Mechanism of the free charge carrier generation in the dielectric breakdown

NASA Astrophysics Data System (ADS)

Rahim, N. A. A.; Ranom, R.; Zainuddin, H.

2017-12-01

Many studies have been conducted to investigate the effect of environmental, mechanical and electrical stresses on insulator. However, studies on physical process of discharge phenomenon, leading to the breakdown of the insulator surface are lacking and difficult to comprehend. Therefore, this paper analysed charge carrier generation mechanism that can cause free charge carrier generation, leading toward surface discharge development. Besides, this paper developed a model of surface discharge based on the charge generation mechanism on the outdoor insulator. Nernst’s Planck theory was used in order to model the behaviour of the charge carriers while Poisson’s equation was used to determine the distribution of electric field on insulator surface. In the modelling of surface discharge on the outdoor insulator, electric field dependent molecular ionization was used as the charge generation mechanism. A mathematical model of the surface discharge was solved using method of line technique (MOL). The result from the mathematical model showed that the behaviour of net space charge density was correlated with the electric field distribution.

The range of thermal insulation in the tissues of the new-born baby

PubMed Central

Hey, E. N.; Katz, G.

1970-01-01

1. Rectal temperature and skin temperatures were measured in twenty-eight naked babies weighing 1·1-4·5 kg, lying supine in environments of 25-31 °C when air speed was 4-7 cm/sec. The ratio of external insulation to internal or tissue insulation for the whole body averaged 2·7 but varied inversely with body weight; the ratio was higher than this on the trunk, and five times lower than this on the hand and foot. The mean ratio rose threefold when environmental temperature was increased to 34-35° C. 2. Direct measurements of heat flow from the back of a hand placed in a water jacket maintained at 32° C were made in thirty-three babies. Heat loss averaged 3 kcal/m2.hr.° C at low environmental temperature, but the loss was often rather less than this in the first 24 hr of life. Heat loss from the hand increased three- to fourfold, during exposure to an environment of 35° C. 3. When babies more than 48 hr old were exposed to an environment of 34-35° C, heat loss from the hand only increased when rectal temperature reached between 36·6 and 37·3° C; a slightly higher rectal temperature was usually reached before heat loss rose in babies less than 24 hr old. 4. Similar methods were used to study specific tissue insulation in three babies with congenital defects of the brain who lacked evidence of temperature control. No changes in insulation were detected in these three babies following changes in environmental temperature. 5. It is concluded that the range and pattern of control that can be exerted over the specific thermal insulation of the tissues is essentially the same in babies 2-20 days old as it is in adult life. PMID:5499741

Three insulation methods to minimize intravenous fluid administration set heat loss.

PubMed

Piek, Richardt; Stein, Christopher

2013-01-01

To assess the effect of three methods for insulating an intravenous (IV) fluid administration set on the temperature of warmed fluid delivered rapidly in a cold environment. The three chosen techniques for insulation of the IV fluid administration set involved enclosing the tubing of the set in 1) a cotton conforming bandage, 2) a reflective emergency blanket, and 3) a combination of technique 2 followed by technique 1. Intravenous fluid warmed to 44°C was infused through a 20-drop/mL 180-cm-long fluid administration set in a controlled environmental temperature of 5°C. Temperatures in the IV fluid bag, the distal end of the fluid administration set, and the environment were continuously measured with resistance thermosensors. Twenty repetitions were performed in four conditions, namely, a control condition (with no insulation) and the three different insulation methods described above. One-way analysis of variance was used to assess the mean difference in temperature between the IV fluid bag and the distal fluid administration set under the four conditions. In the control condition, a mean of 5.28°C was lost between the IV fluid bag and the distal end of the fluid administration set. There was a significant difference found between the four conditions (p < 0.001). A mean of 3.53°C was lost between the IV fluid bag and the distal end of the fluid administration set for both the bandage and reflective emergency blanket, and a mean of 3.06°C was lost when the two methods were combined. Using inexpensive and readily available materials to insulate a fluid administration set can result in a reduction of heat loss in rapidly infused, warmed IV fluid in a cold environment.

Assessment of the risk of failure of high voltage substations due to environmental conditions and pollution on insulators.

PubMed

Castillo Sierra, Rafael; Oviedo-Trespalacios, Oscar; Candelo, John E; Soto, Jose D

2015-07-01

Pollution on electrical insulators is one of the greatest causes of failure of substations subjected to high levels of salinity and environmental pollution. Considering leakage current as the main indicator of pollution on insulators, this paper focuses on establishing the effect of the environmental conditions on the risk of failure due to pollution on insulators and determining the significant change in the magnitude of the pollution on the insulators during dry and humid periods. Hierarchical segmentation analysis was used to establish the effect of environmental conditions on the risk of failure due to pollution on insulators. The Kruskal-Wallis test was utilized to determine the significant changes in the magnitude of the pollution due to climate periods. An important result was the discovery that leakage current was more common on insulators during dry periods than humid ones. There was also a higher risk of failure due to pollution during dry periods. During the humid period, various temperatures and wind directions produced a small change in the risk of failure. As a technical result, operators of electrical substations can now identify the cause of an increase in risk of failure due to pollution in the area. The research provides a contribution towards the behaviour of the leakage current under conditions similar to those of the Colombian Caribbean coast and how they affect the risk of failure of the substation due to pollution.

Environmental and Sustainable Technology Evaluation: Mold-Resistant Armacell Insulation--Armacell LLC, AP Armaflex Black

EPA Science Inventory

The ESTE test program measured the mold resistance of Armacell AP Armaflex Black insulation. Tests for emissions of VOCs and formaldehyde were also performed. AP Armaflex Roll Insulation is a black flexible closed-cell, fiber-free elastomeric thermal insulation. The expanded clos...

BULK SAMPLE ANALYSIS FOR ASBESTOS CONTENT: EVALUATION OF THE TENTATIVE METHOD

EPA Science Inventory

The U.S. Environmental Protection Agency Asbestos-in-Schools Program was established in March, 1979 to provide information and technical assistance to the public for addressing problems presented by asbestos-containing insulation materials in school buildings. Because there were ...

Implementation of environmentally compliant cleaning and insulation bonding for MNASA

NASA Technical Reports Server (NTRS)

Hutchens, Dale E.; Keen, Jill M.; Smith, Gary M.; Dillard, Terry W.; Deweese, C. Darrell; Lawson, Seth W.

1995-01-01

Historically, many subscale and full-scale rocket motors have employed environmentally and physiologically harmful chemicals during the manufacturing process. This program examines the synergy and interdependency between environmentally acceptable materials for solid rocket motor insulation applications, bonding, corrosion inhibiting, painting, priming, and cleaning, and then implements new materials and processes in subscale motors. Tests have been conducted to eliminate or minimize hazardous chemicals used in the manufacture of modified-NASA materials test motor (MNASA) components and identify alternate materials and/or processes following NASA Operational Environmental Team (NOET) priorities. This presentation describes implementation of high pressure water refurbishment cleaning, aqueous precision cleaning using both Brulin 815 GD and Jettacin, and insulation case bonding using ozone depleting chemical (ODC) compliant primers and adhesives.

Electrical condition monitoring method for polymers

DOEpatents

Watkins, Jr. Kenneth S.; Morris, Shelby J.; Masakowski, Daniel D.; Wong, Ching Ping; Luo, Shijian

2010-02-16

An electrical condition monitoring method utilizes measurement of electrical resistivity of a conductive composite degradation sensor to monitor environmentally induced degradation of a polymeric product such as insulated wire and cable. The degradation sensor comprises a polymeric matrix and conductive filler. The polymeric matrix may be a polymer used in the product, or it may be a polymer with degradation properties similar to that of a polymer used in the product. The method comprises a means for communicating the resistivity to a measuring instrument and a means to correlate resistivity of the degradation sensor with environmentally induced degradation of the product.

Heat insulation performance, mechanics and hydrophobic modification of cellulose-SiO2 composite aerogels.

PubMed

Shi, Jianjun; Lu, Lingbin; Guo, Wantao; Zhang, Jingying; Cao, Yang

2013-10-15

Cellulose-SiO2 composite hydrogel was prepared by combining the NaOH/thiourea/H2O solvent system and the immersion method with controlling the hydrolysis-fasculation rate of tetraethyl orthosilicate (TEOS). The hydrophobic composite aerogels were obtained through the freeze-drying technology and the cold plasma modification technology. Composite SiO2 could obviously reduce the thermal conductivity of cellulose aerogel. The thermal conductivity could be as low as 0.026 W/(mK). The thermal insulation mechanism of the aerogel material was discussed. Composite SiO2 reduced hydrophilicity of cellulose aerogel, but environmental humidity had a significant influence on heat insulation performance. After hydrophobic modification using CCl4 as plasma was conducted, the surface of composite aerogel was changed from hydrophilic to hydrophobic and water contact angle was as high as 132°. The modified composite aerogel still kept good heat insulation performance. This work provided a foundation for the possibility of applying cellulose-SiO2 composite aerogel in the insulating material field. Copyright © 2013 Elsevier Ltd. All rights reserved.

Prediction of clothing thermal insulation and moisture vapour resistance of the clothed body walking in wind.

PubMed

Qian, Xiaoming; Fan, Jintu

2006-11-01

Clothing thermal insulation and moisture vapour resistance are the two most important parameters in thermal environmental engineering, functional clothing design and end use of clothing ensembles. In this study, clothing thermal insulation and moisture vapour resistance of various types of clothing ensembles were measured using the walking-able sweating manikin, Walter, under various environmental conditions and walking speeds. Based on an extensive experimental investigation and an improved understanding of the effects of body activities and environmental conditions, a simple but effective direct regression model has been established, for predicting the clothing thermal insulation and moisture vapour resistance under wind and walking motion, from those when the manikin was standing in still air. The model has been validated by using experimental data reported in the previous literature. It has shown that the new models have advantages and provide very accurate prediction.

High thermal conductivity lossy dielectric using co-densified multilayer configuration

DOEpatents

Tiegs, Terry N.; Kiggans, Jr., James O.

2003-06-17

Systems and methods are described for loss dielectrics. A method of manufacturing a lossy dielectric includes providing at least one high dielectric loss layer and providing at least one high thermal conductivity-electrically insulating layer adjacent the at least one high dielectric loss layer and then densifying together. The systems and methods provide advantages because the lossy dielectrics are less costly and more environmentally friendly than the available alternatives.

Development of lifetime test procedure for powder evacuated panel insulation. CRADA final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilkes, K E; Graves, R S; Childs, K W

This CRADA is between Appliance Research Consortium (ARC) of the Association of Home Appliance Manufacturers (AHAM) and the Lockheed Martin Energy Research Corp. A Powder Evacuated Panel (PEP) is a "super" thermal insulation, having a thermal resistivity (R) substantially above that of existing insulation without the environmental problems of some insulations such as Chlorofluorocarbon (CFC) blown foam.

Low-Temperature Fabrication of Robust, Transparent, and Flexible Thin-Film Transistors with a Nanolaminated Insulator.

PubMed

Kwon, Jeong Hyun; Park, Junhong; Lee, Myung Keun; Park, Jeong Woo; Jeon, Yongmin; Shin, Jeong Bin; Nam, Minwoo; Kim, Choong-Ki; Choi, Yang-Kyu; Choi, Kyung Cheol

2018-05-09

The lack of reliable, transparent, and flexible electrodes and insulators for applications in thin-film transistors (TFTs) makes it difficult to commercialize transparent, flexible TFTs (TF-TFTs). More specifically, conventional high process temperatures and the brittleness of these elements have been hurdles in developing flexible substrates vulnerable to heat. Here, we propose electrode and insulator fabrication techniques considering process temperature, transmittance, flexibility, and environmental stability. A transparent and flexible indium tin oxide (ITO)/Ag/ITO (IAI) electrode and an Al 2 O 3 /MgO (AM)-laminated insulator were optimized at the low temperature of 70 °C for the fabrication of TF-TFTs on a polyethylene terephthalate (PET) substrate. The optimized IAI electrode with a sheet resistance of 7 Ω/sq exhibited the luminous transmittance of 85.17% and maintained its electrical conductivity after exposure to damp heat conditions because of an environmentally stable ITO capping layer. In addition, the electrical conductivity of IAI was maintained after 10 000 bending cycles with a tensile strain of 3% because of the ductile Ag film. In the metal/insulator/metal structure, the insulating and mechanical properties of the optimized AM-laminated film deposited at 70 °C were significantly improved because of the highly dense nanolaminate system, compared to those of the Al 2 O 3 film deposited at 70 °C. In addition, the amorphous indium-gallium-zinc oxide (a-IGZO) was used as the active channel for TF-TFTs because of its excellent chemical stability. In the environmental stability test, the ITO, a-IGZO, and AM-laminated films showed the excellent environmental stability. Therefore, our IGZO-based TFT with IAI electrodes and the 70 °C AM-laminated insulator was fabricated to evaluate robustness, transparency, flexibility, and process temperature, resulting in transfer characteristics comparable to those of an IGZO-based TFT with a 150 °C Al 2 O 3 insulator.

Applications of thermal infrared imagery for energy conservation and environmental surveys

NASA Technical Reports Server (NTRS)

Carney, J. R.; Vogel, T. C.; Howard, G. E., Jr.; Love, E. R.

1977-01-01

The survey procedures, developed during the winter and summer of 1976, employ color and color infrared aerial photography, thermal infrared imagery, and a handheld infrared imaging device. The resulting imagery was used to detect building heat losses, deteriorated insulation in built-up type building roofs, and defective underground steam lines. The handheld thermal infrared device, used in conjunction with the aerial thermal infrared imagery, provided a method for detecting and locating those roof areas that were underlain with wet insulation. In addition, the handheld infrared device was employed to conduct a survey of a U.S. Army installation's electrical distribution system under full operating loads. This survey proved to be cost effective procedure for detecting faulty electrical insulators and connections that if allowed to persist could have resulted in both safety hazards and loss in production.

Thermographic Methods of Detecting Insulation Voids in Large Cryogenic Tanks

NASA Technical Reports Server (NTRS)

Arens, Ellen; Nurge, Mark; Youngquist, Robert; Starr, Stanley

2010-01-01

Four very large (900Kgal) cryogenic liquid hydrogen and oxygen storage tanks at Kennedy Space Center's LC-39 launch pads were constructed in 1965 to support the Apollo/Saturn V Program and continue to support the Space Shuttle Program. These double-walled spherical tanks with powdered insulation in the annular region, have received minimal refurbishment or even inspection over the years. Intrusively inspecting these tanks would mean a significant down time to the program as the cryogenic liquid and the perlite insulation would have to be removed which would be a significant task and long-term schedule disruption. A study of the tanks was performed to determine the extent to which performance and structural information could be revealed without intrusive inspection. Thermal images of the tanks were taken over a variety of environmental conditions to determine the best conditions under which to compare and use thermography as a health monitoring technique as the tanks continue to age. The settling and subsequent compaction of insulation is a serious concern for cryogenic tanks. Comparison of images from the tanks reveals significant variations in the insulation in the annual regions and point to the use of thermography as a way to monitor for insulation migration and possible compaction. These measurements, when combined with mathematical models of historical boil-off data provide key insight to the condition of the vessels. Acceptance testing methods for new tanks, before they are filled with cryogenic commodity (and thereby thermally cycled), are needed and we explore how thermography can be used to accomplish this.

Multilayer Insulation Material Guidelines

NASA Technical Reports Server (NTRS)

Finckenor, M. M.; Dooling, D.

1999-01-01

Multilayer Insulation Material Guidelines provides data on multilayer insulation materials used by previous spacecraft such as Spacelab and the Long-Duration Exposure Facility and outlines other concerns. The data presented in the document are presented for information only. They can be used as guidelines for multilayer insulation design for future spacecraft provided the thermal requirements of each new design and the environmental effects on these materials are taken into account.

Sprayable Phase Change Coating Thermal Protection Material

NASA Technical Reports Server (NTRS)

Richardson, Rod W.; Hayes, Paul W.; Kaul, Raj

2005-01-01

NASA has expressed a need for reusable, environmentally friendly, phase change coating that is capable of withstanding the heat loads that have historically required an ablative thermal insulation. The Space Shuttle Program currently relies on ablative materials for thermal protection. The problem with an ablative insulation is that, by design, the material ablates away, in fulfilling its function of cooling the underlying substrate, thus preventing the insulation from being reused from flight to flight. The present generation of environmentally friendly, sprayable, ablative thermal insulation (MCC-l); currently use on the Space Shuttle SRBs, is very close to being a reusable insulation system. In actual flight conditions, as confirmed by the post-flight inspections of the SRBs, very little of the material ablates. Multi-flight thermal insulation use has not been qualified for the Space Shuttle. The gap that would have to be overcome in order to implement a reusable Phase Change Coating (PCC) is not unmanageable. PCC could be applied robotically with a spray process utilizing phase change material as filler to yield material of even higher strength and reliability as compared to MCC-1. The PCC filled coatings have also demonstrated potential as cryogenic thermal coatings. In experimental thermal tests, a thin application of PCC has provided the same thermal protection as a much thicker and heavier application of a traditional ablative thermal insulation. In addition, tests have shown that the structural integrity of the coating has been maintained and phase change performance after several aero-thermal cycles was not affected. Experimental tests have also shown that, unlike traditional ablative thermal insulations, PCC would not require an environmental seal coat, which has historically been required to prevent moisture absorption by the thermal insulation, prevent environmental degradation, and to improve the optical and aerodynamic properties. In order to reduce the launch and processing costs of a reusable space vehicle to an affordable level, refurbishment costs must be substantially reduced. A key component of such a cost effective approach is the use of a reusable, phase change, thermal protection coating.

3D quantification of microclimate volume in layered clothing for the prediction of clothing insulation.

PubMed

Lee, Yejin; Hong, Kyunghi; Hong, Sung-Ae

2007-05-01

Garment fit and resultant air volume is a crucial factor in thermal insulation, and yet, it has been difficult to quantify the air volume of clothing microclimate and relate it to the thermal insulation value just using the information on the size of clothing pattern without actual 3D volume measurement in wear condition. As earlier methods for the computation of air volume in clothing microclimate, vacuum over suit and circumference model have been used. However, these methods have inevitable disadvantages in terms of cost or accuracy due to the limitations of measurement equipment. In this paper, the phase-shifting moiré topography was introduced as one of the 3D scanning tools to measure the air volume of clothing microclimate quantitatively. The purpose of this research is to adopt a non-contact image scanning technology, phase-shifting moiré topography, to ascertain relationship between air volume and insulation value of layered clothing systems in wear situations where the 2D fabric creates new conditions in 3D spaces. The insulation of vests over shirts as a layered clothing system was measured with a thermal manikin in the environmental condition of 20 degrees C, 65% RH and air velocity of 0.79 m/s. As the pattern size increased, the insulation of the clothing system was increased. But beyond a certain limit, the insulation started to decrease due to convection and ventilation, which is more apparent when only the vest was worn over the torso of manikin. The relationship between clothing air volume and insulation was difficult to predict with a single vest due to the extreme openings which induced active ventilation. But when the vest was worn over the shirt, the effects of thickness of the fabrics on insulation were less pronounced compared with that of air volume. In conclusion, phase-shifting moiré topography was one of the efficient and accurate ways of quantifying air volume and its distribution across the clothing microclimate. It is also noted that air volume becomes more crucial factor in predicting thermal insulation when clothing is layered.

Washing Off Polyurethane Foam Insulation

NASA Technical Reports Server (NTRS)

Burley, Richard K.; Fogel, Irving

1990-01-01

Jet of hot water removes material quickly and safely. Simple, environmentally sound technique found to remove polyurethane foam insulation from metal parts. Developed for (but not limited to) use during rebuilding of fuel system of Space Shuttle main engine, during which insulation must be removed for penetrant inspection of metal parts.

Theoretical analysis of three methods for calculating thermal insulation of clothing from thermal manikin.

PubMed

Huang, Jianhua

2012-07-01

There are three methods for calculating thermal insulation of clothing measured with a thermal manikin, i.e. the global method, the serial method, and the parallel method. Under the condition of homogeneous clothing insulation, these three methods yield the same insulation values. If the local heat flux is uniform over the manikin body, the global and serial methods provide the same insulation value. In most cases, the serial method gives a higher insulation value than the global method. There is a possibility that the insulation value from the serial method is lower than the value from the global method. The serial method always gives higher insulation value than the parallel method. The insulation value from the parallel method is higher or lower than the value from the global method, depending on the relationship between the heat loss distribution and the surface temperatures. Under the circumstance of uniform surface temperature distribution over the manikin body, the global and parallel methods give the same insulation value. If the constant surface temperature mode is used in the manikin test, the parallel method can be used to calculate the thermal insulation of clothing. If the constant heat flux mode is used in the manikin test, the serial method can be used to calculate the thermal insulation of clothing. The global method should be used for calculating thermal insulation of clothing for all manikin control modes, especially for thermal comfort regulation mode. The global method should be chosen by clothing manufacturers for labelling their products. The serial and parallel methods provide more information with respect to the different parts of clothing.

Recycled-PET fibre based panels for building thermal insulation: environmental impact and improvement potential assessment for a greener production.

PubMed

Ingrao, Carlo; Lo Giudice, Agata; Tricase, Caterina; Rana, Roberto; Mbohwa, Charles; Siracusa, Valentina

2014-09-15

A screening of Life Cycle Assessment for the evaluation of the damage arising from the production of 1 kg of recycled Polyethylene Terephthalate (RPET) fibre-based panel for building heat insulation was carried out according to the ISO 14040:2006 and 14044:2006. All data used were collected on site based on observations during site visits, review of documents and interviews with technical personnel and management. These data were processed by using SimaPro 7.3.3, accessing the Ecoinvent v.2.2 database and using the Impact 2002+ method. The study showed damage to be equal to 0.000299 points mostly due to the: 1) PET thermo-bonding fibre supply from China by means of a freight-equipped intercontinental aircraft; 2) production of bottle-grade granulate PET; 3) medium voltage electricity consumption during the manufacturing of RPET fibre panel. It was also highlighted that there were environmental benefits due to recycling through mainly avoiding significant emissions and reduced resource consumption. An improvement assessment was carried out to find solutions aimed at reducing the damage coming from the most impacting phases. Furthermore, the environmental impacts due to the production of the analysed RPET fibre-based panel were compared to other materials with the same insulating function, such as polystyrene foam, rock wool and cork slab. Finally, the environmental benefits of the recycling of PET bottles for flake production were highlighted compared to other treatment scenarios such as landfill and municipal incineration. Copyright © 2014 Elsevier B.V. All rights reserved.

Environmental durability diagnostic for printed identification codes of polymer insulation for distribution pipelines

NASA Astrophysics Data System (ADS)

Zhuravleva, G. N.; Nagornova, I. V.; Kondratov, A. P.; Bablyuk, E. B.; Varepo, L. G.

2017-08-01

A research and modelling of weatherability and environmental durability of multilayer polymer insulation of both cable and pipelines with printed barcodes or color identification information were performed. It was proved that interlayer printing of identification codes in distribution pipelines insulation coatings provides high marking stability to light and atmospheric condensation. This allows to carry out their distant damage control. However, microbiological fouling of upper polymer layer hampers the distant damage pipelines identification. The color difference values and density changes of PE and PVC printed insolation due to weather and biological factors were defined.

Aging Wire Insulation Assessment by Phase Spectrum Examination of Ultrasonic Guided Waves

NASA Technical Reports Server (NTRS)

Anastasi, Robert F.; Madaras, Eric I.

2003-01-01

Wire integrity has become an area of concern to the aerospace community including DoD, NASA, FAA, and Industry. Over time and changing environmental conditions, wire insulation can become brittle and crack. The cracks expose the wire conductor and can be a source of equipment failure, short circuits, smoke, and fire. The technique of using the ultrasonic phase spectrum to extract material properties of the insulation is being examined. Ultrasonic guided waves will propagate in both the wire conductor and insulation. Assuming the condition of the conductor remains constant then the stiffness of the insulator can be determined by measuring the ultrasonic guided wave velocity. In the phase spectrum method the guided wave velocity is obtained by transforming the time base waveform to the frequency domain and taking the phase difference between two waveforms. The result can then be correlated with a database, derived by numerical model calculations, to extract material properties of the wire insulator. Initial laboratory tests were performed on a simple model consisting of a solid cylinder and then a solid cylinder with a polymer coating. For each sample the flexural mode waveform was identified. That waveform was then transformed to the frequency domain and a phase spectrum was calculated from a pair of waveforms. Experimental results on the simple model compared well to numerical calculations. Further tests were conducted on aircraft or mil-spec wire samples, to see if changes in wire insulation stiffness can be extracted using the phase spectrum technique.

Sceening, down selection, and implementation of environmentally compliant cleaning and insulation bonding for MNASA

NASA Astrophysics Data System (ADS)

Keen, Jill M.; Hutchens, D. E.; Smith, G. M.; Dillard, T. W.

1994-06-01

MNASA, a quarter-scale space shuttle solid rocket motor, has historically been processed using environmentally and physiologically harmful chemicals. This program draws from previous testing done in support of full-scale manufacturing and examines the synergy and interdependency between environmentally acceptable materials for Solid Rocket Motor insulation applications, bonding, corrosion inhibiting, painting, priming and cleaning; and then implements new materials and processes in sub-scale motors. Tests have been conducted to eliminate or minimize hazardous chemicals used in the manufacture of MNASA components and identify alternate materials and/or processes following NASA Operational Environment Team (NOET) priorities. This presentation describes implementation of high pressure water refurbishment cleaning, aqueous precision cleaning using both Brulin 815 GD and Jettacin and insulation case bonding using ODC compliant primers and adhesives.

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

PubMed

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

2018-01-01

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

Thermal insulation of young calves exposed to cold.

PubMed Central

Rawson, R E; Dziuk, H E; Good, A L; Anderson, J F; Bates, D W; Ruth, G R

1989-01-01

Tissue, external and whole animal insulation values were determined for 12 newborn male Holstein calves continuously housed for two weeks in hutches within environmental chambers in which temperature was maintained at a constant 17 degrees C (three calves) or cycled on a daily basis either between -20 degrees and -8 degrees C (three calves) or between -30 degrees and -18 degrees C (six calves). Three of the six calves at the coldest temperature were outfitted with an insulated coat. The insulated coat provided calves a 52% increase in total insulation. Tissue insulation of cold-housed calves increased 37.2% over the first two weeks of life. It was concluded that the capacity for vasoconstriction improved with age. External insulation did not change significantly except during the first week in cold-housed calves without insulated coats. External insulation values were five to eight times those of tissue insulation values for all treatment groups. This indicated that insulation of structures external to the skin (hair, bedding, ground, etc.) provided most of the insulation for calves. PMID:2766147

REPORT OF THE QUALIFICATION TESTING OF SNAP 10A FUSISTORS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holtwick, J.S. III; Nowell, V.P.

1963-07-31

Qualification testing of SNAP 10A fusistors was performed. Test operations included: visual inspection, insulation resistance, dielectric strength, and d-c resistance testing prior to subjecting the fusisters to environmental testing; opening-time testing prior to, during, and following vacuum and temperature testing; and insulation resistance, dielectric strength, and d-c resistance testing following environmental applications of temperature, vacuum, and sinusoidal vibration. (auth)

Ecological Risks in Residential Premises Arising from Thermal Insulation by Pouring

NASA Astrophysics Data System (ADS)

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

2017-11-01

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

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

NASA Astrophysics Data System (ADS)

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.

Effect of environment on insulation materials, volume 1

NASA Technical Reports Server (NTRS)

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

1973-01-01

Twenty candidate multilayer insulation and insulation related materials were subjected to eight conditions that represent possible operational environments. These exposures include ground contaminants, various operational temperatures, space vacuum, space-vented propellants, and tank leakage. The objective of this program was to obtain and evaluate the data from these exposures to provide both a quantitative and qualitative description of the degradation to certain physical and thermal properties, and from this, to obtain a better understanding of the environmental effects on the insulation performance.

Ultrasonic Guided Waves for Aging Wire Insulation Assessment

NASA Technical Reports Server (NTRS)

Anastasi, Robert F.; Madaras, Eric I.

2001-01-01

Environmentally aged wire insulation can become brittle and crack and thus expose the underlying conductive wire to the potential for short circuits and fire. The feasibility of using ultrasonic guided waves to measure insulation condition was examined. First a simple model to study guided wave propagation in a bare and thin plastic coated wire was examined and then some aviation grade wire samples that had been heat-damaged. Initial measurements indicate that ultrasonic guided wave velocity can be used to monitor insulation stiffness.

Petition to the Environmental Protection Agency to Control Asbestos Emmissions from Spray-On Materials Which Have Been Applied in Public School Buildings for Insulation, Fireproofing, Decorative or Other Purposes.

ERIC Educational Resources Information Center

Environmental Defense Fund, Washington, DC.

This petition requests the Environmental Protection Agency to promulgate regulations in compliance with section 6 of the Toxic Substances Control Act to control asbestos emissions from spray-on materials containing 1 percent or more asbestos that has been applied in public school buildings for insulation, fireproofing, decorative, or other…

Airborne environmental endotoxin: a cross-validation of sampling and analysis techniques.

PubMed Central

Walters, M; Milton, D; Larsson, L; Ford, T

1994-01-01

A standard method for measurement of airborne environmental endotoxin was developed and field tested in a fiberglass insulation-manufacturing facility. This method involved sampling with a capillary-pore membrane filter, extraction in buffer using a sonication bath, and analysis by the kinetic-Limulus assay with resistant-parallel-line estimation (KLARE). Cross-validation of the extraction and assay method was performed by comparison with methanolysis of samples followed by 3-hydroxy fatty acid (3-OHFA) analysis by gas chromatography-mass spectrometry. Direct methanolysis of filter samples and methanolysis of buffer extracts of the filters yielded similar 3-OHFA content (P = 0.72); the average difference was 2.1%. Analysis of buffer extracts for endotoxin content by the KLARE method and by gas chromatography-mass spectrometry for 3-OHFA content produced similar results (P = 0.23); the average difference was 0.88%. The source of endotoxin was gram-negative bacteria growing in recycled washwater used to clean the insulation-manufacturing equipment. The endotoxin and bacteria become airborne during spray cleaning operations. The types of 3-OHFAs in bacteria cultured from the washwater, present in the washwater and in the air, were similar. Virtually all of the bacteria cultured from air and water were gram negative composed mostly of two species, Deleya aesta and Acinetobacter johnsonii. Airborne countable bacteria correlated well with endotoxin (r2 = 0.64). Replicate sampling showed that results with the standard sampling, extraction, and Limulus assay by the KLARE method were highly reproducible (95% confidence interval for endotoxin measurement +/- 0.28 log10). These results demonstrate the accuracy, precision, and sensitivity of the standard procedure proposed for airborne environmental endotoxin. PMID:8161191

Environmental Aging of Polymer-Nano Composites and Release of Carbon Nanotube

EPA Science Inventory

Epoxies are widely used in various applications, including coatings, electronics insulations, and waterproofing applications due to their excellent properties such as good adhesion, electrical insulation, and heat resistance along with the strong mechanical property. Currently, n...

16 CFR 1505.8 - Maximum acceptable material temperatures.

Code of Federal Regulations, 2014 CFR

2014-01-01

... heat-resistant properties, or if the insulation meets the thermal requirements. 4 40 less than melting... 105 insulation on windings or relays, solenoids, etc.: Thermocouple method 2 90 194 Resistance method 110 230 Class 130 insulation system 110 230 Insulation: Varnished-cloth insulation 85 185 Fiber used...

16 CFR 1505.8 - Maximum acceptable material temperatures.

Code of Federal Regulations, 2010 CFR

2010-01-01

... heat-resistant properties, or if the insulation meets the thermal requirements. 4 40 less than melting... 105 insulation on windings or relays, solenoids, etc.: Thermocouple method 2 90 194 Resistance method 110 230 Class 130 insulation system 110 230 Insulation: Varnished-cloth insulation 85 185 Fiber used...

16 CFR 1505.8 - Maximum acceptable material temperatures.

Code of Federal Regulations, 2011 CFR

2011-01-01

... heat-resistant properties, or if the insulation meets the thermal requirements. 4 40 less than melting... 105 insulation on windings or relays, solenoids, etc.: Thermocouple method 2 90 194 Resistance method 110 230 Class 130 insulation system 110 230 Insulation: Varnished-cloth insulation 85 185 Fiber used...

16 CFR 1505.8 - Maximum acceptable material temperatures.

Code of Federal Regulations, 2012 CFR

2012-01-01

... heat-resistant properties, or if the insulation meets the thermal requirements. 4 40 less than melting... 105 insulation on windings or relays, solenoids, etc.: Thermocouple method 2 90 194 Resistance method 110 230 Class 130 insulation system 110 230 Insulation: Varnished-cloth insulation 85 185 Fiber used...

Hydrophobic Characteristics of Composite Insulators in Simulated Inland Arid Desert Environment

NASA Astrophysics Data System (ADS)

Khan, Yasin; Al-Arainy, Abdulrehman Ali; Malik, Nazar Hussain; Qureshi, Muhammad Iqbal

2010-06-01

Presently along with traditional insulators i.e. glass and porcelain, etc., the polymeric insulators are also used world widely. These polymeric insulators are very sensitive to various environmental parameters e.g. UV radiations, heat, etc. The UV radiation level in the central region of Saudi Arabia is high as compared to the recommended IEC-61109 standard for the accelerated aging of the composite insulators. In this study, thermoplastic elastomer (TPE) and Ethylene Propylene Diene Monomer (EPDM) insulators were subjected to accelerated aging stress as per IEC standard as well as modified IEC standard simulating the inland arid desert's atmospheric conditions. The hydrophobic characteristics were studied by measuring the contact angle along the insulator surface before and after the accelerated aging of the samples. It was found that TPE loses its hydrophobic properties more as compared to EPDM insulator. This loss was proportional to the intensity of UV irradiation. The rate of recovery is also low for both the tested materials as compared to Silicone Rubber insulators.

HYDROPHOBIC CHARACTERISTICS OF COMPOSITE INSULATORS IN SIMULATED INLAND ARID DESERT ENVIRONMENT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Yasin; Al-Arainy, Abdulrehman Ali; Malik, Nazar Hussain

2010-06-15

Presently along with traditional insulators i.e. glass and porcelain, etc., the polymeric insulators are also used world widely. These polymeric insulators are very sensitive to various environmental parameters e.g. UV radiations, heat, etc. The UV radiation level in the central region of Saudi Arabia is high as compared to the recommended IEC-61109 standard for the accelerated aging of the composite insulators. In this study, thermoplastic elastomer (TPE) and Ethylene Propylene Diene Monomer (EPDM) insulators were subjected to accelerated aging stress as per IEC standard as well as modified IEC standard simulating the inland arid desert's atmospheric conditions. The hydrophobic characteristicsmore » were studied by measuring the contact angle along the insulator surface before and after the accelerated aging of the samples. It was found that TPE loses its hydrophobic properties more as compared to EPDM insulator. This loss was proportional to the intensity of UV irradiation. The rate of recovery is also low for both the tested materials as compared to Silicone Rubber insulators.« less

New insulation attachment method eliminates compatibility bondline stresses

NASA Technical Reports Server (NTRS)

Schneider, W. C.

1975-01-01

Auger-shaped single-point fastener attaches rigid surface insulation tiles to orbiter shuttle spacecraft. Method can be used to bond wide variety of materials, including insulation, elastomers, and fibrous materials. Since insulation is attached at only one point, insulation and structure are free to form without inducing bond separation.

Development of processing techniques for advanced thermal protection materials

NASA Technical Reports Server (NTRS)

Selvaduray, Guna S.

1995-01-01

The main purpose of this work has been in the development and characterization of materials for high temperature applications. Thermal Protection Systems (TPS) are constantly being tested, and evaluated for increased thermal shock resistance, high temperature dimensional stability, and tolerance to environmental effects. Materials development was carried out through the use of many different instruments and methods, ranging from extensive elemental analysis to physical attributes testing. The six main focus areas include: (1) protective coatings for carbon/carbon composites; (2) TPS material characterization; (3) improved waterproofing for TPS; (4) modified ceramic insulation for bone implants; (5) improved durability ceramic insulation blankets; and (6) ultra-high temperature ceramics. This report describes the progress made in these research areas during this contract period.

Electron Emission Properties of Insulator Materials Pertinent to the International Space Station

NASA Technical Reports Server (NTRS)

Thomson, C. D.; Zavyalov, V.; Dennison, J. R.; Corbridge, Jodie

2004-01-01

We present the results of our measurements of the electron emission properties of selected insulating and conducting materials used on the International Space Station (ISS). Utah State University (USU) has performed measurements of the electron-, ion-, and photon-induced electron emission properties of conductors for a few years, and has recently extended our capabilities to measure electron yields of insulators, allowing us to significantly expand current spacecraft material charging databases. These ISS materials data are used here to illustrate our various insulator measurement techniques that include: i) Studies of electron-induced secondary and backscattered electron yield curves using pulsed, low current electron beams to minimize deleterious affects of insulator charging. ii) Comparison of several methods used to determine the insulator 1st and 2nd crossover energies. These incident electron energies induce unity total yield at the transition between yields greater than and less than one with either negative or positive charging, respectively. The crossover energies are very important in determining both the polarity and magnitude of spacecraft surface potentials. iii) Evolution of electron emission energy spectra as a function of insulator charging used to determine the surface potential of insulators. iv) Surface potential evolution as a function of pulsed-electron fluence to determine how quickly insulators charge, and how this can affect subsequent electron yields. v) Critical incident electron energies resulting in electrical breakdown of insulator materials and the effect of breakdown on subsequent emission, charging and conduction. vi) Charge-neutralization techniques such as low-energy electron flooding and UV light irradiation to dissipate both positive and negative surface potentials during yield measurements. Specific ISS materials being tested at USU include chromic and sulfuric anodized aluminum, RTV-silicone solar array adhesives, solar cell cover glasses, Kapton, and gold. Further details of the USU testing facilities, the instrumentation used for insulator measurements, and the NASA/SEE Charge Collector materials database are provided in other Spacecraft Charging Conference presentations (Dennison, 2003b). The work presented was supported in part by the NASA Space Environments and Effects (SEE) Program, the Boeing Corporation, and a NASA Graduate Fellowship. Samples were supplied by Boeing, the Environmental Effects Group at Marshall Space Flight Center, and Sheldahl, Inc.

Preparation and properties of the multi-layer aerogel thermal insulation composites

NASA Astrophysics Data System (ADS)

Wang, Miao; Feng, Junzong; Jiang, Yonggang; Zhang, Zhongming; Feng, Jian

2018-03-01

Multi-layer insulation materials possess low radiation thermal conductivity, and excellent thermal insulation property in a vacuum environment. However, the spacers of the traditional multi-layer insulation materials are mostly loose fibers, which lead to more sensitive to the vacuum environmental of serviced. With the vacuum degree declining, gas phases thermal convection increase obviously, and the reflective screen will be severe oxidation, all of these make the thermal insulation property of traditional multi-layer insulation deteriorate, thus limits its application scope. In this paper, traditional multi-layer insulation material is combined with aerogel and obtain a new multi-layer aerogel thermal insulation composite, and the effects of the number, thickness and type of the reflective screens on the thermal insulation properties of the multi-layer composites are also studied. The result is that the thermal insulation property of the new type multi-layer aerogel composites is better than the pure aerogel composites and the traditional multi-layer insulation composites. When the 0.01 mm stainless steel foil as the reflective screen, and the aluminum silicate fiber and silica aerogel as the spacer layer, the layer density of composite with the best thermal insulation property is one layer per millimeter at 1000 °C.

Heat Transfer in High-Temperature Fibrous Insulation

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran

2002-01-01

The combined radiation/conduction heat transfer in high-porosity, high-temperature fibrous insulations was investigated experimentally and numerically. The effective thermal conductivity of fibrous insulation samples was measured over the temperature range of 300-1300 K and environmental pressure range of 1.33 x 10(exp -5)-101.32 kPa. The fibrous insulation samples tested had nominal densities of 24, 48, and 72 kilograms per cubic meter and thicknesses of 13.3, 26.6 and 39.9 millimeters. Seven samples were tested such that the applied heat flux vector was aligned with local gravity vector to eliminate natural convection as a mode of heat transfer. Two samples were tested with reverse orientation to investigate natural convection effects. It was determined that for the fibrous insulation densities and thicknesses investigated no heat transfer takes place through natural convection. A finite volume numerical model was developed to solve the governing combined radiation and conduction heat transfer equations. Various methods of modeling the gas/solid conduction interaction in fibrous insulations were investigated. The radiation heat transfer was modeled using the modified two-flux approximation assuming anisotropic scattering and gray medium. A genetic-algorithm based parameter estimation technique was utilized with this model to determine the relevant radiative properties of the fibrous insulation over the temperature range of 300-1300 K. The parameter estimation was performed by least square minimization of the difference between measured and predicted values of effective thermal conductivity at a density of 24 kilograms per cubic meters and at nominal pressures of 1.33 x 10(exp -4) and 99.98 kPa. The numerical model was validated by comparison with steady-state effective thermal conductivity measurements at other densities and pressures. The numerical model was also validated by comparison with a transient thermal test simulating reentry aerodynamic heating conditions.

Method and apparatus for filling thermal insulating systems

DOEpatents

Arasteh, Dariush K.

1992-01-01

A method for filling insulated glazing units is disclosed. The method utilizes a vacuum chamber in which the insulated glazing units are placed. The insulated glazing units and vacuum chamber are evacuated simultaneously. The units are then refilled with a low conductance gas such as Krypton while the chamber is simultaneously refilled with air.

Prototype Aerogel Insulation for Melamine-Foam Substitute: Critical Space Station Express Rack Technology

NASA Technical Reports Server (NTRS)

Noever, David A.; Sibille, Laurent; Smith, David; Cronise, Raymond

1998-01-01

There is a current lack of environmentally acceptable foams to insulate Long-Duration Human Spaceflight Missions, including the experimental Express Rack for the Space Station. A recent 60-day manned test in a sealed chamber at Johnson Space Center (JSC) was nearly aborted, because of persistently high formaldehyde concentrations in the chamber. Subsequent investigation showed that the source was melamine foam (used extensively for acoustic insulation). The thermal and acoustic potential for melamine-foam substitutes is evaluated for scale-up to a silica-based foam and aerogel, which is environmentally benign for long duration space flight. These features will be discussed in reference to an aerogel prototype to: 1) assemble material strength data for various formulated aerogels, both silica and organic carbon aerogels; 2) assemble the aerogel into panels of mylar/vacuum-encapsulated rigid boards which can be molded in various shapes and rigidities; and 3) describe a process for space applications for formaldehyde-free, long duration thermal and acoustic insulators.

Effective Thermal Conductivity of High Temperature Insulations for Reusable Launch Vehicles

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran

1999-01-01

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

Method and apparatus for filling thermal insulating systems

DOEpatents

Arasteh, D.K.

1992-01-14

A method for filling insulated glazing units is disclosed. The method utilizes a vacuum chamber in which the insulated glazing units are placed. The insulated glazing units and vacuum chamber are evacuated simultaneously. The units are then refilled with a low conductance gas such as Krypton while the chamber is simultaneously refilled with air. 3 figs.

Cladding Attachment Over Thick Exterior Insulating Sheathing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, P.; Eng, P.; Lepage, R.

The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location (Straube and Smegal 2009, Pettit 2009, Joyce 2009, Ueno 2010). The research presented in this report is intended to help develop a better understanding of the systemmore » mechanics involved and the potential for environmental exposure induced movement between the furring strip and the framing. BSC sought to address the following research questions: 1.What are the relative roles of the mechanisms and the magnitudes of the force that influence the vertical displacement resistance of the system? 2.Can the capacity at a specified deflection be reliably calculated using mechanics based equations? 3.What are the impacts of environmental exposure on the vertical displacement of furring strips attached directly through insulation back to a wood structure?« less

Cladding Attachment Over Thick Exterior Insulating Sheathing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, P.; Eng, P.; Lepage, R.

The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location (Straube and Smegal 2009, Pettit 2009, Joyce 2009, Ueno 2010). The research presented in this report is intended to help develop a better understanding of the systemmore » mechanics involved and the potential for environmental exposure induced movement between the furring strip and the framing. BSC sought to address the following research questions: 1. What are the relative roles of the mechanisms and the magnitudes of the force that influence the vertical displacement resistance of the system? 2. Can the capacity at a specified deflection be reliably calculated using mechanics based equations? 3. What are the impacts of environmental exposure on the vertical displacement of furring strips attached directly through insulation back to a wood structure?« less

Use of reagents to convert chrysotile and amosite asbestos used as insulation or protection for metal surfaces

DOEpatents

Sugama, Toshifumi; Petrakis, Leon

2000-12-12

A composition for converting asbestos-containing material, covering metal pipes or other metal surfaces, to non-regulated, environmentally benign-materials, and inhibiting the corrosion of the metal pipes or other metal surfaces. The composition comprises a combination of at least two multiple-functional group reagents, in which each reagent includes a Fluro acid component and a corrosion inhibiting compoment. A method for converting asbestos-containing material, covering metal pipes or other metal surfaces, to non-regulated, environmentally benign-materials, and inhibiting the corrosion of the metal pipes or other metal surfaces is also provided.

Environmental Influence of Gravity and Pressure on Arc Tracking of Insulated Wires Investigated

NASA Technical Reports Server (NTRS)

2005-01-01

Momentary short-circuit arcs between a defective polyimide-insulated wire and another conductor may thermally char (pyrolize) the insulating material. The charred polyimide, being conductive, can sustain the short-circuit arc, which may propagate along the wire through continuous pyrolization of the polyimide insulation (arc tracking). If the arcing wire is part of a multiple-wire bundle, the polyimide insulation of other wires within the bundle may become thermally charred and start arc tracking also (flash over). Such arc tracking can lead to complete failure of an entire wire bundle, causing other critical spacecraft or aircraft failures. Unfortunately, all tested candidate wire insulations for aerospace vehicles were susceptible to arc tracking. Therefore, a test procedure was designed at the NASA Lewis Research Center to select the insulation type least susceptible to arc tracking. This test procedure addresses the following three areas of concern: (1) probability of initiation, (2) probability of reinitiation (restrike), and (3) extent of arc tracking damage (propagation rate). Item 2 (restrike probability) is an issue if power can be terminated from and reapplied to the arcing wire (by a switch, fuse, or resettable circuit breaker). The degree of damage from an arcing event (item 3) refers to how easily the arc chars nearby insulation and propagates along the wire pair. Ease of nearby insulation charring can be determined by measuring the rate of arc propagation. Insulation that chars easily will propagate the arc faster than insulation that does not char very easily. A popular polyimide insulated wire for aerospace vehicles, MIL-W-81381, was tested to determine a degree of damage from an arcing event (item 3) in the following three environments: (1) microgravity with air at 1-atm pressure, (2) 1g with air at 1 atm, and (3) 1g within a 10^-6 Torr vacuum. The microgravity 1-atm air was the harshest environment, with respect to the rate of damage of arc tracking, for the 20 AWG (American Wiring Gauge) MIL-W-81381 wire insulation type . The vacuum environment resulted in the least damage. Further testing is planned to determine if the environmental results are consistent between insulation types and to evaluate the other two parameters associated with arc tracking susceptibility.

System for maintaining materials at freezer temperatures for shipping

DOEpatents

Schabron, John F [Laramie, WY; Sorini-Wong, Susan S [Laramie, WY

2007-08-28

At least one embodiment of the inventive technology relates to a frozen environmental sample temperature control system that comprises a frozen formulation having water in an amount from substantially 87% to 78% by weight of the formulation, and salt in an amount from substantially 13% to 22% by weight of the formulation, the system further including at least one container containing the frozen formulation; and a cooler having insulating material disposed between an outer wall and an inner surface that defines an inner chamber into which the at least one container and the at least one frozen environmental sample may be placed for storage and/or transport. Various embodiments may incorporate specific types of insulating material and/or adaptations to an inner surface of the cooler to enhance the insulation effected thereby.

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

NASA Technical Reports Server (NTRS)

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.

Advances in cryogenic foam insulations.

NASA Technical Reports Server (NTRS)

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

1971-01-01

Description of a discretely oriented thread-reinforced polyurethane foam thermal insulation system for liquid hydrogen fuel tanks. The 3-D foam and glass liner composite is designed to be adhesively bonded to the inside surface of the tank wall and to be in direct contact with liquid hydrogen. All elements of this insulation composite are capable of sustaining the loads and environmental conditions imposed by testing under simulated Space Shuttle vehicle requirements at temperatures between -423 and +350 F.

Basalt fiber and nanoclay compositions, articles incorporating the same, and methods of insulating a rocket motor with the same

NASA Technical Reports Server (NTRS)

Gajiwala, Himansu M. (Inventor)

2010-01-01

An insulation composition that comprises at least one nitrile butadiene rubber, basalt fibers, and nanoclay is disclosed. Further disclosed is an insulation composition that comprises polybenzimidazole fibers, basalt fibers, and nanoclay. The basalt fibers may be present in the insulation compositions in a range of from approximately 1% by weight to approximately 6% by weight of the total weight of the insulation composition. The nanoclay may be present in the insulation compositions in a range of from approximately 5% by weight to approximately 10% by weight of the total weight of the insulation composition. Rocket motors including the insulation compositions and methods of insulating a rocket motor are also disclosed.

Rocket motors incorporating basalt fiber and nanoclay compositions and methods of insulating a rocket motor with the same

NASA Technical Reports Server (NTRS)

Gajiwala, Himansu M. (Inventor)

2011-01-01

An insulation composition that comprises at least one nitrile butadiene rubber, basalt fibers, and nanoclay is disclosed. Further disclosed is an insulation composition that comprises polybenzimidazole fibers, basalt fibers, and nanoclay. The basalt fibers may be present in the insulation compositions in a range of from approximately 1% by weight to approximately 6% by weight of the total weight of the insulation composition. The nanoclay may be present in the insulation compositions in a range of from approximately 5% by weight to approximately 10% by weight of the total weight of the insulation composition. Rocket motors including the insulation compositions and methods of insulating a rocket motor are also disclosed.

77 FR 50411 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-21

... environmental control system (ECS) wrapped with BMS 8-39 or Aeronautical Materials Specifications (AMS) 3570... were assembled with duct assemblies in the ECS wrapped with BMS 8-39 urethane foam insulation, a... ECS with burned BMS 8-39 urethane foam insulation. We issued these ADs to prevent a potential...

Integration of body temperature into the analysis of energy expenditure in the mouse

PubMed Central

Abreu-Vieira, Gustavo; Xiao, Cuiying; Gavrilova, Oksana; Reitman, Marc L.

2015-01-01

Objectives We quantified the effect of environmental temperature on mouse energy homeostasis and body temperature. Methods The effect of environmental temperature (4–33 °C) on body temperature, energy expenditure, physical activity, and food intake in various mice (chow diet, high-fat diet, Brs3-/y, lipodystrophic) was measured using continuous monitoring. Results Body temperature depended most on circadian phase and physical activity, but also on environmental temperature. The amounts of energy expenditure due to basal metabolic rate (calculated via a novel method), thermic effect of food, physical activity, and cold-induced thermogenesis were determined as a function of environmental temperature. The measured resting defended body temperature matched that calculated from the energy expenditure using Fourier's law of heat conduction. Mice defended a higher body temperature during physical activity. The cost of the warmer body temperature during the active phase is 4–16% of total daily energy expenditure. Parameters measured in diet-induced obese and Brs3-/y mice were similar to controls. The high post-mortem heat conductance demonstrates that most insulation in mice is via physiological mechanisms. Conclusions At 22 °C, cold-induced thermogenesis is ∼120% of basal metabolic rate. The higher body temperature during physical activity is due to a higher set point, not simply increased heat generation during exercise. Most insulation in mice is via physiological mechanisms, with little from fur or fat. Our analysis suggests that the definition of the upper limit of the thermoneutral zone should be re-considered. Measuring body temperature informs interpretation of energy expenditure data and improves the predictiveness and utility of the mouse to model human energy homeostasis. PMID:26042200

Exploratory Environmental Tests of Several Heat Shields

NASA Technical Reports Server (NTRS)

Goodman, George P.; Betts, John, Jr.

1961-01-01

Exploratory tests have been conducted with several conceptual radiative heat shields of composite construction. Measured transient temperature distributions were obtained for a graphite heat shield without insulation and with three types of insulating materials, and for a metal multipost heat shield, at surface temperatures of approximately 2,000 F and 1,450 F, respectively, by use of a radiant-heat facility. The graphite configurations suffered loss of surface material under repeated irradiation. Temperature distribution calculated for the metal heat shield by a numerical procedure was in good agreement with measured data. Environmental survival tests of the graphite heat shield without insulation, an insulated multipost heat shield, and a stainless-steel-tile heat shield were made at temperatures of 2,000 F and dynamic pressures of approximately 6,000 lb/sq ft, provided by an ethylene-heated jet operating at a Mach number of 2.0 and sea-level conditions. The graphite heat shield survived the simulated aerodynamic heating and pressure loading. A problem area exists in the design and materials for heat-resistant fasteners between the graphite shield and the base structure. The insulated multipost heat shield was found to be superior to the stainless-steel-tile heat shield in retarding heat flow. Over-lapped face-plate joints and surface smoothness of the insulated multi- post heat shield were not adversely affected by the test environment. The graphite heat shield without insulation survived tests made in the acoustic environment of a large air jet. This acoustic environment is random in frequency and has an overall noise level of 160 decibels.

Study on Insulation Diagnosis of Power Lines in Apartment Houses

NASA Astrophysics Data System (ADS)

Okamoto, Tatsuki; Taki, Shoji; Fukui, Toshiaki; Soga, Akiya; Ezure, Shoichiro; Asano, Jun-Ichi; Uto, Yukio

Insulation diagnosis is vital issue for safety of urban lives despite of the difficulty of power interruption even for the diagnosis. Recently, live-line insulation diagnosis becomes more important and realistic to maintain good insulation conditions of power lines in apartment houses in wide range of residential sizes. This paper describes new trend of insulation diagnosis of power lines of apartment houses based on clip-on current measurement method with a lot of live-line measurement data and also describes the applicability of new live-line insulation diagnostic method.

Minimization of the negative influence on the biosphere in heavy oil extraction and ecologically clean technology for the injection of the steam with supercritical parameters in oil strata on the basis of new ecologically clean tubing pipes with heat-resistant coatings

NASA Astrophysics Data System (ADS)

Komkov, M. A.; Moiseev, V. A.; Tarasov, V. A.; Timofeev, M. P.

2015-12-01

Some ecological problems related to heavy-oil extraction and ways for minimizing the negative impacts of this process on the biosphere are discussed. The ecological hazard of, for example, frequently used multistage hydraulic fracturing of formation is noted and the advantages and perspectives of superheated steam injection are considered. Steam generators of a new type and ecologically clean and costeffective insulating for tubing pipes (TPs) are necessary to develop the superheated steam injection method. The article is devoted to solving one of the most important and urgent tasks, i.e., the development and usage of lightweight, nonflammable, environmentally safe, and cost-effective insulating materials. It is shown that, for tubing shielding operating at temperatures up to 420°C, the most effective thermal insulation is a highly porous material based on basalt fiber. The process of filtration deposition of short basalt fibers with a bunch of alumina thermal insulation tubing pipe coatings in the form of cylinders and cylindrical shells from liquid pulp is substantiated. Based on the thermophysical characteristics of basalt fibers and on the technological features of manufacturing highly porous coating insulation, the thickness of a tubing pipe is determined. During the prolonged pumping of the air at an operating temperature of 400°C in the model sample of tubing pipes with insulation and a protective layer, we find that the surface temperature of the thermal barrier coating does not exceed 60°C. Introducing the described technology will considerably reduce the negative impact of heavy-oil extraction on the biosphere.

Heat strain in cold.

PubMed

Rintamäki, Hannu; Rissanen, Sirkka

2006-07-01

In spite of increased environmental cold stress, heat strain is possible also in a cold environment. The body heat balance depends on three factors: environmental thermal conditions, metabolic heat production and thermal insulation of clothing and other protective garments. As physical exercise may increase metabolic heat production from rest values by ten times or even more, the required thermal insulation of clothing may vary accordingly. However, in most outdoor work, and often in indoor cold work, too, the thermal insulation of clothing is impractical, difficult or impossible to adjust according to the changes in physical activity. This is especially true with whole body covering garments like chemical protective clothing. As a result of this imbalance, heat strain may develop. In cold all the signs of heat strain (core temperature above 38 degrees C, warm or hot thermal sensations, increased cutaneous circulation and sweating) may not be present at the same time. Heat strain in cold may be whole body heat strain or related only to torso or core temperature. Together with heat strain in torso or body core, there can be at the same time even cold strain in peripheral parts and/or superficial layers of the body. In cold environment both the preservation of insulation and facilitation of heat loss are important. Development of clothing design is still needed to allow easy adjustments of thermal insulation.

Effects of environmental exposure on cryogenic thermal insulation materials

NASA Technical Reports Server (NTRS)

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

1973-01-01

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

Theoretical study of the decomposition mechanism of environmentally friendly insulating medium C3F7CN in the presence of H2O in a discharge

NASA Astrophysics Data System (ADS)

Zhang, Xiaoxing; Li, Yi; Xiao, Song; Tian, Shuangshuang; Deng, Zaitao; Tang, Ju

2017-08-01

C3F7CN has been the focus of the alternative gas research field over the past two years because of its excellent insulation properties and environmental characteristics. Experimental studies on its insulation performance have made many achievements. However, few studies on the formation mechanism of the decomposition components exist. A discussion of the decomposition characteristics of insulating media will provide guidance for scientific experimental research and the work that must be completed before further engineering application. In this study, the decomposition mechanism of C3F7CN in the presence of trace H2O under discharge was calculated based on the density functional theory and transition state theory. The reaction heat, Gibbs free energy, and activation energy of different decomposition pathways were investigated. The ionization parameters and toxicity of C3F7CN and various decomposition products were analyzed from the molecular structure perspective. The formation mechanism of the C3F7CN discharge decomposition components and the influence of trace water were evaluated. This paper confirms that C3F7CN has excellent decomposition characteristics, which provide theoretical support for later experiments and related engineering applications. However, the existence of trace water has a negative impact on C3F7CN’s insulation performance. Thus, strict trace water content standards should be developed to ensure dielectric insulation and the safety of maintenance personnel.

Use Of Superacids To Digest Chrysotile And Amosite Asbestos In Simple Mixtures Or Matrices Found In Building Materials Compositions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugama, Toshifumi; Petrakis, Leon; Webster, Ronald P.

A composition for converting asbestos-containing material to environmentally benign components is provided. The composition comprises a flouro acid decomposing agent which can be applied to either amosite-containing thermal insulation or chrysotile-containing fire-proof material or to any asbestos-containing material which includes of chrysotile and amosite asbestos. The fluoro acid decomposing agent includes FP(O)(OH).sub.2, hexafluorophosphoric acid, a mixture of hydrofluoric and phosphoric acid and a mixture of hexafluorophosphoric acid and phosphoric acid. A method for converting asbestos-containing material to environmentally benign components is also provided

Use of super acids to digest chrysotile and amosite asbestos in simple mixtures or matrices found in building materials compositions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugama, T.; Petrakis, L.; Webster, R.P.

A composition for converting asbestos-containing material to environmentally benign components is provided. The composition comprises a fluoro acid decomposing agent which can be applied to either amosite-containing thermal insulation or chrysotile-containing fire-proof material or to any asbestos-containing material which includes of chrysotile and amosite asbestos. The fluoro acid decomposing agent includes FP{sub 0}(OH){sub 2}, hexafluorophosphoric acid, a mixture of hydrofluoric and phosphoric acid and a mixture of hexafluorophosphoric acid and phosphoric acid. A method for converting asbestos-containing material to environmentally benign components is also provided.

Slab edge insulating form system and methods

DOEpatents

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.

Reducing DNA context dependence in bacterial promoters

PubMed Central

Carr, Swati B.; Densmore, Douglas M.

2017-01-01

Variation in the DNA sequence upstream of bacterial promoters is known to affect the expression levels of the products they regulate, sometimes dramatically. While neutral synthetic insulator sequences have been found to buffer promoters from upstream DNA context, there are no established methods for designing effective insulator sequences with predictable effects on expression levels. We address this problem with Degenerate Insulation Screening (DIS), a novel method based on a randomized 36-nucleotide insulator library and a simple, high-throughput, flow-cytometry-based screen that randomly samples from a library of 436 potential insulated promoters. The results of this screen can then be compared against a reference uninsulated device to select a set of insulated promoters providing a precise level of expression. We verify this method by insulating the constitutive, inducible, and repressible promotors of a four transcriptional-unit inverter (NOT-gate) circuit, finding both that order dependence is largely eliminated by insulation and that circuit performance is also significantly improved, with a 5.8-fold mean improvement in on/off ratio. PMID:28422998

Evaluating uncertainty in environmental life-cycle assessment. A case study comparing two insulation options for a Dutch one-family dwelling.

PubMed

Huijbregts, Mark A J; Gilijamse, Wim; Ragas, Ad M J; Reijnders, Lucas

2003-06-01

The evaluation of uncertainty is relatively new in environmental life-cycle assessment (LCA). It provides useful information to assess the reliability of LCA-based decisions and to guide future research toward reducing uncertainty. Most uncertainty studies in LCA quantify only one type of uncertainty, i.e., uncertainty due to input data (parameter uncertainty). However, LCA outcomes can also be uncertain due to normative choices (scenario uncertainty) and the mathematical models involved (model uncertainty). The present paper outlines a new methodology that quantifies parameter, scenario, and model uncertainty simultaneously in environmental life-cycle assessment. The procedure is illustrated in a case study that compares two insulation options for a Dutch one-family dwelling. Parameter uncertainty was quantified by means of Monte Carlo simulation. Scenario and model uncertainty were quantified by resampling different decision scenarios and model formulations, respectively. Although scenario and model uncertainty were not quantified comprehensively, the results indicate that both types of uncertainty influence the case study outcomes. This stresses the importance of quantifying parameter, scenario, and model uncertainty simultaneously. The two insulation options studied were found to have significantly different impact scores for global warming, stratospheric ozone depletion, and eutrophication. The thickest insulation option has the lowest impact on global warming and eutrophication, and the highest impact on stratospheric ozone depletion.

Results of shuttle EMU thermal vacuum tests incorporating an infrared imaging camera data acquisition system

NASA Technical Reports Server (NTRS)

Anderson, James E.; Tepper, Edward H.; Trevino, Louis A.

1991-01-01

Manned tests in Chamber B at NASA JSC were conducted in May and June of 1990 to better quantify the Space Shuttle Extravehicular Mobility Unit's (EMU) thermal performance in the cold environmental extremes of space. Use of an infrared imaging camera with real-time video monitoring of the output significantly added to the scope, quality and interpretation of the test conduct and data acquisition. Results of this test program have been effective in the thermal certification of a new insulation configuration and the '5000 Series' glove. In addition, the acceptable thermal performance of flight garments with visually deteriorated insulation was successfully demonstrated, thereby saving significant inspection and garment replacement cost. This test program also established a new method for collecting data vital to improving crew thermal comfort in a cold environment.

Dry and wet arc track propagation resistance testing

NASA Technical Reports Server (NTRS)

Beach, Rex

1995-01-01

The wet arc-propagation resistance test for wire insulation provides an assessment of the ability of an insulation to prevent damage in an electrical environment. Results of an arc-propagation test may vary slightly due to the method of arc initiation; therefore a standard test method must be selected to evaluate the general arc-propagation resistance characteristics of an insulation. This test method initiates an arc by dripping salt water over pre-damaged wires which creates a conductive path between the wires. The power supply, test current, circuit resistances, and other variables are optimized for testing 20 guage wires. The use of other wire sizes may require modifications to the test variables. The dry arc-propagation resistance test for wire insulation also provides an assessment of the ability of an insulation to prevent damage in an electrical arc environment. In service, electrical arcs may originate form a variety of factors including insulation deterioration, faulty installation, and chafing. Here too, a standard test method must be selected to evaluate the general arc-propagation resistance characteristics of an insulation. This test method initiates an arc with a vibrating blade. The test also evaluates the ability of the insulation to prevent further arc-propagation when the electrical arc is re-energized.

Systems and Methods for Providing Insulation

NASA Technical Reports Server (NTRS)

Golden, Johnny L. (Inventor)

2015-01-01

Systems and methods provide a multi-layer insulation (MLI) that includes a plurality of sealed metalized volumes in a stacked arrangement, wherein the plurality of sealed metalized volumes encapsulate a gas therein, with the gas having one of a thermal insulating property, an acoustic insulating property, or a combination insulating property thereof. The MLI also includes at least one spacer between adjacent sealed metalized volumes of the plurality of sealed metalized volumes and a protective cover surrounding the plurality of sealed metalized volumes.

Analysis and comparison of magnetic sheet insulation tests

NASA Astrophysics Data System (ADS)

Marion-Péra, M. C.; Kedous-Lebouc, A.; Cornut, B.; Brissonneau, P.

1994-05-01

Magnetic circuits of electrical machines are divided into coated sheets in order to limit eddy currents. The surface insulation resistance of magnetic sheets is difficult to evaluate because it depends on parameters like pressure and covers a wide range of values. Two methods of measuring insulation resistance are analyzed: the standardized 'Franklin device' and a tester developed by British Steel Electrical. Their main drawback is poor local repeatability. The Franklin method allows better quality control of industrial process because it measures only one insulating layer at a time. It also gives more accurate images of the distribution of possible defects. Nevertheless, both methods lead to similar classifications of insulation efficiency.

Relationship between Leakage Current and Pollution Deposits on the Surface of Polymeric Insulator

NASA Astrophysics Data System (ADS)

Miyake, Takuma; Seo, Yuya; Sakoda, Tatsuya; Otsubo, Masahisa

Application of polymeric materials used for housing insulators is considered. However, because polymeric insulator is organic matter, the aged deterioration is anxious. The lifetime of polymeric insulator is influenced by environmental conditions such as ultraviolet, acid rain, and polluted deposits. A change of the surface condition of polymeric material causes the dry band arc discharge and the discharge may lower the insulation strength. To investigate the relationship between insoluble pollution and occurrence of dry band arc discharge, we performed a salt-fog test with ethylene vinyl acetate (EVA) samples. The results showed that the heavy erosion caused by frequent dry band arc discharges occurred even in the case of a light polluted condition. Additionally, a very characteristic increase tendency in leakage current with a period of about 5 h was observed during the mist period.

The collection of images of an insulator taken outdoors in varying lighting conditions with additional laser spots.

PubMed

Tomaszewski, Michał; Ruszczak, Bogdan; Michalski, Paweł

2018-06-01

Electrical insulators are elements of power lines that require periodical diagnostics. Due to their location on the components of high-voltage power lines, their imaging can be cumbersome and time-consuming, especially under varying lighting conditions. Insulator diagnostics with the use of visual methods may require localizing insulators in the scene. Studies focused on insulator localization in the scene apply a number of methods, including: texture analysis, MRF (Markov Random Field), Gabor filters or GLCM (Gray Level Co-Occurrence Matrix) [1], [2]. Some methods, e.g. those which localize insulators based on colour analysis [3], rely on object and scene illumination, which is why the images from the dataset are taken under varying lighting conditions. The dataset may also be used to compare the effectiveness of different methods of localizing insulators in images. This article presents high-resolution images depicting a long rod electrical insulator under varying lighting conditions and against different backgrounds: crops, forest and grass. The dataset contains images with visible laser spots (generated by a device emitting light at the wavelength of 532 nm) and images without such spots, as well as complementary data concerning the illumination level and insulator position in the scene, the number of registered laser spots, and their coordinates in the image. The laser spots may be used to support object-localizing algorithms, while the images without spots may serve as a source of information for those algorithms which do not need spots to localize an insulator.

Heat Transfer In High-Temperature Multilayer Insulation

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran; Miller, Stephen D.; Cunnington, George R.

2006-01-01

The combined radiation/conduction heat transfer in high-temperature multilayer insulations for typical reentry of reusable launch vehicles from low Earth orbit was investigated experimentally and numerically. The high-temperature multilayer insulation investigated consisted of gold-coated reflective foils separated by alumina fibrous insulation spacers. The steady-state heat transfer through four multilayer insulation configurations was investigated experimentally over the temperature range of 300-1300 K and environmental pressure range of 1.33 10(exp -5)-101.32 kPa. It was shown that including the reflective foils reduced the effective thermal conductivity compared to fibrous insulation sample at 1.5 times the density of the multilayer sample. A finite volume numerical model was developed to solve the governing combined radiation/conduction heat transfer equations. The radiation heat transfer in the fibrous insulation spacers was modeled using the modified two-flux approximation assuming anisotropic scattering and gray medium. The numerical model was validated by comparison with steady-state experimental data. The root mean square deviation between the predicted and measured effective thermal conductivity of the samples was 9.5%.

Biophysical evaluation of footwear for cold-weather climates.

PubMed

Santee, W R; Endrusick, T L

1988-02-01

Proper selection of footwear for cold-wet environments is important in determining individual performance and comfort. Testing only total dry insulation (It) is not a wholly adequate basis for boot selection. The present study demonstrates an effective method for evaluating the effects of surface moisture on boot insulation. This method allows a more knowledgeable selection of footwear for cold-wet climates. In this study, regional insulation values were obtained under dry conditions, then during a soak in shallow water, and finally for insulation recovery after removal from water. Results for seven boots show no advantage of presently used synthetic materials during short soak episodes. Insulated leather-synthetic boots, however, recovered to dry insulation levels more rapidly than more traditional insulated leather boots. Rubber waterproof bottoms were the most effective boot construction for retaining insulation levels during water exposure.

Insulation Technology in Dry Air and Vacuum for a 72kV Low Pressured Dry Air Insulated Switchgear

NASA Astrophysics Data System (ADS)

Yoshida, Tadahiro; Koga, Hiromi; Harada, Takakazu; Miki, Shinichi; Arioka, Masahiro; Sato, Shinji; Yoshida, Satoru; Inoue, Naoaki; Maruyama, Akihiko; Takeuchi, Toshie

A new 72kV rated low pressured dry air insulated switchgear applying electromagnetic actuation and function that supports CBM has been developed. First, dielectric characteristics in dry air under lightning impulse application has been investigated at bare and insulator covered electrodes. Dependence of the breakdown electric field strength on the effective area has been clarified to apply the configuration design of the insulation mold for the vacuum interrupter. In addition, moisture volume dependence on surface resistance has been clarified to decide moisture volume in gas pressure tank. Next, a new vacuum circuit breaker (VCB) has been designed. To keep dimensions from former 72kV SF6 gas insulated switchgear, distance between contacts in vacuum interrupter is needed to be shorter than that of former switchgear. Voltage withstand capability between electrodes practically designed for vacuum interrupter has been investigated under dc voltage application simulated the small capacitive current breaking test. Gap configuration including contacts and slits has been optimized and distance has been shortened 11% from former switchgear. As a result, the new low pressured dry air insulated switchgear has been designed comparably in outer size to former SF6 gas insulated switchgear. Using dry air as an insulation medium with low pressure has been able to reduce the environmental burden.

Characterizing the Performance of the Wheel Electrostatic Spectrometer

NASA Technical Reports Server (NTRS)

Johansen, Michael R.; Mackey, P. J.; Holbert, E.; Calle, C. I.; Clements, J. S.

2013-01-01

Insulators need to be discharged after each wheel revolution. Sensor responses repeatable within one standard deviation in the noise of the signal. Insulators may not need to be cleaned after each revolution. Parent Technology- Mars Environmental Compatibility Assessment/Electrometer Electrostatic sensors with dissimilar cover insulators Protruding insulators tribocharge against regolith simulant Developed for use on the scoop for the 2001 Mars Odyssey lander Wheel Electrostatic Spectrometer Embedded electrostatic sensors in prototype Martian rover wheel If successful, this technology will enable constant electrostatic testing on Mars Air ionizing fan used to neutralize the surface charge on cover insulators . WES rolled on JSClA lunar simulant Control experiment -Static elimination not conducted between trials -Capacitor discharged after each experiment Charge neutralization experiment -Static elimination conducted between trials -Capacitor discharged after each experiment. Air ionizing fan used on insulators after each wheel revolution Capacitor discharged after each trial Care was taken to roll WES with same speed/pressure Error bars represent one standard deviation in the noise of e ach sensor

Ideology of a multiparametric system for estimating the insulation system of electric machines on the basis of absorption testing methods

NASA Astrophysics Data System (ADS)

Kislyakov, M. A.; Chernov, V. A.; Maksimkin, V. L.; Bozhin, Yu. M.

2017-12-01

The article deals with modern methods of monitoring the state and predicting the life of electric machines. In 50% of the cases of failure in the performance of electric machines is associated with insulation damage. As promising, nondestructive methods of control, methods based on the investigation of the processes of polarization occurring in insulating materials are proposed. To improve the accuracy of determining the state of insulation, a multiparametric approach is considered, which is a basis for the development of an expert system for estimating the state of health.

Comparison of three different prehospital wrapping methods for preventing hypothermia - a crossover study in humans

PubMed Central

2011-01-01

Background Accidental hypothermia increases mortality and morbidity in trauma patients. Various methods for insulating and wrapping hypothermic patients are used worldwide. The aim of this study was to compare the thermal insulating effects and comfort of bubble wrap, ambulance blankets / quilts, and Hibler's method, a low-cost method combining a plastic outer layer with an insulating layer. Methods Eight volunteers were dressed in moistened clothing, exposed to a cold and windy environment then wrapped using one of the three different insulation methods in random order on three different days. They were rested quietly on their back for 60 minutes in a cold climatic chamber. Skin temperature, rectal temperature, oxygen consumption were measured, and metabolic heat production was calculated. A questionnaire was used for a subjective evaluation of comfort, thermal sensation, and shivering. Results Skin temperature was significantly higher 15 minutes after wrapping using Hibler's method compared with wrapping with ambulance blankets / quilts or bubble wrap. There were no differences in core temperature between the three insulating methods. The subjects reported more shivering, they felt colder, were more uncomfortable, and had an increased heat production when using bubble wrap compared with the other two methods. Hibler's method was the volunteers preferred method for preventing hypothermia. Bubble wrap was the least effective insulating method, and seemed to require significantly higher heat production to compensate for increased heat loss. Conclusions This study demonstrated that a combination of vapour tight layer and an additional dry insulating layer (Hibler's method) is the most efficient wrapping method to prevent heat loss, as shown by increased skin temperatures, lower metabolic rate and better thermal comfort. This should then be the method of choice when wrapping a wet patient at risk of developing hypothermia in prehospital environments. PMID:21699720

Estimating Clothing Thermal Insulation Using an Infrared Camera

PubMed Central

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

2016-01-01

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

16 CFR § 1505.8 - Maximum acceptable material temperatures.

Code of Federal Regulations, 2013 CFR

2013-01-01

... heat-resistant properties, or if the insulation meets the thermal requirements. 4 40 less than melting... 105 insulation on windings or relays, solenoids, etc.: Thermocouple method 2 90 194 Resistance method 110 230 Class 130 insulation system 110 230 Insulation: Varnished-cloth insulation 85 185 Fiber used...

Insulator coating for high temperature alloys method for producing insulator coating for high temperature alloys

DOEpatents

Park, J.H.

1998-06-23

A method for fabricating an electrically insulating coating on a surface is disclosed comprising coating the surface with a metal, and reacting the metal coated surface with a nonmetal so as to create a film on the metal-coated surface. Alternatively, the invention provides for a method for producing a noncorrosive, electrically insulating coating on a surface saturated with a nonmetal comprising supplying a molten fluid, dissolving a metal in the molten fluid to create a mixture, and contacting the mixture with the saturated surface. Lastly, the invention provides an electrically insulative coating comprising an underlying structural substrate coated with an oxide or nitride compound. 2 figs.

Minimising mortality in endangered raptors due to power lines: the importance of spatial aggregation to optimize the application of mitigation measures.

PubMed

Guil, Francisco; Fernández-Olalla, Mariana; Moreno-Opo, Rubén; Mosqueda, Ignacio; Gómez, María Elena; Aranda, Antonio; Arredondo, Angel; Guzmán, José; Oria, Javier; González, Luis Mariano; Margalida, Antoni

2011-01-01

Electrocution by power lines is one of the main causes of non-natural mortality in birds of prey. In an area in central Spain, we surveyed 6304 pylons from 333 power lines to determine electrocution rates, environmental and design factors that may influence electrocution and the efficacy of mitigation measures used to minimise electrocution cases. A total of 952 electrocuted raptors, representing 14 different species, were observed. Electrocuted raptors were concentrated in certain areas and the environmental factors associated with increased electrocution events were: greater numbers of prey animals; greater vegetation cover; and shorter distance to roads. The structural elements associated with electrocutions were shorter strings of insulators, one or more phases over the crossarm, cross-shaped design and pylon function. Of the 952 carcasses found, 148 were eagles, including golden eagle (Aquila chrysaetos), Spanish imperial eagle (Aquila adalberti) and Bonelli's eagle (Aquila fasciata). Electrocuted eagles were clustered in smaller areas than other electrocuted raptors. The factors associated with increased eagle electrocution events were: pylons function, shorter strings of insulators, higher slopes surrounding the pylon, and more numerous potential prey animals. Pylons with increased string of insulators had lower raptor electrocution rates than unimproved pylons, although this technique was unsuccessful for eagles. Pylons with cable insulation showed higher electrocution rates than unimproved pylons, both for raptors and eagles, despite this is the most widely used and recommended mitigation measure in several countries. To optimize the application of mitigation measures, our results recommend the substitution of pin-type insulators to suspended ones and elongating the strings of insulators.

Microplasma Ionization of Volatile Organics for Improving Air/Water Monitoring Systems On-Board the International Space Station

NASA Astrophysics Data System (ADS)

Bernier, Matthew C.; Alberici, Rosana M.; Keelor, Joel D.; Dwivedi, Prabha; Zambrzycki, Stephen C.; Wallace, William T.; Gazda, Daniel B.; Limero, Thomas F.; Symonds, Josh M.; Orlando, Thomas M.; Macatangay, Ariel; Fernández, Facundo M.

2016-07-01

Low molecular weight polar organics are commonly observed in spacecraft environments. Increasing concentrations of one or more of these contaminants can negatively impact Environmental Control and Life Support (ECLS) systems and/or the health of crew members, posing potential risks to the success of manned space missions. Ambient plasma ionization mass spectrometry (MS) is finding effective use as part of the analytical methodologies being tested for next-generation space module environmental analysis. However, ambient ionization methods employing atmospheric plasmas typically require relatively high operation voltages and power, thus limiting their applicability in combination with fieldable mass spectrometers. In this work, we investigate the use of a low power microplasma device in the microhollow cathode discharge (MHCD) configuration for the analysis of polar organics encountered in space missions. A metal-insulator-metal (MIM) structure with molybdenum foil disc electrodes and a mica insulator was used to form a 300 μm diameter plasma discharge cavity. We demonstrate the application of these MIM microplasmas as part of a versatile miniature ion source for the analysis of typical volatile contaminants found in the International Space Station (ISS) environment, highlighting their advantages as low cost and simple analytical devices.

Microplasma Ionization of Volatile Organics for Improving Air/Water Monitoring Systems On-Board the International Space Station.

PubMed

Bernier, Matthew C; Alberici, Rosana M; Keelor, Joel D; Dwivedi, Prabha; Zambrzycki, Stephen C; Wallace, William T; Gazda, Daniel B; Limero, Thomas F; Symonds, Josh M; Orlando, Thomas M; Macatangay, Ariel; Fernández, Facundo M

2016-07-01

Low molecular weight polar organics are commonly observed in spacecraft environments. Increasing concentrations of one or more of these contaminants can negatively impact Environmental Control and Life Support (ECLS) systems and/or the health of crew members, posing potential risks to the success of manned space missions. Ambient plasma ionization mass spectrometry (MS) is finding effective use as part of the analytical methodologies being tested for next-generation space module environmental analysis. However, ambient ionization methods employing atmospheric plasmas typically require relatively high operation voltages and power, thus limiting their applicability in combination with fieldable mass spectrometers. In this work, we investigate the use of a low power microplasma device in the microhollow cathode discharge (MHCD) configuration for the analysis of polar organics encountered in space missions. A metal-insulator-metal (MIM) structure with molybdenum foil disc electrodes and a mica insulator was used to form a 300 μm diameter plasma discharge cavity. We demonstrate the application of these MIM microplasmas as part of a versatile miniature ion source for the analysis of typical volatile contaminants found in the International Space Station (ISS) environment, highlighting their advantages as low cost and simple analytical devices. Graphical Abstract ᅟ.

Respiratory function of children in homes insulated with urea formaldehyde foam insulation.

PubMed Central

Norman, G R; Pengelly, L D; Kerigan, A T; Goldsmith, C H

1986-01-01

A study was carried out to assess the respiratory function of children living in homes insulated with urea formaldehyde foam insulation (UFFI). A large data base on the effect of environmental variables on the respiratory function of 3500 children in the Hamilton, Ont., area had been collected from 1978 to 1980. From this data base 29 children who lived in UFFI-insulated homes were identified, and each was matched with 2 controls according to nine variables that had been shown to be strongly predictive of respiratory function. Reported respiratory symptoms and results of pulmonary function testing in the year immediately following installation of UFFI were examined. No significant differences in any variable were found between the subjects and controls. A power calculation indicated that the study had adequate power to detect clinically important changes. The authors conclude that there was no evidence of respiratory problems resulting from UFFI in the sample studied. PMID:3697859

Synthesis, Processing, and Characterization of Inorganic-Organic Hybrid Cross-Linked Silica, Organic Polyimide, and Inorganic Aluminosilicate Aerogels

NASA Technical Reports Server (NTRS)

Nguyen, Baochau N.; Guo, Haiquan N.; McCorkle, Linda S.

2014-01-01

As aerospace applications become ever more demanding, novel insulation materials with lower thermal conductivity, lighter weight and higher use temperature are required to fit the aerospace application needs. Having nanopores and high porosity, aerogels are superior thermal insulators, among other things. The use of silica aerogels in general is quite restricted due to their inherent fragility, hygroscopic nature, and poor mechanical properties, especially in extereme aerospace environments. Our research goal is to develop aerogels with better mechanical and environmental stability for a variety of aeronautic and space applications including space suit insulation for planetary surface missions, insulation for inflatable structures for habitats, inflatable aerodynamic decelerators for entry, descent and landing (EDL) operations, and cryotank insulation for advance space propulsion systems. Different type of aerogels including organic-inorganic polymer reinforced (hybrid) silica-based aerogels, polyimide aerogels and inorganic aluminosilicate aerogels have been developed and examined.

Data transmission element for downhole drilling components

DOEpatents

Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Fox, Joe; Sneddon, Cameron; Briscoe, Michael

2006-01-31

A robust data transmission element for transmitting information between downhole components, such as sections of drill pipe, in the presence of hostile environmental conditions, such as heat, dirt, rocks, mud, fluids, lubricants, and the like. The data transmission element components include a generally U-shaped annular housing, a generally U-shaped magnetically conductive, electrically insulating element such as ferrite, and an insulated conductor. Features on the magnetically conducting, electrically insulating element and the annular housing create a pocket when assembled. The data transmission element is filled with a polymer to retain the components within the annular housing by filling the pocket with the polymer. The polymer can bond with the annular housing and the insulated conductor but preferably not the magnetically conductive, electrically insulating element. A data transmission element is mounted within a recess proximate a mating surface of a downhole drilling component, such as a section of drill pipe.

Ceramics engineering today and tomorrow: Impact on energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korwin, M.L.

1997-12-01

Ceramic engineering has had a profound impact on the development and use of energy. Perhaps nothing has influenced the growth of human society as much as the presence of energy technology. Today, ceramics are incorporated at all levels of the energy discipline, including dams, electric insulators, capacitors, refractories and fiberglass for home insulation. Tomorrow, leaders are going to expect new ways of harnessing, using and conserving clean and abundant energy. Superconductors and nuclear containment vessels are two developing areas of new ceramic applications. With new environmental regulations, the time of passing-on accepted methods of fabrication will come to an end.more » Ceramic engineers of the future will need to better understand the mechanisms of how materials behave. Through continuous research and joint efforts between different ceramic fields, the future of energy and power, and the technology that it will bring, looks most promising.« less

Technology Solutions Case Study: Cladding Attachment Over Thick Exterior Insulating Sheathing

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of wood-framed walls and mass masonry wall assemblies. Insulation on the exterior of the structure has many direct benefits, including better effective R-value from reduced thermal bridging, better condensation resistance, reduced thermal stress on the structure, as well as other commonly associated improvements such as increased airtightness and improved water management. Although the approach has proven effective, there is resistance to its widespread implementation due to a lack of research and understanding of the mechanisms involved in the development of the verticalmore » displacement resistance capacity. In addition, the long-term in-service performance of the system has been questioned due to potential creep effects of the assembly under the sustained dead load of the cladding and effects of varying environmental conditions. In addition, the current International Building Code (IBC) and International Residential Code (IRC) do not have a provision that specifically allows this assembly. In this project, researchers from Building Science Corporation, a Building America team, investigated these issues to better understand the mechanics behind this method of cladding attachment« less

Method of measuring thermal conductivity of high performance insulation

NASA Technical Reports Server (NTRS)

Hyde, E. H.; Russell, L. D.

1968-01-01

Method accurately measures the thermal conductivity of high-performance sheet insulation as a discrete function of temperature. It permits measurements to be made at temperature drops of approximately 10 degrees F across the insulation and ensures measurement accuracy by minimizing longitudinal heat losses in the system.

NUMERICAL ANALYSIS TECHNIQUE USING THE STATISTICAL ENERGY ANALYSIS METHOD CONCERNING THE BLASTING NOISE REDUCTION BY THE SOUND INSULATION DOOR USED IN TUNNEL CONSTRUCTIONS

NASA Astrophysics Data System (ADS)

Ishida, Shigeki; Mori, Atsuo; Shinji, Masato

The main method to reduce the blasting charge noise which occurs in a tunnel under construction is to install the sound insulation door in the tunnel. However, the numerical analysis technique to predict the accurate effect of the transmission loss in the sound insulation door is not established. In this study, we measured the blasting charge noise and the vibration of the sound insulation door in the tunnel with the blasting charge, and performed analysis and modified acoustic feature. In addition, we reproduced the noise reduction effect of the sound insulation door by statistical energy analysis method and confirmed that numerical simulation is possible by this procedure.

Methods of Testing Thermal Insulation and Associated Test Apparatus

NASA Technical Reports Server (NTRS)

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

2004-01-01

The system and method for testing thermal insulation uses a cryostatic insulation tester having a vacuum chamber and a cold mass including a test chamber and upper and lower guard chambers adjacent thereto. The thermal insulation is positioned within the vacuum chamber and adjacent the cold mass. Cryogenic liquid is supplied to the test chamber, upper guard and lower guard to create a first gas layer in an upper portion of the lower guard chamber and a second gas layer in an upper portion of the test chamber. Temperature are sensed within the vacuum chamber to test the thermal insulation.

Dielectrophoresis device and method having insulating ridges for manipulating particles

DOEpatents

Cummings, Eric B [Livermore, CA; Fiechtner, Gregory J [Livermore, CA

2008-03-25

Embodiments of the present invention provide methods and devices for manipulating particles using dielectrophoresis. Insulating ridges and valleys are used to generate a spatially non-uniform electrical field. Particles may be concentrated, separated, or captured during bulk fluid flow in a channel having insulating ridges and valleys.

Insulation Requirements of High-Voltage Power Systems in Future Spacecraft

NASA Technical Reports Server (NTRS)

Qureshi, A. Haq; Dayton, James A., Jr.

1995-01-01

The scope, size, and capability of the nation's space-based activities are limited by the level of electrical power available. Long-term projections show that there will be an increasing demand for electrical power in future spacecraft programs. The level of power that can be generated, conditioned, transmitted, and used will have to be considerably increased to satisfy these needs, and increased power levels will require that transmission voltages also be increased to minimize weight and resistive losses. At these projected voltages, power systems will not operate satisfactorily without the proper electrical insulation. Open or encapsulated power supplies are currently used to keep the volume and weight of space power systems low and to protect them from natural and induced environmental hazards. Circuits with open packaging are free to attain the pressure of the outer environment, whereas encapsulated circuits are imbedded in insulating materials, which are usually solids, but could be liquids or gases. Up to now, solid insulation has usually been chosen for space power systems. If the use of solid insulation is continued, when voltages increase, the amount of insulation for encapsulation also will have to increase. This increased insulation will increase weight and reduce system reliability. Therefore, non-solid insulation media must be examined to satisfy future spacecraft power and voltage demands. In this report, we assess the suitability of liquid, space vacuum, and gas insulation for space power systems.

Evaluation of Less-Flammable Insulation Fluids and Fire-Prevention Guidance for Transformers

NASA Astrophysics Data System (ADS)

Yamagishi, Akira; Sugawa, Osami

This paper concerns the definition and evaluation of less-flammable of insulation fluids for transformers. In particular it focuses on the ISO5660 cone calorimeter method, which is widely used as an evaluation method for the less-flammable of solids, and proposes that such method is also valid for quantitative evaluation of the less-flammable of insulating fluids. Quantifying the combustion characteristics of insulation fluids and analyzing the causes of fires can be said to be the first step toward implementing appropriate safety measures that will render electric utility equipment more fire retardant or fireproof in the future.

75 FR 38007 - Airworthiness Directives; The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-01

... the environmental control system (ECS). This AD results from reports of duct assemblies in the ECS... assemblies in the ECS wrapped with BMS 8-39 polyurethane foam insulation, a material of which the fire... igniting the BMS 8-39 polyurethane foam insulation on the duct assemblies of the ECS, which could propagate...

Using stepped anvils to make even insulation layers in laser-heated diamond-anvil cell samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Du, Zhixue; Gu, Tingting; Dobrosavljevic, Vasilije

Here, we describe a method to make even insulation layers for high-pressure laser-heated diamond-anvil cell samples using stepped anvils. Moreover, the method works for both single-sided and double-sided laser heating using solid or fluid insulation. The stepped anvils are used as matched pairs or paired with a flat culet anvil to make gasket insulation layers and not actually used at high pressures; thus, their longevity is ensured. We also compare the radial temperature gradients and Soret diffusion of iron between self-insulating samples and samples produced with stepped anvils and find that less pronounced Soret diffusion occurs in samples with evenmore » insulation layers produced by stepped anvils.« less

Using stepped anvils to make even insulation layers in laser-heated diamond-anvil cell samples

DOE PAGES

Du, Zhixue; Gu, Tingting; Dobrosavljevic, Vasilije; ...

2015-09-01

Here, we describe a method to make even insulation layers for high-pressure laser-heated diamond-anvil cell samples using stepped anvils. Moreover, the method works for both single-sided and double-sided laser heating using solid or fluid insulation. The stepped anvils are used as matched pairs or paired with a flat culet anvil to make gasket insulation layers and not actually used at high pressures; thus, their longevity is ensured. We also compare the radial temperature gradients and Soret diffusion of iron between self-insulating samples and samples produced with stepped anvils and find that less pronounced Soret diffusion occurs in samples with evenmore » insulation layers produced by stepped anvils.« less

Determining localized garment insulation values from manikin studies: computational method and results.

PubMed

Nelson, D A; Curlee, J S; Curran, A R; Ziriax, J M; Mason, P A

2005-12-01

The localized thermal insulation value expresses a garment's thermal resistance over the region which is covered by the garment, rather than over the entire surface of a subject or manikin. The determination of localized garment insulation values is critical to the development of high-resolution models of sensible heat exchange. A method is presented for determining and validating localized garment insulation values, based on whole-body insulation values (clo units) and using computer-aided design and thermal analysis software. Localized insulation values are presented for a catalog consisting of 106 garments and verified using computer-generated models. The values presented are suitable for use on volume element-based or surface element-based models of heat transfer involving clothed subjects.

[Preventive effects of sound insulation windows on the indoor noise levels in a street residential building in Beijing].

PubMed

Guo, Bin; Huang, Jing; Guo, Xin-biao

2015-06-18

To evaluate the preventive effects of sound insulation windows on traffic noise. Indoor noise levels of the residential rooms (on both the North 4th ring road side and the campus side) with closed sound insulation windows were measured using the sound level meter, and comparisons with the simultaneously measured outdoor noise levels were made. In addition, differences of indoor noise levels between rooms with closed sound insulation windows and open sound insulation windows were also compared. The average outdoor noise levels of the North 4th ring road was higher than 70 dB(A), which exceeded the limitation stated in the "Environmental Quality Standard for Noise" (GB 3096-2008) in our country. However, with the sound insulation windows closed, the indoor noise levels reduced significantly to the level under 35 dB(A) (P<0.05), which complied with the indoor noise level standards in our country. The closed or open states of the sound insulation windows had significant influence on the indoor noise levels (P<0.05). Compared with the open state of the sound insulation window, when the sound insulation windows were closed, the indoor noise levels reduced 18.8 dB(A) and 8.3 dB(A) in residential rooms facing North 4th ring road side and campus side, respectively. The results indicated that installation of insulation windows had significant noise reduction effects on street residential buildings especially on the rooms facing major traffic roads. Installation of the sound insulation windows has significant preventive effects on indoor noise in the street residential building.

Minimising Mortality in Endangered Raptors Due to Power Lines: The Importance of Spatial Aggregation to Optimize the Application of Mitigation Measures

PubMed Central

Guil, Francisco; Fernández-Olalla, Mariana; Moreno-Opo, Rubén; Mosqueda, Ignacio; Gómez, María Elena; Aranda, Antonio; Arredondo, Ángel; Guzmán, José; Oria, Javier; González, Luis Mariano; Margalida, Antoni

2011-01-01

Electrocution by power lines is one of the main causes of non-natural mortality in birds of prey. In an area in central Spain, we surveyed 6304 pylons from 333 power lines to determine electrocution rates, environmental and design factors that may influence electrocution and the efficacy of mitigation measures used to minimise electrocution cases. A total of 952 electrocuted raptors, representing 14 different species, were observed. Electrocuted raptors were concentrated in certain areas and the environmental factors associated with increased electrocution events were: greater numbers of prey animals; greater vegetation cover; and shorter distance to roads. The structural elements associated with electrocutions were shorter strings of insulators, one or more phases over the crossarm, cross-shaped design and pylon function. Of the 952 carcasses found, 148 were eagles, including golden eagle (Aquila chrysaetos), Spanish imperial eagle (Aquila adalberti) and Bonelli's eagle (Aquila fasciata). Electrocuted eagles were clustered in smaller areas than other electrocuted raptors. The factors associated with increased eagle electrocution events were: pylons function, shorter strings of insulators, higher slopes surrounding the pylon, and more numerous potential prey animals. Pylons with increased string of insulators had lower raptor electrocution rates than unimproved pylons, although this technique was unsuccessful for eagles. Pylons with cable insulation showed higher electrocution rates than unimproved pylons, both for raptors and eagles, despite this is the most widely used and recommended mitigation measure in several countries. To optimize the application of mitigation measures, our results recommend the substitution of pin-type insulators to suspended ones and elongating the strings of insulators. PMID:22140549

Ceramic fiber insulation impregnated with an infra-red retardant coating and method for production thereof

NASA Technical Reports Server (NTRS)

Zinn, Alfred A. (Inventor); Tarkanian, Ryan Jeffrey (Inventor)

2007-01-01

The invented insulation is a ceramic fiber insulation wherein the ceramic fibers are treated with a coating which contains transition metal oxides. The invented process for coating the insulation is a process of applying the transition metal oxide coating to the fibers of the insulation after the fibers have been formed into a tile or other porous body. The coating of transition metal oxide lowers the transmittance of radiation through the insulation thereby lowering the temperature of the backface of the insulation and better protecting the structure that underlies the insulation.

Study on electrochemical corrosion mechanism of steel foot of insulators for HVDC lines

NASA Astrophysics Data System (ADS)

Zheng, Weihua; Sun, Xiaoyu; Fan, Youping

2017-09-01

The main content of this paper is the mechanism of electrochemical corrosion of insulator steel foot in HVDC transmission line, and summarizes five commonly used artificial electrochemical corrosion accelerated test methods in the world. Various methods are analyzed and compared, and the simulation test of electrochemical corrosion of insulator steel feet is carried out by water jet method. The experimental results show that the experimental environment simulated by water jet method is close to the real environment. And the three suspension modes of insulators in the actual operation, the most serious corrosion of the V type suspension hardware, followed by the tension string suspension, and the linear string corrosion rate is the slowest.

A Cs(x)WO3/ZnO nanocomposite as a smart coating for photocatalytic environmental cleanup and heat insulation.

PubMed

Wu, Xiaoyong; Yin, Shu; Xue, Dongfeng; Komarneni, Sridhar; Sato, Tsugio

2015-10-28

A novel CsxWO3/ZnO smart coating was proposed to achieve multiple functions, such as heat insulation, photodecomposition of toxic NO gas, blocking of harmful UV light, etc. In this composite coating, CsxWO3 nanorods were used as a NIR and UV light shielding material while ZnO nanoparticles were utilized as a photocatalyst and a material to enhance visible light transmittance and block UV light. When the mass ratio of CsxWO3/ZnO was 1, the composite coating possessed a very good visible light transmittance of over 80% and an excellent UV-shielding ability. This novel coating showed heat insulation that is superior to the ITO coating and photocatalytic decontamination of NO gas that is superior to the standard TiO2 (P25). The proposed CsxWO3/ZnO smart coating is a promising material not only for energy saving but also for environmental cleanup.

Recycled blocks with improved sound and fire insulation containing construction and demolition waste.

PubMed

Leiva, Carlos; Solís-Guzmán, Jaime; Marrero, Madelyn; García Arenas, Celia

2013-03-01

The environmental problem posed by construction and demolition waste (C&D waste) is derived not only from the high volume produced, but also from its treatment and disposal. Treatment plants receive C&D waste which is then transformed into a recycled mixed aggregate. The byproduct is mainly used for low-value-added applications such as land escape restoration, despite the high quality of the aggregate. In the present work, the chemical composition properties and grading curve properties of these aggregates are defined. Furthermore, the resulting recycled concrete with a high proportion of recycled composition, from 20% to 100% replacement of fine and coarse aggregate, is characterized physically and mechanically. An environmental study of the new construction material when all aggregates are substituted by C&D waste shows a low toxicity level, similar to that of other construction materials. The new material also has improved properties with respect to standard concrete such as high fire resistance, good heat insulation, and acoustic insulation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Assessment of Eco-friendly Gases for Electrical Insulation to Replace the Most Potent Industrial Greenhouse Gas SF6.

PubMed

Rabie, Mohamed; Franck, Christian M

2018-01-16

Gases for electrical insulation are essential for the operation of electric power equipment. This Review gives a brief history of gaseous insulation that involved the emergence of the most potent industrial greenhouse gas known today, namely sulfur hexafluoride. SF 6 paved the way to space-saving equipment for the transmission and distribution of electrical energy. Its ever-rising usage in the electrical grid also played a decisive role in the continuous increase of atmospheric SF 6 abundance over the last decades. This Review broadly covers the environmental concerns related to SF 6 emissions and assesses the latest generation of eco-friendly replacement gases. They offer great potential for reducing greenhouse gas emissions from electrical equipment but at the same time involve technical trade-offs. The rumors of one or the other being superior seem premature, in particular because of the lack of dielectric, environmental, and chemical information for these relatively novel compounds and their dissociation products during operation.

Health impacts due to personal exposure to fine particles caused by insulation of residential buildings in Europe

NASA Astrophysics Data System (ADS)

Gens, Alexandra; Hurley, J. Fintan; Tuomisto, Jouni T.; Friedrich, Rainer

2014-02-01

The insulation of residential buildings affects human exposure to fine particles. According to current EU guidelines, insulation is regulated for energy saving reasons. As buildings become tighter, the air exchange rate is reduced and, thus, the indoor concentration of pollutants is increased if there are significant indoor sources. While usually the effects of heat insulation and increase of the air-tightness of buildings on greenhouse gas emissions are highlighted, the negative impacts on human health due to higher indoor concentrations are not addressed. Thus, we investigated these impacts using scenarios in three European countries, i. e. Czech Republic, Switzerland and Greece. The assessment was based on modelling the human exposure to fine particles originating from sources of particles within outdoor and indoor air, including environmental tobacco smoke. Exposure response relationships were derived to link (adverse) health effects to the exposure. Furthermore, probable values for the parameters influencing the infiltration of fine particles into residential buildings were modelled. Results show that the insulation and increase of the air-tightness of residential buildings leads to an overall increase of the mean population exposure - and consequently adverse health effects - in all considered countries (ranging for health effects from 0.4% in Czech Republic to 11.8% in Greece for 100% insulated buildings) due to an accumulation of particles indoors, especially from environmental tobacco smoke. Considering only the emission reductions in outdoor air (omitting changes in infiltration parameters) leads to a decrease of adverse health effects. This study highlights the importance of ensuring a sufficient air exchange rate when insulating buildings, e. g. by prescribing heat ventilation and air conditioning systems in new buildings and information campaigns on good airing practice in renovated buildings. It also shows that assessing policy measures based on the exposure may provide different recommendations compared to an assessment based on only the outdoor air concentration.

Method of preventing leakage of a fluid along and through an insulating jacket of a thermocouple

DOEpatents

Thermos, Anthony Constantine; Rahal, Fadi Elias

2002-01-01

A thermocouple assembly includes a thermocouple; a plurality of lead wires extending from the thermocouple; an insulating jacket extending along and enclosing the plurality of leads; and at least one internally sealed area within the insulating jacket to prevent fluid leakage along and within the insulating jacket. The invention also provides a method of preventing leakage of a fluid along and through an insulating jacket of a thermocouple including the steps of a) attaching a plurality of lead wires to a thermocouple; b) adding a heat sensitive pseudo-wire to extend along the plurality of lead wires; c) enclosing the lead wires and pseudo-wire inside an insulating jacket; d) locally heating axially spaced portions of the insulating jacket to a temperature which melts the pseudo-wire and fuses it with an interior surface of the jacket.

Explosion resistant insulator and method of making same

DOEpatents

Meyer, Jeffry R.; Billings, Jr., John S.; Spindle, Harvey E.; Hofmann, Charles F.

1983-01-01

An electrical insulator assembly and method of manufacturing same, having a generally cylindrical or conical body portion formed of a breakable cast solid insulation system and a reinforcing member having a corrugated configuration and formed of a web or mesh type reinforcing fabric. When the breakable body member has been broken, the corrugated configured reinforcing web member provides a path of escape for pressurized insulating fluid while limiting the movement of body member fragments in the direction of escape of the pressurized fluid.

Evaluation of Test Methods To Determine the Impact Resistance of Exterior Insulation and Finish Systems (EIFS).

DTIC Science & Technology

1992-07-01

be used effectively in new construction or retrofit applications. These systems usually contain: 1. Molded expanded polystyrene insulation board (MEPS...commonly referred to as "bead board," or extruded expanded polystyrene insulation board (XEPS), commonly referred to as "blue board." 2. An...Walls ( Expanded Polystyrene Insulation Faced with a Thin Rendering), M.O.A.T. n 22, June 1988. 7 ASTM D3029-90. "Standard Test Methods for Impact

KSC-2009-6795

NASA Image and Video Library

2009-12-11

CAPE CANAVERAL, Fla. - Concrete covers the insulation in the walls for the Propellants North Administrative and Maintenance Facility in Launch Complex 39 at NASA's Kennedy Space Center in Florida. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2009-6801

NASA Image and Video Library

2009-12-11

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, the walls for the Propellants North Administrative and Maintenance Facility get a layer of high-density foam insulation. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2009-6800

NASA Image and Video Library

2009-12-11

CAPE CANAVERAL, Fla. - Insulation is placed in the walls for the Propellants North Administrative and Maintenance Facility in Launch Complex 39 at NASA's Kennedy Space Center in Florida. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2009-6793

NASA Image and Video Library

2009-12-11

CAPE CANAVERAL, Fla. - Concrete is poured over the insulation in the walls for the Propellants North Administrative and Maintenance Facility in Launch Complex 39 at NASA's Kennedy Space Center in Florida. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

Method and apparatus for fabrication of high gradient insulators with parallel surface conductors spaced less than one millimeter apart

DOEpatents

Sanders, David M.; Decker, Derek E.

1999-01-01

Optical patterns and lithographic techniques are used as part of a process to embed parallel and evenly spaced conductors in the non-planar surfaces of an insulator to produce high gradient insulators. The approach extends the size that high gradient insulating structures can be fabricated as well as improves the performance of those insulators by reducing the scale of the alternating parallel lines of insulator and conductor along the surface. This fabrication approach also substantially decreases the cost required to produce high gradient insulators.

Fault location method for unexposed gas trunk line insulation at stray current constant effect area

NASA Astrophysics Data System (ADS)

Tsenev, A. N.; Nosov, V. V.; Akimova, E. V.

2017-10-01

For the purpose of gas trunk lines safe operation, two types of pipe wall metal anticorrosion protection are generally used - the passive (insulation coating) protection and the active (electrochemical) protection. In the process of a pipeline long-term operation, its insulation is subject to wear and damage. Electrochemical protection means of a certain potential value prevent metal dissolution in the soil. When insulation wear and tear attains a level of insufficiency of the protection potential value, the insulating coating needs repair which is a labor-consuming procedure. To reduce the risk of such situation, it is necessary to make inspection rounds to monitor the condition of pipe insulation. A method for pipeline insulation coating unexposed fault location based on Pearson method is considered, wherein a working cathodic protection station signal of 100 Hz frequency is used, which makes installation of a generator unnecessary, and also a specific generator signal of 1 kHz frequency is used at high noise immunity and sensitivity of the instrument complex. This method enables detection and sizing of unexposed pipeline defects within the zones of earth current permanent action. High noise immunity of selective indicators allows for operation in proximity to 110 kV, 220 kV, and 500 kV power transmission lines in action.

ETV REPORT AND STATEMENT, ABB INC. BIOTEMP VETABLE OIL - BASED INSULATING DIELECTRIC FLUID

EPA Science Inventory

THE USEPA has created the ETV program to facilitate the deployment of innovative of improved environmental technologies through performance verification and information dissemination. The goal of the ETV Program is to further environmental protection by substantially acceleratin...

Thick film magnetic nanoparticulate composites and method of manufacture thereof

NASA Technical Reports Server (NTRS)

Ge, Shihui (Inventor); Yan, Dajing (Inventor); Xiao, Danny T. (Inventor); Ma, Xinqing (Inventor); Zhang, Yide (Inventor); Zhang, Zongtao (Inventor)

2009-01-01

Thick film magnetic/insulating nanocomposite materials, with significantly reduced core loss, and their manufacture are described. The insulator coated magnetic nanocomposite comprises one or more magnetic components, and an insulating component. The magnetic component comprises nanometer scale particles (about 1 to about 100 nanometers) coated by a thin-layered insulating phase. While the intergrain interaction between the immediate neighboring magnetic nanoparticles separated by the insulating phase provides the desired soft magnetic properties, the insulating material provides high resistivity, which reduces eddy current loss.

The relationship between environmental temperature and clothing insulation across a year

NASA Astrophysics Data System (ADS)

Kwon, JuYoun; Choi, Jeongwha

2012-09-01

People adapt to thermal environments, such as the changing seasons, predominantly by controlling the amount of clothing insulation, usually in the form of the clothing that they wear. The aim of this study was to determine the actual daily clothing insulation on sedentary human subjects across the seasons. Thirteen females and seven males participated in experiments from January to December in a thermal chamber. Adjacent months were grouped in pairs to give six environmental conditions: (1) January/February = 5°C; (2) March/April = 14°C; (3) May/June = 25°C; (4) July/August = 29°C; (5) September/October = 23°C; (6) November/December = 8°C. Humidity(45 ± 5%) and air velocity(0.14 ± 0.01 m/s) were constant across all six experimental conditions. Participants put on their own clothing that allowed them to achieve thermal comfort for each air temperature, and sat for 60 min (1Met). The clothing insulation (clo) required by these participants had a significant relationship with air temperature: insulation was reduced as air temperature increased. The range of clothing insulation for each condition was 1.87-3.14 clo at 5°C(Jan/Feb), 1.62-2.63 clo at 14°C(Mar/Apr), 0.87-1.59 clo at 25°C(May/Jun), 0.4-1.01 clo at 29°C(Jul/Aug), 0.92-1.81 clo at 23°C (Sept/Oct), and 2.12-3.09 clo at 8°C(Nov/Dec) for females, and 1.84-2.90 clo at 5°C, 1.52-1.98 clo at 14°C, 1.04-1.23 clo at 25°C, 0.51-1.30 clo at 29°C, 0.82-1.45 clo at 23°C and 1.96-3.53 clo at 8°C for males. The hypothesis was that thermal insulation of free living clothing worn by sedentary Korean people would vary across seasons. For Korean people, a comfortable air temperature with clothing insulation of 1 clo was approximately 27°C. This is greater than the typical comfort temperature for 1 clo. It was also found that women clearly increased their clothing insulation level of their clothing as winter approached but did not decrease it by the same amount when spring came.

Making Insulation Decisions through Mathematical Modeling

ERIC Educational Resources Information Center

Yanik, H. Bahadir; Memis, Yasin

2014-01-01

Engaging students in studies about conservation and sustainability can support their understanding of making environmental conscious decisions to conserve Earth. This article aims to contribute these efforts and direct students' attention to how they can use mathematics to make environmental decisions. Contributors to iSTEM: Integrating…

Repairing Damaged Power-Cable Insulation

NASA Technical Reports Server (NTRS)

Baker, G. E.

1984-01-01

Simple method saves time, money, and material. In new method cable remains in place while new insulation is applied to damaged portion. Method results in new terminations with safety factor equal to that of any portion of cable.

The relationship between thermal environments and clothing insulation for elderly individuals in Shanghai, China.

PubMed

Jiao, Yu; Yu, Hang; Wang, Tian; An, Yusong; Yu, Yifan

2017-12-01

The relationship between thermal environmental parameters and clothing insulation is an important element in improving thermal comfort for the elderly. A field study was conducted on the indoor, transition space, and outdoor thermal environments of 17 elderly facilities in Shanghai, China. A random questionnaire survey was used to gather data from 672 valid samples. A statistical analysis of the data was conducted, and multiple linear regression models were established to quantify the relationships between clothing insulation, respondent age, indoor air temperature, and indoor relative humidity. Results indicated that the average thermal insulation of winter and summer clothing is 1.38 clo and 0.44 clo, respectively, for elderly men and 1.39 clo and 0.45 clo, respectively, for elderly women. It was also found that the thermal insulation of winter clothing is linearly correlated with age, and that there were seasonal differences in the relationship between clothing insulation and the environment. During winter, the clothing insulation is negatively correlated only with indoor temperature parameters (air temperature and operative temperature) for elderly males, while it is negatively correlated with indoor temperature parameters as well as transition space and outdoor air temperature for elderly females. In summer, clothing insulation for both elderly males and females is negatively correlated with outdoor temperature, as well as indoor temperature parameters (air temperature and operative temperature). The thermal insulation of summer clothing is also negatively correlated with transitional space temperature for males. Copyright © 2017 Elsevier Ltd. All rights reserved.

A water blown urethane insulation for use in cryogenic environments

NASA Technical Reports Server (NTRS)

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.

Heat insulating device for low temperature liquefied gas storage tank

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okamoto, T.; Nishimoto, T.; Sawada, K.

1978-05-02

Hitachi Shipbuilding and Engineering Co., Ltd.'s insulation method for spherical LNG containers solves various problems associated with insulating a sphere's three-dimensional curved surface; equalizing the thickness of the insulation, insulating the junctions between insulation blocks, and preventing seawater or LNG from penetrating the insulation barrier in the event of a rupture in the tank and ship's hull. The design incorporates a number of blocks or plates of rigid foam-insulating material bonded to the outer wall; seats for receiving pressing jigs for the bonding operation are secured to the outer wall in the joints between the insulating blocks. The joints aremore » filled with soft synthetic foam (embedding the seats), a moistureproof layer covers the insulating blocks and joints, and a waterproof material covers the moistureproof layer.« less

Insulated laser tube structure and method of making same

DOEpatents

Dittbenner, Gerald R.

1999-01-01

An insulated high temperature ceramic laser tube having substantially uniform insulation along the length of the tube is disclosed having particulate ceramic insulation positioned between the outer wall of the ceramic laser tube and the inner surface of tubular ceramic fiber insulation which surrounds the ceramic laser tube. The particulate ceramic insulation is preferably a ceramic capable of sintering to the outer surface of the ceramic laser tube and to the inner surface of the tubular ceramic fiber insulation. The addition of the particulate ceramic insulation to fill all the voids between the ceramic laser tube and the fibrous ceramic insulation permits the laser tube to be operated at a substantially uniform temperature throughout the length of the laser tube.

Insulation board and process of making

DOEpatents

Nowobilski, Jeffert J.; Owens, William J.

1985-01-01

Insulation board capable of bearing a load without significant loss of insulating capacity due to compression, produced by a method wherein the board is made in compliance with specified conditions of time, temperature and pressure.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schumacher, C. J.; Fox, M. J.; Lstiburek, J.

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.

Perioperative thermal insulation.

PubMed

Bräuer, Anselm; Perl, Thorsten; English, Michael J M; Quintel, Michael

2007-01-01

Perioperative hypothermia remains a common problem during anesthesia and surgery. Unfortunately, the implementation of new minimally invasive surgical procedures has not lead to a reduction of this problem. Heat losses from the skin can be reduced by thermal insulation to avoid perioperative hypothermia. However, only a small amount of information is available regarding the physical properties of insulating materials used in the Operating Room (OR). Therefore, several materials using validated manikins were tested. Heat loss from the surface of the manikin can be described as:"Q = h . DeltaT . A" where Q = heat flux, h = heat exchange coefficient, DeltaT = temperature gradient between the environment and surface, and A = covered area. Heat flux per unit area and surface temperature were measured with calibrated heat flux transducers. Environmental temperature was measured using a thermoanemometer. The temperature gradient between the surface and environment (DeltaT) was varied and "h" was determined by linear regression analysis as the slope of "DeltaT" versus heat flux per unit area. The reciprocal of the heat exchange coefficient defines the insulation. The insulation values of the materials varied between 0.01 Clo (plastic bag) to 2.79 Clo (2 layers of a hospital duvet). Given the range of insulating materials available for outdoor activities, significant improvement in insulation of patients in the OR is both possible and desirable.

DC partial discharge/environmental test screening of space TWTS

NASA Astrophysics Data System (ADS)

Hai, F.; Paschen, K. W.

Direct-current partial discharge/environmental tests are being conducted on traveling wave tubes (TWTs) designated for long-term space operation to screen out tubes with high voltage defects. Two types of TWTs with different external high-voltage insulation are being examined: (1) TWTs with polymeric potting, and (2) TWTs with ceramic feedthroughs. Detection of high voltage defects in the form of cracks and seprations in potted systems is enhanced by combining dc partial discharge testing with environmental (temperature and pressure) testing. These defects are usually caused by high stresses in the potting produced during temperature excursions by the difference in thermal expansion between the potting material and the confining ceramic-metal structure. Tests of all-ceramic-insulated TWTs indicate that the high voltage problem is internal to the vacuum envelope and requires both leakage and discharge measurements for diagnosis. This problem appears to be field emission from contaminated surfaces.

Overview (this manuscript is an overview of an ASTM ...

EPA Pesticide Factsheets

The Symposium on Developing Consensus Standards for Measuring Chemical Emissions from Spray Polyurethane Foam (SPF) Insulation was held on April 30th and May 1, 2015. Sponsored by ASTM Committee D22 on Air Quality, the symposium was held in Anaheim, CA, in conjunction with the standards development meetings of the Committee. ASTM D22.05 is developing tools to answer fundamental questions: what is emitted from SPF, how long do the emissions persist, how does ventilation impact concentrations and potential exposures? How can we model these processes to address the multiplicity of products, applications, and environmental conditions that may impact exposure to emissions over the life cycle of the material? These are complex and interrelated questions that have challenged the indoor environments research community for many years. Objectives of Symposium: Standardized methods are needed to assess the potential impacts of SPF insulation products on indoor air quality, establish re-entry times for trade workers or re-occupancy times for building occupants after product installation and to evaluate post-occupancy ventilation. The objective of the symposium was to provide a forum for the exchange of ideas from SPF manufacturers, regulatory agencies, indoor air quality professionals, testing labs, air quality consultants, instrument vendors and other stakeholders. Following the presentations on the current status of measuring emissions from SPF insulation, participants di

Thermal Performance Testing of Cryogenic Insulation Systems

NASA Technical Reports Server (NTRS)

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

2007-01-01

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

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

NASA Astrophysics Data System (ADS)

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.

Humidity effects on wire insulation breakdown strength.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Appelhans, Leah

2013-08-01

Methods for the testing of the dielectric breakdown strength of insulation on metal wires under variable humidity conditions were developed. Two methods, an ASTM method and the twisted pair method, were compared to determine if the twisted pair method could be used for determination of breakdown strength under variable humidity conditions. It was concluded that, although there were small differences in outcomes between the two testing methods, the non-standard method (twisted pair) would be appropriate to use for further testing of the effects of humidity on breakdown performance. The dielectric breakdown strength of 34G copper wire insulated with double layermore » Poly-Thermaleze/Polyamide-imide insulation was measured using the twisted pair method under a variety of relative humidity (RH) conditions and exposure times. Humidity at 50% RH and below was not found to affect the dielectric breakdown strength. At 80% RH the dielectric breakdown strength was significantly diminished. No effect for exposure time up to 140 hours was observed at 50 or 80%RH.« less

Optimization of Refining Craft for Vegetable Insulating Oil

NASA Astrophysics Data System (ADS)

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.

Imaging of β-cell mass and insulitis in insulin-dependent (Type 1) diabetes mellitus.

PubMed

Di Gialleonardo, Valentina; de Vries, Erik F J; Di Girolamo, Marco; Quintero, Ana M; Dierckx, Rudi A J O; Signore, Alberto

2012-12-01

Insulin-dependent (type 1) diabetes mellitus is a metabolic disease with a complex multifactorial etiology and a poorly understood pathogenesis. Genetic and environmental factors cause an autoimmune reaction against pancreatic β-cells, called insulitis, confirmed in pancreatic samples obtained at autopsy. The possibility to noninvasively quantify β-cell mass in vivo would provide important biological insights and facilitate aspects of diagnosis and therapy, including follow-up of islet cell transplantation. Moreover, the availability of a noninvasive tool to quantify the extent and severity of pancreatic insulitis could be useful for understanding the natural history of human insulin-dependent (type 1) diabetes mellitus, to early diagnose children at risk to develop overt diabetes, and to select patients to be treated with immunotherapies aimed at blocking the insulitis and monitoring the efficacy of these therapies. In this review, we outline the imaging techniques currently available for in vivo, noninvasive detection of β-cell mass and insulitis. These imaging techniques include magnetic resonance imaging, ultrasound, computed tomography, bioluminescence and fluorescence imaging, and the nuclear medicine techniques positron emission tomography and single-photon emission computed tomography. Several approaches and radiopharmaceuticals for imaging β-cells and lymphocytic insulitis are reviewed in detail.

Optimization by means of an analytical heat transfer model of a thermal insulation for CSP applications based on radiative shields

NASA Astrophysics Data System (ADS)

Gaetano, A.; Roncolato, J.; Montorfano, D.; Barbato, M. C.; Ambrosetti, G.; Pedretti, A.

2016-05-01

The employment of new gaseous heat transfer fluids as air or CO2, which are cheaper and environmentally friendly, is drawing more and more attention within the field of Concentrated Solar Power applications. However, despite the advantages, their use requires receivers with a larger heat transfer area and flow cross section with a consequent greater volume of thermal insulation. Solid thermal insulations currently used present high thermal inertia which is energetically penalizing during the daily transient phases faced by the main plant components (e.g. receivers). With the aim of overcoming this drawback a thermal insulation based on radiative shields is presented in this study. Starting from an initial layout comprising a solid thermal insulation layer, the geometry was optimized avoiding the use of the solid insulation keeping performance and fulfilling the geometrical constraints. An analytical Matlab model was implemented to assess the system thermal behavior in terms of heat loss taking into account conductive, convective and radiative contributions. Accurate 2D Computational Fluid Dynamics (CFD) simulations were run to validate the Matlab model which was then used to select the most promising among three new different designs.

Analysis and Testing of High Temperature Fibrous Insulation for Reusable Launch Vehicles

NASA Technical Reports Server (NTRS)

Daryabeigi, Kamran

1999-01-01

Analytical models were developed to model the heat transfer through high-temperature fibrous insulation used in metallic thermal protection systems on reusable launch vehicles. The optically thick approximation was used to simulate radiation heat transfer through the insulation. Different models for gaseous conduction and solid conduction in the fibers, and for combining the various modes of heat transfer into a local, volume-averaged, thermal conductivity were considered. The governing heat transfer equations were solved numerically, and effective thermal conductivities were calculated from the steady-state results. An experimental apparatus was developed to measure the apparent thermal conductivity of insulation subjected to pressures, temperatures and temperature gradients representative of re-entry conditions for launch vehicles. The apparent thermal conductivity of an alumina fiber insulation was measured at nominal densities of 24, 48 and 96 kg/cu m. Data were obtained at environmental pressures from 10(exp 4) to 760 torr, with the insulation cold side maintained at room temperature and its hot side temperature varying up to 1000 C. The experimental results were used to evaluate the analytical models. The best analytical model resulted in effective thermal conductivity predictions that were within 8% of experimental results.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schumacher, C. J.; Fox, M. J.; Lstiburek, J.

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.

Optimum insulation thickness in wood-framed homes.

Treesearch

A.E. Oviatt

1975-01-01

New design methods must be developed to reduce energy waste in buildings. This study examines an economic approach to the design of thermal insulation in the home and demonstrates graphically that an optimum point of insulation thickness occurs where total costs of insulation and energy over the useful life of a building are a minimum. The optimum thickness thus...

Micro-fabricated integrated coil and magnetic circuit and method of manufacturing thereof

DOEpatents

Mihailovich, Robert E.; Papavasiliou, Alex P.; Mehrotra, Vivek; Stupar, Philip A.; Borwick, III, Robert L.; Ganguli, Rahul; DeNatale, Jeffrey F.

2017-03-28

A micro-fabricated electromagnetic device is provided for on-circuit integration. The electromagnetic device includes a core. The core has a plurality of electrically insulating layers positioned alternatingly between a plurality of magnetic layers to collectively form a continuous laminate having alternating magnetic and electrically insulating layers. The electromagnetic device includes a coil embedded in openings of the semiconductor substrate. An insulating material is positioned in the cavity and between the coil and an inner surface of the core. A method of manufacturing the electromagnetic device includes providing a semiconductor substrate having openings formed therein. Windings of a coil are electroplated and embedded in the openings. The insulating material is coated on or around an exposed surface of the coil. Alternating magnetic layers and electrically insulating layers may be micro-fabricated and electroplated as a single and substantially continuous segment on or around the insulating material.

Thermal performance of gaseous-helium-purged tank-mounted multilayer insulation system during ground-hold and space-hold thermal cycling and exposure to water vapor

NASA Technical Reports Server (NTRS)

Sumner, I. E.

1978-01-01

An experimental investigation was conducted to determine (1) the ground-hold and space-hold thermal performance of a multilayer insulation (MLI) system mounted on a spherical, liquid-hydrogen propellant tank and (2) the degradation to the space-hold thermal performance of the insulation system that resulted from both thermal cycling and exposure to moisture. The propellant tank had a diameter of 1.39 meters (4.57ft). The MLI consisted of two blankets of insulation; each blanket contained 15 double-aluminized Mylar radiation shields separated by double silk net spacers. Nineteen tests simulating basic cryogenic spacecraft thermal (environmental) conditions were conducted. These tests typically included initial helium purge, liquid-hydrogen fill and ground-hold, ascent, space-hold, and repressurization. No significant degradation of the space-hold thermal performance due to thermal cycling was noted.

Insulation Test Cryostat with Lift Mechanism

NASA Technical Reports Server (NTRS)

Dokos, Adam G. (Inventor); Fesmire, James E. (Inventor)

2014-01-01

A multi-purpose, cylindrical thermal insulation test apparatus is used for testing insulation materials and systems of materials using a liquid boil-off calorimeter system for absolute measurement of the effective thermal conductivity (k-value) and heat flux of a specimen material at a fixed environmental condition (cold-side temperature, warm-side temperature, vacuum pressure level, and residual gas composition). The apparatus includes an inner vessel for receiving a liquid with a normal boiling point below ambient temperature, such as liquid nitrogen, enclosed within a vacuum chamber. A cold mass assembly, including the upper and lower guard chambers and a middle test vessel, is suspended from a lid of the vacuum canister. Each of the three chambers is filled and vented through a single feedthrough. All fluid and instrumentation feedthroughs are mounted and suspended from a top domed lid to allow easy removal of the cold mass. A lift mechanism allows manipulation of the cold mass assembly and insulation test article.

Partial Insulation of Aerated Concrete Wall in its Thermal Bridge Regions

NASA Astrophysics Data System (ADS)

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

2018-01-01

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

Insulation Test Cryostat with Lift Mechanism

NASA Technical Reports Server (NTRS)

Fesmire, James E. (Inventor); Dokos, Adam G. (Inventor)

2016-01-01

A multi-purpose, cylindrical thermal insulation test apparatus is used for testing insulation materials and systems of materials using a liquid boil-off calorimeter system for absolute measurement of the effective thermal conductivity (k-value) and heat flux of a specimen material at a fixed environmental condition (cold-side temperature, warm-side temperature, vacuum pressure level, and residual gas composition). An inner vessel receives liquid with a normal boiling point below ambient temperature, such as liquid nitrogen, enclosed within a vacuum chamber. A cold mass assembly, including upper and lower guard chambers and middle test vessel, is suspended from a lid of the vacuum canister. Each of the three chambers is filled and vented through a single feedthrough. All fluid and instrumentation feedthroughs are mounted and suspended from a top domed lid allowing easy removal of the cold mass. A lift mechanism allows manipulation of the cold mass assembly and insulation test article.

Insulation detection of electric vehicle batteries

NASA Astrophysics Data System (ADS)

Dai, Qiqi; Zhu, Zhongwen; Huang, Denggao; Du, Mingxing; Wei, Kexin

2018-06-01

In this paper, an electric vehicle insulation detection method with single side switching fixed resistance is designed, and the hardware and software design of the system are given. The experiment proves that the insulation detection system can detect the insulation resistance in a wide range of resistance values, and accurately report the fault level. This system can effectively monitor the insulation fault between the car body and the high voltage line and avoid the passengers from being injured.

Development of an external ceramic insulation for the space shuttle orbiter. Part 2: Optimization

NASA Technical Reports Server (NTRS)

Tanzilli, R. A. (Editor)

1973-01-01

The basic insulation improvement study concentrated upon evaluating variables which could result in significant near-term gains in mechanical behavior and insulation effectiveness of the baseline system. The approaches undertaken included: evaluation of small diameter fibers, optimization of binder: slurry characteristics, evaluation of techniques for controlling fiber orientation, optimization of firing cycle, and the evaluation of methods for improving insulation efficiency. A detailed discussion of these basic insulation improvement studies is presented.

Designing Predictive Diagnose Method for Insulation Resistance Degradation of the Electrical Power Cables from Neutral Insulated Power Networks

NASA Astrophysics Data System (ADS)

Dobra, R.; Pasculescu, D.; Risteiu, M.; Buica, G.; Jevremović, V.

2017-06-01

This paper describe some possibilities to minimize voltages switching-off risks from the mining power networks, in case of insulated resistance faults by using a predictive diagnose method. The cables from the neutral insulated power networks (underground mining) are designed to provide a flexible electrical connection between portable or mobile equipment and a point of supply, including main feeder cable for continuous miners, pump cable, and power supply cable. An electronic protection for insulated resistance of mining power cables can be made using this predictive strategy. The main role of electronic relays for insulation resistance degradation of the electrical power cables, from neutral insulated power networks, is to provide a permanent measurement of the insulated resistance between phases and ground, in order to switch-off voltage when the resistance value is below a standard value. The automat system of protection is able to signalize the failure and the human operator will be early informed about the switch-off power and will have time to take proper measures to fix the failure. This logic for fast and automat switch-off voltage without aprioristic announcement is suitable for the electrical installations, realizing so a protection against fires and explosion. It is presented an algorithm and an anticipative relay for insulated resistance control from three-phase low voltage installations with insulated neutral connection.

Silicon on insulator self-aligned transistors

DOEpatents

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.

KSC-2010-1158

NASA Image and Video Library

2010-01-08

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, construction workers survey the last outside wall of the Propellants North Administrative and Maintenance Facility. Concrete layers on either side of high-density foam insulation in the facility's walls will prevent any transfer of radiant heat between the exterior and interior of the buildings. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2009-6796

NASA Image and Video Library

2009-12-11

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, concrete layers on either side of the high-density foam insulation of the Propellants North Administrative and Maintenance Facility's walls will prevent any transfer of radiant heat between the exterior and interior of the building. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2009-6802

NASA Image and Video Library

2009-12-11

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, high-density foam insulation between the concrete layers of the Propellants North Administrative and Maintenance Facility's walls will prevent any transfer of radiant heat between the exterior and interior of the building. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

A biometeorological procedure for weather forecast to assess the optimal outdoor clothing insulation.

PubMed

Morabito, Marco; Crisci, Alfonso; Cecchi, Lorenzo; Modesti, Pietro Amedeo; Maracchi, Giampiero; Gensini, Gian Franco; Orlandini, Simone

2008-09-01

Clothing insulation represents an important parameter strongly dependent on climate/weather variability and directly involved in the assessment of the human energy balance. Few studies tried to explore the influence of climate changes on the optimal clothing insulation for outdoor spaces. For this reason, the aim of this work was to investigate mainly the optimal outdoor minimum clothing insulation value required to reach the thermal neutrality (min_clo) related to climate change on a seasonal basis. Subsequently, we developed an example of operational biometeorological procedure to provide 72-hour forecast maps concerning the min_clo. Hourly meteorological data were provided by three Italian weather stations located in Turin, Rome and Palermo, for the period 1951-1995. Environmental variables and subjective characteristics referred to an average adult young male at rest and at a very high metabolic rate were used as input variables to calculate the min_clo by using a thermal index based on the human energy balance. Trends of min_clo were assessed by a non-parametric statistical method. Results showed a lower magnitude of trends in a subject at a very high metabolic rate than at rest. Turin always showed a decrease of min_clo during the study period and prevalently negative trends were also observed in Palermo. On the other hand, an opposite situation was observed in Rome, especially during the morning in all seasons. The development of a daily operational procedure to forecast customized min_clo could provide useful information for the outdoor clothing fitting that might help to reduce the weather-related human health risk.

Insulation board and process of making

DOEpatents

Nowobilski, J.J.; Owens, W.J.

1985-08-27

Insulation board is described which is capable of bearing a load without significant loss of insulating capacity due to compression, produced by a method wherein the board is made in compliance with specified conditions of time, temperature and pressure. 2 figs.

Method for forming a thermocouple

DOEpatents

Metz, Hugh J.

1979-01-01

A method is provided for producing a fast response, insulated junction thermocouple having a uniform diameter outer sheath in the region of the measuring junction. One step is added to the usual thermocouple fabrication process that consists in expanding the thermocouple sheath following the insulation removal step. This makes it possible to swage the sheath back to the original diameter and compact the insulation to the desired high density in the final fabrication step.

Analyse dynamique des lignes de grande portee sous charges de vent

NASA Astrophysics Data System (ADS)

Ashby, Mathieu

There are two types of electric crossing : i) subterranean / submarine line ii) overhead-line crossing. We always consider the last one as a more economic option. The inconvenience of an overhead-line crossing would be the environmental constraints among which the existing obstacles, the clearance for the navigation and the aesthetics demanded by the public. The overhead-line crossings usually have conductors of long ranges which are outside of the field of application for the current transmission line codes. These are limited to reaches of a length included between 200 m and 800 m, as well as a height of support lower than 60 m. However, for reaches over 800 m and over a height over 60 m, the criteria of conception in the transmission line codes for the calculation of wind loads are not applicable. In this study we concentrate on loads on the supports owed to the limit wind applied to bare conductors and insulators chains The objective of the present study is to examine the effect of the temporal and spatial correlation of the wind load along the conductors on a finite element model. A special attention was brought to the evaluation of the importance of the dynamic load transmitted on by the conductors and the insulators chains for the case of a turbulent wind load. The numerical study on finite element model for the example of a overhead-line crossing was done with the software ADINA. The wind load for the finite element model for the example of a overhead-line crossing was generated by the software WindGen which uses the method of Simiu-Scanlan and the method of spectral representation developed by Shinozuka-Deodatis. Wind loads generated where integrated into the finite element model ADINA for a dynamic analysis of the overhead-line crossing. For the first part, the current methods are used to calculate the efforts in supports due to the wind loads with an engineering approach and a comparaison approach. The current methods are then compared with the efforts obtained from an advanced method, transient dynamic and spectral stochastic, and specifically for the case of a simple overhead-line and an overhead-line crossings. For the second part, the effect of the longitudinal correlation of the wind load on two parallel conductors was examined. Finally, dynamic experiments on an insulators chain were made to determine the variation of the damping and the rigidity of the system for different type of insulators, different speed of application of the load and the inclination of the insulator. Key words : transient dynamics, spectral stochastic, turbulent wind, conductor, aerodynamic damping, structural damping, spatial correlation, wind spectra

The Application of Surface Potential Test on Hand-making Insulation for Generator Stator End-winding

NASA Astrophysics Data System (ADS)

Lu, Zhu-mao; Liu, Qing; Wang, Tian-zheng; Bai, Lu; Li, Yan-peng

2017-05-01

This paper presents the advantage of surface potential test on hand-making insulation for generator stator end-winding insulation detection, compared with DC or AC withstand voltage test, also details the test principle, connection method and test notes. And through the case, surface potential test on hand-making insulation proved effective for insulation quality detection after generator stator end-winding maintenance, and the experimental data is useful and reliable for the electrical equipment operation and maintenance in the power plant.

Evaluation of Fire Test Methods for Aircraft Thermal Acoustical Insulation

DOT National Transportation Integrated Search

1997-09-01

This report presents the results of laboratory round robin flammability testing performed on thermal acoustical insulation blankets and the films used as insulation coverings. This work was requested by the aircraft industry as a result of actual inc...

Heat Transfer Modeling for Rigid High-Temperature Fibrous Insulation

NASA Technical Reports Server (NTRS)

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

2012-01-01

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

Optimation of cooled shields in insulations

NASA Technical Reports Server (NTRS)

Chato, J. C.; Khodadadi, J. M.; Seyed-Yagoobi, J.

1984-01-01

A method to optimize the location, temperature, and heat dissipation rate of each cooled shield inside an insulation layer was developed. The method is based on the minimization of the entropy production rate which is proportional to the heat leak across the insulation. It is shown that the maximum number of shields to be used in most practical applications is three. However, cooled shields are useful only at low values of the overall, cold wall to hot wall absolute temperature ratio. The performance of the insulation system is relatively insensitive to deviations from the optimum values of the temperature and location of the cooling shields. Design curves for rapid estimates of the locations and temperatures of cooling shields in various types of insulations, and an equation for calculating the cooling loads for the shields are presented.

Waterproof Silicone Coatings of Thermal Insulation and Vaporization Method

NASA Technical Reports Server (NTRS)

Cagliostro, Domenick E. (Inventor)

1999-01-01

Thermal insulation composed of porous ceramic material can be waterproofed by producing a thin silicone film on the surface of the insulation by exposing it to volatile silicone precursors at ambient conditions. When the silicone precursor reactants are multi-functional siloxanes or silanes containing alkenes or alkynes carbon groups higher molecular weight films can be produced. Catalyst are usually required for the silicone precursors to react at room temperature to form the films. The catalyst are particularly useful in the single component system e.g. dimethylethoxysilane (DNMS) to accelerate the reaction and decrease the time to waterproof and protect the insulation. In comparison to other methods, the chemical vapor technique assures better control over the quantity and location of the film being deposited on the ceramic insulation to improve the waterproof coating.

Ceramic electrical insulation for electrical coils, transformers, and magnets

DOEpatents

Rice, John A.; Hazelton, Craig S.; Fabian, Paul E.

2002-01-01

A high temperature electrical insulation is described, which is suitable for electrical windings for any number of applications. The inventive insulation comprises a cured preceramic polymer resin, which is preferably a polysiloxane resin. A method for insulating electrical windings, which are intended for use in high temperature environments, such as superconductors and the like, advantageously comprises the steps of, first, applying a preceramic polymer layer to a conductor core, to function as an insulation layer, and second, curing the preceramic polymer layer. The conductor core preferably comprises a metallic wire, which may be wound into a coil. In the preferred method, the applying step comprises a step of wrapping the conductor core with a sleeve or tape of glass or ceramic fabric which has been impregnated by a preceramic polymer resin. The inventive insulation system allows conducting coils and magnets to be fabricated using existing processing equipment, and maximizes the mechanical and thermal performance at both elevated and cryogenic temperatures. It also permits co-processing of the wire and the insulation to increase production efficiencies and reduce overall costs, while still remarkably enhancing performance.

Thin film module development

NASA Technical Reports Server (NTRS)

Jester, T.

1985-01-01

The design of ARCO Solar, Inc.'s Genesis G100 photovoltaic module was driven by several criteria, including environmental stability (both electrical and mechanical), consumer aesthetics, low materials costs, and manufacturing ease. The module circuitry is designed as a 12 volt battery charger, using monolithic patterning techniques on a glass superstrate. This patterning and interconnect method proves amenable to high volume, low cost production throughput, and the use of glass serves the dual role of handling ease and availability. The mechanical design of the module centers on environmental stability. Packaging of the glass superstrate circuit must provide good resistance to thermal and humidity exposure along with hi-pot insulation and hailstone impact resistance. The options considered are given. Ethylene vinyl acetate (EVA) is chosen as the pottant material for its excellent weatherability.

Method of testing gas insulated systems for the presence of conducting particles utilizing a gas mixture of nitrogen and sulfur hexafluoride

DOEpatents

Wootton, Roy E.

1979-01-01

A method of testing a gas insulated system for the presence of conducting particles. The method includes inserting a gaseous mixture comprising about 98 volume percent nitrogen and about 2 volume percent sulfur hexafluoride into the gas insulated system at a pressure greater than 60 lb./sq. in. gauge, and then applying a test voltage to the system. If particles are present within the system, the gaseous mixture will break down, providing an indicator of the presence of the particles.

Simulated electron affinity tuning in metal-insulator-metal (MIM) diodes

NASA Astrophysics Data System (ADS)

Mistry, Kissan; Yavuz, Mustafa; Musselman, Kevin P.

2017-05-01

Metal-insulator-metal diodes for rectification applications must exhibit high asymmetry, nonlinearity, and responsivity. Traditional methods of improving these figures of merit have consisted of increasing insulator thickness, adding multiple insulator layers, and utilizing a variety of metal contact combinations. However, these methods have come with the price of increasing the diode resistance and ultimately limiting the operating frequency to well below the terahertz regime. In this work, an Airy Function Transfer Matrix simulation method was used to observe the effect of tuning the electron affinity of the insulator as a technique to decrease the diode resistance. It was shown that a small increase in electron affinity can result in a resistance decrease in upwards of five orders of magnitude, corresponding to an increase in operating frequency on the same order. Electron affinity tuning has a minimal effect on the diode figures of merit, where asymmetry improves or remains unaffected and slight decreases in nonlinearity and responsivity are likely to be greatly outweighed by the improved operating frequency of the diode.

Mechanical and electric characteristics of vacuum impregnated no-insulation HTS coil

NASA Astrophysics Data System (ADS)

Park, Heecheol; Kim, A.-rong; Kim, Seokho; Park, Minwon; Kim, Kwangmin; Park, Taejun

2014-09-01

For the conduction cooling application, epoxy impregnation is inevitable to enhance the thermal conduction. However, there have been several research results on the delamination problem with coated conductor and the main cause of the delamination is related with the different thermal contraction between epoxy, the insulation layer and the weak conductor. To avoid this problem, the amount of epoxy and insulation layer between conductors should be minimized or removed. Therefore, no insulation (NI) winding method and impregnation after dry winding can be considered to solve the problem. The NI coil winding method is very attractive due to high mechanical/thermal stability for the special purpose of DC magnets by removing the insulation layer. In this paper, the NI coil winding method and vacuum impregnation are applied to a HTS coil to avoid the delamination problem and enhance the mechanical/thermal stability for the conduction cooling application. Through the charging/discharging operation, electric/thermal characteristics are investigated at 77 K and 30 K.

Show Me the Green

ERIC Educational Resources Information Center

Norbury, Keith

2013-01-01

Gone are the days when green campus initiatives were a balm to the soul and a drain on the wallet. Today's environmental initiatives are all about saving lots of green--in every sense of the word. The environmental benefits of green campus projects--whether wind turbines or better insulation--are pretty clear. Unfortunately, in today's…

Process for making ceramic insulation

DOEpatents

Akash, Akash [Salt Lake City, UT; Balakrishnan, G Nair [Sandy, UT

2009-12-08

A method is provided for producing insulation materials and insulation for high temperature applications using novel castable and powder-based ceramics. The ceramic components produced using the proposed process offers (i) a fine porosity (from nano-to micro scale); (ii) a superior strength-to-weight ratio; and (iii) flexibility in designing multilayered features offering multifunctionality which will increase the service lifetime of insulation and refractory components used in the solid oxide fuel cell, direct carbon fuel cell, furnace, metal melting, glass, chemical, paper/pulp, automobile, industrial heating, coal, and power generation industries. Further, the ceramic components made using this method may have net-shape and/or net-size advantages with minimum post machining requirements.

Doping Effect of Graphene Nanoplatelets on Electrical Insulation Properties of Polyethylene: From Macroscopic to Molecular Scale

PubMed Central

Jing, Ziang; Li, Changming; Zhao, Hong; Zhang, Guiling; Han, Baozhong

2016-01-01

The doping effect of graphene nanoplatelets (GNPs) on electrical insulation properties of polyethylene (PE) was studied by combining experimental and theoretical methods. The electric conduction properties and trap characteristics were tested for pure PE and PE/GNPs composites by using a direct measurement method and a thermal stimulated current (TSC) method. It was found that doping smaller GNPs is more beneficial to decrease the conductivity of PE/GNPs. The PE/GNPs composite with smaller size GNPs mainly introduces deep energy traps, while with increasing GNPs size, besides deep energy traps, shallow energy traps are also introduced. These results were also confirmed by density functional theory (DFT) and the non-equilibrium Green’s function (NEGF) method calculations. Therefore, doping small size GNPs is favorable for trapping charge carriers and enhancing insulation ability, which is suggested as an effective strategy in exploring powerful insulation materials. PMID:28773802

Environmental Assessment: Demolition of McGuire Central Heat Plant at Joint Base McGuire-Dix-Lakehurst, New Jersey

DTIC Science & Technology

2012-06-01

insulation, boiler, holding tank and duct coverings, floor tiles , window caulking/glazing, and corrugated building siding. The asbestos insulation and...facility, with the Bulk Fuel Storage area and the golf course located between them. BOMARC is located several miles from the proposed solar sites...Architectural Resources The Central Heat Plant was constructed in 1956. It is a flat- roofed building originally rectangular in form, and is now L-shaped. The

A Guide to Electrical Insulation Design in Aerospace Vehicles for a Broad Range of Environmental Parameter Space

DTIC Science & Technology

2010-03-01

as an example with information from Llewellyn Jones (1939) [30] and from Meek (1978), pg. 233 [7]. Morokuma (1969) [31] varied the surface potential...breakdown in high pressure gases,” Phys. Rev. A, 21, 2069. 13. Dutton, J., Llewellyn Jones , F., and Palmer, R.W., (1961), Proc. Phys. Soc. 78, 569...breakdown and insulators in compressed gas,” IEE Proc. 128, 303. 30. Llewellyn Jones , F. (1939), Phil. Mag. 28, 192. 31. Morokuma, Y., Nakamura, Y., and

Ballistic Performance of Porous Ceramic Thermal Protection Systems at 9 km/s

NASA Technical Reports Server (NTRS)

Miller, Joshua E.; Bohl, W. E.; Foreman, C. D.; Christiansen, Eric L.; Davis, B. A.

2009-01-01

Porous-ceramic, thermal-protection-systems are used heavily in current reentry vehicles like the Orbiter, and they are currently being proposed for the next generation of manned spacecraft, Orion. These materials insulate the structural components and sensitive electronic components of a spacecraft against the intense thermal environments of atmospheric reentry. Furthermore, these materials are also highly exposed to space environmental hazards like meteoroid and orbital debris impacts. This paper discusses recent impact testing up to 9 km/s on ceramic tiles similar to those used on the Orbiter. These tiles have a porous-batting of nominally 8 lb/cubic ft alumina-fiber-enhanced-thermal-barrier (AETB8) insulating material coated with a damage-resistant, toughened-unipiece-fibrous-insulation (TUFI) layer.

[Asbestos exposure on board ships: a study of the environmental situation on 2 classes of ferryboats].

PubMed

Turi, E; Tidei, F; Paoletti, L

1993-01-01

The article describes the results of a study on contamination by airborne asbestos fibres on board a number of ships belonging to fleets operating from Civitavecchia, a port on the coast of central Italy. Asbestos was widely used throughout the ships as fire- and soundproofing insulation. Samples taken before, during and after removal of the insulation in areas of the ship outside the asbestos removal worksite gave concentration levels that were similar to those observed in other indoor environments (building), varying according to the sample location and the condition of the insulation material. The results are discussed taking into consideration the fact that a ship is also a living environment for crew and passengers.

A Study of the Electrostatic Interaction Between Insulators and Martian/Lunar Soil Simulants

NASA Technical Reports Server (NTRS)

Mantovani, James G.

2001-01-01

Using our previous experience with the Mars Environmental Compatibility Assessment (MECA) electrometer, we have designed a new type of aerodynamic electrometer. The goal of the research was to measure the buildup of electrostatic surface charge on a stationary cylindrical insulator after windborne granular particles have collided with the insulator surface in a simulated dust storm. The experiments are performed inside a vacuum chamber. This allows the atmospheric composition and pressure to be controlled in order to simulate the atmospheric conditions near the equator on the Martian surface. An impeller fan was used to propel the dust particles at a cylindrically shaped insulator under low vacuum conditions. We tested the new electrometer in a 10 mbar CO2 atmosphere by exposing two types of cylindrical insulators, Teflon (1.9 cm diameter) and Fiberglass (2.5 cm diameter), to a variety of windborne granular particulate materials. The granular materials tested were JSC Mars-1 simulant, which is a mixture of coarse and fine (<5microns diameter) particle sizes, and some of the major mineral constituents of the Martian soil. The minerals included Ottawa sand (SiO2), iron oxide (Fe2O3), aluminum oxide (Al2O3) and magnesium oxide (MgO). We also constructed a MECA-like electrometer that contained an insulator capped planar electrode for measuring the amount of electrostatic charge produced by rubbing an insulator surface over Martian and lunar soil simulants. The results of this study indicate that it is possible to detect triboelectric charging of insulator surfaces by windborne Martian soil simulant, and by individual mineral constituents of the soil simulant. We have also found that Teflon and Fiberglass insulator surfaces respond in different ways by developing opposite polarity surface charge, which decays at different rates after the particle impacts cease.

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

NASA Technical Reports Server (NTRS)

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.

System and method for evaluating a wire conductor

DOEpatents

Panozzo, Edward; Parish, Harold

2013-10-22

A method of evaluating an electrically conductive wire segment having an insulated intermediate portion and non-insulated ends includes passing the insulated portion of the wire segment through an electrically conductive brush. According to the method, an electrical potential is established on the brush by a power source. The method also includes determining a value of electrical current that is conducted through the wire segment by the brush when the potential is established on the brush. The method additionally includes comparing the value of electrical current conducted through the wire segment with a predetermined current value to thereby evaluate the wire segment. A system for evaluating an electrically conductive wire segment is also disclosed.

Influence of Insulation Monitoring Devices on the Operation of DC Control Circuits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszowiec, Piotr, E-mail: olpio@o2.pl

The insulation level of DC control circuits is an important safety-critical factor and, thus, should be subject to continuous and periodic monitoring. The methods used for monitoring the insulation in live circuits may, however, disturb the reliable operation of control relays. The risks of misoperation and failure to reset of relays posed by the operation of various insulation monitoring and fault location systems are evaluated.

Next Generation Wiring

NASA Technical Reports Server (NTRS)

Medelius, Petro; Jolley, Scott; Fitzpatrick, Lilliana; Vinje, Rubiela; Williams, Martha; Clayton, LaNetra; Roberson, Luke; Smith, Trent; Santiago-Maldonado, Edgardo

2007-01-01

Wiring is a major operational component on aerospace hardware that accounts for substantial weight and volumetric space. Over time wire insulation can age and fail, often leading to catastrophic events such as system failure or fire. The next generation of wiring must be reliable and sustainable over long periods of time. These features will be achieved by the development of a wire insulation capable of autonomous self-healing that mitigates failure before it reaches a catastrophic level. In order to develop a self-healing insulation material, three steps must occur. First, methods of bonding similar materials must be developed that are capable of being initiated autonomously. This process will lead to the development of a manual repair system for polyimide wire insulation. Second, ways to initiate these bonding methods that lead to materials that are similar to the primary insulation must be developed. Finally, steps one and two must be integrated to produce a material that has no residues from the process that degrades the insulating properties of the final repaired insulation. The self-healing technology, teamed with the ability to identify and locate damage, will greatly improve reliability and safety of electrical wiring of critical systems. This paper will address these topics, discuss the results of preliminary testing, and remaining development issues related to self-healing wire insulation.

Insulation Materials Comprising Fibers Having a Partially Cured Polymer Coating Thereon, Articles Including Such Insulation Materials, and Methods of Forming Such Materials and Articles

NASA Technical Reports Server (NTRS)

Morgan, Richard E. (Inventor); Meeks, Craig L. (Inventor)

2017-01-01

Insulation materials have a coating of a partially cured polymer on a plurality of fibers, and the plurality of coated fibers in a cross-linked polymeric matrix. Insulation may be formed by applying a preceramic polymer to a plurality of fibers, heating the preceramic polymer to form a partially cured polymer over at least portions of the plurality of fibers, disposing the plurality of fibers in a polymeric material, and curing the polymeric material. A rocket motor may be formed by disposing a plurality of coated fibers in an insulation precursor, curing the insulation precursor to form an insulation material without sintering the partially cured polymer, and providing an energetic material over the polymeric material. An article includes an insulation material over at least one surface.

Development of method to characterize emissions from spray polyurethane foam insulation

EPA Science Inventory

This presentation updates symposium participants re EPA progress towards development of SPF insulation emissions characterization methods. The presentation highlights evaluation of experiments investigating emissions after application of SPF to substrates in micro chambers and i...

Composite Flexible Blanket Insulation

NASA Technical Reports Server (NTRS)

Kourtides, Demetrius A. (Inventor); Pitts, William C. (Inventor); Goldstein, Howard E. (Inventor); Sawko, Paul M. (Inventor)

1991-01-01

Composite flexible multilayer insulation systems (MLI) were evaluated for thermal performance and compared with the currently used fibrous silica (baseline) insulation system. The systems described are multilayer insulations consisting of alternating layers of metal foil and scrim ceramic cloth or vacuum metallized polymeric films quilted together using ceramic thread. A silicon carbide thread for use in the quilting and the method of making it are also described. These systems are useful in providing lightweight insulation for a variety of uses, particularly on the surface of aerospace vehicles subject to very high temperatures during flight.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Measurements of Electrical and Electron Emission Properties of Highly Insulating Materials

NASA Technical Reports Server (NTRS)

Dennison, J. R.; Brunson, Jerilyn; Hoffman, Ryan; Abbott, Jonathon; Thomson, Clint; Sim, Alec

2005-01-01

Highly insulating materials often acquire significant charges when subjected to fluxes of electrons, ions, or photons. This charge can significantly modify the materials properties of the materials and have profound effects on the functionality of the materials in a variety of applications. These include charging of spacecraft materials due to interactions with the severe space environment, enhanced contamination due to charging in Lunar of Martian environments, high power arching of cables and sources, modification of tethers and ion thrusters for propulsion, and scanning electron microscopy, to name but a few examples. This paper describes new techniques and measurements of the electron emission properties and resistivity of highly insulating materials. Electron yields are a measure of the number of electrons emitted from a material per incident particle (electron, ion or photon). Electron yields depend on incident species, energy and angle, and on the material. They determine the net charge acquired by a material subject to a give incident flu. New pulsed-beam techniques will be described that allow accurate measurement of the yields for uncharged insulators and measurements of how the yields are modified as charge builds up in the insulator. A key parameter in modeling charge dissipation is the resistivity of insulating materials. This determines how charge will accumulate and redistribute across an insulator, as well as the time scale for charge transport and dissipation. Comparison of new long term constant-voltage methods and charge storage methods for measuring resistivity of highly insulating materials will be compared to more commonly used, but less accurate methods.

7 CFR 1755.860 - RUS specification for filled buried wires.

Code of Federal Regulations, 2012 CFR

2012-01-01

... sufficient heat barrier to prevent visible evidence of conductor insulation deformation or adhesion between... Insulations and Jackets for Telecommunications Wire and Cable; ASTM D 4566-90, Standard Test Methods for Electrical Performance Properties of Insulations and Jackets for Telecommunications Wire and Cable; ASTM D...

7 CFR 1755.860 - RUS specification for filled buried wires.

Code of Federal Regulations, 2014 CFR

2014-01-01

... sufficient heat barrier to prevent visible evidence of conductor insulation deformation or adhesion between... Insulations and Jackets for Telecommunications Wire and Cable; ASTM D 4566-90, Standard Test Methods for Electrical Performance Properties of Insulations and Jackets for Telecommunications Wire and Cable; ASTM D...

7 CFR 1755.860 - RUS specification for filled buried wires.

Code of Federal Regulations, 2013 CFR

2013-01-01

... sufficient heat barrier to prevent visible evidence of conductor insulation deformation or adhesion between... Insulations and Jackets for Telecommunications Wire and Cable; ASTM D 4566-90, Standard Test Methods for Electrical Performance Properties of Insulations and Jackets for Telecommunications Wire and Cable; ASTM D...

A test and instrumentation system for the investigation of degradation of electrical insulating materials

NASA Technical Reports Server (NTRS)

1982-01-01

The basic test methods of aging and deterioration mechanisms of electrical insulating materials are discussed. A comprehensive test system developed to study the degradation process is described. This system is completely checked, and calibrated with a few insulating material samples.

Transport jet aircraft noise abatement in foreign countries: Growth, structure, impact. Volume 2: Pacific basin, August 1980

NASA Technical Reports Server (NTRS)

Spencer, F. A.

1980-01-01

Noise control measures at the international airports of Hawaii, New Zealand, Australia, Hong Kong, Japan, and Singapore were studied. Factors in noise control, such as government structure are examined. The increasing power of environmental agencies vis-a-vis aviation departments is noted. The following methods of dealing with aircraft noise are examined by type of control: noise at the source control; noise emmission controls, zoning, building codes, subsidies for relocation, insulation, loss in property values, and for TV, radio and telephone interference; and noise-related landing charges.

Analytical study of temperature distribution in a rectangular porous fin considering both insulated and convective tip

NASA Astrophysics Data System (ADS)

Deshamukhya, Tuhin; Bhanja, Dipankar; Nath, Sujit; Maji, Ambarish; Choubey, Gautam

2017-07-01

The following study is concerned with determination of temperature distribution of porous fins under convective and insulated tip conditions. The authors have made an effort to study the effect of various important parameters involved in the transfer of heat through porous fins as well as the temperature distribution along the fin length subjected to both convective as well as insulated ends. The non-linear equation obtained has been solved by Adomian Decomposition method and validated with a numerical scheme called Finite Difference method by using a central difference scheme and Gauss Siedel Iterative method.

Study on the method of improving the flashover voltage of 110kV suspension porcelain insulators based on neural network genetic algorithm

NASA Astrophysics Data System (ADS)

Zhang, Ruiqi; Cai, Li; Chen, Junwu; Wang, Luo; Tan, Xuefeng

2018-04-01

This paper presents a new method to improve 110kV porcelain insulator flashover voltage by adding a metal ring on the insulator cap, which can not only effectively reduce the field strength of the steel cap, but also reduce the tangential field intensity of the umbrella group and inhibit the development of the discharge process, thus the flashover voltage can be increased. The surface strength calculation model of 110kV porcelain insulator is established by the finite element method (FEM), and the parameters of the metal ring are designed by neural network genetic algorithm (BP-GA). Then the experiments were carried out to verify the results, and the results show that the metal ring plate under the optimum parameters can greatly improve the flashover voltage.

Insulator (Heat and Frost). Occupational Analyses Series.

ERIC Educational Resources Information Center

McRory, Aline; Ally, Mohamed

This analysis covers tasks performed by an insulator, an occupational title some provinces and territories of Canada have also identified as heat and frost insulator. A guide to analysis discusses development, structure, and validation method; scope of the occupation; trends; and safety. To facilitate understanding the nature of the occupation,…

Method and apparatus for connecting high voltage leads to a high temperature super-conducting transformer

DOEpatents

Golner, Thomas M.; Mehta, Shirish P.

2005-07-26

A method and apparatus for connecting high voltage leads to a super-conducting transformer is provided that includes a first super-conducting coil set, a second super-conducting coil set, and a third super-conducting coil set. The first, second and third super-conducting coil sets are connected via an insulated interconnect system that includes insulated conductors and insulated connectors that are utilized to connect the first, second, and third super-conducting coil sets to the high voltage leads.

Method of fabricating high-density hermetic electrical feedthroughs using insulated wire bundles

DOEpatents

Shah, Kedar G.; Benett, William J.; Pannu, Satinderpall S.

2016-05-10

A method of fabricating electrical feedthroughs coats of a plurality of electrically conductive wires with an electrically insulating material and bundles the coated wires together in a substantially parallel arrangement. The bundled coated wires are secured to each other by joining the electrically insulating material of adjacent wires together to form a monolithic block which is then cut transverse to the wires to produce a block section having opposing first and second sides with a plurality of electrically conductive feedthroughs extending between them.

KSC-2010-1159

NASA Image and Video Library

2010-01-08

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, with the placement of the last outside wall of the Propellants North Administrative and Maintenance Facility, the "barn-raising" of the new "green" facility is complete. Concrete layers on either side of high-density foam insulation in the facility's walls will prevent any transfer of radiant heat between the exterior and interior of the buildings. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1114

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - The 525-foot-tall Vehicle Assembly Building, in the background, is witness to the formation of the Propellants North Administrative and Maintenance Facility, a new "green" building under construction in Launch Complex 39 at NASA's Kennedy Space Center in Florida. Concrete layers on either side of high-density foam insulation in the facility's walls will prevent any transfer of radiant heat between the exterior and interior of the buildings. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1160

NASA Image and Video Library

2010-01-08

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, this crane raised all of the outside walls of the Propellants North Administrative and Maintenance Facility over a period of two days. Concrete layers on either side of high-density foam insulation in the facility's walls will prevent any transfer of radiant heat between the exterior and interior of the buildings. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1157

NASA Image and Video Library

2010-01-08

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, all of the exterior walls of the Propellants North Administrative and Maintenance Facility have been lifted into place. Concrete layers on either side of high-density foam insulation in the facility's walls will prevent any transfer of radiant heat between the exterior and interior of the buildings. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1161

NASA Image and Video Library

2010-01-08

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, construction of the Propellants North Administrative and Maintenance Facility is moving ahead with the placement of all of the outside walls complete. Concrete layers on either side of high-density foam insulation in the facility's walls will prevent any transfer of radiant heat between the exterior and interior of the buildings. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1156

NASA Image and Video Library

2010-01-08

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, the last outside wall of the Propellants North Administrative and Maintenance Facility is lifted into place. Concrete layers on either side of high-density foam insulation in the facility's walls will prevent any transfer of radiant heat between the exterior and interior of the buildings. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

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

NASA Astrophysics Data System (ADS)

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.

Polybenzoxazole-filled nitrile butadiene rubber compositions

NASA Technical Reports Server (NTRS)

Gajiwala, Himansu M. (Inventor); Guillot, David G. (Inventor)

2008-01-01

An insulation composition that comprises at least one nitrile butadiene rubber (NBR) having an acrylonitrile content that ranges from approximately 26% by weight to approximately 35% by weight and polybenzoxazole (PBO) fibers. The NBR may be a copolymer of acrylonitrile and butadiene and may be present in the insulation composition in a range of from approximately 45% by weight to approximately 56% by weight of a total weight of the insulation composition. The PBO fibers may be present in a range of from approximately 3% by weight to approximately 10% by weight of a total weight of the insulation composition. A rocket motor including the insulation composition and a method of insulating a rocket motor are also disclosed.

High power density capacitor and method of fabrication

DOEpatents

Tuncer, Enis

2012-11-20

A ductile preform for making a drawn capacitor includes a plurality of electrically insulating, ductile insulator plates and a plurality of electrically conductive, ductile capacitor plates. Each insulator plate is stacked vertically on a respective capacitor plate and each capacitor plate is stacked on a corresponding insulator plate in alignment with only one edge so that other edges are not in alignment and so that each insulator plate extends beyond the other edges. One or more electrically insulating, ductile spacers are disposed in horizontal alignment with each capacitor plate along the other edges and the pattern is repeated so that alternating capacitor plates are stacked on alternating opposite edges of the insulator plates. A final insulator plate is positioned at an extremity of the preform. The preform may then be drawn to fuse the components and decrease the dimensions of the preform that are perpendicular to the direction of the draw.

Cryogenic Insulation Systems

NASA Technical Reports Server (NTRS)

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

1999-01-01

The results of a comparative study of cryogenic insulation systems performed are presented. The key aspects of thermal insulation relative to cryogenic system design, testing, manufacturing, and maintenance are discussed. An overview of insulation development from an energy conservation perspective is given. Conventional insulation materials for cryogenic applications provide three levels of thermal conductivity. Actual thermal performance of standard multilayer insulation (MLI) is several times less than laboratory performance and often 10 times worse than ideal performance. The cost-effectiveness of the insulation system depends on thermal performance; flexibility and durability; ease of use in handling, installation, and maintenance; and overall cost including operations, maintenance, and life cycle. Results of comprehensive testing of both conventional and novel materials such as aerogel composites using cryostat boil-off methods are given. The development of efficient, robust cryogenic insulation systems that operate at a soft vacuum level is the primary focus of this paper.

Electron spin resonance spectral study of PVC and XLPE insulation materials and their life time analysis.

PubMed

Morsy, M A; Shwehdi, M H

2006-03-01

Electron spin resonance (ESR) study is carried out to characterize thermal endurance of insulating materials used in power cable industry. The presented work provides ESR investigation and evaluation of widely used cable insulation materials, namely polyvinyl chloride (PVC) and cross-linked polyethylene (XLPE). The results confirm the fact that PVC is rapidly degrades than XLPE. The study also indicates that colorants and cable's manufacturing processes enhance the thermal resistance of the PVC. It also verifies the powerfulness and the importance of the ESR-testing of insulation materials compared to other tests assumed by International Electrotechnical Commission (IEC) Standard 216-procedure, e.g. weight loss (WL), electric strength (ES) or tensile strength (TS). The estimated thermal endurance parameters by ESR-method show that the other standard methods overestimate these parameters and produce less accurate thermal life time curves of cable insulation materials.

Modeling and Sound Insulation Performance Analysis of Two Honeycomb-hole Coatings

NASA Astrophysics Data System (ADS)

Ye, H. F.; Tao, M.; Zhang, W. Z.

2018-05-01

During the sound transmission loss test in the standing-wave tube, the unavoidable reflected wave from the termination of downstream tube would affect the precision measurement of sound transmission loss(TL). However, it can be solved by defining the non-reflected boundary conditions when modeling based on the finite element method. Then, the model has been validated by comparing with the analytical method. Based on the present model, the sound insulation performance of two types of honeycomb-hole coatings have been analyzed and discussed. Moreover, the changes of parameters play an important role on the sound insulation performance of honeycomb-hole coating and the negative Poisson’s ratio honeycomb-hole coating has better sound insulation performance at special frequencies. Finally, it is summarized that sound insulation performance is the result of various factors that include the impedance changes, the waveform transformation and so on.

Mining CRRES IDM Pulse Data and CRRES Environmental Data to Improve Spacecraft Charging/Discharging Models and Guidelines

NASA Technical Reports Server (NTRS)

Brautigam, D. H.; Frederickson, A. R.

2004-01-01

One can truly predict the charging and pulsing in space over a year's time using only the physics that worked for periods of an hour and less in prior publications. All portions of the task were achieved, including the optional portion of determining a value for conductivity that best .t the data. Fortran statements were developed that are required for the NUMIT runs to work with this kind of data from space. In addition to developing the Fortran for NUMIT, simple correlations between the IDM pulsing history and the space radiation were observed because we now have a better characterization of the space radiation. The study showed that: (1) the new methods for measurement of charge storage and conduction in insulators provide the correct values to use for prediction of charging and pulsing in space; (2) the methods in NUMIT that worked well for time durations less than hours now work well for durations of months; (3) an average spectrum such as AE8 is probably not a good guide for predicting pulsing in space one must take time dependence into account in order to understand insulator pulsing; and (4) the old method for predicting pulse rates in space that was based on the CRRES data could be improved to include dependencies on material parameters.

Design analysis of ceramic and polymer 150 kV insulators for tropical condition using quickfield software

NASA Astrophysics Data System (ADS)

Walukow, Stephy B.; Manjang, Salama; Zainuddin, Zahir; Samman, Faizal Arya

2018-03-01

This research is to analyze design of ceramic and polymer 150 kV insulators for the tropical area. The use of an insulator certainly requires an electric field. The leakage current and breakdown voltage this happens the contaminant on the surface of the insulator. This type of contaminant can be rain, dust, salt air, extreme weather (much in tropical climates), industrial pollutants and cracks on the surface resulting in collisions. The method used in this research is magnetic field and electric field isolator using Quicfield software. To get the test results variation ranges 20 kV, 70 kV and 150 kV. Side effects of magnetic and electric fields around the insulator. The simulation results show the accumulated contaminants on the surface. Planning should be done in insulator insulator on unstable insulator. Thus, the approach using this commercially available software can be applied to. Therefore, the development of further simulations on the different types of composite insulators used on.

Detection of UV Pulse from Insulators and Application in Estimating the Conditions of Insulators

NASA Astrophysics Data System (ADS)

Wang, Jingang; Chong, Junlong; Yang, Jie

2014-10-01

Solar radiation in the band of 240-280 nm is absorbed by the ozone layer in the atmosphere, and corona discharges from high-voltage apparatus emit in air mainly in the 230-405 nm range of ultraviolet (UV), so the band of 240-280 nm is called UV Solar Blind Band. When the insulators in a string deteriorate or are contaminated, the voltage distribution along the string will change, which causes the electric fields in the vicinity of insulators change and corona discharge intensifies. An UV pulse detection method to check the conditions of insulators is presented based on detecting the UV pulse among the corona discharge, then it can be confirmed that whether there exist faulty insulators and whether the surface contamination of insulators is severe for the safe operation of power systems. An UV-I Insulator Detector has been developed, and both laboratory tests and field tests have been carried out which demonstrates the practical viability of UV-I Insulator Detector for online monitoring.

Initial and Long-Term Movement of Cladding Installed Over Exterior Rigid Insulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, Peter

Changes in the International Energy Conservation Code (IECC) from 2009 to 2012 have resulted in the use of exterior rigid insulation becoming part of the prescriptive code requirements. With more jurisdictions adopting the 2012 IECC builders will be required to incorporate exterior insulation in the construction of their exterior wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location. This research was an extension onmore » previous research conducted by Building Science Corporation in 2011, and 2012. Each year the understanding of the system discrete load component interactions, as well as impacts of environmental loading, has increased. The focus of the research was to examine more closely the impacts of screw fastener bending on the total system capacity, effects of thermal expansion and contraction of materials on the compressive forces in the assembly, as well as to analyze a full year’s worth of cladding movement data from assemblies constructed in an exposed outdoor environment.« less

Human tRNA genes function as chromatin insulators

PubMed Central

Raab, Jesse R; Chiu, Jonathan; Zhu, Jingchun; Katzman, Sol; Kurukuti, Sreenivasulu; Wade, Paul A; Haussler, David; Kamakaka, Rohinton T

2012-01-01

Insulators help separate active chromatin domains from silenced ones. In yeast, gene promoters act as insulators to block the spread of Sir and HP1 mediated silencing while in metazoans most insulators are multipartite autonomous entities. tDNAs are repetitive sequences dispersed throughout the human genome and we now show that some of these tDNAs can function as insulators in human cells. Using computational methods, we identified putative human tDNA insulators. Using silencer blocking, transgene protection and repressor blocking assays we show that some of these tDNA-containing fragments can function as barrier insulators in human cells. We find that these elements also have the ability to block enhancers from activating RNA pol II transcribed promoters. Characterization of a putative tDNA insulator in human cells reveals that the site possesses chromatin signatures similar to those observed at other better-characterized eukaryotic insulators. Enhanced 4C analysis demonstrates that the tDNA insulator makes long-range chromatin contacts with other tDNAs and ETC sites but not with intervening or flanking RNA pol II transcribed genes. PMID:22085927

Direct detection of metal-insulator phase transitions using the modified Backus-Gilbert method

NASA Astrophysics Data System (ADS)

Ulybyshev, Maksim; Winterowd, Christopher; Zafeiropoulos, Savvas

2018-03-01

The detection of the (semi)metal-insulator phase transition can be extremely difficult if the local order parameter which characterizes the ordered phase is unknown. In some cases, it is even impossible to define a local order parameter: the most prominent example of such system is the spin liquid state. This state was proposed to exist in the Hubbard model on the hexagonal lattice in a region between the semimetal phase and the antiferromagnetic insulator phase. The existence of this phase has been the subject of a long debate. In order to detect these exotic phases we must use alternative methods to those used for more familiar examples of spontaneous symmetry breaking. We have modified the Backus-Gilbert method of analytic continuation which was previously used in the calculation of the pion quasiparticle mass in lattice QCD. The modification of the method consists of the introduction of the Tikhonov regularization scheme which was used to treat the ill-conditioned kernel. This modified Backus-Gilbert method is applied to the Euclidean propagators in momentum space calculated using the hybrid Monte Carlo algorithm. In this way, it is possible to reconstruct the full dispersion relation and to estimate the mass gap, which is a direct signal of the transition to the insulating state. We demonstrate the utility of this method in our calculations for the Hubbard model on the hexagonal lattice. We also apply the method to the metal-insulator phase transition in the Hubbard-Coulomb model on the square lattice.

Analysis of the Influence of Construction Insulation Systems on Public Safety in China

PubMed Central

Zhang, Guowei; Zhu, Guoqing; Zhao, Guoxiang

2016-01-01

With the Government of China’s proposed Energy Efficiency Regulations (GB40411-2007), the implementation of external insulation systems will be mandatory in China. The frequent external insulation system fires cause huge numbers of casualties and extensive property damage and have rapidly become a new hot issue in construction evacuation safety in China. This study attempts to reconstruct an actual fire scene and propose a quantitative risk assessment method for upward insulation system fires using thermal analysis tests and large eddy simulations (using the Fire Dynamics Simulator (FDS) software). Firstly, the pyrolysis and combustion characteristics of Extruded polystyrene board (XPS panel), such as ignition temperature, combustion heat, limiting oxygen index, thermogravimetric analysis and thermal radiation analysis were studied experimentally. Based on these experimental data, large eddy simulation was then applied to reconstruct insulation system fires. The results show that upward insulation system fires could be accurately reconstructed by using thermal analysis test and large eddy simulation. The spread of insulation material system fires in the vertical direction is faster than that in the horizontal direction. Moreover, we also find that there is a possibility of flashover in enclosures caused by insulation system fires as the smoke temperature exceeds 600 °C. The simulation methods and experimental results obtained in this paper could provide valuable references for fire evacuation, hazard assessment and fire resistant construction design studies. PMID:27589774

Analysis of the Influence of Construction Insulation Systems on Public Safety in China.

PubMed

Zhang, Guowei; Zhu, Guoqing; Zhao, Guoxiang

2016-08-30

With the Government of China's proposed Energy Efficiency Regulations (GB40411-2007), the implementation of external insulation systems will be mandatory in China. The frequent external insulation system fires cause huge numbers of casualties and extensive property damage and have rapidly become a new hot issue in construction evacuation safety in China. This study attempts to reconstruct an actual fire scene and propose a quantitative risk assessment method for upward insulation system fires using thermal analysis tests and large eddy simulations (using the Fire Dynamics Simulator (FDS) software). Firstly, the pyrolysis and combustion characteristics of Extruded polystyrene board (XPS panel), such as ignition temperature, combustion heat, limiting oxygen index, thermogravimetric analysis and thermal radiation analysis were studied experimentally. Based on these experimental data, large eddy simulation was then applied to reconstruct insulation system fires. The results show that upward insulation system fires could be accurately reconstructed by using thermal analysis test and large eddy simulation. The spread of insulation material system fires in the vertical direction is faster than that in the horizontal direction. Moreover, we also find that there is a possibility of flashover in enclosures caused by insulation system fires as the smoke temperature exceeds 600 °C. The simulation methods and experimental results obtained in this paper could provide valuable references for fire evacuation, hazard assessment and fire resistant construction design studies.

Unsteady Heat Transfer Behavior of Reinforced Concrete Wall of Cold Storage

NASA Astrophysics Data System (ADS)

Nomura, Tomohiro; Murakami, Yuji; Uchikawa, Motoyuki

The authors had already clarified that the heat transfer behaviors between internal and external insulated reinforced concrete wall of cold storage are different each others when inside and outside temperature of wall is flactuating. From that conclusion, we must consider the application method of wall insulation of cold storages in actual design. The theme of the paper is to get the analyzing method and unsteady heat transfer characteristics of concrete walls of cold storage during daily variation of outside temperature of walls, and to give the basis for efficient design and cost optimization of insulate wall of cold storage. The difference of unsteady heat transfer characteristics between internal and external insulate wall, when outside temperature of the wall follewed daily varation, was clarified in experiment and in situ measurement of practical cold storage. The analyzing method with two dimentional unsteady FEM was introduced. Using this method, it is possible to obtain the time variation of heat flux, which is important basic factor for practical design of cold storage, through the wall.

Silicon Carbide Transistor For Detecting Hydrocarbon Gases

NASA Technical Reports Server (NTRS)

Shields, Virgil B.; Ryan, Margaret A.; Williams, Roger M.

1996-01-01

Proposed silicon carbide variable-potential insulated-gate field-effect transistor specially designed for use in measuring concentrations of hydrocarbon gases. Devices like this prove useful numerous automotive, industrial, aeronautical, and environmental monitoring applications.

Determination of the density of surface states at the semiconductor-insulator interface in a metal-insulator-semiconductor structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gulyamov, G., E-mail: Gulyamov1949@rambler.ru; Sharibaev, N. U.

2011-02-15

The temporal dependence of thermal generation of electrons from occupied surface states at the semiconductor-insulator interface in a metal-insulator-semiconductor structure is studied. It is established that, at low temperatures, the derivative of the probability of depopulation of occupied surface states with respect to energy is represented by the Dirac {delta} function. It is shown that the density of states of a finite number of discrete energy levels under high-temperature measurements manifests itself as a continuous spectrum, whereas this spectrum appears discrete at low temperatures. A method for processing the continuous spectrum of the density of surface states is suggested thatmore » method makes it possible to determine the discrete energy spectrum. The obtained results may be conducive to an increase in resolution of the method of non-stationary spectroscopy of surface states.« less

Multilayer insulation blanket, fabricating apparatus and method

DOEpatents

Gonczy, John D.; Niemann, Ralph C.; Boroski, William N.

1992-01-01

An improved multilayer insulation blanket for insulating cryogenic structures operating at very low temperatures is disclosed. An apparatus and method for fabricating the improved blanket are also disclosed. In the improved blanket, each successive layer of insulating material is greater in length and width than the preceding layer so as to accommodate thermal contraction of the layers closest to the cryogenic structure. The fabricating apparatus has a rotatable cylindrical mandrel having an outer surface of fixed radius that is substantially arcuate, preferably convex, in cross-section. The method of fabricating the improved blanket comprises (a) winding a continuous sheet of thermally reflective material around the circumference of the mandrel to form multiple layers, (b) binding the layers along two lines substantially parallel to the edges of the circumference of the mandrel, (c) cutting the layers along a line parallel to the axle of the mandrel, and (d) removing the bound layers from the mandrel.

Method of fabricating a multilayer insulation blanket

DOEpatents

Gonczy, John D.; Niemann, Ralph C.; Boroski, William N.

1993-01-01

An improved multilayer insulation blanket for insulating cryogenic structures operating at very low temperatures is disclosed. An apparatus and method for fabricating the improved blanket are also disclosed. In the improved blanket, each successive layer of insulating material is greater in length and width than the preceding layer so as to accommodate thermal contraction of the layers closest to the cryogenic structure. The fabricating apparatus has a rotatable cylindrical mandrel having an outer surface of fixed radius that is substantially arcuate, preferably convex, in cross-section. The method of fabricating the improved blanket comprises (a) winding a continuous sheet of thermally reflective material around the circumference of the mandrel to form multiple layers, (b) binding the layers along two lines substantially parallel to the edges of the circumference of the mandrel, (c) cutting the layers along a line parallel to the axle of the mandrel, and (d) removing the bound layers from the mandrel.

Method of fabricating a multilayer insulation blanket

DOEpatents

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

1993-07-06

An improved multilayer insulation blanket for insulating cryogenic structures operating at very low temperatures is disclosed. An apparatus and method for fabricating the improved blanket are also disclosed. In the improved blanket, each successive layer of insulating material is greater in length and width than the preceding layer so as to accommodate thermal contraction of the layers closest to the cryogenic structure. The fabricating apparatus has a rotatable cylindrical mandrel having an outer surface of fixed radius that is substantially arcuate, preferably convex, in cross-section. The method of fabricating the improved blanket comprises (a) winding a continuous sheet of thermally reflective material around the circumference of the mandrel to form multiple layers, (b) binding the layers along two lines substantially parallel to the edges of the circumference of the mandrel, (c) cutting the layers along a line parallel to the axle of the mandrel, and (d) removing the bound layers from the mandrel.

Multilayer insulation blanket, fabricating apparatus and method

DOEpatents

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

1992-09-01

An improved multilayer insulation blanket for insulating cryogenic structures operating at very low temperatures is disclosed. An apparatus and method for fabricating the improved blanket are also disclosed. In the improved blanket, each successive layer of insulating material is greater in length and width than the preceding layer so as to accommodate thermal contraction of the layers closest to the cryogenic structure. The fabricating apparatus has a rotatable cylindrical mandrel having an outer surface of fixed radius that is substantially arcuate, preferably convex, in cross-section. The method of fabricating the improved blanket comprises (a) winding a continuous sheet of thermally reflective material around the circumference of the mandrel to form multiple layers, (b) binding the layers along two lines substantially parallel to the edges of the circumference of the mandrel, (c) cutting the layers along a line parallel to the axle of the mandrel, and (d) removing the bound layers from the mandrel. 7 figs.

Radiation-hard electrical coil and method for its fabrication

DOEpatents

Grieggs, R.J.; Blake, R.D.; Gac, F.D.

1982-06-29

A radiation-hard insulated electrical coil and method for making the same are disclosed. In accordance with the method, a conductor, preferably copper, is wrapped with an aluminum strip and then tightly wound into a coil. The aluminum-wrapped coil is then annealed to relax the conductor in the coiled configuration. The annealed coil is then immersed in an alkaline solution to dissolve the aluminum strip, leaving the bare conductor in a coiled configuration with all of the windings closely packed yet uniformly spaced from one another. The coil is then insulated with a refractory insulating material. In the preferred embodiment, the coil is insulated by coating it with a vitreous enamel and subsequently potting the enamelled coil in a castable ceramic concrete. The resulting coil is substantially insensitive to radiation and may be operated continuously in high radiation environments for long periods of time.

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

NASA Technical Reports Server (NTRS)

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.

Technology Solutions Case Study: Excavationless: Exterior-Side Foundation Insulation for Existing Homes

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Building science research supports installing exterior (soil side) foundation insulation as the optimal method to enhance the hygrothermal performance of new homes. With exterior foundation insulation, water management strategies are maximized while insulating the basement space and ensuring a more even temperature at the foundation wall. This project describes an innovative, minimally invasive foundation insulation upgrade technique on an existing home that uses hydrovac excavation technology combined with a liquid insulating foam. Cost savings over the traditional excavation process ranged from 23% to 50%. The excavationless process could result in even greater savings since replacement of building structures, exterior features,more » utility meters, and landscaping would be minimal or non-existent in an excavationless process.« less

Mechanical Attachment of Reusable Surface Insulation to Space Shuttle Primary Structure

NASA Technical Reports Server (NTRS)

Fleck, R. W.; Lehman, J. K.

1973-01-01

Three methods of attaching surface insulation tiles to shuttle primary structure have been proposed: direct bond, mechanical attachment, and subpanels with standoffs. The direct bond approach is lightweight but is difficult to refurbish and inspect. The subpanel approach is heavier but allows for easy refurbishment since subpanels are easily removed and replaced. The mechanical attachment approach allows easy refurbishment and inspection and is lightweight when an efficient insulator is used between surface insulation tiles and primary structure.

Silicon carbide sewing thread

NASA Technical Reports Server (NTRS)

Sawko, Paul M. (Inventor)

1995-01-01

Composite flexible multilayer insulation systems (MLI) were evaluated for thermal performance and compared with currently used fibrous silica (baseline) insulation system. The systems described are multilayer insulations consisting of alternating layers of metal foil and scrim ceramic cloth or vacuum metallized polymeric films quilted together using ceramic thread. A silicon carbide thread for use in the quilting and the method of making it are also described. These systems provide lightweight thermal insulation for a variety of uses, particularly on the surface of aerospace vehicles subject to very high temperatures during flight.

Improved Method of Locating Defects in Wiring Insulation

NASA Technical Reports Server (NTRS)

Greulich, Owen R.

2004-01-01

An improved method of locating small breaches in insulation on electrical wires combines aspects of the prior dielectric withstand voltage (DWV) and time-domain reflectometry (TDR) methods. The method was invented to satisfy a need for reliably and quickly locating insulation defects in spacecraft, aircraft, ships, and other complex systems that contain large amounts of wiring, much of it enclosed in structures that make it difficult to inspect. In the DWV method, one applies a predetermined potential (usually 1.5 kV DC) to the wiring and notes whether the voltage causes any arcing between the wiring and ground. The DWV method does not provide an indication of the location of the defect (unless, in an exceptional case, the arc happens to be visible). In addition, if there is no electrically conductive component at ground potential within about 0.010 in. (approximately equal to 0.254 mm) of the wire at the location of an insulation defect, then the DWV method does not provide an indication of the defect. Moreover, one does not have the option to raise the potential in an effort to increase the detectability of such a defect because doing so can harm previously undamaged insulation. In the TDR method as practiced heretofore, one applies a pulse of electricity having an amplitude of less than 25 V to a wire and measures the round-trip travel time for the reflection of the pulse from a defect. The distance along the wire from the point of application of the pulse to the defect is then calculated as the product of half the round-trip travel time and the characteristic speed of a propagation of an electromagnetic signal in the wire. While the TDR method as practiced heretofore can be used to locate a short or open circuit, it does not ordinarily enable one to locate a small breach in insulation because the pulse voltage is too low to cause arcing and thus too low to induce an impedance discontinuity large enough to generate a measurable reflection. The present improved method overcomes the weaknesses of both the prior DWV and the prior TDR method.

Photovoltaic energy technologies: Health and environmental effects document

NASA Astrophysics Data System (ADS)

Moskowitz, P. D.; Hamilton, L. D.; Morris, S. C.; Rowe, M. D.

1980-09-01

The potential health and environmental consequences of producing electricity by photovoltaic energy systems was analyzed. Potential health and environmental risks are identified in representative fuel and material supply cycles including extraction, processing, refining, fabrication, installation, operation, and isposal for four photovoltaic energy systems (silicon N/P single crystal, silicon metal/insulator/semiconductor (MIS) cell, cadmium sulfide/copper sulfide backwall cell, and gallium arsenide heterojunction cell) delivering equal amounts of useful energy. Each step of the fuel and material supply cycles, materials demands, byproducts, public health, occupational health, and environmental hazards is identified.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Methods for locating ground faults and insulation degradation condition in energy conversion systems

DOEpatents

Agamy, Mohamed; Elasser, Ahmed; Galbraith, Anthony William; Harfman Todorovic, Maja

2015-08-11

Methods for determining a ground fault or insulation degradation condition within energy conversion systems are described. A method for determining a ground fault within an energy conversion system may include, in part, a comparison of baseline waveform of differential current to a waveform of differential current during operation for a plurality of DC current carrying conductors in an energy conversion system. A method for determining insulation degradation within an energy conversion system may include, in part, a comparison of baseline frequency spectra of differential current to a frequency spectra of differential current transient at start-up for a plurality of DC current carrying conductors in an energy conversion system. In one embodiment, the energy conversion system may be a photovoltaic system.

Designing and Implementation a Lab Testing Method for Power Cables Insulation Resistance According with STAS 10411-89, SR EN ISO/CEI/17025/2005

NASA Astrophysics Data System (ADS)

Dobra, R.; Pasculescu, D.; Marc, G.; Risteiu, M.; Antonov, A.

2017-06-01

Insulation resistance measurement is one of the most important tests required by standards and regulations in terms of electrical safety. Why these tests are is to prevent possible accidents caused by electric shock, damage to equipment or outbreak of fire in normal operating conditions of electrical cables. The insulation resistance experiment refers to the testing of electrical cable insulation, which has a measured resistance that must be below the imposed regulations. Using a microcontroller system data regarding the insulation resistance of the power cables is acquired and with SCADA software the test results are displayed.

Superconductor-insulator transition and Fermi-Bose crossovers

DOE PAGES

Loh, Yen Lee; Randeria, Mohit; Trivedi, Nandini; ...

2016-05-31

The direct transition from an insulator to a superconductor (SC) in Fermi systems is a problem of long-standing interest, which necessarily goes beyond the standard BCS paradigm of superconductivity as a Fermi surface instability. We introduce here a simple, translationally invariant lattice fermion model that undergoes a SC-insulator transition (SIT) and elucidate its properties using analytical methods and quantum Monte Carlo simulations. We show that there is a fermionic band insulator to bosonic insulator crossover in the insulating phase and a BCS-to-BEC crossover in the SC. The SIT is always found to be from a bosonic insulator to a BEC-likemore » SC, with an energy gap for fermions that remains finite across the SIT. Hence, the energy scales that go critical at the SIT are the gap to pair excitations in the insulator and the superfluid stiffness in the SC. In addition to giving insight into important questions about the SIT in solid-state systems, our model should be experimentally realizable using ultracold fermions in optical lattices.« less

Thermal insulation and SIDS-an investigation of selected 'Eastern' and 'Western' infant bedding combinations.

PubMed

Wilson, C A; Chu, M S

2005-08-01

Differences in the incidence of SIDS between 'Western' and 'Eastern' countries has been attributed to cultural practices, which may affect the infants care and thermal environment. The purpose of this work was to estimate for selected 'commonly' used bedding, sleep positions and practices in Japan, Korea and New Zealand, the intrinsic 'dry' thermal resistance of bedding. Insulation levels are also discussed in the context of published information about the thermal environment in which the bedding is likely to be used. Selected Japanese, Korean and New Zealand bedding was loosely tucked over an infant manikin in the lateral, prone and supine sleep positions. Thickness in use was measured, and intrinsic 'dry' thermal resistance estimated using the Wilson Laing model which accommodates the effect on insulation of the three-dimensional arrangement of bedding combinations during use. Thickness of under- and upper-bedding varied among countries with thickness and estimated 'dry' thermal resistance of the upper-bedding affected by the type/combination of bedding and the infants sleep position. Insulation levels are discussed in relation to environmental conditions within and among countries and between seasons. Further information on thermal environments, bedding combinations used and care practices within both Asian and Western countries is needed. 'Eastern' infants appear likely to be generally covered in bedding combinations of greater insulation than those used to cover 'Western' infants in comparable seasons. Differences existed between insulation of the Japanese and Korean bedding combinations investigated. Lower rates of SIDS apparent in 'Asian' populations do not appear attributable to use of lower levels of bedding insulation only.

Surface structural changes of naturally aged silicone and EPDM composite insulators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vlastos, A.E.; Gubanski, S.M.

1991-04-01

In a long-term outdoor test with high direct and alternating voltages, silicone and EPDM rubber composite insulators have, at the beginning, shown a superior performance to that of glass and porcelain insulators. In the long-term test, however, the silicone rubber composite insulator has, in spite of the ageing of both insulator types, kept its good performance, while the performance of the EPDM rubber composite insulator was drastically deteriorated. In order to get a better insight into results obtained, the wettability and the surface structural changes of the insulators were studied by the drop deposition method (using a goniometer) and bymore » advanced techniques such as SEM, ESCA, FTIR and SIMS respectively. The results show that the differences in performance have to be found in the differences in the surface structural changes and in the dynamic ability of the surface to compensate the ageing.« less

SF6-alternative gases for application in gas-insulated switchgear

NASA Astrophysics Data System (ADS)

Li, Xingwen; Zhao, Hu; Murphy, Anthony B.

2018-04-01

The environmental problems caused by greenhouse gases have received unprecedented attention. Sulfur hexafluoride (SF6), which is the preferred gas for use in gas-insulated switchgear (circuit breakers, disconnect switches, etc. for high-voltage electrical circuits), has a very high global warming potential, and there is a large international effort to find alternative gases. Recently, this effort has made important progress, with promising alternative gases being identified and tested. An overview, in particular the current state of the art, of the study of SF6-alternative gases is presented in the paper. The review focuses on the application of the SF6-alternative gases in gas-insulated switchgear, with detailed analysis of calculations and measurements of their basic physical properties, dielectric strengths, and arc-quenching capabilities. Finally, a discussion of and perspectives on current research and future research directions are presented.

Comparison of Classical and Charge Storage Methods for Determining Conductivity of Thin Film Insulators

NASA Technical Reports Server (NTRS)

Swaminathan, Prasanna; Dennison, J. R.; Sim, Alec; Brunson, Jerilyn; Crapo, Eric; Frederickson, A. R.

2004-01-01

Conductivity of insulating materials is a key parameter to determine how accumulated charge will distribute across the spacecraft and how rapidly charge imbalance will dissipate. Classical ASTM and IEC methods to measure thin film insulator conductivity apply a constant voltage to two electrodes around the sample and measure the resulting current for tens of minutes. However, conductivity is more appropriately measured for spacecraft charging applications as the "decay" of charge deposited on the surface of an insulator. Charge decay methods expose one side of the insulator in vacuum to sequences of charged particles, light, and plasma, with a metal electrode attached to the other side of the insulator. Data are obtained by capacitive coupling to measure both the resulting voltage on the open surface and emission of electrons from the exposed surface, as well monitoring currents to the electrode. Instrumentation for both classical and charge storage decay methods has been developed and tested at Jet Propulsion Laboratory (JPL) and at Utah State University (USU). Details of the apparatus, test methods and data analysis are given here. The JPL charge storage decay chamber is a first-generation instrument, designed to make detailed measurements on only three to five samples at a time. Because samples must typically be tested for over a month, a second-generation high sample throughput charge storage decay chamber was developed at USU with the capability of testing up to 32 samples simultaneously. Details are provided about the instrumentation to measure surface charge and current; for charge deposition apparatus and control; the sample holders to properly isolate the mounted samples; the sample carousel to rotate samples into place; the control of the sample environment including sample vacuum, ambient gas, and sample temperature; and the computer control and data acquisition systems. Measurements are compared here for a number of thin film insulators using both methods at both facilities. We have found that conductivity determined from charge storage decay methods is 102 to 104 larger than values obtained from classical methods. Another Spacecraft Charging Conference presentation describes more extensive measurements made with these apparatus. This work is supported through funding from the NASA Space Environments and Effects Program and the USU Space Dynamics Laboratory Enabling Technologies Program.

The Ars insulator facilitates I-SceI meganuclease-mediated transgenesis in the sea urchin embryo.

PubMed

Ochiai, Hiroshi; Sakamoto, Naoaki; Suzuki, Kenichi; Akasaka, Koji; Yamamoto, Takashi

2008-09-01

For the efficient generation of transgenic sea urchins, we have adopted an I-SceI meganuclease-mediated transgenesis method. Several types of promoter-GFP gene constructs flanked by two I-SceI recognition sequences were co-injected with I-SceI into sea urchin fertilized eggs. Using cell-lineage-specific promoter constructs, the frequency of transgene expression was elevated, and their level of mozaicism was reduced. The addition of the Ars insulator sequence, which is known to block the enhancer activity and protect transgenes from position effects, led to a reduction in ectopic transgene expression and an elevation of transgene expression frequency in this I-SceI-mediated system. However, the magnitude of the effects of the Ars insulator was dependent upon the promoter constructs. QPCR analysis also showed that the Ars insulator increases the transgene copy number. These results suggest that the I-SceI-mediated method using the Ars insulator is advantageous for transgenesis in the sea urchin embryo.

Sound source measurement by using a passive sound insulation and a statistical approach

NASA Astrophysics Data System (ADS)

Dragonetti, Raffaele; Di Filippo, Sabato; Mercogliano, Francesco; Romano, Rosario A.

2015-10-01

This paper describes a measurement technique developed by the authors that allows carrying out acoustic measurements inside noisy environments reducing background noise effects. The proposed method is based on the integration of a traditional passive noise insulation system with a statistical approach. The latter is applied to signals picked up by usual sensors (microphones and accelerometers) equipping the passive sound insulation system. The statistical approach allows improving of the sound insulation given only by the passive sound insulation system at low frequency. The developed measurement technique has been validated by means of numerical simulations and measurements carried out inside a real noisy environment. For the case-studies here reported, an average improvement of about 10 dB has been obtained in a frequency range up to about 250 Hz. Considerations on the lower sound pressure level that can be measured by applying the proposed method and the measurement error related to its application are reported as well.

Identifying Two-Dimensional Z 2 Antiferromagnetic Topological Insulators

NASA Astrophysics Data System (ADS)

Bègue, F.; Pujol, P.; Ramazashvili, R.

2018-01-01

We revisit the question of whether a two-dimensional topological insulator may arise in a commensurate Néel antiferromagnet, where staggered magnetization breaks the symmetry with respect to both elementary translation and time reversal, but retains their product as a symmetry. In contrast to the so-called Z 2 topological insulators, an exhaustive characterization of antiferromagnetic topological phases with the help of topological invariants has been missing. We analyze a simple model of an antiferromagnetic topological insulator and chart its phase diagram, using a recently proposed criterion for centrosymmetric systems [13]. We then adapt two methods, originally designed for paramagnetic systems, and make antiferromagnetic topological phases manifest. The proposed methods apply far beyond the particular examples treated in this work, and admit straightforward generalization. We illustrate this by two examples of non-centrosymmetric systems, where no simple criteria have been known to identify topological phases. We also present, for some cases, an explicit construction of edge states in an antiferromagnetic topological insulator.

Thermocouple assembly

DOEpatents

Thermos, Anthony Constantine; Rahal, Fadi Elias

2002-01-01

A thermocouple assembly includes a thermocouple; a plurality of lead wires extending from the thermocouple; an insulating jacket extending along and enclosing the plurality of leads; and at least one internally sealed area within the insulating jacket to prevent fluid leakage along and within the insulating jacket. The invention also provides a method of preventing leakage of a fluid along and through an insulating jacket of a thermocouple including the steps of a) attaching a plurality of lead wires to a thermocouple; b) adding a heat sensitive pseudo-wire to extend along the plurality of lead wires; c) enclosing the lead wires and pseudo-wire inside an insulating jacket; d) locally heating axially spaced portions of the insulating jacket to a temperature which melts the pseudo-wire and fuses it with an interior surface of the jacket.

Automatic identification and location technology of glass insulator self-shattering

NASA Astrophysics Data System (ADS)

Huang, Xinbo; Zhang, Huiying; Zhang, Ye

2017-11-01

The insulator of transmission lines is one of the most important infrastructures, which is vital to ensure the safe operation of transmission lines under complex and harsh operating conditions. The glass insulator often self-shatters but the available identification methods are inefficient and unreliable. Then, an automatic identification and localization technology of self-shattered glass insulators is proposed, which consists of the cameras installed on the tower video monitoring devices or the unmanned aerial vehicles, the 4G/OPGW network, and the monitoring center, where the identification and localization algorithm is embedded into the expert software. First, the images of insulators are captured by cameras, which are processed to identify the region of insulator string by the presented identification algorithm of insulator string. Second, according to the characteristics of the insulator string image, a mathematical model of the insulator string is established to estimate the direction and the length of the sliding blocks. Third, local binary pattern histograms of the template and the sliding block are extracted, by which the self-shattered insulator can be recognized and located. Finally, a series of experiments is fulfilled to verify the effectiveness of the algorithm. For single insulator images, Ac, Pr, and Rc of the algorithm are 94.5%, 92.38%, and 96.78%, respectively. For double insulator images, Ac, Pr, and Rc are 90.00%, 86.36%, and 93.23%, respectively.

Expert Meeting Report. Interior Insulation Retrofit of Mass Masonry Wall Assemblies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ueno, K.; Van Straaten, R.

2012-02-01

The Building Science Consortium held an Expert Meeting on Interior Insulation Retrofit of Mass Masonry Wall Assemblies on July 30, 2011, at the Westford Regency Hotel in Westford, MA. This report outlines the extensive information that was presented on assessment of risk factors for premature building deterioration due to interior insulation retrofits, and methods to reduce such risks.

Expert Meeting Report: Interior Insulation Retrofit of Mass Masonry Wall Assemblies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ueno, K.; Van Straaten, R.

2012-02-01

The Building Science Consortium held an Expert Meeting on Interior Insulation Retrofit of Mass Masonry Wall Assemblies on July 30, 2011 at the Westford Regency Hotel in Westford, MA. This report outlines the extensive information that was presented on assessment of risk factors for premature building deterioration due to interior insulation retrofits, and methods to reduce such risks.

WSTF electrical arc projects

NASA Technical Reports Server (NTRS)

Linley, Larry

1994-01-01

The objectives of these projects include the following: validate method used to screen wire insulation with arc tracking characteristics; determine damage resistance to arc as a function of source voltage and insulation thickness; investigate propagation characteristics of Kapton at low voltages; and investigate pyrolytic properties of polyimide insulated (Kapton) wire for low voltage (less than 35 VDC) applications. Supporting diagrams and tables are presented.

Synthesis of temperature and solvent-resistant polymers

NASA Technical Reports Server (NTRS)

Webster, J. A.; Patterson, W. J.; Moffett, R. L.; Morris, D. E.

1972-01-01

Development of silicone polymers, polyimides, and polyisocyanurates for use as insulation, coatings, or adhesives under adverse environmental conditions is discussed. Chemical structure of the organic compounds is presented. Physical and mechanical properties of the compounds are analyzed.

KSC-2010-1110

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, one of the walls of the Propellants North Administrative and Maintenance Facility is lowered into the trench which will support it. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2009-6799

NASA Image and Video Library

2009-12-11

CAPE CANAVERAL, Fla. - Construction of the walls for the Propellants North Administrative and Maintenance Facility begins in Launch Complex 39 at NASA's Kennedy Space Center in Florida. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1109

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, workers guide one of the walls of the Propellants North Administrative and Maintenance Facility into place. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1120

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, the final shape of the Propellants North Administrative and Maintenance Facility becomes apparent as its walls are erected. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1117

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, a team of construction workers ensures that the walls of the Propellants North Administrative and Maintenance Facility are installed properly. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1115

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, a crane is enlisted to lift the walls of the Propellants North Administrative and Maintenance Facility into position. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1112

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, the Propellants North Administrative and Maintenance Facility begins to take shape as its walls are lifted into position. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1111

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, the Propellants North Administrative and Maintenance Facility begins to take shape as its walls are lifted into position. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1108

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, one of the walls of the Propellants North Administrative and Maintenance Facility glides through the air into position. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1118

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, a row of walls is erected as the Propellants North Administrative and Maintenance Facility takes shape. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1121

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, reminiscent of a barn-raising, the Propellants North Administrative and Maintenance Facility springs into being in a single day as its walls are lifted into position. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1119

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, steady progress is made by a team of construction workers to erect the walls of the Propellants North Administrative and Maintenance Facility. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1107

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, workers lift one of the walls of the Propellants North Administrative and Maintenance Facility into an upright position. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1106

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, the first wall of the Propellants North Administrative and Maintenance Facility is lifted into place. In the background is the 525-foot-tall Vehicle Assembly Building. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1116

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, man and machine work side by side to position the walls of the Propellants North Administrative and Maintenance Facility. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

KSC-2010-1113

NASA Image and Video Library

2010-01-07

CAPE CANAVERAL, Fla. - In Launch Complex 39 at NASA's Kennedy Space Center in Florida, a worker is seen through an opening left for a doorway in a newly erected wall of the Propellants North Administrative and Maintenance Facility. A tilt-up construction method is being used to erect a THERMOMASS concrete wall insulation system for the facility's walls. In this approach, the exterior layer of concrete for the wall panels is poured and leveled on the building's footprint. Then, prefabricated, predrilled insulation sheets are arranged on top of the unhardened concrete, and connectors, designed to hold the sandwiched layers of concrete and insulation secure, are inserted through the predrilled holes. Next, the structural wythe is poured. Once cured, these panels are lifted upright to form the building's envelope. The facility will have a two-story administrative building to house managers, mechanics and technicians who fuel spacecraft at Kennedy adjacent to an 1,800-square-foot single-story shop to store cryogenic fuel transfer equipment. The new facility will feature high-efficiency roofs and walls, “Cool Dry Quiet” air conditioning with energy recovery technology, efficient lighting, and other sustainable features. The facility is striving to qualify for the U.S. Green Building Council’s Leadership in Energy and Environmental Design, or LEED, Platinum certification. If successful, Propellants North will be the first Kennedy facility to achieve this highest of LEED ratings after it is completed in the summer of 2010. The facility was designed for NASA by Jones Edmunds and Associates. Photo credit: NASA/Jim Grossmann

Cladding Attachment Over Thick Exterior Insulating Sheathing (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of wood-framed walls and mass masonry wall assemblies. The location of the insulation on the exterior of the structure has many direct benefits, including better effective R-value from reduced thermal bridging, better condensation resistance, reduced thermal stress on the structure, as well as other commonly associated improvements such as increased airtightness and improved water management. For thick layers of exterior insulation (more than 1.5 in.), the use of wood furring strips attached through the insulation back to the structure has been usedmore » by many contractors and designers as a means to provide a convenient cladding attachment location. Although the approach has proven effective, there is significant resistance to its widespread implementation due to a lack of research and understanding of the mechanisms involved in the development of the vertical displacement resistance capacity. In addition, the long-term in-service performance of the system has been questioned due to potential creep effects of the assembly under the sustained dead load of the cladding and effects of varying environmental conditions. In addition, the current International Building Code (IBC) and International Residential Code (IRC) do not have a provision that specifically allows this assembly.« less

Experimental measurements and evaluation of the expanded water repellent perlite used for the cargo containment system of LNG carrier

NASA Astrophysics Data System (ADS)

Li, Manfeng; Ju, Yonglin

2017-10-01

To minimize the water absorption and to improve the thermal insulated properties of the insulation materials used for the cargo containment systems (CCSs) of LNG carrier, a kind of expanded water-repellent perlite has been developed by coating hydrophobic membrane onto the outer surface of the expanded perlite to change its physical and chemical characteristics. Considering the CCSs operated in a wide temperature range from environmental temperature to cryogenic temperature, the thermal analysis has been conducted to quantitatively determine the thermal insulted properties of the insulation materials. Furthermore, a double-sided guarded hot plate apparatus (GHP) is specifically designed and fabricated for the measurement of the thermal conductivities of the insulation specimens operated down to liquid nitrogen temperature. The breakage ratio associated with the water absorption and the thermal conductivity of the expanded water-repellent perlite is firstly proposed, and then a series of experiments are carried out to determine the thermal conductivity of the expanded water-repellent perlite ranging from room temperature to cryogenic temperature based on the different breakage ratios.

Thermal highly porous insulation materials made of mineral raw materials

NASA Astrophysics Data System (ADS)

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.

Optically detecting the edge-state of a three-dimensional topological insulator under ambient conditions by ultrafast infrared photoluminescence spectroscopy

PubMed Central

Maezawa, Shun-ya; Watanabe, Hiroshi; Takeda, Masahiro; Kuroda, Kenta; Someya, Takashi; Matsuda, Iwao; Suemoto, Tohru

2015-01-01

Ultrafast infrared photoluminescence spectroscopy was applied to a three-dimensional topological insulator TlBiSe2 under ambient conditions. The dynamics of the luminescence exhibited bulk-insulating and gapless characteristics bounded by the bulk band gap energy. The existence of the topologically protected surface state and the picosecond-order relaxation time of the surface carriers, which was distinguishable from the bulk response, were observed. Our results provide a practical method applicable to topological insulators under ambient conditions for device applications. PMID:26552784

High-Tech, Low-Temp Insulation

NASA Technical Reports Server (NTRS)

1998-01-01

Under an SBIR (Small Business Innovative Research) contract with Ames, S.D. Miller & Associates developed new manufacturing methods for multi-layer metal spacecraft insulation that could significantly reduce launch weight and launch costs. The new honeycomb structure is more efficient than fibers for insulation. Honeycombs can be made from metals for high temperature uses, even plastic insulation from recycled milk bottles. Under development are blankets made from recycled milk bottles which will be field tested by the Red Cross and ambulance companies. Currently available are honeycomb mittens based on the same technology.

The usefulness of mobile insulator sheets for the optimisation of deep heating area for regional hyperthermia using a capacitively coupled heating method: phantom, simulation and clinical prospective studies.

PubMed

Tomura, Kyosuke; Ohguri, Takayuki; Mulder, Hendrik Thijmen; Murakami, Motohiro; Nakahara, Sota; Yahara, Katsuya; Korogi, Yukunori

2017-11-20

To evaluate the feasibility and efficacy of deep regional hyperthermia with the use of mobile insulator sheets in a capacitively coupled heating device. The heat was applied using an 8-MHz radiofrequency-capacitive device. The insulator sheet was inserted between the regular bolus and cooled overlay bolus in each of upper and lower side of the electrode. Several settings using the insulator sheets were investigated in an experimental study using an agar phantom to evaluate the temperature distributions. The specific absorption rate (SAR) distributions in several organs were also computed for the three-dimensional patient model. In a clinical prospective study, a total of five heating sessions were scheduled for the pelvic tumours, to assess the thermal parameters. The conventional setting was used during the first, third and fifth treatment sessions, and insulator sheets were used during the second and fourth treatment sessions. In the phantom study, the higher heating area improved towards the centre when the mobile insulator sheets were used. The subcutaneous fat/target ratios for the averaged SARs in the setting with the mobile insulator (median, 2.5) were significantly improved compared with those in the conventional setting (median, 3.4). In the clinical study, the thermal dose parameters of CEM43°CT90 in the sessions with the mobile insulator sheets (median, 1.9 min) were significantly better than those in the sessions using a conventional setting (median, 1.0 min). Our novel heating method using mobile insulator sheets was thus found to improve the thermal dose parameters. Further investigations are expected.

Anisotropic fibrous thermal insulator of relatively thick cross section and method for making same

DOEpatents

Reynolds, Carl D.; Ardary, Zane L.

1979-01-01

The present invention is directed to an anisotropic thermal insulator formed of carbon-bonded organic or inorganic fibers and having a thickness or cross section greater than about 3 centimeters. Delaminations and deleterious internal stresses generated during binder curing and carbonizing operations employed in the fabrication of thick fibrous insulation of thicknesses greater than 3 centimeters are essentially obviated by the method of the present invention. A slurry of fibers, thermosetting resin binder and water is vacuum molded into the selected insulator configuration with the total thickness of the molded slurry being less than about 3 centimeters, the binder is thermoset to join the fibers together at their nexaes, and then the binder is carbonized to form the carbon bond. A second slurry of the fibers, binder and water is then applied over the carbonized body with the vacuum molding, binder thermosetting and carbonizing steps being repeated to form a layered insulator with the binder providing a carbon bond between the layers. The molding, thermosetting and carbonizing steps may be repeated with additional slurries until the thermal insulator is of the desired final thickness. An additional feature of the present invention is provided by incorporating opacifying materials in any of the desired layers so as to provide different insulating properties at various temperatures. Concentration and/or type of additive can be varied from layer-to-layer.

A Novel Method for Measuring Electrical Conductivity of High Insulating Oil Using Charge Decay

NASA Astrophysics Data System (ADS)

Wang, Z. Q.; Qi, P.; Wang, D. S.; Wang, Y. D.; Zhou, W.

2016-05-01

For the high insulating oil, it is difficult to measure the conductivity precisely using voltammetry method. A high-precision measurementis proposed for measuring bulk electrical conductivity of high insulating oils (about 10-9--10-15S/m) using charge decay. The oil is insulated and charged firstly, and then grounded fully. During the experimental procedure, charge decay is observed to show an exponential law according to "Ohm" theory. The data of time dependence of charge density is automatically recorded using an ADAS and a computer. Relaxation time constant is fitted from the data using Gnuplot software. The electrical conductivity is calculated using relaxation time constant and dielectric permittivity. Charge density is substituted by electric potential, considering charge density is difficult to measure. The conductivity of five kinds of oils is measured. Using this method, the conductivity of diesel oil is easily measured to beas low as 0.961 pS/m, as shown in Fig. 5.

Analysis of the error of the developed method of determination the active conductivity reducing the insulation level between one phase of the network and ground, and insulation parameters in a non-symmetric network with isolated neutral with voltage above 1000 V

NASA Astrophysics Data System (ADS)

Utegulov, B. B.

2018-02-01

In the work the study of the developed method was carried out for reliability by analyzing the error in indirect determination of the insulation parameters in an asymmetric network with an isolated neutral voltage above 1000 V. The conducted studies of the random relative mean square errors show that the accuracy of indirect measurements in the developed method can be effectively regulated not only by selecting a capacitive additional conductivity, which are connected between phases of the electrical network and the ground, but also by the selection of measuring instruments according to the accuracy class. When choosing meters with accuracy class of 0.5 with the correct selection of capacitive additional conductivity that are connected between the phases of the electrical network and the ground, the errors in measuring the insulation parameters will not exceed 10%.

Dielectric properties of highly resistive GaN crystals grown by ammonothermal method at microwave frequencies

NASA Astrophysics Data System (ADS)

Krupka, Jerzy; Zajåc, Marcin; Kucharski, Robert; Gryglewski, Daniel

2016-03-01

Permittivity, the dielectric loss tangent and conductivity of semi-insulating Gallium Nitride crystals have been measured as functions of frequency from 10 GHz to 50 GHz and temperature from 295 to 560 K employing quasi TE0np mode dielectric resonator technique. Crystals were grown using ammonothermal method. Two kinds of doping were used to obtain high resistivity crystals; one with deep acceptors in form of transition metal ions, and the other with shallow Mg acceptors. The sample compensated with transition metal ions exhibited semi-insulating behavior in the whole temperature range. The sample doped with Mg acceptors remained semi-insulating up to 390 K. At temperatures exceeding 390 K the conductivity term in the total dielectric loss tangent of Mg compensated sample becomes dominant and it increases exponentially with activation energy of 1.14 eV. It has been proved that ammonothermal method with appropriate doping allows growth of high quality, temperature stable semi-insulating GaN crystals.

Effects of hierarchical structures and insulating liquid media on adhesion

NASA Astrophysics Data System (ADS)

Yang, Weixu; Wang, Xiaoli; Li, Hanqing; Song, Xintao

2017-11-01

Effects of hierarchical structures and insulating liquid media on adhesion are investigated through a numerical adhesive contact model established in this paper, in which hierarchical structures are considered by introducing the height distribution into the surface gap equation, and media are taken into account through the Hamaker constant in Lifshitz-Hamaker approach. Computational methods such as inexact Newton method, bi-conjugate stabilized (Bi-CGSTAB) method and fast Fourier transform (FFT) technique are employed to obtain the adhesive force. It is shown that hierarchical structured surface exhibits excellent anti-adhesive properties compared with flat, micro or nano structured surfaces. Adhesion force is more dependent on the sizes of nanostructures than those of microstructures, and the optimal ranges of nanostructure pitch and maximum height for small adhesion force are presented. Insulating liquid media effectively decrease the adhesive interaction and 1-bromonaphthalene exhibits the smallest adhesion force among the five selected media. In addition, effects of hierarchical structures with optimal sizes on reducing adhesion are more obvious than those of the selected insulating liquid media.

Micropatterning of poly(dimethylsiloxane) using a photoresist lift-off technique for selective electrical insulation of microelectrode arrays

PubMed Central

Park, Jaewon; Kim, Hyun Soo; Han, Arum

2009-01-01

A poly(dimethylsiloxane) (PDMS) patterning method based on a photoresist lift-off technique to make an electrical insulation layer with selective openings is presented. The method enables creating PDMS patterns with small features and various thicknesses without any limitation in the designs and without the need for complicated processes or expensive equipments. Patterned PDMS layers were created by spin-coating liquid phase PDMS on top of a substrate having sacrificial photoresist patterns, followed by a photoresist lift-off process. The thickness of the patterned PDMS layers could be accurately controlled (6.5–24 µm) by adjusting processing parameters such as PDMS spin-coating speeds, PDMS dilution ratios, and sacrificial photoresist thicknesses. PDMS features as small as 15 µm were successfully patterned and the effects of each processing parameter on the final patterns were investigated. Electrical resistance tests between adjacent electrodes with and without the insulation layer showed that the patterned PDMS layer functions properly as an electrical insulation layer. Biocompatibility of the patterned PDMS layer was confirmed by culturing primary neuron cells on top of the layer for up to two weeks. An extensive neuronal network was successfully formed, showing that this PDMS patterning method can be applied to various biosensing microdevices. The utility of this fabrication method was further demonstrated by successfully creating a patterned electrical insulation layer on flexible substrates containing multi-electrode arrays. PMID:19946385

Determination of copper in liquid and solid insulation for large electrical equipment by ICP-OES. Application to copper contamination assessment in power transformers.

PubMed

Bruzzoniti, Maria Concetta; De Carlo, Rosa Maria; Sarzanini, Corrado; Maina, Riccardo; Tumiatti, Vander

2012-09-15

Copper is one of the main constituents of the components in power transformers and its presence both in liquid (mineral oil) and in solid (Kraft paper) insulators can lead to enhanced dielectric losses and to the subsequent deterioration of their insulating properties. Recently the latter have been correlated to plant failures which in turn may have severe impact on the environment. This paper describes the direct analysis of copper in insulating mineral oil by ICP-OES and how it was first optimized compared to the official American Society for Testing and Materials (ASTM) D7151 method. Detection and quantification limits of 8.8 μg kg(-1) and 29.3 μg kg(-1) were obtained. Secondly, copper determination was improved by coupling a microwave assisted dissolution procedure of the mineral oil which avoided the problems, in the real samples, due to the presence of solid species of copper which cannot be nebulized following traditional methods described in literature. Sixteen mineral insulating oils sampled from transformers in service were analyzed before and after dissolution. In order to evaluate copper speciation, size fractionation was performed by filtration on PTFE filters (0.45, 1 and 5 μm). This test was performed on all the oil samples. Finally, because of the key role of the solid insulator in failed transformers, the Authors applied the developed method to study the copper deposition tendency onto the insulating Kraft paper tapes exerted by two unused oils (a corrosive and a non-corrosive one) under defined ageing conditions. Copyright © 2012 Elsevier B.V. All rights reserved.

The Structural Heat Intercept-Insulation-Vibration Evaluation Rig (SHIVER)

NASA Technical Reports Server (NTRS)

Johnson, W. L.; Zoeckler, J. G.; Best-Ameen, L. M.

2015-01-01

NASA is currently investigating methods to reduce the boil-off rate on large cryogenic upper stages. Two such methods to reduce the total heat load on existing upper stages are vapor cooling of the cryogenic tank support structure and integration of thick multilayer insulation systems to the upper stage of a launch vehicle. Previous efforts have flown a 2-layer MLI blanket and shown an improved thermal performance, and other efforts have ground-tested blankets up to 70 layers thick on tanks with diameters between 2 3 meters. However, thick multilayer insulation installation and testing in both thermal and structural modes has not been completed on a large scale tank. Similarly, multiple vapor cooled shields are common place on science payload helium dewars; however, minimal effort has gone into intercepting heat on large structural surfaces associated with rocket stages. A majority of the vapor cooling effort focuses on metallic cylinders called skirts, which are the most common structural components for launch vehicles. In order to provide test data for comparison with analytical models, a representative test tank is currently being designed to include skirt structural systems with integral vapor cooling. The tank is 4 m in diameter and 6.8 m tall to contain 5000 kg of liquid hydrogen. A multilayer insulation system will be designed to insulate the tank and structure while being installed in a representative manner that can be extended to tanks up to 10 meters in diameter. In order to prove that the insulation system and vapor cooling attachment methods are structurally sound, acoustic testing will also be performed on the system. The test tank with insulation and vapor cooled shield installed will be tested thermally in the B2 test facility at NASAs Plumbrook Station both before and after being vibration tested at Plumbrooks Space Power Facility.

Aerogel Insulation Applications for Liquid Hydrogen Launch Vehicle Tanks

NASA Technical Reports Server (NTRS)

Fesmire, J. E.; Sass, J.

2007-01-01

Aerogel based insulation systems for ambient pressure environments were developed for liquid hydrogen (LH2) tank applications. Solutions to thermal insulation problems were demonstrated for the Space Shuttle External Tank (ET) through extensive testing at the Cryogenics Test Laboratory. Demonstration testing was performed using a 1/10th scale ET LH2 intertank unit and liquid helium as the coolant to provide the 20 K cold boundary temperature. Cryopumping tests in the range of 20K were performed using both constant mass and constant pressure methods. Long-duration tests (up to 10 hours) showed that the nitrogen mass taken up inside the intertank is reduced by a factor of nearly three for the aerogel insulated case as compared to the un-insulated (bare metal flight configuration) case. Test results including thermal stabilization, heat transfer effectiveness, and cryopumping confirm that the aerogel system eliminates free liquid nitrogen within the intertank. Physisorption (or adsorption) of liquid nitrogen within the fine pore structure of aerogel materials was also investigated. Results of a mass uptake method show that the sorption ratio (liquid nitrogen to aerogel beads) is about 62 percent by volume. A novel liquid nitrogen production method of testing the liquid nitrogen physical adsorption capacity of aerogel beads was also performed to more closely approximate the actual launch vehicle cooldown and thermal stabilization effects within the aerogel material. The extraordinary insulating effectiveness of the aerogel material shows that cryopumping is not an open-cell mass transport issue but is strictly driven by thermal communication between warm and cold surfaces. The new aerogel insulation technology is useful to solve heat transfer problem areas and to augment existing thermal protection systems on launch vehicles. Examples are given and potential benefits for producing launch systems that are more reliable, robust, reusable, and efficient are outlined.

Observation of Topological Links Associated with Hopf Insulators in a Solid-State Quantum Simulator

NASA Astrophysics Data System (ADS)

Yuan, X.-X.; He, L.; Wang, S.-T.; Deng, D.-L.; Wang, F.; Lian, W.-Q.; Wang, X.; Zhang, C.-H.; Zhang, H.-L.; Chang, X.-Y.; Duan, L.-M.

2017-06-01

Hopf insulators are intriguing three-dimensional topological insulators characterized by an integer topological invariant. They originate from the mathematical theory of Hopf fibration and epitomize the deep connection between knot theory and topological phases of matter, which distinguishes them from other classes of topological insulators. Here, we implement a model Hamiltonian for Hopf insulators in a solid-state quantum simulator and report the first experimental observation of their topological properties, including fascinating topological links associated with the Hopf fibration and the integer-valued topological invariant obtained from a direct tomographic measurement. Our observation of topological links and Hopf fibration in a quantum simulator opens the door to probe rich topological properties of Hopf insulators in experiments. The quantum simulation and probing methods are also applicable to the study of other intricate three-dimensional topological model Hamiltonians.

Inspecting cracks in foam insulation

NASA Technical Reports Server (NTRS)

Cambell, L. W.; Jung, G. K.

1979-01-01

Dye solution indicates extent of cracking by penetrating crack and showing original crack depth clearly. Solution comprised of methylene blue in denatured ethyl alcohol penetrates cracks completely and evaporates quickly and is suitable technique for usage in environmental or structural tests.

Measure Guideline: Installing Rigid Foam Insulation on the Interior of Existing Brick Walls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Natarajan, H.; Klocke, S.; Puttagunta, S.

2012-06-01

This measure guideline provides information on an effective method to insulate the interior of existing brick masonry walls with extruded polystyrene (XPS) insulation board. The guide outlines step-by-step design and installation procedures while explaining the benefits and tradeoffs where applicable. The authors intend that this document be useful to a varied audience that includes builders, remodelers, contractors and homeowners.

Measure Guideline. Installing Rigid Foam Insulation on the Interior of Existing Brick Walls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Natarajan, Hariharan; Klocke, Steve; Puttagunta, Srikanth

2012-06-01

This measure guideline provides information on an effective method to insulate the interior of existing brick masonry walls with extruded polystyrene (XPS) insulation board. The guide outlines step-by-step design and installation procedures while explaining the benefits and tradeoffs where applicable. The authors intend that this document be useful to a varied audience that includes builders,remodelers, contractors and homeowners.

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

NASA Technical Reports Server (NTRS)

1973-01-01

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

Systems and methods for the magnetic insulation of accelerator electrodes in electrostatic accelerators

DOEpatents

Grisham, Larry R

2013-12-17

The present invention provides systems and methods for the magnetic insulation of accelerator electrodes in electrostatic accelerators. Advantageously, the systems and methods of the present invention improve the practically obtainable performance of these electrostatic accelerators by addressing, among other things, voltage holding problems and conditioning issues. The problems and issues are addressed by flowing electric currents along these accelerator electrodes to produce magnetic fields that envelope the accelerator electrodes and their support structures, so as to prevent very low energy electrons from leaving the surfaces of the accelerator electrodes and subsequently picking up energy from the surrounding electric field. In various applications, this magnetic insulation must only produce modest gains in voltage holding capability to represent a significant achievement.

Tunnel Magneto Resistance of Fe/Insulator/Fe

NASA Astrophysics Data System (ADS)

Aryee, Dennis; Seifu, Dereje

Tri-layer thin films of Fe/Insulator/Fe were synthesized using magnetron DC/ RF sputtering with MgO insulator and Bi2Te3 topological insulators as middle buffer layer. The multi-layered samples thus produced were studied using in-house built magneto-optic Kerr effect (MOKE) instrument, vibrating sample magnetometer (VSM), torque magnetometer (TMM), AFM, MFM, and magneto-resistance (MR). This system, that is Fe/Insulator/Fe on MgO(100) substrate, is a well-known tunnel magneto resistance (TMR) structure often used in magnetic tunnel junction (MTJ) devices. TMR effect is a method by which MTJs are used in developing magneto-resistive random access memory (MRAM), magnetic sensors, and novel logic devices. The main purpose behind this research is to measure the magnetic anisotropy of Fe/Insulator /Fe structure and correlate it to magneto-resistance. In this presentation, we will present results from MOKE, VSM, TMM, AFM, MFM, and MR studies of Fe/Insulator/Fe on MgO(100). We would like to acknowledge support by NSF-MRI-DMR-1337339.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loh, Yen Lee; Randeria, Mohit; Trivedi, Nandini

The direct transition from an insulator to a superconductor (SC) in Fermi systems is a problem of long-standing interest, which necessarily goes beyond the standard BCS paradigm of superconductivity as a Fermi surface instability. We introduce here a simple, translationally invariant lattice fermion model that undergoes a SC-insulator transition (SIT) and elucidate its properties using analytical methods and quantum Monte Carlo simulations. We show that there is a fermionic band insulator to bosonic insulator crossover in the insulating phase and a BCS-to-BEC crossover in the SC. The SIT is always found to be from a bosonic insulator to a BEC-likemore » SC, with an energy gap for fermions that remains finite across the SIT. Hence, the energy scales that go critical at the SIT are the gap to pair excitations in the insulator and the superfluid stiffness in the SC. In addition to giving insight into important questions about the SIT in solid-state systems, our model should be experimentally realizable using ultracold fermions in optical lattices.« less

New Techniques to Evaluate the Incendiary Behavior of Insulators

NASA Technical Reports Server (NTRS)

Buhler, Charles; Calle, Carlos; Clements, Sid; Trigwell, Steve; Ritz, Mindy

2008-01-01

New techniques for evaluating the incendiary behavior of insulators is presented. The onset of incendive brush discharges in air is evaluated using standard spark probe techniques for the case simulating approaches of an electrically grounded sphere to a charged insulator in the presence of a flammable atmosphere. However, this standard technique is unsuitable for the case of brush discharges that may occur during the charging-separation process for two insulator materials. We present experimental techniques to evaluate this hazard in the presence of a flammable atmosphere which is ideally suited to measure the incendiary nature of micro-discharges upon separation, a measurement never before performed. Other measurement techniques unique to this study include; surface potential measurements of insulators before, during and after contact and separation, as well as methods to verify fieldmeter calibrations using a charge insulator surface opposed to standard high voltage plates. Key words: Kapton polyimide film, incendiary discharges, brush discharges, contact and frictional electrification, ignition hazards, insulators, contact angle, surface potential measurements.

A brief survey of radiation effects on polymer dielectrics

NASA Technical Reports Server (NTRS)

Laghari, Javaid R.; Hammoud, Ahmad N.

1990-01-01

Future space power needs are extrapolated to be at least three to four orders of magnitude more than is currently available. This long-term reliable power will be required on missions such as the Space Station, Pathfinder, Space Plane, and high-powered satellites, and for defense. Electrical insulation and dielectrics are the key electrical materials needed to support these power systems, where a single-point system failure could prove catastrophic or even fatal for the whole mission. Therefore, the impact of radiation, an environmental stress, on the properties and performance of insulation and dielectrics must be understood. The influence of radiation on polymer dielectrics, the insulating materials most commonly used for power transmission and storage, is reviewed. The effects of the type of radiation, dose, rate, and total exposure on the key electrical, mechanical, and physical properties of polymer dielectrics are described and explained.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-06-01

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

Energy and Environment 1990: Transportation-induced noise and air pollution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1990-01-01

Contents: public reaction to low levels of aircraft noise; airport noise insulation of homes surrounding stapleton international airport; sound insulation and thermal performance modifications: case study for three dwellings near bwi airport; single-number ratings for outdoor-indoor sound insulation; control of wheel squeal noise in rail transit cars; knowledge-based preprocessor for traffic noise prediction; barrier overlap analysis procedure; atmospheric effects on traffic noise propagation; predicting stop-and-go traffic noise with stamina 2.0; feasibility of transparent noise barriers; field testing of the effectiveness of open-graded asphalt pavement in reducing tire noise from highway vehicles; cost of noise barrier construction in the united states;more » comparisons of emissions of transit buses using methanol and diesel fuel; high-speed rail system noise assessment; energy-related, environmental, and economic benefits of florida's high-speed rail and maglev systems proposals.« less

International Conference on Environmental Ergonomics (4th) Held in Austin, Texas on 1-5 October 1990

DTIC Science & Technology

1991-01-15

measurement error in relation 94 Ducharme, Michel B. to clothing and tissue insulation -- a simplified view 5 Reischl, Uwe Breathability measurements...PROTECTIVE CLOTHING Uwe Reischl, Francis N. Dukes-Dobos, Thomas E. Bernard and Kai Buller Department of Environmental and Occupational Health 0 College of...understood. 117 BREATHING APPARATUS AND VENTILATION William P. Morgan Biodynamics Laboratory University of Wisconsin- Madison 0 Madison , Wisconsin USA

Talk to the Hand: U.S. Army Biophysical Testing.

PubMed

Santee, William R; Potter, Adam W; Friedl, Karl E

2017-07-01

Many people are unaware of the science underlying the biophysical properties of Soldier clothing and personal protective equipment, yet there is a well-refined biomedical methodology initiated by Army physiologists in World War II. This involves a methodical progression of systematic material testing technologies, computer modeling, and human testing that enables more efficient development and rapid evaluation of new concepts for Soldier health and performance. Sophisticated manikins that sweat and move are a central part of this testing continuum. This report briefly summarizes the evolution and use of one specialized form of the manikin technologies, the thermal hand model, and its use in research on Soldier hand-wear items that sustain dexterity and protect the hand in extreme environments. Thermal manikin testing methodologies were developed to provide an efficient and consistent analytical tool for the rapid evaluation of new clothing concepts. These methods have been upgraded since the original World War II and Korean War eras to include articulation and sweating capabilities, as characterized and illustrated in this article. The earlier "retired" versions of thermal hand models have now been transferred to the National Museum of Health and Science. The biophysical values from manikin testing are critical inputs to the U.S. Army Research Institute of Environmental Medicine mathematical models that provide predictions of soldier comfort, duration of exposure before loss of manual dexterity, and time to significant risk of freezing (skin temperature <-1°C) and nonfreezing cold injuries (skin temperature <5°C). The greater thickness of better insulated handwear reduces dexterity and also increases surface area which makes added insulation increasingly less effective in retaining heat. Measurements of both thermal resistance (insulation) and evaporative resistance (permeability) collectively characterize the biophysical properties and enable mathematical modeling of the human thermophysiological responses. This information can help guide the hand-wear development and selection process which often requires trade-offs between factors such as material, cost, and sizing. Soldier hands provide fine motor dexterity in tactical functions, ranging from pulling a trigger to pulling a parachute ripcord; thus, protecting hand function is critical to soldier readiness. Also, the importance of protection against nonbattle cold injuries was highlighted during World War II in northern Europe, in the Aleutian Islands, and later in Korea. The U.S. Army has been on the forefront of the biophysical analysis of clothing including gloves since environmental research was established at the Armored Medical Research Laboratory and Climatic Research Laboratory during World War II. U.S. Army Research Institute of Environmental Medicine does not make the equipment but works with their Natick Soldier Research, Development, and Engineering Center partners to make the equipment better. Reprint & Copyright © 2017 Association of Military Surgeons of the U.S.

Effect of Sweating on Insulation of Footwear.

PubMed

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.

Formation of multiple levels of porous silicon for buried insulators and conductors in silicon device technologies

DOEpatents

Blewer, Robert S.; Gullinger, Terry R.; Kelly, Michael J.; Tsao, Sylvia S.

1991-01-01

A method of forming a multiple level porous silicon substrate for semiconductor integrated circuits including anodizing non-porous silicon layers of a multi-layer silicon substrate to form multiple levels of porous silicon. At least one porous silicon layer is then oxidized to form an insulating layer and at least one other layer of porous silicon beneath the insulating layer is metallized to form a buried conductive layer. Preferably the insulating layer and conductive layer are separated by an anodization barrier formed of non-porous silicon. By etching through the anodization barrier and subsequently forming a metallized conductive layer, a fully or partially insulated buried conductor may be fabricated under single crystal silicon.

The effect of nanoparticle surfactant polarization on trapping depth of vegetable insulating oil-based nanofluids

NASA Astrophysics Data System (ADS)

Li, Jian; Du, Bin; Wang, Feipeng; Yao, Wei; Yao, Shuhan

2016-02-01

Nanoparticles can generate charge carrier trapping and reduce the velocity of streamer development in insulating oils ultimately leading to an enhancement of the breakdown voltage of insulating oils. Vegetable insulating oil-based nanofluids with three sizes of monodispersed Fe3O4 nanoparticles were prepared and their trapping depths were measured by thermally stimulated method (TSC). It is found that the nanoparticle surfactant polarization can significantly influence the trapping depth of vegetable insulating oil-based nanofluids. A nanoparticle polarization model considering surfactant polarization was proposed to calculate the trapping depth of the nanofluids at different nanoparticle sizes and surfactant thicknesses. The results show the calculated values of the model are in a fairly good agreement with the experimental values.

Assessing framing assumptions in quantitative health impact assessments: a housing intervention example.

PubMed

Mesa-Frias, Marco; Chalabi, Zaid; Foss, Anna M

2013-09-01

Health impact assessment (HIA) is often used to determine ex ante the health impact of an environmental policy or an environmental intervention. Underpinning any HIA is the framing assumption, which defines the causal pathways mapping environmental exposures to health outcomes. The sensitivity of the HIA to the framing assumptions is often ignored. A novel method based on fuzzy cognitive map (FCM) is developed to quantify the framing assumptions in the assessment stage of a HIA, and is then applied to a housing intervention (tightening insulation) as a case-study. Framing assumptions of the case-study were identified through a literature search of Ovid Medline (1948-2011). The FCM approach was used to identify the key variables that have the most influence in a HIA. Changes in air-tightness, ventilation, indoor air quality and mould/humidity have been identified as having the most influence on health. The FCM approach is widely applicable and can be used to inform the formulation of the framing assumptions in any quantitative HIA of environmental interventions. We argue that it is necessary to explore and quantify framing assumptions prior to conducting a detailed quantitative HIA during the assessment stage. Copyright © 2013 Elsevier Ltd. All rights reserved.

EPA SPF Insulation Research Update

EPA Science Inventory

This is a non-technical (no data) presentation that is intended to inform ACC/CPI about our intended approach to full-scale emissions testing that includes the application of spray foam in an environmental chamber. The presentation describes the approach to emissions characteriza...

Cryopumping in Cryogenic Insulations for a Reusable Launch Vehicle

NASA Technical Reports Server (NTRS)

Johnson, Theodore F.; Weiser, Erik S.; Grimsley, Brian W.; Jensen, Brian J.

2003-01-01

Testing at cryogenic temperatures was performed to verify the material characteristics and manufacturing processes of reusable propellant tank cryogenic insulations for a Reusable Launch Vehicle (RLV). The unique test apparatus and test methods developed for the investigation of cryopumping in cryogenic insulations are described. Panel level test specimens with various types of cryogenic insulations were subjected to a specific thermal profile where the temperature varied from -262 C to 21 C. Cryopumping occurred if the interior temperature of the specimen exhibited abnormal temperature fluctuations, such as a sudden decrease in temperature during the heating phase.

Waveguide embedded plasmon laser with multiplexing and electrical modulation

DOEpatents

Ma, Ren-min; Zhang, Xiang

2017-08-29

This disclosure provides systems, methods, and apparatus related to nanometer scale lasers. In one aspect, a device includes a substrate, a line of metal disposed on the substrate, an insulating material disposed on the line of metal, and a line of semiconductor material disposed on the substrate and the insulating material. The line of semiconductor material overlaying the line of metal, disposed on the insulating material, forms a plasmonic cavity.

Simulation of heat losses and ground temperatures for district-heating culverts. Comparison with field experiments for well-insulated, damaged, and extra-insulated culverts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hagentoft, C.E.

1986-01-01

Many old district-heating culverts are in bad condition due to the entry of water into the thermal insulation. The thermal conductivity, and thereby the heat loss from the culvert, is much larger for a wet than a dry thermal insulation. The high energy prices make it interesting and necessary to find the water-damaged parts of the district-heating culvert and improve the thermal insulation so that a reduction in the heat losses is obtained. The aim of the project is to develop a simple field method to determine the heat loss and the condition of the culvert. The method is basedmore » on the measurement of the temperature on the top of the culvert and a classification of the soil. The classification of the soil gives an estimation of its thermal conductivity. The heat loss and the reduction in heat loss due to an extra insulation is estimated from these data. Five different types of culverts were tested: two types of asbestos cement culverts, one concrete culvert, and two aerated concrete culverts. The comparison of the measured temperatures and the temperatures obtained from the simulations is reported in the study.« less

On the use of doped polyethylene as an insulating material for HVDC cables

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khalil, M.S.

1996-12-31

The merits of HVDC cables with polymeric insulation are well recognized. However, the development of such cables is still hampered due to the problems resulting from the complicated dependence of the electrical conductivity of the polymer on the temperature and the dc electric field and the effects of space charge accumulation in this material. Different methods have been suggested to solve these problems yet none of these methods seem to give a conclusive solution. The present report provides, firstly a critical review of the previous works reported in the literature concerning the development of HVDC cables with polymeric insulation. Differentmore » aspects of those works are examined and discussed. Secondly, an account is given on an investigation using low density polyethylene (LDPE) doped with an inorganic additive as a candidate insulating material for HVDC cables. Preliminary results from measurements of dc breakdown strength and insulation resistivity of both the undoped and the doped materials are presented. It is shown that the incorporation of an inorganic additive into LDPE has improved the performance of the doped material under polarity reversal dc conditions at room temperature. Moreover, the dependency of the insulation resistivity on temperature for the doped material appears to be beneficially modified.« less

Insulation effect on thermal stability of Coated Conductors wires in liquid nitrogen

NASA Astrophysics Data System (ADS)

Rubeli, Thomas; Dutoit, Bertrand; Martynova, Irina; Makarevich, Artem; Molodyk, Alexander; Samoilenkov, Sergey

2017-02-01

Superconducting wires are not perfectly homogeneous in term of critical current as well as stabilization. In resistive fault current limiter applications this could lead to hot spots if the fault current is only slightly above the nominal current of the device. Increasing stabilization by using thicker silver coating for example may prevent this problem but this method implies longer wire length to maintain the same impedance during a fault. Very efficient cooling in another way to prevent hot spots, this can be achieved in nucleate boiling regime. Optimal insulation can be used to prevent film boiling regime, staying in nucleate boiling regime in a much broader temperature range. In this work a novel technique is used to monitor in real time the temperature of the wire during the quench. Using this method several increasing insulation thicknesses are tested, measuring for each the heat exchange rate to the nitrogen bath. Exchange rate measurements are made in quasistatic regime and during the re-cooling of the wire. SuperOx wires provided with different insulation thicknesses exhibit an excellent stability, far above a bare wire. On the other side, for very thick insulations the stability gain is lost. Re-cooling speeds dependency on insulation thicknesses is measured too.

Superfluid-insulator transitions of two-species bosons in an optical lattice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isacsson, A.; Department of Physics, Yale University, P.O. Box 208120, New Haven, Connecticut 06520-8120; Cha, M.-C.

2005-11-01

We consider the two-species bosonic Hubbard model with variable interspecies interaction and hopping strength in the grand canonical ensemble with a common chemical potential. We analyze the superfluid-insulator (SI) transition for the relevant parameter regimes and compute the ground state phase diagram in the vicinity of odd filling Mott states. We find that the superfluid-insulator transition occurs with (a) simultaneous onset of superfluidity of both species or (b) coexistence of Mott insulating state of one species and superfluidity of the other or, in the case of unit filling (c) complete depopulation of one species. The superfluid-insulator transition can be firstmore » order in a large region of the phase diagram. We develop a variational mean-field method which takes into account the effect of second order quantum fluctuations on the superfluid-insulator transition and corroborate the mean-field phase diagram using a quantum Monte Carlo study.« less

Phase change thermal control materials, method and apparatus

NASA Technical Reports Server (NTRS)

Buckley, Theresa M. (Inventor)

2001-01-01

An apparatus and method for metabolic cooling and insulation of a user in a cold environment. In its preferred embodiment the apparatus is a highly flexible composite material having a flexible matrix containing a phase change thermal storage material. The apparatus can be made to heat or cool the body or to act as a thermal buffer to protect the wearer from changing environmental conditions. The apparatus may also include an external thermal insulation layer and/or an internal thermal control layer to regulate the rate of heat exchange between the composite and the skin of the wearer. Other embodiments of the apparatus also provide 1) a path for evaporation or direct absorption of perspiration from the skin of the wearer for improved comfort and thermal control, 2) heat conductive pathways within the material for thermal equalization, 3) surface treatments for improved absorption or rejection of heat by the material, and 4) means for quickly regenerating the thermal storage capacity for reuse of the material. Applications of the composite materials are also described which take advantage of the composite's thermal characteristics. The examples described include a diver's wet suit, ski boot liners, thermal socks, gloves and a face mask for cold weather activities, and a metabolic heating or cooling blanket useful for treating hypothermia or fever patients in a medical setting and therapeutic heating or cooling orthopedic joint supports.

Cork-resin ablative insulation for complex surfaces and method for applying the same

NASA Technical Reports Server (NTRS)

Walker, H. M.; Sharpe, M. H.; Simpson, W. G. (Inventor)

1980-01-01

A method of applying cork-resin ablative insulation material to complex curved surfaces is disclosed. The material is prepared by mixing finely divided cork with a B-stage curable thermosetting resin, forming the resulting mixture into a block, B-stage curing the resin-containing block, and slicing the block into sheets. The B-stage cured sheet is shaped to conform to the surface being insulated, and further curing is then performed. Curing of the resins only to B-stage before shaping enables application of sheet material to complex curved surfaces and avoids limitations and disadvantages presented in handling of fully cured sheet material.

Advanced Ablative Insulators and Methods of Making Them

NASA Technical Reports Server (NTRS)

Congdon, William M.

2005-01-01

Advanced ablative (more specifically, charring) materials that provide temporary protection against high temperatures, and advanced methods of designing and manufacturing insulators based on these materials, are undergoing development. These materials and methods were conceived in an effort to replace the traditional thermal-protection systems (TPSs) of re-entry spacecraft with robust, lightweight, better-performing TPSs that can be designed and manufactured more rapidly and at lower cost. These materials and methods could also be used to make improved TPSs for general aerospace, military, and industrial applications.

Polyimide foams provide thermal insulation and fire protection

NASA Technical Reports Server (NTRS)

Rosser, R. W.

1972-01-01

Chemical reactions to produce polyimide foams for application as thermal insulation and fire prevention materials are discussed. Thermal and physical properties of the polyimides are described. Methods for improving basic formulations to produce desired qualitites are included.

Identification and location of catenary insulator in complex background based on machine vision

NASA Astrophysics Data System (ADS)

Yao, Xiaotong; Pan, Yingli; Liu, Li; Cheng, Xiao

2018-04-01

It is an important premise to locate insulator precisely for fault detection. Current location algorithms for insulator under catenary checking images are not accurate, a target recognition and localization method based on binocular vision combined with SURF features is proposed. First of all, because of the location of the insulator in complex environment, using SURF features to achieve the coarse positioning of target recognition; then Using binocular vision principle to calculate the 3D coordinates of the object which has been coarsely located, realization of target object recognition and fine location; Finally, Finally, the key is to preserve the 3D coordinate of the object's center of mass, transfer to the inspection robot to control the detection position of the robot. Experimental results demonstrate that the proposed method has better recognition efficiency and accuracy, can successfully identify the target and has a define application value.

Method and technique for installing light-weight, fragile, high-temperature fiber insulation

NASA Technical Reports Server (NTRS)

Patel, B. C. (Inventor)

1983-01-01

A method of installing fragile, light weight, high temperature fiber insulation, particularly where the insulation is to be used as a seal strip providing a high order of thermal barrier insulation is discussed. The process is based on provision of a strip of the mineral batting cut oversize by a predetermined amount, saturated in a fugitive polymer solution, compressed in a mold, dried and cured to form a rigidized batting material which is machined to required shape. The machine dimensions would normally be at least nominally less than the dimensions of the cavity to be sealed. After insertion in the cavity, which may be a wire-mesh seal enclosure, the apparatus is subjected to baking at a temperature sufficiently high to cause the resin to burn off cleanly, leaving the batting substantially in its original condition and expanded into the cavity or seal enclosure.

A method and technique for installing light-weight fragile, high-temperature fiber insulation

NASA Technical Reports Server (NTRS)

Ballantine, T. J. (Inventor)

1982-01-01

A method of installing fragile, light-weight, high-temperature fiber insulation, particularly where the insulation is to be used as a seal strip providing a high order of thermal barrier insulation is described. The process is based on provision of a strip of the mineral batting cut oversize by a predetermined amount, saturated in a fugitive polymer solution, compressed in a mold, dried and cured to form a rigidized batting material which may be machined to required shape. The machined dimensions would normally be at least nominally less than the dimensions of the cavity to be sealed. After insertion in the cavity, which may be a wire-mesh seal enclosure, the apparatus is subjected to baking at a temperature sufficiently high to cause the resin to burn off cleanly, leaving the batting substantially in its original condition and expanded into the cavity or seal enclosure.

Study of multilayer thermal insulation by inverse problems method

NASA Astrophysics Data System (ADS)

Alifanov, O. M.; Nenarokomov, A. V.; Gonzalez, V. M.

2009-11-01

The purpose of this paper is to introduce a new method in the research of radiative and thermal properties of materials with further applications in the design of thermal control systems (TCS) of spacecrafts. In this paper the radiative and thermal properties (emissivity and thermal conductance) of a multilayered thermal-insulating blanket (MLI), which is a screen-vacuum thermal insulation as a part of the TCS for perspective spacecrafts, are estimated. Properties of the materials under study are determined in the result of temperature and heat flux measurement data processing based on the solution of the inverse heat transfer problem (IHTP) technique. Given are physical and mathematical models of heat transfer processes in a specimen of the multilayered thermal-insulating blanket located in the experimental facility. A mathematical formulation of the inverse heat conduction problem is presented as well. The practical approves were made for specimen of the real MLI.

Method and apparatus for an insulating glazing unit and compliant seal for an insulating glazing unit

DOEpatents

Francis, IV, William H.; Freebury, Gregg E.; Beidleman, Neal J.; Hulse, Michael

2016-05-03

A Vacuum Insulating Glazing Unit (VIGU) comprises two or more glass lites (panes) spaced apart from one another and hermetically bonded to an edge seal assembly therebetween. The resulting cavity between the lites is evacuated to create at least one insulating vacuum cavity within which are disposed a plurality of stand-off members to maintain separation between the lites. The edge seal assembly is preferably compliant in the longitudinal (i.e., edgewise) direction to allow longitudinal relative motion between the two lites (e.g., from thermal expansion). The longitudinal compliance may be obtained by imprinting a three-dimensional pattern into the edge seal material. The edge seal assembly is preferably bonded to the lites with a first bond portion that is hermetic and a second bond portion that is load-resistant. Methods for producing VIGUs and/or compliant edge seal assemblies and VIGU and edge seal apparatus are disclosed.

Insulating Materials Comprising Polysilazane, Methods of Forming Such Insulating Materials, and Precursor Formulations Comprising Polysilazane

NASA Technical Reports Server (NTRS)

Larson, Robert S. (Inventor); Fuller, Michael E. (Inventor)

2013-01-01

Methods of forming an insulating material comprising combining a polysilazane, a cross-linking compound, and a gas-generating compound to form a reaction mixture, and curing the reaction mixture to form a modified polysilazane. The gas-generating compound may be water, an alcohol, an amine, or combinations thereof. The cross-linking compound may be an isocyanate, an epoxy resin, or combinations thereof. The insulating material may include a matrix comprising one of a reaction product of a polysilazane and an isocyanate and a reaction product of a polysilazane and an epoxy resin. The matrix also comprises a plurality of interconnected pores produced from one of reaction of the polysilazane and the isocyanate and from reaction of the polysilazane and the epoxy resin. A precursor formulation that comprises a polysilazane, a cross-linking compound, and a gas-generating compound is also disclosed.

Field joint environmental protection system vibration/pressurization qualification

NASA Technical Reports Server (NTRS)

Cook, M.

1989-01-01

The procedures used and results obtained from vibration testing the redesigned solid rocket motor (RSRM) field joint environmental protection system (FJEPS), hereafter referred to as the joint protection system (JPS) are documented. The major purposes were to certify that the flight-designed JPS will withstand the dynamic environmental conditions of the redesigned solid rocket booster, and to certify that the cartridge check valve (vent valve) will relieve pressure build-up under the JPS during the initial 120 sec of flight. Also, an evaluation of the extruded cork insulation bonding was performed after the vibration testing.

Repairing Foam Insulation

NASA Technical Reports Server (NTRS)

Corbin, J.; Buras, D.

1986-01-01

Large holes in polyurethane foam insulation repaired reliably by simple method. Little skill needed to apply method, used for overhead repairs as well as for those in other orientations. Plug positioned in hole to be filled and held in place with mounting fixture. Fresh liquid foam injected through plug to bond it in place. As foam cures and expands, it displaces plug outward. Protrusion later removed.

Potential of Progressive Construction Systems in Slovakia

NASA Astrophysics Data System (ADS)

Kozlovska, Maria; Spisakova, Marcela; Mackova, Daniela

2017-10-01

Construction industry is a sector with rapid development. Progressive technologies of construction and new construction materials also called modern methods of construction (MMC) are developed constantly. MMC represent the adoption of construction industrialisation and the use of prefabrication of components in building construction. One of these modern methods is also system Varianthaus, which is based on, insulated concrete forms principle and provides complete production plant for wall, ceiling and roof elements for a high thermal insulation house construction. Another progressive construction system is EcoB, which represents an insulated precast concrete panel based on combination of two layers, insulation and concrete, produced in a factory as a whole. Both modern methods of construction are not yet known and wide-spread in the Slovak construction market. The aim of this paper is focused on demonstration of MMC using potential in Slovakia. MMC potential is proved based on comparison of the selected parameters of construction process - construction costs and construction time. The subject of this study is family house modelled in three material variants - masonry construction (as a representative of traditional methods of construction), Varianthaus and EcoB (as the representatives of modern methods of construction). The results of this study provide the useful information in decision-making process for potential investors of construction.

The Development and Application of Simulative Insulation Resistance Tester

NASA Astrophysics Data System (ADS)

Jia, Yan; Chai, Ziqi; Wang, Bo; Ma, Hao

2018-02-01

The insulation state determines the performance and insulation life of electrical equipment, so it has to be judged in a timely and accurate manner. Insulation resistance test, as the simplest and most basic test of high voltage electric tests, can measure the insulation resistance and absorption ratio which are effective criterion of part or whole damp or dirty, breakdown, severe overheating aging and other insulation defects. It means that the electrical test personnel need to be familiar with the principle of insulation resistance test, and able to operate the insulation resistance tester correctly. At present, like the insulation resistance test, most of electrical tests are trained by physical devices with the real high voltage. Although this allows the students to truly experience the test process and notes on security, it also has certain limitations in terms of safety and test efficiency, especially for a large number of new staves needing induction training every year. This paper presents a new kind of electrical test training system based on the simulative device of dielectric loss measurement and simulative electrical testing devices. It can not only overcome the defects of current training methods, but also provide other advantages in economical efficiency and scalability. That makes it possible for the system to be allied in widespread.

Development of Structure and Characteristics Calculation Method for Γ- shape Rope Vubration Insulator

NASA Astrophysics Data System (ADS)

Ponomarev, Yury K.

2018-01-01

The paper gives an overview of the design of rope vibration insulators with elastic elements of the center line in the form of two rectilinear and one curved section. In the Russian-language scientific literature this type of rope vibration insulators received a stable name "Γ-shaped vibration insulators” by analogy with the shape of the letter “gamma-Γ" of the Greek alphabet and a similar letter of the Cyrillic alphabet. Despite the wide using of vibration insulators designed on this shape, its mathematical calculation model has not yet been developed. In this connection, in this article, for the first time on the basis of the “Method of Forces” and the “Mohr Method”, an analytical technique has been developed for calculating the characteristics of a vibration insulator in the directions of three mutually perpendicular axes. In addition, the article proposes a new structure of a vibration insulator consisting of several tiers of elements of this type, based on a new patented technology for manufacturing quasi-continuous woven rings, proposed by the author of this article in co-authorship with several employees of the Samara National Research University. Simple formulas are obtained for calculating the load characteristics in three mutually perpendicular directions. This makes it possible to calculate the corresponding stiffness and natural frequencies of mechanical vibration protection systems. It is established that the stiffness of the vibration insulator in the direction of the Z axis is greater than the stiffness in the X and Y axis directions, however, if a vibration insulator with equal, or close to equal characteristics, along three axes has to be designed according to the technical specification, this can be done by selecting the parameters included in the equations given in article for load characteristics.

Design and Evaluation of a Ventilated Garment for Use in Temperatures up to 200°C

PubMed Central

Crockford, G. W.; Hellon, R. F.

1964-01-01

The protection of personnel against high air and radiant temperatures is a problem that has been confronting industry for many years now, and for many industrial situations it still has not been solved. The experiments reported here were intended to determine the most suitable form of insulation for a hot entry suit for use primarily in furnace wrecking where mean radiant temperatures of 200°C. are met and where heat-reflecting garments are unsuitable due to the rapid deterioration of the reflecting surface. From a preliminary consideration of the problem it was concluded that a ventilated garment was required and that conventional ventilated garments in which air is induced to flow parallel to the body surfaces (axial ventilation) are basically unsound in design as the air is not utilized for the transfer of heat in the most efficient manner. A new form of ventilation was therefore developed in which air flows out through a permeable suit (radial ventilation). This form of ventilation produces what is called dynamic insulation, and this method of insulation, when compared with two alternative methods on a physical model, was found to be very effective. The model experiments were confirmed by comparative trials of three ventilated suits each using one of three different forms of insulation thought to be suitable for use in heat-protective clothing. Physiological measurements made on the subjects and physical measurement made on the suits confirmed that dynamic insulation is the most suitable insulation for a hot entry suit for furnace wrecking. With the air flows used in these experiments, dynamic insulation had a thermal conductance one-fifth that of conventional static insulation, and sweat losses and oral temperature rises were reduced by one-third and one-half respectively. PMID:14180476

Spray-On Foam Insulations for Launch Vehicle Cryogenic Tanks

NASA Technical Reports Server (NTRS)

Fesmire, J. E.; Cofman, B. E.; Menghelli, B. J.; Heckle, K. W.

2011-01-01

Spray-on foam insulation (SOFI) has been developed for use on the cryogenic tanks of space launch vehicles beginning in the 1960s with the Apollo program. The use of SOFI was further developed for the Space Shuttle program. The External Tank (ET) of the Space Shuttle, consisting of a forward liquid oxygen tank in line with an aft liquid hydrogen tank, requires thermal insulation over its outer surface to prevent ice formation and avoid in-flight damage to the ceramic tile thermal protection system on the adjacent Orbiter. The insulation also provides system control and stability with throughout the lengthy process of cooldown, loading, and replenishing the tank. There are two main types of SOFI used on the ET: acreage (with the rind) and closeout (machined surface). The thermal performance of the seemingly simple SOFI system is a complex of many variables starting with the large temperature difference of from 200 to 260 K through the typical 25-mm thickness. Environmental factors include air temperature and humidity, wind speed, solar exposure, and aging or weathering history. Additional factors include manufacturing details, launch processing operations, and number of cryogenic thermal cycles. The study of the cryogenic thermal performance of SOFI under large temperature differentials is the subject of this article. The amount of moisture taken into the foam during the cold soak phase, termed Cryogenic Moisture Uptake, must also be considered. The heat leakage rates through these foams were measured under representative conditions using laboratory standard liquid nitrogen boiloff apparatus. Test articles included baseline, aged, and weathered specimens. Testing was performed over the entire pressure range from high vacuum to ambient pressure. Values for apparent thermal conductivity and heat flux were calculated and compared with prior data. As the prior data of record was obtained for small temperature differentials on non-weathered foams, analysis of the different methods is provided. Recent advancements and applications of SOFI systems on future launch vehicles and spacecraft are also addressed.

Heat Transfer in High Temperature Multilayer Insulation

NASA Technical Reports Server (NTRS)

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

2007-01-01

High temperature multilayer insulations have been investigated as an effective component of thermal-protection systems for atmospheric re-entry of reusable launch vehicles. Heat transfer in multilayer insulations consisting of thin, gold-coated, ceramic reflective foils and Saffil(TradeMark) fibrous insulation spacers was studied both numerically and experimentally. A finite volume numerical thermal model using combined conduction (gaseous and solid) and radiation in porous media was developed. A two-flux model with anisotropic scattering was used for radiation heat transfer in the fibrous insulation spacers between the reflective foils. The thermal model was validated by comparison with effective thermal conductivity measurements in an apparatus based on ASTM standard C201. Measurements were performed at environmental pressures in the range from 1x10(exp -4) to 760 torr over the temperature range from 300 to 1300 K. Four multilayer samples with nominal densities of 48 kg/cu m were tested. The first sample was 13.3 mm thick and had four evenly spaced reflective foils. The other three samples were 26.6 mm thick and utilized either one, two, or four reflective foils, located near the hot boundary with nominal foil spacing of 1.7 mm. The validated thermal model was then used to study relevant design parameters, such as reflective foil spacing and location in the stack-up and coating of one or both sides of foils.

Initial and Long-Term Movement of Cladding Installed Over Exterior Rigid Insulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, P.

Changes in the International Energy Conservation Code (IECC) from 2009 to 2012 have resulted in the use of exterior rigid insulation becoming part of the prescriptive code requirements. With more jurisdictions adopting the 2012 IECC builders are going to finding themselves required to incorporate exterior insulation in the construction of their exterior wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location. However, there has beenmore » a significant resistance to its widespread implementation due to a lack of research and understanding of the mechanisms involved and potential creep effects of the assembly under the sustained dead load of a cladding. This research was an extension on previous research conducted by BSC in 2011, and 2012. Each year the understanding of the system discrete load component interactions, as well as impacts of environmental loading has increased. The focus of the research was to examine more closely the impacts of screw fastener bending on the total system capacity, effects of thermal expansion and contraction of materials on the compressive forces in the assembly, as well as to analyze a full years worth of cladding movement data from assemblies constructed in an exposed outdoor environment.« less

Uncle Sam Flunks Asbestos Control in Schools.

ERIC Educational Resources Information Center

Gough, Michael

1988-01-01

Discusses the problem of using asbestos to insulate heating and air-conditioning systems in schools and mixing asbestos into ceiling plaster for fireproofing and noise control. Suggests that the Environmental Protection Agency's plan for asbestos removal may be causing problems where none exist. (TW)

PCB DECHLORINATION BY PD/MG BIMETALLIC CORROSION NANO-CELLS

EPA Science Inventory

Polychlorinated biphenyls (PCBs), manufacture-1970's for use as electrical insulators, were banned in 1979 due to their toxicity and persistence in the environment. They are recalcitrant environmental pollutants, found in numerous rivers, coastal waters and in 500 of the nation's...

Dynamical mean field theory equations on nearly real frequency axis

NASA Astrophysics Data System (ADS)

Fathi, M. B.; Jafari, S. A.

2010-03-01

The iterated perturbation theory (IPT) equations of the dynamical mean field theory (DMFT) for the half-filled Hubbard model are solved on nearly real frequencies at various values of the Hubbard parameters, U, to investigate the nature of metal-insulator transition (MIT) at finite temperatures. This method avoids the instabilities associated with the infamous Padé analytic continuation and reveals fine structures across the MIT at finite temperatures, which cannot be captured by conventional methods for solving DMFT-IPT equations on Matsubara frequencies. Our method suggests that at finite temperatures, there is a crossover from a bad metal to a bad insulator in which the height of the quasi-particle (Kondo) peak decreases to a non-zero small bump, which gradually suppresses as one moves deeper into the bad insulating regime.

Depolarization current relaxation process of insulating dielectrics after corona poling under different charging conditions

NASA Astrophysics Data System (ADS)

Zhang, J. W.; Zhou, T. C.; Wang, J. X.; Yang, X. F.; Zhu, F.; Tian, L. M.; Liu, R. T.

2017-10-01

As an insulating dielectric, polyimide is favorable for the application of optoelectronics, electrical insulation system in electric power industry, insulating, and packaging materials in space aircraft, due to its excellent thermal, mechanical and electrical insulating stability. The charge storage profile of such insulating dielectric is utmost important to its application, when it is exposed to electron irradiation, high voltage corona discharge or other treatments. These treatments could induce changes in physical and chemical properties of treated samples. To investigate the charge storage mechanism of the insulating dielectrics after high-voltage corona discharge, the relaxation processes responsible for corona charged polyimide films under different poling conditions were analyzed by the Thermally Stimulated Discharge Currents method (TSDC). In the results of thermal relaxation process, the appearance of various peaks in TSDC spectra provided a deep insight into the molecular status in the dielectric material and reflected stored space charge relaxation process in the insulating polymers after corona discharge treatments. Furthermore, the different space charge distribution status under various poling temperature and different discharge voltage level were also investigated, which could partly reflect the influence of the ambiance condition on the functional dielectrics after corona poling.

Breakdown Characteristics and Streaming Electrification Characteristics of Flame Retardant Silicone Oil

NASA Astrophysics Data System (ADS)

Arazoe, Satoshi; Yasuda, Koji; Okabe, Shigemitsu; Ueta, Genyo; Yanabu, Satoru

We have investigated the performance of the silicone oil as alternative oil to the mineral oil that is used as an insulation medium of the oil immersed transformer. There are various methods of evaluating the performance, we especially investigated the breakdown characteristics and the streaming electrification characteristics. In the breakdown characteristics, the insulation performance under the influence of changing the temperature, and the electrode shape was investigated. Moreover, the insulation performance in the composite insulation system that was composed of the insulation oil and the oil immersed insulator was investigated. From these results, we found that in the oil gap model, the breakdown voltage of silicone oil was lower than that of mineral oil by 15%. In contrast, in the composite insulation system, breakdown voltage of combination with silicone oil is higher than that of combination with mineral oil. In the streaming electrification characteristics, the difference of the amount of electrification under the influence of changing the kinds of solid insulators and the temperature was investigated. As a result, we found that silicone oil has the maximum of the amount of electrification at a high temperature compared with mineral oil.

Tracking of Nuclear Cable Insulation Polymer Structural Changes using the Gel Fraction and Uptake Factor Method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Correa, Miguel; Huang, Qian; Fifield, Leonard S.

Cross-linked polyethylene (XLPE) cable insulation samples were exposed to heat and gamma radiation at a series of temperatures, dose rates, and exposure times to evaluate the effects of these variables on material degradation. The samples were tested using the solvent incubation method to collect gel fraction and uptake factor data in order to assess the crosslinking and chain scission occurring in polymer samples with aging. Consistent with previous reports, gel fraction values were observed to increase and uptake factor values to decrease with radiation and thermal exposure. The trends seen were also more prominent as exposure time increased, suggesting thismore » to be a viable method of tracking structural changes in the XLPE-insulated cable material over extended periods. For the conditions explored, the cable insulation material evaluated did not indicate signs of anomalous aging such as inverse temperature effect in which radiation-induced aging is more severe at lower temperature. Ongoing aging under identical radiation conditions and at lower temperature will further inform conclusions regarding the importance of inverse temperature effects for this material under these conditions.« less

Environmental Assessment (EA) for the Comprehensive Range Plan (CRP), Melrose Air Force Range (AFR), New Mexico

DTIC Science & Technology

2011-07-01

11,674 sq ft C-130 maintenance hangar with reinforced concrete footings, a foundation and footing slab, a structural steel frame, insulated metal...regional farming output significantly; however, it could potentially have a detrimental effect to the lessee. Environmental Justice – There are no...Facility – Construct a pre-engineered one story steel framed structure including the necessary concrete foundations to support the building.  SOF

Using fiberglass volumes for VPI of superconductive magnetic systems’ insulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andreev, I. S.; Bezrukov, A. A.; Pischugin, A. B.

2014-01-29

The paper describes the method of manufacturing fiberglass molds for vacuum pressure impregnation (VPI) of high-voltage insulation of superconductive magnetic systems (SMS) with epoxidian hot-setting compounds. The basic advantages of using such vacuum volumes are improved quality of insulation impregnation in complex-shaped areas, and considerable cost-saving of preparing VPI of large-sized components due to dispensing with the stage of fabricating a metal impregnating volume. Such fiberglass vacuum molds were used for VPI of high-voltage insulation samples of an ITER reactor’s PF1 poloidal coil. Electric insulation of these samples has successfully undergone a wide range of high-voltage and mechanical tests atmore » room and cryogenic temperatures. Some results of the tests are also given in this paper.« less

Summary of Activities for Nondestructive Evaluation of Insulation in Cryogenic Tanks

NASA Technical Reports Server (NTRS)

Arens, Ellen

2012-01-01

This project was undertaken to investigate methods to non-intrusively determine the existence and density of perlite insulation in the annular region of the cryogenic storage vessels, specifically considering the Launch Complex 39 hydrogen tanks at Kennedy Space Center. Lack of insulation in the tanks (as existed in the pad B hydrogen tank at Kennedy Space Center) results in an excessive loss of commodity and can pose operational and safety risks if precautions are not taken to relieve the excessive gas build-up. Insulation with a density that is higher than normal (due to settling or compaction) may also pose an operational and safety risk if the insulation prevents the system from moving and responding to expansions and contractions as fluid is removed and added to the tank.

Treeing phenomenon of thermoplastic polyethylene blends for recyclable cable insulation materials

NASA Astrophysics Data System (ADS)

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.

Aging of XLPE cable insulation under combined electrical and mechanical stresses

DOE Office of Scientific and Technical Information (OSTI.GOV)

David, E.; Parpal, J.L.; Crine, J.P.

1996-12-31

Extruded crosslinked polyethylene (XLPE) insulation is widely used in high-voltage cables since it presents such attractive features as excellent dielectric properties and good thermomechanical behavior. However, its performance is affected by long-term degradation when it is subjected to the various thermal, mechanical and environmental stresses occurring in service in combination with electrical stress. The synergetic effect of superposed electrical and other stresses remains to be fully clarified. In particular, a fairly high level of mechanical stresses can be present in the insulation volume, originating from residual internal stresses created during the cooling process in the fabrication, external forces when cablesmore » are bent sharply, or thermomechanical stresses caused by differential thermal expansion between the conductor and the insulating material. In order to investigate the influence of the superposition of mechanical and electrical stresses, various measurements were conducted on XLPE and LDPE specimens in tip-plane and plane-plane geometries. Experimental data of time-to-breakdown, breakdown field and tree length are presented as a function of the magnitude of the stresses. In all cases, superposition of the mechanical stress was found to reduce the dielectric strength of the material.« less

In-field implementation of impedance-based structural health monitoring for insulated rail joints

NASA Astrophysics Data System (ADS)

Albakri, Mohammad I.; Malladi, V. V. N. Sriram; Woolard, Americo G.; Tarazaga, Pablo A.

2017-04-01

Track defects are a major safety concern for the railroad industry. Among different track components, insulated rail joints, which are widely used for signaling purposes, are considered a weak link in the railroad track. Several joint-related defects have been identified by the railroad community, including rail wear, torque loss, and joint bar breakage. Current track inspection techniques rely on manual and visual inspection or on specially equipped testing carts, which are costly, timeconsuming, traffic disturbing, and prone to human error. To overcome the aforementioned limitations, the feasibility of utilizing impedance-based structural health monitoring for insulated rail joints is investigated in this work. For this purpose, an insulated joint, provided by Koppers Inc., is instrumented with piezoelectric transducers and assembled with 136 AREA rail plugs. The instrumented joint is then installed and tested at the Facility for Accelerated Service Testing, Transportation Technology Center Inc. The effects of environmental and operating conditions on the measured impedance signatures are investigated through a set of experiments conducted at different temperatures and loading conditions. The capabilities of impedance-based SHM to detect several joint-related damage types are also studied by introducing reversible mechanical defects to different joint components.

Characterization of Solid Polymers, Ceramic Gap Filler, and Closed-Cell Polymer Foam Using Low-Load Test Methods

NASA Technical Reports Server (NTRS)

Herring, Helen M.

2008-01-01

Various solid polymers, polymer-based composites, and closed-cell polymer foam are being characterized to determine their mechanical properties, using low-load test methods. The residual mechanical properties of these materials after environmental exposure or extreme usage conditions determines their value in aerospace structural applications. In this experimental study, four separate polymers were evaluated to measure their individual mechanical responses after thermal aging and moisture exposure by dynamic mechanical analysis. A ceramic gap filler, used in the gaps between the tiles on the Space Shuttle, was also tested, using dynamic mechanical analysis to determine material property limits during flight. Closed-cell polymer foam, used for the Space Shuttle External Tank insulation, was tested under low load levels to evaluate how the foam's mechanical properties are affected by various loading and unloading scenarios.

The Investigation Of Carbon Contamination And Sputtering Effects Of Xenon Ion Thrusters

NASA Technical Reports Server (NTRS)

Prak, Moline K.

2004-01-01

The Electro-Physics Branch of the NASA Glenn Research Center investigates the effect of atomic oxygen, environmental durability of high performance power materials and surfaces, and low earth orbit. One of its current projects involves the analysis of ion thrusters. Ion thrusters are devices that initiate a beam of ions to a target area. The type of ion thruster that I have been working with this Summer of 2004 emits positively charged Xenon (Xe(+)) atoms through two grids, the screen grid and the accelerator grid, after it enters an ionization chamber. Insulators are used to mechanically hold and separate these two grids. A propellant isolator, an instrument that closely resembles insulators, is placed in front of the ionization chamber. Both the insulator and isolator are made with a ceramic compound and filled with insulating beads. The main difference between the two devices is that the propellant isolator allows gas to flow through, in this case, the gas is Xe(+) and the insulators do not. In order to avoid carbon deposits and other contaminating chemicals to settle on the insulators and propellant isolator, a metal shadow shield is placed around them. These shadow shields function as a protectant and can be shaped in numerous configurations. Part of my job responsibility this summer is to investigate the effectiveness of different shadow shields that are utilized on three different ion engines: the NSTAR (NASA Solar Electric Propulsion Technology Application Readiness), JIMO (Jupiter Icy Moons Orbiter), and NEXIS (Nuclear Electric Xenon Ion System). Using calculus and other mathematical tactics, I was asked to find the total flux of carbon contamination that was able to pass the protectant shadow shield. I familiarized myself with the software program, MathCad2004, to help perform some mathematical computations such as complex integration. Another method of studying the probability of contamination is by experimental simulation. After attaining the precise parameters of the actual shadow shields, I created replicas of three types of shadow shielding to be used to undergo testing. It will be placed in a machine that produces carbon atoms at a high temperature of 200 C. or beam is aimed at a targeted material. As a result of this collision, atoms and other particles are ejected out of the target surface. Another part of my internship consisted of research on sputter ejection, or the angle distribution of sputtered material. This research entailed finding the past results of sputter ejection investigation as well as creating another type of mock simulation. Other minor projects include calculating the path of Xe(+) gas through the insulating beads of the isolators and assisting my mentor in collecting data for his paper for the Joint Propulsion Conference & Exhibit to be held July 11-14,2004 in Fort Lauderdale, Florida.

Polymer/glass nanocomposite fiber as an insulating material

NASA Astrophysics Data System (ADS)

Taygun, M. Erol; Akkaya, I.; Gönen, S. Ö.; Küçükbayrak, S.

2017-02-01

Production of the insulation materials with using nanofibers is the unique idea. With this idea, insulating facilities are enhanced with compressing air between the layers of nanofibers. Basically, glass wool is used as an insulation material. On the other hand, nanofiber glasses can be preferred for insulation purposes to be able to obtain insulation materials better then glass wool. From this point of view in this study, glass nanofibers were formed with sol-gel method by utilizing electrospinning technique. In the experimental part, first of all, sol-gel and polyvinylpyrolidone (PVP)/ethanol solutions were prepared. Then the relation of rheological properties with electrospinnability of PVP/sol-gel solutions was investigated by using a rheometer. Results showed that viscosity increased with the concentration of PVP. Meanwhile, the morphology of electrospun PVP/glass nanofibers was investigated by scanning electron microscope. It was also observed that the homogeneous nanofiber structure was obtained when the viscosity of the solution was 0.006 Pa.s. According to SEM results, it was concluded that nanocomposite fiber having a nanostructured morphology may be a good candidate for thermal insulation applications in the industry.

Application of Ultrasonic Guided Waves for Evaluating Aging Wire Insulation

NASA Technical Reports Server (NTRS)

Anastasi, Robert F.; Madaras, Eric I.

2005-01-01

Aging wiring has become a critical issue to the aerospace and aircraft industries due to Shuttle and aircraft incidents. The problem is that over time the insulation on wire becomes brittle and cracks. This exposes the underlying conductive wire to the potential for short circuits and fire. Popular methods of monitoring aging wire problems focuses on applying electrical sensing techniques that are sensitive to the conductor's condition, but not very sensitive to the wire insulation's condition. Measurement of wire insulation stiffness and ultrasonic properties by ultrasonic guided waves is being examined. Experimental measurements showed that the lowest order extensional mode could be sensitive to stiffness changes in the wire insulation. To test this theory conventional wire samples were heat damaged in an oven, in a range of heating conditions. The samples were 12, 16, and 20 gauge and the heat damage introduced material changes in the wire insulation that made the originally flexible insulation brittle and darker in color. Results showed that extensional mode phase velocity increased for the samples that were exposed to heat for longer duration.

Fabrication of Cellulose Nanofiber/AlOOH Aerogel for Flame Retardant and Thermal Insulation

PubMed Central

Fan, Bitao; Chen, Shujun; Yao, Qiufang; Sun, Qingfeng; Jin, Chunde

2017-01-01

Cellulose nanofiber/AlOOH aerogel for flame retardant and thermal insulation was successfully prepared through a hydrothermal method. Their flame retardant and thermal insulation properties were investigated. The morphology image of the cellulose nanofiber/AlOOH exhibited spherical AlOOH with an average diameter of 0.5 μm that was wrapped by cellulose nanofiber or adhered to them. Cellulose nanofiber/AlOOH composite aerogels exhibited excellent flame retardant and thermal insulation properties through the flammability test, which indicated that the as-prepared composite aerogels would have a promising future in the application of some important areas such as protection of lightweight construction materials. PMID:28772670

A simultaneous characterization and uncertainty analysis of thermal conductivity and diffusivity of bio-insulate material "Palm date Wood" obtained from a periodic method

NASA Astrophysics Data System (ADS)

Tlijani, M.; Ben Younes, R.; Durastanti, J. F.; Boudenne, A.

2010-11-01

A periodic method is used to determine simultaneously both thermal conductivity and diffusivity of various insulate materials at room temperature. The sample is placed between two metallic plates and temperature modulation is applied on the front side of one of the metallic plates. The temperature at the front and rear sides of both plates is measured and the experimental transfer function is calculated. The theoretical thermal heat transfer function is calculated by the quadripole method. Thermal conductivity and diffusivity are simultaneously identified from both real and imaginary parts of the experimental transfer function. The thermophysical parameters of several wood scale samples obtained from palm wood trees and common trees with unknown thermal properties (E) with different thicknesses were studied. The value identified for the thermal conductivity 0.03 Wm-1 K-1 compared with different insulate solid material such as glass, glass-wool and PVC is much better and close to the air conductivity, It allowed us to consider the wood scale extracted from palm wood trees, bio and renewable material as good heat insulator aiming in the future as a use for lightness applications, insulating or as a reinforcement in a given matrix. These potentialities still unknown are stengthened by the enormous quantity of such kind of wood gathered annually from palm trees and considered as wastes.

Prescriptions for Sick Schools.

ERIC Educational Resources Information Center

Ornstein, Allan C.

1993-01-01

Increasing insulation in schools as an energy-saving measure has given rise to the Sick Building Syndrome (SBS), which afflicts roughly one-third of the nation's schools. This article examines asbestos, radon, electromagnetic radiation, and chemical pollutants and describes steps to make schools environmentally safe for students. School officials…

Methods for Determining the Optimum Design of Structures Protected from Aerodynamic Heating and Application to Typical Boost-Glide or Reentry Flight Paths

NASA Technical Reports Server (NTRS)

Harris, Robert S., Jr.; Davidson, John R.

1962-01-01

General equations are developed for the design of efficient structures protected from thermal environments typical of those encountered in boost-glide or atmospheric-reentry conditions. The method is applied to insulated heat-sink stressed-skin structures and to internally cooled insulated structures. Plates loaded in compression are treated in detail. Under limited conditions of plate buckling, high loading, and short flight periods, and for aluminum structures only, the weights of both configurations are nearly equal. Load parameters are found and are similar to those derived in previous investigations for the restricted case of a constant equilibrium temperature at the outside surface of the insulation.

Smart window coating based on F-TiO2-KxWO3 nanocomposites with heat shielding, ultraviolet isolating, hydrophilic and photocatalytic performance

PubMed Central

Liu, Tongyao; Liu, Bin; Wang, Jing; Yang, Linfen; Ma, Xinlong; Li, Hao; Zhang, Yihong; Yin, Shu; Sato, Tsugio; Sekino, Tohru; Wang, Yuhua

2016-01-01

A series of smart window coated multifunctional NIR shielding-photocatalytic films were fabricated successfully through KxWO3 and F-TiO2 in a low-cost and environmentally friendly process. Based on the synergistic effect of KxWO3 and F-TiO2, the optimal proportion of KxWO3 to F-TiO2 was investigated and the FT/2KWO nanocomposite film exhibited strong near-infrared, ultraviolet light shielding ability, good visible light transmittance, high photocatalytic activity and excellent hydrophilic capacity. This film exhibited better thermal insulation capacity than ITO and higher photocatalytic activity than P25. Meanwhile, the excellent stability of this film was examined by the cycle photocatalytic degradation and thermal insulation experiments. Overall, this work is expected to provide a possibility in integrating KxWO3 with F-TiO2, so as to obtain a multifunctional NIR shielding-photocatalytic nanocomposite film in helping solve the energy crisis and deteriorating environmental issues. PMID:27265778

Encapsulated silicene: A robust large-gap topological insulator

DOE PAGES

Kou, Liangzhi; Ma, Yandong; Yan, Binghai; ...

2015-08-20

The quantum spin Hall (QSH) effect predicted in silicene has raised exciting prospects of new device applications compatible with current microelectronic technology. Efforts to explore this novel phenomenon, however, have been impeded by fundamental challenges imposed by silicene’s small topologically nontrivial band gap and fragile electronic properties susceptible to environmental degradation effects. Here we propose a strategy to circumvent these challenges by encapsulating silicene between transition-metal dichalcogenides (TMDCs) layers. First-principles calculations show that such encapsulated silicene exhibit a two-orders-of-magnitude enhancement in its nontrivial band gap, which is driven by the strong spin–orbit coupling effect in TMDCs via the proximity effect.more » Moreover, the cladding TMDCs layers also shield silicene from environmental gases that are detrimental to the QSH state in free-standing silicene. In conclusion, the encapsulated silicene represents a novel two-dimensional topological insulator with a robust nontrivial band gap suitable for room-temperature applications, which has significant implications for innovative QSH device design and fabrication.« less

System and method for suppressing sublimation using opacified aerogel

NASA Technical Reports Server (NTRS)

Sakamoto, Jeff S. (Inventor); Snyder, G. Jeffrey (Inventor); Calliat, Thierry (Inventor); Fleurial, Jean-Pierre (Inventor); Jones, Steven M. (Inventor); Palk, Jong-Ah (Inventor)

2008-01-01

The present invention relates to a castable, aerogel-based, ultra-low thermal conductivity opacified insulation to suppress sublimation. More specifically, the present invention relates to an aerogel opacified with various opacifying or reflecting constituents to suppress sublimation and provide thermal insulation in thermoelectric modules. The opacifying constituent can be graded within the aerogel for increased sublimation suppression, and the density of the aerogel can similarly be graded to achieve optimal thermal insulation and sublimation suppression.

The full-scale process and design changes for elimination of insulation edge separations and voids in tang flap area

NASA Technical Reports Server (NTRS)

Danforth, Richard A.

1991-01-01

Qualification of the full-scale process and design changes for elimination of redesigned solid rocket motor tang nitrile butadiene rubber insulation edge separations and voids was performed from 24 March to 3 December 1990. The objectives of this test were: to qualify design and process changes on flight hardware using a tie ply between the redesigned solid rocket motor steel case and the nitrile butadiene rubber insulation over the tang capture features; to qualify the use of methyl ethyl ketone in the tang flap region to reduce voids; and to determine if holes in the separator film reduce voids in the tang flap region. The tie ply is intended to aid insulation flow during the insulation cure process, and thus reduce or eliminate edge unbonds. Methyl ethyl ketone is intended to reduce voids in the tang flap area by providing better tacking characteristics. The perforated film was intended to provide possible vertical breathe paths to reduce voids in the tang area. Tang tie ply testing consisted of 270 deg of the tang circumference using a new layup method and 90 deg of the tang circumference using the current layup methods. Tie ply process success was defined as a reduction of insulation unbonds. Lack of any insulation edge unbonds on the tang area where the new process was used, and the presence of 17 unbonds with the current process, proves the test to be a success. Successful completion of this test has qualified the new processes.

Studies of Surface Charging of Polymers by Indirect Triboelectrification

NASA Astrophysics Data System (ADS)

Mantovani, James; Calle, Carlos; Groop, Ellen; Buehler, Martin

2001-03-01

Charge is known to develop on the surface of an insulating polymer by frictional charging through direct physical contact with another material. We will present results of recent triboelectrification studies of polymer surfaces that utilized an indirect method of frictional charging. This method first involves placing a grounded thin metal foil in stationary contact over the polymer surface. The exposed metal foil is then rubbed with the surface of the material that generates the triboelectric charge. Data is presented for five types of polymers: fiberglass/epoxy, polycarbonate (Lexan), polytetraflouroethylene (Teflon), Rulon J, and polymethylmethacrylate (PMMA, Lucite). The amount of charge that develops on an insulator's surface is measured using the MECA Electrometer, which was developed jointly by NASA Kennedy Space Center and the Jet Propulsion Laboratory to study the electrostatic properties of soil on the surface of Mars. Even though the insulator's surface is electrically shielded from the rubbing material by the grounded metal foil, charge measurements obtained by the MECA Electrometer after the metal foil is separated from the insulator's surface reveal that the insulator's surface does accumulate charge by indirect frictional charging. A possible explanation of the observations will be presented based on a simple contact barrier model.

Thin-layer thermal insulation coatings based on high-filled spheroplastics with polyorganosiloxane binder

NASA Astrophysics Data System (ADS)

Chukhlanov, V. Yu; Selivanov, O. G.; Trifonova, T. A.; Ilina, M. E.; Chukhlanova, N. V.

2017-10-01

Thermal insulation coatings, based on polyorganosiloxane as a binder and hollow glass microspheres, have been studied in this research. The developed materials are widely applied in various branches of science and engineering basically in construction. Components interaction processes are comprehensively studied. Spraying production methods of thin layer thermal insulation coatings have been researched. Ideal technological parameters for polyorganosiloxane coatings hardening depending on components ratio, ambient temperature, solvent and curative concentration have been determined. Stress related characteristics of constructional energy saving materials containing polyorganosiloxane have been researched. Components structure and ratio concerning compound extension strength properties have been revealed. Substantiation of Danneberg model application for the strength characteristics enhancing, when hollow microspheres are introduced, has been suggested. Thermal properties of coating thermal insulation have been studied. To research these characteristics standard methods applying devices IT-S-400 and IT-λ-400 have been chosen. Filler concentration increase was stated to decrease the composition heat conductivity coefficient and to the reduction of temperature dependence of this index. The authors suggested to employ the developed thermal insulation materials for construction and power engineering facilities operating under high temperature and other unfavorable environment.

Effective plasmonic mode-size converter.

PubMed

Park, Hae-Ryeong; Park, Jong-Moon; Kim, Min-su; Ju, Jung Jin; Son, Jung-Han; Lee, Myung-Hyun

2011-10-24

Plasmonic mode-size converters (PMSCs) for long-range surface plasmon polaritons (LR-SPPs) at the wavelength of 1.55 μm are presented. The PMSC is composed of an insulator-metal-insulator waveguide (IMI-W), a laterally tapered insulator-metal-insulator-metal-insulator waveguide (LT-IMIMI-W), and an IMIMI-W in series. The mode-intensity sizes of the LR-SPPs for the IMI-W and the IMIMI-W were not only calculated using a finite element method but were also experimentally measured. The propagation losses of the IMI-W and the IMIMI-W as well as the coupling losses between them were analyzed by the cut-back method to investigate the effect of LT-IMIMI-Ws. By using the PMSC with a ~27 ° angled LT-IMIMI-W, the coupling loss between a polarization-maintaining fiber and a 3 μm-wide IMIMI-W was reduced by ~3.4 dB. Moreover, the resulting mode-intensity in the output of the PMSC was squeezed to ~35% of the mode-intensity in the input IMI-W. The PMSC may be potentially useful for bridging micro- to nano-plasmonic integrated circuits. © 2011 Optical Society of America

Mott Transition of MnO under Pressure: A Comparison of Correlated Band Theories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kasinathan, Deepa; Kunes, Jan; Koepernik, K

The electronic structure, magnetic moment, and volume collapse of MnO under pressure are obtained from four different correlated band theory methods; local density approximation+Hubbard U (LDA+U), pseudopotential self-interaction correction (pseudo-SIC), the hybrid functional (combined local exchange plus Hartree-Fock exchange), and the local spin density SIC (SIC-LSD) method. Each method treats correlation among the five Mn 3d orbitals (per spin), including their hybridization with three O 2p orbitals in the valence bands and their changes with pressure. The focus is on comparison of the methods for rock salt MnO (neglecting the observed transition to the NiAs structure in the 90-100 GPamore » range). Each method predicts a first-order volume collapse, but with variation in the predicted volume and critical pressure. Accompanying the volume collapse is a moment collapse, which for all methods is from high-spin to low-spin ((5/2){yields}(1/2)), not to nonmagnetic as the simplest scenario would have. The specific manner in which the transition occurs varies considerably among the methods: pseudo-SIC and SIC-LSD give insulator-to-metal, while LDA+U gives insulator-to-insulator and the hybrid method gives an insulator-to-semimetal transition. Projected densities of states above and below the transition are presented for each of the methods and used to analyze the character of each transition. In some cases the rhombohedral symmetry of the antiferromagnetically ordered phase clearly influences the character of the transition.« less

Processing of insulators and semiconductors

DOEpatents

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.

A New Numerical Method for Z2 Topological Insulators with Strong Disorder

NASA Astrophysics Data System (ADS)

Akagi, Yutaka; Katsura, Hosho; Koma, Tohru

2017-12-01

We propose a new method to numerically compute the Z2 indices for disordered topological insulators in Kitaev's periodic table. All of the Z2 indices are derived from the index formulae which are expressed in terms of a pair of projections introduced by Avron, Seiler, and Simon. For a given pair of projections, the corresponding index is determined by the spectrum of the difference between the two projections. This difference exhibits remarkable and useful properties, as it is compact and has a supersymmetric structure in the spectrum. These properties enable highly efficient numerical calculation of the indices of disordered topological insulators. The method, which we propose, is demonstrated for the Bernevig-Hughes-Zhang and Wilson-Dirac models whose topological phases are characterized by a Z2 index in two and three dimensions, respectively.

Two-phase mixed media dielectric with macro dielectric beads for enhancing resistivity and breakdown strength

DOEpatents

Falabella, Steven; Meyer, Glenn A; Tang, Vincent; Guethlein, Gary

2014-06-10

A two-phase mixed media insulator having a dielectric fluid filling the interstices between macro-sized dielectric beads packed into a confined volume, so that the packed dielectric beads inhibit electro-hydrodynamically driven current flows of the dielectric liquid and thereby increase the resistivity and breakdown strength of the two-phase insulator over the dielectric liquid alone. In addition, an electrical apparatus incorporates the two-phase mixed media insulator to insulate between electrical components of different electrical potentials. And a method of electrically insulating between electrical components of different electrical potentials fills a confined volume between the electrical components with the two-phase dielectric composite, so that the macro dielectric beads are packed in the confined volume and interstices formed between the macro dielectric beads are filled with the dielectric liquid.

Improvement of sound insulation performance of double-glazed windows by using viscoelastic connectors

NASA Astrophysics Data System (ADS)

Takahashi, D.; Sawaki, S.; Mu, R.-L.

2016-06-01

A new method for improving the sound insulation performance of double-glazed windows is proposed. This technique uses viscoelastic materials as connectors between the two glass panels to ensure that the appropriate spacing is maintained. An analytical model that makes it possible to discuss the effects of spacing, contact area, and viscoelastic properties of the connectors on the performance in terms of sound insulation is developed. The validity of the model is verified by comparing its results with measured data. The numerical experiments using this analytical model showed the importance of the ability of the connectors to achieve the appropriate spacing and their viscoelastic properties, both of which are necessary for improving the sound insulation performance. In addition, it was shown that the most effective factor is damping: the stronger the damping, the more the insulation performance increases.

Method of making silicon on insalator material using oxygen implantation

DOEpatents

Hite, Larry R.; Houston, Ted; Matloubian, Mishel

1989-01-01

The described embodiments of the present invention provide a semiconductor on insulator structure providing a semiconductor layer less susceptible to single event upset errors (SEU) due to radiation. The semiconductor layer is formed by implanting ions which form an insulating layer beneath the surface of a crystalline semiconductor substrate. The remaining crystalline semiconductor layer above the insulating layer provides nucleation sites for forming a crystalline semiconductor layer above the insulating layer. The damage caused by implantation of the ions for forming an insulating layer is left unannealed before formation of the semiconductor layer by epitaxial growth. The epitaxial layer, thus formed, provides superior characteristics for prevention of SEU errors, in that the carrier lifetime within the epitaxial layer, thus formed, is less than the carrier lifetime in epitaxial layers formed on annealed material while providing adequate semiconductor characteristics.

Decomposition Mechanism of C5F10O: An Environmentally Friendly Insulation Medium.

PubMed

Zhang, Xiaoxing; Li, Yi; Xiao, Song; Tang, Ju; Tian, Shuangshuang; Deng, Zaitao

2017-09-05

SF 6 , the most widely used electrical-equipment-insulation gas, has serious greenhouse effects. C 5 F 10 O has attracted much attention as an alternative gas in recent two years, but the environmental impact of its decomposition products is unclear. In this work, the decomposition characteristics of C 5 F 10 O were studied based on gas chromatography-mass spectrometry and density functional theory. We found that the amount of decomposition products of C 5 F 10 O, namely, CF 4 , C 2 F 6 , C 3 F 6 , C 3 F 8 , C 4 F 10 , and C 6 F 14 , increased with increased number of discharges. Under a high-energy electric field, the C-C bond of C 5 F 10 O between carbonyl carbon and α-carbon atoms was most likely to break and generate CF 3 CO•, C 3 F 7 • or C 3 F 7 CO•, CF 3 • free radicals. CF 3 •, and C 3 F 7 • free radicals produced by the breakage more easily recombined to form small molecular products. By analyzing the ionization parameters, toxicity, and environmental effects of C 5 F 10 O and its decomposition products, we found that C 5 F 10 O gas mixtures exhibit great decomposition and environmental characteristics with low toxicity, with great potential to replace SF 6 .

Fabrication and characterization of NiO based metal-insulator-metal diode using Langmuir-Blodgett method for high frequency rectification

NASA Astrophysics Data System (ADS)

Azad, Ibrahim; Ram, Manoj K.; Goswami, D. Yogi; Stefanakos, Elias

2018-04-01

Thin film metal-insulator-metal (MIM) diodes have attracted significant attention for use in infrared energy harvesting and detection applications. As demonstrated over the past decades, MIM or metal-insulator-insulator-metal (MIIM) diodes can operate at the THz frequencies range by quantum tunneling of electrons. The aim of this work is to synthesize required ultra-thin insulating layers and fabricate MIM diodes using the Langmuir-Blodgett (LB) technique. The nickel stearate (NiSt) LB precursor film was deposited on glass, silicon (Si), ITO glass and gold coated silicon substrates. The photodesorption (UV exposure) and the thermodesorption (annealing at 100 °C and 350 °C) methods were used to remove organic components from the NiSt LB film and to achieve a uniform homogenous nickel oxide (NiO) film. These ultrathin NiO films were characterized by EDS, AFM, FTIR and cyclic voltammetry methods, respectively. The MIM diode was fabricated by depositing nickel (Ni) on the NiO film, all on a gold (Au) plated silicon (Si) substrate. The current (I)-voltage (V) characteristics of the fabricated diode were studied to understand the conduction mechanism assumed to be tunneling of electron through the ultra-thin insulating layer. The sensitivity of the diode was measured to be as high as 35 V-1. The diode resistance was ˜100 ohms (at a bias voltage of 0.60 V), and the rectification ratio was about 22 (for a signal voltage of ±200 mV). At the bias point, the diode response demonstrated significant non-linearity and high asymmetry, which are very desirable characteristics for applications in infrared detection and harvesting.

Non-Asbestos Insulation Testing Using a Plasma Torch

NASA Technical Reports Server (NTRS)

Morgan, R. E.; Prince, A. S.; Selvidge, S. A.; Phelps, J.; Martin, C. L.; Lawrence, T. W.

2000-01-01

Insulation obsolescence issues are a major concern for the Reusable Solid Rocket Motor (RSRM). As old sources of raw materials disappear, new sources must be found and qualified. No simple, inexpensive test presently exists for predicting the erosion performance of a candidate insulation in the full-scale motor, Large motor tests cost million of dollars and therefore can only be used on a few very select candidates. There is a need for a simple, low cost method of screening insulation performance that can simulate some of the different erosion environments found in the RSRM. This paper describes a series of erosion tests on two different non-asbestos insulation formulations, a KEVLAR(registered) fiber-filled and a carbon fiber-filled insulation containing Ethylene-Propylene-Diene Monomer (EPDM) rubber as the binder. The test instrument was a plasma torch device. The two main variables investigated were heat flux and alumina particle impingement concentration. Statistical analysis revealed that the two different formulations had very different responses to the main variable. The results of this work indicate that there may be fundamental differences in how these insulation formulations perform in the motor operating environment. The plasma torch appears to offer a low-cost means of obtaining a fundamental understanding of insulation response to critical factors in a series of statistically designed experiments.

Interventional MRI: tapering improves the distal sensitivity of the loopless antenna.

PubMed

Qian, Di; El-Sharkawy, AbdEl-Monem M; Atalar, Ergin; Bottomley, Paul A

2010-03-01

The "loopless antenna" is an interventional MRI detector consisting of a tuned coaxial cable and an extended inner conductor or "whip". A limitation is the poor sensitivity afforded at, and immediately proximal to, its distal end, which is exacerbated by the extended whip length when the whip is uniformly insulated. It is shown here that tapered insulation dramatically improves the distal sensitivity of the loopless antenna by pushing the current sensitivity toward the tip. The absolute signal-to-noise ratio is numerically computed by the electromagnetic method-of-moments for three resonant 3-T antennae with no insulation, uniform insulation, and with linearly tapered insulation. The analysis shows that tapered insulation provides an approximately 400% increase in signal-to-noise ratio in trans-axial planes 1 cm from the tip and a 16-fold increase in the sensitive area as compared to an equivalent, uniformly insulated antenna. These findings are directly confirmed by phantom experiments and by MRI of an aorta specimen. The results demonstrate that numerical electromagnetic signal-to-noise ratio analysis can accurately predict the loopless detector's signal-to-noise ratio and play a central role in optimizing its design. The manifold improvement in distal signal-to-noise ratio afforded by redistributing the insulation should improve the loopless antenna's utility for interventional MRI. (c) 2010 Wiley-Liss, Inc.

In Situ Corrosion and Heat Loss Assessment of Two Nonstandard Underground Heat Distribution System Piping Designs

DTIC Science & Technology

2011-06-01

of this specific design consists of a carrier pipe, carrier pipe insulation ( mineral wool ), an annular air space, steel casing, a layer of exterior...excavation site agree with Perma-Pipe “Multi-Therm 500” nominal specs for 10” carrier with 2” mineral wool insulation. 3. Conduit Temperature: Supply...the ASHRAE calculation method or by manufacturer performance claims. MEC is reasonably certain that the mineral wool insulation used by the

Method of preparing a powdered, electrically insulative separator for use in an electrochemical cell

DOEpatents

Cooper, Tom O.; Miller, William E.

1978-01-01

A secondary electrochemical cell includes electrodes separated by a layer of electrically insulative powder. The powder includes refractory materials selected from the oxides and nitrides of metals and metaloids. The powdered refractory material, blended with electrolyte particles, is compacted as layers onto an electrode to form an integral electrode structure and assembled into the cell. The assembled cell is heated to its operating temperature leaving porous layers of electrically insulative, refractory particles, containing molten electrolyte between the electrodes.

Disorder effect on the Friedel oscillations in a one-dimensional Mott insulator

NASA Astrophysics Data System (ADS)

Weiss, Y.; Goldstein, M.; Berkovits, R.

2007-07-01

The Friedel oscillations resulting from coupling a quantum dot to one edge of a disordered one-dimensional wire in the Mott insulator regime are calculated numerically using the density matrix renormalization group method. By investigating the influence of a constant weak disorder on the Friedel oscillations decay we find that the effect of disorder is reduced by increasing the interaction strength. This behavior is opposite to the recently reported influence of disorder in the Anderson insulator regime.

Determination of Insulator-to-Semiconductor Transition in Sol-Gel Oxide Semiconductors Using Derivative Spectroscopy.

PubMed

Lee, Woobin; Choi, Seungbeom; Kim, Kyung Tae; Kang, Jingu; Park, Sung Kyu; Kim, Yong-Hoon

2015-12-23

We report a derivative spectroscopic method for determining insulator-to-semiconductor transition during sol-gel metal-oxide semiconductor formation. When an as-spun sol-gel precursor film is photochemically activated and changes to semiconducting state, the light absorption characteristics of the metal-oxide film is considerable changed particularly in the ultraviolet region. As a result, a peak is generated in the first-order derivatives of light absorption ( A' ) vs. wavelength (λ) plots, and by tracing the peak center shift and peak intensity, transition from insulating-to-semiconducting state of the film can be monitored. The peak generation and peak center shift are described based on photon-energy-dependent absorption coefficient of metal-oxide films. We discuss detailed analysis method for metal-oxide semiconductor films and its application in thin-film transistor fabrication. We believe this derivative spectroscopy based determination can be beneficial for a non-destructive and a rapid monitoring of the insulator-to-semiconductor transition in sol-gel oxide semiconductor formation.

Technique for Evaluating the Erosive Properties of Ablative Internal Insulation Materials

NASA Technical Reports Server (NTRS)

McComb, J. C.; Hitner, J. M.

1989-01-01

A technique for determining the average erosion rate versus Mach number of candidate internal insulation materials was developed for flight motor applications in 12 inch I.D. test firing hardware. The method involved the precision mounting of a mechanical measuring tool within a conical test cartridge fabricated from either a single insulation material or two non-identical materials each of which constituted one half of the test cartridge cone. Comparison of the internal radii measured at nine longitudinal locations and between eight to thirty two azimuths, depending on the regularity of the erosion pattern before and after test firing, permitted calculation of the average erosion rate and Mach number. Systematic criteria were established for identifying erosion anomalies such as the formation of localized ridges and for excluding such anomalies from the calculations. The method is discussed and results presented for several asbestos-free materials developed in-house for the internal motor case insulation in solid propellant rocket motors.

Forecasting of high voltage insulation performance: Testing of recommended potting materials and of capacitors

NASA Technical Reports Server (NTRS)

Bever, R. S.

1984-01-01

Nondestructive high voltage test techniques (mostly electrical methods) are studied to prevent total or catastrophic breakdown of insulation systems under applied high voltage in space. Emphasis is on the phenomenon of partial breakdown or partial discharge (P.D.) as a symptom of insulation quality, notably partial discharge testing under D.C. applied voltage. Many of the electronic parts and high voltage instruments in space experience D.C. applied stress in service, and application of A.C. voltage to any portion thereof would be prohibited. Suggestions include: investigation of the ramp test method for D.C. partial discharge measurements; testing of actual flight-type insulation specimen; perfect plotting resin samples with controlled defects for test; several types of plotting resins and recommendations of the better ones from the electrical characteristics; thermal and elastic properties are also considered; testing of commercial capaciters; and approximate acceptance/rejection/rerating criteria for sample test elements for space use, based on D.C. partial discharge.

Experimental foundation of the Gabor-Nelson theory applied to boundaries which are non-insulating.

PubMed

Troquet, J; Lambin, P; Nelson, C V

1985-06-07

In order to found the application of the Gabor-Nelson theory to non-insulating boundaries, we have used a network which we have divided into two parts: a core energized by a source sink pair and an appendage, the conductivity of which may or may not differ from that of the core. By ignoring the appendage and by applying the Gabor-Nelson method to the restricted perimeter as if it were totally insulating, we stress the errors made in computing the dipole strength, orientation and position and how they are influenced by the dipole eccentricity, by its orientation with respect to the junction between the added portion and the core, and by a change in conductivity between the same compartments. Finally, we restore the dipole characteristics by using the appropriate correction derived from theory. Comparing the later results to those obtained by applying the Gabor-Nelson method to the whole insulating boundary leads to the conclusion that the correction is founded and must be taken into account.

Thermal transport across metal–insulator interface via electron–phonon interaction.

PubMed

Zhang, Lifa; Lü, Jing-Tao; Wang, Jian-Sheng; Li, Baowen

2013-11-06

The thermal transport across a metal–insulator interface can be characterized by electron–phonon interaction through which an electron lead is coupled to a phonon lead if phonon–phonon coupling at the interface is very weak. We investigate the thermal conductance and rectification between the electron part and the phonon part using the nonequilibrium Green's function method. It is found that the thermal conductance has a nonmonotonic behavior as a function of average temperature or the coupling strength between the phonon leads in the metal part and the insulator part. The metal–insulator interface shows a clear thermal rectification effect, which can be reversed by a change in average temperature or the electron–phonon coupling.

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

NASA Technical Reports Server (NTRS)

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.

Investigation of Insulation Materials for Future Radioisotope Power Systems

NASA Technical Reports Server (NTRS)

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.

Building America Case Study: Initial and Long-Term Movement of Cladding Installed Over Exterior Rigid Insulation (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Changes in the International Energy Conservation Code (IECC) from 2009 to 2012 have resulted in the use of exterior rigid insulation becoming part of the prescriptive code requirements. With more jurisdictions adopting the 2012 IECC builders are going to finding themselves required to incorporate exterior insulation in the construction of their exterior wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location. However, there has beenmore » a significant resistance to its widespread implementation due to a lack of research and understanding of the mechanisms involved and potential creep effects of the assembly under the sustained dead load of a cladding. This research was an extension on previous research conducted by BSC in 2011, and 2012. Each year the understanding of the system discrete load component interactions, as well as impacts of environmental loading has increased. The focus of the research was to examine more closely the impacts of screw fastener bending on the total system capacity, effects of thermal expansion and contraction of materials on the compressive forces in the assembly, as well as to analyze a full years worth of cladding movement data from assemblies constructed in an exposed outdoor environment.« less

Experimental measurements concerning the stator insulation partial discharge level of a hydro-generator of high power

NASA Astrophysics Data System (ADS)

Haţiegan, C.; Răduca, E.; Popescu, C.; Hamat, C. O.; Băra, A.; Anghel, D.; Pîrşan, D. A.

2018-01-01

The paper presents a determining and evaluating method from an experimental point of view of the partial discharges level from the insulation of the stator of a synchronous hydro-generator of high power that appear at different temperatures. The temperature is measured directly on the coil with placed thermo-resistant elements between the superior and inferior bars. Also, the level of partial discharges with the coil age in a cold state, at the temperature level of the surrounding environment from within the stator, but also in a warm state at different temperatures, is measured. Through this method there is created the possibility of highlighting some eventual degradations of the coil insulation of a hydro-generator.

Miniature traveling wave tube and method of making

NASA Technical Reports Server (NTRS)

Kosmahl, Henry G. (Inventor)

1989-01-01

It is an object of the invention to provide a miniature traveling wave tube which will have most of the advantages of solid state circuitry but with higher efficiency and without being highly sensitive to temperature and various types of electromagnetic radiation and subatomic particles as are solid state devices. The traveling wave tube which is about 2.5 cm in length includes a slow wave circuit (SWS) comprising apertured fins with a top cover which is insulated from the fins by strips or rungs of electrically insulating, dielectric material. Another object of the invention is to construct a SWS of extremely small size by employing various grooving or etching methods and by providing insulating strips or rungs by various deposition and masking techniques.

Bioavailability of HBCD/TBB/TBPH from dust and oil vehicles in Sprague-Dawley rats

USDA-ARS?s Scientific Manuscript database

Recent data have revealed that homes, offices and cars are often more polluted with environmental contaminants than the outdoors due to high use of textiles, electronics, and insulation that are treated with brominated flame retardants (BFRs). BFRs volatilize and/or weather from consumer products a...

Environmental and Sustainable Technology Evaluations (ESTE): Verification of Microbial Resistant Building Materials

EPA Science Inventory

This is an ESTE project summary brief. Many of the finished interior surfaces of homes and buildings are composed of materials that are prone to mold growth. These surfaces include gypsum board, wood flooring, insulation, and components of the heating and air conditioning system...

40 CFR 426.17 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... control technology (BCT). 426.17 Section 426.17 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Insulation Fiberglass... by the application of the best conventional pollutant control technology (BCT). Except as provided in...

Energy Management System Successful in Indiana Elementary School.

ERIC Educational Resources Information Center

School Business Affairs, 1984

1984-01-01

The new Oregon-Davis Elementary School in rural Indiana embodies state-of-the-art energy management. Its environmental systems include thorough insulation, dual heating and cooling equipment for flexible loads, and decentralized computer controls. A heat recovery unit and variable-air-volume discharge ducts also contribute to conservation. (MCG)

ULTRAFINE CARBON PARTICLES INDUCE INTERLEUKIN-8 GENE TRANSCRIPTION AND P38 MAPK ACTIVATION IN NORMAL BRONCHIAL EPITHELIAL CELLS

EPA Science Inventory

Epidemiological studies suggest that ultrafine particles contribute to particulate matter-induced adverse health effects. Interleukin (IL)-8 is an important proinflammatory cytokine in the human lung that is induced in respiratory cells exposed to a variety of environmental insul...

Carbon nanotube nanoelectrode arrays

DOEpatents

Ren, Zhifeng; Lin, Yuehe; Yantasee, Wassana; Liu, Guodong; Lu, Fang; Tu, Yi

2008-11-18

The present invention relates to microelectode arrays (MEAs), and more particularly to carbon nanotube nanoelectrode arrays (CNT-NEAs) for chemical and biological sensing, and methods of use. A nanoelectrode array includes a carbon nanotube material comprising an array of substantially linear carbon nanotubes each having a proximal end and a distal end, the proximal end of the carbon nanotubes are attached to a catalyst substrate material so as to form the array with a pre-determined site density, wherein the carbon nanotubes are aligned with respect to one another within the array; an electrically insulating layer on the surface of the carbon nanotube material, whereby the distal end of the carbon nanotubes extend beyond the electrically insulating layer; a second adhesive electrically insulating layer on the surface of the electrically insulating layer, whereby the distal end of the carbon nanotubes extend beyond the second adhesive electrically insulating layer; and a metal wire attached to the catalyst substrate material.

Dielectrophoretic systems without embedded electrodes

DOEpatents

Cummings, Eric B [Livermore, CA; Singh, Anup K [San Francisco, CA

2006-03-21

Method and apparatus for dielectrophoretic separation of particles in a fluid based using array of insulating structures arranged in a fluid flow channel. By utilizing an array of insulating structures, a spatially inhomogeneous electric field is created without the use of the embedded electrodes conventionally employed for dielectrophoretic separations. Moreover, by using these insulating structures a steady applied electric field has been shown to provide for dielectrophoresis in contrast to the conventional use of an alternating electric field. In a uniform array of posts, dielectrophoretic effects have been produced flows having significant pressure-driven and electrokinetic transport. Above a threshold applied electric field, filaments of concentrated and rarefied particles appear in the flow as a result of dielectrophoresis. Above a higher threshold applied voltage, dielectrophoresis produces zones of highly concentrated and immobilized particles. These patterns are strongly influenced by the angle of the array of insulating structures with respect to the mean applied electric field and the shape of the insulating structures.

Spark Plug Defects and Tests

NASA Technical Reports Server (NTRS)

Silsbee, F B; Loeb, L B; Sawyer, L G; Fonseca, E L; Dickinson, H C; Agnew, P G

1920-01-01

The successful operation of the spark plug depends to a large extent on the gas tightness of the plug. Part 1 of this report describes the method used for measuring the gas tightness of aviation spark plugs. Part 2 describes the methods used in testing the electrical conductivity of the insulation material when hot. Part 3 describes the testing of the cold dielectric strength of the insulation material, the resistance to mechanical shock, and the final engine test.

A study of numerical methods for computing reentry trajectories for shuttle-type space vehicles

NASA Technical Reports Server (NTRS)

1972-01-01

The reuseable exterior insulation system (REI) is studied to determine the optimal reentry trajectory for a space shuttle, which minimizes the heat input to the fuselage. The REI is composed of titanium, covered by a surface insulation material. The method of perturbation functions was used to generate the trajectories, and proved to be an effective technique for generating families of solutions, once an initial trajectory has been obtained.

Measuring the lateral charge-carrier mobility in metal-insulator-semiconductor capacitors via Kelvin-probe.

PubMed

Milotti, Valeria; Pietsch, Manuel; Strunk, Karl-Philipp; Melzer, Christian

2018-01-01

We report a Kelvin-probe method to investigate the lateral charge-transport properties of semiconductors, most notably the charge-carrier mobility. The method is based on successive charging and discharging of a pre-biased metal-insulator-semiconductor stack by an alternating voltage applied to one edge of a laterally confined semiconductor layer. The charge carriers spreading along the insulator-semiconductor interface are directly measured by a Kelvin-probe, following the time evolution of the surface potential. A model is presented, describing the device response for arbitrary applied biases allowing the extraction of the lateral charge-carrier mobility from experimentally measured surface potentials. The method is tested using the organic semiconductor poly(3-hexylthiophene), and the extracted mobilities are validated through current voltage measurements on respective field-effect transistors. Our widely applicable approach enables robust measurements of the lateral charge-carrier mobility in semiconductors with weak impact from the utilized contact materials.

Measuring the lateral charge-carrier mobility in metal-insulator-semiconductor capacitors via Kelvin-probe

NASA Astrophysics Data System (ADS)

Milotti, Valeria; Pietsch, Manuel; Strunk, Karl-Philipp; Melzer, Christian

2018-01-01

We report a Kelvin-probe method to investigate the lateral charge-transport properties of semiconductors, most notably the charge-carrier mobility. The method is based on successive charging and discharging of a pre-biased metal-insulator-semiconductor stack by an alternating voltage applied to one edge of a laterally confined semiconductor layer. The charge carriers spreading along the insulator-semiconductor interface are directly measured by a Kelvin-probe, following the time evolution of the surface potential. A model is presented, describing the device response for arbitrary applied biases allowing the extraction of the lateral charge-carrier mobility from experimentally measured surface potentials. The method is tested using the organic semiconductor poly(3-hexylthiophene), and the extracted mobilities are validated through current voltage measurements on respective field-effect transistors. Our widely applicable approach enables robust measurements of the lateral charge-carrier mobility in semiconductors with weak impact from the utilized contact materials.

The improvement of thermal characteristics of autoclave aerated concrete for energy efficient high-rise buildings application

NASA Astrophysics Data System (ADS)

Khavanov, Pavel; Fomina, Ekaterina; Kozhukhova, Natalia

2018-03-01

Nowadays, the problem of energy saving is very relevant. One of the ways to reduction energy consumption in construction materials production and construction of civil and industrial high-rise buildings is the application of claddings with heat-insulating performance. The concept of energy efficiency of high-rise buildings is closely related to environmental aspect and sustainability of applied construction materials; reducing service costs; energy saving and microclimate comfortability. A complexity of architectural and structural design as well as aesthetic characteristics of construction materials are also should be considered. The high interest focused on materials with combined properties. This work is oriented on the study of energy efficiency of buildings by improving heat-insulation and strength performance of autoclave aerated concrete. The applied method of sulfate activation of lime allows monitoring phase and structure formation in aerated concrete. The optimal mix design of aerated concrete with the compressive strength up to 8.5 MPa and decreased density up to 760 kg/m3 was proposed. Analysis of structure at macro-and microscale was performed as well as the criteria of an optimal porosity formation was considered a number, size, shape of pore and density of interior partition. SEM analysis and BET method were performed in this research work. The research results demonstrated the correlation between structure and vapor permeability resistance, also it was found that the increase of strength can lead to reduction of thermal conductivity.

Investigation of Gas-Sensing Property of Acid-Deposited Polyaniline Thin-Film Sensors for Detecting H2S and SO2

PubMed Central

Dong, Xingchen; Zhang, Xiaoxing; Wu, Xiaoqing; Cui, Hao; Chen, Dachang

2016-01-01

Latent insulation defects introduced in manufacturing process of gas-insulated switchgears can lead to partial discharge during long-time operation, even to insulation fault if partial discharge develops further. Monitoring of decomposed components of SF6, insulating medium of gas-insulated switchgear, is a feasible method of early-warning to avoid the occurrence of sudden fault. Polyaniline thin-film with protonic acid deposited possesses wide application prospects in the gas-sensing field. Polyaniline thin-film sensors with only sulfosalicylic acid deposited and with both hydrochloric acid and sulfosalicylic acid deposited were prepared by chemical oxidative polymerization method. Gas-sensing experiment was carried out to test properties of new sensors when exposed to H2S and SO2, two decomposed products of SF6 under discharge. The gas-sensing properties of these two sensors were compared with that of a hydrochloric acid deposited sensor. Results show that the hydrochloric acid and sulfosalicylic acid deposited polyaniline thin-film sensor shows the most outstanding sensitivity and selectivity to H2S and SO2 when concentration of gases range from 10 to 100 μL/L, with sensitivity changing linearly with concentration of gases. The sensor also possesses excellent long-time and thermal stability. This research lays the foundation for preparing practical gas-sensing devices to detect H2S and SO2 in gas-insulated switchgears at room temperature. PMID:27834895

Material-controlled dynamic vacuum insulation

DOEpatents

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.

Variably insulating portable heater/cooler

DOEpatents

Potter, Thomas F.

1998-01-01

A compact vacuum insulation panel 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.

Material-controlled dynamic vacuum insulation

DOEpatents

Benson, David K.; Potter, Thomas F.

1996-10-08

A compact vacuum insulation panel 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.

Radiation-controlled dynamic vacuum insulation

DOEpatents

Benson, David K.; Potter, Thomas F.

1995-01-01

A compact vacuum insulation panel 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 that 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.

Radiation-controlled dynamic vacuum insulation

DOEpatents

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

1995-07-18

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 that 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.

Variably insulating portable heater/cooler

DOEpatents

Potter, T.F.

1998-09-29

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.

Study of acoustic emission during mechanical tests of large flight weight tank structure

NASA Technical Reports Server (NTRS)

Nakamura, Y.; Mccauley, B. O.; Veach, C. L.

1972-01-01

A polyphenylane oxide insulated, flight weight, subscale, aluminum tank was monitored for acoustic emissions during a proof test and during 100 cycles of environmental test simulating space flights. The use of a combination of frequency filtering and appropriate spatial filtering to reduce background noise was found to be sufficient to detect acoustic emission signals of relatively small intensity expected from subcritical crack growth in the structure. Several emission source locations were identified, including the one where a flaw was detected by post-test X-ray inspections. For most source locations, however, post-test inspections did not detect flaws; this was partially attributed to the higher sensitivity of the acoustic emission technique than any other currently available NDT method for detecting flaws.

Thermal insulation and clothing area factors of typical Arabian Gulf clothing ensembles for males and females: measurements using thermal manikins.

PubMed

Al-ajmi, F F; Loveday, D L; Bedwell, K H; Havenith, G

2008-05-01

The thermal insulation of clothing is one of the most important parameters used in the thermal comfort model adopted by the International Standards Organisation (ISO) [BS EN ISO 7730, 2005. Ergonomics of the thermal environment. Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria. International Standardisation Organisation, Geneva.] and by ASHRAE [ASHRAE Handbook, 2005. Fundamentals. Chapter 8. American Society of Heating Refrigeration and Air-conditioning Engineers, Inc., 1791 Tullie Circle N.E., Atlanta, GA.]. To date, thermal insulation values of mainly Western clothing have been published with only minimal data being available for non-Western clothing. Thus, the objective of the present study is to measure and present the thermal insulation (clo) values of a number of Arabian Gulf garments as worn by males and females. The clothing ensembles and garments of Arabian Gulf males and females presented in this study are representative of those typically worn in the region during both summer and winter seasons. Measurements of total thermal insulation values (clo) were obtained using a male and a female shape thermal manikin in accordance with the definition of insulation as given in ISO 9920. In addition, the clothing area factors (f cl) determined in two different ways were compared. The first method used a photographic technique and the second a regression equation as proposed in ISO 9920, based on the insulation values of Arabian Gulf male and female garments and ensembles as they were determined in this study. In addition, fibre content, descriptions and weights of Arabian Gulf clothing have been recorded and tabulated in this study. The findings of this study are presented as additions to the existing knowledge base of clothing insulation, and provide for the first time data for Arabian Gulf clothing. The analysis showed that for these non-Western clothing designs, the most widely used regression calculation of f cl is not valid. However, despite the very large errors in f cl made with the regression method, the errors this causes in the intrinsic clothing insulation value, I cl, are limited.

Plasma vitrification of asbestos fibers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Camacho, S.L.

Asbestos is a mineral in the form of long, thread-like fibers. Asbestos fibers have been among the best insulators of pipes, boilers, ducts, tanks, etc., in buildings, ships, and industrial furnaces. Over 150,000 metric tons of asbestos were consumed in the United States in 1984. The Environmental Protection Agency has declared asbestos fibers a known human carcinogen. And today, asbestos insulators are being replaced by manmade non-hazardous fibers. Millions of tons of replaced asbestos fiber insulators are in storage, awaiting the demonstration of effective alternative disposal technologies. Plasma vitrification has been demonstrated during May, June and July 1995 as amore » viable, cost-effective, safe technology for asbestos fiber disposal. A low-mass plasma arc heater is submerged under the waste asbestos insulating materials, and the intense heat of the plasma flame heats and melts the fibers. The by-product is dark, non-hazardous glass pellets. The vitrification process renders the asbestos waste safe for use as road construction aggregates or other fill materials. This paper will describe the results of start-up of a 1 ton-per-hour Plasma Mobile Asbestos Vitrification (MAV) Plant at a DOD Site in Port Clinton, Ohio. The Plasma MAV Plant is being demonstrated for the on-site disposal of 1.5 million pounds of Amosite asbestos fibers.« less

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

PubMed

Mandal, A K; Sinha, O P

2017-08-01

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

Low-Melt Poly(Amic Acids) and Polyimides and Their Uses

NASA Technical Reports Server (NTRS)

Parrish, Clyde F. (Inventor); Jolley, Scott T. (Inventor); Gibson, Tracy L. (Inventor); Williams, Martha K. (Inventor); Parks, Steven L. (Inventor)

2014-01-01

Provided are low-melt polyimides and poly(amic acids) (PAAs) for use in repair of electrical wire insulation, flat or ribbon wire harnesses, and flat surfaces comprised of high-performance polymers such as inflatables or solar panels applications. Also provided are methods and devices for repair of electrical insulation.

Low-Melt Poly(amic Acids) and Polyimides and Their Uses

NASA Technical Reports Server (NTRS)

Jolley, Scott T. (Inventor); Gibson, Tracy L. (Inventor); Williams, Martha K. (Inventor); Parrish, Clyde F. (Inventor); Parks, Steven L. (Inventor)

2015-01-01

Provided are low-melt polyimides and poly(amic acids) (PAAs) for use in repair of electrical wire insulation, flat or ribbon wire harnesses, and flat surfaces comprised of high-performance polymers such as inflatables or solar panels applications. Also provided are methods and devices for repair of electrical insulation.

A General Strategy to Achieve Colossal Permittivity and Low Dielectric Loss Through Constructing Insulator/Semiconductor/Insulator Multilayer Structures

NASA Astrophysics Data System (ADS)

Liu, Kai; Sun, Yalong; Zheng, Fengang; Tse, Mei-Yan; Sun, Qingbo; Liu, Yun; Hao, Jianhua

2018-06-01

In this work, we propose a route to realize high-performance colossal permittivity (CP) by creating multilayer structures of insulator/semiconductor/insulator. To prove the new concept, we made heavily reduced rutile TiO2 via annealing route in Ar/H2 atmosphere. Dielectric studies show that the maximum dielectric permittivity ( 3.0 × 104) of our prepared samples is about 100 times higher than that ( 300) of conventional TiO2. The minimum dielectric loss is 0.03 (at 104-105 Hz). Furthermore, CP is almost independent of the frequency (100-106 Hz) and the temperature (20-350 K). We suggest that the colossal permittivity is attributed to the high carrier concentration of the inner TiO2 semiconductor, while the low dielectric loss is due to the presentation of the insulator layer on the surface of TiO2. The method proposed here can be expanded to other material systems, such as semiconductor Si sandwiched by top and bottom insulator layers of Ga2O3.

Surface engineering of ferroelectric polymer for the enhanced electrical performance of organic transistor memory

NASA Astrophysics Data System (ADS)

Kim, Do-Kyung; Lee, Gyu-Jeong; Lee, Jae-Hyun; Kim, Min-Hoi; Bae, Jin-Hyuk

2018-05-01

We suggest a viable surface control method to improve the electrical properties of organic nonvolatile memory transistors. For viable surface control, the surface of the ferroelectric insulator in the memory field-effect transistors was modified using a smooth-contact-curing process. For the modification of the ferroelectric polymer, during the curing of the ferroelectric insulators, the smooth surface of a soft elastomer contacts intimately with the ferroelectric surface. This smooth-contact-curing process reduced the surface roughness of the ferroelectric insulator without degrading its ferroelectric properties. The reduced roughness of the ferroelectric insulator increases the mobility of the organic field-effect transistor by approximately eight times, which results in a high memory on–off ratio and a low-voltage reading operation.

Capability of insulator study by photoemission electron microscopy at SPring-8.

PubMed

Ohkochi, Takuo; Kotsugi, Masato; Yamada, Keisuke; Kawano, Kenji; Horiba, Koji; Kitajima, Fumio; Oura, Masaki; Shiraki, Susumu; Hitosugi, Taro; Oshima, Masaharu; Ono, Teruo; Kinoshita, Toyohiko; Muro, Takayuki; Watanabe, Yoshio

2013-07-01

The observation method of photoemission electron microscopy (PEEM) on insulating samples has been established in an extremely simple way. Surface conductivity is induced locally on an insulating surface by continuous radiation of soft X-rays, and Au films close to the area of interest allow the accumulated charges on the insulated area to be released to ground level. Magnetic domain observations of a NiZn ferrite, local X-ray absorption spectroscopy of sapphire, high-resolution imaging of a poorly conducting Li0.9CoO2 film surface, and Au pattern evaporation on a fine rock particle are demonstrated. Using this technique, all users' experiments on poorly conducting samples have been performed successfully at the PEEM experimental station of SPring-8.

A Method for Optimizing Lightweight-Gypsum Design Based on Sequential Measurements of Physical Parameters

NASA Astrophysics Data System (ADS)

Vimmrová, Alena; Kočí, Václav; Krejsová, Jitka; Černý, Robert

2016-06-01

A method for lightweight-gypsum material design using waste stone dust as the foaming agent is described. The main objective is to reach several physical properties which are inversely related in a certain way. Therefore, a linear optimization method is applied to handle this task systematically. The optimization process is based on sequential measurement of physical properties. The results are subsequently point-awarded according to a complex point criterion and new composition is proposed. After 17 trials the final mixture is obtained, having the bulk density equal to (586 ± 19) kg/m3 and compressive strength (1.10 ± 0.07) MPa. According to a detailed comparative analysis with reference gypsum, the newly developed material can be used as excellent thermally insulating interior plaster with the thermal conductivity of (0.082 ± 0.005) W/(m·K). In addition, its practical application can bring substantial economic and environmental benefits as the material contains 25 % of waste stone dust.

All diamond self-aligned thin film transistor

DOEpatents

Gerbi, Jennifer [Champaign, IL

2008-07-01

A substantially all diamond transistor with an electrically insulating substrate, an electrically conductive diamond layer on the substrate, and a source and a drain contact on the electrically conductive diamond layer. An electrically insulating diamond layer is in contact with the electrically conductive diamond layer, and a gate contact is on the electrically insulating diamond layer. The diamond layers may be homoepitaxial, polycrystalline, nanocrystalline or ultrananocrystalline in various combinations.A method of making a substantially all diamond self-aligned gate transistor is disclosed in which seeding and patterning can be avoided or minimized, if desired.

Insulator photocurrents: Application to dose rate hardening of CMOS/SOI integrated circuits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dupont-Nivet, E.; Coiec, Y.M.; Flament, O.

1998-06-01

Irradiation of insulators with a pulse of high energy x-rays can induce photocurrents in the interconnections of integrated circuits. The authors present, here, a new method to measure and analyze this effect together with a simple model. They also demonstrate that these insulator photocurrents have to be taken into account to obtain high levels of dose-rate hardness with CMOS on SOI integrated circuits, especially flip-flops or memory blocks of ASICs. They show that it explains some of the upsets observed in a SRAM embedded in an ASIC.

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

NASA Astrophysics Data System (ADS)

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

2008-03-01

Thermal conductivity testing under actual-use conditions is a key to understanding how cryogenic thermal insulation systems perform in regard to engineering, economics, and materials factors. The Cryogenics Test Laboratory at NASA's Kennedy Space Center tested a number of bulk-fill insulation materials, including aerogel beads, glass bubbles, and perlite powder, using a new cylindrical cryostat. Boundary temperatures for the liquid nitrogen boiloff method were 78 K and 293 K. Tests were performed as a function of cold vacuum pressure under conditions ranging from high vacuum to no vacuum. Results were compared with those from complementary test methods in the range of 20 K to 300 K. Various testing techniques are required to completely understand the operating performance of a material and to provide data for answers to design engineering questions.

Targeting of sebaceous glands to treat acne by micro-insulated needles with radio frequency in a rabbit ear model.

PubMed

Kwon, Tae-Rin; Choi, Eun Ja; Oh, Chang Taek; Bak, Dong-Ho; Im, Song-I; Ko, Eun Jung; Hong, Hyuck Ki; Choi, Yeon Shik; Seok, Joon; Choi, Sun Young; Ahn, Gun Young; Kim, Beom Joon

2017-04-01

Many studies have investigated the application of micro-insulated needles with radio frequency (RF) to treat acne in humans; however, the use of a micro-insulated needle RF applicator has not yet been studied in an animal model. The purpose of this study was to evaluate the effectiveness of a micro-insulated needle RF applicator in a rabbit ear acne (REA) model. In this study, we investigated the effect of selectively destroying the sebaceous glands using a micro-insulated needle RF applicator on the formation of comedones induced by application of 50% oleic acid and intradermal injection of P. acnes in the orifices of the external auditory canals of rabbits. The effects of the micro-insulated needle RF applicator treatment were evaluated using regular digital photography in addition to 3D Primos imaging evaluation, Skin Visio Meter microscopic photography, and histologic analyses. Use of the micro-insulated needle RF applicator resulted in successful selective destruction of the sebaceous glands and attenuated TNF-alpha release in an REA model. The mechanisms by which micro-insulated needles with RF using 1 MHz exerts its effects may involve inhibition of comedone formation, triggering of the wound healing process, and destruction of the sebaceous glands and papules. The use of micro-insulated needles with RF applicators provides a safe and effective method for improving the appearance of symptoms in an REA model. The current in vivo study confirms that the micro-insulated needle RF applicator is selectively destroying the sebaceous glands. Lasers Surg. Med. 49:395-401, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Cryogenic Insulation System for Soft Vacuum

NASA Technical Reports Server (NTRS)

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

1999-01-01

The development of a cryogenic insulation system for operation under soft vacuum is presented in this paper. Conventional insulation materials for cryogenic applications can be divided into three levels of thermal performance, in terms of apparent thermal conductivity [k-value in milliwatt per meter-kelvin (mW/m-K)]. System k-values below 0.1 can be achieved for multilayer insulation operating at a vacuum level below 1 x 10(exp -4) torr. For fiberglass or powder operating below 1 x 10(exp -3) torr, k-values of about 2 are obtained. For foam and other materials at ambient pressure, k-values around 30 are typical. New industry and aerospace applications require a versatile, robust, low-cost thermal insulation with performance in the intermediate range. The target for the new composite insulation system is a k-value below 4.8 mW/m-K (R-30) at a soft vacuum level (from 1 to 10 torr) and boundary temperatures of approximately 77 and 293 kelvin (K). Many combinations of radiation shields, spacers, and composite materials were tested from high vacuum to ambient pressure using cryostat boiloff methods. Significant improvement over conventional systems in the soft vacuum range was demonstrated. The new layered composite insulation system was also shown to provide key benefits for high vacuum applications as well.

Enhanced Thermal Performance of Mosques in Qatar

NASA Astrophysics Data System (ADS)

Touma, A. Al; Ouahrani, D.

2017-12-01

Qatar has an abundance of mosques that significantly contribute to the increasing energy consumption in the country. Little attention has been given to providing mitigation methods that limit the energy demands of mosques without violating the worshippers’ thermal comfort. Most of these researches dealt with enhancing the mosque envelope through the addition of insulation layers. Since most mosque walls in Qatar are mostly already insulated, this study proposes the installation of shading on the mosque roof that is anticipated to yield similar energy savings in comparison with insulated roofs. An actual mosque in Qatar, which is a combination of six different spaces consisting of men and women’s prayer rooms, ablutions and toilets, was simulated and yielded a total annual energy demand of 619.55 kWh/m2. The mosque, whose walls are already insulated, yielded 9.1% energy savings when an insulation layer was added to its roof whereas it produced 6.2% energy savings when a shading layer was added above this roof. As the reconstruction of the roof envelope is practically unrealistic in existing mosques, the addition of shading to the roof was found to produce comparable energy savings. Lastly, it was found that new mosques with thin-roof insulation and shading tend to be more energy-efficient than those with thick-roof insulation.

Credit PSR. This interior view of the building equipment room ...

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

Credit PSR. This interior view of the building equipment room displays heat exchangers and fan units with insulated piping for hot and cold water at left. Environmental controls and fire fighting system controls appear at right - Jet Propulsion Laboratory Edwards Facility, Propellant Curing Building, Edwards Air Force Base, Boron, Kern County, CA

Thermal Response Of Composite Insulation

NASA Technical Reports Server (NTRS)

Stewart, David A.; Leiser, Daniel B.; Smith, Marnell; Kolodziej, Paul

1988-01-01

Engineering model gives useful predictions. Pair of reports presents theoretical and experimental analyses of thermal responses of multiple-component, lightweight, porous, ceramic insulators. Particular materials examined destined for use in Space Shuttle thermal protection system, test methods and heat-transfer theory useful to chemical, metallurgical, and ceramic engineers needing to calculate transient thermal responses of refractory composites.

16 CFR 460.5 - R-value tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... INSULATION 460.5 R-value tests. R-value measures resistance to heat flow. R-values given in labels, fact...) All types of insulation except aluminum foil must be tested with ASTM C 177-04, “Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded...

16 CFR 460.5 - R-value tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... INSULATION 460.5 R-value tests. R-value measures resistance to heat flow. R-values given in labels, fact...) All types of insulation except aluminum foil must be tested with ASTM C 177-04, “Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded...

16 CFR 460.5 - R-value tests.

Code of Federal Regulations, 2012 CFR

2012-01-01

... INSULATION 460.5 R-value tests. R-value measures resistance to heat flow. R-values given in labels, fact...) All types of insulation except aluminum foil must be tested with ASTM C 177-04, “Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded...

16 CFR 460.5 - R-value tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... INSULATION 460.5 R-value tests. R-value measures resistance to heat flow. R-values given in labels, fact...) All types of insulation except aluminum foil must be tested with ASTM C 177-04, “Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded...

16 CFR 460.5 - R-value tests.

Code of Federal Regulations, 2014 CFR

2014-01-01

... INSULATION 460.5 R-value tests. R-value measures resistance to heat flow. R-values given in labels, fact...) All types of insulation except aluminum foil must be tested with ASTM C 177-04, “Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded...

Development of chemical compositions for impervious screens in rocks

NASA Astrophysics Data System (ADS)

Kurlenya, MV; Serdyukov, SV; Shilova, TV; Patutin, AV

2017-02-01

The paper presents the method to create anti-seepage screens by hydraulic fracturing with three-component polyurethane mixture. The proposed working fluids and their pumping circuits allow creation of a fracture and an adjacent insulation layer. Gas permeability of porous medium is determined at limit consumption of reagents per insulating screen unit area.

Final Report: Research Study on Development of Environmental Friendly Spray-on Foam Insulation (SOFI) for the External Tank (ET)

NASA Technical Reports Server (NTRS)

Stuckey, James M.

1996-01-01

The selection and quantification of four foams using a more environmentally friendly HCFC-141b blowing agent replacing foams that used the CFC-11 blowing agent for the external tank (ET) LWT has been addressed along with problems and solutions that were encountered during verification. The effort on two lower density spray foams for the ET SLWT are presented, but predicted weight savings were not encouraging. Suggestions for possible problem solving are included along with a new approach for selecting foams for qualification as back-up foams for the foams used on the ET LWT. We investigated three resins for use as thermally sprayed coatings for corrosion prevention on metal. The best coating was obtained with a thermoplastic polyimide resin. This coating has a good chance of meeting ET requirements. Possible third generation blowing agents have been shown usable in polyurethane spray and pour foams, and solubility in isocyannate foam components are acceptable. We considered aerogels as insulation materials on space vehicles, and suggested a liner for a liquid oxygen (LOX) composite tank.

A method to restrain the charging effect on an insulating substrate in high energy electron beam lithography

NASA Astrophysics Data System (ADS)

Mingyan, Yu; Shirui, Zhao; Yupeng, Jing; Yunbo, Shi; Baoqin, Chen

2014-12-01

Pattern distortions caused by the charging effect should be reduced while using the electron beam lithography process on an insulating substrate. We have developed a novel process by using the SX AR-PC 5000/90.1 solution as a spin-coated conductive layer, to help to fabricate nanoscale patterns of poly-methyl-methacrylate polymer resist on glass for phased array device application. This method can restrain the influence of the charging effect on the insulating substrate effectively. Experimental results show that the novel process can solve the problems of the distortion of resist patterns and electron beam main field stitching error, thus ensuring the accuracy of the stitching and overlay of the electron beam lithography system. The main characteristic of the novel process is that it is compatible to the multi-layer semiconductor process inside a clean room, and is a green process, quite simple, fast, and low cost. It can also provide a broad scope in the device development on insulating the substrate, such as high density biochips, flexible electronics and liquid crystal display screens.

A Design Method for Topologically Insulating Metamaterials

NASA Astrophysics Data System (ADS)

Matlack, Kathryn; Serra-Garcia, Marc; Palermo, Antonio; Huber, Sebastian; Daraio, Chiara

Topological insulators are a unique class of electronic materials that exhibit protected edge states that are insulating in the bulk, and immune to back-scattering and defects. Discrete models, such as mass-spring systems, provide a means to translate these properties, based on the quantum hall spin effect, to the mechanical domain. This talk will present how to engineer a 2D mechanical metamaterial that supports topologically-protected and defect-immune edge states, directly from the mass-spring model of a topological insulator. The design method uses combinatorial searches plus gradient-based optimizations to determine the configuration of the metamaterials building blocks that leads to the global behavior specified by the target mass-spring model. We use metamaterials with weakly coupled unit cells to isolate the dynamics within our frequency range of interest and to enable a systematic design process. This approach can generally be applied to implement behaviors of a discrete model directly in mechanical, acoustic, or photonic metamaterials within the weak-coupling regime. This work was partially supported by the ETH Postdoctoral Fellowship, and by the Swiss National Science Foundation.

Micro-architecture embedding ultra-thin interlayer to bond diamond and silicon via direct fusion

NASA Astrophysics Data System (ADS)

Kim, Jong Cheol; Kim, Jongsik; Xin, Yan; Lee, Jinhyung; Kim, Young-Gyun; Subhash, Ghatu; Singh, Rajiv K.; Arjunan, Arul C.; Lee, Haigun

2018-05-01

The continuous demand on miniaturized electronic circuits bearing high power density illuminates the need to modify the silicon-on-insulator-based chip architecture. This is because of the low thermal conductivity of the few hundred nanometer-thick insulator present between the silicon substrate and active layers. The thick insulator is notorious for releasing the heat generated from the active layers during the operation of devices, leading to degradation in their performance and thus reducing their lifetime. To avoid the heat accumulation, we propose a method to fabricate the silicon-on-diamond (SOD) microstructure featured by an exceptionally thin silicon oxycarbide interlayer (˜3 nm). While exploiting the diamond as an insulator, we employ spark plasma sintering to render the silicon directly fused to the diamond. Notably, this process can manufacture the SOD microarchitecture via a simple/rapid way and incorporates the ultra-thin interlayer for minute thermal resistance. The method invented herein expects to minimize the thermal interfacial resistance of the devices and is thus deemed as a breakthrough appealing to the current chip industry.

HAREM: high aspect ratio etching and metallization for microsystems fabrication

NASA Astrophysics Data System (ADS)

Sarajlic, Edin; Yamahata, Christophe; Cordero, Mauricio; Collard, Dominique; Fujita, Hiroyuki

2008-07-01

We report a simple bulk micromachining method for the fabrication of high aspect ratio monocrystalline silicon MEMS (microelectromechanical systems) in a standard silicon wafer. We call this two-mask microfabrication process high aspect ratio etching and metallization or HAREM: it combines double-side etching and metallization to create suspended micromechanical structures with electrically 'insulating walls' on their backside. The insulating walls ensure a proper electrical insulation between the different actuation and sensing elements situated on either fixed or movable parts of the device. To demonstrate the high potential of this simple microfabrication method, we have designed and characterized electrostatically actuated microtweezers that integrate a differential capacitive sensor. The prototype showed an electrical insulation better than 1 GΩ between the different elements of the device. Furthermore, using a lock-in amplifier circuit, we could measure the position of the moving probe with few nanometers resolution for a displacement range of about 3 µm. This work was presented in part at the 21st IEEE MEMS Conference (Tucson, AZ, USA, 13-17 January, 2008) (doi:10.1109/MEMSYS.2008.4443656).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shao, Tao, E-mail: st@mail.iee.ac.cn; Yang, Wenjin; Zhang, Cheng

Polymer materials, such as polymethylmethacrylate (PMMA), are widely used as insulators in vacuum. The insulating performance of a high-voltage vacuum system is mainly limited by surface flashover of the insulators rather than bulk breakdown. Non-thermal plasmas are an efficient method to modify the chemical and physical properties of polymer material surfaces, and enhance the surface insulating performance. In this letter, an atmospheric-pressure dielectric barrier discharge is used to treat the PMMA surface to improve the surface flashover strength in vacuum. Experimental results indicate that the plasma treatment method using Ar and CF{sub 4} (10:1) as the working gas can etchmore » the PMMA surface, introduce fluoride groups to the surface, and then alter the surface characteristics of the PMMA. The increase in the surface roughness can introduce physical traps that can capture free electrons, and the fluorination can enhance the charge capturing ability. The increase in the surface roughness and the introduction of the fluoride groups can enhance the PMMA hydrophobic ability, improve the charge capturing ability, decrease the secondary electron emission yield, increase the surface resistance, and improve the surface flashover voltage in vacuum.« less

Thermal conductivity and combustion properties of wheat gluten foams.

PubMed

Blomfeldt, Thomas O J; Nilsson, Fritjof; Holgate, Tim; Xu, Jianxiao; Johansson, Eva; Hedenqvist, Mikael S

2012-03-01

Freeze-dried wheat gluten foams were evaluated with respect to their thermal and fire-retardant properties, which are important for insulation applications. The thermal properties were assessed by differential scanning calorimetry, the laser flash method and a hot plate method. The unplasticised foam showed a similar specific heat capacity, a lower thermal diffusivity and a slightly higher thermal conductivity than conventional rigid polystyrene and polyurethane insulation foams. Interestingly, the thermal conductivity was similar to that of closed cell polyethylene and glass-wool insulation materials. Cone calorimetry showed that, compared to a polyurethane foam, both unplasticised and glycerol-plasticised foams had a significantly longer time to ignition, a lower effective heat of combustion and a higher char content. Overall, the unplasticised foam showed better fire-proof properties than the plasticized foam. The UL 94 test revealed that the unplasticised foam did not drip (form droplets of low viscous material) and, although the burning times varied, self-extinguished after flame removal. To conclude both the insulation and fire-retardant properties were very promising for the wheat gluten foam. © 2012 American Chemical Society

Nanoscale thermal imaging of VO2 via Poole-Frenkel conduction

NASA Astrophysics Data System (ADS)

Spitzig, Alyson; Hoffman, Jason D.; Pivonka, Adam E.; Mickalide, Harry; Frenzel, Alex; Kim, Jeehoon; Ko, Changhyun; Zhou, You; O'Connor, Kevin; Hudson, Eric W.; Ramanathan, Shriram; Hoffman, Jennifer E.

We present a novel method for nanoscale thermal imaging of insulating thin films. We demonstrate this method on VO2, which undergoes a sharp insulator-to-metal transition at 340 K. We sweep the voltage applied to a conducting atomic force microscope tip in contact mode at room temperature and measure the resultant current through a VO2 film. The Poole-Frenkel (PF) conduction mechanism, which dominates in the insulating state of VO2, is fit to extract the local temperature of the film using fundamental constants and known film properties. We measure the local electric field and temperature immediately preceding the insulator-to-metal transition in VO2 to determine whether the transition can be triggered by an applied electric field alone. We calculate an average temperature of 334 +/- 5 K, implying that Joule heating has locally warmed the sample very close to the transition temperature. Our thermometry technique opens up the possibility to measure the local temperature of any film dominated by the PF conduction mechanism, and presents the opportunity to extend our technique to other conduction mechanisms. Canada Excellence Research Chair program and NSERC - CGSM.

Cryogenic insulation standard data and methodologies

NASA Astrophysics Data System (ADS)

Demko, J. A.; Fesmire, J. E.; Johnson, W. L.; Swanger, A. M.

2014-01-01

Although some standards exist for thermal insulation, few address the sub-ambient temperature range and cold-side temperatures below 100 K. Standards for cryogenic insulation systems require cryostat testing and data analysis that will allow the development of the tools needed by design engineers and thermal analysts for the design of practical cryogenic systems. Thus, this critically important information can provide reliable data and methodologies for industrial efficiency and energy conservation. Two Task Groups have been established in the area of cryogenic insulation systems Under ASTM International's Committee C16 on Thermal Insulation. These are WK29609 - New Standard for Thermal Performance Testing of Cryogenic Insulation Systems and WK29608 - Standard Practice for Multilayer Insulation in Cryogenic Service. The Cryogenics Test Laboratory of NASA Kennedy Space Center and the Thermal Energy Laboratory of LeTourneau University are conducting Inter-Laboratory Study (ILS) of selected insulation materials. Each lab carries out the measurements of thermal properties of these materials using identical flat-plate boil-off calorimeter instruments. Parallel testing will provide the comparisons necessary to validate the measurements and methodologies. Here we discuss test methods, some initial data in relation to the experimental approach, and the manner reporting the thermal performance data. This initial study of insulation materials for sub-ambient temperature applications is aimed at paving the way for further ILS comparative efforts that will produce standard data sets for several commercial materials. Discrepancies found between measurements will be used to improve the testing and data reduction techniques being developed as part of the future ASTM International standards.

Suppression of surface charge accumulation on Al{sub 2}O{sub 3}-filled epoxy resin insulator under dc voltage by direct fluorination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Boya; Zhang, Guixin, E-mail: guixin@mail.tsinghua.edu.cn; Li, Chuanyang

2015-12-15

Surface charge accumulation on insulators under high dc voltage is a major factor that may lead to the reduction of insulation levels in gas insulated devices. In this paper, disc insulators made of Al{sub 2}O{sub 3}-filled epoxy resin were surface fluorinated using a F{sub 2}/N{sub 2} mixture (12.5% F{sub 2}) at 50 °C and 0.1 MPa for different durations of 15 min, 30 min and 60 min. A dc voltage was applied to the insulator for 30 min and the charge density on its surface was measured by an electrostatic probe. The results revealed significant lower surface charge densities on themore » fluorinated insulators in comparison with the original one. Surface conductivity measurements indicated a higher surface conductivity by over three orders of magnitude after fluorination, which would allow the charges to transfer along the surface and thus may suppress their accumulation. Further, attenuated total reflection infrared analysis and surface morphology observations of the samples revealed that the introduction of fluoride groups altered the surface physicochemical properties. These structure changes, especially the physical defects reduced the depth of charge traps in the surface layer, which was verified by the measurement of energy distributions of the electron and hole traps based on the isothermal current theory. The results in this paper demonstrate that fluorination can be a promising and effective method to suppress surface charge accumulation on epoxy insulators in gas insulated devices.« less

Simultaneous Noncontact Precision Imaging of Microstructural and Thickness Variation in Dielectric Materials Using Terahertz Energy

NASA Technical Reports Server (NTRS)

Roth, Don J.; Seebo, Jeffrey P.; Winfree, William P.

2008-01-01

This article describes a noncontact single-sided terahertz electromagnetic measurement and imaging method that simultaneously characterizes microstructural (egs. spatially-lateral density) and thickness variation in dielectric (insulating) materials. The method was demonstrated for two materials-Space Shuttle External Tank sprayed-on foam insulation and a silicon nitride ceramic. It is believed that this method can be used as an inspection method for current and future NASA thermal protection system and other dielectric material inspection applications, where microstructural and thickness variation require precision mapping. Scale-up to more complex shapes such as cylindrical structures and structures with beveled regions would appear to be feasible.

Method of determining operation parameters of stand tests of vehicle suspension elements under conditions of ultra-low temperatures

NASA Astrophysics Data System (ADS)

Fedyanov, E. A.; Sokolov-Dobrev, N. S.; Ljashenko, M. V.; Shekhovtsov, V. V.; Potapov, P. V.; Dolotov, A. A.; Klementiev, E. V.

2018-05-01

This article presents the description of the method for estimation of heat flows characteristic during research of operability of suspension elements under the conditions of ultralow temperature. The mentioned research is performed at the test bench created in VSTU. Solid carbon dioxide (also known as artificial ice) is used as the coolant. The method provides evaluation of required quantity of artificial ice and cooling dynamics of the test unit in the insulated low-temperature chamber with structurally specified parameters of heat insulation. Also the method allows computation of heat intake into the chamber volume.

Ceramic membrane development in NGK

NASA Astrophysics Data System (ADS)

Araki, Kiyoshi; Sakai, Hitoshi

2011-05-01

NGK Insulators, Ltd. was established in 1919 to manufacture the electric porcelain insulators for power transmission lines. Since then, our business has grown as one of the world-leading ceramics manufacturing companies and currently supply with the various environmentally-benign ceramic products to worldwide. In this paper, ceramic membrane development in NGK is described in detail. We have been selling ceramic microfiltration (MF) membranes and ultra-filtration (UF) membranes for many years to be used for solid/liquid separation in various fields such as pharmaceutical, chemical, food and semiconductor industries. In Corporate R&D, new ceramic membranes with sub-nanometer sized pores, which are fabricated on top of the membrane filters as support, are under development for gas and liquid/liquid separation processes.

Workshop on multifactor aging mechanisms and models

NASA Astrophysics Data System (ADS)

Agarwal, V. K.

1992-10-01

There have been considerable efforts to understand the aging and failure mechanisms of insulation in electrical systems. However, progress has been slow because of the complex nature of the subject particularly when dealing with multiple stresses e.g. electrical, thermal, mechanical, radiation, humidity and other environmental factors. When an insulating material is exposed to just one stress factor e.g. electric field, one must devise test(s) which are not only economically efficient and practical but which take into account the nature of electric field (ac, dc and pulsed), duration and level or field strength, and field configurations. Any additional stress factor(s) make the matrix of measurements and the understanding of resulting degradation processes more complex, time consuming and expensive.

Insulator-based DEP with impedance measurements for analyte detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davalos, Rafael V.; Simmons, Blake A.; Crocker, Robert W.

2010-03-16

Disclosed herein are microfluidic devices for assaying at least one analyte specie in a sample comprising at least one analyte concentration area in a microchannel having insulating structures on or in at least one wall of the microchannel which provide a nonuniform electric field in the presence of an electric field provided by off-chip electrodes; and a pair of passivated sensing electrodes for impedance detection in a detection area. Also disclosed are assay methods and methods of making.

EFFECTS OF LASER RADIATION ON MATTER: Distribution function of microinclusions in polymethylmethacrylate and its evolution under the influence of a series of laser pulses

NASA Astrophysics Data System (ADS)

Glauberman, G. Ya; Savanin, S. Yu; Shkunov, V. V.; Shumov, D. E.

1990-08-01

A new method is proposed for the derivation of the distribution function of the experimentally determined breakdown thresholds of absorbing microinclusions in a transparent insulator. Expressions are obtained for describing the evolution of this function in the course of irradiation of the insulator with laser pulses of constant energy density. The method is applied to calculate the distribution function of microinclusions in polymethylmethacrylate and the evolution of this function.

Microwave and Millimeter Wave Nondestructive Evaluation of the Space Shuttle External Tank Insulating Foam

NASA Technical Reports Server (NTRS)

Shrestha, S.; Kharkovsky, S.; Zoughi, R.; Hepburn, F

2005-01-01

The Space Shuttle Columbia s catastrophic failure has been attributed to a piece of external fuel tank insulating SOFI (Spray On Foam Insulation) foam striking the leading edge of the left wing of the orbiter causing significant damage to some of the protecting heat tiles. The accident emphasizes the growing need to develop effective, robust and life-cycle oriented methods of nondestructive testing and evaluation (NDT&E) of complex conductor-backed insulating foam and protective acreage heat tiles used in the space shuttle fleet and in future multi-launch space vehicles. The insulating SOFI foam is constructed from closed-cell foam. In the microwave regime this foam is in the family of low permittivity and low loss dielectric materials. Near-field microwave and millimeter wave NDT methods were one of the techniques chosen for this purpose. To this end several flat and thick SOFI foam panels, two structurally complex panels similar to the external fuel tank and a "blind" panel were used in this investigation. Several anomalies such as voids and disbonds were embedded in these panels at various locations. The location and properties of the embedded anomalies in the "blind" panel were not disclosed to the investigating team prior to the investigation. Three frequency bands were used in this investigation covering a frequency range of 8-75 GHz. Moreover, the influence of signal polarization was also investigated. Overall the results of this investigation were very promising for detecting the presence of anomalies in different panels covered with relatively thick insulating SOFI foam. Different types of anomalies were detected in foam up to 9 in thick. Many of the anomalies in the more complex panels were also detected. When investigating the blind panel no false positives were detected. Anomalies in between and underneath bolt heads were not easily detected. This paper presents the results of this investigation along with a discussion of the capabilities of the method used.

Behavior of Insulated Carbon-FRP-Strengthened RC Beams Exposed to Fire

NASA Astrophysics Data System (ADS)

Sayin, B.

2014-09-01

There are two main approaches to improving the fire resistance of fiber-reinforced polymer (FRP) systems. While the most common method is to protect or insulate the FRP system, an other way is to use fibers and resins with a better fire performance. This paper presents a numerical investigation into the five protection behavior of insulated carbon-fiber-reinforced-polymer (CFRP)-strengthened reinforced concrete (RC) beams. The effects of external loading and thermal expansion of materials at elevated temperatures are taken into consideration in a finite-element model. The validity of the numerical model is demonstrated with results from an existing experimental study on insulated CFRP-strengthened RC beams. Conclusions of this investigation are employed to predict the structural behavior of CFRP-strengthened concrete structures.

Conformally encapsulated multi-electrode arrays with seamless insulation

DOEpatents

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.

Dielectric response of Anderson and pseudogapped insulators

NASA Astrophysics Data System (ADS)

Feigel’man, M. V.; Ivanov, D. A.; Cuevas, E.

2018-05-01

Using a combination of analytic and numerical methods, we study the polarizability of a (non-interacting) Anderson insulator in one-, two-, and three-dimensions and demonstrate that, in a wide range of parameters, it scales proportionally to the square of the localization length, contrary to earlier claims based on the effective-medium approximation. We further analyze the effect of electron–electron interactions on the dielectric constant in quasi-1D, quasi-2D and 3D materials with large localization length, including both Coulomb repulsion and phonon-mediated attraction. The phonon-mediated attraction (in the pseudogapped state on the insulating side of the superconductor-insulator transition) produces a correction to the dielectric constant, which may be detected from a linear response of a dielectric constant to an external magnetic field.

Interior thermal insulation systems for historical building envelopes

NASA Astrophysics Data System (ADS)

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.

Short-Term Environmental Effects and Their Influence on Spatial Homogeneity of Organic Solar Cell Functionality.

PubMed

Chien, Huei-Ting; Zach, Peter W; Friedel, Bettina

2017-08-23

In this study, we focus on the induced degradation and spatial inhomogeneity of organic photovoltaic devices under different environmental conditions, uncoupled from the influence of any auxiliary hole-transport (HT) layer. During testing of the corresponding devices comprising the standard photoactive layer of poly(3-hexylthiophene) as donor, blended with phenyl-C 61 -butyric acid methyl ester as acceptor, a comparison was made between the nonencapsulated devices upon exposure to argon in the dark, dry air in the dark, dry air with illumination, and humid air in the dark. The impact on the active layer's photophysics is discussed, along with the device physics in terms of integral solar cell performance and spatially resolved photocurrent distribution with point-to-point analysis of the diode characteristics to determine the origin of the observed integrated organic photovoltaic device behavior. The results show that even without the widely used hygroscopic HT layer, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), humidity is still a major factor in the short-term environmental degradation of organic solar cells with this architecture, and not only oxygen or light, as is often reported. Different from previous reports where water-induced device degradation was spatially homogeneous and formation of Al 2 O 3 islands was only seen for oxygen permeation through pinholes in aluminum, we observed insulating islands merely after humidity exposure in the present study. Further, we demonstrated with laser beam induced current mapping and point-to-point diode analysis that the water-induced performance losses are a result of the exposed device area comprising regions with entirely unaltered high output and intact diode behavior and those with severe degradation showing detrimentally lowered output and voltage-independent charge blocking, which is essentially insulating behavior. It is suggested that this is caused by transport of water through pinholes to the organic/metal interface, where they form insulating oxide or hydroxide islands, while the organic active layer stays unharmed.

Hybrid particle traps and conditioning procedure for gas insulated transmission lines

DOEpatents

Dale, Steinar J.; Cookson, Alan H.

1982-01-01

A gas insulated transmission line includes an outer sheath, an inner condor within the outer sheath, insulating supports supporting the inner conductor within the outer sheath, and an insulating gas electrically insulating the inner conductor from the outer sheath. An apertured particle trapping ring is disposed within the outer sheath, and the trapping ring has a pair of dielectric members secured at each longitudinal end thereof, with the dielectric members extending outwardly from the trapping ring along an arc. A support sheet having an adhesive coating thereon is secured to the trapping ring and disposed on the outer sheath within the low field region formed between the trapping ring and the outer sheath. A conditioning method used to condition the transmission line prior to activation in service comprises applying an AC voltage to the inner conductor in a plurality of voltage-time steps, with the voltage-time steps increasing in voltage magnitude while decreasing in time duration.

Lifetime assessment by intermittent inspection under the mixture Weibull power law model with application to XLPE cables.

PubMed

Hirose, H

1997-01-01

This paper proposes a new treatment for electrical insulation degradation. Some types of insulation which have been used under various circumstances are considered to degrade at various rates in accordance with their stress circumstances. The cross-linked polyethylene (XLPE) insulated cables inspected by major Japanese electric companies clearly indicate such phenomena. By assuming that the inspected specimen is sampled from one of the clustered groups, a mixed degradation model can be constructed. Since the degradation of the insulation under common circumstances is considered to follow a Weibull distribution, a mixture model and a Weibull power law can be combined. This is called The mixture Weibull power law model. By using the maximum likelihood estimation for the newly proposed model to Japanese 22 and 33 kV insulation class cables, they are clustered into a certain number of groups by using the AIC and the generalized likelihood ratio test method. The reliability of the cables at specified years are assessed.

Unsteady Stored Heat Behavior in Building Frame of Reinforced Concrete Structure Type Cold Storage

NASA Astrophysics Data System (ADS)

Nomura, Tomohiro; Murakami, Yuji; Uchikawa, Motoyuki

The time variation of temperature in the reinforced concrete frame with an internal insulation or with an external insulation and the unsteady stored heat behavior, which results from the thermal mass of the concrete frame, have been investigated. The experiments with the concrete models and the measurements of the heat flux through the practical cold storage were performed. The experimental results under the unsteady condition showed great difference of the stored heat behavior between the internal insulation type and the external type. In addition, it was shown that the external insulation frame was useful for heat storage. The simulation method with two dimentional unsteady FEM was introduced for easily analyzing the stored heat behavior problems of the practical cold storages, which had various specifications in design. The calculated results of the heat flux and temperature in the concrete frame agreed with the experiments approximately. From these results, the suggestions for the design of the insulation wall under the unsteady condition were given.

Ripple-modulated electronic structure of a 3D topological insulator.

PubMed

Okada, Yoshinori; Zhou, Wenwen; Walkup, D; Dhital, Chetan; Wilson, Stephen D; Madhavan, V

2012-01-01

Three-dimensional topological insulators host linearly dispersing states with unique properties and a strong potential for applications. An important ingredient in realizing some of the more exotic states in topological insulators is the ability to manipulate local electronic properties. Direct analogy to the Dirac material graphene suggests that a possible avenue for controlling local properties is via a controlled structural deformation such as the formation of ripples. However, the influence of such ripples on topological insulators is yet to be explored. Here we use scanning tunnelling microscopy to determine the effects of one-dimensional buckling on the electronic properties of Bi(2)Te(3.) By tracking spatial variations of the interference patterns generated by the Dirac electrons we show that buckling imposes a periodic potential, which locally modulates the surface-state dispersion. This suggests that forming one- and two-dimensional ripples is a viable method for creating nanoscale potential landscapes that can be used to control the properties of Dirac electrons in topological insulators.

Stratification of TAD boundaries reveals preferential insulation of super-enhancers by strong boundaries.

PubMed

Gong, Yixiao; Lazaris, Charalampos; Sakellaropoulos, Theodore; Lozano, Aurelie; Kambadur, Prabhanjan; Ntziachristos, Panagiotis; Aifantis, Iannis; Tsirigos, Aristotelis

2018-02-07

The metazoan genome is compartmentalized in areas of highly interacting chromatin known as topologically associating domains (TADs). TADs are demarcated by boundaries mostly conserved across cell types and even across species. However, a genome-wide characterization of TAD boundary strength in mammals is still lacking. In this study, we first use fused two-dimensional lasso as a machine learning method to improve Hi-C contact matrix reproducibility, and, subsequently, we categorize TAD boundaries based on their insulation score. We demonstrate that higher TAD boundary insulation scores are associated with elevated CTCF levels and that they may differ across cell types. Intriguingly, we observe that super-enhancers are preferentially insulated by strong boundaries. Furthermore, we demonstrate that strong TAD boundaries and super-enhancer elements are frequently co-duplicated in cancer patients. Taken together, our findings suggest that super-enhancers insulated by strong TAD boundaries may be exploited, as a functional unit, by cancer cells to promote oncogenesis.

Excavationless Exterior Foundation Insulation Field Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schirber, T.; Mosiman, G.; Ojczyk, C.

Building science research supports installing exterior (soil side) foundation insulation as the optimal method to enhance the hygrothermal performance of new homes. With exterior foundation insulation, water management strategies are maximized while insulating the basement space and ensuring a more even temperature at the foundation wall. However, such an approach can be very costly and disruptive when applied to an existing home, requiring deep excavation around the entire house. The NorthernSTAR Building America Partnership team implemented an innovative, minimally invasive foundation insulation upgrade technique on an existing home. The approach consisted of using hydrovac excavation technology combined with a liquidmore » insulating foam. The team was able to excavate a continuous 4" wide by 4' to 5' deep trench around the entire house, 128 linear feet, except for one small part under the stoop that was obstructed with concrete debris. The combination pressure washer and vacuum extraction technology also enabled the elimination of large trenches and soil stockpiles normally produced by backhoe excavation. The resulting trench was filled with liquid insulating foam, which also served as a water-control layer of the assembly. The insulation was brought above grade using a liquid foam/rigid foam hybrid system and terminated at the top of the rim joist. Cost savings over the traditional excavation process ranged from 23% to 50%. The excavationless process could result in even greater savings since replacement of building structures, exterior features, utility meters, and landscaping would be minimal or non-existent in an excavationless process.« less

New portable pipe wall thickness measuring technique

NASA Astrophysics Data System (ADS)

Pascente, Joseph E.

1998-03-01

One of the biggest inspection challenges facing many of the process industries; namely the petrochemical, refining, fossil power, and pulp and paper industries is: How to effectively examine their insulated piping? While there are a number of failure mechanisms involved in various process piping systems, piping degradation through corrosion and erosion are by far the most prevalent. This degradation can be in the form of external corrosion under insulation, internal corrosion through a variety of mechanisms, and internal erosion caused by the flow of the product through the pipe. Refineries, chemical plants and electrical power plants have MANY thousands of miles of pipe that are insulated to prevent heat loss or heat absorption. This insulation is often made up of several materials, with calcium based material being the most dense. The insulating material is usually wrapped with an aluminum or stainless steel outer wrap. Verification of wall thickness of these pipes can be accomplished by removing the insulation and doing an ultrasound inspection or by taking x- rays at a tangent to the edge of the pipe through the insulation. Both of these processes are slow and expensive. The time required to obtain data is measured in hours per meter. The ultrasound method requires that the insulation be plugged after the inspection. The surface needs to be cleaned or the resulting data will not be accurate. The tangent x-ray only shows two thicknesses and requires that the area be roped off because of radiation safety.

Spin injection and spin transport in paramagnetic insulators

DOE PAGES

Okamoto, Satoshi

2016-02-22

We investigate the spin injection and the spin transport in paramagnetic insulators described by simple Heisenberg interactions using auxiliary particle methods. Some of these methods allow access to both paramagnetic states above magnetic transition temperatures and magnetic states at low temperatures. It is predicted that the spin injection at an interface with a normal metal is rather insensitive to temperatures above the magnetic transition temperature. On the other hand below the transition temperature, it decreases monotonically and disappears at zero temperature. We also analyze the bulk spin conductance. We show that the conductance becomes zero at zero temperature as predictedmore » by linear spin wave theory but increases with temperature and is maximized around the magnetic transition temperature. These findings suggest that the compromise between the two effects determines the optimal temperature for spintronics applications utilizing magnetic insulators.« less

Method and tool for expanding tubular members by electro-hydraulic forming

DOEpatents

Golovashchenko, Sergey Fedorovich; Bonnen, John Joseph Francis

2013-10-29

An electro-hydraulic forming tool having one or more electrodes for forming parts with sharp corners. The electrodes may be moved and sequentially discharged several times to form various areas of the tube. Alternatively, a plurality of electrodes may be provided that are provided within an insulating tube that defines a charge area opening. The insulating tube is moved to locate the charge area opening adjacent one of the electrodes to form spaced locations on a preform. In other embodiments, a filament wire is provided in a cartridge or supported by an insulative support.

Microstructural Investigation of High Emittance Glass Coatings on Fibrous Ceramic Insulation

NASA Technical Reports Server (NTRS)

Ellerby, Don; Leiser, Dan; DiFiore, Robert; Figone, Jeff; Smith, Dane; Loehman, Ron; Kotula, Paul

2001-01-01

This viewgraph presentation provides an overview of the Space Shuttle Thermal Protection System (TPS) and the various products incorporated in the TPS. There are three tile systems which include pure silica, fibrous refractory composite insulation (FRCI), and alumina enhanced thermal barrier (AETB). Coating systems include reaction cured glass (RCG) and toughened uni-piece insulation (TUFI). The microstructures of these systems are explored as are the manufacturing processes associated with each. Microstructural investigation using methods such as automated X-ray spectral image analysis (AXSIA) is a crucial part of understanding the mechanical nature of these systems.

Cryogenic Vacuum Insulation for Vessels and Piping

NASA Technical Reports Server (NTRS)

Kogan, A.; Fesmire, J.; Johnson, W.; Minnick, J.

2010-01-01

Cryogenic vacuum insulation systems, with proper materials selection and execution, can offer the highest levels of thermal performance. Three areas of consideration are vital to achieve the optimum result: materials, representative test conditions, and engineering approach for the particular application. Deficiency in one of these three areas can prevent optimum performance and lead to severe inefficiency. Materials of interest include micro-fiberglass, multilayer insulation, and composite arrangements. Cylindrical liquid nitrogen boil-off calorimetry methods were used. The need for standard thermal conductivity data is addressed through baseline testing. Engineering analysis and design factors such as layer thickness, density, and practicality are also considered.

Pinpoint and bulk electrochemical reduction of insulating silicon dioxide to silicon.

PubMed

Nohira, Toshiyuki; Yasuda, Kouji; Ito, Yasuhiko

2003-06-01

Silicon dioxide (SiO(2)) is conventionally reduced to silicon by carbothermal reduction, in which the oxygen is removed by a heterogeneous-homogeneous reaction sequence at approximately 1,700 degrees C. Here we report pinpoint and bulk electrochemical methods for removing oxygen from solid SiO(2) in a molten CaCl(2) electrolyte at 850 degrees C. This approach involves a 'contacting electrode', in which a metal wire supplies electrons to a selected region of the insulating SiO(2). Bulk reduction of SiO(2) is possible by increasing the number of contacting points. The same method was also demonstrated with molten LiCl-KCl-CaCl(2) at 500 degrees C. The novelty and relative simplicity of this method might lead to new processes in silicon semiconductor technology, as well as in high-purity silicon production. The methodology may be applicable to electrochemical processing of a wide variety of insulating materials, provided that the electrolyte dissolves the appropriate constituent ion(s) of the material.

Instrumentation for Studies of Electron Emission and Charging From Insulators

NASA Technical Reports Server (NTRS)

Thomson, C. D.; Zavyalov, V.; Dennison, J. R.

2004-01-01

Making measurements of electron emission properties of insulators is difficult since insulators can charge either negatively or positively under charge particle bombardment. In addition, high incident energies or high fluences can result in modification of a material s conductivity, bulk and surface charge profile, structural makeup through bond breaking and defect creation, and emission properties. We discuss here some of the charging difficulties associated with making insulator-yield measurements and review the methods used in previous studies of electron emission from insulators. We present work undertaken by our group to make consistent and accurate measurements of the electron/ion yield properties for numerous thin-film and thick insulator materials using innovative instrumentation and techniques. We also summarize some of the necessary instrumentation developed for this purpose including fast response, low-noise, high-sensitivity ammeters; signal isolation and interface to standard computer data acquisition apparatus using opto-isolation, sample-and-hold, and boxcar integration techniques; computer control, automation and timing using Labview software; a multiple sample carousel; a pulsed, compact, low-energy, charge neutralization electron flood gun; and pulsed visible and UV light neutralization sources. This work is supported through funding from the NASA Space Environments and Effects Program and the NASA Graduate Research Fellowship Program.

Development of a Moisture-in-Solid-Insulation Sensor for Power Transformers

PubMed Central

García, Belén; García, Diego; Robles, Guillermo

2015-01-01

Moisture is an important variable that must be kept under control to guarantee a safe operation of power transformers. Because of the hydrophilic character of cellulose, water mainly remains in the solid insulation, while just a few parts per million are dissolved in oil. The distribution of moisture between paper and oil is not static, but varies depending on the insulation temperature, and thus, water migration processes take place continuously during transformers operation. In this work, a sensor is presented that allows the determination of the moisture content of the transformer solid insulation in the steady state and during the moisture migration processes. The main objective of the design is that the electrodes of the sensor should not obstruct the movement of water from the solid insulation to the oil, so the proposed prototype uses a metallic-mesh electrode to do the measurements. The measurement setup is based on the characterization of the insulation dielectric response by means of the frequency dielectric spectroscopy (FDS) method. The sensitivity of the proposed sensor has been tested on samples with a moisture content within 1% to 5%, demonstrating the good sensitivity and repeatability of the measurements. PMID:25658393

Development of a moisture-in-solid-insulation sensor for power transformers.

PubMed

García, Belén; García, Diego; Robles, Guillermo

2015-02-04

Moisture is an important variable that must be kept under control to guarantee a safe operation of power transformers. Because of the hydrophilic character of cellulose, water mainly remains in the solid insulation, while just a few parts per million are dissolved in oil. The distribution of moisture between paper and oil is not static, but varies depending on the insulation temperature, and thus, water migration processes take place continuously during transformers operation. In this work, a sensor is presented that allows the determination of the moisture content of the transformer solid insulation in the steady state and during the moisture migration processes. The main objective of the design is that the electrodes of the sensor should not obstruct the movement of water from the solid insulation to the oil, so the proposed prototype uses a metallic-mesh electrode to do the measurements. The measurement setup is based on the characterization of the insulation dielectric response by means of the frequency dielectric spectroscopy (FDS) method. The sensitivity of the proposed sensor has been tested on samples with a moisture content within 1% to 5%, demonstrating the good sensitivity and repeatability of the measurements.

Prediction of the Effective Thermal Conductivity of Powder Insulation

NASA Astrophysics Data System (ADS)

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

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

Report of sampling and analysis results, Addison Army housing units, Addison, Illinois. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1990-09-01

The objectives of this sampling and analysis effort include further characterization of environmental contamination identified in an enhanced preliminary assessment carried out in 1989. The specific activities performed at this site were identification, evaluation of the condition, and collection of samples from specific suspected asbestos-containing materials, including floor tiles, pipe run and pipe fitting insulation, dust in the ductwork, and exterior siding, where present. These evaluation were necessary to clarify potential environmental issues identified in the earlier report, prior to the sale or realignment of the property.

Thermal/acoustical aircraft insulation material

NASA Technical Reports Server (NTRS)

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

1975-01-01

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

Localized solar collectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghasemi, Hadi; Marconnet, Amy Marie; Chen, Gang

A localized heating structure, and method of forming same, for use in solar systems includes a thermally insulating layer having interconnected pores, a density of less than about 3000 kg/m.sup.3, and a hydrophilic surface, and an expanded carbon structure adjacent to the thermally insulating layer. The expanded carbon structure has a porosity of greater than about 80% and a hydrophilic surface.

Charge Storage, Conductivity and Charge Profiles of Insulators as Related to Spacecraft Charging

NASA Technical Reports Server (NTRS)

Dennison, J. R.; Swaminathan, Prasanna; Frederickson, A. R.

2004-01-01

Dissipation of charges built up near the surface of insulators due to space environment interaction is central to understanding spacecraft charging. Conductivity of insulating materials is key to determine how accumulated charge will distribute across the spacecraft and how rapidly charge imbalance will dissipate. To understand these processes requires knowledge of how charge is deposited within the insulator, the mechanisms for charge trapping and charge transport within the insulator, and how the profile of trapped charge affects the transport and emission of charges from insulators. One must consider generation of mobile electrons and holes, their trapping, thermal de-trapping, mobility and recombination. Conductivity is more appropriately measured for spacecraft charging applications as the "decay" of charge deposited on the surface of an insulator, rather than by flow of current across two electrodes around the sample. We have found that conductivity determined from charge storage decay methods is 102 to 104 smaller than values obtained from classical ASTM and IEC methods for a variety of thin film insulating samples. For typical spacecraft charging conditions, classical conductivity predicts decay times on the order of minutes to hours (less than typical orbit periods); however, the higher charge storage conductivities predict decay times on the order of weeks to months leading to accumulation of charge with subsequent orbits. We found experimental evidence that penetration profiles of radiation and light are exceedingly important, and that internal electric fields due to charge profiles and high-field conduction by trapped electrons must be considered for space applications. We have also studied whether the decay constants depend on incident voltage and flux or on internal charge distributions and electric fields; light-activated discharge of surface charge to distinguish among differing charge trapping centers; and radiation-induced conductivity. Our experiments also show that "Malter" electron emission occurs for hours after turning off the electron beam. This Malter emission similar to emission due to negative electron affinity in semiconductors is a result of the prior radiation or optical excitations of valence electrons and their slow drift among traps towards the surface where they are subsequently emitted. This work is supported through funding from the NASA Space Environments and Effects Program.

Reliability of spring interconnects for high channel-count polyimide electrode arrays

NASA Astrophysics Data System (ADS)

Khan, Sharif; Ordonez, Juan Sebastian; Stieglitz, Thomas

2018-05-01

Active neural implants with a high channel-count need robust and reliable operational assembly for the targeted environment in order to be classified as viable fully implantable systems. The discrete functionality of the electrode array and the implant electronics is vital for intact assembly. A critical interface exists at the interconnection sites between the electrode array and the implant electronics, especially in hybrid assemblies (e.g. retinal implants) where electrodes and electronics are not on the same substrate. Since the interconnects in such assemblies cannot be hermetically sealed, reliable protection against the physiological environment is essential for delivering high insulation resistance and low defusibility of salt ions, which are limited in complexity by current assembly techniques. This work reports on a combination of spring-type interconnects on a polyimide array with silicone rubber gasket insulation for chronically active implantable systems. The spring design of the interconnects on the backend of the electrode array compensates for the uniform thickness of the sandwiched gasket during bonding in assembly and relieves the propagation of extrinsic stresses to the bulk polyimide substrate. The contact resistance of the microflex-bonded spring interconnects with the underlying metallized ceramic test vehicles and insulation through the gasket between adjacent contacts was investigated against the MIL883 standard. The contact and insulation resistances remained stable in the exhausting environmental conditions.

Advanced Insulation for High Performance Cost-Effective Wall, Roof, and Foundation Systems Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Costeux, Stephane; Bunker, Shanon

The objective of this project was to explore and potentially develop high performing insulation with increased R/inch and low impact on climate change that would help design highly insulating building envelope systems with more durable performance and lower overall system cost than envelopes with equivalent performance made with materials available today. The proposed technical approach relied on insulation foams with nanoscale pores (about 100 nm in size) in which heat transfer will be decreased. Through the development of new foaming methods, of new polymer formulations and new analytical techniques, and by advancing the understanding of how cells nucleate, expand andmore » stabilize at the nanoscale, Dow successfully invented and developed methods to produce foams with 100 nm cells and 80% porosity by batch foaming at the laboratory scale. Measurements of the gas conductivity on small nanofoam specimen confirmed quantitatively the benefit of nanoscale cells (Knudsen effect) to increase insulation value, which was the key technical hypotheses of the program. In order to bring this technology closer to a viable semi-continuous/continuous process, the project team modified an existing continuous extrusion foaming process as well as designed and built a custom system to produce 6" x 6" foam panels. Dow demonstrated for the first time that nanofoams can be produced in a both processes. However, due to technical delays, foam characteristics achieved so far fall short of the 100 nm target set for optimal insulation foams. In parallel with the technology development, effort was directed to the determination of most promising applications for nanocellular insulation foam. Voice of Customer (VOC) exercise confirmed that demand for high-R value product will rise due to building code increased requirements in the near future, but that acceptance for novel products by building industry may be slow. Partnerships with green builders, initial launches in smaller markets (e.g. EIFS), and efforts to drive cost down will help acceptance in residential and commercial retrofit and new construction.« less

Mechanism and influencing factors on critical pulse width of oil-immersed polymer insulators under short pulses

NASA Astrophysics Data System (ADS)

Zhao, Liang; Su, Jian Cang; Li, Rui; Zeng, Bo; Cheng, Jie; Zheng, Lei; Yu, Bin Xiong; Wu, Xiao Long; Zhang, Xi Bo; Pan, Ya Feng

2015-04-01

The critical pulse width (τc) is a pulse width at which the surface flashover threshold (Ef) is equal to the bulk breakdown threshold (EBD) for liquid-polymer composite insulation systems, which is discovered by Zhao et al. [Annual Report Conference on Electrical Insulation and Dielectric Phenomena (IEEE Dielectrics and Electrical Insulation Society, Shenzhen, China, 2013), Vol. 2, pp. 854-857]. In this paper, the mechanism of τc is interpreted in perspective of the threshold and the time delay (td) of surface flashover and bulk breakdown, respectively. It is found that two changes appear as the pulse width decreases which are responsible for the existence of τc: (1) EBD is lower than Ef; (2) td of bulk breakdown is shorter than td of surface flashover. In addition, factors which have influences on τc are investigated, such as the dielectric type, the insulation length, the dielectric thickness, the dielectrics configuration, the pulse number, and the liquid purity. These influences of factors are generalized as three types if τc is expected to increase: (1) factors causing EBD to decrease, such as increasing the pulse number or employing a dielectric of lower EBD; (2) factors causing Ef to increase, such as complicating the insulator's configuration or increasing the liquid purity; (3) factors causing EBD and Ef to increase together, but Ef increases faster than EBD, such as decreasing the dielectric thickness or the insulation length. With the data in references, all the three cases are verified experimentally. In the end, a general method based on τc for solid insulation design is presented and the significance of τc on solid insulation design and on solid demolition are discussed.

Investigation of Expandable Polymeric Microspheres for Packaging Applications

DTIC Science & Technology

2012-06-06

FILMS COST REDUCTION OLEFIN POLYMERS COSTS PACKAGING MICROSPHERES WASTE DISPOSAL WEIGHT...MANAGEMENT THERMAL INSULATION DENSITY SOLID WASTES ENVIRONMENTAL IMPACT THERMOPLASTIC POLYMERS POLYMERS ...research. The purpose was to provide information on the incorporation of hollow, expandable  polymeric microspheres  into  thermoplastic   polymers   to

Semiconductor of spinons: from Ising band insulator to orthogonal band insulator.

PubMed

Farajollahpour, T; Jafari, S A

2018-01-10

We use the ionic Hubbard model to study the effects of strong correlations on a two-dimensional semiconductor. The spectral gap in the limit where on-site interactions are zero is set by the staggered ionic potential, while in the strong interaction limit it is set by the Hubbard U. Combining mean field solutions of the slave spin and slave rotor methods, we propose two interesting gapped phases in between: (i) the insulating phase before the Mott phase can be viewed as gapping a non-Fermi liquid state of spinons by the staggered ionic potential. The quasi-particles of underlying spinons are orthogonal to physical electrons, giving rise to the 'ARPES-dark' state where the ARPES gap will be larger than the optical and thermal gap. (ii) The Ising insulator corresponding to ordered phase of the Ising variable is characterized by single-particle excitations whose dispersion is controlled by Ising-like temperature and field dependences. The temperature can be conveniently employed to drive a phase transition between these two insulating phases where Ising exponents become measurable by ARPES and cyclotron resonance. The rare earth monochalcogenide semiconductors where the magneto-resistance is anomalously large can be a candidate system for the Ising band insulator. We argue that the Ising and orthogonal insulating phases require strong enough ionic potential to survive the downward renormalization of the ionic potential caused by Hubbard U.

Semiconductor of spinons: from Ising band insulator to orthogonal band insulator

NASA Astrophysics Data System (ADS)

Farajollahpour, T.; Jafari, S. A.

2018-01-01

We use the ionic Hubbard model to study the effects of strong correlations on a two-dimensional semiconductor. The spectral gap in the limit where on-site interactions are zero is set by the staggered ionic potential, while in the strong interaction limit it is set by the Hubbard U. Combining mean field solutions of the slave spin and slave rotor methods, we propose two interesting gapped phases in between: (i) the insulating phase before the Mott phase can be viewed as gapping a non-Fermi liquid state of spinons by the staggered ionic potential. The quasi-particles of underlying spinons are orthogonal to physical electrons, giving rise to the ‘ARPES-dark’ state where the ARPES gap will be larger than the optical and thermal gap. (ii) The Ising insulator corresponding to ordered phase of the Ising variable is characterized by single-particle excitations whose dispersion is controlled by Ising-like temperature and field dependences. The temperature can be conveniently employed to drive a phase transition between these two insulating phases where Ising exponents become measurable by ARPES and cyclotron resonance. The rare earth monochalcogenide semiconductors where the magneto-resistance is anomalously large can be a candidate system for the Ising band insulator. We argue that the Ising and orthogonal insulating phases require strong enough ionic potential to survive the downward renormalization of the ionic potential caused by Hubbard U.

Fabrication and Characterization of ZnO Langmuir-Blodgett Film and Its Use in Metal-Insulator-Metal Tunnel Diode.

PubMed

Azad, Ibrahim; Ram, Manoj K; Goswami, D Yogi; Stefanakos, Elias

2016-08-23

Metal-insulator-metal tunnel diodes have great potential for use in infrared detection and energy harvesting applications. The quantum based tunneling mechanism of electrons in MIM (metal-insulator-metal) or MIIM (metal-insulator-insulator-metal) diodes can facilitate rectification at THz frequencies. In this study, the required nanometer thin insulating layer (I) in the MIM diode structure was fabricated using the Langmuir-Blodgett technique. The zinc stearate LB film was deposited on Au/Cr coated quartz, FTO, and silicon substrates, and then heat treated by varying the temperature from 100 to 550 °C to obtain nanometer thin ZnO layers. The thin films were characterized by XRD, AFM, FTIR, and cyclic voltammetry methods. The final MIM structure was fabricated by depositing chromium/nickel over the ZnO on Au/Cr film. The current voltage (I-V) characteristics of the diode showed that the conduction mechanism is electron tunneling through the thin insulating layer. The sensitivity of the diodes was as high as 32 V(-1). The diode resistance was ∼80 Ω (at a bias voltage of 0.78 V), and the rectification ratio at that bias point was about 12 (for a voltage swing of ±200 mV). The diode response exhibited significant nonlinearity and high asymmetry at the bias point, very desirable diode performance parameters for IR detection applications.

Numerical Computation of Electric Field and Potential Along Silicone Rubber Insulators Under Contaminated and Dry Band Conditions

NASA Astrophysics Data System (ADS)

Arshad; Nekahi, A.; McMeekin, S. G.; Farzaneh, M.

2016-09-01

Electrical field distribution along the insulator surface is considered one of the important parameters for the performance evaluation of outdoor insulators. In this paper numerical simulations were carried out to investigate the electric field and potential distribution along silicone rubber insulators under various polluted and dry band conditions. Simulations were performed using commercially available simulation package Comsol Multiphysics based on the finite element method. Various pollution severity levels were simulated by changing the conductivity of pollution layer. Dry bands of 2 cm width were inserted at the high voltage end, ground end, middle part, shed, sheath, and at the junction of shed and sheath to investigate the effect of dry band location and width on electric field and potential distribution. Partial pollution conditions were simulated by applying pollution layer on the top and bottom surface respectively. It was observed from the simulation results that electric field intensity was higher at the metal electrode ends and at the junction of dry bands. Simulation results showed that potential distribution is nonlinear in the case of clean and partially polluted insulator and linear for uniform pollution layer. Dry band formation effect both potential and electric field distribution. Power dissipated along the insulator surface and the resultant heat generation was also studied. The results of this study could be useful in the selection of polymeric insulators for contaminated environments.

Volatility and Uncertainty in Environmental Policy

NASA Astrophysics Data System (ADS)

Maniloff, Peter Taylor

Environmental policy is increasingly implemented via market mechanisms. While this is in many ways a great success for the economics profession, a number of questions remain. In this dissertation, I empirically explore the question of what will happen as environmental outcomes are coupled to potentially volatile market phenomena, whether policies can insulate environmental outcomes and market shocks, and policymakers should act to mitigate such volatility. I use a variety of empirical methods including reduced form and structural econometrics as well as theoretical models to consider a variety of policy, market, and institutional contexts. The effectiveness of market interventions depends on the context and on the policy mechanism. In particular, energy markets are characterized by low demand elasticities and kinked supply curves which are very flat below a capacity constraint (elastic) and very steep above it (inelastic). This means that a quantity-based policy that acts on demand, such as releasing additional pollution emission allowances from a reserved fund would be an effective way to constrain price shocks in a cap-and-trade system. However, a quantity-based policy that lowers the need for inframarginal supply, such as using ethanol as an oil product substitute to mitigate oil shocks, would be ineffective. Similarly, the benefits of such interventions depends on the macroeconomic impacts of price shocks from the sector. Relatedly, I show that a liability rule designed to reduce risk from low-probability, high-consequence oil spills have very low compliance costs.

Fabrication of Ta2O5/GeNx gate insulator stack for Ge metal-insulator-semiconductor structures by electron-cyclotron-resonance plasma nitridation and sputtering deposition techniques

NASA Astrophysics Data System (ADS)

Otani, Yohei; Itayama, Yasuhiro; Tanaka, Takuo; Fukuda, Yukio; Toyota, Hiroshi; Ono, Toshiro; Mitsui, Minoru; Nakagawa, Kiyokazu

2007-04-01

The authors have fabricated germanium (Ge) metal-insulator-semiconductor (MIS) structures with a 7-nm-thick tantalum pentaoxide (Ta2O5)/2-nm-thick germanium nitride (GeNx) gate insulator stack by electron-cyclotron-resonance plasma nitridation and sputtering deposition. They found that pure GeNx ultrathin layers can be formed by the direct plasma nitridation of the Ge surface without substrate heating. X-ray photoelectron spectroscopy revealed no oxidation of the GeNx layer after the Ta2O5 sputtering deposition. The fabricated MIS capacitor with a capacitance equivalent thickness of 4.3nm showed excellent leakage current characteristics. The interface trap density obtained by the modified conductance method was 4×1011cm-2eV-1 at the midgap.

Cryogenic insulation strength and bond tester

NASA Technical Reports Server (NTRS)

Schuerer, P. H.; Ehl, J. H.; Prasthofer, W. P. (Inventor)

1985-01-01

A method and apparatus for testing the tensile strength and bonding strength of sprayed-on foam insulation attached to metal cryogenic fuel tanks is described. A circular cutter is used to cut the insulation down to the surface of the metal tank to form plugs of the insulation for testing in situ on the tank. The apparatus comprises an electromechanical pulling device powered by a belt battery pack. The pulling device comprises a motor driving a mechanical pulling structure comprising a horizontal shaft connected to two bell cracks which are connected to a central member. When the lower end of member is attached to a fitting, which in turn is bonded to a plug, a pulling force is exerted on the plug sufficient to rupture it. The force necessary to rupture the plug or pull it loose is displayed as a digital read-out.

Development of automatic through-insulation welding for microelectric interconnections

NASA Technical Reports Server (NTRS)

Arnett, J. C.

1972-01-01

The capability to automatically route, remove insulation from, and weld small-diameter solid conductor wire is presented. This would facilitate the economical small-quantity production of complex miniature electronic assemblies. An engineering model of equipment having this capability was developed and evaluated. Whereas early work in the use of welded magnet wire interconnections was concentrated on opposed electrode systems, and generally used heat to melt the wire insulation, the present method is based on a concentric electrode system and a wire feed system which splits the insulation by application of pressure prior to welding. The work deals with the design, fabrication, and evaluation testing of an improved version of this concentric electrode system. Two different approaches to feeding the wire to the concentric electrodes were investigated. It was concluded that the process is feasible for the interconnection of complex miniature electronic assemblies.

Local Peltier-effect-induced reversible metal–insulator transition in VO{sub 2} nanowires

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takami, Hidefumi; Kanki, Teruo, E-mail: kanki@sanken.osaka-u.ac.jp, E-mail: h-tanaka@sanken.osaka-u.ac.jp; Tanaka, Hidekazu, E-mail: kanki@sanken.osaka-u.ac.jp, E-mail: h-tanaka@sanken.osaka-u.ac.jp

2016-06-15

We report anomalous resistance leaps and drops in VO{sub 2} nanowires with operating current density and direction, showing reversible and nonvolatile switching. This event is associated with the metal–insulator phase transition (MIT) of local nanodomains with coexistence states of metallic and insulating phases induced by thermoelectric cooling and heating effects. Because the interface of metal and insulator domains has much different Peltier coefficient, it is possible that a significant Peltier effect would be a source of the local MIT. This operation can be realized by one-dimensional domain configuration in VO{sub 2} nanowires because one straight current path through the electronicmore » domain-interface enables theoretical control of thermoelectric effects. This result will open a new method of reversible control of electronic states in correlated electron materials.« less

Global Phase Diagram of a Three-Dimensional Dirty Topological Superconductor

NASA Astrophysics Data System (ADS)

Roy, Bitan; Alavirad, Yahya; Sau, Jay D.

2017-06-01

We investigate the phase diagram of a three-dimensional, time-reversal symmetric topological superconductor in the presence of charge impurities and random s -wave pairing. Combining complimentary field theoretic and numerical methods, we show that the quantum phase transition between two topologically distinct paired states (or thermal insulators), described by thermal Dirac semimetal, remains unaffected in the presence of sufficiently weak generic randomness. At stronger disorder, however, these two phases are separated by an intervening thermal metallic phase of diffusive Majorana fermions. We show that across the insulator-insulator and metal-insulator transitions, normalized thermal conductance displays single parameter scaling, allowing us to numerically extract the critical exponents across them. The pertinence of our study in strong spin-orbit coupled, three-dimensional doped narrow gap semiconductors, such as CuxBi2Se3 , is discussed.

Breakdown Voltage of CF3CHCl2 gas an Alternative to SF6 Gas using HV Test and Bonding Energy Methods

NASA Astrophysics Data System (ADS)

Juliandhy, Tedy; Haryono, T.; Suharyanto; Perdana, Indra

2018-04-01

For more than two decades of Sulphur Hexafluoride (SF6) gases is used as a gas insulation in high voltage equipment especially in substations. In addition to getting an advantage as an insulating gas. SF6 gas is recognized as one of the greenhouse effect gases that cause global warming. Under the Kyoto Protocol, SF6 gas is one of those gases whose use is restricted and gradually reduced to the presence of a replacement gas for SF6 gas. One of the alternative gas alternatives which have the potential of replacing SF6 gas as an insulating gas in Gas Insulated Switchgear (GIS) equipment in the substation is Dichlorotrifluoroethane (CF3CHCl2) gas. The purpose of this paper is to enable a comparison of breakdown voltage with high voltage test and method of calculating Bonding energy to Dichlorotrifluoroethane gas as substitute gas for SF6 gas. At 0.1 bar gas pressure obtained an average breakdown voltage of 18.68 kV / mm at 25oC chamber temperature and has the highest breakdown voltage at 50oC with a breakdown voltage of 19.56 kV / mm. The CF3CHCl2 gas has great potential as an insulating gas because it has more insulation ability high of SF6 gas, and is part of the gas recommended under the Kyoto Protocol. Gas CF3CHCl2 has the capacity to double the value of electronegativity greater than SF6 gas as a major requirement of gas isolation and has a value of Global Warming Potential (GWP) and Ozone Depleting lower than from SF6 gas.

Graphene-insulator-semiconductor capacitors as superior test structures for photoelectric determination of semiconductor devices band diagrams

NASA Astrophysics Data System (ADS)

Piskorski, K.; Passi, V.; Ruhkopf, J.; Lemme, M. C.; Przewlocki, H. M.

2018-05-01

We report on the advantages of using Graphene-Insulator-Semiconductor (GIS) instead of Metal-Insulator-Semiconductor (MIS) structures in reliable and precise photoelectric determination of the band alignment at the semiconductor-insulator interface and of the insulator band gap determination. Due to the high transparency to light of the graphene gate in GIS structures large photocurrents due to emission of both electrons and holes from the substrate and negligible photocurrents due to emission of carriers from the gate can be obtained, which allows reliable determination of barrier heights for both electrons, Ee and holes, Eh from the semiconductor substrate. Knowing the values of both Ee and Eh allows direct determination of the insulator band gap EG(I). Photoelectric measurements were made of a series of Graphene-SiO2-Si structures and an example is shown of the results obtained in sequential measurements of the same structure giving the following barrier height values: Ee = 4.34 ± 0.01 eV and Eh = 4.70 ± 0.03 eV. Based on this result and results obtained for other structures in the series we conservatively estimate the maximum uncertainty of both barrier heights estimations at ± 0.05 eV. This sets the SiO2 band gap estimation at EG(I) = 7.92 ± 0.1 eV. It is shown that widely different SiO2 band gap values were found by research groups using various determination methods. We hypothesize that these differences are due to different sensitivities of measurement methods used to the existence of the SiO2 valence band tail.

LONG TERM OPERATION ISSUES FOR ELECTRICAL CABLE SYSTEMS IN NUCLEAR POWER PLANTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fifield, Dr Leonard S; Duckworth, Robert C; Glass III, Dr. Samuel W.

Nuclear power plants contain hundreds of kilometers of electrical cables including cables used for power, for instrumentation, and for control. It is essential that safety-related cable systems continue to perform following a design-basis event. Wholesale replacement of electrical cables in existing plants facing licensing period renewal is both impractical and cost-prohibitive. It is therefore important to understand the long term aging of cable materials to have confidence that aged cables will perform when needed. It is equally important in support of cable aging management to develop methods to evaluate the health of installed cables and inform selective cable replacement decisions.more » The most common insulation materials for electrical cables in nuclear power plants are cross-linked polyethylene and ethylene-propylene rubber. The mechanical properties of these materials degrade over time in the presence of environmental stresses including heat, gamma irradiation, and moisture. Mechanical degradation of cable insulation beyond a certain threshold is unacceptable because it can lead to insulation cracking, exposure of energized conductors, arcing and burning or loss of the ability of the cable system to function during a design-basis accident. While thermal-, radiation-, and moisture-related degradation of polymer insulation materials has been extensively studied over the last few decades, questions remain regarding the long-term performance of cable materials in nuclear plant-specific environments. Identified knowledge gaps include an understanding of the temperature-dependence of activation energies for thermal damage and an understanding of the synergistic effects of radiation and thermal stress on polymer degradation. Many of the outstanding questions in the aging behavior of cable materials relate to the necessity of predicting long-term field degradation using accelerated aging results from the laboratory. Materials degrade faster under more extreme conditions, but extension of behavior to long term degradation under more mild conditions, such as those experienced by most installed cables in nuclear power plants, is complicated by the fact that different degradation mechanisms may be involved in extreme and mild scenarios. The discrepancy in predicted results from short term, more extreme exposure and actual results from longer term, more mild exposures can be counter intuitive. For instance, due to the attenuation of oxidation penetration in material samples rapidly aged through exposure to high temperatures, the bulk of the samples may be artificially protected from thermal aging. In another example, simultaneous exposure of cable insulation material to heat and radiation may actually lead to less damage at higher temperatures than may be observed at lower temperatures. The Light Water Reactor Sustainability program of the United States (US) Department of Energy Office (DOE) of Nuclear Energy is funding research to increase the predictive understanding of electrical cable material aging and degradation in existing nuclear power plants in support of continued safe operation of plants beyond their initial license periods. This research includes the evaluation and development of methods to assess installed cable condition.« less

Building America Case Study: Excavationless Exterior-Side Foundation Insulation for Existing Homes, Minneapolis, Minnesota (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

NorthernSTAR

Building science research supports installing exterior (soil side) foundation insulation as the optimal method to enhance the hygrothermal performance of new homes. With exterior foundation insulation, water management strategies are maximized while insulating the basement space and ensuring a more even temperature at the foundation wall. However, such an approach can be very costly and disruptive when applied to an existing home, requiring deep excavation around the entire house. The NorthernSTAR Building America Partnership team implemented an innovative, minimally invasive foundation insulation upgrade technique on an existing home. The approach consisted of using hydrovac excavation technology combined with a liquidmore » insulating foam. The team was able to excavate a continuous 4" wide by 4' to 5' deep trench around the entire house, 128 linear feet, except for one small part under the stoop that was obstructed with concrete debris. The combination pressure washer and vacuum extraction technology also enabled the elimination of large trenches and soil stockpiles normally produced by backhoe excavation. The resulting trench was filled with liquid insulating foam, which also served as a water-control layer of the assembly. The insulation was brought above grade using a liquid foam/rigid foam hybrid system and terminated at the top of the rim joist. Cost savings over the traditional excavation process ranged from 23% to 50%. The excavationless process could result in even greater savings since replacement of building structures, exterior features, utility meters, and landscaping would be minimal or non-existent in an excavationless process.« less

Effects of RTV coating on the electrical performance of polymer insulator under lightning impulse voltage condition.

PubMed

Jamaludin, Farah Adilah; Ab-Kadir, Mohd Zainal Abidin; Izadi, Mahdi; Azis, Norhafiz; Jasni, Jasronita; Abd-Rahman, Muhammad Syahmi

2017-01-01

Located near the equator, Malaysia is a country with one of the highest lightning densities in the world. Lightning contributes to 70% of the power outages in Malaysia and affects power equipment, automated network systems, causes data losses and monetary losses in the nation. Therefore, consideration of insulator evaluation under lightning impulses can be crucial to evaluate and attempt to overcome this issue. This paper presents a new approach to increase the electrical performance of polymer insulators using a Room Temperature Vulcanisation (RTV) coating. The evaluation involves three different settings of polymer insulator, namely uncoated, RTV type 1, and RTV type 2 upper surface coatings. All the insulators were tested under three different conditions as dry, clean wet and salty under different impulse polarities using the even-rising test method. The voltage breakdown for each test was recorded. From the experiment, it was found that the effectiveness of the RTV coating application became apparent when tested under salty or polluted conditions. It increased the voltage withstand capabilities of the polymer insulator up to 50% from the basic uncoated insulator. Under dry and clean conditions, the RTV coating provided just a slight increase of the breakdown voltage. The increase in voltage breakdown capability decreased the probability of surface discharge and dry band arcing that could cause degradation of the polymeric material housing. The RTV type 1 coating was found to be more effective when performing under a lightning impulse. The findings might help the utility companies improve the performance of their insulators in order to increase power system reliability.

Effects of RTV coating on the electrical performance of polymer insulator under lightning impulse voltage condition

PubMed Central

Jamaludin, Farah Adilah; Ab-Kadir, Mohd Zainal Abidin; Izadi, Mahdi; Azis, Norhafiz; Jasni, Jasronita; Abd-Rahman, Muhammad Syahmi

2017-01-01

Located near the equator, Malaysia is a country with one of the highest lightning densities in the world. Lightning contributes to 70% of the power outages in Malaysia and affects power equipment, automated network systems, causes data losses and monetary losses in the nation. Therefore, consideration of insulator evaluation under lightning impulses can be crucial to evaluate and attempt to overcome this issue. This paper presents a new approach to increase the electrical performance of polymer insulators using a Room Temperature Vulcanisation (RTV) coating. The evaluation involves three different settings of polymer insulator, namely uncoated, RTV type 1, and RTV type 2 upper surface coatings. All the insulators were tested under three different conditions as dry, clean wet and salty under different impulse polarities using the even-rising test method. The voltage breakdown for each test was recorded. From the experiment, it was found that the effectiveness of the RTV coating application became apparent when tested under salty or polluted conditions. It increased the voltage withstand capabilities of the polymer insulator up to 50% from the basic uncoated insulator. Under dry and clean conditions, the RTV coating provided just a slight increase of the breakdown voltage. The increase in voltage breakdown capability decreased the probability of surface discharge and dry band arcing that could cause degradation of the polymeric material housing. The RTV type 1 coating was found to be more effective when performing under a lightning impulse. The findings might help the utility companies improve the performance of their insulators in order to increase power system reliability. PMID:29136025

Transportation of perishable and refrigerated foods in mylar foil bags and insulated containers: a time-temperature study.

PubMed

Li, Yanyan; Schrade, John P; Su, Haiyan; Specchio, John J

2014-08-01

Data are lacking on the temperature changes of food during transport without the use of refrigerated trucks. The purpose of this study was to evaluate the ability of several insulated and noninsulated containers with or without frozen gel packs to keep perishable and refrigerated foods within the temperature safe zone in relationship to duration of transport. The study was designed to duplicate the practices exhibited by customers purchasing perishable food products from a cash-and-carry business. Approximately 40 perishable food items were evaluated. Four types of containers were tested: a mylar foil bag, a commercial insulated bag, a generic insulated bag, and a commercial insulated blanket. Mixed foods were placed into these containers with or without frozen gel packs, transported in unrefrigerated vehicles, and monitored for 4 h for temperature changes. Two environmental temperatures, room temperature of 21.1°C and a stress temperature of 37.8°C, were evaluated. The internal temperature and surface temperature of the food products in these containers increased slowly but remained well below the U.S. Food and Drug Administration Food Code requirements. The various containers were similar in their ability to retain coolness. The presence of frozen gel packs dramatically enhanced the cold-holding capacity of the containers. The temperature of foods increased more rapidly when stressed in a heated environment. The containers tested used with the frozen gel packs can keep the surface and internal temperatures of various perishable foods (starting at 4.4°C or less) within the Food Code recommendation of under 21.1°C for 4 h. Cash-and-carry businesses should strongly encourage their retail customers to utilize these containers with frozen gel packs to safely transport perishable foods.

Method for electrically isolating an electrically conductive member from another such member

DOEpatents

Tsang, K.L.; Chen, Y.

1984-02-09

The invention relates to methods for electrically isolating a first electrically conductive member from another such member by means of an electrically insulating medium. In accordance with the invention, the insulating medium is provided in the form of MgO which contains a dopant selected from lithium, copper, cobalt, sodium, silver, gold and hydrogen. The dopant is present in the MgO in an amount effective to suppress dielectric breakdown of the MgO, even at elevated temperatures and in the presence of electrical fields.