 2}O{sub 2} based electrode material, hot press hot hydrostatic pressure ZrO{sub 2}-CeO{sub 2} based electrode material, cermet based electrode material, etc. In the investigation and measurement of basic characteristics, these materials were put through various tests such as 1,300 degree C-300 hr-K{sub 2}SO{sub 4} immersion test, thermal shock resistance, thermal expansibility, oxidation resistance of oxide/nitride based materials. In addition, selection of materials for MHD generation, as well as the examination and degradation analysis of dynamic characteristics, was carried out by simulation of MHD generation, which provided data of various electrodes such as consumption, electrical characteristics (electrode lowering voltage, critical current, etc.) and thermal characteristics (surface temperature, heat flow velocity, etc.) (NEDO)

  10. Heat-insulating mortars for older buildings. Problem solutions for all kinds of building materials. Waermedaemmputze in der Altbausanierung. Problemloesungen auf allen Untergruenden

    Energy Technology Data Exchange (ETDEWEB)

    Bresch, C M

    1988-01-01

    The book is a guideline for the renovation and sanitation of outer walls with improved thermal insulation. Heat-insulating mortars are described, and machines and equipment for efficient roughcasting are listed. Subjects: Heat-insulating mortars; protective cover and thermal insulation; surfaces to be plastered (old brick walls, house fronts, wall cracks); renovation or sanitation; colours and structures; manual and mechanized roughcasting; calculations; an exemplary case of sanitation, solutions for constructional details; light-weight mortar; heat-insulating mortars in Austria. (HWJ).

  11. Integrated Multilayer Insulation

    Science.gov (United States)

    Dye, Scott

    2009-01-01

    Integrated multilayer insulation (IMLI) is being developed as an improved alternative to conventional multilayer insulation (MLI), which is more than 50 years old. A typical conventional MLI blanket comprises between 10 and 120 metallized polymer films separated by polyester nets. MLI is the best thermal- insulation material for use in a vacuum, and is the insulation material of choice for spacecraft and cryogenic systems. However, conventional MLI has several disadvantages: It is difficult or impossible to maintain the desired value of gap distance between the film layers (and consequently, it is difficult or impossible to ensure consistent performance), and fabrication and installation are labor-intensive and difficult. The development of IMLI is intended to overcome these disadvantages to some extent and to offer some additional advantages over conventional MLI. The main difference between IMLI and conventional MLI lies in the method of maintaining the gaps between the film layers. In IMLI, the film layers are separated by what its developers call a micro-molded discrete matrix, which can be loosely characterized as consisting of arrays of highly engineered, small, lightweight, polymer (typically, thermoplastic) frames attached to, and placed between, the film layers. The term "micro-molded" refers to both the smallness of the frames and the fact that they are fabricated in a process that forms precise small features, described below, that are essential to attainment of the desired properties. The term "discrete" refers to the nature of the matrix as consisting of separate frames, in contradistinction to a unitary frame spanning entire volume of an insulation blanket.

  12. Characterization of semi-insulating materials by photoinduced current transient spectroscopy: Fe doped INP for micro-optoelectronics and CdZnTe for nuclear detection

    International Nuclear Information System (INIS)

    Cherkaoui, K.

    1998-01-01

    The need of semi-insulating materials, of great quality, concerns various application domains. For instance, the very resistive substrates InP and CdZnTe are respectively adapted to the micro-optoelectronic circuits and to nuclear detectors. These two materials have been characterized by the thermal photoinduced current transient spectroscopy. The first part of this thesis is the defects analysis of annealing InP substrates, to understand the compensation process of this material. Two activation energy levels around 0,2 to 0,4 eV resulting from the thermal treatment have been detected. The iron omnipresence in the substrates, even undoped, has been noticed. It is then necessary to take into account the iron presence to understand the compensation process in these InP annealing substrates. the second part presents the study of the CdZnTe material, elaborated by the Bridgman method, to emphasize the defects leading to the decrease of the detector performances. The presence of three deep levels, near the forbidden band middle, is in relation with the detectors performances. (A.L.B.)

  13. Dielectric and Insulating Technology 2005 : Reviews & Forecasts

    Science.gov (United States)

    Okamoto, Tatsuki

    This article reports the state-of-art of TC-DEI ( Technical Committee of Dielectrics and Electrical Insulation of IEEJ) activites. The activiteis are basically based on the activites of 8-10 investigation committees under TC-DEI. Recent activites were categorized into three functions in this article and remarkable activity or trend for each category is mentioned as was done in the article of 2003. Thoese are activities on asset management (AI application and insulation diagnosis), activities on new insulating and functional materials (Nano composite) and activities on new insulation technology for power tansmission (high Tc superconducting cable insulation).

  14. Dielectric and Insulating Technology 2006 : Review & Forecast

    Science.gov (United States)

    Okamoto, Tatsuki

    This article reports the state-of-art of TC-DEI ( Technical Committee of Dielectrics and Electrical Insulation of IEEJ) activites. The activiteis are basically based on the activites of 8-10 investigation committees under TC-DEI. Recent activites were categorized into three functions in this article and remarkable activity or trend for each category is mentioned as was seen in the articles of 2005. Those are activities on asset management (AI application and insulation diagnosis), activities on new insulating and functional materials (Nano composite) and activities on new insulation technology for power tansmission (high Tc superconducting cable insulation).

  15. 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.

  16. Cryogenic foam insulation: Abstracted publications

    Science.gov (United States)

    Williamson, F. R.

    1977-01-01

    A group of documents were chosen and abstracted which contain information on the properties of foam materials and on the use of foams as thermal insulation at cryogenic temperatures. The properties include thermal properties, mechanical properties, and compatibility properties with oxygen and other cryogenic fluids. Uses of foams include applications as thermal insulation for spacecraft propellant tanks, and for liquefied natural gas storage tanks and pipelines.

  17. Masonry calendar 1989. A handbook on masonry, wall construction materials, sound, thermal and moisture insulation. Mauerwerk-Kalender 1989. Taschenbuch fuer Mauerwerk, Wandbaustoffe, Schall-, Waerme- und Feuchtigkeitsschutz

    Energy Technology Data Exchange (ETDEWEB)

    Funk, P [ed.

    1989-01-01

    The 1989 Masonry Calendar comprises the following sections and contibutions: Harmonisation of technical rules for brickwork construction on a European scale; fundamentals for brickwork dimensioning according to DIN 1053, part 2; exemplary calculations for the dimensioning of brick walls under compressive and shearing loads according to DIN 1053, part 2; calculation aids for brickwork dimensioning according to DIN 1053, part 2; dimensioning tables for reinforced brickwork of rectangular cross section; characteristic data of brickwork, bricks, and mortar; thermal insulation of brickwork; moisture protection problems in brickwork construction; noise abatement in brickwork construction; novel materials and designs in brickwork construction; characteristic data for calculating the thermal conductivity of building materials; regulations on construction, bricks, binders; further construction materials, testing standards, constructional physics, further standards and technical regulations for brickwork construction, with supplements; DGfM codes; work scaffolding; dwelling on brickwork construction; experiments on the seismic response of brickwork; supporting strength of brick walls under simultaneous horizontal and vertical stress; masonry cost calculation in the framework of overall construction cost calculation; bibliography and important addresses. (BR).

  18. Processing of insulators and semiconductors

    Science.gov (United States)

    Quick, Nathaniel R.; Joshi, Pooran C.; Duty, Chad Edward; Jellison, Jr., Gerald Earle; Angelini, Joseph Attilio

    2015-06-16

    A method is disclosed for processing an insulator material or a semiconductor material. The method includes pulsing a plasma lamp onto the material to diffuse a doping substance into the material, to activate the doping substance in the material or to metallize a large area region of the material. The method may further include pulsing a laser onto a selected region of the material to diffuse a doping substance into the material, to activate the doping substance in the material or to metallize a selected region of the material.

  19. Tank Insulation

    Science.gov (United States)

    1979-01-01

    For NASA's Apollo program, McDonnell Douglas Astronautics Company, Huntington Beach, California, developed and built the S-IVB, uppermost stage of the three-stage Saturn V moonbooster. An important part of the development task was fabrication of a tank to contain liquid hydrogen fuel for the stage's rocket engine. The liquid hydrogen had to be contained at the supercold temperature of 423 degrees below zero Fahrenheit. The tank had to be perfectly insulated to keep engine or solar heat from reaching the fuel; if the hydrogen were permitted to warm up, it would have boiled off, or converted to gaseous form, reducing the amount of fuel available to the engine. McDonnell Douglas' answer was a supereffective insulation called 3D, which consisted of a one-inch thickness of polyurethane foam reinforced in three dimensions with fiberglass threads. Over a 13-year development and construction period, the company built 30 tanks and never experienced a failure. Now, after years of additional development, an advanced version of 3D is finding application as part of a containment system for transporting Liquefied Natural Gas (LNG) by ship.

  20. Effects of the TiO2 high-k insulator material on the electrical characteristics of GaAs based Schottky barrier diodes

    Science.gov (United States)

    Zellag, S.; Dehimi, L.; Asar, T.; Saadoune, A.; Fritah, A.; Özçelik, S.

    2018-01-01

    The effects of the TiO2 high-k insulator material on Au/n-GaAs/Ti/Au Schottky barrier diodes have been studied by means of the numerical simulation and experimental results at room temperature. The Atlas-Silvaco-TCAD numerical simulator has been used to explain the behavior of different physical phenomena of Schottky diode. The experimental values of ideality factor, barrier height, and series resistance have been determined by using the various techniques such as Cheung's method, forward bias ln I- V and reverse capacitance-voltage behaviors. The experimental ideality factor and barrier height values have been found to be 4.14 and 0.585 eV for Au/n-GaAs/Ti/Au Schottky barrier diode and 4.00 and 0.548 eV for that structure with 16 nm thick TiO2 film and 3.92, 0.556 eV with 100 nm thick TiO2 film. The diodes show a non-ideal current-voltage behavior that of the ideality factor so far from unity. The extraction of N ss interface distribution profile as a function of E c -E ss is made using forward-bias I- V measurement by considering the bias dependence of ideality factor, the effective barrier height, and series resistance for Schottky barrier diodes. The N ss calculated values with consideration of the series resistance are lower than the calculated ones without series resistance. The current-voltage results of diodes reveal an abnormal increase in leakage current with an increase in thickness of high-k interfacial insulator layer. However, the simulation agrees in general with the experimental results.

  1. Development of insulating coatings for liquid metal blankets

    International Nuclear Information System (INIS)

    Malang, S.; Borgstedt, H.U.; Farnum, E.H.; Natesan, K.; Vitkovski, I.V.

    1994-07-01

    It is shown that self-cooled liquid metal blankets are feasible only with electrically insulating coatings at the duct walls. The requirements on the insulation properties are estimated by simple analytical models. Candidate insulator materials are selected based on insulating properties and thermodynamic consideration. Different fabrication technologies for insulating coatings are described. The status of the knowledge on the most crucial feasibility issue, the degradation of the resisivity under irradiation, is reviewed

  2. Heat insulating plates

    Energy Technology Data Exchange (ETDEWEB)

    Allan, J.A.F.

    1976-10-28

    Micro-porous insulation plates are dealt with, for example, how they are used in the insulation of heat storage devices. Since one side of such plates is exposed to a temperature of over 700/sup 0/C, a shrinkage of the glass texture of the covering can occur, which can exceed the shrinkage of the inner micro-porous material, so that cracks and splits in the high temperature side of the covering can come about. The task of the invention is to design the plate in such a way as to prevent this from happening. For this purpose the plate is provided, according to invention specifications, with flutes, waves, ribs, waffle or grid patterns and the covering is set into the recesses originating from this.

  3. 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.

  4. 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

  5. Method of manufacturing a thermally insulating body

    Energy Technology Data Exchange (ETDEWEB)

    McWilliams, J.A.; Morgan, D.E.; Jackson, J.D.

    1988-10-11

    A method of manufacturing a microporous thermally insulating body comprises mixing together a finely divided microporous insulating material such as silica aerogel or pyrogenic silica and a solid ammonia-generating compound in particulate form, and compressing the mixture to form a thermally insulating body. The ammonia-generating compound is dispersed evenly throughout the insulating material and may comprise, for example, ammonium carbonate, ammonium acetate or urea. Preferably, the ammonia-generating compound comprises a mixture of about one third by weight of ammonium carbonate and about two thirds by weight of ammonium bicarbonate together with a small proportion of magnesium oxide. Experiments are described which illustrate the manufacturing process. 6 tabs.

  6. Characterization of Metal-Insulator-Transition (MIT) Phase Change Materials (PCM) for Reconfigurable Components, Circuits, and Systems

    Science.gov (United States)

    2013-03-01

    material, the thin film may be showing a plastic response. Table 2 shows the Young’s modulus of an amorphous GeTe witness sample at a variety of...Nanoelectronics (RSM), Serdang, Malaysia , 2011. [19] K. Van Caekenberghe, "RF MEMS on the radar," IEEE Microwave Magazine, vol. 10, no. 6, pp. 99-116

  7. Common problems of acquisition of reference data on radiation reliability of structural electro insulating materials used in NPP electrical equipment

    International Nuclear Information System (INIS)

    Tyutnev, A.P.; Valeev, R.S.

    1993-01-01

    General principles of conducting accelerated radiation testings of electrotechnical products with regard to operation factors typical of NPPs are considered. Non-additivity of effect of these factors on the product and material parameters and parameter dependence on ionizing radiation dose rate are demonstrated

  8. Characterization of dielectric materials in thin layers for the development of S.O.I. (Silicon on Insulator) substrates

    International Nuclear Information System (INIS)

    Gruber, Olivier

    1999-01-01

    This thesis deals with the characterization of oxide layer placed inside S.O.I. substrates and submitted to irradiation. This type of material is used for the development of hardened electronic components, that is to say components able to be used in a radiative environment. The irradiation induces charges (electrons or holes) in the recovered oxide. A part of these charges is trapped which leads to changes of the characteristics of the electronic components made on these substrates. The main topic of this study is the characterization of trapping properties of recovered oxides and more particularly of 'Unibond' material carried out with a new fabrication process: the 'smart-cut' process. This work is divided into three parts: - study with one carrier: this case is limited to low radiation doses where is only observed holes trapping. The evolution of the physical and chemical properties of the 'Unibond' material recovered oxide has been revealed, this evolution being due to the fabrication process. - Study with two carriers: in this case, there is trapping of holes and electrons. This type of trapping is observed in the case of strong radiation doses. A new type of electrons traps has been identified with the 'Unibond' material oxide. The transport and the trapping of holes and electrons have been studied in the case of transient phenomena created by short radiative pulses. This study has been carried out using a new measurement method. - Study with three carriers: here are added to holes and electrons the protons introduced in the recovered oxide by the annealing under hydrogen. These protons are movable when they are submitted to the effect of an electric field and they induce a memory effect according to their position in the oxide. These different works show that the 'Unibond' material is a very good solution for the future development of S.O.I. (author) [fr

  9. Materiali acustici fonoisolanti e fonoassorbenti di origine vegetale - Acoustic materials of vegetable origin for sound absorption and sound insulation

    Directory of Open Access Journals (Sweden)

    Francesco Asdrubali

    2015-10-01

    Full Text Available I materiali acustici di origine vegetale possono rappresentare delle valide alternative sia dal punto di vista prestazionale che ambientale ai materiali sintetici e minerali, ma al momento attuale un esiguo numero di essi è già pronto da essere commercializzato. La presente memoria propone uno stato dell’arte su questa famiglia di materiali, fornendo le caratteristiche di fonoisolamento/assorbimento a partire dai materiali più diffusi fino a quelli meno convenzionali. Tali prodotti sono realizzati dagli scarti delle coltivazioni e delle aziende di trasformazione: ciò comporta un impatto ambientale basso se i materiali sono disponibili localmente e non in conflitto con colture alimentari. ------ Acoustic materials of vegetable origin can be a good alternative to traditional ones both from the technical and environmental point of view but very few of them are technologically mature enough to be commercialized. The present paper reports a state of the art of this family of materials, providing the acoustic characteristics starting from the most widespread and promising products to the unconventional ones. These products are realized using the residuals of the cultivation process or of the processing industry so their environmental impact is very low, if the raw materials are local and are not in contrast with food crops.

  10. Materials

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2009-02-01

    Full Text Available . It is generally included as part of a structurally insulated panel (SIP) where the foam is sandwiched between external skins of steel, wood or cement. Cement composites Cement bonded composites are an important class of building materials. These products... for their stone buildings, including the Egyptians, Aztecs and Inca’s. As stone is a very dense material it requires intensive heating to become warm. Rocks were generally stacked dry but mud, and later cement, can be used as a mortar to hold the rocks...

  11. FY 2000 report on the survey of the freon recovery/treatment technology for construction use heat insulating materials; 2000 nendo chosa hokokusho. Kenchiku yo dannetsuzai furon kaishu shori gijutsu chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-03-01

    An investigational study was made of the quantity of the specified freon remaining in the construction use heat insulating material, the rational method for the recovery/treatment, etc. As to the standardization of the method to analyze the remaining freon quantity, the tube furnace - GC method and the MS method were proposed, and the basic items that can be developed to JIS (Japanese Industrial Standard) were standardized. In the estimation of the remaining freon quantity, the actual state of the use of heat insulating materials was surveyed from the statistics on the start of construction work, survey of the heat insulating area in actual buildings and listening to heat insulation workers/cold store construction companies, etc. Further, the remaining quantity was analyzed of samples collected from various buildings nationwide and by years of completion. As a result, it was found out that, even in samples before 1995, HCFC is used in about 10% and that, in case of limiting to the specified freon (CFC), the freon remaining quantity was more than 1-4 wt% even after a lapse of 30 years. The paper arranged subjects on the freon recovery/treatment in each stage of the life cycle and the required conditions for technology/equipment. (NEDO)

  12. Materials colloquium `96: Thermal insulation coatings. Thermally insulating coating systems for heavy-duty structural components in aerospace engineering and energy engineering; Werkstoff-Kolloquium `96: Waermedaemmschichten. Waermeisolierende Schichtsysteme fuer hoechstbelastete Strukturbauteile in der Luft- und Raumfahrt sowie der Energietechnik

    Energy Technology Data Exchange (ETDEWEB)

    Peters, M.; Schulz, U.; Leushake, U.; Kaysser, W.A. [eds.

    1996-12-31

    The 15 contributions in this colloquium report document the current state of research and development in Germany in the field of thermally insulating layer structures for heavy-duty components like gas turbines. Five papers have been recorded separately in the ENERGY database. [Deutsch] Die 15 Beitraege in diesem Kolloquiumband dokumentieren den aktuellen Stand der Forschungs- und Entwicklungsarbeiten in Deutschland auf dem Gebiet der waermeisolierenden Schichtsysteme fuer hoechstbelastete Bauteile wie z.B. Gasturbinen. Fuer die Datenbank ENERGY wurden fuenf Artikel separat aufgenommen.

  13. Evaluation of stability of polymeric insulation materials in radiation fields and development of radiation stable PVC and polypropylene for medical devices

    International Nuclear Information System (INIS)

    Gonzalez, M.E.; Docters, A.S.

    1999-01-01

    Radiation stability of polypropylene and polyvinylchloride medical products of local origin was evaluated, establishing their functionality by appropriate methods. A device for a mechanical test of syringes and another device for puncture testing of plastic films were constructed and tested. Shelf-life anticipation of irradiated products was examined by treating to high doses and in other cases by storing irradiated products at high temperatures. In both cases negative results would anticipate no functionality for real time aged products. Radiation stability improvement was tried by incorporating light protectors and antioxidants into polypropylene homopolymer. A composition with added light protector was obtained that did not discolor and that kept mechanical stability during aging. Polyvinylchloride tubing was examined and found stable in comparison with imported materials. A non-discoloring product could not be obtained. Evaluation of local commercial polyvinylchloride insulations of wires similar to the wires used in the conveyor system of the Irradiation Facility of Ezeiza Atomic Center suggested that the limit of 50 % reduction in elongation to break in relation to control samples as an indication of failure is too conservative, because this limit was reached much earlier than the actual period of use of installed wires. (author)

  14. 5th Duisburg thermal insulation days. Fuenfte Duisburger Waermedaemm-Tage

    Energy Technology Data Exchange (ETDEWEB)

    Agst, J. (ed.)

    1989-01-01

    This volume contains 18 specialist lectures mainly about the problems of thermal insulation in industrial furnaces and facility engineering. Among the subjects are: formed parts, monolithic lining materials and fillers of vermiculite; pyro-block-modular systems for furnaces (of the company DYKO-Morgan Fasertechnik); microporous insulating materials (KAOWOOL); properties of lightweight refractory bricks; thermal insulation in induction furnaces; vacuum moulded parts in electric furnace engineering; high temperature insulating materials with ceramic fibres; microtherm insulating materials. (MM).

  15. Development of a cellulose-based insulating composite material for green buildings: Case of treated organic waste (paper, cardboard, hash)

    Science.gov (United States)

    Ouargui, Ahmed; Belouaggadia, Naoual; Elbouari, Abdeslam; Ezzine, Mohammed

    2018-05-01

    Buildings are responsible for 36% of the final energy consumption in Morocco [1-2], and a reduction of this energy consumption of buildings is a priority for the kingdom in order to reach its energy saving goals. One of the most effective actions to reduce energy consumption is the selection and development of innovative and efficient building materials [3]. In this work, we present an experimental study of the effect of adding treated organic waste (paper, cardboard, hash) on mechanical and thermal properties of cement and clay bricks. Thermal conductivity, specific heat and mechanical resistance were investigated in terms of content and size additives. Soaking time and drying temperature were also taken into account. The results reveal that thermal conductivity decreases as well in the case of the paper-cement mixture as that of the paper-clay and seems to stabilize around 40%. In the case of the composite paper-cement, it is found that, for an additives quantity exceeding 15%, the compressive strength exceeds the standard for the hollow non-load bearing masonry. However, the case of paper-clay mixture seems to give more interesting results, related to the compressive strength, for a mass composition of 15% in paper. Given the positive results achieved, it seems possible to use these composites for the construction of walls, ceilings and roofs of housing while minimizing the energy consumption of the building.

  16. Ultra-low thermal conductivities of hot-pressed attapulgite and its potential as thermal insulation material

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yuan; Ren, Zhifeng, E-mail: bohr123@163.com, E-mail: zren@uh.edu [Department of Physics and TcSUH, University of Houston, Houston, Texas 77204 (United States); Wang, Xiuzhang [Department of Physics and TcSUH, University of Houston, Houston, Texas 77204 (United States); Hubei Key Laboratory of Pollutant Analysis and Reuse Technology and School of Physics and Electronic Science, Hubei Normal University, Huangshi, Hubei 435002 (China); Wang, Yumei [Department of Physics and TcSUH, University of Houston, Houston, Texas 77204 (United States); Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Tang, Zhongjia; Makarenko, Tatyana; Guloy, Arnold [Department of Chemistry, University of Houston, Houston, Texas 77204 (United States); Zhang, Qinyong, E-mail: bohr123@163.com, E-mail: zren@uh.edu [Center for Advanced Materials and Energy, Xihua University, Chengdu, Sichuan 610039 (China)

    2016-03-07

    In the past, there have been very few reports on thermal properties of attapulgite which is a widely used clay mineral. In this work, we report on extremely low thermal conductivities in attapulgite samples synthesized by hot-pressing. Attapulgite powder was hot-pressed at different temperatures into bulk samples, and a systematic study was conducted on the microstructures and thermal properties. Differential scanning calorimetry analysis shows that hot-pressing induces a rapid dehydration of the attapulgite powders. X-ray diffraction data and scanning/transmission electron microscopy reveal that the hot-pressed attapulgite features high porosity and complex microstructures, including an amorphous phase. As a result, the hot-pressed attapulgite exhibits thermal conductivity less than 2.5 W m{sup −1} K{sup −1} up to 600 °C. For one sample with porosity of 45.7%, the thermal conductivity is as low as 0.34 W m{sup −1} K{sup −1} at 50 °C. This suggests the potential of hot-pressed attapulgite as a candidate for thermal barrier materials.

  17. Dielectric and Insulating Technology 2004 : Review & Forecast

    Science.gov (United States)

    Okamoto, Tatsuki

    This article reports the state-of-art of DEIS activites. DEIS activiteis are basically based on the activites of 8-10 investigation committees’ under DEIS committee. Recent DEIS activites are categlized into three functions in this article and remarkable activity or trend of each category is mentioned. Those are activities on insulation diagnosis (AI application and asset management), activities on new insulation technology for power tansmission (high Tc super conducting cable insulation and all solid sinulated substation), and activities on new insulating materials (Nanocomposite).

  18. Process insulation. Isolation thermique des equipements

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    A manual is presented to assist managers and operating personnel to recognize industrial energy management opportunities, and provides mathematical equations, general information on proven techniques and technology, and examples. It deals with process insulation, focusing on the insulation of mechanical systems such as piping, process vessels, equipment, and ductwork. The manual describes the effects of insulation materials; commonly encountered types of insulation, coverings and protective finishes as well as common applications; energy management opportunities, divided into housekeeping, low cost, and retrofit; and includes worked examples of each. Includes glossary. 17 figs., 8 tabs.

  19. (H)-FCKW foamed insulating materials in the building industry in Germany. Estimation of the potential emissions up to the year 2010; (H)-FCKW-geschaeumte Daemmstoffe im Bauwesen in Deutschland. Schaetzung der potentiellen Emissionen bis zum Jahr 2010

    Energy Technology Data Exchange (ETDEWEB)

    Obernosterer, Richard [Ressourcen Management Agentur GmbH, Villach (Austria)

    2012-09-15

    CFCs and HCFCs are controlled substances under European Regulation (EC) No. 1005/2009. Article 22 of that Regulation provides that controlled substances contained in certain products (e.g. insulating materials) must be recovered, if technically and economically feasible, or be destroyed without prior recovery. Annex VII lists specific technologies for destruction, recycling or reclamation. In Germany, the use of (H)CFCs in insulating materials has been prohibited since 1995 (R 11 and R 12) and 2000 (R 22). At European level, use of HCFCs (141b and 142b) has been banned since 2002 mainly in the production of extruded polystyrene rigid foam and since 2003 in the production of polyurethane foams. Few data have become available to date on the amounts of (H)CFCs produced and banked up to the time the prohibitions went into effect. The present report therefore provides details on the amounts of (H)CFC-containing insulating materials installed in Germany and estimates the quantities of (H)CFCs still present in them. The study focuses on rigid XPS foam and rigid PU foam used in the construction sector, due to the original objective of the study and the quantitative significance of these foams. XPS insulating foams: XPS panels were assumed to have an average density of 33 kg/m3. Based on annual foam use (volume), density, the market shares of the blowing agents, and blowing agent content in the foam, the annual increase in banked amounts of blowing agents was estimated. Annual fugitive losses were deducted from those banks, specific to the relevant products and blowing agents. As result a bank of approximately 43.7 kt or 15 000 t-ODP was estimated for Germany in 2009. PU insulating foams: Based on annual foam use (volume), density (assumed to be 41 kg/m3 for PU sandwich panels and 33 kg/m3 for other PU products), the market shares of the blowing agents, and blowing agent content in the foam, the annual increase in banked amounts of blowing agents was estimated. Annual

  20. ASRM case insulation design and development

    Science.gov (United States)

    Bell, Matthew S.; Tam, William F. S.

    1992-10-01

    This paper describes the achievements made on the Advanced Solid Rocket Motor (ASRM) case insulation design and development program. The ASRM case insulation system described herein protects the metal case and joints from direct radiation and hot gas impingement. Critical failure of solid rocket systems is often traceable to failure of the insulation design. The wide ranging accomplishments included the development of a nonasbestos insulation material for ASRM that replaced the existing Redesigned Solid Rocket Motor (RSRM) asbestos-filled nitrile butadiene rubber (NBR) along with a performance gain of 300 pounds, and improved reliability of all the insulation joint designs, i.e., segmented case joint, case-to-nozzle and case-to-igniter joint. The insulation process development program included the internal stripwinding process. This process advancement allowed Aerojet to match to exceed the capability of other propulsion companies.

  1. 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...

  2. The inaccuracy of heat transfer characteristics for non-insulated and insulated spherical containers neglecting the influence of heat radiation

    International Nuclear Information System (INIS)

    Wong, King-Leung; Salazar, Jose Luis Leon; Prasad, Leo; Chen, Wen-Lih

    2011-01-01

    In this investigation, the differences of heat transfer characteristics for insulated and non-insulated spherical containers between considering and neglecting the influence of heat radiation are studied by the simulations in some practical situations. It is found that the heat radiation effect cannot be ignored in conditions of low ambient convection heat coefficients (such ambient air) and high surface emissivities, especially for the non-insulated and thin insulated cases. In most practical situations when ambient temperature is different from surroundings temperature and the emissivity of insulation surface is different from that of metal wall surface, neglecting heat radiation will result in inaccurate insulation effect and heat transfer errors even with very thick insulation. However, the insulation effect considering heat radiation will only increase a very small amount after some dimensionless insulated thickness (such insulation thickness/radius ≥0.2 in this study), thus such dimensionless insulated thickness can be used as the optimum thickness in practical applications. Meanwhile, wrapping a material with low surface emissivity (such as aluminum foil) around the oxidized metal wall or insulation layer (always with high surface emissivity) can achieve very good insulated effect for the non-insulated or thin insulated containers.

  3. Modeling of Dynamic Responses in Building Insulation

    Directory of Open Access Journals (Sweden)

    Anna Antonyová

    2015-10-01

    Full Text Available In this research a measurement systemwas developedfor monitoring humidity and temperature in the cavity between the wall and the insulating material in the building envelope. This new technology does not disturb the insulating material during testing. The measurement system can also be applied to insulation fixed ten or twenty years earlier and sufficiently reveals the quality of the insulation. A mathematical model is proposed to characterize the dynamic responses in the cavity between the wall and the building insulation as influenced by weather conditions.These dynamic responses are manifested as a delay of both humidity and temperature changes in the cavity when compared with the changes in the ambient surrounding of the building. The process is then modeled through numerical methods and statistical analysis of the experimental data obtained using the new system of measurement.

  4. Topological insulators fundamentals and perspectives

    CERN Document Server

    Ortmann, Frank; Valenzuela, Sergio O

    2015-01-01

    There are only few discoveries and new technologies in physical sciences that have the potential to dramatically alter and revolutionize our electronic world. Topological insulators are one of them. The present book for the first time provides a full overview and in-depth knowledge about this hot topic in materials science and condensed matter physics. Techniques such as angle-resolved photoemission spectrometry (ARPES), advanced solid-state Nuclear Magnetic Resonance (NMR) or scanning-tunnel microscopy (STM) together with key principles of topological insulators such as spin-locked electronic

  5. Thermal insulation system design and fabrication specification (nuclear) for the Clinch River Breeder Reactor plant

    International Nuclear Information System (INIS)

    1978-01-01

    This specification defines the design, analysis, fabrication, testing, shipping, and quality requirements of the Insulation System for the Clinch River Breeder Reactor Plant (CRBRP), near Oak Ridge, Tennessee. The Insulation System includes all supports, convection barriers, jacketing, insulation, penetrations, fasteners, or other insulation support material or devices required to insulate the piping and equipment cryogenic and other special applications excluded. Site storage, handling and installation of the Insulation System are under the cognizance of the Purchaser

  6. Vacuum-insulated catalytic converter

    Science.gov (United States)

    Benson, David K.

    2001-01-01

    A catalytic converter has an inner canister that contains catalyst-coated substrates and an outer canister that encloses an annular, variable vacuum insulation chamber surrounding the inner canister. An annular tank containing phase-change material for heat storage and release is positioned in the variable vacuum insulation chamber a distance spaced part from the inner canister. A reversible hydrogen getter in the variable vacuum insulation chamber, preferably on a surface of the heat storage tank, releases hydrogen into the variable vacuum insulation chamber to conduct heat when the phase-change material is hot and absorbs the hydrogen to limit heat transfer to radiation when the phase-change material is cool. A porous zeolite trap in the inner canister absorbs and retains hydrocarbons from the exhaust gases when the catalyst-coated substrates and zeolite trap are cold and releases the hydrocarbons for reaction on the catalyst-coated substrate when the zeolite trap and catalyst-coated substrate get hot.

  7. Recent Progress in Electrical Insulation Techniques for HTS Power Apparatus

    Science.gov (United States)

    Hayakawa, Naoki; Kojima, Hiroki; Hanai, Masahiro; Okubo, Hitoshi

    This paper describes the electrical insulation techniques at cryogenic temperatures, i.e. Cryodielectrics, for HTS power apparatus, e.g. HTS power transmission cables, transformers, fault current limiters and SMES. Breakdown and partial discharge characteristics are discussed for different electrical insulation configurations of LN2, sub-cooled LN2, solid, vacuum and their composite insulation systems. Dynamic and static insulation performances with and without taking account of quench in HTS materials are also introduced.

  8. Using of Aerogel to Improve Thermal Insulating Properties of Windows

    Science.gov (United States)

    Valachova, Denisa; Zdrazilova, Nada; Panovec, Vladan; Skotnicova, Iveta

    2018-06-01

    For the best possible thermal-technical properties of building structures it is necessary to use materials with very low thermal conductivity. Due to the increasing thermal-technical requirements for building structures, the insulating materials are developed. One of the modern thermal insulating materials is so-called aerogel. Unfortunately, this material is not used in the field of external thermal insulation composite systems because of its price and its properties. The aim of this paper is to present possibilities of using this insulating material in the civil engineering - specifically a usage of aerogel in the production of windows.

  9. Periodic thermal response of multi-layer walls in a building. Materials of different types used for insulation, both internal and external

    Energy Technology Data Exchange (ETDEWEB)

    Elchinger, M F; Martin, C; Fauchais, P [UER des Sciences, Limoges (France)

    1982-05-01

    The authors analyze the temperature distribution in a wall built of several layers, heated on the inside, and whose outside wall temperatures exhibit a sine distribution: development of a simulation program and validation by comparison with experimental results. They determine the influence of the positioning and thickness of the insulation, the heat flux required to keep the inside surface of a 3, 4 or 5-layer wall at a fixed temperature, and make a comparison between heavy walls and light-weight structure walls. Finally, the study concludes with the determination of the most interesting insulation (external) for slack periods, night and weekend.

  10. An experimental study on thermal properties of composite insulation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Gyoung-Seok [Building and Urban Research Department, Korea Institute of Construction Technology, 2311 Daehwa-Dong, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do 411-712 (Korea); College of Architecture, Hanyang University, 17, Hangdang-Dong, Sungdong-Gu, Seoul 133-791 (Korea); Kang, Jae-Sik; Jeong, Young-Sun; Lee, Seung-Eon [Building and Urban Research Department, Korea Institute of Construction Technology, 2311 Daehwa-Dong, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do 411-712 (Korea); Sohn, Jang-Yeul [College of Architecture, Hanyang University, 17, Hangdang-Dong, Sungdong-Gu, Seoul 133-791 (Korea)

    2007-04-01

    In accordance with the insulation standards reinforced since 2001 and the compulsory standards on floor impact sound insulation that have been enforced since 2004, insulation materials for actual buildings have been converted to composite materials and new insulation materials have been released in the market. However, Korea is lagging behind the world in fundamental experimental studies and resources. In case of some composite insulation materials, there also have been problems of distorted performance occurring as a result of tests being conducted without having verification and evaluation on the accuracy and inaccuracy of such tests. Therefore, this study grasped the thermal properties of composite insulation materials using thermal conductivity test equipment by heat flux method, and performed quantitative evaluation on the measurement precision and uncertainty of composite materials. (author)

  11. Propagation Characteristics of Multilayer Hybrid Insulator-Metal-Insulator and Metal-Insulator-Metal Plasmonic Waveguides

    Directory of Open Access Journals (Sweden)

    M. Talafi Noghani

    2014-02-01

    Full Text Available Propagation characteristics of symmetrical and asymmetrical multilayer hybrid insulator-metal-insulator (HIMI and metal-insulator-metal (HMIM plasmonic slab waveguides are investigated using the transfer matrix method. Propagation length (Lp and spatial length (Ls are used as two figures of merit to qualitate the plasmonic waveguides. Symmetrical structures are shown to be more performant (having higher Lp and lower Ls, nevertheless it is shown that usage of asymmetrical geometry could compensate for the performance degradation in practically realized HIMI waveguides with different substrate materials. It is found that HMIM slab waveguide could support almost long-range subdiffraction plasmonic modes at dimensions lower than the spatial length of the HIMI slab waveguide.

  12. Economically optimal thermal insulation

    Energy Technology Data Exchange (ETDEWEB)

    Berber, J.

    1978-10-01

    Exemplary calculations to show that exact adherence to the demands of the thermal insulation ordinance does not lead to an optimal solution with regard to economics. This is independent of the mode of financing. Optimal thermal insulation exceeds the values given in the thermal insulation ordinance.

  13. Electrical insulator requirements for mirror fusion reactors

    International Nuclear Information System (INIS)

    Condit, R.H.; Van Konynenburg, R.A.

    1977-01-01

    The requirements for mirror fusion electrical insulators are discussed. Insulators will be required at the neutral beam injectors, injector power supplies, direct converters, and superconducting magnets. Insulators placed at the neutral beam injectors will receive the greatest radiation exposure, 10 14 to 10 16 neutrons/m 2 .s and 0.3 to 3 Gy/s (10 5 to 10 6 R/h) of gamma rays, with shielding. Direct converter insulators may receive the highest temperature (up to 1300 0 K), but low voltage holding requirements. Insulators made from organic materials (e.g., plastics) for the magnet coils may be satisfactory. Immediate conductivity increases of all insulators result from gamma irradiation. With an upper limit to gamma flux exposures of 300 Gy/s in a minimally shielded region, the conductivity could reach 10 -6 S/m. Damage from neutron irradiation may not be serious during several years' exposure. Surface changes in ceramics at the neutral beam injector may be serious. The interior of the injector will contain atomic hydrogen, and sputtering may transfer material away from or onto the ceramic insulators. Unknown and potentially damaging interactions between irradiation, electric fields, temperature gradients, cycling of temperature, surface and joint reactions, sputtering, polarization, and electrotransport in the dielectrics are of concern. Materials research to deal with these problems is needed

  14. Polyimide Foams Offer Superior Insulation

    Science.gov (United States)

    2012-01-01

    At Langley Research Center, Erik Weiser and his colleagues in the Advanced Materials and Processing Branch were working with a new substance for fabricating composites for use in supersonic aircraft. The team, however, was experiencing some frustration. Every time they tried to create a solid composite from the polyimide (an advanced polymer) material, it bubbled and foamed. It seemed like the team had reached a dead end in their research - until they had another idea. "We said, This isn t going to work for composites, but maybe we could make a foam out of it," Weiser says. "That was kind of our eureka moment, to see if we could go in a whole other direction. And it worked." Weiser and his colleagues invented a new kind of polyimide foam insulation they named TEEK. The innovation displayed a host of advantages over existing insulation options. Compared to other commercial foams, Weiser explains, polyimide foams perform well across a broad range of temperatures, noting that the NASA TEEK foams provide effective structural insulation up to 600 F and down to cryogenic temperatures. The foam does not burn or off-gas toxic fumes, and even at -423 F - the temperature of liquid hydrogen - the material stays flexible. The inventors could produce the TEEK foam at a range of densities, from 0.5 pounds per cubic foot up to 20 pounds per cubic foot, making the foam ideal for a range of applications, including as insulation for reusable launch vehicles and for cryogenic tanks and lines. They also developed a unique, friable balloon format for manufacturing the foam, producing it as hollow microspheres that allowed the foam to be molded and then cured into any desired shape - perfect for insulating pipes of different sizes and configurations. The team s originally unplanned invention won an "R&D 100" award, and a later form of the foam, called LaRC FPF-44 (Spinoff 2009), was named "NASA Invention of the Year" in 2007.

  15. Excitons in insulators

    International Nuclear Information System (INIS)

    Grasser, R.; Scharmann, A.

    1983-01-01

    This chapter investigates absorption, reflectivity, and intrinsic luminescence spectra of free and/or self-trapped (localized) excitons in alkali halides and rare gas solids. Introduces the concepts underlying the Wannier-Mott and Frenkel exciton models, two extreme pictures of an exciton in crystalline materials. Discusses the theoretical and experimental background; excitons in alkali halides; and excitons in rare gas solids. Shows that the intrinsic optical behavior of wide gap insulators in the range of the fundamental absorption edge is controlled by modified Wannier-Mott excitons. Finds that while that alkali halides only show free and relaxed molecular-like exciton emission, in rare gas crystals luminescence due to free, single and double centered localized excitons is observed. Indicates that the simultaneous existence of free and self-trapped excitons in these solid requires an energy barrier for self-trapping

  16. Built-in unit with short-circuit insulation for hermetic cable ducts

    International Nuclear Information System (INIS)

    Tschacher, B.; Gurr, W.; Kusserow, J.; Katzmarek, W.

    1984-01-01

    The invention concerns a built-in unit with short-circuit insulation for hermetic cable ducts, especially for containments of nuclear power reactors. The short-circuit insulation is achieved by an insulation plate made from radiation-resistant insulating materials of high mechanical strength

  17. Slab edge insulating form system and methods

    Science.gov (United States)

    Lee, Brain E [Corral de Tierra, CA; Barsun, Stephan K [Davis, CA; Bourne, Richard C [Davis, CA; Hoeschele, Marc A [Davis, CA; Springer, David A [Winters, CA

    2009-10-06

    A method of forming an insulated concrete foundation is provided comprising constructing a foundation frame, the frame comprising an insulating form having an opening, inserting a pocket former into the opening; placing concrete inside the foundation frame; and removing the pocket former after the placed concrete has set, wherein the concrete forms a pocket in the placed concrete that is accessible through the opening. The method may further comprise sealing the opening by placing a sealing plug or sealing material in the opening. A system for forming an insulated concrete foundation is provided comprising a plurality of interconnected insulating forms, the insulating forms having a rigid outer member protecting and encasing an insulating material, and at least one gripping lip extending outwardly from the outer member to provide a pest barrier. At least one insulating form has an opening into which a removable pocket former is inserted. The system may also provide a tension anchor positioned in the pocket former and a tendon connected to the tension anchor.

  18. Insulation systems of the building construtions

    Directory of Open Access Journals (Sweden)

    Rumiantcev Boris

    2016-01-01

    Full Text Available Constructions of the exterior insulation and decoration combines materials of different functionality and constructive solutions allows to these materials to demonstrate their efficiency to the great extent. Fire safety of buildings is mandatory requirement for building systems. Some insulating material may belong to the group of combustible, but their use in structures so as to minimize the risk of fire. On the other hand, there are special designs, in which non-flammable insulation acts as a flame retardant barrier. In the article carried systematization of construction systems used in the flat and pitched roof during the insulation and wall covering and facades. Taking into account the experience of leading firms were considered the application features of using exterior finish systems: construction solutions, requirements for materials and recommendations about the installation these systems.The article deals with the construction ventilated roofing system of two types: flat roof and pitched roof seam. In the first case, the ventilation system is created using milled insulation boards in the second - by a ventilated gap. In both cases the natural convection of air in the air cavities. Ensuring operational stability insulation is laid on the stages of production of heat-insulating materials. It is important: firstly responsible execution of all process operations associated with providing regulatory properties of materials and secondly, the performance of additional operations associated with the produc-tion of materials, working in a specific design. An example of a material whose properties can modify for a particular application, are milled mineral wool (with air channels for systems of ventilated flat roof.

  19. On effective holographic Mott insulators

    Energy Technology Data Exchange (ETDEWEB)

    Baggioli, Matteo; Pujolàs, Oriol [Institut de Física d’Altes Energies (IFAE), Universitat Autònoma de Barcelona,The Barcelona Institute of Science and Technology,Campus UAB, 08193 Bellaterra (Barcelona) (Spain)

    2016-12-20

    We present a class of holographic models that behave effectively as prototypes of Mott insulatorsmaterials where electron-electron interactions dominate transport phenomena. The main ingredient in the gravity dual is that the gauge-field dynamics contains self-interactions by way of a particular type of non-linear electrodynamics. The electrical response in these models exhibits typical features of Mott-like states: i) the low-temperature DC conductivity is unboundedly low; ii) metal-insulator transitions appear by varying various parameters; iii) for large enough self-interaction strength, the conductivity can even decrease with increasing doping (density of carriers) — which appears as a sharp manifestation of ‘traffic-jam’-like behaviour; iv) the insulating state becomes very unstable towards superconductivity at large enough doping. We exhibit some of the properties of the resulting insulator-superconductor transition, which is sensitive to the momentum dissipation rate in a specific way. These models imply a clear and generic correlation between Mott behaviour and significant effects in the nonlinear electrical response. We compute the nonlinear current-voltage curve in our model and find that indeed at large voltage the conductivity is largely reduced.

  20. On effective holographic Mott insulators

    International Nuclear Information System (INIS)

    Baggioli, Matteo; Pujolàs, Oriol

    2016-01-01

    We present a class of holographic models that behave effectively as prototypes of Mott insulatorsmaterials where electron-electron interactions dominate transport phenomena. The main ingredient in the gravity dual is that the gauge-field dynamics contains self-interactions by way of a particular type of non-linear electrodynamics. The electrical response in these models exhibits typical features of Mott-like states: i) the low-temperature DC conductivity is unboundedly low; ii) metal-insulator transitions appear by varying various parameters; iii) for large enough self-interaction strength, the conductivity can even decrease with increasing doping (density of carriers) — which appears as a sharp manifestation of ‘traffic-jam’-like behaviour; iv) the insulating state becomes very unstable towards superconductivity at large enough doping. We exhibit some of the properties of the resulting insulator-superconductor transition, which is sensitive to the momentum dissipation rate in a specific way. These models imply a clear and generic correlation between Mott behaviour and significant effects in the nonlinear electrical response. We compute the nonlinear current-voltage curve in our model and find that indeed at large voltage the conductivity is largely reduced.

  1. Silicon on insulator self-aligned transistors

    Science.gov (United States)

    McCarthy, Anthony M.

    2003-11-18

    A method for fabricating thin-film single-crystal silicon-on-insulator (SOI) self-aligned transistors. Standard processing of silicon substrates is used to fabricate the transistors. Physical spaces, between the source and gate, and the drain and gate, introduced by etching the polysilicon gate material, are used to provide connecting implants (bridges) which allow the transistor to perform normally. After completion of the silicon substrate processing, the silicon wafer is bonded to an insulator (glass) substrate, and the silicon substrate is removed leaving the transistors on the insulator (glass) substrate. Transistors fabricated by this method may be utilized, for example, in flat panel displays, etc.

  2. 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.

  3. Grandstand view of phenolic foam insulation

    Energy Technology Data Exchange (ETDEWEB)

    1987-03-01

    Stadium Insulation Ltd, manufacture pipe sections, tank and vessel insulation products in Lowphen, polyisocyanurate, polyurethane foams and expanded polystyrene, though for certain specialist applications, cork is still employed in small quantities. Currently the emphasis is very much on Lowphen, the company's range of pipe sections based on phenolic foam. The company's manufacturing and marketing effort reflects the increasing market trend towards the use of insulating material capable of withstanding higher temperatures, and phenolic foam neatly satisfies the demand since it is capable of use at temperatures up to 140/sup 0/C. Moreover, phenolic foam has the lowest K value at 0.02W/m/sup 0/C of any of the currently available range of insulating materials, and while the product is slightly more expensive than alternatives such as polyisocyanurate and polyurethane, its high performance offsets that premium.

  4. Airflow Resistance of Loose-Fill Mineral Fiber Insulations in Retrofit Applications

    Energy Technology Data Exchange (ETDEWEB)

    Schumacher, C. J. [Building Science Laboratories, Waterloo, ON (Canada); Fox, M. J. [Building Science Laboratories, Waterloo, ON (Canada); Lstiburek, J. [Building Science Corporation, Westford, MA (United States)

    2015-02-01

    This report expands on Building America Report 1109 by applying the experimental apparatus and test method to dense-pack retrofit applications using mineral fiber insulation materials. Three fiber glass insulation materials and one stone wool insulation material were tested, and the results compared to the cellulose results from the previous study.

  5. Airflow Resistance of Loose-Fill Mineral Fiber Insulations in Retrofit Applications

    Energy Technology Data Exchange (ETDEWEB)

    Schumacher, C. J. [Building Science Labs., Waterloo, ON (Canada); Fox, M. J. [Building Science Labs., Waterloo, ON (Canada); Lstiburek, J. [Building Science Corporation, Westford, MA (United States)

    2015-02-01

    This report expands on Building America Report 1109 by applying the experimental apparatus and test method to dense-pack retrofit applications using mineral fiber insulation materials. Three (3) fiber glass insulation materials and one (1) stone wool insulation material were tested, and the results compared to the cellulose results from the previous study.

  6. 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.

  7. Status of surface conduction in topological insulators

    International Nuclear Information System (INIS)

    Barua, Sourabh; Rajeev, K. P.

    2014-01-01

    In this report, we scrutinize the thickness dependent resistivity data from the recent literature on electrical transport measurements in topological insulators. A linear increase in resistivity with increase in thickness is expected in the case of these materials since they have an insulating bulk and a conducting surface. However, such a trend is not seen in the resistivity versus thickness data for all the cases examined, except for some samples, where it holds for a range of thickness

  8. Design of Chern insulating phases in honeycomb lattices

    Science.gov (United States)

    Pickett, Warren E.; Lee, Kwan-Woo; Pentcheva, Rossitza

    2018-06-01

    The search for robust examples of the magnetic version of topological insulators, referred to as quantum anomalous Hall insulators or simply Chern insulators, so far lacks success. Our groups have explored two distinct possibilities based on multiorbital 3d oxide honeycomb lattices. Each has a Chern insulating phase near the ground state, but materials parameters were not appropriate to produce a viable Chern insulator. Further exploration of one of these classes, by substituting open shell 3d with 4d and 5d counterparts, has led to realistic prediction of Chern insulating ground states. Here we recount the design process, discussing the many energy scales that are active in participating (or resisting) the desired Chern insulator phase.

  9. 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

  10. 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

  11. Joint China-United States Report for Year 1 Insulation Materials and Systems Project Area Clean Energy Research Center Building Energy Efficiency (CERC-BEE)

    Energy Technology Data Exchange (ETDEWEB)

    Stovall, Therese K [ORNL; Biswas, Kaushik [ORNL; Song, Bo [China Academy of Building Research; Zhang, Sisi [China Academy of Building Research

    2012-08-01

    In November of 2009, the presidents of China and the U.S. announced the establishment of the Clean Energy Research Center (CERC). This broad research effort is co-funded by both countries and involves a large number of research centers and universities in both countries. One part of this program is focused on improving the energy efficiency of buildings. One portion of the CERC-BEE was focused on building insulation systems. The research objective of this effort was to Identify and investigate candidate high performance fire resistant building insulation technologies that meet the goal of building code compliance for exterior wall applications in green buildings in multiple climate zones. A Joint Work Plan was established between researchers at the China Academy of Building Research and Oak Ridge National Laboratory. Efforts in the first year under this plan focused on information gathering. The objective of this research program is to reduce building energy use in China via improved building insulation technology. In cold regions in China, residents often use inefficient heating systems to provide a minimal comfort level within inefficient buildings. In warmer regions, air conditioning has not been commonly used. As living standards rise, energy consumption in these regions will increase dramatically unless significant improvements are made in building energy performance. Previous efforts that defined the current state of the built environment in China and in the U.S. will be used in this research. In countries around the world, building improvements have typically followed the implementation of more stringent building codes. There have been several changes in building codes in both the U.S. and China within the last few years. New U.S. building codes have increased the amount of wall insulation required in new buildings. New government statements from multiple agencies in China have recently changed the requirements for buildings in terms of energy efficiency and

  12. Sound Insulation between Dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2011-01-01

    Regulatory sound insulation requirements for dwellings exist in more than 30 countries in Europe. In some countries, requirements have existed since the 1950s. Findings from comparative studies show that sound insulation descriptors and requirements represent a high degree of diversity...... and initiate – where needed – improvement of sound insulation of new and existing dwellings in Europe to the benefit of the inhabitants and the society. A European COST Action TU0901 "Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions", has been established and runs...... 2009-2013. The main objectives of TU0901 are to prepare proposals for harmonized sound insulation descriptors and for a European sound classification scheme with a number of quality classes for dwellings. Findings from the studies provide input for the discussions in COST TU0901. Data collected from 24...

  13. Electrical breakdown studies with Mycalex insulators

    International Nuclear Information System (INIS)

    Waldron, W.; Greenway, W.; Eylon, S.; Henestroza, E.; Yu, S.

    2003-01-01

    Insulating materials such as alumina and glass-bonded mica (Mycalex) are used in accelerator systems for high voltage feedthroughs, structural supports, and barriers between high voltage insulating oil and the vacuum beam pipe in induction accelerator cells. Electric fields in the triple points should be minimized to prevent voltage breakdown. Mechanical stress can compromise seals and result in oil contamination of the insulator surface. We have tested various insulator cleaning procedures including ultrasonic cleaning with a variety of aqueous-based detergents, and manual scrubbing with various detergents. Water sheeting tests were used to determine the initial results of the cleaning methods. Ultimately, voltage breakdown tests will be used to quantify the benefits of these cleaning procedures

  14. 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.

  15. Heat insulating structure for use in transporting and handling gas of high temperature and pressure

    International Nuclear Information System (INIS)

    Mathusima, T.; Sato, T.; Uenishi, A.

    1980-01-01

    A heat insulating structure is described that has a heat-resistant tube disposed in a tubular cylindrical body and defining a passage for a high temperature gas, a heat insulating material disposed between the tube and the tubular cylindrical body and adapted to prevent the heat possessed by the gas from being transmitted to the tubular cylindrical body, and a spring adapted to bias the heat insulating material toward the inner surface of the tubular cylindrical body, so as to prevent the formation of a bypass passage for the gas including the gap between the tubular cylindrical body and the heat insulating material. The heat insulating material consists of a plurality of fibrous heat insulating materials mainly consisting of bulky fibrous materials and a plurality of shaped fibrous heat insulating materials. These fibrous heat insulating materials and the shaped fibrous heat insulating materials are arranged alternatingly and independently in the axial direction. In each of the bulky fibrous heat insulating material, disposed is a spring for biasing the shaped fibrous heat insulating material in the axial direction

  16. Insulating Foams Save Money, Increase Safety

    Science.gov (United States)

    2009-01-01

    Scientists at Langley Research Center created polyimide foam insulation for reusable cryogenic propellant tanks on the space shuttle. Meanwhile, a small Hialeah, Florida-based business, PolyuMAC Inc., was looking for advanced foams to use in the customized manufacturing of acoustical and thermal insulation. The company contacted NASA, licensed the material, and then the original inventors worked with the company's engineers to make a new material that was better for both parties. The new version, a high performance, flame retardant, flexible polyimide foam, is used for insulating NASA cryogenic propellant tanks and shows promise for use on watercraft, aircraft, spacecraft, electronics and electrical products, automobiles and automotive products, recreation equipment, and building and construction materials.

  17. Supporting Documentation for the 2008 Update to the Insulation Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Stovall, Therese K [ORNL

    2008-02-01

    The Insulation Fact Sheet provides consumers for general guidance and recommended insulation levels for their home. This fact sheet has been on-line since 1995 and this update addresses new insulation materials, as well as updated costs for energy and materials.

  18. Heat insulation support device

    International Nuclear Information System (INIS)

    Takahashi, Hiroyuki; Koda, Tomokazu; Motojima, Osamu; Yamamoto, Junya.

    1994-01-01

    The device of the present invention comprises a plurality of heat insulation legs disposed in a circumferential direction. Each of the heat insulative support legs has a hollow shape, and comprises an outer column and an inner column as support structures having a heat insulative property (heat insulative structure), and a thermal anchor which absorbs compulsory displacement by a thin flat plate (displacement absorber). The outer column, the thermal anchor and the inner column are connected by a support so as to offset the positional change of objects to be supported due to shrinkage when they are shrunk. In addition, the portion between the superconductive coils as the objects to be supported and the inner column is connected by the support. The superconductive thermonuclear device is entirely contained in a heat insulative vacuum vessel, and the heat insulative support legs are disposed on a lower lid of the heat insulative vacuum vessel. With such a constitution, they are strengthened against lateral load and buckling, thereby enabling to reduce the amount of heat intrusion while keeping the compulsory displacement easy to be absorbed. (I.N.)

  19. Interfacial Coatings for Inorganic Composite Insulation Systems

    International Nuclear Information System (INIS)

    Hooker, M. W.; Fabian, P. E.; Stewart, M. W.; Grandlienard, S. D.; Kano, K. S.

    2006-01-01

    Inorganic (ceramic) insulation materials are known to have good radiation resistance and desirable electrical and mechanical properties at cryogenic and elevated temperatures. In addition, ceramic materials can withstand the high-temperature reaction cycle used with Nb3Sn superconductor materials, allowing the insulation to be co-processed with the superconductor in a wind-and-react fabrication process. A critical aspect in the manufacture of ceramic-based insulation systems is the deposition of suitable fiber-coating materials that prevent chemical reaction of the fiber and matrix materials, and thus provide a compliant interface between the fiber and matrix, which minimizes the impact of brittle failure of the ceramic matrix. Ceramic insulation produced with CTD-FI-202 fiber interfaces have been found to exhibit very high shear and compressive strengths. However, this material is costly to produce. Thus, the goal of the present work is to evaluate alternative, lower-cost materials and processes. A variety of oxide and polyimide coatings were evaluated, and one commercially available polyimide coating has been shown to provide some improvement as compared to uncoated and de-sized S2 glass

  20. Inverse participation ratio and localization in topological insulator phase transitions

    International Nuclear Information System (INIS)

    Calixto, M; Romera, E

    2015-01-01

    Fluctuations of Hamiltonian eigenfunctions, measured by the inverse participation ratio (IPR), turn out to characterize topological-band insulator transitions occurring in 2D Dirac materials like silicene, which is isostructural with graphene but with a strong spin–orbit interaction. Using monotonic properties of the IPR, as a function of a perpendicular electric field (which provides a tunable band gap), we define topological-like quantum numbers that take different values in the topological-insulator and band-insulator phases. (paper)

  1. 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)

  2. Vacuum foil insulation system

    International Nuclear Information System (INIS)

    Hanson, J.P.; Sabolcik, R.E.; Svedberg, R.C.

    1976-01-01

    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. The insulation is for an implantable nuclear powered artificial heart

  3. Estimation of changes in insulation resistance with various design parameters of interdigitated wire loops.

    Energy Technology Data Exchange (ETDEWEB)

    Cordaro, Joseph Gabriel [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Jones, Reese E. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Neel, Wiley Christopher [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2015-09-01

    In this report we explore the sensitivities of the insulation resistance between two loops of wire embedded in insulating materials with a simple, approximate model. We discuss limita- tions of the model and ideas for improvements.

  4. Radiant Heat Transfer in Reusable Surface Insulation

    Science.gov (United States)

    Hughes, T. A.; Linford, R. M. F.; Chmitt, R. J.; Christensen, H. E.

    1973-01-01

    During radiant testing of mullite panels, temperatures in the insulation and support structure exceeded those predicted on the basis of guarded hot plate thermal conductivity tests. Similar results were obtained during arc tunnel tests of mullite specimens. The differences between effective conductivity and guarded hot plate values suggested that radiant transfer through the mullite was occurring. To study the radiant transport, measurements were made of the infrared transmission through various insulating materials and fibers of interest to the shuttle program, using black body sources over the range of 780 to 2000 K. Experimental data were analyzed and scattering coefficients were derived for a variety of materials, fiber diameters, and source temperature.

  5. Thermal insulation layer for the vacuum containers of a thermonuclear device

    International Nuclear Information System (INIS)

    Nishikawa, Masana; Yamada, Masao; Kameari, Akihisa; Niikura, Setsuo.

    1980-01-01

    Purpose: To prevent temperature rise of a thermal insulation layer for a vacuum container of a thermonuclear device higher than allowable value when irradiated by neutron by constructing the layer of a cooling unit in thermal insulation material. Constitution: A metal plate attached with cooling pipes is buried in a thermal insulation material forming a thermal insulation layer to form the layer provided between a vacuum container of a thermonuclear device and a shield. (Yoshihara, H.)

  6. Cooper Pairs in Insulators?

    International Nuclear Information System (INIS)

    Valles, James

    2008-01-01

    Nearly 50 years elapsed between the discovery of superconductivity and the emergence of the microscopic theory describing this zero resistance state. The explanation required a novel phase of matter in which conduction electrons joined in weakly bound pairs and condensed with other pairs into a single quantum state. Surprisingly, this Cooper pair formation has also been invoked to account for recently uncovered high-resistance or insulating phases of matter. To address this possibility, we have used nanotechnology to create an insulating system that we can probe directly for Cooper pairs. I will present the evidence that Cooper pairs exist and dominate the electrical transport in these insulators and I will discuss how these findings provide new insight into superconductor to insulator quantum phase transitions.

  7. Gas insulated substations

    CERN Document Server

    2014-01-01

    This book provides an overview on the particular development steps of gas insulated high-voltage switchgear, and is based on the information given with the editor's tutorial. The theory is kept low only as much as it is needed to understand gas insulated technology, with the main focus of the book being on delivering practical application knowledge. It discusses some introductory and advanced aspects in the meaning of applications. The start of the book presents the theory of Gas Insulated Technology, and outlines reliability, design, safety, grounding and bonding, and factors for choosing GIS. The third chapter presents the technology, covering the following in detail: manufacturing, specification, instrument transformers, Gas Insulated Bus, and the assembly process. Next, the book goes into control and monitoring, which covers local control cabinet, bay controller, control schemes, and digital communication. Testing is explained in the middle of the book before installation and energization. Importantly, ...

  8. Wrapped Multilayer Insulation

    Science.gov (United States)

    Dye, Scott A.

    2015-01-01

    New NASA vehicles, such as Earth Departure Stage (EDS), Orion, landers, and orbiting fuel depots, need improved cryogenic propellant transfer and storage for long-duration missions. Current cryogen feed line multilayer insulation (MLI) performance is 10 times worse per area than tank MLI insulation. During each launch, cryogenic piping loses approximately 150,000 gallons (equivalent to $300,000) in boil-off during transfer, chill down, and ground hold. Quest Product Development Corp., teaming with Ball Aerospace, developed an innovative advanced insulation system, Wrapped MLI (wMLI), to provide improved thermal insulation for cryogenic feed lines. wMLI is high-performance multilayer insulation designed for cryogenic piping. It uses Quest's innovative discrete-spacer technology to control layer spacing/ density and reduce heat leak. The Phase I project successfully designed, built, and tested a wMLI prototype with a measured heat leak 3.6X lower than spiral-wrapped conventional MLI widely used for piping insulation. A wMLI prototype had a heat leak of 7.3 W/m2, or 27 percent of the heat leak of conventional MLI (26.7 W/m2). The Phase II project is further developing wMLI technology with custom, molded polymer spacers and advancing the product toward commercialization via a rigorous testing program, including developing advanced vacuuminsulated pipe for ground support equipment.

  9. 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.

  10. 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)

    1997-12-31

    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.

  11. 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.

  12. Energy conservation through thermally insulated structures

    International Nuclear Information System (INIS)

    Abu-Dayyeh, Ayoub

    2006-01-01

    The propose of this paper is to explicate its title through investigating the different available thermal insulating materials and the various techniques of application, as practiced in Jordan, in particular, and as practiced in many parts of the world in general, which will satisfy Jordanian standards in terms of heat transmittance and thermal comfort. A brief comparison with international standards will shed some light on the stringent measures enforced in the developed world and on our striving aspirations to keep pace. The paper consists of four main parts, pseudoally divided. The first part will deal with the mechanism of heat loss and heat gain in structures during summer and winter. It will also explain the Time-lag phenomenon which is vital for providing thermal comfort inside the dwellings. The second part will evaluate the damages induced by the temperature gradients on the different elements of the structure, particularly next to exterior opening. The paper will also demonstrate the damages induced by water condensation and fungus growth on the internal surfaces of the structure and within its skeleton. A correlation between condensation and thermal insulation will be established. The third part of the paper will evaluate the different available thermal insulating materials and the application techniques which will satisfy the needs for thermal insulating and thermal comfort at the least cost possible. The criteria of an economical design shall be established. As a conclusion, the paper infers answers to the following different criteria discussed throughout the different parts of the paper. The main theme of questions can be summarized as follows: 1)How energy conservation is possible due to thermal insulation? 2)The feasibility of investing in thermal insulation? 3)Is thermal comfort and a healthy atmosphere possible inside the dwellings during all season! What are the conditions necessary to sustain them? 4)What environmental impacts can exist due to

  13. Sheath insulator final test report, TFE Verification Program

    International Nuclear Information System (INIS)

    1994-07-01

    The sheath insulator in a thermionic cell has two functions. First, the sheath insulator must electrically isolate the collector form the outer containment sheath tube that is in contact with the reactor liquid metal coolant. Second, The sheath insulator must provide for high uniform thermal conductance between the collector and the reactor coolant to remove away waste heat. The goals of the sheath insulator test program were to demonstrate that suitable ceramic materials and fabrication processes were available, and to validate the performance of the sheath insulator for TFE-VP requirements. This report discusses the objectives of the test program, fabrication development, ex-reactor test program, in-reactor test program, and the insulator seal specifications

  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 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...

  15. Sheath insulator final test report, TFE Verification Program

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The sheath insulator in a thermionic cell has two functions. First, the sheath insulator must electrically isolate the collector form the outer containment sheath tube that is in contact with the reactor liquid metal coolant. Second, The sheath insulator must provide for high uniform thermal conductance between the collector and the reactor coolant to remove away waste heat. The goals of the sheath insulator test program were to demonstrate that suitable ceramic materials and fabrication processes were available, and to validate the performance of the sheath insulator for TFE-VP requirements. This report discusses the objectives of the test program, fabrication development, ex-reactor test program, in-reactor test program, and the insulator seal specifications.

  16. Optimization of insulation of a linear Fresnel collector

    Science.gov (United States)

    Ardekani, Mohammad Moghimi; Craig, Ken J.; Meyer, Josua P.

    2017-06-01

    This study presents a simulation based optimization study of insulation around the cavity receiver of a Linear Fresnel Collector. This optimization study focuses on minimizing heat losses from a cavity receiver (maximizing plant thermal efficiency), while minimizing insulation cross-sectional area (minimizing material cost and cavity dead load), which leads to a cheaper and thermally more efficient LFC cavity receiver.

  17. Bonded stacked-ring insulator for the Antares electron gun

    International Nuclear Information System (INIS)

    Stine, R.D.; Allen, G.R.; Eaton, E.; Weinstein, B.

    1982-01-01

    A large diameter insulator utilizing epoxy bonding which has sufficient mechanical strength to support the 3000 kg cathode/grid assembly was developed. Bonding the insulator simplifies the handling and reduces the number of 0-ring seals to a minimum. We have described the material selection, bonding techniques and electrical design approach

  18. Organic insulator studies at Los Alamos

    International Nuclear Information System (INIS)

    Parkin, D.M.; Clinard, F.W.

    1981-01-01

    The effects of radiation on the structural and electrical properties of organic insulators to be used in superconducting magnets in fusion devices has been identified as a critical materials problem. These materials will be exposed to both γ-ray and neutron radiation. LANL has been asked by the OFE Materials Branch to look at the relationship between the effects of γ-ray and neutron radiation effects. Some thoughts on planning the program are outlined

  19. Using microtherm microporous insulation in smelter applications

    Science.gov (United States)

    MacKenzie, Iain

    2000-02-01

    Microtherm is effective in reducing shell temperatures in confined spaces where compression is severe and much insulation is required. This material can prove beneficial for applications such as cement and lime rotary kiln transition and hot zones; copper converters and anode furnaces; steel and iron ladles, tundishes, RH vessels, and blast furnaces; and aluminum filter boxes, runners, and metal transporters.

  20. Insulating jacket for heat sensitive components

    International Nuclear Information System (INIS)

    Class, G.

    1980-01-01

    The insulating jacket for long core components of sodium-cooled reactors consists of several layers of austenitic steel, between which a woven wire mesh of the same material is fitted. It is wound in the form of a spiral bandage on the core component. (DG) [de

  1. 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.

  2. Topological Insulator Nanowires and Nanoribbons

    KAUST Repository

    Kong, Desheng

    2010-01-13

    Recent theoretical calculations and photoemission spectroscopy measurements on the bulk Bi2Se3 material show that it is a three-dimensional topological insulator possessing conductive surface states with nondegenerate spins, attractive for dissipationless electronics and spintronics applications. Nanoscale topological insulator materials have a large surface-to-volume ratio that can manifest the conductive surface states and are promising candidates for devices. Here we report the synthesis and characterization of high quality single crystalline Bi2Se5 nanomaterials with a variety of morphologies. The synthesis of Bi 2Se5 nanowires and nanoribbons employs Au-catalyzed vapor-liquid-solid (VLS) mechanism. Nanowires, which exhibit rough surfaces, are formed by stacking nanoplatelets along the axial direction of the wires. Nanoribbons are grown along [1120] direction with a rectangular cross-section and have diverse morphologies, including quasi-one-dimensional, sheetlike, zigzag and sawtooth shapes. Scanning tunneling microscopy (STM) studies on nanoribbons show atomically smooth surfaces with ∼ 1 nm step edges, indicating single Se-Bi-Se-Bi-Se quintuple layers. STM measurements reveal a honeycomb atomic lattice, suggesting that the STM tip couples not only to the top Se atomic layer, but also to the Bi atomic layer underneath, which opens up the possibility to investigate the contribution of different atomic orbitais to the topological surface states. Transport measurements of a single nanoribbon device (four terminal resistance and Hall resistance) show great promise for nanoribbons as candidates to study topological surface states. © 2010 American Chemical Society.

  3. Voltage-driven magnetization control in topological insulator/magnetic insulator heterostructures

    Directory of Open Access Journals (Sweden)

    Michael E. Flatté

    2017-05-01

    Full Text Available A major barrier to the development of spin-based electronics is the transition from current-driven spin torque, or magnetic-field-driven magnetization reversal, to a more scalable voltage-driven magnetization reversal. To achieve this, multiferroic materials appear attractive, however the effects in current materials occur at very large voltages or at low temperatures. Here the potential of a new class of hybrid multiferroic materials is described, consisting of a topological insulator adjacent to a magnetic insulator, for which an applied electric field reorients the magnetization. As these materials lack conducting states at the chemical potential in their bulk, no dissipative charge currents flow in the bulk. Surface states at the interface, if present, produce effects similar to surface recombination currents in bipolar devices, but can be passivated using magnetic doping. Even without conducting states at the chemical potential, for a topological insulator there is a finite spin Hall conductivity provided by filled bands below the chemical potential. Spin accumulation at the interface with the magnetic insulator provides a torque on the magnetization. Properly timed voltage pulses can thus reorient the magnetic moment with only the flow of charge current required in the leads to establish the voltage. If the topological insulator is sufficiently thick the resulting low capacitance requires little charge current.

  4. Correlation among ESDD, NSDD and leakage current in distribution insulators

    International Nuclear Information System (INIS)

    Montoya, G.; Ramirez, I.; Montoya, J.I.

    2004-01-01

    The maintenance of distribution networks is more effective if the insulation contamination levels are known. The selection of measuring methods of pollution levels is then crucial. The relationship between several evaluation methods of pollution levels and the operating behaviour of several insulator profiles in a polluted zone is described. Laboratory tests were carried out to reproduce pollution levels found in the field. The quantity of non-soluble materials deposited over the insulators' surface affect the magnitude of the leakage current generated over a contaminated insulator. The relationship that defines leakage current with respect to the equivalent salt deposit density (ESDD) level for a specific non-soluble material level is almost linear, from which it is possible to develop a relationship between them for each insulator. (author)

  5. Study of Hygrothermal Processes in External Walls with Internal Insulation

    Directory of Open Access Journals (Sweden)

    Biseniece Edite

    2018-03-01

    Full Text Available Being an important contributor to the final energy consumption, historic buildings built before 1945 have high specific heating energy consumption compared to current energy standards and norms. However, they often cannot be insulated from the outside due to their heritage and culture value. Internal insulation is an alternative. However internal insulation faces challenges related to hygrothermal behaviour leading to mold growth, freezing, deterioration and other risks. The goal of this research is to link hygrothermal simulation results with experimental results for internally insulated historic brick masonry to assess correlation between simulated and measured data as well as the most influential parameters. The study is carried out by both a mathematical simulation tool and laboratory tests of historic masonry with internal insulation with four insulation materials (mineral wool, EPS, wood fiber and granulated aerogel in a cold climate (average 4000 heating degree days. We found disparity between measured and simulated hygrothermal performance of studied constructions due to differences in material parameters and initial conditions of materials. The latter plays a more important role than material parameters. Under a steady state of conditions, the condensate tolerating system varies between 72.7 % and 80.5 % relative humidity, but in condensate limiting systems relative humidity variates between 73.3 % and 82.3 %. The temperature between the masonry wall and all insulation materials has stabilized on average at +10 °C. Mold corresponding to Mold index 3 was discovered on wood fiber mat.

  6. Study of Hygrothermal Processes in External Walls with Internal Insulation

    Science.gov (United States)

    Biseniece, Edite; Freimanis, Ritvars; Purvins, Reinis; Gravelsins, Armands; Pumpurs, Aivars; Blumberga, Andra

    2018-03-01

    Being an important contributor to the final energy consumption, historic buildings built before 1945 have high specific heating energy consumption compared to current energy standards and norms. However, they often cannot be insulated from the outside due to their heritage and culture value. Internal insulation is an alternative. However internal insulation faces challenges related to hygrothermal behaviour leading to mold growth, freezing, deterioration and other risks. The goal of this research is to link hygrothermal simulation results with experimental results for internally insulated historic brick masonry to assess correlation between simulated and measured data as well as the most influential parameters. The study is carried out by both a mathematical simulation tool and laboratory tests of historic masonry with internal insulation with four insulation materials (mineral wool, EPS, wood fiber and granulated aerogel) in a cold climate (average 4000 heating degree days). We found disparity between measured and simulated hygrothermal performance of studied constructions due to differences in material parameters and initial conditions of materials. The latter plays a more important role than material parameters. Under a steady state of conditions, the condensate tolerating system varies between 72.7 % and 80.5 % relative humidity, but in condensate limiting systems relative humidity variates between 73.3 % and 82.3 %. The temperature between the masonry wall and all insulation materials has stabilized on average at +10 °C. Mold corresponding to Mold index 3 was discovered on wood fiber mat.

  7. Sustainable wall construction and exterior insulation retrofit technology process and structure

    Science.gov (United States)

    Vohra, Arun

    2000-01-01

    A low-cost process for exterior wall insulation retrofit, or new wall construction by stacking layers of fabric tube filled with insulating material against a wall and covering them with mesh and stucco provides a durable structure with good insulating value.

  8. 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.

  9. Artificial heart system thermal insulation component development

    International Nuclear Information System (INIS)

    Svedberg, R.C.; Buckman, R.W. Jr.

    1975-01-01

    A concentric cup vacuum multifoil insulation system has been selected by virtue of its size, weight, and thermal performance to insulate the hot radioisotope portion of the thermal converter of an artificial implantable heart system. A factor of 2 improvement in thermal performance, based on the heat loss per number of foil layers (minimum system weight and volume) has been realized over conventional spiral wrapped multifoil vacuum insulation. This improvement is the result of the concentric cup construction to maintain a uniform interfoil spacing and the elimination of corner heat losses. Based on external insulation system dimensions (surface area in contact with host body), heat losses of 0.019 W/ cm 2 at 1140 0 K (1600 0 F) and 0.006 W/cm 2 at 920 0 K (1200 0 F) have been achieved. Factors which influence thermal performance of the nickel foil concentric cup insulation system include the number of cups, configuration and method of application of zirconia (ZrO 2 ) spacer material, system pressure, emittance of the cups, and operating temperature

  10. Energy production from waste with regard to the possibilities of high-grade insulating granulates for building material through the distension method

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, P

    1981-01-01

    A study is made of the extent to which energy contained in residual materials can be released and be used for making concretes, based on waste products from industry, domestic and communal refuse as well as filings from the coal mining industry, flotation and screening plants, and coal-pit power plants. Also examined is the organic composition of the residue for residual energy release. The studies indicate that significant energy savings can be obtained by the release of residual energy of original raw material in the making of concretes. 14 figures, 6 tables.

  11. Electrical machining method of insulating ceramics

    International Nuclear Information System (INIS)

    Fukuzawa, Y.; Mohri, N.; Tani, T.

    1999-01-01

    This paper describes a new electrical discharge machining method for insulating ceramics using an assisting electrode with either a sinking electrical discharge machine or a wire electrical discharge machine. In this method, the metal sheet or mesh is attached to the ceramic surface as an assisting material for the discharge generation around the insulator surface. When the machining condition changes from the attached material to the workpiece, a cracked carbon layer is formed on the workpiece surface. As this layer has an electrical conductivity, electrical discharge occurs in working oil between the tool electrode and the surface of the workpiece. The carbon is formed from the working oil during this electrical discharge. Even after the material is machined, an electrical discharge occurs in the gap region between the tool electrode and the ceramic because an electrically conductive layer is generated continuously. Insulating ceramics can be machined by the electrical discharge machining method using the above mentioned surface modification phenomenon. In this paper the authors show a machined example demonstrating that the proposed method is available for machining a complex shape on insulating ceramics. Copyright (1999) AD-TECH - International Foundation for the Advancement of Technology Ltd

  12. Electrical resistivity study of insulators

    International Nuclear Information System (INIS)

    Liesegang, J.; Senn, B.C.; Holcombe, S.R.; Pigram, P.J.

    1998-01-01

    Full text: Conventional methods of electrical resistivity measurement of dielectric materials involve the application of electrodes to a sample whereby a potential is applied and a current through the material is measured. Although great care and ingenuity has often been applied to this technique, the recorded values of electrical resistivity (p), especially for insulator materials, show great disparity. In earlier work by the authors, a method for determining surface charge decay [Q(t)], using a coaxial cylindrical capacitor arrangement interfaced to a personal computer, was adapted to allow the relatively straightforward measurement of electrical resistivity in the surface region of charged insulator materials. This method was used to develop an ionic charge transport theory, based on Mott-Gurney diffusion to allow a greater understanding into charge transport behaviour. This theory was extended using numerical analysis to produce a two dimensional (2-D) computational model to allow the direct comparison between experimental and theoretical charge decay data. The work also provided a means for the accurate determination of the diffusion coefficient (D) and the layer of thickness of surface charge (Δz) on the sample. The work outlined here involves an extension of the theoretical approach previously taken, using a computational model based more closely on the 3-D experimental set-up, to reinforce the level of confidence in the results achieved for the simpler 2-D treatment. Initially, a 3-D rectangular box arrangement similar to the experimental set-up was modelled and a theoretical and experimental comparison of voltage decay results made. This model was then transferred into cylindrical coordinates to allow it to be almost identical to the experiment and again a comparison made. In addition, theoretical analysis of the coupled non-linear partial differential equations governing the charge dissipation process has led to a simplification involving directly, the

  13. CATALOG OF MATERIALS AS POTENTIAL SOURCES OF INDOOR AIR EMISSIONS - VOLUME 1. INSULATION, WALLCOVERINGS, RESI- LIENT FLOOR COVERINGS, CARPET, ADHESIVES, SEALANTS AND CAULKS, AND PESTICIDES

    Science.gov (United States)

    The report discusses and presents data on constituents and emissions from products that have the potential to impact the indoor air environment. t is a tool to be used by researchers to help organize the study of materials as potential sources of indoor air emissions. ncluded are...

  14. Radioconductivity of insulators: their potential for ionographic imaging

    International Nuclear Information System (INIS)

    DeWerd, L.A.; Moran, P.R.

    1975-01-01

    Measurements of the radioconductivity and thermocurrent properties of relatively pure insulating solids indicate charge collection yields which compare favorably to materials presently used for ionography. The radioconductivity varies with temperature giving rise to temperature windows of feasible use

  15. Measure Guideline: Sealing and Insulating of Ducts in Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R.; Puttagunta, S.

    2011-12-01

    This document begins with a discussion on potential cost and performance benefits of duct sealing and insulating. It continues with a review of typical duct materials and components and the overall procedures for assessing and improving the duct system.

  16. Measure Guideline. Sealing and Insulating Ducts in Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Puttagunta, S. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2011-12-01

    This document begins with a discussion on potential cost and performance benefits of duct sealing and insulating. It continues with a review of typical duct materials and components and the overall procedures for assessing and improving the duct system.

  17. Wire Insulation Incorporating Self-Healing Polymers (WIISP), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NextGen and Virginia Tech are developing a self-healing material for wire insulation using a class of ionomeric polymers. These ionomers exhibit self-healing...

  18. Polymer-Reinforced, Non-Brittle, Lightweight Cryogenic Insulation

    Science.gov (United States)

    Hess, David M.

    2013-01-01

    The primary application for cryogenic insulating foams will be fuel tank applications for fueling systems. It is crucial for this insulation to be incorporated into systems that survive vacuum and terrestrial environments. It is hypothesized that by forming an open-cell silica-reinforced polymer structure, the foam structures will exhibit the necessary strength to maintain shape. This will, in turn, maintain the insulating capabilities of the foam insulation. Besides mechanical stability in the form of crush resistance, it is important for these insulating materials to exhibit water penetration resistance. Hydrocarbon-terminated foam surfaces were implemented to impart hydrophobic functionality that apparently limits moisture penetration through the foam. During the freezing process, water accumulates on the surfaces of the foams. However, when hydrocarbon-terminated surfaces are present, water apparently beads and forms crystals, leading to less apparent accumulation. The object of this work is to develop inexpensive structural cryogenic insulation foam that has increased impact resistance for launch and ground-based cryogenic systems. Two parallel approaches will be pursued: a silica-polymer co-foaming technique and a post foam coating technique. Insulation characteristics, flexibility, and water uptake can be fine-tuned through the manipulation of the polyurethane foam scaffold. Silicate coatings for polyurethane foams and aerogel-impregnated polyurethane foams have been developed and tested. A highly porous aerogel-like material may be fabricated using a co-foam and coated foam techniques, and can insulate at liquid temperatures using the composite foam

  19. Beyond insulation and isolation

    DEFF Research Database (Denmark)

    Højlund, Marie Koldkjær

    2016-01-01

    are insulation and isolation strategies to reduce measurable and perceptual noise levels. However, these strategies do not actively support the need to feel like an integral part of the shared hospital environment, which is a key element in creating healing environments, according to the paradigm of Evidence-Based...

  20. Lateral topological crystalline insulator heterostructure

    Science.gov (United States)

    Sun, Qilong; Dai, Ying; Niu, Chengwang; Ma, Yandong; Wei, Wei; Yu, Lin; Huang, Baibiao

    2017-06-01

    The emergence of lateral heterostructures fabricated by two-dimensional building blocks brings many exciting realms in material science and device physics. Enriching available nanomaterials for creating such heterostructures and enabling the underlying new physics is highly coveted for the integration of next-generation devices. Here, we report a breakthrough in lateral heterostructure based on the monolayer square transition-metal dichalcogenides MX2 (M  =  W, X  =  S/Se) modules. Our results reveal that the MX2 lateral heterostructure (1S-MX2 LHS) can possess excellent thermal and dynamical stability. Remarkably, the highly desired two-dimensional topological crystalline insulator phase is confirmed by the calculated mirror Chern number {{n}\\text{M}}=-1 . A nontrivial band gap of 65 meV is obtained with SOC, indicating the potential for room-temperature observation and applications. The topologically protected edge states emerge at the edges of two different nanoribbons between the bulk band gap, which is consistent with the mirror Chern number. In addition, a strain-induced topological phase transition in 1S-MX2 LHS is also revealed, endowing the potential utilities in electronics and spintronics. Our predictions not only introduce new member and vitality into the studies of lateral heterostructures, but also highlight the promise of lateral heterostructure as appealing topological crystalline insulator platforms with excellent stability for future devices.

  1. 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.

  2. Tetradymites as thermoelectrics and topological insulators

    Science.gov (United States)

    Heremans, Joseph P.; Cava, Robert J.; Samarth, Nitin

    2017-10-01

    Tetradymites are M2X3 compounds — in which M is a group V metal, usually Bi or Sb, and X is a group VI anion, Te, Se or S — that crystallize in a rhombohedral structure. Bi2Se3, Bi2Te3 and Sb2Te3 are archetypical tetradymites. Other mixtures of M and X elements produce common variants, such as Bi2Te2Se. Because tetradymites are based on heavy p-block elements, strong spin-orbit coupling greatly influences their electronic properties, both on the surface and in the bulk. Their surface electronic states are a cornerstone of frontier work on topological insulators. The bulk energy bands are characterized by small energy gaps, high group velocities, small effective masses and band inversion near the centre of the Brillouin zone. These properties are favourable for high-efficiency thermoelectric materials but make it difficult to obtain an electrically insulating bulk, which is a requirement of topological insulators. This Review outlines recent progress made in bulk and thin-film tetradymite materials for the optimization of their properties both as thermoelectrics and as topological insulators.

  3. 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.

  4. Experimental and numerical study of heat transfer across insulation wall of a refrigerated integral panel van

    International Nuclear Information System (INIS)

    Glouannec, Patrick; Michel, Benoit; Delamarre, Guillaume; Grohens, Yves

    2014-01-01

    This paper presents an experimental and numerical design study of an insulation wall for refrigerated vans. The thermophysical properties of the insulating multilayer panel, the external environment impact (solar irradiation, temperature, etc.) and durability are taken into account. Different tools are used to characterize the thermal performances of the insulation walls and the thermal properties of the insulation materials are measured. In addition, an experiment at the wall scale is carried out and a 2D FEM model of heat and mass transfer within the wall is formulated. Three configurations are studied with this design approach. Multilayer insulation walls containing reflective multi-foil insulation, aerogel and phase change materials (PCM) are tested. Promising results are obtained with these materials, especially the reduction of peak heat transfer and energy consumption during the daytime period. Furthermore, the major influence of solar irradiation is highlighted as it can increase the peak heat transfer crossing the insulation wall by up to 43%. Nevertheless, we showed that the use of reflective multi-foil insulation and aerogel layers allowed decreasing this impact by 27%. - Highlights: • A design study of an insulation wall for a refrigerated van is carried out. • Experimental and numerical studies of multilayer insulation walls are performed. • The major influence of solar irradiation is highlighted. • New insulation materials (reflective multi-foil, aerogel and PCM) are tested

  5. Metal-insulator transitions

    Science.gov (United States)

    Imada, Masatoshi; Fujimori, Atsushi; Tokura, Yoshinori

    1998-10-01

    Metal-insulator transitions are accompanied by huge resistivity changes, even over tens of orders of magnitude, and are widely observed in condensed-matter systems. This article presents the observations and current understanding of the metal-insulator transition with a pedagogical introduction to the subject. Especially important are the transitions driven by correlation effects associated with the electron-electron interaction. The insulating phase caused by the correlation effects is categorized as the Mott Insulator. Near the transition point the metallic state shows fluctuations and orderings in the spin, charge, and orbital degrees of freedom. The properties of these metals are frequently quite different from those of ordinary metals, as measured by transport, optical, and magnetic probes. The review first describes theoretical approaches to the unusual metallic states and to the metal-insulator transition. The Fermi-liquid theory treats the correlations that can be adiabatically connected with the noninteracting picture. Strong-coupling models that do not require Fermi-liquid behavior have also been developed. Much work has also been done on the scaling theory of the transition. A central issue for this review is the evaluation of these approaches in simple theoretical systems such as the Hubbard model and t-J models. Another key issue is strong competition among various orderings as in the interplay of spin and orbital fluctuations. Experimentally, the unusual properties of the metallic state near the insulating transition have been most extensively studied in d-electron systems. In particular, there is revived interest in transition-metal oxides, motivated by the epoch-making findings of high-temperature superconductivity in cuprates and colossal magnetoresistance in manganites. The article reviews the rich phenomena of anomalous metallicity, taking as examples Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Ru compounds. The diverse phenomena include strong spin and

  6. Development of large insulator rings for the TOKAMAK Fusion Test Reactor

    International Nuclear Information System (INIS)

    Brown, T.; Tobin, A.

    1977-01-01

    Research and development leading to the manufacture of large ceramic insulator rings for the TFTR (TOKAMAK Fusion Test Reactor). Material applictions, fabrication approach and testing activities are highlighted

  7. Insulating and sheathing materials of electric and optical cables: common test methods part 4-1: methods specific to polyethylene and polypropylene compounds – resistance to environmental stress cracking – measurement of the melt flow index – carbon black and/or mineral filler content measurement in polyethylene by direct combustion – measurement of carbon black content by thermogravimetric analysis (TGA) – assessment of carbon black dispersion in polyethylene using a microscope

    CERN Document Server

    International Electrotechnical Commission. Geneva

    2004-01-01

    Specifies the test methods to be used for testing polymeric insulating and sheathing materials of electric cables for power distribution and telecommunications including cables used on ships. Gives the methods for measurements of the resistance to environmental stress cracking, for wrapping test after thermal ageing in air, for measurement of melt flow index and for measurement of carbon black and/or mineral filler content, which apply to PE and PP coumpounds, including cellular compounds and foam skin for insulation.

  8. Super-insulation

    International Nuclear Information System (INIS)

    Gerold, J.

    1985-01-01

    The invention concerns super-insulation, which also acts as spacing between two pressurized surfaces, where the crossing bars in at least two layers are provided, with interposed foil. The super-insulation is designed so that it can take compression forces and limits thermal radiation and thermal conduction sufficiently, where the total density of heat flow is usually limited to a few watts per m 2 . The solution to the problem is characterized by the fact that the bars per layer are parallel and from layer to layer they are at an angle to each other and the crossover positions of the bars of different layers are at fixed places and so form contact columns. The basic idea is that bars crossing over each other to support compression forces are used so that contact columns are formed, which are compressed to a certain extent by the load. (orig./PW) [de

  9. Compact vacuum insulation embodiments

    Science.gov (United States)

    Benson, D.K.; Potter, T.F.

    1992-04-28

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

  10. Compact vacuum insulation

    Science.gov (United States)

    Benson, D.K.; Potter, T.F.

    1993-01-05

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  11. 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...

  12. Innovative Retrofit Insulation Strategies for Concrete Masonry Foundations

    Energy Technology Data Exchange (ETDEWEB)

    Huelman, P. [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership; Goldberg, L. [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership; Jacobson, R. [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership

    2015-05-06

    This study was designed to test a new approach for foundation insulation retrofits, with the goal of demonstrating improved moisture control, improved occupant comfort, and reduced heat loss. Because conducting experimental research on existing below-grade assemblies is very difficult, most of the results are based on simulations. The retrofit approach consists of filling open concrete block cores with an insulating material and adding R-10 exterior insulation that extends 1 ft below grade. The core fill is designed to improve the R-value of the foundation wall and increase the interior wall surface temperature, but more importantly to block convection currents that could otherwise increase moisture loads on the foundation wall and interior space. The exterior insulation significantly reduces heat loss through the most exposed part of the foundation and further increases the interior wall surface temperature. This improves occupant comfort and decreases the risk of condensation. Such an insulation package avoids the full-depth excavation necessary for exterior insulation retrofits, reduces costs, and eliminates the moisture and indoor air quality risks associated with interior insulation retrofits. Retrofit costs for the proposed approach were estimated at roughly half those of a full-depth exterior insulation retrofit.

  13. High-k materials in the electrolyte/insulator/silicon configuration. Characterization and application in bio-electronics; Hoch-k-Materialien in der Elektrolyt/Isolator/Silizium-Konfiguration. Charakterisierung und Anwendung in der Bioelektronik

    Energy Technology Data Exchange (ETDEWEB)

    Wallrapp, F

    2006-12-19

    In order to elicit action potentials in nerve cells adhered on electrodes, a certain current is required across the electrode. Electrochemical reactions may cause damage to cells and electrodes. This is evaded by using silicon electrodes which are insulated by a dielectric. In doing so, only capacitive current is flowing, and electrochemical are avoided. The aim of this work was to fabricate novel stimulation chips exhibiting an enhanced capacitance which render new biological applications possible. These chips were to be characterized and used for the stimulation of cells. The formerly used dielectric SiO{sub 2} was replaced by HfO{sub 2} and TiO{sub 2}, with both of them featuring a higher dielectric constant. They were deposited on the silicon substrate by ALD (atomic layer deposition). The chips were characterized in the electrolyte/insulator/semiconductor (EIS) configuration. Owing to the low leakage current of the EIS configuration, the characterization of the high-k materials was possible in more detail as compared to using a metallic top contact (MIS configuration). The voltage-dependent capacitances of the HfO{sub 2} films could be interpreted by means of a common metal/SiO{sub 2}/silicon system. In contrast, the TiO{sub 2} films exhibited interesting properties which could only be rationalized with the help of numerical calculations assuming free electrons in the TiO{sub 2}. The low-lying conduction band of TiO{sub 2} caused accumulation of electrons within the TiO{sub 2} for certain voltages, which led to an enhanced capacitance. The effects of high voltages, frequency, film thickness and interlayer composition were examined and brought into compliance with the model. The novel TiO{sub 2} stimulation devices featured a five-fold capacitance increase as compared to former SiO{sub 2} chips. Using them, two fundamental stimulation mechanisms were induced in HEK293 cells expressing the recombinant potassium channel Kv1.3: Opening of ion channels and

  14. 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

  15. Pourable Foam Insulation

    Science.gov (United States)

    Harvey, James A.; Butler, John M.; Chartoff, Richard P.

    1989-01-01

    Report describes search for polyisocyanurate/polyurethane foam insulation with superior characteristics. Discusses chemistry of current formulations. Tests of formulations, of individual ingredients and or alternative new formulations described. Search revealed commercially available formulations exhibiting increased thermal stability at temperatures up to 600 degree C, pours readily before curing, presents good appearance after curing, and remains securely bonded to aluminum at cryogenic temperatures. Total of 42 different formulations investigated, 10 found to meet requirements.

  16. 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.

  17. Insulated Wire Fed Floating Monopole Antenna for Coastal Monitoring

    Directory of Open Access Journals (Sweden)

    Z. M. Loni

    2018-04-01

    Full Text Available A thin, flexible, insulated wire submerged in seawater forms a coaxial cable which has attenuation at ultra-high frequency (UHF dependent on the operating frequency, the diameter of the insulating material and the diameter of the inner conductor. An extension of the insulated wire above the surface through a spherical float forms a monopole antenna. Attenuation through the wire depends on the conductivity and temperature of seawater. This paper reports the effect of electromagnetic (EM wave propagation at 433 MHz through insulated wires with different radii of the insulating material and inner conductor. The attenuation was calculated and measured in the range of 32-47 dB/m. The propagation from the monopole antenna to a fixed shore based receiver was measured to be approximately equal to 1 dB/m. The propagation measurements were compared with a shielded coaxial cable. Results show that the propagation range depends on the ratio of the insulation radius to conductor radius for insulated wire, however, a shielded coaxial cable showed no significant attenuation. The technique has applications in coastal wireless sensor networks where the water depth changes continually due to tide and wave motion.

  18. Method and Apparatus of Measuring Velocity and Sound Attenuation Coefficient in Bulk Materials Based on the Analysis of the Structure of Sound-Insulation Materials on the Basis of Perlite

    Science.gov (United States)

    Kapranov, B. I.; Mashanov, A. P.

    2017-04-01

    This paper presents the results of research and describes the apparatus for measuring the acoustic characteristics of bulk materials. Ultrasound, it has passed through a layer of bulk material, is further passes through an air gap. The presence of air gap prevents from measuring tract mechanical contacts, but complicates the measurement technology Studies were conducted on the example of measuring the acoustic characteristics of the widely used perlite-based sound-proofing material.

  19. Analytical model of heat transfer in porous insulation around cold pipes

    DEFF Research Database (Denmark)

    Guldbrandsen, Tom; Karlsson, Per W.; Korsgaard, Vagn

    2011-01-01

    cloth is wrapped around the cold tube and extended through a slit in the tubular insulation and a slot in the facing to the ambient so that condensed water can evaporate into the air. Some of the moisture in that part of the wicking cloth situated in the slit in the tubular insulation will diffuse......A thermal insulation system is analysed that consists of a cold tube insulated with a porous material faced with a vapour retarding foil.Water vapour will diffuse through the vapour retarding foil and condense on the cold tube. To avoid build-up of water in the insulation a hydrophilic wicking...

  20. Pilot cryo tunnel: Attachments, seals, and insulation

    Science.gov (United States)

    Wilson, J. F.; Ware, G. D.; Ramsey, J. W., Jr.

    1974-01-01

    Several different tests are described which simulated the actual configuration of a cryogenic wind tunnel operating at pressures up to 5 atmospheres (507 kPa) and temperatures from -320 F (78K) to 120 F (322K) in order to determine compatible bolting, adequate sealing, and effective insulating materials. The evaluation of flange attachments (continuous threaded studs) considered bolting based on compatible flanges, attachment materials, and prescribed bolt elongations. Various types of seals and seal configurations were studied to determine suitability and reusability under the imposed pressure and temperature loadings. The temperature profile was established for several materials used for structural supports.

  1. Creep of granulated loose-fill insulation

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    This report presents a proposal for a standardised method for creep tests and the necessary theoretical framework that can be used to describe creep of a granulated loose-fill material. Furthermore results from a round robin test are shown. The round robin test was carried out in collaboration...... with SP-Building Physics in Sweden and VTT Building Technology in Finland. For the round robin test a cellulosic fibre insulation material was used. The proposed standardised method for creep tests and theories are limited to cases when the granulated loose-fill material is exposed to a constant...

  2. Measure Guideline: Guidance on Taped Insulating Sheathing Drainage Planes

    Energy Technology Data Exchange (ETDEWEB)

    Grin, A. [Building Science Corporation, Somerville, MA (United States); Lstiburek, J. [Building Science Corporation, Somerville, MA (United States)

    2014-09-01

    The goal of this research is to provide durable and long-term water management solutions using exterior insulating sheathing as part of the water management system. It is possible to tape or seal the joints in insulating sheathing to create a drainage plane and even an air control layer. There exists the material durability component of the tape as well as the system durability component being the taped insulating sheathing as the drainage plane. This measure guideline provides best practice and product recommendations from the interviewed contractors and homebuilders who collectively have a vast amount of experience. Three significant issues were discussed with the group, which are required to make taped insulating sheathing a simple, long-term, and durable drainage plane: horizontal joints should be limited or eliminated wherever possible; where a horizontal joint exists use superior materials; and frequent installation inspection and regular trade training are required to maintain proper installation.

  3. Step tunneling enhanced asymmetry in metal-insulator-insulator-metal (MIIM) diodes for rectenna applications

    Science.gov (United States)

    Alimardani, N.; Conley, J. F.

    2013-09-01

    We combine nanolaminate bilayer insulator tunnel barriers (Al2O3/HfO2, HfO2/Al2O3, Al2O3/ZrO2) deposited via atomic layer deposition (ALD) with asymmetric work function metal electrodes to produce MIIM diodes with enhanced I-V asymmetry and non-linearity. We show that the improvements in MIIM devices are due to step tunneling rather than resonant tunneling. We also investigate conduction processes as a function of temperature in MIM devices with Nb2O5 and Ta2O5 high electron affinity insulators. For both Nb2O5 and Ta2O5 insulators, the dominant conduction process is established as Schottky emission at small biases and Frenkel-Poole emission at large biases. The energy depth of the traps that dominate Frenkel-Poole emission in each material are estimated.

  4. Excavationless Exterior Foundation Insulation Exploratory Study

    Energy Technology Data Exchange (ETDEWEB)

    Mosiman, G.; Wagner, R.; Schirber, T.

    2013-02-01

    The key objective of this exploratory study was to investigate the feasibility of the development or adoption of technologies that would enable a large percentage of existing homes in cold climates to apply a combination 'excavationless' soil removal process with appropriate insulation and water management on the exterior of existing foundations at a low cost. Our approach was to explore existing excavation and material technologies and systems to discover whether potential successful combinations existed.

  5. High performance thermal insulation systems (HiPTI). Vacuum insulated products (VIP). Proceedings of the international conference and workshop

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, M.; Bertschinger, H.

    2001-07-01

    These are the proceedings of the International Conference and Workshop held at EMPA Duebendorf, Switzerland, in January 2001. The papers presented at the conference's first day included contributions on the role of high-performance insulation in energy efficiency - providing an overview of available technologies and reviewing physical aspects of heat transfer and the development of thermal insulation as well as the state of the art of glazing technologies such as high-performance and vacuum glazing. Also, vacuum-insulated products (VIP) with fumed silica, applications of VIP systems in technical building systems, nanogels, VIP packaging materials and technologies, measurement of physical properties, VIP for advanced retrofit solutions for buildings and existing and future applications for advanced low energy building are discussed. Finally, research and development concerning VIP for buildings are reported on. The workshops held on the second day covered a preliminary study on high-performance thermal insulation materials with gastight porosity, flexible pipes with high performance thermal insulation, evaluation of modern insulation systems by simulation methods as well as the development of vacuum insulation panels with a stainless steel envelope.

  6. 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)

  7. Some characteristics of metal migration in or on the surface of insulators

    International Nuclear Information System (INIS)

    Shields, R.B.

    1978-03-01

    This report reviews the migration of metals, principally silver, in or on the surface of insulating materials, by electrolytic processes. These processes are described for various metals, insulating materials and physical conditions, with numerous examples from the literature. While it is concluded that the only sure way to prevent degradation of insulation due to metal migration is to avoid the use of migration-prone metals, some other measures are mentioned which have been reported to reduce the extent of the growth. (author)

  8. Parametric and non-parametric models for lifespan modeling of insulation systems in electrical machines

    OpenAIRE

    Salameh , Farah; Picot , Antoine; Chabert , Marie; Maussion , Pascal

    2017-01-01

    International audience; This paper describes an original statistical approach for the lifespan modeling of electric machine insulation materials. The presented models aim to study the effect of three main stress factors (voltage, frequency and temperature) and their interactions on the insulation lifespan. The proposed methodology is applied to two different insulation materials tested in partial discharge regime. Accelerated ageing tests are organized according to experimental optimization m...

  9. A water blown urethane insulation for use in cryogenic environments

    Science.gov (United States)

    Blevins, Elana; Sharpe, Jon

    1995-01-01

    Thermal Protection Systems (TPS) of NASA's Space Shuttle External Tank include polyurethane and polyisocyanurate modified polyurethane foam insulations. These insulations, currently foamed with CFC 11 blowing agent, serve to maintain cryogenic propellant quality, maintain the external tank structural temperature limits, and minimize the formation of ice and frost that could potentially damage the ceramic insulation on the space shuttle orbiter. During flight the external tank insulations are exposed to mechanical, thermal and acoustical stresses. TPS must pass cryogenic flexure and substrate adhesion tests at -253 C, aerothermal and radiant heating tests at fluxes up to approximately 14 kilowatts per square meter, and thermal conductivity tests at cryogenic and elevated temperatures. Due to environmental concerns, the polyurethane insulation industry and the External Tank Project are tasked with replacing CFC 11. The flight qualification of foam insulations employing HCFC 141b as a foaming agent is currently in progress; HCFC 141b blown insulations are scheduled for production implementation in 1995. Realizing that the second generation HCFC blowing agents are an interim solution, the evaluation of third generation blowing agents with zero ozone depletion potential is underway. NASA's TPS Materials Research Laboratory is evaluating third generation blowing agents in cryogenic insulations for the External Tank; one option being investigated is the use of water as a foaming agent. A dimensionally stable insulation with low friability, good adhesion to cryogenic substrates, and acceptable thermal conductivity has been developed with low viscosity materials that are easily processed in molding applications. The development criteria, statistical experimental approach, and resulting foam properties will be presented.

  10. 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

  11. Cryogenic Insulation Standard Data and Methodologies Project

    Science.gov (United States)

    Summerfield, Burton; Thompson, Karen; Zeitlin, Nancy; Mullenix, Pamela; Fesmire, James; Swanger, Adam

    2015-01-01

    Extending some recent developments in the area of technical consensus standards for cryogenic thermal insulation systems, a preliminary Inter-Laboratory Study of foam insulation materials was performed by NASA Kennedy Space Center and LeTourneau University. The initial focus was ambient pressure cryogenic boil off testing using the Cryostat-400 flat-plate instrument. Completion of a test facility at LETU has enabled direct, comparative testing, using identical cryostat instruments and methods, and the production of standard thermal data sets for a number of materials under sub-ambient conditions. The two sets of measurements were analyzed and indicate there is reasonable agreement between the two laboratories. Based on cryogenic boiloff calorimetry, new equipment and methods for testing thermal insulation systems have been successfully developed. These boiloff instruments (or cryostats) include both flat plate and cylindrical models and are applicable to a wide range of different materials under a wide range of test conditions. Test measurements are generally made at large temperature difference (boundary temperatures of 293 K and 78 K are typical) and include the full vacuum pressure range. Results are generally reported in effective thermal conductivity (ke) and mean heat flux (q) through the insulation system. The new cryostat instruments provide an effective and reliable way to characterize the thermal performance of materials under subambient conditions. Proven in through thousands of tests of hundreds of material systems, they have supported a wide range of aerospace, industry, and research projects. Boiloff testing technology is not just for cryogenic testing but is a cost effective, field-representative methodology to test any material or system for applications at sub-ambient temperatures. This technology, when adequately coupled with a technical standards basis, can provide a cost-effective, field-representative methodology to test any material or system

  12. Insulator coated magnetic nanoparticulate composites with reduced core loss and method of manufacture thereof

    Science.gov (United States)

    Zhang, Yide (Inventor); Wang, Shihe (Inventor); Xiao, Danny (Inventor)

    2004-01-01

    A series of bulk-size magnetic/insulating nanostructured composite soft magnetic materials with significantly reduced core loss and its manufacturing technology. This insulator coated magnetic nanostructured composite is comprises a magnetic constituent, which contains one or more magnetic components, and an insulating constituent. The magnetic constituent is nanometer scale particles (1-100 nm) coated by a thin-layered insulating phase (continuous phase). While the intergrain interaction between the immediate neighboring magnetic nanoparticles separated by the insulating phase (or coupled nanoparticles) provide the desired soft magnetic properties, the insulating material provides the much demanded high resistivity which significantly reduces the eddy current loss. The resulting material is a high performance magnetic nanostructured composite with reduced core loss.

  13. Magnetically insulated H- diodes

    International Nuclear Information System (INIS)

    Fisher, A.; Bystritskii, V.; Garate, E.; Prohaska, R.; Rostoker, N.

    1993-01-01

    At the Univ. of California, Irvine, the authors have been studying the production of intense H - beams using pulse power techniques for the past 7 years. Previously, current densities of H - ions for various diode designs at UCI have been a few A/cm 2 . Recently, they have developed diodes similar to the coaxial design of the Lebedev Physical Institute, Moscow, USSR, where current densities of up to 200 A/cm 2 were reported using nuclear activation of a carbon target. In experiments at UCI employing the coaxial diode, current densities of up to 35 A/cm 2 from a passive polyethylene cathode loaded with TiH 2 have been measured using a pinhole camera and CR-39 track recording plastic. The authors have also been working on a self-insulating, annular diode which can generate a directed beam of H - ions. In the annular diode experiments a plasma opening switch was used to provide a prepulse and a current path which self-insulated the diode. These experiments were done on the machine APEX, a 1 MV, 50 ns, 7 Ω pulseline with a unipolar negative prepulse of ∼ 100 kV and 400 ns duration. Currently, the authors are modifying the pulseline to include an external LC circuit which can generate a bipolar, 150 kV, 1 μs duration prepulse (similar prepulse characteristic as in the Lebedev Institute experiments cited above)

  14. Distribution of Energy Deposited in Plastic Tubing and Copper-Wire Insulation by Electron Beam Irradiation

    DEFF Research Database (Denmark)

    Pedersen, Walther Batsberg; Miller, Arne; Pejtersen, K.

    1978-01-01

    chloride insulation. Radiochromic dye films equivalent to the insulating materials were used as accurate dosimeters having a response independent of dose rate. Irradiations were in various geometries, wire and plastic thicknesses, positions along the beam scan, and with different backing materials near...

  15. Surface electrical resistivity of insulators

    International Nuclear Information System (INIS)

    Senn, B. C.; Liesegang, J.

    1996-01-01

    A method is presented here for measuring surface charge decay, and theory has been developed so as to produce determinations of resistivity in the surface region of insulator films or wafers. This method incorporates the use of a coaxial cylindrical capacitor arrangement and an electrometer interfaced to a PC. The charge transport theory given here is based on Mott-Gurney diffusion, and allows easy interpretation of the experimental data, especially for the initial phase of surface charge decay. Resistivity measurements are presented for glass, mica, perspex and polyethylene, covering a range of 10 9 to 10 18 Ωm, as an illustration of the useful range of the instrument for static and antistatic materials, particularly in film or sheet form. Values for the surface charge diffusion constants of the materials are also presented. The charge transport theory has also been extended to allow the experimental and computational theoretical comparison of surface charge decay not only over the initial phase of charge decay, but also over longer times. The theoretical predictions show excellent agreement with experiment using the values for the diffusion constants referred to above

  16. Spintronics Based on Topological Insulators

    Science.gov (United States)

    Fan, Yabin; Wang, Kang L.

    2016-10-01

    Spintronics using topological insulators (TIs) as strong spin-orbit coupling (SOC) materials have emerged and shown rapid progress in the past few years. Different from traditional heavy metals, TIs exhibit very strong SOC and nontrivial topological surface states that originate in the bulk band topology order, which can provide very efficient means to manipulate adjacent magnetic materials when passing a charge current through them. In this paper, we review the recent progress in the TI-based magnetic spintronics research field. In particular, we focus on the spin-orbit torque (SOT)-induced magnetization switching in the magnetic TI structures, spin-torque ferromagnetic resonance (ST-FMR) measurements in the TI/ferromagnet structures, spin pumping and spin injection effects in the TI/magnet structures, as well as the electrical detection of the surface spin-polarized current in TIs. Finally, we discuss the challenges and opportunities in the TI-based spintronics field and its potential applications in ultralow power dissipation spintronic memory and logic devices.

  17. Conformally encapsulated multi-electrode arrays with seamless insulation

    Energy Technology Data Exchange (ETDEWEB)

    Tabada, Phillipe J.; Shah, Kedar G.; Tolosa, Vanessa; Pannu, Satinderall S.; Tooker, Angela; Delima, Terri; Sheth, Heeral; Felix, Sarah

    2016-11-22

    Thin-film multi-electrode arrays (MEA) having one or more electrically conductive beams conformally encapsulated in a seamless block of electrically insulating material, and methods of fabricating such MEAs using reproducible, microfabrication processes. One or more electrically conductive traces are formed on scaffold material that is subsequently removed to suspend the traces over a substrate by support portions of the trace beam in contact with the substrate. By encapsulating the suspended traces, either individually or together, with a single continuous layer of an electrically insulating material, a seamless block of electrically insulating material is formed that conforms to the shape of the trace beam structure, including any trace backings which provide suspension support. Electrical contacts, electrodes, or leads of the traces are exposed from the encapsulated trace beam structure by removing the substrate.

  18. Insulation systems for liquid methane fuel tanks for supersonic cruise aircraft

    Science.gov (United States)

    Brady, H. F.; Delduca, D.

    1972-01-01

    Two insulation systems for tanks containing liquid methane in supersonic cruise-type aircraft were designed and tested after an extensive materials investigation. One system is an external insulation and the other is an internal wet-type insulation system. Tank volume was maximized by making the tank shape approach a rectangular parallelopiped. One tank was designed to use the external insulation and the other tank to use the internal insulation. Performance of the external insulation system was evaluated on a full-scale tank under the temperature environment of -320 F to 700 F and ambient pressures of ground-level atmospheric to 1 psia. Problems with installing the internal insulation on the test tank prevented full-scale evaluation of performance; however, small-scale testing verified thermal conductivity, temperature capability, and installed density.

  19. Composite bulk Heat Insulation Made of loose Mineral and Organic Aggregate

    Directory of Open Access Journals (Sweden)

    Namsone Eva

    2015-12-01

    Full Text Available The task of building energy-efficiency is getting more important. Every house owner wishes to save up exploitation costs of heating, cooling, hot water production, ventilation, etc. and find cost-effective investments. One of the ways to reduce greenhouse gas emissions (GHGE is to minimize the heat transfer through the building by insulating it. Loose heat insulation is a good alternative to traditional board insulation, it is simple in use and cost-effective. Main drawback of this insulation is tendency to compact during exploitation. In the frame of this research composite loose heat insulation is elaborated, consisting on porous mineral foamed glass aggregate and local organic fiber materials (hemp and flaxen shives. Composite bulk insulation is an alternative solution which combines heat insulating properties and mechanical stability.

  20. Electron beam assisted field evaporation of insulating nanowires/tubes

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, N. P., E-mail: nicholas.blanchard@univ-lyon1.fr; Niguès, A.; Choueib, M.; Perisanu, S.; Ayari, A.; Poncharal, P.; Purcell, S. T.; Siria, A.; Vincent, P. [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne Cedex (France)

    2015-05-11

    We demonstrate field evaporation of insulating materials, specifically BN nanotubes and undoped Si nanowires, assisted by a convergent electron beam. Electron irradiation leads to positive charging at the nano-object's apex and to an important increase of the local electric field thus inducing field evaporation. Experiments performed both in a transmission electron microscope and in a scanning electron microscope are presented. This technique permits the selective evaporation of individual nanowires in complex materials. Electron assisted field evaporation could be an interesting alternative or complementary to laser induced field desorption used in atom probe tomography of insulating materials.

  1. Measure Guideline: Wall Air Sealing and Insulation Methods in Existing Homes; An Overview of Opportunity and Process

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, S.; Stephenson, R.

    2012-09-01

    This guide provides renovators and retrofit contractors an overview of considerations when including wall air sealing and insulation in an energy retrofit project. It also outlines the potential project risks, various materials for insulating, possible field inspections needed, installation procedures, as well as the benefits and drawbacks. The purpose of this document is to provide the outline of the overview and process of insulating and air sealing walls so that home retrofit professionals can identify approaches to air sealing and insulation measures.

  2. Development of radiation resistant PEEK insulation cable

    International Nuclear Information System (INIS)

    Mio, Keigo; Ogiwara, Norio; Hikichi, Yusuke; Furukori, Hisayoshi; Arai, Hideyuki; Nishizawa, Daiji; Nishidono, Toshiro

    2009-04-01

    Material characterization and development has been carried out for cable insulation suitable for use in the J-PARC 3-GeV RCS radiation environment. In spite of its high cost, PEEK (polyether-ether-ketone) has emerged as the leading candidate satisfying requirements of being non-halogen based, highly incombustible and with radiation resistant at least 10 MGy, along with the usual mechanical characteristics such as good elongation at break, which are needed in a cable insulation. Gamma-ray irradiation tests have been done in order to study radiation resistance of PEEK cable. Further, mechanical, electrical and fire retardant characteristics of a complete cable such as would be used at the J-PARC RCS were investigated. As a result, PEEK cables were shown to be not degraded by radiation up to at least 10 MGy, and thus could be expected to operate stably under the 3-GeV RCS radiation environment. (author)

  3. Magnetically self-insulated transformers

    International Nuclear Information System (INIS)

    Novac, B.M.; Smith, I.R.; Brown, J.

    2002-01-01

    Magnetic insulation is the only practicable form of insulation for much equipment used in ultrahigh pulsed-power work, including transmission lines and plasma opening switches. It has not however so far been successfully exploited in the transformers that are necessarily involved, and the first proposed design that appeared more than 30 years ago raised apparently insuperable problems. The two novel arrangements for a magnetically insulated transformer described in this paper overcome the problems faced by the earlier designs and also offer considerable scope for development in a number of important areas. Theoretical justification is given for their insulating properties, and this is confirmed by proof-of-principle results obtained from a small-scale experimental prototype in which magnetic insulation was demonstrated at up to 100 kV. (author)

  4. Structure, Mechanism, and Application of Vacuum Insulation Panels in Chinese Buildings

    OpenAIRE

    Peng, Changhai; Yang, Jianqiang

    2016-01-01

    Thermal insulation is one of the most used approaches to reduce energy consumption in buildings. Vacuum insulation panels (VIPs) are new thermal insulation materials that have been used in the domestic and overseas market in the last 20 years. Due to the vacuum thermal insulation technology of these new materials, their thermal conductivity can be as low as 0.004 W/(m·K) at the center of panels. In addition, VIPs that are composites with inorganic core and an envelope out of commonly three me...

  5. 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.

  6. Aerogel-Based Insulation for Industrial Steam Distribution Systems

    Energy Technology Data Exchange (ETDEWEB)

    John Williams

    2011-03-30

    Thermal losses in industrial steam distribution systems account for 977 trillion Btu/year in the US, more than 1% of total domestic energy consumption. Aspen Aerogels worked with Department of Energy’s Industrial Technologies Program to specify, develop, scale-up, demonstrate, and deliver Pyrogel XT®, an aerogel-based pipe insulation, to market to reduce energy losses in industrial steam systems. The product developed has become Aspen’s best selling flexible aerogel blanket insulation and has led to over 60 new jobs. Additionally, this product has delivered more than ~0.7 TBTU of domestic energy savings to date, and could produce annual energy savings of 149 TBTU by 2030. Pyrogel XT’s commercial success has been driven by it’s 2-4X better thermal performance, improved durability, greater resistance to corrosion under insulation (CUI), and faster installation times than incumbent insulation materials.

  7. The electric strength of high-voltage transformers insulation at effect of partial dischargers

    International Nuclear Information System (INIS)

    Khoshravan, E.; Zeraatparvar, A.; Gashimov, A.M.; Mehdizadeh, R.N.

    2001-01-01

    Full text : In paper the change of electric strength of high-voltage transformers insulation at the effect of partial discharges with space charge accumulation was investigated. It is revealed that the effect of partial discharges of insulation materials results the reduction of their pulsing electric strength which can restore the own initial value at releasing of saved charge the volume of a material under condition of absence the ineversible structural changes in it. Researches of high-voltage transformers insulation's non-failure operation conditions show, that at increasing of insulation work time in a strong electrical field the reduction of average breakdown voltages with simultaneous increasing of spread in discharge voltage values takes place. It authentically testifies to reduction of short-time discharge voltage of insulation materials during their electrical aging. As the basic reason of insulation electrical aging the partial discharges occurring in gas cavities inside insulation were considered. It is known that the space charges will be formed in insulation elements of high-voltage devices which effects in dielectrical property of these elements including the electric strength and the space charge formation can occur also at partial discharges in an alternating voltage while the service of high-voltage transformers. In the given work the experiments in revealing separate influence partial discharges in pulsing electric strength of insulation materials at presence and at absence inside them the space charge were spent

  8. Study on radiation resistance of electro insulating materials used in high-voltage equipment at Chernobylsk NPP; Issledovanie radiatsionnoj stojkosti ehlektroizolyatsionnykh materialov, primenyaemykh v vytsfsokovol`tnom oborudovanii na Chernobyl`skoj AEhS

    Energy Technology Data Exchange (ETDEWEB)

    Lizunov, S D [and others

    1994-12-31

    Investigations into the radiation resistance of the transformer oil and electro insulating cardboard during emergency irradiation at the NPP in 1986 are conducted. It is shown that as a result of transformer oil irradiation it is decomposed with the release of hydrogen, ethane, ethylene, ethane and other gases.

  9. Air insulated cables for medium and low voltage supplies of the EVU

    Energy Technology Data Exchange (ETDEWEB)

    Dienstel, S

    1977-02-01

    Air insulated cables and insulated overhead cables are electrical components, which, by the use of new insulating materials and technology, are particularly suitable for the introduction of systems for overhead power transmission plants. They combine the favorable properties of underground cables, such as compact construction and low inductance, with their high mechanical strength. The present report deals with the construction, accessories and technical properties of these cables. The constructional and operational aspects of such systems and their costs are also discussed.

  10. Irradiation effects on organic insulators

    International Nuclear Information System (INIS)

    Kasen, M.B.

    1986-01-01

    The overall objective of this work is to contribute to development of organic insulators having the cryogenic neutron irradiation resistance required for MFE systems utilizing superconducting magnet confinement. The system for producing standard 3.2-mm (0.125-in) diameter rod specimens discussed in previous reports has been further refined to permit the fabrication of both fiber-reinforced and heat-resin specimens from hot-melt resin systems. The method has been successfully used to produce very high quality specimens duplicating the G-11CR system and specimens from a variant of that system eliminating a boron-containing additive. We have also produced specimens from an epoxy system suitable for impregnation or potting operations and from a bismaleimide polyimide system. These materials will be used in the first irradiation program in the National Low Temperature Neutron Irradiation Facility (NLTNIF) reactor at Oak Ridge. We have refined the 4-K torsional shear test method for evaluating radiation degradation of the fiber-matrix interface and have developed a method of quantitatively measuring changes in fracture energy as a function of radiation dose. Cooperative work with laboratories in Japan and England in this area is continuing and plans are being formulated for joint production, irradiation, and testing of specimens

  11. Impact of moisture content in AAC on its heat insulation properties

    Science.gov (United States)

    Rubene, S.; Vilnitis, M.

    2017-10-01

    One of the most popular trends in construction industry is sustainable construction. Therefore, application of construction materials with high insulation characteristics has significantly increased during the past decade. Requirements for application of construction materials with high insulation parameters are required not only by means of energy saving and idea of sustainable construction but also by legislative requirements. Autoclaved aerated concrete (AAC) is a load bearing construction material, which has high heat insulation parameters. However, if the AAC masonry construction has high moisture content the heat insulation properties of the material decrease significantly. This fact lead to the necessity for the on-site control of moisture content in AAC in order to avoid inconsistency between the designed and actual thermal resistivity values of external delimiting constructions. Research of the impact of moisture content in AAC on its heat insulation properties has been presented in this paper.

  12. Similarity Analysis of Cable Insulations by Chemical Test

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Seog [Central Research Institute of Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2013-10-15

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials.

  13. Similarity Analysis of Cable Insulations by Chemical Test

    International Nuclear Information System (INIS)

    Kim, Jong Seog

    2013-01-01

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials

  14. Lightweight, Thermally Insulating Structural Panels

    Science.gov (United States)

    Eisen, Howard J.; Hickey, Gregory; Wen, Liang-Chi; Layman, William E.; Rainen, Richard A.; Birur, Gajanana C.

    1996-01-01

    Lightweight, thermally insulating panels that also serve as structural members developed. Honeycomb-core panel filled with low-thermal-conductivity, opacified silica aerogel preventing convection and minimizes internal radiation. Copper coating on face sheets reduces radiation. Overall thermal conductivities of panels smaller than state-of-art commercial non-structurally-supporting foam and fibrous insulations. On Earth, panels suitable for use in low-air-pressure environments in which lightweight, compact, structurally supporting insulation needed; for example, aboard high-altitude aircraft or in partially evacuated panels in refrigerators.

  15. Reflecting variable opening insulating panel

    International Nuclear Information System (INIS)

    Nungesser, W.T.

    1976-01-01

    A description is given of a reflecting variable opening insulating panel assembly, comprising a static panel assembly of reflecting insulation sheets forming a cavity along one side of the panel and a movable panel opening out by sliding from the cavity of the static panel, and a locking device for holding the movable panel in a position extending from the cavity of the static panel. This can apply to a nuclear reactor of which the base might require maintenance and periodical checking and for which it is desirable to have available certain processes for the partial dismantling of the insulation [fr

  16. Fabrication of insulator nanocapillaries from diatoms

    International Nuclear Information System (INIS)

    Bereczky, R.J.; Tokesi, K.

    2006-01-01

    Complete text of publication follows. Diatoms are unicellular microscopic organisms with silicon-dioxide based skeleton enveloped with an organic material, which composes essentially polysaccharides and proteins (see Fig. 1a.). As it was shown, the valva of the diatoms build up almost from clean silicondioxide [1]. Therefore, removing the organic compounds from the diatom, we can have in our hand an ideal, about 100 μ m-sized, and almost cylindrical shaped insulating nanostructure. There are various techniques available to disembarrass the diatom from its organic compounds. We used the so called hydrogen peroxide method. The advantageous properties of this method are the followings: a) this is one of the fastest procedures among the possible methods, b) do not require special equipment, c) cheap, and last but not least it is less harmful for health compared to other methods. This procedure can be an alternative way of the fabrication of insulator nanocapillaries. In this case the preparation of the nanocapillaries is simple and quick. Moreover, we do not need to invest expensive special techniques, (like micromachining-, electrochemical etching technique, moulding process etc) as it was necessary for the case of previously developed method producing insulator nanocapillaries [2,3]. Fig. 1b and Fig. 1c. show the scanning electron micrograph of the skeleton of the diatoms. The size of the cylindrical holes are roughly 200 nm (see Fig. 1c). (author)

  17. Hygrothermal Properties and Performance of Sea Grass Insulation

    DEFF Research Database (Denmark)

    Eriksen, Marlene Stenberg Hagen; Laursen, Theresa Back; Rode, Carsten

    2008-01-01

    In the attempt to obtain knowledge of the hygrothermal properties of sea grass as thermal insulation, experiments have been carried out in the laboratory to determine the thermal conductivity, sorption properties and the water vapour permeability of the material. In order to investigate the hygro......In the attempt to obtain knowledge of the hygrothermal properties of sea grass as thermal insulation, experiments have been carried out in the laboratory to determine the thermal conductivity, sorption properties and the water vapour permeability of the material. In order to investigate...

  18. Superconductivity and ferromagnetism in topological insulators

    Science.gov (United States)

    Zhang, Duming

    Topological insulators, a new state of matter discovered recently, have attracted great interest due to their novel properties. They are insulating inside the bulk, but conducting at the surface or edges. This peculiar behavior is characterized by an insulating bulk energy gap and gapless surface or edge states, which originate from strong spin-orbit coupling and time-reversal symmetry. The spin and momentum locked surface states not only provide a model system to study fundamental physics, but can also lead to applications in spintronics and dissipationless electronics. While topological insulators are interesting by themselves, more exotic behaviors are predicted when an energy gap is induced at the surface. This dissertation explores two types of surface state gap in topological insulators, a superconducting gap induced by proximity effect and a magnetic gap induced by chemical doping. The first three chapters provide introductory theory and experimental details of my research. Chapter 1 provides a brief introduction to the theoretical background of topological insulators. Chapter 2 is dedicated to material synthesis principles and techniques. I will focus on two major synthesis methods: molecular beam epitaxy for the growth of Bi2Se3 thin films and chemical vapor deposition for the growth of Bi2Se3 nanoribbons and nanowires. Material characterization is discussed in Chapter 3. I will describe structural, morphological, magnetic, electrical, and electronic characterization techniques used to study topological insulators. Chapter 4 discusses the experiments on proximity-induced superconductivity in topological insulator (Bi2Se3) nanoribbons. This work is motivated by the search for the elusive Majorana fermions, which act as their own antiparticles. They were proposed by Ettore Majorara in 1937, but have remained undiscovered. Recently, Majorana's concept has been revived in condensed matter physics: a condensed matter analog of Majorana fermions is predicted to

  19. Thermic insulation in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Nicolaon, G. (Ambassade de France a New York (USA)); Atlas, O. (Illinois Institute of Technology, Chicago, (USA))

    1984-01-30

    At present, thermic insulation accounts for 13% of the savings which have been made and this percentage should increase substantially in the future. The ideal insulation material must have low thermic conductivity, but also be light, have a low dilatation coefficient, good mechanical resistance and be fireproof and non-toxic. Rock wool and above all glass wool have the major portion in the insulation market with about 75% of the total. The prospects for an increase in sales are average: 6 to 7% per year until 1990 with a stabilization or a decrease after this date. Production is concentrated in the hands of about ten producers. The insulation with a cellulose base -with the addition of a combustion inhibitor, usually borax- represent about 15% of the market. Manufacturers are numerous and the production units are small. Any serious evaluation of the future of this product is difficult to make. However, it should be noted that combustion inhibition is one of the main factors of success of this product and constitutes a relatively active field of research. Perlite and vermiculite have a marginal part of the market which is concentrated in the hands of a few dozen producers. Their future seems promising and their production should double between now and the end of the century. There is also the field of plastics which has to be considered and notably polystyrene, polyurethanes and polyisocyanates. These can be injected and moulded in situ. To the extent that toxicity studies can definitively conclude that they are not harmful (urea-formol resins have just been prohibited), their future is brillant and their growth rate could reach about 200% per year. The big chemical and pharmaceutical companies are interested in these products and their portion of the market can rapidly go beyond their present 6 to 8%.

  20. Metal-insulator transition in vanadium dioxide

    International Nuclear Information System (INIS)

    Zylbersztejn, A.; Mott, N.F.

    1975-01-01

    The basic physical parameters which govern the metal-insulator transition in vanadium dioxide are determined through a review of the properties of this material. The major importance of the Hubbard intra-atomic correlation energy in determining the insulating phase, which was already evidence by studies of the magnetic properties of V 1 -/subx/Cr/subx/O 2 alloys, is further demonstrated from an analysis of their electrical properties. An analysis of the magnetic susceptibility of niobium-doped VO 2 yields a picture for the current carrier in the low-temperature phase in which it is accompanied by a spin cloud (owing to Hund's-rule coupling), and has therefore an enhanced mass (m approx. = 60m 0 ). Semiconducting vanadium dioxide turns out to be a borderline case for a classical band-transport description; in the alloys at high doping levels, Anderson localization with hopping transport can take place. Whereas it is shown that the insulating phase cannot be described correctly without taking into account the Hubbard correlation energy, we find that the properties of the metallic phase are mainly determined by the band structure. Metallic VO 2 is, in our view, similar to transition metals like Pt or Pd: electrons in a comparatively wide band screening out the interaction between the electrons in a narrow overlapping band. The magnetic susceptibility is described as exchange enhanced. The large density of states at the Fermi level yields a substantial contribution of the entropy of the metallic electrons to the latent heat. The crystalline distortion removes the band degeneracy so that the correlation energy becomes comparable with the band width and a metal-insulator transition takes place

  1. Aharonov–Bohm interference in topological insulator nanoribbons

    KAUST Repository

    Peng, Hailin

    2009-12-13

    Topological insulators represent unusual phases of quantum matter with an insulating bulk gap and gapless edges or surface states. The two-dimensional topological insulator phase was predicted in HgTe quantum wells and confirmed by transport measurements. Recently, Bi2 Se3 and related materials have been proposed as three-dimensional topological insulators with a single Dirac cone on the surface, protected by time-reversal symmetry. The topological surface states have been observed by angle-resolved photoemission spectroscopy experiments. However, few transport measurements in this context have been reported, presumably owing to the predominance of bulk carriers from crystal defects or thermal excitations. Here we show unambiguous transport evidence of topological surface states through periodic quantum interference effects in layered single-crystalline Bi2 Se3 nanoribbons, which have larger surface-to-volume ratios than bulk materials and can therefore manifest surface effects. Pronounced Aharonov-Bohm oscillations in the magnetoresistance clearly demonstrate the coherent propagation of two-dimensional electrons around the perimeter of the nanoribbon surface, as expected from the topological nature of the surface states. The dominance of the primary h/e oscillation, where h is Plancks constant and e is the electron charge, and its temperature dependence demonstrate the robustness of these states. Our results suggest that topological insulator nanoribbons afford promising materials for future spintronic devices at room temperature.

  2. Thin Aerogel as a Spacer in Multilayer Insulation

    Science.gov (United States)

    Moroz, Nancy

    2015-01-01

    Cryogenic fluid management is a critical technical area that is needed for future space exploration. A key challenge is the storability of liquid hydrogen (LH2), liquid methane (LCH4), and liquid oxygen (LOX) propellants for long-duration missions. The storage tanks must be well-insulated to prevent over-pressurization and venting, which can lead to unacceptable propellant losses for long-duration missions to Mars and beyond. Aspen Aerogels had validated the key process step to enable the fabrication of thin, low-density aerogel materials. The multilayer aerogel insulation (MLAI) system prototypes were prepared using sheets of aerogel materials with superior thermal performance exceeding current state-of-the-art insulation for space applications. The exceptional properties of this system include a new breakthrough in high-vacuum cryogenic thermal insulation, providing a durable material with excellent thermal performance at a reduced cost when compared to longstanding state-of-the-art multilayer insulation systems. During the Phase II project, further refinement and qualification/system-level testing of the MLAI system will be performed for use in cryogenic storage applications. Aspen has been in discussions with United Launch Alliance, LLC; NASA's Kennedy Space Center; and Yetispace, Inc., to test the MLAI system on rea-lworld tanks such as Vibro-Acoustic Test Article (VATA) or the Cryogenic Orbital Testbed (CRYOTE).

  3. Vacuum insulation panels for building applications: A review and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Baetens, Ruben [Department of Building Materials and Structures, SINTEF Building and Infrastructure, NO-7465 Trondheim (Norway); Department of Civil and Transport Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Laboratory of Building Physics, Department of Civil Engineering, Catholic University of Leuven (KUL), BE-3001 Heverlee (Belgium); Jelle, Bjoern Petter [Department of Building Materials and Structures, SINTEF Building and Infrastructure, NO-7465 Trondheim (Norway); Department of Civil and Transport Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Thue, Jan Vincent [Department of Civil and Transport Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Tenpierik, Martin J. [Faculty of Architecture, Urbanism and Building Sciences, Delft University of Technology, Julianalaan 134, 2628 BL Delft (Netherlands); Grynning, Steinar; Uvsloekk, Sivert [Department of Building Materials and Structures, SINTEF Building and Infrastructure, NO-7465 Trondheim (Norway); Gustavsen, Arild [Department of Architectural Design, History and Technology, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway)

    2010-02-15

    Vacuum insulation panels (VIPs) are regarded as one of the most promising high performance thermal insulation solutions on the market today. Thermal performances three to six times better than still-air are achieved by applying a vacuum to an encapsulated micro-porous material, resulting in a great potential for combining the reduction of energy consumption in buildings with slim constructions. However, thermal bridging due to the panel envelope and degradation of thermal performance through time occurs with current technology. Furthermore, VIPs cannot be cut on site and the panels are fragile towards damaging. These effects have to be taken into account for building applications as they may diminish the overall usability and thermal performance. This paper is as far as the authors know the first comprehensive review on VIPs. Properties, requirements and possibilities of foil encapsulated VIPs for building applications are studied based on available literature, emphasizing thermal bridging and degradation through time. An extension is made towards gas-filled panels and aerogels, showing that other high performance thermal insulation solutions do exist. Combining the technology of these solutions and others may lead to a new leap forward. Feasible paths beyond VIPs are investigated and possibilities such as vacuum insulation materials (VIMs) and nano insulation materials (NIMs) are proposed. (author)

  4. Development and validation of cryogenic foam insulation for LH2 subsonic transports

    Science.gov (United States)

    Anthony, F. M.; Colt, J. Z.; Helenbrook, R. G.

    1981-01-01

    Fourteen foam insulation specimens were tested. Some were plain foam while others contained flame retardants, chopped fiberglass reinforcement and/or vapor barriers. The thermal performance of the insulation was determined by measuring the rate at which LH2 boiled from an aluminum tank insulated with the test material. The test specimens were approximately 50 mm (2 in.) thick. They were structurally scaled so that the test cycle would duplicate the maximum thermal stresses predicted for the thicker insulation of an aircraft liquid hydrogen fuel tank during a typical subsonic flight. The simulated flight cycle of approximately 10 minutes duration heated the other insulation surface to 316 K (110 F) and cooled it to 226 K (20 F) while the inner insulation surface remained at liquid hydrogen temperature of 20 K (-423 F). Two urethane foam insulations exceeded the initial life goal of 2400 simulated flight cycles and sustained 4400 cycles with only minor damage. The addition of fiberglass reinforcement of flame retardant materials to an insulation degraded thermal performance and/or the life of the foam material. Installation of vapor barriers enhanced the structural integrity of the material but did not improve thermal performance. All of the foams tested were available materials; none were developed specifically for LH2 service.

  5. Molecular dewetting on insulators

    International Nuclear Information System (INIS)

    Burke, S A; Topple, J M; Gruetter, P

    2009-01-01

    Recent attention given to the growth and morphology of organic thin films with regard to organic electronics has led to the observation of dewetting (a transition from layer(s) to islands) of molecular deposits in many of these systems. Dewetting is a much studied phenomenon in the formation of polymer and liquid films, but its observation in thin films of the 'small' molecules typical of organic electronics requires additional consideration of the structure of the interface between the molecular film and the substrate. This review covers some key concepts related to dewetting and molecular film growth. In particular, the origins of different growth modes and the thickness dependent interactions which give rise to dewetting are discussed in terms of surface energies and the disjoining pressure. Characteristics of molecular systems which may lead to these conditions, including the formation of metastable interface structures and commensurate-incommensurate phase transitions, are also discussed. Brief descriptions of some experimental techniques which have been used to study molecular dewetting are given as well. Examples of molecule-on-insulator systems which undergo dewetting are described in some detail, specifically perylene derivatives on alkali halides, C 60 on alkali halides, and the technologically important system of pentacene on SiO 2 . These examples point to some possible predicting factors for the occurrence of dewetting, most importantly the formation of an interface layer which differs from the bulk crystal structure. (topical review)

  6. Molecular dewetting on insulators.

    Science.gov (United States)

    Burke, S A; Topple, J M; Grütter, P

    2009-10-21

    Recent attention given to the growth and morphology of organic thin films with regard to organic electronics has led to the observation of dewetting (a transition from layer(s) to islands) of molecular deposits in many of these systems. Dewetting is a much studied phenomenon in the formation of polymer and liquid films, but its observation in thin films of the 'small' molecules typical of organic electronics requires additional consideration of the structure of the interface between the molecular film and the substrate. This review covers some key concepts related to dewetting and molecular film growth. In particular, the origins of different growth modes and the thickness dependent interactions which give rise to dewetting are discussed in terms of surface energies and the disjoining pressure. Characteristics of molecular systems which may lead to these conditions, including the formation of metastable interface structures and commensurate-incommensurate phase transitions, are also discussed. Brief descriptions of some experimental techniques which have been used to study molecular dewetting are given as well. Examples of molecule-on-insulator systems which undergo dewetting are described in some detail, specifically perylene derivatives on alkali halides, C(60) on alkali halides, and the technologically important system of pentacene on SiO(2). These examples point to some possible predicting factors for the occurrence of dewetting, most importantly the formation of an interface layer which differs from the bulk crystal structure.

  7. Insulating fcc YH

    International Nuclear Information System (INIS)

    Molen, S. J. van der; Nagengast, D. G.; Gogh, A. T. M. van; Kalkman, J.; Kooij, E. S.; Rector, J. H.; Griessen, R.

    2001-01-01

    We study the structural, optical, and electrical properties of Mg z Y 1-z switchable mirrors upon hydrogenation. It is found that the alloys disproportionate into essentially pure YH 3-δ and MgH 2 with the crystal structure of YH 3-δ dependent on the Mg concentration z. For 0 3-δ are observed, whereas for z≥0.1 only cubic YH 3-δ is present. Interestingly, cubic YH 3-δ is expanded compared to YH 2 , in disagreement with theoretical predictions. From optical and electrical measurements we conclude that cubic YH 3-δ is a transparent insulator with properties similar to hexagonal YH 3-δ . Our results are inconsistent with calculations predicting fcc YH 3-δ to be metallic, but they are in good agreement with recent GW calculations on both hcp and fcc YH 3 . Finally, we find an increase in the effective band gap of the hydrided Mg z Y 1-z alloys with increasing z. Possibly this is due to quantum confinement effects in the small YH 3 clusters

  8. Measure Guideline: Basement Insulation Basics

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R.; Mantha, P.; Puttagunta, S.

    2012-10-01

    This guideline is intended to describe good practices for insulating basements in new and existing homes, and is intended to be a practical resources for building contractors, designers, and also to homeowners.

  9. Metal-insulator-semiconductor photodetectors.

    Science.gov (United States)

    Lin, Chu-Hsuan; Liu, Chee Wee

    2010-01-01

    The major radiation of the sun can be roughly divided into three regions: ultraviolet, visible, and infrared light. Detection in these three regions is important to human beings. The metal-insulator-semiconductor photodetector, with a simpler process than the pn-junction photodetector and a lower dark current than the MSM photodetector, has been developed for light detection in these three regions. Ideal UV photodetectors with high UV-to-visible rejection ratio could be demonstrated with III-V metal-insulator-semiconductor UV photodetectors. The visible-light detection and near-infrared optical communications have been implemented with Si and Ge metal-insulator-semiconductor photodetectors. For mid- and long-wavelength infrared detection, metal-insulator-semiconductor SiGe/Si quantum dot infrared photodetectors have been developed, and the detection spectrum covers atmospheric transmission windows.

  10. Metal-Insulator-Semiconductor Photodetectors

    Directory of Open Access Journals (Sweden)

    Chu-Hsuan Lin

    2010-09-01

    Full Text Available The major radiation of the Sun can be roughly divided into three regions: ultraviolet, visible, and infrared light. Detection in these three regions is important to human beings. The metal-insulator-semiconductor photodetector, with a simpler process than the pn-junction photodetector and a lower dark current than the MSM photodetector, has been developed for light detection in these three regions. Ideal UV photodetectors with high UV-to-visible rejection ratio could be demonstrated with III-V metal-insulator-semiconductor UV photodetectors. The visible-light detection and near-infrared optical communications have been implemented with Si and Ge metal-insulator-semiconductor photodetectors. For mid- and long-wavelength infrared detection, metal-insulator-semiconductor SiGe/Si quantum dot infrared photodetectors have been developed, and the detection spectrum covers atmospheric transmission windows.

  11. Insulation system in an integrated motor compressor

    Energy Technology Data Exchange (ETDEWEB)

    Sihvo, V.

    2010-07-01

    natural gas is discussed based on a vast set of experimental tests with the gas mixture representing the real gas mixture at the wellhead. The mixture was created by mixing dry hydrocarbon gas, heavy hydrocarbon compounds, monoethylene glycol, and water. The mixture was chosen to be more aggressive by increasing the amount of liquid substances. Furthermore, the temperature and pressure were increased, which resulted in accelerated test conditions. The time required to detect severe degradation was thus decreased. The test program included a comparison of materials, an analysis of the effects of different compounds in the gas mixture, namely water and heavy hydrocarbons, on the aging, an analysis of the effects of temperature and exposure duration, and also an analysis on the e ect of sudden pressure changes on the degradation of the insulating materials. It was found in the tests that an insulation consisting of mica, glass, and epoxy resin can tolerate the raw natural gas, but it experiences some degradation. The key material in the composite insulation is the resin, which largely defines the performance of the insulation system. The degradation of the insulation is mostly determined by the amount of gas mixture diffused into it. The diffusion was seen to follow Fick's second law, but the coefficients were not accurately defined. The diffusion was not sensitive to temperature, but it was dependent upon the thermodynamic state of the gas mixture, in other words, the amounts of liquid components in the gas. The weight increase observed was mostly related to heavy hydrocarbon compounds, which act as plasticizers in the epoxy resin. The diffusion of these compounds is determined by the crosslink density of the resin. Water causes slight changes in the chemical structure, but these changes do not significantly contribute to the aging phenomena. Sudden changes in pressure can lead to severe damages in the insulation, because the motion of the di used gas is able to create

  12. Dirac materials

    OpenAIRE

    Wehling, T. O.; Black-Schaffer, A. M.; Balatsky, A. V.

    2014-01-01

    A wide range of materials, like d-wave superconductors, graphene, and topological insulators, share a fundamental similarity: their low-energy fermionic excitations behave as massless Dirac particles rather than fermions obeying the usual Schrodinger Hamiltonian. This emergent behavior of Dirac fermions in condensed matter systems defines the unifying framework for a class of materials we call "Dirac materials''. In order to establish this class of materials, we illustrate how Dirac fermions ...

  13. 16 CFR 460.18 - Insulation ads.

    Science.gov (United States)

    2010-01-01

    ... Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES LABELING AND ADVERTISING OF HOME INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation and... your ad gives a price, you must give the type of insulation, the R-value at a specific thickness, the...

  14. BOA: Pipe asbestos insulation removal robot system

    International Nuclear Information System (INIS)

    Schempf, H.; Bares, J.; Schnorr, W.

    1995-01-01

    The BOA system is a mobile pipe-external robotic crawler used to remotely strip and bag asbestos-containing lagging and insulation materials (ACLIM) from various diameter pipes in (primarily) industrial installations. Steam and process lines within the DOE weapons complex warrant the use of a remote device due to the high labor costs and high level of radioactive contamination, making manual removal extremely costly and highly inefficient. Currently targeted facilities for demonstration and remediation are Fernald in Ohio and Oak Ridge in Tennessee

  15. Solar Storage Tank Insulation Influence on the Solar Systems Efficiency

    Directory of Open Access Journals (Sweden)

    Negoitescu Arina

    2012-09-01

    Full Text Available For the storage tank of a solar system for domestic hot water production was analyzed the insulation thickness and material influence. To this end, it was considered a private house, occupied by 3 persons, located in zone I of thermal radiation, for which has been simulated the domestic hot water production process. The tank outlet hot water temperature was considered of 45°C. For simulation purposes, as insulation materials for the storage tank were taking into account glass wool and polyurethane with various thicknesses. Finally, was carried out the comparative analysis of two types of tanks, in terms of the insulation thickness influence on the solar fraction, annual solar contribution and solar annual productivity. It resulted that polyurethane is the most advantageous from all points of view.

  16. Retrofit with Interior Insulation on Solid Masonry Walls in Cool Temperate Climates

    DEFF Research Database (Denmark)

    Bjarløv, Søren Peter; Finken, G.R.; Odgaard, Tommy

    2015-01-01

    For historic buildings, where an alteration of the exterior façade is not wanted, interior insulation can be the solution to improve the indoor climate and reduce heat loss, but might also introduce moisture problems like condensation in the wall. Capillary active/hydrophilic insulation materials...... have been introduced to cope with the moisture problem. An extensive amount of calculations indicating where the challenges lie in the complex work with interior insulation in cool temperate climate has been carried out. In areas with high precipitation like Denmark, capillary active insulation may...

  17. Avalanches in insulating gases

    International Nuclear Information System (INIS)

    Verhaart, H.F.A.

    1982-01-01

    Avalanches of charged particles in gases are often studied with the ''electrical method'', the measurement of the waveform of the current in the external circuit. In this thesis a substantial improvement of the time resolution of the measuring setup, to be used for the electrical method, is reported. The avalanche is started by an N 2 -laser with a pulse duration of only 0.6 ns. With this laser it is possible to release a high number of primary electrons (some 10 8 ) which makes it possible to obtain sizeable signals, even at low E/p values. With the setup it is possible to analyze current waveforms with a time resolution down to 1.4 ns, determined by both the laser and the measuring system. Furthermore it is possible to distinguish between the current caused by the electrons and the current caused by the ions in the avalanche and to monitor these currents simultaneously. Avalanche currents are measured in N 2 , CO 2 , O 2 , H 2 O, air of varying humidity, SF 6 and SF 6 /N 2 mixtures. Depending on the nature of the gas and the experimental conditions, processes as diffusion, ionization, attachment, detachment, conversion and secondary emission are observed. Values of parameters with which these processes can be described, are derived from an analysis of the current waveforms. For this analysis already published theories and new theories described in this thesis are used. The drift velocity of both the electrons and the ions could be easily determined from measured avalanche currents. Special attention is paid to avalanches in air becasue of the practical importance of air insulation. (Auth.)

  18. 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

  19. The topological Anderson insulator phase in the Kane-Mele model

    Science.gov (United States)

    Orth, Christoph P.; Sekera, Tibor; Bruder, Christoph; Schmidt, Thomas L.

    2016-04-01

    It has been proposed that adding disorder to a topologically trivial mercury telluride/cadmium telluride (HgTe/CdTe) quantum well can induce a transition to a topologically nontrivial state. The resulting state was termed topological Anderson insulator and was found in computer simulations of the Bernevig-Hughes-Zhang model. Here, we show that the topological Anderson insulator is a more universal phenomenon and also appears in the Kane-Mele model of topological insulators on a honeycomb lattice. We numerically investigate the interplay of the relevant parameters, and establish the parameter range in which the topological Anderson insulator exists. A staggered sublattice potential turns out to be a necessary condition for the transition to the topological Anderson insulator. For weak enough disorder, a calculation based on the lowest-order Born approximation reproduces quantitatively the numerical data. Our results thus considerably increase the number of candidate materials for the topological Anderson insulator phase.

  20. A Network Model for the Effective Thermal Conductivity of Rigid Fibrous Refractory Insulations

    Science.gov (United States)

    Marschall, Jochen; Cooper, D. M. (Technical Monitor)

    1995-01-01

    A procedure is described for computing the effective thermal conductivity of a rigid fibrous refractory insulation. The insulation is modeled as a 3-dimensional Cartesian network of thermal conductance. The values and volume distributions of the conductance are assigned to reflect the physical properties of the insulation, its constituent fibers, and any permeating gas. The effective thermal conductivity is computed by considering the simultaneous energy transport by solid conduction, gas conduction and radiation through a cubic volume of model insulation; thus the coupling between heat transfer modes is retained (within the simplifications inherent to the model), rather than suppressed by treating these heat transfer modes as independent. The model takes into account insulation composition, density and fiber anisotropy, as well as the geometric and material properties of the constituent fibers. A relatively good agreement, between calculated and experimentally derived thermal conductivity values, is obtained for a variety of rigid fibrous insulations.

  1. Electric cable insulation pyrolysis and ignition resulting from potential hydrogen burn scenarios for nuclear containment buildings

    International Nuclear Information System (INIS)

    Berlad, A.L.; Jaung, R.; Pratt, W.T.

    1982-01-01

    Electric cable insulation in nuclear containment buildings may participate in pyrolysis and combustion processes engendered by hydrogen burn phenomena. This paper examines these pyrolysis/ignition processes of those polymeric materials present in the electric cable insulation and their possible relation to hydrogen burn scenarios

  2. Photoinduced Topological Phase Transitions in Topological Magnon Insulators.

    Science.gov (United States)

    Owerre, S A

    2018-03-13

    Topological magnon insulators are the bosonic analogs of electronic topological insulators. They are manifested in magnetic materials with topologically nontrivial magnon bands as realized experimentally in a quasi-two-dimensional (quasi-2D) kagomé ferromagnet Cu(1-3, bdc), and they also possess protected magnon edge modes. These topological magnetic materials can transport heat as well as spin currents, hence they can be useful for spintronic applications. Moreover, as magnons are charge-neutral spin-1 bosonic quasiparticles with a magnetic dipole moment, topological magnon materials can also interact with electromagnetic fields through the Aharonov-Casher effect. In this report, we study photoinduced topological phase transitions in intrinsic topological magnon insulators in the kagomé ferromagnets. Using magnonic Floquet-Bloch theory, we show that by varying the light intensity, periodically driven intrinsic topological magnetic materials can be manipulated into different topological phases with different sign of the Berry curvatures and the thermal Hall conductivity. We further show that, under certain conditions, periodically driven gapped topological magnon insulators can also be tuned to synthetic gapless topological magnon semimetals with Dirac-Weyl magnon cones. We envision that this work will pave the way for interesting new potential practical applications in topological magnetic materials.

  3. Impact Verification of Aerogel Insulation Paint on Historic Brick Facades

    Science.gov (United States)

    Ganobjak, Michal; Kralova, Eva

    2017-10-01

    Increasing the sustainability of existing buildings is being motivated by reduction of their energy demands. It is the above all the building envelope and its refurbishment by substitution or addition of new materials that makes the opportunity for reduction of energy consumption. A special type of refurbishment is conservation of historical buildings. Preservation of historic buildings permits also application of innovative methods and materials in addition to the original materials if their effects are known and the gained experience ensures their beneficial effect. On the market, there are new materials with addition of silica aerogel in various forms of products. They are also potentially useful in conservation of monuments. However, the effects of aerogel application in these cases are not known. For refurbishment is commercially available additional transparent insulation paint - Nansulate Clear Coat which is containing aerogel and can be used for structured surfaces such as bricks. A series of experiments examined the thermo-physical manifestation of an ultra-thin insulation coating of Nansulate Clear Coat containing silica aerogel on a brick facade. The experiments of active and passive thermography have observed effects of application on the small-scale samples of the brick façade of a protected historical building. Through a series of experiments were measured thermal insulation effect and influence on the aesthetic characteristics such as change in colour and gloss. The treated samples were compared to a reference. Results have shown no thermal-insulating manifestation of the recommended three layers of insulation paint. The three layers recommended by the manufacturer did not significantly affect the appearance of the brick facade. Color and gloss were not significantly changed. Experiments showed the absence of thermal insulation effect of Nansulate transparent triple coating. The thermal insulation effect could likely be reached by more layers of

  4. Industrial manufacturing of electric insulators; Fabricacion industrial de aisladores electricos

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Lucia [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    Porcelain is the insulating material more extensively used for electric insulators manufacturing, due to its dielectric properties; nevertheless, it presents fragility problems of manufacture and of resistance to the thermal shock, among others. For this reason studies are being conducted for the substitution of porcelain in the electric insulators manufacturing. In this area, the Instituto de Investigaciones Electricas developed an improved insulating formulation - the polymeric concrete- and an industrial prototype machine for the manufacture of high voltage electric insulators for outdoors use. [Espanol] La porcelana es el material aislante electrico mas utilizado en la elaboracion de aisladores electricos, debido a sus propiedades dielectricas; sin embargo, presenta problemas de fragilidad, de fabricacion y de baja resistencia al choque termico, entre otros. Es por ello que se realizan estudios para sustituir la porcelana en la fabricacion de aisladores electricos. En este campo, el Instituto de Investigaciones Electricas desarrollo una formulacion aislante mejorada -el concreto polimerico- y una maquina prototipo industrial para fabricar aisladores electricos de alto voltaje para uso en exteriores.

  5. Industrial manufacturing of electric insulators; Fabricacion industrial de aisladores electricos

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Lucia [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    Porcelain is the insulating material more extensively used for electric insulators manufacturing, due to its dielectric properties; nevertheless, it presents fragility problems of manufacture and of resistance to the thermal shock, among others. For this reason studies are being conducted for the substitution of porcelain in the electric insulators manufacturing. In this area, the Instituto de Investigaciones Electricas developed an improved insulating formulation - the polymeric concrete- and an industrial prototype machine for the manufacture of high voltage electric insulators for outdoors use. [Espanol] La porcelana es el material aislante electrico mas utilizado en la elaboracion de aisladores electricos, debido a sus propiedades dielectricas; sin embargo, presenta problemas de fragilidad, de fabricacion y de baja resistencia al choque termico, entre otros. Es por ello que se realizan estudios para sustituir la porcelana en la fabricacion de aisladores electricos. En este campo, el Instituto de Investigaciones Electricas desarrollo una formulacion aislante mejorada -el concreto polimerico- y una maquina prototipo industrial para fabricar aisladores electricos de alto voltaje para uso en exteriores.

  6. An Insulating Glass Knowledge Base

    Energy Technology Data Exchange (ETDEWEB)

    Michael L. Doll; Gerald Hendrickson; Gerard Lagos; Russell Pylkki; Chris Christensen; Charlie Cureija

    2005-08-01

    This report will discuss issues relevant to Insulating Glass (IG) durability performance by presenting the observations and developed conclusions in a logical sequential format. This concluding effort discusses Phase II activities and focuses on beginning to quantifying IG durability issues while continuing the approach presented in the Phase I activities (Appendix 1) which discuss a qualitative assessment of durability issues. Phase II developed a focus around two specific IG design classes previously presented in Phase I of this project. The typical box spacer and thermoplastic spacer design including their Failure Modes and Effect Analysis (FMEA) and Fault Tree diagrams were chosen to address two currently used IG design options with varying components and failure modes. The system failures occur due to failures of components or their interfaces. Efforts to begin quantifying the durability issues focused on the development and delivery of an included computer based IG durability simulation program. The focus/effort to deliver the foundation for a comprehensive IG durability simulation tool is necessary to address advancements needed to meet current and future building envelope energy performance goals. This need is based upon the current lack of IG field failure data and the lengthy field observation time necessary for this data collection. Ultimately, the simulation program is intended to be used by designers throughout the current and future industry supply chain. Its use is intended to advance IG durability as expectations grow around energy conservation and with the growth of embedded technologies as required to meet energy needs. In addition the tool has the immediate benefit of providing insight for research and improvement prioritization. Included in the simulation model presentation are elements and/or methods to address IG materials, design, process, quality, induced stress (environmental and other factors), validation, etc. In addition, acquired data

  7. Electrical insulators for the theta-pinch fusion reactor

    International Nuclear Information System (INIS)

    Clinard, F.W. Jr.

    1976-01-01

    The five major applications for electrical insulators in the Reference Theta Pinch Reactor are as follows: (1) first-wall insulator, (2) blanket intersegment insulator, (3) graphite encapsulating insulator, (4) implosion coil insulator, and (5) compression coil insulator. Insulator design proposals and some preliminary test results are given for each application

  8. Absorbed Dose Distributions in Irradiated Plastic Tubing and Wire Insulation

    DEFF Research Database (Denmark)

    Miller, Arne; McLaughlin, W. L.

    1979-01-01

    Plastic tubing and wire insulation were simulated by radiochromic dye dosimeter films having electron absorbing properties similar to the materials of interest (polyethylene and PVC). A 400-keV electron accelerator was used to irradiate from 1, 2, 3 and 4 sides simulating possible industrial...

  9. Electrical insulation and conduction coating for fusion experimental devices

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, Masanori; Tsujimura, Seiji; Toyoda, Masahiko; Inoue, Masahiko [Mitsubishi Heavy Industries, Ltd., Yokohama (Japan); Abe, Tetsuya; Murakami, Yoshio [Japan Atomic Energy Research Inst., Naka (Japan)

    1996-01-01

    The development of electrical insulation and conduction coating methods that can be applied to large components of fusion experimental devices has been investigated. A thermal spraying method is used to coat the insulation or conduction materials on the structural components because of its applicability for large surfaces. The insulation material chosen was Al{sub 2}O{sub 3}, while Cr{sub 3}C{sub 2}-NiCr and WC-NiCr were chosen as conduction materials. These materials were coated on stainless steel substrates to examine the basic characteristics of the coated layers, such as their adhesive strength to the substrate, thermal shock resistance, electrical resistance, dielectric breakdown voltage, and thermal conductivity. It was found that they have sufficient electrical insulation and conduction properties, respectively. In addition, the sliding tests of the coated layers showed adequate frictional properties. The spraying method was tested on a 100- x 1000-mm surface and found to be applicable for large surfaces of experimental fusion devices. 9 refs., 6 figs., 15 tabs.

  10. Electrical insulation and conduction coating for fusion experimental devices

    International Nuclear Information System (INIS)

    Onozuka, Masanori; Tsujimura, Seiji; Toyoda, Masahiko; Inoue, Masahiko; Abe, Tetsuya; Murakami, Yoshio

    1996-01-01

    The development of electrical insulation and conduction coating methods that can be applied to large components of fusion experimental devices has been investigated. A thermal spraying method is used to coat the insulation or conduction materials on the structural components because of its applicability for large surfaces. The insulation material chosen was Al 2 O 3 , while Cr 3 C 2 -NiCr and WC-NiCr were chosen as conduction materials. These materials were coated on stainless steel substrates to examine the basic characteristics of the coated layers, such as their adhesive strength to the substrate, thermal shock resistance, electrical resistance, dielectric breakdown voltage, and thermal conductivity. It was found that they have sufficient electrical insulation and conduction properties, respectively. In addition, the sliding tests of the coated layers showed adequate frictional properties. The spraying method was tested on a 100- x 1000-mm surface and found to be applicable for large surfaces of experimental fusion devices. 9 refs., 6 figs., 15 tabs

  11. 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...

  12. Insulation and Heat Treatment of Bi-2212 Wire for Wind-and-React Coils

    Energy Technology Data Exchange (ETDEWEB)

    Peter K. F. Hwang

    2007-10-22

    Higher Field Magnets demand higher field materials such as Bi-2212 round superconducting wire. The Bi-2212 wire manufacture process depends on the coil fabrication method and wire insulation material. Considering the wind-and-react method, the coil must unifirmly heated to the melt temperature and uniformly cooled to the solidification temperature. During heat treat cycle for tightly wound coils, the leakage melt from conductor can chemically react with insulation on the conductor and creat short turns in the coils. In this research project, conductor, insulation, and coils are made to systemically study the suitable insulation materials, coil fabrication method, and heat treatment cycles. In this phase I study, 800 meters Bi-2212 wire with 3 different insulation materials have been produced. Best insulation material has been identified after testing six small coils for insulation integrity and critical current at 4.2 K. Four larger coils (2" dia) have been also made with Bi-2212 wrapped with best insulation and with different heattreatment cycle. These coils were tested for Ic in a 6T background field and at 4.2 K. The test result shows that Ic from 4 coils are very close to short samples (1 meter) result. It demonstrates that HTS coils can be made with Bi-2212 wire with best insulation consistently. Better wire insulation, improving coil winding technique, and wire manufacture process can be used for a wide range of high field magnet application including acclerators such as Muon Collider, fusion energy research, NMR spectroscopy, MRI, and other industrial magnets.

  13. Insulation and Heat Treatment of Bi-2212 Wires for Wind-and-React Coils

    International Nuclear Information System (INIS)

    Hwang, Peter K.F.

    2007-01-01

    Higher Field Magnets demand higher field materials such as Bi-2212 round superconducting wire. The Bi-2212 wire manufacture process depends on the coil fabrication method and wire insulation material. Considering the wind-and-react method, the coil must unifirmly heated to the melt temperature and uniformly cooled to the solidification temperature. During heat treat cycle for tightly wound coils, the leakage melt from conductor can chemically react with insulation on the conductor and creat short turns in the coils. In this research project, conductor, insulation, and coils are made to systemically study the suitable insulation materials, coil fabrication method, and heat treatment cycles. In this phase I study, 800 meters Bi-2212 wire with 3 different insulation materials have been produced. Best insulation material has been identified after testing six small coils for insulation integrity and critical current at 4.2 K. Four larger coils (2-inch dia) have been also made with Bi-2212 wrapped with best insulation and with different heattreatment cycle. These coils were tested for Ic in a 6T background field and at 4.2 K. The test result shows that Ic from 4 coils are very close to short samples (1 meter) result. It demonstrates that HTS coils can be made with Bi-2212 wire with best insulation consistently. Better wire insulation, improving coil winding technique, and wire manufacture process can be used for a wide range of high field magnet application including acclerators such as Muon Collider, fusion energy research, NMR spectroscopy, MRI, and other industrial magnets.

  14. 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.

  15. 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

  16. Asymmetric Cherenkov acoustic reverse in topological insulators

    Science.gov (United States)

    Smirnov, Sergey

    2014-09-01

    A general phenomenon of the Cherenkov radiation known in optics or acoustics of conventional materials is a formation of a forward cone of, respectively, photons or phonons emitted by a particle accelerated above the speed of light or sound in those materials. Here we suggest three-dimensional topological insulators as a unique platform to fundamentally explore and practically exploit the acoustic aspect of the Cherenkov effect. We demonstrate that by applying an in-plane magnetic field to a surface of a three-dimensional topological insulator one may suppress the forward Cherenkov sound up to zero at a critical magnetic field. Above the critical field the Cherenkov sound acquires pure backward nature with the polar distribution differing from the forward one generated below the critical field. Potential applications of this asymmetric Cherenkov reverse are in the design of low energy electronic devices such as acoustic ratchets or, in general, in low power design of electronic circuits with a magnetic field control of the direction and magnitude of the Cherenkov dissipation.

  17. The overall heat transfer of greenhouses covered with PE [polyethylene film] and PVC [polyvinyl chloride film] single layer: The heat insulation efficiency of greenhouses and their covering materials (1)

    International Nuclear Information System (INIS)

    Minagawa, H.; Tachibana, K.

    1982-01-01

    Overall heat transfer of polyethylene film (PE) and polyvinyl chloride film (PVC) were measured in the experimental greenhouses with hot-air heaters on the clear and on the cloudy nights during the period Nov. 1979 to Jan. 1980. Both films are 0.1 mm thick and have different physical properties for long-wave radiation. The heat insulation efficiency of the greenhouses covered with PE and PVC single layer was investigated, and the ratio of floor area to covering area for the experimental greenhouses, which is one of the indices for the heat insulation efficiency of greenhouses, was also taken into consideration. The results are as follows: 1. Using the ratio of the overall heat transfer and the overall heat transfer coefficients for the heat insulation efficiency, the PE-house revealed to be less efficient than the PVC-house. This can be due to PE being more transparent to long-wave radiation than PVC. The advantage in the PVC-house, however, decreased with the increasing of the inside-outside air temperature difference (Figs. 3 and 5). 2. The overall heat transfer coefficients of both greenhouses depended on the inside-outside temperature difference. As the temperature difference increased, the overall heat transfer coefficients decreased (Fig. 5). 3. The overall heat transfer coefficients of both greenhouses were smaller on the cloudy nights than that on the clear nights. When the condensation occurred at the interior film surface, the heat insulation efficiency of both greenhouses was increased, resulting in the decrease of the coefficient. The efficiency of the PE-house was more affected than the PVC-house when the condensation occurred (Figs. 6 and 7). 4. When the inside-outside air temperature difference was small, convective heat transferred from the outside air to the outside cover surface. With an increase in the inside-outside air temperature difference, convective heat flow occurred from the outside cover surface to the outside air. This phenomenon was

  18. Floquet topological insulators for sound

    Science.gov (United States)

    Fleury, Romain; Khanikaev, Alexander B.; Alù, Andrea

    2016-06-01

    The unique conduction properties of condensed matter systems with topological order have recently inspired a quest for the similar effects in classical wave phenomena. Acoustic topological insulators, in particular, hold the promise to revolutionize our ability to control sound, allowing for large isolation in the bulk and broadband one-way transport along their edges, with topological immunity against structural defects and disorder. So far, these fascinating properties have been obtained relying on moving media, which may introduce noise and absorption losses, hindering the practical potential of topological acoustics. Here we overcome these limitations by modulating in time the acoustic properties of a lattice of resonators, introducing the concept of acoustic Floquet topological insulators. We show that acoustic waves provide a fertile ground to apply the anomalous physics of Floquet topological insulators, and demonstrate their relevance for a wide range of acoustic applications, including broadband acoustic isolation and topologically protected, nonreciprocal acoustic emitters.

  19. Fermi surfaces in Kondo insulators

    Science.gov (United States)

    Liu, Hsu; Hartstein, Máté; Wallace, Gregory J.; Davies, Alexander J.; Ciomaga Hatnean, Monica; Johannes, Michelle D.; Shitsevalova, Natalya; Balakrishnan, Geetha; Sebastian, Suchitra E.

    2018-04-01

    We report magnetic quantum oscillations measured using torque magnetisation in the Kondo insulator YbB12 and discuss the potential origin of the underlying Fermi surface. Observed quantum oscillations as well as complementary quantities such as a finite linear specific heat capacity in YbB12 exhibit similarities with the Kondo insulator SmB6, yet also crucial differences. Small heavy Fermi sections are observed in YbB12 with similarities to the neighbouring heavy fermion semimetallic Fermi surface, in contrast to large light Fermi surface sections in SmB6 which are more similar to the conduction electron Fermi surface. A rich spectrum of theoretical models is suggested to explain the origin across different Kondo insulating families of a bulk Fermi surface potentially from novel itinerant quasiparticles that couple to magnetic fields, yet do not couple to weak DC electric fields.

  20. Topological insulators and topological superconductors

    CERN Document Server

    Bernevig, Andrei B

    2013-01-01

    This graduate-level textbook is the first pedagogical synthesis of the field of topological insulators and superconductors, one of the most exciting areas of research in condensed matter physics. Presenting the latest developments, while providing all the calculations necessary for a self-contained and complete description of the discipline, it is ideal for graduate students and researchers preparing to work in this area, and it will be an essential reference both within and outside the classroom. The book begins with simple concepts such as Berry phases, Dirac fermions, Hall conductance and its link to topology, and the Hofstadter problem of lattice electrons in a magnetic field. It moves on to explain topological phases of matter such as Chern insulators, two- and three-dimensional topological insulators, and Majorana p-wave wires. Additionally, the book covers zero modes on vortices in topological superconductors, time-reversal topological superconductors, and topological responses/field theory and topolo...

  1. Progress of Space Charge Research on Oil-Paper Insulation Using Pulsed Electroacoustic Techniques

    Directory of Open Access Journals (Sweden)

    Chao Tang

    2016-01-01

    Full Text Available This paper focuses on the space charge behavior in oil-paper insulation systems used in power transformers. It begins with the importance of understanding the space charge behavior in oil-paper insulation systems, followed by the introduction of the pulsed electrostatic technique (PEA. After that, the research progress on the space charge behavior of oil-paper insulation during the recent twenty years is critically reviewed. Some important aspects such as the environmental conditions and the acoustic wave recovery need to be addressed to acquire more accurate space charge measurement results. Some breakthroughs on the space charge behavior of oil-paper insulation materials by the research team at the University of Southampton are presented. Finally, future work on space charge measurement of oil-paper insulation materials is proposed.

  2. Eco-balance of a vacuum insulation panel (VIP); Oekobilanz eines Vakuum-Isolations-Paneels (VIP)

    Energy Technology Data Exchange (ETDEWEB)

    Schonhardt, U.; Binz, A.; Wohler, M.; Dott, R. [Institut fuer Energie - Fachhochschule beider Basel, Muttenz (Switzerland); Frischknecht, R. [ESU-services, Uster (Switzerland)

    2003-07-01

    This report for the Swiss Federal Office of Energy (SFOE) made by the Institute for Energy at the University of Applied Sciences in Muttenz and ESU Services in Uster, Switzerland, presents the results of an eco-balance made on the ecological impact of vacuum insulation panels. These panels are being used more and more instead of bulky, traditional insulation materials. The three eco-balance models used - Eco-Indicator 99, Ecological Scarcity UBP 97 and Cumulative Energy Use KEA - are introduced. Comparisons were made between vacuum insulation systems and glass-fibre and polystyrene insulation materials. The methods used are described and the results of the eco-balance analyses made are presented for the three types of insulation. In an appendix to the report, the influence of power generation methods and transport services on the eco-balance is discussed.

  3. Energy savings due to building insulation of different thickness

    Directory of Open Access Journals (Sweden)

    Orzechowski Tadeusz

    2017-01-01

    Full Text Available In the plans of thermo-modernisation of historic buildings, strict requirements on energy performance are often relaxed. Detailed analyses are performed to select thermal upgrading technology that would ensure maximum environmental benefits while preserving the historic value of the building. The analysis of the costs of thermal upgrading with the use of heat-preserving plasters having different insulation properties is made for a coal-fired boiler plant. Optimal and advantageous ranges of insulation materials application are shown in reference to coal savings in boilers with variable and constant efficiency. Climatic conditions and environmental benefits are indicated.

  4. Conductance fluctuations in a macroscopic 3-dimensional Anderson insulator

    International Nuclear Information System (INIS)

    Sanquer, M.

    1990-01-01

    We report magnetoconductance experiment on a amorphous Y x -Si 1-x alloy (∼0.3). which is an Anderson insulator where spin-orbit scattering is strong. Two principal and new features emerge from the data: the first one is an halving of the localization length by the application of a magnetic field of about 2.5 Teslas. This effect is predicted by a new approach of transport in Anderson insulators where basic symetry considerations are the most important ingredient. The second one is the observation of reproducible conductance fluctuations at very low temperature in this macroscopic 3 D amorphous material

  5. Multiple-Nozzle Spray Head Applies Foam Insulation

    Science.gov (United States)

    Walls, Joe T.

    1993-01-01

    Spray head equipped with four-nozzle turret mixes two reactive components of polyurethane and polyisocyanurate foam insulating material and sprays reacting mixture onto surface to be insulated. If nozzle in use becomes clogged, fresh one automatically rotated into position, with minimal interruption of spraying process. Incorporates features recirculating and controlling pressures of reactive components to maintain quality of foam by ensuring proper blend at outset. Also used to spray protective coats on or in ships, aircraft, and pipelines. Sprays such reactive adhesives as epoxy/polyurethane mixtures. Components of spray contain solid-particle fillers for strength, fire retardance, toughness, resistance to abrasion, or radar absorption.

  6. Aerogel / Polymer Composite Materials

    Science.gov (United States)

    Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Roberson, Luke B. (Inventor); Clayton, LaNetra M. (Inventor)

    2017-01-01

    The invention provides new composite materials containing aerogels blended with thermoplastic polymer materials at a weight ratio of aerogel to thermoplastic polymer of less than 20:100. The composite materials have improved thermal insulation ability. The composite materials also have better flexibility and less brittleness at low temperatures than the parent thermoplastic polymer materials.

  7. Materialism.

    Science.gov (United States)

    Melnyk, Andrew

    2012-05-01

    Materialism is nearly universally assumed by cognitive scientists. Intuitively, materialism says that a person's mental states are nothing over and above his or her material states, while dualism denies this. Philosophers have introduced concepts (e.g., realization and supervenience) to assist in formulating the theses of materialism and dualism with more precision, and distinguished among importantly different versions of each view (e.g., eliminative materialism, substance dualism, and emergentism). They have also clarified the logic of arguments that use empirical findings to support materialism. Finally, they have devised various objections to materialism, objections that therefore serve also as arguments for dualism. These objections typically center around two features of mental states that materialism has had trouble in accommodating. The first feature is intentionality, the property of representing, or being about, objects, properties, and states of affairs external to the mental states. The second feature is phenomenal consciousness, the property possessed by many mental states of there being something it is like for the subject of the mental state to be in that mental state. WIREs Cogn Sci 2012, 3:281-292. doi: 10.1002/wcs.1174 For further resources related to this article, please visit the WIREs website. Copyright © 2012 John Wiley & Sons, Ltd.

  8. Electric fields and electrical insulation

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson

    2002-01-01

    The adoption of a field-theoretical approach to problems arising in the framework of electrical insulation is discussed with reference to six main topics, which have been addressed over the last 30 years. These include uniform field electrodes, Green's differential equation, electrode surface...... roughness, induced charge, electrostatic probes, and partial discharge transients, together with several follow-on aspects. Each topic is introduced and thereafter the progress achieved through the use of a field-theoretical approach is reviewed. Because the topics cover a wide spectrum of conditions......, it is amply demonstrated that such an approach can lead to significant progress in many areas of electrical insulation....

  9. Influence of copper on the by-products of different oil-paper insulations

    International Nuclear Information System (INIS)

    Hao Jian; Liao Ruijin; Chen, George; Ma Chao

    2011-01-01

    Transformer failure caused by the corrosion of copper material in transformer attracts great attention of researchers and engineers. In this paper, Karamay No. 25 naphthenic mineral oil, Karamay No. 25 paraffinic mineral oil, Kraft paper and copper were used to compose four combinations of oil-paper insulation samples. The ageing by-products and dielectric properties of the four combinations of oil-paper insulation samples were compared after they were thermally aged at 130 deg. C. The influence of copper on the by-products and dielectric properties of different oil-paper insulations was obtained. The results show that copper can accelerate the ageing rate of insulation oils and reduce their AC breakdown voltage. The content of copper substance dissolved in insulating oil increases with ageing time at first and then decreases. The paper aged in the oil-paper insulation sample with copper has higher moisture content than the one without copper. Results of energy dispersive spectroscopy (EDS) in the scanning electron microscope (SEM) show that there is copper product deposited on the surface of insulation paper. The insulation oil and paper aged in the oil-paper insulation sample with copper have higher dielectric loss and conductivity than that without copper.

  10. Influence of copper on the by-products of different oil-paper insulations

    Energy Technology Data Exchange (ETDEWEB)

    Hao Jian; Liao Ruijin [State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University (China); Chen, George [School of Electronics and Computer Science, University of Southampton (United Kingdom); Ma Chao, E-mail: cquhaojian@126.com [Gansu Electric Power Research Institute (China)

    2011-08-12

    Transformer failure caused by the corrosion of copper material in transformer attracts great attention of researchers and engineers. In this paper, Karamay No. 25 naphthenic mineral oil, Karamay No. 25 paraffinic mineral oil, Kraft paper and copper were used to compose four combinations of oil-paper insulation samples. The ageing by-products and dielectric properties of the four combinations of oil-paper insulation samples were compared after they were thermally aged at 130 deg. C. The influence of copper on the by-products and dielectric properties of different oil-paper insulations was obtained. The results show that copper can accelerate the ageing rate of insulation oils and reduce their AC breakdown voltage. The content of copper substance dissolved in insulating oil increases with ageing time at first and then decreases. The paper aged in the oil-paper insulation sample with copper has higher moisture content than the one without copper. Results of energy dispersive spectroscopy (EDS) in the scanning electron microscope (SEM) show that there is copper product deposited on the surface of insulation paper. The insulation oil and paper aged in the oil-paper insulation sample with copper have higher dielectric loss and conductivity than that without copper.

  11. A decking for erecting an insulating connector

    Energy Technology Data Exchange (ETDEWEB)

    Chuprikov, A Ye; Lagutin, V I; Sklyarov, A A; Sukhanov, G V

    1983-01-01

    The decking includes a parachute like dome, made of a material impenetrable to air, an air penetrable hood, attachment elements and a branch pipe for supplying the filler. To improve the sealing of the insulating connector upon contact with the walls and the roof of the drift being isolated and to reduce the labor intensity of operations, it is equipped with a housing made in the form of a cylinder from a material impenetrable to water, an advancible vertical upright and a spring loaded panel. The housing is installed between the parachute like dome and the air penetrable hood. The extendible vertical upright is installed on the side of the air penetrable hood and by means of a movable rack mechanism is kinematically linked with the spring loaded panel, installed with the capability of interacting with the air penetrable hood. The spring loaded plate is made in the form of perforated plates which have a telescopic disengagement in the horizontal plane.

  12. CFC alternatives for thermal insulation foams

    Energy Technology Data Exchange (ETDEWEB)

    Shankland, I.R. (Allied-Signal Inc., Buffalo, NY (US))

    1990-03-01

    Low density polymeric foam materials expanded with chlorofluorocarbon (CFC) blowing agents have found widespread use as highly efficient thermal insulation materials in the construction, refrigeration appliance and transportation industries. The advent of regulations which are reducing the production and consumption of the fully halogenated CFCs for environmental reasons has prompted the development of environmentally acceptable substitutes for the CFC blowing agents. This paper summarizes the physical properties and performance of the leading alternatives for CFC-11, which is used to expand rigid polyurethane and polyisocyanurate foams, and the leading alternatives for CFC-12 which is used to expand extruded polystyrene board foam. Although the alternatives, HCFC-123 and HCFC-14lb for CFC-11 and HCFC142b and HCFC-124 for CFC-12, are not perfect matches from the performance viewpoint, they represent the optimum choice given the constraints on environmental acceptability, toxicity, flammability and performance. (author).

  13. Development of a Diehard GEM using PTFE insulator substrate

    International Nuclear Information System (INIS)

    Wakabayashi, M; Tamagawa, T; Takeuchi, Y; Aoki, K; Taketani, A; Komiya, K; Hamagaki, H

    2014-01-01

    We have developed the gas electron multiplier (GEM) using polytetrafluoroethylene (PTFE) insulator substrate (PTFE-GEM). Carbonization on insulator layer by discharges shorts the GEM electrodes, causing permanent breakdown. Since PTFE is hard to be carbonized against arc discharges, PTFE-GEM is expected to be robust against breakdown. Gains as high as 2.6 × 10 4 were achieved with PTFE-GEM (50 μm thick) in Ar/CO 2 = 70%/30% gas mixture at V GEM = 730 V. PTFE-GEM never showed a permanent breakdown even after suffering more than 40000 times discharges during the experiment. The result demonstrates that PTFE-GEM is really robust against discharges. We conclude that PTFE is an excellent insulator material for the GEM productions

  14. Inducing magneto-electric response in topological insulator

    International Nuclear Information System (INIS)

    Zeng, Lunwu; Song, Runxia; Zeng, Jing

    2013-01-01

    Utilizing electric potential and magnetic scalar potential formulas, which contain zero-order Bessel functions of the first kind and the constitutive relations of topological insulators, we obtained the induced magnetic scalar potentials and induced magnetic monopole charges which are induced by a point charge in topological insulators. The results show that infinite image magnetic monopole charges are generated by a point electric charge. The magnitude of the induced magnetic monopole charges are determined not only by the point electric charge, but also by the material parameters. - Highlights: ► Electric potential and magnetic scalar potential which contain zero-order Bessel function of the first kind were derived. ► Boundary conditions of topological insulator were built. ► Induced monopole charges were worked out.

  15. Nanoscale electron transport at the surface of a topological insulator

    Science.gov (United States)

    Bauer, Sebastian; Bobisch, Christian A.

    2016-04-01

    The use of three-dimensional topological insulators for disruptive technologies critically depends on the dissipationless transport of electrons at the surface, because of the suppression of backscattering at defects. However, in real devices, defects are unavoidable and scattering at angles other than 180° is allowed for such materials. Until now, this has been studied indirectly by bulk measurements and by the analysis of the local density of states in close vicinity to defect sites. Here, we directly measure the nanoscale voltage drop caused by the scattering at step edges, which occurs if a lateral current flows along a three-dimensional topological insulator. The experiments were performed using scanning tunnelling potentiometry for thin Bi2Se3 films. So far, the observed voltage drops are small because of large contributions of the bulk to the electronic transport. However, for the use of ideal topological insulating thin films in devices, these contributions would play a significant role.

  16. 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)

  17. Inducing magneto-electric response in topological insulator

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Lunwu, E-mail: 163.sin@163.com [Jiangsu Key Laboratory for Intelligent Agricultural Equipment, College of Engineering, Nanjing Agricultural University, Nanjing 210031 (China); Song, Runxia [Jiangsu Key Laboratory for Intelligent Agricultural Equipment, College of Engineering, Nanjing Agricultural University, Nanjing 210031 (China); Zeng, Jing [Faculty of Business and Economics, Macquarie University, NSW 2122 (Australia)

    2013-02-15

    Utilizing electric potential and magnetic scalar potential formulas, which contain zero-order Bessel functions of the first kind and the constitutive relations of topological insulators, we obtained the induced magnetic scalar potentials and induced magnetic monopole charges which are induced by a point charge in topological insulators. The results show that infinite image magnetic monopole charges are generated by a point electric charge. The magnitude of the induced magnetic monopole charges are determined not only by the point electric charge, but also by the material parameters. - Highlights: Black-Right-Pointing-Pointer Electric potential and magnetic scalar potential which contain zero-order Bessel function of the first kind were derived. Black-Right-Pointing-Pointer Boundary conditions of topological insulator were built. Black-Right-Pointing-Pointer Induced monopole charges were worked out.

  18. 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.

  19. Wide gap Chern Mott insulating phases achieved by design

    Science.gov (United States)

    Guo, Hongli; Gangopadhyay, Shruba; Köksal, Okan; Pentcheva, Rossitza; Pickett, Warren E.

    2017-12-01

    Quantum anomalous Hall insulators, which display robust boundary charge and spin currents categorized in terms of a bulk topological invariant known as the Chern number (Thouless et al Phys. Rev. Lett. 49, 405-408 (1982)), provide the quantum Hall anomalous effect without an applied magnetic field. Chern insulators are attracting interest both as a novel electronic phase and for their novel and potentially useful boundary charge and spin currents. Honeycomb lattice systems such as we discuss here, occupied by heavy transition-metal ions, have been proposed as Chern insulators, but finding a concrete example has been challenging due to an assortment of broken symmetry phases that thwart the topological character. Building on accumulated knowledge of the behavior of the 3d series, we tune spin-orbit and interaction strength together with strain to design two Chern insulator systems with bandgaps up to 130 meV and Chern numbers C = -1 and C = 2. We find, in this class, that a trade-off between larger spin-orbit coupling and strong interactions leads to a larger gap, whereas the stronger spin-orbit coupling correlates with the larger magnitude of the Hall conductivity. Symmetry lowering in the course of structural relaxation hampers obtaining quantum anomalous Hall character, as pointed out previously; there is only mild structural symmetry breaking of the bilayer in these robust Chern phases. Recent growth of insulating, magnetic phases in closely related materials with this orientation supports the likelihood that synthesis and exploitation will follow.

  20. Optimization of Refining Craft for Vegetable Insulating Oil

    Science.gov (United States)

    Zhou, Zhu-Jun; Hu, Ting; Cheng, Lin; Tian, Kai; Wang, Xuan; Yang, Jun; Kong, Hai-Yang; Fang, Fu-Xin; Qian, Hang; Fu, Guang-Pan

    2016-05-01

    Vegetable insulating oil because of its environmental friendliness are considered as ideal material instead of mineral oil used for the insulation and the cooling of the transformer. The main steps of traditional refining process included alkali refining, bleaching and distillation. This kind of refining process used in small doses of insulating oil refining can get satisfactory effect, but can't be applied to the large capacity reaction kettle. This paper using rapeseed oil as crude oil, and the refining process has been optimized for large capacity reaction kettle. The optimized refining process increases the acid degumming process. The alkali compound adds the sodium silicate composition in the alkali refining process, and the ratio of each component is optimized. Add the amount of activated clay and activated carbon according to 10:1 proportion in the de-colorization process, which can effectively reduce the oil acid value and dielectric loss. Using vacuum pumping gas instead of distillation process can further reduce the acid value. Compared some part of the performance parameters of refined oil products with mineral insulating oil, the dielectric loss of vegetable insulating oil is still high and some measures are needed to take to further optimize in the future.