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Sample records for insulation resistance ir

  1. Utilidad del índice HOMA-IR con una sola determinación de insulinemia para diagnosticar resistencia insulínica Usefulness of HOMA-IR index with an only insulinemia determination to diagnose an insulin resistance

    Directory of Open Access Journals (Sweden)

    José Arturo Hernández Yero

    2011-08-01

    Full Text Available Introducción: el índice HOMA-IR es un procedimiento simple, poco invasivo, y que permite, mediante una fórmula validada y bien establecida, precisar un valor numérico expresivo de resistencia insulínica. Calcular el índice HOMA-IR con un solo valor de insulinemia pudiera presentar una mayor variabilidad, lo cual se trata de solucionar con al menos la media de 3 insulinemias, de acuerdo con la fórmula original. En varios estudios es habitual que se realice con una sola determinación de insulinemia. Por esa razón se decidió hacer un estudio en pacientes con diabetes tipo 2 y comparar los resultados en cuanto a sensibilidad y especificidad con una sola determinación de sangre para la insulinemia y glucemia. Objetivo: evaluar la sensibilidad y especificidad de cada una de las determinaciones de insulinemia realizadas cada 5 min contra la media de estas durante la aplicación de la fórmula para el índice HOMA-IR. Métodos: se estudiaron 60 pacientes con diagnóstico de diabetes tipo 2, que acudieron a los servicios de consulta externa y de orientación en el Centro de Atención al Diabético de La Habana. Tenían un tiempo de evolución de la diabetes menor de 5 años como promedio, con predominio en el sobrepeso corporal, fueron captados en un período de 6 meses de forma consecutiva, y se les realizaron determinaciones de insulinemias y glucemias en ayunas mediante trocar y extracción de sangre venosa a los 0,5 y 10 min, para realizarles el cálculo del modelo homeostático de Matthews conocido como HOMA-IR. Resultados: un 88,3 % tenía un HOMA-IR mayor de 3,2. La sensibilidad de una sola muestra de insulinemia, aunque elevada para confirmar el diagnóstico de resistencia insulínica, es variable, y la especificidad de una de las muestras resultó baja con un 14 %. Se aprecia una adecuada concordancia entre los valores predictivos positivos con la sensibilidad y los valores predictivos negativos con la especificidad de la prueba

  2. Radiation-resistant plastic insulators

    International Nuclear Information System (INIS)

    Sturm, B.J.; Parkinson, W.W.

    1975-01-01

    A high molecular weight organic composition useful as an electric insulator in radiation fields is provided and comprises normally a solid polymer of an organic compound having a specific resistance greater than 10 19 ohm-cm and containing phenyl groups and 1 to 7.5 weight percent of a high molecular weight organic phosphite. In one embodiment the composition comprises normally solid polystyrene having 7.5 weight percent tris-β-chloroethyl phosphite as an additive; the composition exhibited an increase in the post-irradiation resistivity of over an order of magnitude over the post-irradiation resistivity of pure polystyrene. (Patent Office Record)

  3. Electrical resistivity study of insulators

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  4. Surface electrical resistivity of insulators

    International Nuclear Information System (INIS)

    Senn, B. C.; Liesegang, J.

    1996-01-01

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

  5. Insulating materials resistance in intense radiation beams

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  6. Insulating phase in Sr{sub 2}IrO{sub 4}: An investigation using critical analysis and magnetocaloric effect

    Energy Technology Data Exchange (ETDEWEB)

    Bhatti, Imtiaz Noor; Pramanik, A.K., E-mail: akpramanik@mail.jnu.ac.in

    2017-01-15

    The nature of insulating phase in 5d based Sr{sub 2}IrO{sub 4} is quite debated as the theoretical as well as experimental investigations have put forward evidences in favor of both magnetically driven Slater-type and interaction driven Mott-type insulator. To understand this insulating behavior, we have investigated the nature of magnetic state in Sr{sub 2}IrO{sub 4} through studying critical exponents, low temperature thermal demagnetization and magnetocaloric effect. The estimated critical exponents do not exactly match with any universality class, however, the values obey the scaling behavior. The exponent values suggest that spin interaction in present material is close to mean-field model. The analysis of low temperature thermal demagnetization data, however, shows dual presence of localized- and itinerant-type of magnetic interaction. Moreover, field dependent change in magnetic entropy indicates magnetic interaction is close to mean-field type. While this material shows an insulating behavior across the magnetic transition, yet a distinct change in slope in resistivity is observed around T{sub c}. We infer that though the insulating phase in Sr{sub 2}IrO{sub 4} is more close to be Slater-type but the simultaneous presence of both Slater- and Mott-type is the likely scenario for this material. - Highlights: • Critical analysis shows Sr{sub 2}IrO{sub 4} has ferromagnetic ordering temperature T{sub c}~225 K. • Obtained critical exponents imply spin interaction is close to mean-field model. • Analysis of magneto-entropy data also supports mean-field type interaction. • However, the presence of both itinerant and localized spin interaction is evident. • Sr{sub 2}IrO{sub 4} has simultaneous presence of both Slater- and Mott-type insulating phase.

  7. 49 CFR 236.527 - Roadway element insulation resistance.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Roadway element insulation resistance. 236.527 Section 236.527 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... element insulation resistance. Insulation resistance between roadway inductor and ground shall be...

  8. Development of radiation resistant PEEK insulation cable

    International Nuclear Information System (INIS)

    Mio, Keigo; Ogiwara, Norio; Hikichi, Yusuke; Furukori, Hisayoshi; Arai, Hideyuki; Nishizawa, Daiji; Nishidono, Toshiro

    2009-04-01

    Material characterization and development has been carried out for cable insulation suitable for use in the J-PARC 3-GeV RCS radiation environment. In spite of its high cost, PEEK (polyether-ether-ketone) has emerged as the leading candidate satisfying requirements of being non-halogen based, highly incombustible and with radiation resistant at least 10 MGy, along with the usual mechanical characteristics such as good elongation at break, which are needed in a cable insulation. Gamma-ray irradiation tests have been done in order to study radiation resistance of PEEK cable. Further, mechanical, electrical and fire retardant characteristics of a complete cable such as would be used at the J-PARC RCS were investigated. As a result, PEEK cables were shown to be not degraded by radiation up to at least 10 MGy, and thus could be expected to operate stably under the 3-GeV RCS radiation environment. (author)

  9. Insulin resistance index (HOMA-IR in the differentiation of patients with non-alcoholic fatty liver disease and healthy individuals Índice de resistência insulínica (HOMA-IR na diferenciação entre pacientes com doença hepática gordurosa não-alcoólica e indivíduos saudáveis

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Farias de Azevedo Salgado

    2010-06-01

    Full Text Available CONTEXT: Due to its good correlation to glycemic clamp, HOMA-IR has been widely utilized as insulin resistance index in clinical and epidemiological studies involving non-alcoholic fatty liver disease carriers. However, values used for this parameter have shown large variability. OBJECTIVE: To identify the HOMA-IR cut value that best distinguishes non-diabetic non-alcoholic fatty liver disease patients from a control group. METHODS: One hundred sixteen non-alcoholic fatty liver disease patients were studied, diagnosed by clinical, biochemical, and liver image or biopsy criteria, and 88 healthy individuals, without any liver disease and testing for oral glucose tolerance within normality. These groups did not differ in age and gender. All were submitted to oral glucose tolerance test and blood samples were collected for glucose and insulin measurements by immunofluorometric method. HOMA-IR was calculated according to the formula: fasting insulin (µU/L x fasting glucose (nmol/L/22.5. RESULTS: NAFLD patients showed higher insulin, glycemia, and HOMA-IR values than control group, even when excluding glucose intolerant and diabetes mellitus patients by their glycemic curves. HOMA-IR 75th percentile for control group was 1.78 and the best area under the curve index was obtained for HOMA-IR values of 2.0 [AUC= 0.840 (0.781-0.899 CI 95%, sensitivity (Se: 85%, specificity (Sp: 83%] while value 2.5 showed best specificity without important loss in sensitivity [AUC=0,831 (0.773-0.888 Se = 72%, Sp = 94%]. CONCLUSION: HOMA-IR values above or equal to 2.0 or 2.5 show enhanced diagnostic value in distinguishing non-alcoholic fatty liver disease carriers from control group individuals.CONTEXTO: Pela sua boa correlação com o "clamp" glicêmico, o HOMA-IR tem sido largamente utilizado como índice de resistência insulínica em estudos clínicos e epidemiológicos em pacientes com doença hepática gordurosa não-alcoólica. Porém os valores utilizados para

  10. The Development and Application of Simulative Insulation Resistance Tester

    Science.gov (United States)

    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.

  11. Insulation Resistance Degradation in Ni-BaTiO3 Multilayer Ceramic Capacitors

    Science.gov (United States)

    Liu, Donhang (David)

    2015-01-01

    Insulation resistance (IR) degradation in Ni-BaTiO3 multilayer ceramic capacitors has been characterized by the measurement of both time to failure and direct-current (DC) leakage current as a function of stress time under highly accelerated life test conditions. The measured leakage current-time dependence data fit well to an exponential form, and a characteristic growth time ?SD can be determined. A greater value of tau(sub SD) represents a slower IR degradation process. Oxygen vacancy migration and localization at the grain boundary region results in the reduction of the Schottky barrier height and has been found to be the main reason for IR degradation in Ni-BaTiO3 capacitors. The reduction of barrier height as a function of time follows an exponential relation of phi (??)=phi (0)e(exp -2?t), where the degradation rate constant ??=??o??(????/????) is inversely proportional to the mean time to failure (MTTF) and can be determined using an Arrhenius plot. For oxygen vacancy electromigration, a lower barrier height phi(0) will favor a slow IR degradation process, but a lower phi(0) will also promote electronic carrier conduction across the barrier and decrease the insulation resistance. As a result, a moderate barrier height phi(0) (and therefore a moderate IR value) with a longer MTTF (smaller degradation rate constant ??) will result in a minimized IR degradation process and the most improved reliability in Ni-BaTiO3 multilayer ceramic capacitors.

  12. Heat resistance insulation for NPP pipelines and components

    International Nuclear Information System (INIS)

    Yurchenko, V.G.; Nazarova, G.A.; Popov, A.M.; Matveeva, N.F.

    1986-01-01

    To insulate hot surfaces of NPP process equipment and pipes it is suggested to use heat resistant insulation of foam aminoimides (FAI). Relative toxicity of aceton and acetaldehyd evolved from FAI in the process of thermal and thermal-oxidative break-down was determined. FAI can be used at 200 deg C

  13. Absorption Voltages and Insulation Resistance in Ceramic Capacitors with Cracks

    Science.gov (United States)

    Teverovsky, Alexander

    2016-01-01

    Time dependence of absorption voltages (Vabs) in different types of low-voltage X5R and X7R ceramic capacitors was monitored for a maximum duration of hundred hours after polarization. To evaluate the effect of mechanical defects on Vabs, cracks in the dielectric were introduced either mechanically or by thermal shock. The maximum absorption voltage, time to roll-off, and the rate of voltage decrease are shown to depend on the crack-related leakage currents and insulation resistance in the parts. A simple model that is based on the Dow equivalent circuit for capacitors with absorption has been developed to assess the insulation resistance of capacitors. Standard measurements of the insulation resistance, contrary to the measurements based on Vabs, are not sensitive to the presence of mechanical defects and fail to reveal capacitors with cracks. Index Terms: Ceramic capacitor, insulation resistance, dielectric absorption, cracking.

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  15. Insulation Resistance and Leakage Currents in Low-Voltage Ceramic Capacitors with Cracks

    Science.gov (United States)

    Teverovsky, Alexander A.

    2016-01-01

    Measurement of insulation resistance (IR) in multilayer ceramic capacitors (MLCCs) is considered a screening technique that ensures the dielectric is defect-free. This work analyzes the effectiveness of this technique for revealing cracks in ceramic capacitors. It is shown that absorption currents prevail over the intrinsic leakage currents during standard IR measurements at room temperature. Absorption currents, and consequently IR, have a weak temperature dependence, increase linearly with voltage (before saturation), and are not sensitive to the presence of mechanical defects. In contrary, intrinsic leakage currents increase super-linearly with voltage and exponentially with temperature (activation energy is in the range from 0.6 eV to 1.1 eV). Leakage currents associated with the presence of cracks have a weaker dependence on temperature and voltage compared to the intrinsic leakage currents. For this reason, intrinsic leakage currents prevail at high temperatures and voltages, thus masking the presence of defects.

  16. CERTIFICATION OF THE RADIATION RESISTANCE OF COIL INSULATION MATERIAL

    CERN Document Server

    Polinski, J; Bogdan, P

    2013-01-01

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

  17. Development of flame retardant, radiation resistant insulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, M.

    1984-01-01

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

  18. Ceramic capacitor insulation resistance failures accelerated by low voltage

    Science.gov (United States)

    Brennan, T. F.

    1978-01-01

    Ceramic capacitors failed insulation resistance testing at less than one-tenth their rated voltage. Many failures recovered as the voltage was increased. Comprehensive failure analysis techniques, some of which are unprecedented, were used to examine these failures. It was determined that there was more than one failure mechanism, and the results indicate a need for special additional screening.

  19. Two-magnon scattering in spin–orbital Mott insulator Ba2IrO4

    International Nuclear Information System (INIS)

    Tsuda, Shunsuke; Uji, Shinya; Okabe, Hirotaka; Isobe, Masaaki

    2016-01-01

    A spin–orbit induced Mott insulator Ba 2 IrO 4 with the pseudo-spin J eff = 1/2, showing an antiferromagnetic order (T N = 240 K), has been investigated by Raman spectroscopy. A broad peak with the B 1g symmetry is found in a wide temperature region up to 400 K, which is ascribed to the two-magnon scattering. From the peak position and width, the exchange coupling and the antiferromagnetic correlation length are estimated to be 590 cm −1 and 45 Å at 90 K, respectively. The results are compared with the antiferromagnet La 2 CuO 4 with the spin S = 1/2. We conclude that there is no significant difference in the short wavelength spin-excitation between the S = 1/2 and J eff = 1/2 systems. (author)

  20. Two-Magnon Scattering in Spin-Orbital Mott Insulator Ba2IrO4

    Science.gov (United States)

    Tsuda, Shunsuke; Okabe, Hirotaka; Isobe, Masaaki; Uji, Shinya

    2016-02-01

    A spin-orbit induced Mott insulator Ba2IrO4 with the pseudo-spin Jeff = 1/2, showing an antiferromagnetic order (TN = 240 K), has been investigated by Raman spectroscopy. A broad peak with the B1g symmetry is found in a wide temperature region up to 400 K, which is ascribed to the two-magnon scattering. From the peak position and width, the exchange coupling and the antiferromagnetic correlation length are estimated to be 590 cm-1 and 45 Å at 90 K, respectively. The results are compared with the antiferromagnet La2CuO4 with the spin S = 1/2. We conclude that there is no significant difference in the short wavelength spin-excitation between the S = 1/2 and Jeff = 1/2 systems.

  1. Effect of radiation resistance additives for insulation materials

    International Nuclear Information System (INIS)

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

    1988-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-01

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

  3. Optical Response of Cu1-xZnxIr2S4 Due to Metal--Insulator Transition

    International Nuclear Information System (INIS)

    Chen, L.; Matsunami, M.; Nanba, T.; Cao, G.; Suzuki, H.; Isobe, M.; Matsumoto, T.

    2003-01-01

    The mother material CuIr 2 S 4 of the thiospinel system Cu 1-x Zn x Ir 2 S 4 undergoes a temperature-induced metal--insulator (Mi) transition. We report the temperature dependence of the optical reflection spectra of Cu 1-x Zn x Ir 2 S 4 (x ≤ 0.5) at the temperatures of 8-300 K in the energy regions of 0.005--30 eV in order to study the change in the electronic structure due to the Zn substitution for Cu. Zn substitution induced mainly the splitting of the hybridization band between the Ir-5d(t 2g ) and S-3 p states crossing the E F . Obtained optical conductivity (σ ) spectrum is discussed in relation to the change in the electronic structure close to the E F . (author)

  4. Magnetic Excitations across the Metal-Insulator Transition in the Pyrochlore Iridate Eu2Ir2O7

    Science.gov (United States)

    Chun, Sae Hwan; Yuan, Bo; Casa, Diego; Kim, Jungho; Kim, Chang-Yong; Tian, Zhaoming; Qiu, Yang; Nakatsuji, Satoru; Kim, Young-June

    2018-04-01

    We report a resonant inelastic x-ray scattering study of the magnetic excitation spectrum in a highly insulating Eu2 Ir2 O7 single crystal that exhibits a metal-insulator transition at TMI=111 (7 ) K . A propagating magnon mode with a 20 meV bandwidth and a 28 meV magnon gap is found in the excitation spectrum at 7 K, which is expected in the all-in-all-out magnetically ordered state. This magnetic excitation exhibits substantial softening as the temperature is raised towards TMI and turns into a highly damped excitation in the paramagnetic phase. Remarkably, the softening occurs throughout the whole Brillouin zone including the zone boundary. This observation is inconsistent with the magnon renormalization expected in a local moment system and indicates that the strength of the electron correlation in Eu2 Ir2 O7 is only moderate, so that electron itinerancy should be taken into account in describing its magnetism.

  5. Mouse-resistant insulated covers keep pipes from freezing

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-01-15

    Fabric wellhead covers and insulated blankets are commonly used at well sites in the Wyoming coalbed methane field to keep surface pipes from freezing. These materials are often chewed up by mice who build nests close to the warm pipes. The mice attract rattlesnakes, a potentially serious problem for the workmen who check the wells daily. Kennon Products of Sheridan, Wyoming solved this problem by making a flexible covering material that has a coating of hardened guard plates that prevents mice from chewing through it. More than a hundred of Kennon's mouse-resistant wellhead covers have been used successfully in the gas fields for over a year. They can be installed in less than 30 minutes and cost only a fraction of what a fiberglass hut costs to purchase and install. Huts are being discouraged for use on federal lands because they alter the nesting patterns of eagles, who perch upon them to hunt rodents. Huts also trap methane gas, which is a potential safety hazard. Kennon's mouse-resistant wellhead covers are lower than the fiberglass huts and blend into the landscape. The company is working on camouflage colours to make wellheads less noticeable. In the future, the company plans to insulate water pipes. 1 fig.

  6. HOMA1-IR and HOMA2-IR indexes in identifying insulin resistance and metabolic syndrome: Brazilian Metabolic Syndrome Study (BRAMS).

    Science.gov (United States)

    Geloneze, Bruno; Vasques, Ana Carolina Junqueira; Stabe, Christiane França Camargo; Pareja, José Carlos; Rosado, Lina Enriqueta Frandsen Paez de Lima; Queiroz, Elaine Cristina de; Tambascia, Marcos Antonio

    2009-03-01

    To investigate cut-off values for HOMA1-IR and HOMA2-IR to identify insulin resistance (IR) and metabolic syndrome (MS), and to assess the association of the indexes with components of the MS. Nondiabetic subjects from the Brazilian Metabolic Syndrome Study were studied (n = 1,203, 18 to 78 years). The cut-off values for IR were determined from the 90th percentile in the healthy group (n = 297) and, for MS, a ROC curve was generated for the total sample. In the healthy group, HOMA-IR indexes were associated with central obesity, triglycerides and total cholesterol (p 2.7 and HOMA2-IR > 1.8; and, for MS were: HOMA1-IR > 2.3 (sensitivity: 76.8%; specificity: 66.7%) and HOMA2-IR > 1.4 (sensitivity: 79.2%; specificity: 61.2%). The cut-off values identified for HOMA1-IR and HOMA2-IR indexes have a clinical and epidemiological application for identifying IR and MS in Westernized admixtured multi-ethnic populations.

  7. High temperature resistant cermet and ceramic compositions. [for thermal resistant insulators and refractory coatings

    Science.gov (United States)

    Phillips, W. M. (Inventor)

    1978-01-01

    High temperature oxidation resistance, high hardness and high abrasion and wear resistance are properties of cermet compositions particularly to provide high temperature resistant refractory coatings on metal substrates, for use as electrical insulation seals for thermionic converters. The compositions comprise a sintered body of particles of a high temperature resistant metal or metal alloy, preferably molybdenum or tungsten particles, dispersed in and bonded to a solid solution formed of aluminum oxide and silicon nitride, and particularly a ternary solid solution formed of a mixture of aluminum oxide, silicon nitride and aluminum nitride. Ceramic compositions comprising a sintered solid solution of aluminum oxide, silicon nitride and aluminum nitride are also described.

  8. HOMA1-IR and HOMA2-IR indexes in identifying insulin resistance and metabolic syndrome - Brazilian Metabolic Syndrome Study (BRAMS)

    OpenAIRE

    Geloneze, B; Vasques, ACJ; Stabe, CFC; Pareja, JC; Rosado, LEFPD; de Queiroz, EC; Tambascia, MA

    2009-01-01

    Objective: To investigate cut-off values for HOMA1-IR and HOMA2-IR to identify insulin resistance (IR) and metabolic syndrome (MS), and to assess the association of the indexes with components of the MS. Methods: Nondiabetic subjects from the Brazilian Metabolic Syndrome Study were studied (n = 1,203, 18 to 78 years). The cut-off values for IR were determined from the 9011 percentile in the healthy group (n = 297) and, for MS, a ROC curve was generated for the total sample. Results: In the he...

  9. Direct Observation of Surface Potential Distribution in Insulation Resistance Degraded Acceptor-Doped BaTiO3 Multilayered Ceramic Capacitors

    Science.gov (United States)

    Hong, Kootak; Lee, Tae Hyung; Suh, Jun Min; Park, Jae-Sung; Kwon, Hyung-Soon; Choi, Jaeho; Jang, Ho Won

    2018-05-01

    Insulation resistance (IR) degradation in BaTiO3 is a key issue for developing miniaturized multilayer ceramic capacitors (MLCCs) with high capacity. Despite rapid progress in BaTiO3-based MLCCs, the mechanism of IR degradation is still controversial. In this study, we demonstrate the Al doping effect on IR degradation behavior of BaTiO3 MLCCs by electrical measurements and scanning Kelvin probe microscopy (SKPM). As the Al doping concentration in BaTiO3 increases, IR degradation of MLCCs seems to be suppressed from electrical characterization results. However, SKPM results reveal that the conductive regions near the cathode become lager with Al doping after IR degradation. The formation of conducting regions is attributed to the migration of oxygen vacancies, which is the origin of IR degradation in BaTiO3, in dielectric layers. These results imply that acceptor doping in BaTiO3 solely cannot suppress the IR degradation in MLCC even though less asymmetric IR characteristics and IR degradation in MLCCs with higher Al doping concentration are observed from electrical characterization. Our results strongly suggest that observing the surface potential distribution in IR degraded dielectric layers using SKPM is an effective method to unravel the mechanism of IR degradation in MLCCs.

  10. Improvements to the electrical insulation resistance of high quality magnesia insulated cables

    International Nuclear Information System (INIS)

    Mauger, R.A.; Goodings, A.

    1984-03-01

    Mineral insulated signal cables for nuclear reactor instrumentation schemes have to meet stringent electrical insulation requirements at high temperatures. This report discusses the factors which influence the attainment of this objective and the way in which it has been reached under industrial manufacturing conditions. It emphasises the importance of moisture and gives details of the improvements achieved as a result of moisture reduction. (author)

  11. Wall Thickness Measurement Of Insulated Pipe By Tangential Radiography Technique Using Ir 192

    International Nuclear Information System (INIS)

    Soedarjo

    2000-01-01

    Insulation pipe wall thickness by tangential radiography technique has been carried out using 41 Curie Iridium 192 source has activity for two carbon steel pipes. The outer diameter of the first pipe is 90 mm, wall thickness is 75.0 mm, source film film distance is 609.5 mm, source tangential point of insulation is 489.5 mm and exposure time 3 minute and 25 second. From the calculation, the first pipe thickness is found to be 12.54 mm and for the second pipe is 8.42 mm. The thickness is due to inaccuracy in reading the pipe thickness on radiography film and the geometry distortion radiation path

  12. Radiaton-resistant electrical insulation on the base of cement binders

    International Nuclear Information System (INIS)

    Afanas'ev, V.V.; Korenevskij, V.V.; Pisachev, S.Yu.

    1985-01-01

    The problems of designing radiation-resistant electrical insulations on the base of BATs and Talum cements for the UNK magnets operating under constant and pulse modes are discussed. The data characterizing dielectrical ad physico-mechanical properties of 25 various compositions are given. Two variants of manufacturing coils are considered: solid and with the use of asbestos tape impregnated with aluminous cement solution. The data obtained testify to the fact that the advantages of insulation on Talum cement are raised radiation resistance, high strength (particularly compression strength), weak porosity, high elasticity modulus and high thermal conductivity. BATs cement insulation is characterized by high radiation resistance, absence of shrinkage, rather low elasticity modulus and high dielectrical characteristics under normal conditions. The qualities of the solid insulation variant are its high technological effectiveness and posibility to fill up the spaces of complex configuration. In case of using as solid insulation Talum cement, however special measures for moisture removal are required. The advantage of insulation on the base of the asbestos tape is its reliability. For complex configuration magnets, however to realize is such insulation somewhat difficult

  13. [Reliability of HOMA-IR for evaluation of insulin resistance during perioperative period].

    Science.gov (United States)

    Fujino, Hiroko; Itoda, Shoko; Sako, Saori; Matsuo, Kazuki; Sakamoto, Eiji; Yokoyama, Takeshi

    2013-02-01

    Hyperglycemia due to increase in insulin resistance (IR) is often observed after surgery in spite of normal insulin secretion. To evaluate the degree of IR, the golden standard method is the normoglycemic hyperinsulinemic clamp technique (glucose clamp: GC). The GC using the artificial pancreas, STG-22 (Nikkiso, Tokyo, Japan), was established as a more reliable method, since it was evaluated during steady-state period under constant insulin infusion. Homeostasis model assessment insulin resistance (HOMA-IR), however, is frequently employed in daily practice because of its convenience. We, therefore, investigated the reliability of HOMA-IR in comparison with the glucose clamp using the STG-22. Eight healthy patients undergoing maxillofacial surgery were employed in this study after obtaining written informed consent. Their insulin resistance was evaluated by HOMA-IR and the GC using the STG-22 before and after surgery. HOMA-IR increased from 0.81 +/- 0.48 to 1.17 +/- 0.50, although there were no significant differences between before and after surgery. On the other hand, M-value by GC significantly decreased after surgery from 8.82 +/- 2.49 mg x kg(-1) x min(-1) to 3.84 +/- 0.79 mg x kg(-1) x min(-1) (P = 0.0003). In addition, no significant correlation was found between the values of HOMA-IR and the M-value by GC. HOMA-IR may not be reliable to evaluate IR for perioperative period.

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  15. Bipolar resistive switching in metal-insulator-semiconductor nanostructures based on silicon nitride and silicon oxide

    Science.gov (United States)

    Koryazhkina, M. N.; Tikhov, S. V.; Mikhaylov, A. N.; Belov, A. I.; Korolev, D. S.; Antonov, I. N.; Karzanov, V. V.; Gorshkov, O. N.; Tetelbaum, D. I.; Karakolis, P.; Dimitrakis, P.

    2018-03-01

    Bipolar resistive switching in metal-insulator-semiconductor (MIS) capacitor-like structures with an inert Au top electrode and a Si3N4 insulator nanolayer (6 nm thick) has been observed. The effect of a highly doped n +-Si substrate and a SiO2 interlayer (2 nm) is revealed in the changes in the semiconductor space charge region and small-signal parameters of parallel and serial equivalent circuit models measured in the high- and low-resistive capacitor states, as well as under laser illumination. The increase in conductivity of the semiconductor capacitor plate significantly reduces the charging and discharging times of capacitor-like structures.

  16. 49 CFR 236.552 - Insulation resistance; requirement.

    Science.gov (United States)

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION... resistance between wiring and ground of continuous inductive automatic cab signal system, automatic train...

  17. IR transmittance of moisture-resistant germanate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Bocharova, T.V.; Karapetyan, G.O. [St. Petersburg State Technical Univ. (Russian Federation)

    1995-05-01

    The objective of this work was to study the infrared spectra of gallogermante glasses and develop methods of improving their moisture resistance while retaining transparency. The ion exchange properties had been previously investigated.

  18. Fibers and fabrics with insulating, water-proofing, and flame-resistant properties

    Science.gov (United States)

    Hrubesh, Lawrence W.; Poco, John F.; Coronado, Paul R.

    2004-04-20

    Fibers, and fabrics produced from the fibers, are made water repellent, fire-retardant and/or thermally insulating by filling void spaces in the fibers and/or fabrics with a powdered material. When the powder is sufficiently finely divided, it clings tenaciously to the fabric's fibers and to itself, resisting the tendency to be removed from the fabric.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-04-01

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

  20. Radiation resistance of insulating materials for electric wires

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  1. IRS-1 serine phosphorylation and insulin resistance in skeletal muscle from pancreas tranplant recipient

    DEFF Research Database (Denmark)

    Bouzakri, K; Karlsson, HRK; Vestergaard, Henrik

    2006-01-01

    Insulin-dependent diabetic recipients of successful pancreas allografts achieve self-regulatory insulin secretion and discontinue exogenous insulin therapy; however, chronic hyperinsulinemia and impaired insulin sensitivity generally develop. To determine whether insulin resistance is accompanied....... In conclusion, peripheral insulin resistance in pancreas-kidney transplant recipients may arise from a negative feedback regulation of the canonical insulin-signaling cascade from excessive serine phosphorylation of IRS-1, possibly as a consequence of immunosuppressive therapy and hyperinsulinemia....... insulin receptor substrate (IRS)-1 Ser (312) and Ser (616) phosphorylation, IRS-1-associated phosphatidylinositol 3-kinase activity, and extracellular signal-regulated kinase (ERK)-1/2 phosphorylation were elevated in pancreas-kidney transplant recipients, coincident with fasting hyperinsulinemia. Basal...

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

    DEFF Research Database (Denmark)

    Yang, Zhenyu; Wang, Qian

    2011-01-01

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

  3. Observation of a Slater-type metal-to-insulator transition in Sr$_2$IrO$_4$ from time-resolved photo-carrier dynamics

    OpenAIRE

    Hsieh, D.; Mahmood, F.; Torchinsky, D. H.; Cao, G.; Gedik, N.

    2012-01-01

    We perform a time-resolved optical study of Sr$_2$IrO$_4$ to understand the influence of magnetic ordering on the low energy electronic structure of a strongly spin-orbit coupled $J_{eff}$=1/2 Mott insulator. By studying the recovery dynamics of photo-carriers excited across the Mott gap, we find that upon cooling through the N\\'{e}el temperature $T_N$ the system evolves continuously from a metal-like phase with fast ($\\sim$50 fs) and excitation density independent relaxation dynamics to a ga...

  4. Resistência insulínica pode prejudicar a redução da espessura mediointimal em adolescentes obesos Insulin resistance can impair reduction on carotid intima-media thickness in obese adolescents

    Directory of Open Access Journals (Sweden)

    Priscila de Lima Sanches

    2012-10-01

    Full Text Available FUNDAMENTO: O processo aterosclerótico no nível endotelial começa em idade precoce e parece estar associado com a obesidade e suas comorbidades como a resistência insulínica. OBJETIVO: O objetivo deste estudo foi verificar a influência da resistência insulínica em marcadores inflamatórios e subclínicos de aterosclerose em adolescentes obesos. MÉTODOS: Sessenta e seis adolescentes obesos pós-púberes foram divididos em dois grupos de acordo com o índice de resistência insulínica estimado pelo Modelo de Avaliação da Homeostase (HOMA-RI: com resistência insulínica (RI n = 39 e sem resistência insulínica (NRI n = 27, e foram submetidos a uma intervenção interdisciplinar ao longo de um ano. A espessura mediointimal da artéria carótida comum (EMIC, e o tecido adiposo visceral e subcutâneo foram determinados por ultrassonografia. A composição corporal, pressão arterial, índice HOMA-RI, perfil lipídico e as concentrações de adipocinas [leptina, adiponectina, e inibidor do ativador do plasminogênio-1 (PAI-1] foram analisados antes e após a terapia. RESULTADOS: Ambos os grupos apresentaram melhoras significativas na composição corporal, estado inflamatório (redução da concentração de leptina e PAI 1; aumento de adiponectina plasmática e redução da EMIC. Apenas o grupo NRI mostrou correlação positiva entre as alterações na gordura visceral (∆Visceral e mudanças na EMIC (∆ EMIC (r = 0,42, p BACKGROUND: The atherosclerotic process at the endothelial level begins in early ages and seems to be associated with obesity and its comorbidities as insulin resistance. OBJECTIVE: The aim of this study was to verify the influence of insulin resistance on inflammatory and subclinical markers of atherosclerosis in obese adolescents. METHODS: Sixty-six post-pubescent obese adolescents were divided in two groups according to homeostasis model assessment of insulin resistance (HOMA-IR measurement: with insulin resistance

  5. Genetic variant near IRS1 is associated with type 2 diabetes, insulin resistance and hyperinsulinemia

    DEFF Research Database (Denmark)

    Rung, Johan; Cauchi, Stéphane; Albrechtsen, Anders

    2009-01-01

    sample of 4,977 French individuals. We then selected the 28 best hits for replication in 7,698 Danish subjects and identified 4 SNPs showing strong association with T2D, one of which (rs2943641, P = 9.3 x 10(-12), OR = 1.19) was located adjacent to the insulin receptor substrate 1 gene (IRS1). Unlike...... previously reported T2D risk loci, which predominantly associate with impaired beta cell function, the C allele of rs2943641 was associated with insulin resistance and hyperinsulinemia in 14,358 French, Danish and Finnish participants from population-based cohorts; this allele was also associated...... with reduced basal levels of IRS1 protein and decreased insulin induction of IRS1-associated phosphatidylinositol-3-OH kinase activity in human skeletal muscle biopsies....

  6. Highly radiation-resistant vacuum impregnation resin systems for fusion magnet insulation

    International Nuclear Information System (INIS)

    Fabian, P.E.; Munshi, N.A.; Denis, R.J.

    2002-01-01

    Magnets built for fusion devices such as the newly proposed Fusion Ignition Research Experiment (FIRE) need to be highly reliable, especially in a high radiation environment. Insulation materials are often the weak link in the design of superconducting magnets due to their sensitivity to high radiation doses, embrittlement at cryogenic temperatures, and the limitations on their fabricability. An insulation system capable of being vacuum impregnated with desirable properties such as a long pot-life, high strength, and excellent electrical integrity and which also provides high resistance to radiation would greatly improve magnet performance and reduce the manufacturing costs. A new class of insulation materials has been developed utilizing cyanate ester chemistries combined with other known radiation-resistant resins, such as bismaleimides and polyimides. These materials have been shown to meet the demanding requirements of the next generation of devices, such as FIRE. Post-irradiation testing to levels that exceed those required for FIRE showed no degradation in mechanical properties. In addition, the cyanate ester-based systems showed excellent performance at cryogenic temperatures and possess a wide range of processing variables, which will enable cost-effective fabrication of new magnets. This paper details the processing parameters, mechanical properties at 76 K and 4 K, as well as post-irradiation testing to dose levels surpassing 10 8 Gy

  7. Resistivity and magnetoresistance studies of Nb3Ir and V3Sb compounds

    International Nuclear Information System (INIS)

    Ghosh, M.; Barman, A.; Das, A.; Meikap, A.K.; De, S.K.; Chatterjee, S.

    1997-01-01

    We have performed measurements of electrical resistivity and magnetoresistivity of the compounds Nb 3 Ir and V 3 Sb in the temperature range 1.8 K ≤ T ≤ 300 K in absence as well as in presence of a magnetic field up to 7.7 T. At high temperature the resistivity shows a linear behaviour whereas the low temperature resistivity shows a T 2 behaviour. The data are fitted to several theories in order to explain the anomalous behaviour of the resistivity. The simple s-d scattering model is not adequate to offer a proper explanation for the positive magnetoresistance. The enhancement of the coefficient A of the T 2 term and the deviation from the quadratic field dependence of the resistivity may be due to the anisotropy in the compounds. (orig.)

  8. Negative differential resistance in the Peierls insulating phases of TTF-TCNQ

    Science.gov (United States)

    Tonouchi, Daiki; Matsushita, Michio M.; Awaga, Kunio

    2017-07-01

    Negative differential resistance (NDR) was observed in the most well known organic conductor, TTF-TCNQ, in its low-temperature Peierls insulator phase below 53 K. The voltage-current (V -I ) characteristics below this temperature, measured by a four-probe method, exhibited unique NDR behavior, in which the d V /d I versus conductivity (σ) plots had the inflection points at the three σ values without depending on temperature. These σ values were found to coincide with the conductivities at the three transition temperatures (53, 49, and 38 K) for the formation of the charge-density waves in TTF-TCNQ. This suggests that the electronic structure of the Peierls insulating phase of TTF-TCNQ is governed by the total carrier density, which is determined by not only thermal excitation but also carrier injection.

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

    International Nuclear Information System (INIS)

    Wu, Y S; Fan, Jintu

    2009-01-01

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

  10. Homa1-ir And Homa2-ir Indexes In Identifying Insulin Resistance And Metabolic Syndrome - Brazilian Metabolic Syndrome Study (brams) [Índices Homa1-ir E Homa2-ir Para Identificação De Resistência à Insulina E Síndrome Metabólica - Estudo Brasileiro De Síndrome Metabólica (brams)

    OpenAIRE

    Geloneze B.; Vasques A.C.J.; Stabe C.F.C.; Pareja J.C.; de Lima Rosado L.E.F.P.; de Queiroz E.C.; Tambascia M.A.

    2009-01-01

    Objective: To investigate cut-off values for HOMA1-IR and HOMA2-IR to identify insulin resistance (IR) and metabolic syndrome (MS), and to assess the association of the indexes with components of the MS. Methods: Nondiabetic subjects from the Brazilian Metabolic Syndrome Study were studied (n = 1,203, 18 to 78 years). The cut-off values for IR were determined from the 90th percentile in the healthy group (n = 297) and, for MS, a ROC curve was generated for the total sample. Results: In the he...

  11. Peroxynitrite mediates muscle insulin resistance in mice via nitration of IRβ/IRS-1 and Akt

    International Nuclear Information System (INIS)

    Zhou Jun; Huang Kaixun

    2009-01-01

    Accumulating evidence suggests that peroxynitrite (ONOO - ) is involved in the pathogenesis of insulin resistance. In the current study, we investigated whether insulin resistance in vivo could be mediated by nitration of proteins involved in the early steps of the insulin signal transduction pathway. Exogenous peroxynitrite donated by 3-morpholinosydnonimine hydrochloride (SIN-1) induced in vivo nitration of the insulin receptor β subunit (IRβ), insulin receptor substrate (IRS)-1, and protein kinase B/Akt (Akt) in skeletal muscle of mice and dramatically reduced whole-body insulin sensitivity and muscle insulin signaling. Moreover, in high-fat diet (HFD)-fed insulin-resistant mice, we observed enhanced nitration of IRβ and IRS-1 in skeletal muscle, in parallel with impaired whole-body insulin sensitivity and muscle insulin signaling. Reversal of nitration of these proteins by treatment with the peroxynitrite decomposition catalyst FeTPPS yielded an improvement in whole-body insulin sensitivity and muscle insulin signaling in HFD-fed mice. Taken together, these findings provide new mechanistic insights for the involvement of peroxynitrite in the development of insulin resistance and suggest that nitration of proteins involved in the early steps of insulin signal transduction is a novel molecular mechanism of HFD-induced muscle insulin resistance.

  12. Non-volatile resistive switching in the Mott insulator (V1-xCrx)2O3

    Science.gov (United States)

    Querré, M.; Tranchant, J.; Corraze, B.; Cordier, S.; Bouquet, V.; Députier, S.; Guilloux-Viry, M.; Besland, M.-P.; Janod, E.; Cario, L.

    2018-05-01

    The discovery of non-volatile resistive switching in Mott insulators related to an electric-field-induced insulator to metal transition (IMT) has paved the way for their use in a new type of non-volatile memories, the Mott memories. While most of the previous studies were dedicated to uncover the resistive switching mechanism and explore the memory potential of chalcogenide Mott insulators, we present here a comprehensive study of resistive switching in the canonical oxide Mott insulator (V1-xCrx)2O3. Our work demonstrates that this compound undergoes a non-volatile resistive switching under electric field. This resistive switching is induced by a Mott transition at the local scale which creates metallic domains closely related to existing phases of the temperature-pressure phase diagram of (V1-xCrx)2O3. Our work demonstrates also reversible resistive switching in (V1-xCrx)2O3 crystals and thin film devices. Preliminary performances obtained on 880 nm thick layers with 500 nm electrodes show the strong potential of Mott memories based on the Mott insulator (V1-xCrx)2O3.

  13. 49 CFR 178.358 - Specification 21PF fire and shock resistant, phenolic-foam insulated, metal overpack.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Specification 21PF fire and shock resistant, phenolic-foam insulated, metal overpack. 178.358 Section 178.358 Transportation Other Regulations Relating... Class 7 (Radioactive) Materials § 178.358 Specification 21PF fire and shock resistant, phenolic-foam...

  14. Homeostatic model assessment for insulin resistance (homa-ir): a better marker for evaluating insulin resistance than fasting insulin in women with polycystic ovarian syndrome

    International Nuclear Information System (INIS)

    Majid, H.; Khan, A.H.; Masood, Q.

    2017-01-01

    To assess the utility of HOMA-IR in assessing insulin resistance in patients with polycystic ovary syndrome (PCOS) and compare it with fasting insulin for assessing insulin resistance (IR). Study Design: Observational study. Place and Duration of Study: Section of Clinical Chemistry, Department of Pathology and Laboratory Medicine, The Aga Khan University Hospital, Karachi, from January 2009 to September 2012. Methodology: Medical chart review of all women diagnosed with PCOS was performed. Of the 400 PCOS women reviewed, 91 met the inclusion criteria. Insulin resistance was assessed by calculating HOMA-IR using the formula (fasting glucose x fasting insulin)/405, taking normal value =12 micro IU/ml. Results: A total of 91 premenopausal women diagnosed with PCOS were included. Mean age was 30 +-5.5 years. Mean HOMA-IR of women was 3.1 +-1.7, respectively with IR in 69% (n=63) women, while hyperinsulinemia was present in 60% (n=55) women (fasting Insulin 18.5 +-5.8 micro IU/ml). Hyperandrogenism was present in 53.8% (n=49), whereas 38.5% (n=35) women had primary infertility or subfertility, while 65.9% (n=60) had menstrual irregularities; and higher frequencies were observed in women with IR. Eight subjects with IR and endocrine abnormalities were missed by fasting insulin. Conclusion: Insulin resistance is common in PCOS and it is likely a pathogenic factor for development of PCOS. HOMA-IR model performed better than hyperinsulinemia alone for diagnosing IR. (author)

  15. Homeostatic Model Assessment-Insulin Resistance (HOMA-IR 2) in Mild Subclinical Hypothyroid Subjects.

    Science.gov (United States)

    Sengupta, Shreejita; Jaseem, T; Ambalavanan, Jayachidambaram; Hegde, Anupama

    2018-04-01

    Despite various studies with conflicting results, the effect of thyroid hormones on lipids and insulin levels in dysthyroidism is of great interest. This case control study was aimed to perceive the existence of IR and dyslipidemia in mild subclinical hypothyroid subjects (TSH ≤ 9.9 µIU/ml) as compared to their age and gender matched euthyroid controls. Basic demographic information like height, weight was recorded. Serum samples of all the subjects were assayed for thyroid profile, lipid profile, blood glucose, HbA1C and insulin. BMI and insulin resistance was calculated. Compared to controls patients with mild subclinical hypothyroidism demonstrated hyperinsulinemia and dyslipidemia observed by the higher LDL cholesterol. A significantly positive correlation was observed for HOMA-IR with TSH and LDL cholesterol. Hence, even in the mild subclinical hypothyroid state assessment of thyroid function should be combined with estimation of plasma glucose, insulin and serum lipids to monitor and prevent its associated effects.

  16. IRS-1 serine phosphorylation and insulin resistance in skeletal muscle from pancreas tranplant recipient

    DEFF Research Database (Denmark)

    Bouzakri, K; Karlsson, HRK; Vestergaard, Henrik

    2006-01-01

    Insulin-dependent diabetic recipients of successful pancreas allografts achieve self-regulatory insulin secretion and discontinue exogenous insulin therapy; however, chronic hyperinsulinemia and impaired insulin sensitivity generally develop. To determine whether insulin resistance is accompanied...... by altered signal transduction, skeletal muscle biopsies were obtained from pancreas-kidney transplant recipients (n = 4), nondiabetic kidney transplant recipients (receiving the same immunosuppressive drugs; n = 5), and healthy subjects (n = 6) before and during a euglycemic-hyperinsulinemic clamp. Basal...... insulin receptor substrate (IRS)-1 Ser (312) and Ser (616) phosphorylation, IRS-1-associated phosphatidylinositol 3-kinase activity, and extracellular signal-regulated kinase (ERK)-1/2 phosphorylation were elevated in pancreas-kidney transplant recipients, coincident with fasting hyperinsulinemia. Basal...

  17. IRS-1 serine phosphorylation and insulin resistance in skeletal muscle from pancreas transplant recipients

    DEFF Research Database (Denmark)

    Bouzakri, Karim; Karlsson, Håkan K R; Vestergaard, Henrik

    2006-01-01

    Insulin-dependent diabetic recipients of successful pancreas allografts achieve self-regulatory insulin secretion and discontinue exogenous insulin therapy; however, chronic hyperinsulinemia and impaired insulin sensitivity generally develop. To determine whether insulin resistance is accompanied...... by altered signal transduction, skeletal muscle biopsies were obtained from pancreas-kidney transplant recipients (n = 4), nondiabetic kidney transplant recipients (receiving the same immunosuppressive drugs; n = 5), and healthy subjects (n = 6) before and during a euglycemic-hyperinsulinemic clamp. Basal...... insulin receptor substrate (IRS)-1 Ser (312) and Ser (616) phosphorylation, IRS-1-associated phosphatidylinositol 3-kinase activity, and extracellular signal-regulated kinase (ERK)-1/2 phosphorylation were elevated in pancreas-kidney transplant recipients, coincident with fasting hyperinsulinemia. Basal...

  18. Categories and inheritance of resistance to Nilaparvata lugens (Hemiptera: Delphacidae) in mutants of indica rice 'IR64'.

    Science.gov (United States)

    Sangha, Jatinder Singh; Chen, Yolanda H; Palchamy, Kadirvel; Jahn, Gary C; Maheswaran, M; Adalla, Candida B; Leung, Hei

    2008-04-01

    Varietal mutants can be useful for developing durable resistance, understanding categories of resistance, and identifying candidate genes involved in defense responses. We used mutants of rice 'IR64' to isolate new sources of resistance to the planthopper Nilaparvata lugens (Stål) (Hemiptera: Delphacidae). We compared two mutants that showed a gain and loss of resistance to N. lugens, to determine the categories of resistance to this pest. Under choice tests, female planthoppers avoided settling and laid fewer eggs on the resistant mutant 'D518' than on the susceptible mutant D1131, susceptible check 'TN1', and wild-type IR64, indicating that antixenosis was the resistance category. Similarly, under no-choice conditions, planthoppers laid 29% fewer eggs in D518 than in IR64, but they oviposited more in 'D1131' and TN1. Honeydew excretion was greater on D1131 seedlings but slightly lower on D518 than on IR64. Nymphal survival and adult female weight did not differ among rice cultivars. D518 showed higher tolerance of N. lugens infestations than IR64. Genetic analysis of the F1, F2, and F3 populations derived from D518 x IR64 revealed that resistance in D518 is dominant and controlled by a single gene. Despite the variation in resistance to N. lugens, both mutants and IR64 performed similarly in the field. The mutant D518 is a new source of durable resistance to N. lugens, mainly due to enhanced antixenosis to female hoppers for settling and oviposition.

  19. Electric field-triggered metal-insulator transition resistive switching of bilayered multiphasic VOx

    Science.gov (United States)

    Won, Seokjae; Lee, Sang Yeon; Hwang, Jungyeon; Park, Jucheol; Seo, Hyungtak

    2018-01-01

    Electric field-triggered Mott transition of VO2 for next-generation memory devices with sharp and fast resistance-switching response is considered to be ideal but the formation of single-phase VO2 by common deposition techniques is very challenging. Here, VOx films with a VO2-dominant phase for a Mott transition-based metal-insulator transition (MIT) switching device were successfully fabricated by the combined process of RF magnetron sputtering of V metal and subsequent O2 annealing to form. By performing various material characterizations, including scanning transmission electron microscopy-electron energy loss spectroscopy, the film is determined to have a bilayer structure consisting of a VO2-rich bottom layer acting as the Mott transition switching layer and a V2O5/V2O3 mixed top layer acting as a control layer that suppresses any stray leakage current and improves cyclic performance. This bilayer structure enables excellent electric field-triggered Mott transition-based resistive switching of Pt-VOx-Pt metal-insulator-metal devices with a set/reset current ratio reaching 200, set/reset voltage of less than 2.5 V, and very stable DC cyclic switching upto 120 cycles with a great set/reset current and voltage distribution less than 5% of standard deviation at room temperature, which are specifications applicable for neuromorphic or memory device applications. [Figure not available: see fulltext.

  20. Thermal insulation

    International Nuclear Information System (INIS)

    Pinsky, G.P.

    1977-01-01

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

  1. Homeostatic Model Assessment for Insulin Resistance (HOMA-IR): A Better Marker for Evaluating Insulin Resistance Than Fasting Insulin in Women with Polycystic Ovarian Syndrome.

    Science.gov (United States)

    Majid, Hafsa; Masood, Qamar; Khan, Aysha Habib

    2017-03-01

    To assess the utility of HOMA-IR in assessing insulin resistance in patients with polycystic ovary syndrome (PCOS) and compare it with fasting insulin for assessing insulin resistance (IR). Observational study. Section of Clinical Chemistry, Department of Pathology and Laboratory Medicine, The Aga Khan University Hospital, Karachi, from January 2009 to September 2012. Medical chart review of all women diagnosed with PCOS was performed. Of the 400 PCOS women reviewed, 91 met the inclusion criteria. Insulin resistance was assessed by calculating HOMA-IR using the formula (fasting glucose x fasting insulin)/405, taking normal value HOMA-IR of women was 3.1 ±1.7, respectively with IR in 69% (n=63) women, while hyperinsulinemia was present in 60% (n=55) women (fasting Insulin 18.5 ±5.8 µIU/ml). Hyperandrogenism was present in 53.8% (n=49), whereas 38.5% (n=35) women had primary infertility or subfertility, while 65.9% (n=60) had menstrual irregularities; and higher frequencies were observed in women with IR. Eight subjects with IR and endocrine abnormalities were missed by fasting insulin. Insulin resistance is common in PCOS and it is likely a pathogenic factor for development of PCOS. HOMAIR model performed better than hyperinsulinemia alone for diagnosing IR.

  2. Acanthosis nigricans and insulin resistance in overweight children and adolescents Acantose nigricans e resistência insulínica em crianças e adolescentes com excesso de peso

    Directory of Open Access Journals (Sweden)

    Caroline Evelin Nascimento Kluczynik

    2012-08-01

    Full Text Available BACKGROUND: Studies have suggested an association between the presence of acanthosis nigricans (AN and the development of diabetes. OBJECTIVE: To investigate the association between AN and insulin resistance (IR in overweight children and adolescents receiving care at the Center for Childhood Obesity, Campina Grande, PB. METHODS: This cross-sectional study was conducted between April 2009 and April 2010 including 194 individuals of 2 to 18 years of age receiving care within the Brazilian national health network. The presence of acanthosis nigricans was verified and anthropometric measurements were taken. The following tests were performed: insulin, triglycerides, HDL-cholesterol, glucose and homeostasis model of assessment - insulin resistance (HOMA-IR. Statistical analyses were performed using the SPSS software program, version 17.0. RESULTS: There was a greater prevalence of females (66%, brown-skinned individuals (63.4%, adolescents (61.3% and severely obese individuals (66.5%. Acanthosis nigricans was identified in 58.2% and IR in 42.7% of the participants. Acanthosis nigricans was associated with being non-white (p = 0.003, with being an adolescent (p = 0.003 and with IR (p = 0.001. Non-white individuals, adolescents and those with insulin resistance were 5.4, 2.47 and 2.66 times more likely to have acanthosis nigricans, respectively. CONCLUSION: The results of this study indicate a need to train healthcare professionals to identify acanthosis nigricans, since this condition is associated with IR. Identifying acanthosis nigricans in childhood permits the safe and timely treatment of cardiometabolic disorders through careful monitoring and appropriate treatment.FUNDAMENTOS: Estudos sugerem haver associação entre a presença de Acantose Nigricans e o desenvolvimento do diabetes. OBJETIVO: Verificar a associação entre Acantose Nigricans e Resistência Insulínica (RI em crianças e adolescentes com excesso de peso, atendidos no Centro de

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-01-15

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

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

    International Nuclear Information System (INIS)

    Brechna, H.

    1975-01-01

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

  5. The definition of insulin resistance using HOMA-IR for Americans of Mexican descent using machine learning.

    Science.gov (United States)

    Qu, Hui-Qi; Li, Quan; Rentfro, Anne R; Fisher-Hoch, Susan P; McCormick, Joseph B

    2011-01-01

    The lack of standardized reference range for the homeostasis model assessment-estimated insulin resistance (HOMA-IR) index has limited its clinical application. This study defines the reference range of HOMA-IR index in an adult Hispanic population based with machine learning methods. This study investigated a Hispanic population of 1854 adults, randomly selected on the basis of 2000 Census tract data in the city of Brownsville, Cameron County. Machine learning methods, support vector machine (SVM) and Bayesian Logistic Regression (BLR), were used to automatically identify measureable variables using standardized values that correlate with HOMA-IR; K-means clustering was then used to classify the individuals by insulin resistance. Our study showed that the best cutoff of HOMA-IR for identifying those with insulin resistance is 3.80. There are 39.1% individuals in this Hispanic population with HOMA-IR>3.80. Our results are dramatically different using the popular clinical cutoff of 2.60. The high sensitivity and specificity of HOMA-IR>3.80 for insulin resistance provide a critical fundamental for our further efforts to improve the public health of this Hispanic population.

  6. Research into the usage of integrated jamming of IR weakening and smoke-screen resisting the IR imaging guided missiles

    Science.gov (United States)

    Wang, Long-tao; Jiang, Ning; Lv, Ming-shan

    2015-10-01

    With the emergence of the anti-ship missle with the capability of infrared imaging guidance, the traditional single jamming measures, because of the jamming mechanism and technical flaws or unsuitable use, greatly reduced the survival probability of the war-ship in the future naval battle. Intergrated jamming of IR weakening + smoke-screen Can not only make jamming to the search and tracking of IR imaging guidance system , but also has feasibility in conjunction, besides , which also make the best jamming effect. The research conclusion has important realistic meaning for raising the antimissile ability of surface ships. With the development of guidance technology, infrared guidance system has expanded by ir point-source homing guidance to infrared imaging guidance, Infrared imaging guidance has made breakthrough progress, Infrared imaging guidance system can use two-dimensional infrared image information of the target, achieve the precise tracking. Which has Higher guidance precision, better concealment, stronger anti-interference ability and could Target the key parts. The traditional single infrared smoke screen jamming or infrared decoy flare interference cannot be imposed effective interference. So, Research how to effectively fight against infrared imaging guided weapons threat measures and means, improving the surface ship antimissile ability is an urgent need to solve.

  7. Sprayable Aerogel Bead Compositions With High Shear Flow Resistance and High Thermal Insulation Value

    Science.gov (United States)

    Ou, Danny; Trifu, Roxana; Caggiano, Gregory

    2013-01-01

    A sprayable aerogel insulation has been developed that has good mechanical integrity and lower thermal conductivity than incumbent polyurethane spray-on foam insulation, at similar or lower areal densities, to prevent insulation cracking and debonding in an effort to eliminate the generation of inflight debris. This new, lightweight aerogel under bead form can be used as insulation in various thermal management systems that require low mass and volume, such as cryogenic storage tanks, pipelines, space platforms, and launch vehicles.

  8. The relationship between visfatin and HOMA-IR in hypertensive patients, and the effect of antihypertensive drugs on visfatin and HOMA-IR in hypertensive patients with insulin resistance.

    Science.gov (United States)

    Lan, Jianjun; Chen, Xiaoni; Chen, Xiaoping; Wang, Si; Zhang, Xin; Wu, Kai; He, Sen; Peng, Yong; Jiang, Lingyun; Li, Longxin; Wan, Liyan

    2011-10-01

    To investigate the correlation between serum visfatin and insulin resistance (IR) in non-diabetic essential hypertensive (EH) patients with and without IR, and to evaluate the effect of antihypertensive treatment on serum visfatin and IR in these patients. A total of 81 non-diabetic EH patients, including 54 with IR and 27 without IR, were enrolled. After two weeks wash-out, patients with IR were randomly assigned to telmisartan (group T) or amlodipine (group A) for 6 months. Blood samples were taken before and after treatment for measurement of routine biochemical parameters, visfatin and insulin resistance (measured by HOMA-IR). Visfatin was independently correlated with HOMA-IR (r=0.845, P=0.000). After 6 months of treatment, both drugs lowered HOMA-IR, more significantly so in group T than group A (P=0.010). Serum visfatin levels increased in group T but decreased in group A. Serum visfatin levels were higher in non-diabetic EH patients with IR compared with those without IR. Visfatin is independently correlated with HOMA-IR. Telmisartan lowers HOMA-IR to a greater extent than amlodipine. Interestingly, serum visfatin increased with telmisartan yet decreased with amlodipine treatment. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-02-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-02-01

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

  11. Demonstrated brain insulin resistance in Alzheimer’s disease patients is associated with IGF-1 resistance, IRS-1 dysregulation, and cognitive decline

    Science.gov (United States)

    Talbot, Konrad; Wang, Hoau-Yan; Kazi, Hala; Han, Li-Ying; Bakshi, Kalindi P.; Stucky, Andres; Fuino, Robert L.; Kawaguchi, Krista R.; Samoyedny, Andrew J.; Wilson, Robert S.; Arvanitakis, Zoe; Schneider, Julie A.; Wolf, Bryan A.; Bennett, David A.; Trojanowski, John Q.; Arnold, Steven E.

    2012-01-01

    While a potential causal factor in Alzheimer’s disease (AD), brain insulin resistance has not been demonstrated directly in that disorder. We provide such a demonstration here by showing that the hippocampal formation (HF) and, to a lesser degree, the cerebellar cortex in AD cases without diabetes exhibit markedly reduced responses to insulin signaling in the IR→IRS-1→PI3K signaling pathway with greatly reduced responses to IGF-1 in the IGF-1R→IRS-2→PI3K signaling pathway. Reduced insulin responses were maximal at the level of IRS-1 and were consistently associated with basal elevations in IRS-1 phosphorylated at serine 616 (IRS-1 pS616) and IRS-1 pS636/639. In the HF, these candidate biomarkers of brain insulin resistance increased commonly and progressively from normal cases to mild cognitively impaired cases to AD cases regardless of diabetes or APOE ε4 status. Levels of IRS-1 pS616 and IRS-1 pS636/639 and their activated kinases correlated positively with those of oligomeric Aβ plaques and were negatively associated with episodic and working memory, even after adjusting for Aβ plaques, neurofibrillary tangles, and APOE ε4. Brain insulin resistance thus appears to be an early and common feature of AD, a phenomenon accompanied by IGF-1 resistance and closely associated with IRS-1 dysfunction potentially triggered by Aβ oligomers and yet promoting cognitive decline independent of classic AD pathology. PMID:22476197

  12. Study on the phenomenon of insulin resistance (IR) in patients with acute cerebral infarction

    International Nuclear Information System (INIS)

    Chen Xinhua; Wang Genfa; Yu Lihua

    2007-01-01

    Objective: To investigate the presence of insulin resistance (IR) in patients with cerebral infarction and the indication for insulin therapy. Methods: Fasting blood glucose (FPG) (with biochemistry), fasting serum insulin (FINS) and cortisol (with RIA) levels were measured in 50 patients with cerebral infarction and 80 controls. Insulin sensitivity index (ISI) was calculated and correlation with the score of neurologic impairment as well as the size of lesion was studied. Results: FPG, FINS and cortisol levels in the patients were significantly higher than those in the controls (P<0.001 ) while the ISI was significantly lower (P <0.001 ) than that in the controls. Levels of there parameters were significantly higher in patients with moderate-severe lesions than those in patients with only mild lesion (P<0.001, P<0.01, P<0.05 respectively). ISI was negatively correlated to the size of infarction (r=-0.313, P<0.05) and also to the score of neurologic impairment (r=-0.317, P<0.05). The mortality and morbidity in the moderate severe group were naturally higher than those in the mild group. Conclusion: Insulin resistance does exist during the acute stage of cerebral infarction. Degree of hyperinsulinaemia and severity of the resistance are related to the course and prognosis of the disease process. Insulin therapy should be considered in those patients with hyperglycemia. (authors)

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

    International Nuclear Information System (INIS)

    1974-01-01

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

  14. Radiation-resistance assessment of IR fibres for ITER thermography diagnostic system

    International Nuclear Information System (INIS)

    Brichard, B.; Ierschot, S. van; Ooms, H.; Berghmans, F.; Reichle, R.; Pocheau, C.; Decreton, M.

    2006-01-01

    The actively cooled target plates in the divertor of ITER will be subjected to high thermal fluxes (∼ 10 MW/m 2 ). These target plates are compound structures of an armour material at the surface - either carbon fibre reinforced carbon (CFC) or tungsten - and a water cooled CuCrZr structure inside or below. The thermal limit of the interface between the two materials must not exceed 550 o C. Therefore, the temperature must be carefully monitored to prevent structural damages of the divertor plates. Non contact measurements of the temperature offer the advantage to avoid weakening of the cooling plate structure which is already quite complex to manufacture. Infrared thermography of the target surface is therefore considered as a possible solution. Recently a diagnostic concept for spectrally resolved ITER divertor thermography using optical fibres has been proposed by CEA-Cadarache. However, the divertor region will have to face high-radiation flux and the radiation-resistance of InfraRed (IR)-fibres must be evaluated. In collaboration with CEA-Cadarache, an irradiation program has been started at SCK-CEN (Mol, Belgium) with the aim to measure the radiation-induced absorption of different IR fibre candidates operating in the 1-5 μm range. We selected various commercially available IR technologies: ZrF 4 , Hollow-Waveguide, Sapphire and Chalcogenide. For wavelengths below 2 μm we also tested low-OH silica fibres. We carried out a gamma irradiation at a maximum dose-rate of 0.42 Gy/s up to a total dose of about 5000 Gy. We showed that the optical transmission of ZrF 4 fibres strongly decreased under gamma radiation, primarily for wavelengths below 2 μm. In this type of fibre typical optical losses can reach 50 % at 5000 Gy around 3 μm. Nevertheless, the optical transmission can be significantly recovered by performing a thermal annealing treatment at a temperature of 100 o C. We also irradiated a Silver-coated hollow waveguide fibre at the same dose-rate but up

  15. Impacto do volume de gordura aspirado na resistência insulínica após lipoaspiração Impact of the aspirated volume of fat tissue in the insulin resistance after liposuction

    Directory of Open Access Journals (Sweden)

    Sérgio de Souza Oliveira

    2013-02-01

    Full Text Available OBJETIVO: investigar a resistência insulínica imposta pela lipoaspiração, correlacionando sua intensidade com a extensão da operação. MÉTODOS: A amostra foi formada de 20 pacientes do sexo feminino sem comorbidades, com idade entre 21 e 43 anos, índice de massa corporal entre 19 e 27 Kg/m², submetidas à lipoaspiração isolada ou associada à prótese de mamas. Foram coletados os indicadores de resistência insulínica no início e término da cirurgia para o cálculo do Homeostasis Model Assessment (HOMA-IR. As variáveis operatórias foram tempo de lipoaspiração, tempo de prótese de mamas, áreas corporais lipoaspiradas e gordura total aspirada. RESULTADOS: O tempo de lipoaspiração foi 94 a 278 min (média=174 min, tempo de prótese de mamas de 20 a 140 min (média=65 min, gordura total aspirada de 680 a 4280 g (média=1778 g. A análise estatística foi realizada por uma linha de corte de 1500 g de gordura aspirada e revelou uma resistência insulínica pelo índice de HOMA significativamente mais intensa no grupo >1500 g (aumento de 123% em relação ao grupo d"1500 g (aumento de 53%, a partir dos dados basais (p=0,02. As demais variáveis operatórias não apresentaram correlação significativa. CONCLUSÃO: A resistência insulínica apresenta aumento significativo na lipoaspiração, correlacionada ao volume de gordura aspirado.OBJECTIVE: To investigate insulin resistance imposed by liposuction, correlating its intensity with the extent of the operation. METHODS: The sample consisted of 20 female patients without comorbidities, aged between 21 and 43 years, body mass index between 19 and 27 kg/m², undergoing liposuction alone or associated with breasts' prosthesis. We assessed insulin resistance at the beginning and end of the procedure by calculating the Homeostasis Model Assessment (HOMA-IR. The operative variables were length of liposuction, breast prosthesis time, body areas submitted to liposuction and total fat

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

    International Nuclear Information System (INIS)

    Chou, H.-M.

    2003-01-01

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

  17. New Ablation-Resistant Material Candidate for Hypersonic Applications: Synthesis, Composition, and Oxidation Resistance of HfIr3-Based Solid Solution.

    Science.gov (United States)

    Lozanov, Victor V; Baklanova, Natalya I; Bulina, Natalia V; Titov, Anatoly T

    2018-04-18

    The peculiarities of the solid-state interaction in the HfC-Ir system have been studied within the 1000-1600 °C temperature range using a set of modern analytical techniques. It was stated that the interaction of HfC with iridium becomes noticeable at temperatures as low as 1000-1100 °C and results in the formation of HfIr 3 -based substitutional solid solution. The homogeneity range of the HfIr 3± x phase was evaluated and refined as HfIr 2.43 -HfIr 3.36 . The durability of the HfIr 3 -based system under extreme environmental conditions was studied. It was shown that the HfIr 3 -based material displays excellent ablation resistance under extreme environmental conditions. The benefits of the new designed material result from its relative oxygen impermeability and special microstructure similar to superalloys. The results obtained in this work allow us to consider HfIr 3 as a very promising candidate for extreme applications.

  18. Higher HOMA-IR index and correlated factors of insulin resistance in patients with IgA nephropathy.

    Science.gov (United States)

    Yang, Yue; Wei, Ri-Bao; Wang, Yuan-da; Zhang, Xue-Guang; Rong, Na; Tang, Li; Chen, Xiang-Mei

    2012-11-01

    To investigate the index of homeostasis model of insulin resistance (HOMA-IR) in IgA nephropathy (IgAN) patients, and to explore the possible correlated factors contributing to insulin resistance (IR) within these patients. There were 255 IgAN patients and 45 membranous nephropathy (MN) patients in our database. We identified 89 IgAN subjects and 21 MN subjects without diabetes and undergoing glucocorticoid therapy for at least 6 months. Data regarding physical examination, blood chemistry and renal pathology were collected from 89 IgAN subjects and 21 MN subjects. Then 62 IgAN patients and 19 MN patients with chronic kidney disease (CKD) Stage 1 - 2 were selected for the comparison of HOMA-IR index, 89 IgAN patients were selected for multiple regression analysis to test for correlated factors of HOMA-IR index with IgAN patients. Comparison between IgAN and MN show that HOMA-IR index was significantly higher in IgAN patients with CKD Stage 1 - 2. After logarithmic transformation with urine protein (UPr), Ln(UPr) (b = 0.186, p = 0.008), eGFR (b = -0.005, p = 0.014), > 50% of glomeruli with mesangial hypercellularity (b = 0.285, p = 0.027) and body mass index (BMI) (b = 0.039, p = 0.008) were correlated factors of HOMA-IR index in the multiple regression analysis. IgAN patients had higher HOMA-IR index compared with MN in the stages of CKD 1 - 2. For IgAN patients, more UPr, lower eGFR, > 50% of glomeruli with mesangial hypercellularity and higher BMI were correlated with IR.

  19. Pressure-Induced Confined Metal from the Mott Insulator Sr3Ir2O7

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Yang; Yang, Liuxiang; Chen, Cheng-Chien; Kim, Heung-Sik; Han, Myung Joon; Luo, Wei; Feng, Zhenxing; Upton, Mary; Casa, Diego; Kim, Jungho; Gog, Thomas; Zeng, Zhidan; Cao, Gang; Mao, Ho-kwang; van Veenendaal, Michel

    2016-05-24

    The spin-orbit Mott insulator Sr3Ir2O7 provides a fascinating playground to explore insulator-metal transition driven by intertwined charge, spin, and lattice degrees of freedom. Here, we report high-pressure electric resistance and resonant inelastic x-ray scattering measurements on single-crystal Sr3Ir2O7 up to 63-65 GPa at 300 K. The material becomes a confined metal at 59.5 GPa, showing metallicity in the ab plane but an insulating behavior along the c axis. Such an unusual phenomenon resembles the strange metal phase in cuprate superconductors. Since there is no sign of the collapse of spin-orbit or Coulomb interactions in x-ray measurements, this novel insulator-metal transition is potentially driven by a first-order structural change at nearby pressures. Our discovery points to a new approach for synthesizing functional materials.

  20. Effects of Dioscorea esculenta and Eubacterium rectale on insulin receptor substrate 1 (Irs1 Expression in skeletal muscle and homeostatic model assessment-insulin resistance (HOMA-IR in diabetic rats

    Directory of Open Access Journals (Sweden)

    . Sunarti

    2017-01-01

    Full Text Available Low expression of insulin receptor substrate 1 (Irs1 is associated with insulin resistance and type 2 diabetes mellitus (type 2 DM. This study was performed to evaluate the effects of Dioscorea esculenta and Eubacterium rectale on the Irs1 expression in the skeletal muscle and the homeostatic model assessment-insulin resistance (HOMA-IR of diabetic rats. Twenty-five male Wistar rats were divided into five groups i.e. non diabetic rats Group 1; diabetic rats as Group 2; diabetic rats + D. esculenta as Group 3; diabetic rats + E.rectale as Group 4 and diabetic rats + both E. rectale and D. esculenta as Group 5. Rats were made diabetic with induction of intraperitoneally injection of nicotinamide and streptozotocin. After four weeks of the interventions, the blood and skeletal muscles were taken. The Irs1 expression was analyzed with immunohistochemical staining, plasma glucose levels was analyzed using a spectrophotometer, and insulin was analyzed using ELISA methods. All intervention groups reduced plasma glucose levels and HOMA-IRs (p<0.001 and increased Irs1 expression. The greatest reduction of  plasma glucose levels and increase of Irs1 expression in the skeletal muscle were found in Group 4, however, the lowest of HOMA-IR was seen in Group 5. These results suggested that D.esculenta, E.rectale, and the combination reduced plasma glucose levels and HOMA-IR by increasing Irs1 expression in skeletal muscle.

  1. Overcoming IGF1R/IR Resistance Through Inhibition of MEK Signaling in Colorectal Cancer Models

    Science.gov (United States)

    Flanigan, Sara A.; Pitts, Todd M.; Newton, Timothy P.; Kulikowski, Gillian N.; Tan, Aik Choon; McManus, Martine C.; Spreafico, Anna; Kachaeva, Maria I.; Selby, Heather M.; Tentler, John J.; Eckhardt, S. Gail; Leong, Stephen

    2013-01-01

    Purpose Results from clinical trials involving resistance to molecularly targeted therapies have revealed the importance of rational single agent and combination treatment strategies. In this study, we tested the efficacy of a type 1 insulin-like growth factor receptor (IGF1R)/insulin receptor (IR) tyrosine kinase inhibitor (TKI), OSI-906, in combination with a MEK 1/2 inhibitor based on evidence that the MAPK pathway was upregulated in colorectal cancer (CRC) cell lines that were resistant to OSI-906. Experimental Design The antiproliferative effects of OSI-906 and the MEK 1/2 inhibitor U0126, were analyzed both as single agents and in combination in 13 CRC cell lines in vitro. Apoptosis, downstream effector proteins, and cell cycle were also assessed. Additionally, the efficacy of OSI-906 combined with the MEK 1/2 inhibitor selumetinib (AZD6244, ARRY-142886), was evaluated in vivo using human CRC xenograft models. Results The combination of OSI-906 and U0126 resulted in synergistic effects in 11 out of 13 CRC cell lines tested. This synergy was variably associated with apoptosis or cell cycle arrest in addition to molecular effects on pro-survival pathways. The synergy was also reflected in the in vivo xenograft studies following treatment with the combination of OSI-906 and selumetinib. Conclusions Results from this study demonstrate synergistic antiproliferative effects in response to the combination of OSI-906 with a MEK 1/2 inhibitor in CRC cell line models both in vitro and in vivo, which supports the rational combination of OSI-906 with a MEK inhibitor in patients with CRC. PMID:24045180

  2. Evaluation of insulin resistance improvement after laparoscopic sleeve gastrectomy or gastric bypass surgery with HOMA-IR.

    Science.gov (United States)

    Zhu, Yubing; Sun, Zhipeng; Du, Yanmin; Xu, Guangzhong; Gong, Ke; Zhu, Bin; Zhang, Nengwei

    2017-01-01

    Our purpose was to explore the remission of insulin resistance after bariatric surgery to discover the mechanism of diabetes remission excluding dietary factors. A retrospective case control study was conducted on patients with type 2 diabetes, who underwent laparoscopic sleeve gastrectomy (LSG) or laparoscopic gastric bypass surgery (LGB) in Beijing Shijitan Hospital from April 1, 2012 to April 1, 2013. The laboratory and anthropometric data was analyzed pre-surgery and during a 2-year follow-up. HOMA-IR was calculated and evaluated. The two surgical procedures were compared. No significant difference in complete remission rate was observed between the two groups (LGB group: 62.1%, LSG group: 60.0%, p = 0.892). HOMA-IR was reduced to a stable level at the 3 rd month after surgery. The cut-off value of HOMA-IR was 2.38 (sensitivity: 0.938, specificity: 0.75) and 2.33 (sensitivity: 0.941, specificity: 0.778) respectively for complete remission after LSG or LGB surgery. Insulin resistance was improved while GLP-1 and Ghrelin was changed significantly in patients with type 2 diabetes prior to weight loss either in the LSG or LGB group. HOMA-IR decreased to less than the cut-off value at the 3 rd month and was closely related to complete remission. The mechanism of bariatric surgery was not due just to simply dietary factors or body weight loss but also the remission of insulin resistance.

  3. Non-destructive reversible resistive switching in Cr doped Mott insulator Ca2RuO4: Interface vs bulk effects

    KAUST Repository

    Shen, Shida; Williamson, Morgan; Cao, Gang; Zhou, Jianshi; Goodenough, John; Tsoi, Maxim

    2017-01-01

    A non-destructive reversible resistive switching is demonstrated in single crystals of Cr-doped Mott insulator Ca2RuO4. An applied electrical bias was shown to reduce the DC resistance of the crystal by as much as 75%. The original resistance

  4. Condition Assessment of Paper Insulation in Oil-Immersed Power Transformers Based on the Iterative Inversion of Resistivity

    Directory of Open Access Journals (Sweden)

    Jiangjun Ruan

    2017-04-01

    Full Text Available The resistivity of oil impregnated paper will decrease during its aging process. This paper takes paper resistivity as an assessment index to evaluate the insulation condition of oil impregnated paper in power transformer. The feasibility of this method are discussed in two aspects: reliability and sensitivity. Iterative inversion of paper resistivity was combined with finite element simulation. Both the bisection method and Newton’s method were used as iterative methods. After the analysis and comparison, Newton’s method was selected as the first option of paper resistivity iteration for its faster convergence. In order to consider the spatial distribution characteristic of paper aging and enhance the calculation accuracy, the resistivity calculation is expanded to a multivariate iteration based on Newton’s method, in order to consider the spatial distribution characteristic of paper aging and improve the calculation accuracy. This paper presents an exploratory research on condition assessment of oil impregnated paper insulation, and provides some reference to the security and economy operation of power transformers.

  5. Induction of resistance to blast disease in an elite rice cultivar 'IR 50'

    International Nuclear Information System (INIS)

    Sarma, N.P.; Rao, G.J.N.; Row, K.V.S.R.K.

    2001-01-01

    Full text: One of the most promising techniques for producing disease resistant forms of plants is the use of mutagenic agents. It has been demonstrated by several workers that genetic variability for several desired characters can be induced successfully through mutations and its practical value in plant improvement programmes has been well established. The main advantage of mutation breeding is the possibility of improving one or two characters without changing the rest of the genotype. The elite cultivar, 'IR 50' (IR 2153-14-1-6-2/IR 28//IR 36) was developed at IRRI, Los Banos, The Philippines and was released in India for the State of Tamil Nadu in 1982. It is highly responsive to fertilizer, records high yields and possesses good grain characters. It matured in just more than 100 days and was ideal for both samba and navarai seasons in Tamil Nadu. But, the cultivar was shown to be highly susceptible to blast (causative organism Magnaportha grisea) causing extensive losses year after year. With the objective of developing high yielding, blast tolerant mutant lines from IR 50, the mutation approach was adopted and both physical (gamma-rays from 60 Co) and chemical mutagens (EMS - ethyl methanesulphonate and sodium azide) were employed on dry seeds. The M1 generation was grown in closely spaced plants. One hundred and sixty-eight derived families were grown in M 2 . In M 3 generation, 128 M 3 families were further selected for evaluation in M4 and M5. Based on evaluation of yield and other attributes, a total of 85 mutants were finally selected and evaluated for their stability. In selection of the mutants, it was ensured that all the selected mutants resemble the parent for both agronomic and quality characteristics. The evaluation of these mutant lines for the level of tolerance to blast disease was conducted at CRRI over a number of years under both artificial and natural conditions. These mutant lines showed varied levels of tolerance to blast in comparison

  6. Bipolar resistive switching in graphene oxide based metal insulator metal structure for non-volatile memory applications

    Science.gov (United States)

    Singh, Rakesh; Kumar, Ravi; Kumar, Anil; Kashyap, Rajesh; Kumar, Mukesh; Kumar, Dinesh

    2018-05-01

    Graphene oxide based devices have attracted much attention recently because of their possible application in next generation electronic devices. In this study, bipolar resistive switching characteristics of graphene oxide based metal insulator metal structure were investigated for nonvolatile memories. The graphene oxide was prepared by the conventional Hummer's method and deposited on ITO coated glass by spin-coating technique. The dominant mechanism of resistive switching is the formation and rupture of the conductive filament inside the graphene oxide. The conduction mechanism for low and high resistance states are dominated by two mechanism the ohmic conduction and space charge limited current (SCLC) mechanism, respectively. Atomic Force Microscopy, X-ray diffraction, Cyclic-Voltammetry were conducted to observe the morphology, structure and behavior of the material. The fabricated device with Al/GO/ITO structure exhibited reliable bipolar resistive switching with set & reset voltage of -2.3 V and 3V respectively.

  7. Linking lifestyle factors and insulin resistance, based on fasting plasma insulin and HOMA-IR in middle-aged Japanese men: a cross-sectional study.

    Science.gov (United States)

    Otake, Toshie; Fukumoto, Jin; Abe, Masao; Takemura, Shigeki; Mihn, Pham Ngoc; Mizoue, Tetsuya; Kiyohara, Chikako

    2014-09-01

    Insulin resistance (IR) is regarded as one of the earliest features of many metabolic diseases, and major efforts are aimed at improving insulin function to confront this issue. The aim of this study was to investigate the relationship of body mass index (BMI), cigarette smoking, alcohol intake, physical activity, green tea and coffee consumption to IR. We performed a cross-sectional study of 1542 male self defense officials. IR was defined as the highest quartile of the fasting plasma insulin (≥ 50 pmol/L) or the homeostasis model assessment-estimated IR (HOMA-IR ≥ 1.81). An unconditional logistic model was used to estimate the odds ratio (OR) and 95% confidence interval (CI) for the association between IR and influential factors. Stratified analysis by obesity status (BMI IR was significantly positively related to BMI and glucose tolerance, negatively related to alcohol use. Independent of obesity status, significant trends were observed between IR and alcohol use. Drinking 30 mL or more of ethanol per day reduced IR by less than 40%. Strong physical activity was associated with decreased risk of IR based on fasting plasma insulin only in the obese. Coffee consumption was inversely associated with the risk of IR based on HOMA-IR in the non-obese group. Higher coffee consumption may be protective against IR among only the non-obese. Further studies are warranted to examine the effect modification of the obesity status on the coffee-IR association.

  8. Analysis of IRS-1-mediated phosphatidylinositol 3-kinase activation in the adipose tissue of polycystic ovary syndrome patients complicated with insulin resistance

    Energy Technology Data Exchange (ETDEWEB)

    Yongli, Chu [Yantai Yuhuangding Hospital, Yantai (China). Dept. of Obstetrics and Gynecology; Hongyu, Qiu; Yongyu, Sun; Min, Li; Hongfa, Li

    2004-04-01

    Objective: To investigate the insulin receptor substance-1 (IRS-1)-mediated phosphatidylinositol-3 (PI-3) kinase activity in adipose tissue of polycystic ovary syndrome (PCOS) patients, and to explore molecular mechanisms of insulin resistance of PCOS. Methods: Blood and adipose tissue samples from patients with PCOS with insulin resistance (n=19), PCOS without insulin resistance (n=10) and controls (n=15) were collected. Serum luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone (T) were measured by chemiluminescence assay. Fasting insulin (FIN) was measured by radioimmunoassay. Fasting plasma glucose (FPG) was measured by oxidase assay. Insulin resistance index (IR) was calculated using homeostasis model assessment (HOMA) to analyze the relationship between these markers and insulin resistance. The tyrosine phosphorylation of IRS-1 was measured by immunoprecipitation and enhanced chemiluminescent immunoblotting technique. PI-3 kinase activity was detected by immunoprecipitation, thin-layer chromatography and gamma scintillation counting. The results were analyzed by statistical methods. Results: 1) The levels of serum LH, LH/FSH, T, FIN and HOMA-IR in PCOS without insulin resistance were significantly higher than those of control group (all P<0.05); the levels of serum LH, LH/FSH, T, FIN and HOMA-IR in PCOS with insulin resistance were significantly higher than those of PCOS without insulin resistance (all P<0.05). 2) The tyrosine phosphorylation analysis of IRS-1 showed that IRS-1 tyrosine phosphorylation was significantly decreased in PCOS with insulin resistance compared to that of PCOS without insulin resistance and control groups (P<0.01). 3) PI-3 kinase activity was significantly decreased (P<0.01) and negatively correlated with HOMA-IR. Conclusion: In consequence of the weaker signal caused by the change of upper stream signal molecule IRS-1 tyrosine phosphorylation, PI-3 kinase activity decreased, it affects the insulin signal

  9. Analysis of IRS-1-mediated phosphatidylinositol 3-kinase activation in the adipose tissue of polycystic ovary syndrome patients complicated with insulin resistance

    International Nuclear Information System (INIS)

    Chu Yongli; Qiu Hongyu; Sun Yongyu; Li Min; Li Hongfa

    2004-01-01

    Objective: To investigate the insulin receptor substance-1 (IRS-1)-mediated phosphatidylinositol-3 (PI-3) kinase activity in adipose tissue of polycystic ovary syndrome (PCOS) patients, and to explore molecular mechanisms of insulin resistance of PCOS. Methods: Blood and adipose tissue samples from patients with PCOS with insulin resistance (n=19), PCOS without insulin resistance (n=10) and controls (n=15) were collected. Serum luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone (T) were measured by chemiluminescence assay. Fasting insulin (FIN) was measured by radioimmunoassay. Fasting plasma glucose (FPG) was measured by oxidase assay. Insulin resistance index (IR) was calculated using homeostasis model assessment (HOMA) to analyze the relationship between these markers and insulin resistance. The tyrosine phosphorylation of IRS-1 was measured by immunoprecipitation and enhanced chemiluminescent immunoblotting technique. PI-3 kinase activity was detected by immunoprecipitation, thin-layer chromatography and gamma scintillation counting. The results were analyzed by statistical methods. Results: 1) The levels of serum LH, LH/FSH, T, FIN and HOMA-IR in PCOS without insulin resistance were significantly higher than those of control group (all P<0.05); the levels of serum LH, LH/FSH, T, FIN and HOMA-IR in PCOS with insulin resistance were significantly higher than those of PCOS without insulin resistance (all P<0.05). 2) The tyrosine phosphorylation analysis of IRS-1 showed that IRS-1 tyrosine phosphorylation was significantly decreased in PCOS with insulin resistance compared to that of PCOS without insulin resistance and control groups (P<0.01). 3) PI-3 kinase activity was significantly decreased (P<0.01) and negatively correlated with HOMA-IR. Conclusion: In consequence of the weaker signal caused by the change of upper stream signal molecule IRS-1 tyrosine phosphorylation, PI-3 kinase activity decreased, it affects the insulin signal

  10. Insulin resistance in obese children and adolescents: HOMA-IR cut-off levels in the prepubertal and pubertal periods.

    Science.gov (United States)

    Kurtoğlu, Selim; Hatipoğlu, Nihal; Mazıcıoğlu, Mümtaz; Kendirici, Mustafa; Keskin, Mehmet; Kondolot, Meda

    2010-01-01

    Childhood obesity is associated with an increased risk for insulin resistance. The underlying mechanism for the physiological increase in insulin levels in puberty is not clearly understood. The aim of the present study was to determine the cut-off values for homeostasis model assessment for insulin resistance (HOMA-IR) in obese children and adolescents according to gender and pubertal status. Two hundred and eight obese children and adolescents (141 girls, 127 boys) aged between 5 and 18 years were included in the study. The children were divided into prepubertal and pubertal groups. A standard oral glucose tolerance test (OGTT) was carried out in all children. A total insulin level exceeding 300 μU/mL in the blood samples, collected during the test period, was taken as the insulin resistance criterion. Cut-off values for HOMA-IR were calculated by receiver operating characteristic (ROC) analysis. In the prepubertal period, the rate of insulin resistance was found to be 37% in boys and 27.8% in girls,while in the pubertal period, this rate was 61.7% in boys and 66.7% in girls. HOMA-IR cut-off values for insulin resistance in the prepubertal period were calculated to be 2.67 (sensitivity 88.2%, specificity 65.5%) in boys and 2.22 (sensitivity 100%, specificity 42.3%) in girls, and in the pubertal period, they were 5.22 (sensitivity 56%, specificity 93.3%) in boys and 3.82 (sensitivity 77.1%, specificity 71.4%) in girls. Since gender, obesity and pubertal status are factors affecting insulin resistance, cut-off values which depend on gender and pubertal status, should be used in evaluation of insulin resistance.

  11. A Role for IR-β in the Free Fatty Acid Mediated Development of Hepatic Insulin Resistance?

    Directory of Open Access Journals (Sweden)

    Arthur G. Cox

    2009-10-01

    Full Text Available Several studies have been conducted to elucidate the role of free fatty acids (FFAs in the pathogenesis of type 2 diabetes, but the exact molecular mechanism by which FFAs alter glucose metabolism in the liver is still not completely understood.1-4 In a recent publication, Ragheb and co-workers have examined the effect of free fatty acid (FFA treatment on insulin signaling and insulin resistance by using immunoprecipitation and immunoblotting to study the effect of high concentrations of insulin and FFAs on insulin receptor-beta (IR-β and downstream elements in the PI3K pathway using the fructose-fed hamster model.5 Their results clearly show that free fatty acids have an insignificant effect on IR-β and supports previous findings that FFAs lead to insulin resistance in the liver via the PKC-NFĸB pathway.2,3

  12. Analysis of Printing Substrate, Ink Age and Number of IR Drying Influence on Electrical Resistance of Conductive Inks

    Directory of Open Access Journals (Sweden)

    Josip Jerić

    2015-05-01

    Full Text Available As a result of availability of new technologies, functional printing as a segment has become one of the most interesting directions of research and development in graphic technology. Conductive inks are not a novelty and they already have broad possibilities in production of everyday products. There is still a big market for the broadening of their use, as well as a possibility of further enhancing their properties. This paper analyzes the influence of printing substrate, age of ink and the number of IR drying on the electrical resistance of the conductive inks. In the paper, subject of analysis was the change of electrical resistance in the line that was 9 cm long and 10 typographic points wide. The semi-automated screen-printing machine was used for printing. Three types of printing substrates were used; uncoated, coated and recycled paper. Two types of inks were used; newly opened ink and ink that was out of date for half year. After the printing, prints were dried using the IR dryer. Prints were dried once, and then additional three times. After the first and last drying, multimeter was used to measure electrical resistance of the lines. Analysis of the data shows that the older ink produces prints with higher electrical resistance. There are also notable differences in the electrical resistance based on the printing substrate.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  14. Temperature dependence of hole mobility in Mott insulators: Normal-state resistivity of high-T/sub c/ superconductors

    International Nuclear Information System (INIS)

    Kumar, N.

    1989-01-01

    We consider the diffusion of a hole injected in a Mott insulator described by a one-band Hubbard Hamiltonian at half-filling and in the atomic limit. The diffusion coefficient turns out to be temperature independent exactly giving 1/T dependence for the drift mobility via the Einstein relation. This is in marked disagreement with the (1/T)/sup 1/2/ dependence obtaining in the self-retracing path approximation at low temperatures. We note the possible relevance of our result to the linear T dependence of the normal-state resistivity observed in the high-T/sub c/ oxide superconductors

  15. The HOMA-Adiponectin (HOMA-AD) Closely Mirrors the HOMA-IR Index in the Screening of Insulin Resistance in the Brazilian Metabolic Syndrome Study (BRAMS).

    Science.gov (United States)

    Vilela, Brunna Sullara; Vasques, Ana Carolina Junqueira; Cassani, Roberta Soares Lara; Forti, Adriana Costa E; Pareja, José Carlos; Tambascia, Marcos Antonio; Geloneze, Bruno

    2016-01-01

    The major adverse consequences of obesity are associated with the development of insulin resistance (IR) and adiposopathy. The Homeostasis Model Assessment-Adiponectin (HOMA-AD) was proposed as a modified version of the HOMA1-IR, which incorporates adiponectin in the denominator of the index. To evaluate the performance of the HOMA-AD index compared with the HOMA1-IR index as a surrogate marker of IR in women, and to establish the cutoff value of the HOMA-AD. The Brazilian Metabolic Syndrome Study (BRAMS) is a cross-sectional multicenter survey. The data from 1,061 subjects met the desired criteria: 18-65 years old, BMI: 18.5-49.9 Kg/m² and without diabetes. The IR was assessed by the indexes HOMA1-IR and HOMA-AD (total sample) and by the hyperglycemic clamp (n = 49). Metabolic syndrome was defined using the IDF criteria. For the IR assessed by the clamp, the HOMA-AD demonstrated a stronger coefficient of correlation (r = -0.64) compared with the HOMA1-IR (r = -0.56); p HOMA1-IR, the HOMA-AD showed higher values of the AUC for the identification of IR based on the clamp test (AUC: 0.844 vs. AUC: 0.804) and on the metabolic syndrome (AUC: 0.703 vs. AUC: 0.689), respectively; p HOMA-AD in comparison with the HOMA1-IR in the diagnosis of IR and metabolic syndrome (p > 0.05). The optimal cutoff identified for the HOMA-AD for the diagnosis of IR was 0.95. The HOMA-AD index was demonstrated to be a useful surrogate marker for detecting IR among adult women and presented a similar performance compared with the HOMA1-IR index. These results may assist physicians and researchers in determining which method to use to evaluate IR in light of the available facilities.

  16. Estimating Rate of Insulin Resistance in Patients with Preeclampsia Using HOMA-IR Index and Comparison with Nonpreeclampsia Pregnant Women

    Directory of Open Access Journals (Sweden)

    Farideh Rezaei Abhari

    2014-01-01

    Full Text Available Women with preeclampsia, independent of obesity and glucose intolerance, exhibit insulin resistance during pregnancy. The purpose of the present study is to determine whether early diagnosis of insulin resistance during pregnancy can predict preeclampsia. Through a case-control study, 675 pregnant women were selected and their first trimester blood was taken. Their fasting blood glucose and insulin were also measured after diagnosis of preeclampsia by 20 weeks of pregnancy. Based on the experiments conducted on 675 women who were 20 weeks past their pregnancy, 375 cases with preeclampsia were selected and assigned to the case group. 35 other pregnant women were put in the control group. Diagnosis criteria for the participants included blood pressure above 140/90 and proteinuria above 300 mg or above +1. Both groups were matched according to age, parity, gestational age, and BMI. Homa-Irand rate of insulin resistance was calculated by HOMA-IR and patients were followed up. Homeostatic model assessments (HOMA-IR revealed that the average insulin resistance increased during pregnancy among both the case and control groups. There was a significant difference between insulin resistance of these two groups in both first trimester and third trimester and after developing preeclampsia (P < 0.001, P = 0.021. Insulin-resistance of the group with preeclampsia was higher in first trimester prior to diagnosis as well as the third trimester after diagnosis compared to natural pregnancy under similar conditions. Measurement of insulin resistance in first trimester may be useful in predicting the risk of preeclampsia.

  17. Estimating rate of insulin resistance in patients with preeclampsia using HOMA-IR index and comparison with nonpreeclampsia pregnant women.

    Science.gov (United States)

    Abhari, Farideh Rezaei; Ghanbari Andarieh, Maryam; Farokhfar, Asadollah; Ahmady, Soleiman

    2014-01-01

    Women with preeclampsia, independent of obesity and glucose intolerance, exhibit insulin resistance during pregnancy. The purpose of the present study is to determine whether early diagnosis of insulin resistance during pregnancy can predict preeclampsia. Through a case-control study, 675 pregnant women were selected and their first trimester blood was taken. Their fasting blood glucose and insulin were also measured after diagnosis of preeclampsia by 20 weeks of pregnancy. Based on the experiments conducted on 675 women who were 20 weeks past their pregnancy, 375 cases with preeclampsia were selected and assigned to the case group. 35 other pregnant women were put in the control group. Diagnosis criteria for the participants included blood pressure above 140/90 and proteinuria above 300 mg or above +1. Both groups were matched according to age, parity, gestational age, and BMI. Homa-Irand rate of insulin resistance was calculated by HOMA-IR and patients were followed up. Homeostatic model assessments (HOMA-IR) revealed that the average insulin resistance increased during pregnancy among both the case and control groups. There was a significant difference between insulin resistance of these two groups in both first trimester and third trimester and after developing preeclampsia (P < 0.001, P = 0.021). Insulin-resistance of the group with preeclampsia was higher in first trimester prior to diagnosis as well as the third trimester after diagnosis compared to natural pregnancy under similar conditions. Measurement of insulin resistance in first trimester may be useful in predicting the risk of preeclampsia.

  18. Association between Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and Components of Metabolic Syndrome in Young Chinese Men.

    Science.gov (United States)

    Ying, X; Song, Zh; Zhao, Ch; Jiang, Y

    2011-01-01

    To investigate the prevalence of metabolic syndrome (MetS) in young Chinese population and assess the association between HOMA-IR and different components of MetS in young Chinese men. Overall 5576 young Chinese subjects (age range [19-44 yr], 3636 men) were enrolled in, who visited our Health Care Center for a related health checkup from March to December 2008. The international diabetes federation (IDF) definition for MetS was used. The SPSS statistical package, version 11.5 was used for the statistical analysis. The prevalence of MetS was 21.81% in young men and 5.62% in young women. According to suffering from different numbers of MetS components, the male subjects were divided into four groups. Numbers of MetS components were more and HOMA-IR values were significantly higher. In this male population, the quartile of HOMA-IR was higher, values of triglyceride (TG), fasting plasma glucose (FBG), systolic blood pressure(SBP), diastolic blood pressure(DBP) and waist circumference (WC) were all significantly higher, as well as high density lipoprotein cholesterol (HDL-C) value was significantly lower (P= 0.000). In Spearman's correlation analysis, HOMA-IR was positively correlated with TG, FBG, SBP, DBP and WC, and negatively correlated with HDL-C (r= 0.460, 0.464, 0.362, 0.346, 0.586, -0.357, respectively, all P value= 0.000). The prevalence of MetS in these young Chinese men was obviously high. Insulin resistance played an important role in occurrence and development of MetS. Waist circumference was the best correlation with HOMA-IR among all components of MetS.

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

    International Nuclear Information System (INIS)

    Morita, Minoru; Kon, Shuji; Nishikawa, Ichiro

    1978-01-01

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

  20. Relationship of visfatin level to pancreatic endocrine hormone level, HOMA-IR index, and HOMA β-cell index in overweight women who performed hydraulic resistance exercise.

    Science.gov (United States)

    Ha, Chang Ho; Swearingin, Brenda; Jeon, Yong Kyun

    2015-09-01

    [Purpose] This study aimed to examine the correlation of visfatin level to pancreatic endocrine hormone level, homeostasis model assessment of insulin resistance (HOMA-IR) index, and HOMA β-cell index in hydraulic resistance exercise. Furthermore, it investigated the relationship between visfatin level and other variables affected by exercise in overweight women. [Subjects and Methods] The exercise group trained for 12 weeks, 70 minutes/day, 5 days/week. Visfatin level, pancreatic endocrine hormone level, HOMA-IR index, and HOMA β-cell index were measured before and after the intervention. Based on the blood insulin and glucose concentrations, HOMA-IR index, the indicator of insulin resistance, and HOMA β-cell index, the indicator of insulin secretion level, were assessed. [Results] Interaction effects on visfatin level, insulin level, HOMA-IR index, and HOMA β-cell index were observed. Interaction effects on glucagon and glucose levels were not observed between the intervention groups. The correlations of visfatin level to insulin, glucagon, and glucose levels, and HOMA-IR and HOMA β-cell indexes were not significant for any of the subjects. [Conclusion] Therefore, the 12-week resistance exercise affected body composition, visfatin level, insulin level, HOMA-IR index, and HOMA β-cell index. Finally, visfatin was not related to insulin, glucagon, and glucose levels, and HOMA-IR and HOMA β-cell indexes.

  1. A study of insulin resistance by HOMA-IR and its cut-off value to identify metabolic syndrome in urban Indian adolescents.

    Science.gov (United States)

    Singh, Yashpal; Garg, M K; Tandon, Nikhil; Marwaha, Raman Kumar

    2013-01-01

    Insulin resistance (IR) and associated metabolic abnormalities are increasingly being reported in the adolescent population. Cut-off value of homeostasis model of assessment IR (HOMA-IR) as an indicator of metabolic syndrome (MS) in adolescents has not been established. This study aimed to investigate IR by HOMA-IR in urban Indian adolescents and to establish cut-off values of HOMA-IR for defining MS. A total of 691 apparently healthy adolescents (295 with normal body mass index (BMI), 205 overweight, and 199 obese) were included in this cross-sectional study. MS in adolescents was defined by International Diabetes Federation (IDF) and Adult Treatment Panel III (ATP III) criteria. IR was calculated using the HOMA model. Mean height, waist circumference (WC), waist/hip ratio (WHR), waist/height ratio (WHtR), and blood pressure were significantly higher in boys as compared to girls. The HOMA-IR values increased progressively from normal weight to obese adolescents in both sexes. Mean HOMA-IR values increased progressively according to sexual maturity rating in both sexes. HOMA-IR value of 2.5 had a sensitivity of >70% and specificity of >60% for MS. This cut-off identified larger number of adolescents with MS in different BMI categories (19.7% in normal weight, 51.7% in overweight, and 77.0% in obese subjects) as compared to the use of IDF or ATP III criteria for diagnosing MS. Odds ratio for having IR (HOMA-IR of >2.5) was highest with WHtR (4.9, p pHOMA-IR increased with sexual maturity and with progression from normal to obese. A HOMA-IR cut-off of 2.5 provided the maximum sensitivity and specificity in diagnosing MS in both genders as per ATP III and IDF criteria.

  2. Field-tuned superconductor-insulator transitions and Hall resistance in thin polycrystalline MoN films

    Science.gov (United States)

    Makise, Kazumasa; Ichikawa, Fusao; Asano, Takayuki; Shinozaki, Bunju

    2018-02-01

    We report on the superconductor-insulator transitions (SITs) of disordered molybdenum nitride (MoN) thin films on (1 0 0) MgO substrates as a function of the film thickness and magnetic fields. The T c of the superconducting MoN films, which exhibit a sharp superconducting transition, monotonically decreases as the normal state R sq increases with a decreasing film thickness. For several films with different thicknesses, we estimate the critical field H c and the product zν  ≃  0.6 of the dynamical exponent z and the correlation length exponent ν using a finite scaling analysis. The value of this product can be explained by the (2  +  1) XY model. We found that the Hall resistance ΔR xy (H) is maximized when the magnetic field satisfies H HP(T) \\propto |1  -  T/T C0| in the superconducting state and also in the normal states owning to the superconducting fluctuation corresponding to the ghost critical magnetic field. We measured the Hall conductivity δσ xy (H)  =  σ xy (H)  -  σ xyn and fit the Gaussian approximation theory for δσ xy (H) to the experimental data. Agreement between the data and the theory beyond H c suggests the survival of the Cooper pair in the insulating region of the SIT.

  3. Memory window engineering of Ta2O5-x oxide-based resistive switches via incorporation of various insulating frames

    Science.gov (United States)

    Lee, Ah Rahm; Baek, Gwang Ho; Kim, Tae Yoon; Ko, Won Bae; Yang, Seung Mo; Kim, Jongmin; Im, Hyun Sik; Hong, Jin Pyo

    2016-07-01

    Three-dimensional (3D) stackable memory frames, including nano-scaled crossbar arrays, are one of the most reliable building blocks to meet the demand of high-density non-volatile memory electronics. However, their utilization has the disadvantage of introducing issues related to sneak paths, which can negatively impact device performance. We address the enhancement of complementary resistive switching (CRS) features via the incorporation of insulating frames as a generic approach to extend their use; here, a Pt/Ta2O5-x/Ta/Ta2O5-x/Pt frame is chosen as the basic CRS cell. The incorporation of Ta/Ta2O5-x/Ta or Pt/amorphous TaN/Pt insulting frames into the basic CRS cell ensures the appreciably advanced memory features of CRS cells including higher on/off ratios, improved read margins, and increased selectivity without reliability degradation. Experimental observations identified that a suitable insulating frame is crucial for adjusting the abrupt reset events of the switching element, thereby facilitating the enhanced electrical characteristics of CRS cells that are suitable for practical applications.

  4. Do clinical examination gloves provide adequate electrical insulation for safe hands-on defibrillation? I: Resistive properties of nitrile gloves.

    Science.gov (United States)

    Deakin, Charles D; Lee-Shrewsbury, Victoria; Hogg, Kitwani; Petley, Graham W

    2013-07-01

    Uninterrupted chest compressions are a key factor in determining resuscitation success. Interruptions to chest compression are often associated with defibrillation, particularly the need to stand clear from the patient during defibrillation. It has been suggested that clinical examination gloves may provide adequate electrical resistance to enable safe hands-on defibrillation in order to minimise interruptions. We therefore examined whether commonly used nitrile clinical examination gloves provide adequate resistance to current flow to enable safe hands-on defibrillation. Clinical examination gloves (Kimberly Clark KC300 Sterling nitrile) worn by members of hospital cardiac arrest teams were collected immediately following termination of resuscitation. To determine the level of protection afforded by visually intact gloves, electrical resistance across the glove was measured by applying a DC voltage across the glove and measuring subsequent resistance. Forty new unused gloves (control) were compared with 28 clinical (non-CPR) gloves and 128 clinical (CPR) gloves. One glove in each group had a visible tear and was excluded from analysis. Control gloves had a minimum resistance of 120 kΩ (median 190 kΩ) compared with 60 kΩ in clinical gloves (both CPR (median 140 kΩ) and non-CPR groups (median 160 kΩ)). Nitrile clinical examination gloves do not provide adequate electrical insulation for the rescuer to safely undertake 'hands-on' defibrillation and when exposed to the physical forces of external chest compression, even greater resistive degradation occurs. Further work is required to identify gloves suitable for safe use for 'hands-on' defibrillation. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. Validation of HOMA-IR in a model of insulin-resistance induced by a high-fat diet in Wistar rats.

    Science.gov (United States)

    Antunes, Luciana C; Elkfury, Jessica L; Jornada, Manoela N; Foletto, Kelly C; Bertoluci, Marcello C

    2016-04-01

    Objective The present study aimed to validate homeostasis model assessment of insulin resistance (HOMA-IR) in relation to the insulin tolerance test (ITT) in a model of insulin-resistance in Wistar rats induced by a 19-week high-fat diet. Materials and methods A total of 30 male Wistar rats weighing 200-300 g were allocated into a high-fat diet group (HFD) (55% fat-enriched chow, ad lib, n = 15) and a standard-diet group (CD) standard chow, ad lib, n = 15), for 19 weeks. ITT was determined at baseline and in the 19th week. HOMA-IR was determined between the 18-19th week in three different days and the mean was considered for analysis. Area under the curve (AUC-ITT) of the blood glucose excursion along 120 minutes after intra-peritoneal insulin injection was determined and correlated with the corresponding fasting values for HOMA-IR. Results AUC-ITT and HOMA-IR were significantly greater after 19th week in HFD compared to CD (p HOMA-IR was strongly correlated (Pearson's) with AUC-ITT r = 0.637; p HOMA-IR and AUC-ITT showed similar sensitivity and specificity. Conclusion HOMA-IR is a valid measure to determine insulin-resistance in Wistar rats. Arch Endocrinol Metab. 2016;60(2):138-42.

  6. Definition of insulin resistance using the homeostasis model assessment (HOMA-IR) in IVF patients diagnosed with polycystic ovary syndrome (PCOS) according to the Rotterdam criteria.

    Science.gov (United States)

    Alebić, Miro Šimun; Bulum, Tomislav; Stojanović, Nataša; Duvnjak, Lea

    2014-11-01

    Polycystic ovary syndrome (PCOS) women are more insulin resistant than general population. Prevalence data on insulin resistance (IR) in PCOS vary depending on population characteristics and methodology used. The objectives of this study were to investigate whether IR in PCOS is exclusively associated with body mass and to assess the prevalence of IR in lean and overweight/obese PCOS. Study included 250 consecutive women who attended a Department of Human Reproduction diagnosed as having PCOS according to the Rotterdam criteria. Control group comprised 500 healthy women referred for male factor infertility evaluation during the same period as the PCOS women. PCOS women (n = 250) were more insulin resistant than controls (n = 500) even after adjustment for age and body mass index (BMI) (P = 0.03). Using logistic regression analysis, BMI ≥ 25 kg/m(2) (OR 6.0; 95 % CI 3.3-11.0), PCOS (OR 2.2; 95 % CI 1.4-3.5) and waist circumference ≥ 80 cm (OR 2.0; 95 % CI 1.1-3.8) were identified as independent determinants of IR (P IR was more prevalent in overweight/obese controls (n = 100) than in lean PCOS women (n = 150), 31 versus 9.3 %, but less prevalent than in overweight/obese PCOS (n = 100), 31 versus 57 %. The prevalence of IR between lean controls (5 %) and lean PCOS (9.3 %) did not significantly differ. Both PCOS-specific and obesity-related IR independently contribute to IR in PCOS. Using HOMA-IR cutoff value of 3.15 specific for Croatian women in our clinical setting, the assessed prevalence of IR in lean and overweight/obese PCOS women was 9.3 and 57 %, respectively.

  7. INSULATION RESISTANCE OF PRINTED CIRCUIT BOARDS. BEHAVIOR OF CERTAIN TYPES AND MAKES UNDER DIFFERENT CLIMATIC CONDITIONS. En undersoegelse af en raekke typer og fabrikater under forskellige klimatiske forhold

    Energy Technology Data Exchange (ETDEWEB)

    Olesen, S. T.

    1971-11-15

    The present study embraces measurements of insulation resistance on a number of types and makes of printed-circuit boards. The insulation measurements were performed on boards just received from the manufacturer, as well as on boards exposed to humidity or to elevated temperatures. A total of 33 types from five different material categories were obtained. The test material used thus originated from a variety of independent sources. The purpose of the project was to investigate the frequency with which batches with insufficiently baked material - and consequently having a poor insulation resistance - were encountered in practice. No such batches were in fact found, and it is likely that they do not occur as often as had previously been assumed.

  8. Induction of resistance to blast disease (Pyricularia oryzae) in the high yielding variety, Ratna (IR8xTKM6)

    International Nuclear Information System (INIS)

    Kaur, S.; Padmanabhan, S.Y.; Kaur, P.

    1977-01-01

    The high yielding variety, Ratna (IR8 x TKM6), susceptible to blast disease (Pyricularia oryzae Cav.), was taken up for induction of resistance to the disease through EMS treatment. The seeds of individual M 1 plants were harvested and grown as M 2 generation in a ''uniform blast nursery''. The scoring and classification of blast reaction was done according to the method described by Padmanabhan and Ganguly. The seeds of ''resistant'' selections and ''susceptible'' selections were harvested, grown and tested again in the ''uniform blast nursery'' for M 3 , M 4 and M 5 generations. Ratna (untreated) developed 'B', 'C', and 'D' type of spots whereas the EMS-treated populations in all generations, i.e. M 2 -M 4 , developed 'O', 'A' and 'E' types of spot, in addition to 'B', 'C' and 'D' types, in both resistant and susceptible selections. This indicated that the chemical mutagen EMS induced variability in both negative and positive directions. In M 5 generation, 50 out of 1500 originally selected lines were found to be breeding true for disease resistance. Some mutants retain the grain characters of Ratna, and the high yield. The mutagen treatment also induced variability in grain characters. Ratna has a long slender grain. Some mutants have medium slender, short bold or long bold grain. (author)

  9. The HOMA-Adiponectin (HOMA-AD) Closely Mirrors the HOMA-IR Index in the Screening of Insulin Resistance in the Brazilian Metabolic Syndrome Study (BRAMS)

    Science.gov (United States)

    Cassani, Roberta Soares Lara; Forti, Adriana Costa e; Pareja, José Carlos; Tambascia, Marcos Antonio; Geloneze, Bruno

    2016-01-01

    Background The major adverse consequences of obesity are associated with the development of insulin resistance (IR) and adiposopathy. The Homeostasis Model Assessment-Adiponectin (HOMA-AD) was proposed as a modified version of the HOMA1-IR, which incorporates adiponectin in the denominator of the index. Objectives To evaluate the performance of the HOMA-AD index compared with the HOMA1-IR index as a surrogate marker of IR in women, and to establish the cutoff value of the HOMA-AD. Subjects/Methods The Brazilian Metabolic Syndrome Study (BRAMS) is a cross-sectional multicenter survey. The data from 1,061 subjects met the desired criteria: 18–65 years old, BMI: 18.5–49.9 Kg/m² and without diabetes. The IR was assessed by the indexes HOMA1-IR and HOMA-AD (total sample) and by the hyperglycemic clamp (n = 49). Metabolic syndrome was defined using the IDF criteria. Results For the IR assessed by the clamp, the HOMA-AD demonstrated a stronger coefficient of correlation (r = -0.64) compared with the HOMA1-IR (r = -0.56); p 0.05). The optimal cutoff identified for the HOMA-AD for the diagnosis of IR was 0.95. Conclusions The HOMA-AD index was demonstrated to be a useful surrogate marker for detecting IR among adult women and presented a similar performance compared with the HOMA1-IR index. These results may assist physicians and researchers in determining which method to use to evaluate IR in light of the available facilities. PMID:27490249

  10. The HOMA-Adiponectin (HOMA-AD Closely Mirrors the HOMA-IR Index in the Screening of Insulin Resistance in the Brazilian Metabolic Syndrome Study (BRAMS.

    Directory of Open Access Journals (Sweden)

    Brunna Sullara Vilela

    Full Text Available The major adverse consequences of obesity are associated with the development of insulin resistance (IR and adiposopathy. The Homeostasis Model Assessment-Adiponectin (HOMA-AD was proposed as a modified version of the HOMA1-IR, which incorporates adiponectin in the denominator of the index.To evaluate the performance of the HOMA-AD index compared with the HOMA1-IR index as a surrogate marker of IR in women, and to establish the cutoff value of the HOMA-AD.The Brazilian Metabolic Syndrome Study (BRAMS is a cross-sectional multicenter survey. The data from 1,061 subjects met the desired criteria: 18-65 years old, BMI: 18.5-49.9 Kg/m² and without diabetes. The IR was assessed by the indexes HOMA1-IR and HOMA-AD (total sample and by the hyperglycemic clamp (n = 49. Metabolic syndrome was defined using the IDF criteria.For the IR assessed by the clamp, the HOMA-AD demonstrated a stronger coefficient of correlation (r = -0.64 compared with the HOMA1-IR (r = -0.56; p 0.05. The optimal cutoff identified for the HOMA-AD for the diagnosis of IR was 0.95.The HOMA-AD index was demonstrated to be a useful surrogate marker for detecting IR among adult women and presented a similar performance compared with the HOMA1-IR index. These results may assist physicians and researchers in determining which method to use to evaluate IR in light of the available facilities.

  11. Deltamethrin-resistant German Cockroaches Are Less Sensitive to the Insect Repellents DEET and IR3535 than Non-resistant Individuals.

    Science.gov (United States)

    Mengoni, Sofía L; Alzogaray, Raúl A

    2018-04-02

    The German cockroach, Blattella germanica (L.) (Blattodea: Blattellidae), is a serious worldwide pest with a considerable economical and sanitary impact. It is mainly controlled by the application of synthetic insecticides, but repeated use of these substances has promoted the appearance of resistance in cockroach populations throughout the world. The aim of this study was to compare the behavior of deltamethrin-susceptible (CIPEIN colony) and deltamethrin-resistant (JUBA and VGBA colonies) first instar nymphs exposed to the repellents N,N-diethyl-3-methylbenzamide (DEET) and ethyl 3-[acetyl(butyl)amino]propanoate (IR3535). Firstly, the behavior of the nymphs was assessed in an experimental arena in the absence of repellents. The parameters Distance Traveled, Velocity, Mobility Time, and Time Spent (in each half of the arena) were quantified using an image analyser, and showed that the behavior elicited by the three colonies was similar. After this, the behavior of the nymphs was quantified in an arena, half of which had been treated with repellent. The repellency of DEET increased as a linear function of log concentration for the three colonies. DEET elicited repellency as from a concentration of 97.49 µg/cm2 for the CIPEIN and JUBA colonies and 194.98 µg/cm2 for the VGBA colony. The repellency of IR3535 was weaker and started at a concentration of 389.96 µg/cm2 for the CIPEIN colony, 779.92 μg/cm2 for JUBA, and 1559.84 μg/cm2 for VGBA . Finally, nymphs were exposed to 3:1, 1:1, and 1:3 DEET:IR3535 mixtures, and a synergistic effect was observed only in the CIPEIN colony.

  12. Tanshinone I alleviates insulin resistance in type 2 diabetes mellitus rats through IRS-1 pathway.

    Science.gov (United States)

    Wei, Ying; Gao, Jiaqi; Qin, Lingling; Xu, Yunling; Wang, Dongchao; Shi, Haoxia; Xu, Tunhai; Liu, Tonghua

    2017-09-01

    Tanshinone I from tanshen has been used in traditional Chinese medicine for treating cardiovascular diseases and inflammatory diseases. Given the link between inflammation and Type 2 diabetes mellitus (T2DM), we suspect that tanshinone I may have a beneficial effect on T2DM. This study was to investigate the potential effects of tanshinone I on T2DM and its underlying mechanism. T2DM was thus induced in Sprague-Dawley (SD) rats using streptozotocin (STZ) and high-fat diet. It was observed that T2DM rats had higher levels of total cholesterol (TC), nonesterified fatty acids (NEFAs), total triglyceride (TG) and total low density lipoprotein cholesterol (LDL-C) compared with normal, healthy SD rats. Treatment with tanshinone I decreased these levels and lowered blood glucose level in T2DM rats. In addition, enzyme-linked immunosorbent assay (ELISA) analysis showed that T2DM rats had elevated levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Furthermore, Western blot analysis revealed that T2DM rats had enhanced nuclear translocation of NF-κB as well as elevated phosphorylation of Ser307 in IRS-1(insulin receptor substrate 1). Treatment by tanshinone I lowered the levels of IL-6 and TNF-α, decreased nuclear translocation of NF-κB as well as phosphorylation of Ser307 in IRS-1. These results demonstrated that tanshinone I could alleviate T2DM syndrome in rats. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  13. Semi-insulating Sn-Zr-O: Tunable resistance buffer layers

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Teresa M.; Burst, James M.; Reese, Matthew O.; Perkins, Craig L. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

    2015-03-02

    Highly resistive and transparent (HRT) buffer layers are critical components of solar cells and other opto-electronic devices. HRT layers are often undoped transparent conducting oxides. However, these oxides can be too conductive to form an optimal HRT. Here, we present a method to produce HRT layers with tunable electrical resistivity, despite the presence of high concentrations of unintentionally or intentionally added dopants in the film. This method relies on alloying wide-bandgap, high-k dielectric materials (e.g., ZrO{sub 2}) into the host oxide to tune the resistivity. We demonstrate Sn{sub x}Zr{sub 1−x}O{sub 2}:F films with tunable resistivities varying from 0.001 to 10 Ω cm, which are controlled by the Zr mole fraction in the films. Increasing Zr suppresses carriers by expanding the bandgap almost entirely by shifting the valence-band position, which allows the HRT layers to maintain good conduction-band alignment for a low-resistance front contact.

  14. Insulin resistance (HOMA-IR) cut-off values and the metabolic syndrome in a general adult population: effect of gender and age: EPIRCE cross-sectional study.

    Science.gov (United States)

    Gayoso-Diz, Pilar; Otero-González, Alfonso; Rodriguez-Alvarez, María Xosé; Gude, Francisco; García, Fernando; De Francisco, Angel; Quintela, Arturo González

    2013-10-16

    Insulin resistance has been associated with metabolic and hemodynamic alterations and higher cardio metabolic risk. There is great variability in the threshold homeostasis model assessment of insulin resistance (HOMA-IR) levels to define insulin resistance. The purpose of this study was to describe the influence of age and gender in the estimation of HOMA-IR optimal cut-off values to identify subjects with higher cardio metabolic risk in a general adult population. It included 2459 adults (range 20-92 years, 58.4% women) in a random Spanish population sample. As an accurate indicator of cardio metabolic risk, Metabolic Syndrome (MetS), both by International Diabetes Federation criteria and by Adult Treatment Panel III criteria, were used. The effect of age was analyzed in individuals with and without diabetes mellitus separately. ROC regression methodology was used to evaluate the effect of age on HOMA-IR performance in classifying cardio metabolic risk. In Spanish population the threshold value of HOMA-IR drops from 3.46 using 90th percentile criteria to 2.05 taking into account of MetS components. In non-diabetic women, but no in men, we found a significant non-linear effect of age on the accuracy of HOMA-IR. In non-diabetic men, the cut-off values were 1.85. All values are between 70th-75th percentiles of HOMA-IR levels in adult Spanish population. The consideration of the cardio metabolic risk to establish the cut-off points of HOMA-IR, to define insulin resistance instead of using a percentile of the population distribution, would increase its clinical utility in identifying those patients in whom the presence of multiple metabolic risk factors imparts an increased metabolic and cardiovascular risk. The threshold levels must be modified by age in non-diabetic women.

  15. Longitudinal associations of lifestyle factors and weight status with insulin resistance (HOMA-IR) in preadolescent children: the large prospective cohort study IDEFICS.

    Science.gov (United States)

    Peplies, Jenny; Börnhorst, Claudia; Günther, Kathrin; Fraterman, Arno; Russo, Paola; Veidebaum, Toomas; Tornaritis, Michael; De Henauw, Stefaan; Marild, Staffan; Molnar, Dénes; Moreno, Luis A; Ahrens, Wolfgang

    2016-09-02

    This study investigates prospective associations of anthropometrical and lifestyle indices with insulin resistance (IR) in European children from the IDEFICS cohort. Insulin resistance (IR) is a growing concern in childhood obesity and a central aspect of the metabolic syndrome (MS). It most likely represents the link between obesity and type 2 diabetes. This longitudinal study included 3348 preadolescent children aged 3 to 10.9 years from 8 European countries who were observed from 2007/2008 to 2009/2010. The main outcome measure in the present analysis is HOMA-IR (homeostasis model assessment as a common proxy indicator to quantify IR) at follow-up and in its longitudinal development. Anthropometrical measures and lifestyle indices, including objectively determined physical activity, were considered, among others factors, as determinants of IR. Prospective associations between IR at follow-up and anthropometrical and lifestyle indices were estimated by logistic regression models. Country-specific prevalence rates of IR in the IDEFICS cohort of European children showed a positive trend with weight category. Prospective multivariate analyses showed the strongest positive associations of IR with BMI z-score (OR = 2.6 for unit change from the mean, 95 % CI 2.1-3.1) and z-score of waist circumference (OR = 2.2 for unit change from the mean, 95 % CI 1.9-2.6), which were analysed in separate models, but also for sex (OR = 2.2 for girls vs. boys, 95 % CI 1.5-3.1 up to OR 2.5, 95 % CI 1.8-3.6 depending on the model), audio-visual media time (OR = 1.2 for an additional hour per day, 95 % CI 1.0-1.4 in both models) and an inverse association of objectively determined physical activity (OR = 0.5 for 3(rd) compared to 1(st) quartile, 95 % CI 0.3-0.9 in both models). A longitudinal reduction of HOMA-IR was accompanied with a parallel decline in BMI. This study is, to our knowledge, the first prospective study on IR in a preadolescent children

  16. Density of interface states, excess capacitance and series resistance in the metal-insulator-semiconductor (MIS) solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Altindal, Semsettin; Tataroglu, Adem; Dokme, Ilbilge [Faculty of Arts and Sciences, Physics Department, Gazi University, 06500, Ankara (Turkey)

    2005-01-31

    Dark and illuminated current-voltage (I-V) characteristics of Al/SiO{sub x}/p-Si metal-insulator-semiconductor (MIS) solar cells were measured at room temperature. In addition to capacitance-voltage (C-V) and conductance-voltage (G-V), characteristics are studied at a wide frequency range of 1kHz-10MHz. The dark I-V characteristics showed non-ideal behavior with an ideal factor of 3.2. The density of interface states distribution profiles as a function of (E{sub ss}-E{sub v}) deduced from the I-V measurements at room temperature for the MIS solar cells on the order of 10{sup 13}cm{sup -2}eV{sup -1}. These interface states were responsible for the non-ideal behavior of I-V, C-V and G-V characteristics. Frequency dispersion in capacitance for MIS solar cells can be interpreted only in terms of interface states. The interface states can follow the a.c. signal and yield an excess capacitance, which depends on the relaxation time of interface states and the frequency of the a.c. signal. It was observed that the excess capacitance C{sub o} caused by an interface state decreases with an increase of frequency. The capacitances characteristics of MIS solar cells are affected not only in interface states but also series resistance. Analysis of this data indicated that the high interface states and series resistance leads to lower values of open-circuit voltage, short-circuit current density, and fill factor. Experimental results show that the location of interface states and series resistance have a significant effect on I-V, C-V and G-V characteristics.

  17. Effect of H{sup +} implantation on the optical properties of semi-insulating GaAs crystals in the IR spectral region

    Energy Technology Data Exchange (ETDEWEB)

    Klyui, N. I.; Lozinskii, V. B., E-mail: lvb@isp.kiev.ua [Jilin University, College of Physics (China); Liptuga, A. I.; Dikusha, V. N. [National Academy of Sciences of Ukraine, Lashkaryov Institute of Semiconductor Physics (Ukraine); Oksanych, A. P.; Kogdas’, M. G.; Perekhrest, A. L.; Pritchin, S. E. [Kremenchug National University (Ukraine)

    2017-03-15

    The optical properties of semi-insulating GaAs crystals subjected to multienergy hydrogen-ion implantation and treatment in a high-frequency electromagnetic field are studied in the infrared spectral region. It is established that such combined treatment provides a means for substantially increasing the transmittance of GaAs crystals to values characteristic of crystals of high optical quality. On the basis of analysis of the infrared transmittance and reflectance data, Raman spectroscopy data, and atomic-force microscopy data on the surface morphology of the crystals, a physical model is proposed to interpret the effects experimentally observed in the crystals. The model takes into account the interaction of radiation defects with the initial structural defects in the crystals as well as the effect of compensation of defect centers by hydrogen during high-frequency treatment.

  18. Effect of H+ implantation on the optical properties of semi-insulating GaAs crystals in the IR spectral region

    International Nuclear Information System (INIS)

    Klyui, N. I.; Lozinskii, V. B.; Liptuga, A. I.; Dikusha, V. N.; Oksanych, A. P.; Kogdas’, M. G.; Perekhrest, A. L.; Pritchin, S. E.

    2017-01-01

    The optical properties of semi-insulating GaAs crystals subjected to multienergy hydrogen-ion implantation and treatment in a high-frequency electromagnetic field are studied in the infrared spectral region. It is established that such combined treatment provides a means for substantially increasing the transmittance of GaAs crystals to values characteristic of crystals of high optical quality. On the basis of analysis of the infrared transmittance and reflectance data, Raman spectroscopy data, and atomic-force microscopy data on the surface morphology of the crystals, a physical model is proposed to interpret the effects experimentally observed in the crystals. The model takes into account the interaction of radiation defects with the initial structural defects in the crystals as well as the effect of compensation of defect centers by hydrogen during high-frequency treatment.

  19. Resistência insulínica pode prejudicar a redução da espessura mediointimal em adolescentes obesos

    Directory of Open Access Journals (Sweden)

    Priscila de Lima Sanches

    2012-10-01

    Full Text Available FUNDAMENTO: O processo aterosclerótico no nível endotelial começa em idade precoce e parece estar associado com a obesidade e suas comorbidades como a resistência insulínica. OBJETIVO: O objetivo deste estudo foi verificar a influência da resistência insulínica em marcadores inflamatórios e subclínicos de aterosclerose em adolescentes obesos. MÉTODOS: Sessenta e seis adolescentes obesos pós-púberes foram divididos em dois grupos de acordo com o índice de resistência insulínica estimado pelo Modelo de Avaliação da Homeostase (HOMA-RI: com resistência insulínica (RI n = 39 e sem resistência insulínica (NRI n = 27, e foram submetidos a uma intervenção interdisciplinar ao longo de um ano. A espessura mediointimal da artéria carótida comum (EMIC, e o tecido adiposo visceral e subcutâneo foram determinados por ultrassonografia. A composição corporal, pressão arterial, índice HOMA-RI, perfil lipídico e as concentrações de adipocinas [leptina, adiponectina, e inibidor do ativador do plasminogênio-1 (PAI-1] foram analisados antes e após a terapia. RESULTADOS: Ambos os grupos apresentaram melhoras significativas na composição corporal, estado inflamatório (redução da concentração de leptina e PAI 1; aumento de adiponectina plasmática e redução da EMIC. Apenas o grupo NRI mostrou correlação positiva entre as alterações na gordura visceral (∆Visceral e mudanças na EMIC (∆ EMIC (r = 0,42, p < 0,05. A análise por regressão linear simples revelou o ∆Visceral ser um preditor independente para a redução da EMIC nesse grupo (R2 ajustado = 0,14, p = 0,04. Os valores finais da EIMC permaneceram significativamente maiores no grupo RI, quando comparado com grupo NRI. CONCLUSÃO: A presença de resistência insulínica pode prejudicar mudanças na EMIC levando ao desenvolvimento precoce da aterosclerose em adolescentes obesos submetidos a uma intervenção interdisciplinar.

  20. Clinical and Biochemical Profiles according to Homeostasis Model Assessment-insulin Resistance (HOMA-IR) in Korean Women with Polycystic Ovary Syndrome.

    Science.gov (United States)

    Lee, Da Eun; Park, Soo Yeon; Park, So Yun; Lee, Sa Ra; Chung, Hye Won; Jeong, Kyungah

    2014-12-01

    The aim of this study was to investigate the clinical and biochemical profiles according to homeostasis model assessment of insulin resistance (HOMA-IR) in Korean polycystic ovary syndrome (PCOS) patients. In 458 PCOS patients diagnosed by the Rotterdam European Society for Human Reproduction and Embryology (ESHRE) criteria, measurements of somatometry, blood test of hormones, glucose metabolic and lipid profiles, and transvaginal or transrectal ultrasonogram were carried out. HOMA-IR was then calculated and compared with the clinical and biochemical profiles related to PCOS. The patients were divided into 4 groups by quartiles of HOMA-IR. The mean level of HOMA-IR was 2.18 ± 1.73. Among the four groups separated according to HOMA-IR, body weight, body mass index (BMI), waist-to-hip ratio (WHR), triglyceride (TG), total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, lipid accumulation product (LAP) index, high-sensitivity C-reactive protein (hs-CRP), Apoprotein B, free testosterone, and sex hormone binding globulin (SHBG) were found to be significantly different. TG, LAP index, glucose metabolic profiles, and hs-CRP were positively correlated with HOMA-IR after adjustment for BMI. Our results suggest that the clinical and biochemical profiles which are applicable as cardiovascular risk factors are highly correlated with HOMA-IR in Korean women with PCOS.

  1. Research on vacuum insulation for cryocables

    International Nuclear Information System (INIS)

    Graneau, P.

    1974-01-01

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

  2. Fasting serum insulin and the homeostasis model of insulin resistance (HOMA-IR) in the monitoring of lifestyle interventions in obese persons.

    Science.gov (United States)

    Vogeser, Michael; König, Daniel; Frey, Ingrid; Predel, Hans-Georg; Parhofer, Klaus Georg; Berg, Aloys

    2007-09-01

    Lifestyle changes with increased physical activity and balanced energy intake are recognized as the principal interventions in obesity and insulin resistance. Only few prospective studies, however, have so far addressed the potential role of routine biochemical markers of insulin sensitivity in the monitoring of respective interventions. Fasting insulin and glucose was measured in 33 obese individuals undergoing a lifestyle modification program (MOBILIS) at baseline and after 1 year. The HOMA-IR index (homeostasis model of insulin resistance) was calculated as [fasting serum glucose*fasting serum insulin/22.5], with lower values indicating a higher degree of insulin sensitivity. While the median body mass index (BMI) and waist circumference decreased by 10% and 11%, respectively, the HOMA-IR index decreased in an over-proportional manner by 45% within 1 year (BMI baseline, median 35.7, interquartile range (IQR) 33.7-37.7; after 1 year, median 32.2, IQR 29.6-35.1. HOMA-IR baseline, median 2.9, IQR 1.5-4.6; after 1 year 1.6, IQR 0.9-2.7). In contrast to HOMA-IR and fasting serum insulin, no significant changes in fasting serum glucose were observed. Baseline and post-intervention HOMA-IR showed a high degree of inter-individual variation with eight individuals maintaining high HOMA-IR values despite weight loss after 1 year of intervention. Individual changes in the carbohydrate metabolism achieved by a lifestyle intervention program were displayed by fasting serum insulin concentrations and the HOMA-IR but not by fasting glucose measurement alone. Therefore, assessment of the HOMA-IR may help to individualize lifestyle interventions in obesity and to objectify improvements in insulin sensitivity after therapeutic lifestyle changes.

  3. Dependence of temperature-dependent electrical resistivity of SrIrO3 on hydrostatic pressure to 9.1 kbar

    International Nuclear Information System (INIS)

    Foroozani, N.; Lim, J.; Li, L.; Cao, G.; Schilling, J.S.

    2013-01-01

    Non-Fermi-liquid behavior and close proximity to a quantum critical point in the 5d transition metal iridate SrIrO 3 at ambient pressure motivate our search for possible anomalous behavior in its transport properties under pressure. The electrical resistivity in the ab-plane of a single crystal of SrIrO 3 has been measured over the temperature range 1.35–285 K at both ambient and 9.1 kbar hydrostatic pressure. The resistivity decreases slightly over the entire temperature range, but no superconducting transition or changes in the non-Fermi-liquid behavior are observed under pressure. It is estimated that significantly higher pressures are likely required before sizable changes in the properties of SrIrO 3 will occur.

  4. Relationship of visfatin level to pancreatic endocrine hormone level, HOMA-IR index, and HOMA β-cell index in overweight women who performed hydraulic resistance exercise

    OpenAIRE

    Ha, Chang Ho; Swearingin, Brenda; Jeon, Yong Kyun

    2015-01-01

    [Purpose] This study aimed to examine the correlation of visfatin level to pancreatic endocrine hormone level, homeostasis model assessment of insulin resistance (HOMA-IR) index, and HOMA β-cell index in hydraulic resistance exercise. Furthermore, it investigated the relationship between visfatin level and other variables affected by exercise in overweight women. [Subjects and Methods] The exercise group trained for 12 weeks, 70 minutes/day, 5 days/week. Visfatin level, pancreatic endocrine h...

  5. Analysis of surface insulation resistance related failures in electronics by circuit simulation

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Joshy, Salil; Jellesen, Morten Stendahl

    2017-01-01

    conduction medium. Findings-This paper provides a summary of the effects of contamination with various weak organic acids representing the active components in no-clean solder flux residue, and demonstrates the effect of humidity and contamination on the possible malfunctions and errors in electronic...... of the circuits using a range of empirical leakage resistance values combined with the knowledge of the humidity and contamination profile of the electronics can be used for the robust design of a device, which is also important for electronic products relying on low current consumption for long battery lifetime....... Originality/value-Examples provide a basic link between the combined effect of humidity and contamination and the performance of electronic circuits. The methodology shown provides the possibility of addressing the climatic reliability of an electronic device at the early stage of device design by using...

  6. Relationship between high white blood cell count and insulin resistance (HOMA-IR) in Korean children and adolescents: Korean National Health and Nutrition Examination Survey 2008-2010.

    Science.gov (United States)

    Park, J-M; Lee, D-C; Lee, Y-J

    2017-05-01

    Increasing evidence has indicated that insulin resistance is associated with inflammation. However, few studies have investigated the association between white blood cell (WBC) count and insulin resistance, as measured by a homeostasis model assessment of insulin resistance (HOMA-IR) in a general pediatric population. This study aimed to examine the association between WBC count and insulin resistance as measured by HOMA-IR in a nationally representative sample of children and adolescents. In total, 2761 participants (1479 boys and 1282 girls) aged 10-18 years were selected from the 2008-2010 Korean National Health and Nutrition Examination Survey. Insulin resistance was defined as a HOMA-IR value greater than the 90th percentile. The odds ratios and 95% confidence intervals for insulin resistance were determined using multiple logistic regression analysis. The mean values of most cardiometabolic variables tended to increase proportionally with WBC count quartiles. The prevalence of insulin resistance significantly increased in accordance with WBC count quartiles in both boys and girls. Compared to individuals in the lowest WBC count quartile, the odds ratio for insulin resistance for individuals in the highest quartile was 2.84 in boys and 3.20 in girls, after adjusting for age, systolic blood pressure, body mass index, and waist circumference. A higher WBC count was positively associated with an increased risk of insulin resistance in Korean children and adolescents. This study suggests that WBC count could facilitate the identification of children and adolescents with insulin resistance. Copyright © 2017 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

  7. High Voltage Resistive Divider Based on Cast Microwire in Glass Insulation on 6–24 kV Alternating Current of Commercial Frequency.

    Directory of Open Access Journals (Sweden)

    Juravleov A.

    2008-12-01

    Full Text Available It is presented the analysis and description of the construction of the high voltage resistive divider on the base of cast microwire in glass insulation on 6–24 kV alternating current of commercial frequency. It is presented the procedure of compensation of frequency error during the process of fabrication of divides and results of tests of the sample model of the divider as well.

  8. Meta-analyses of the Association of Sleep Apnea with Insulin Resistance, and the Effects of CPAP on HOMA-IR, Adiponectin, and Visceral Adipose Fat.

    Science.gov (United States)

    Iftikhar, Imran H; Hoyos, Camilla M; Phillips, Craig L; Magalang, Ulysses J

    2015-04-15

    We sought to conduct an updated meta-analysis of randomized controlled trials (RCTs) on the effect of continuous positive airway pressure (CPAP) on insulin resistance, as measured by homeostasis model assessment of insulin resistance (HOMA-IR), visceral abdominal fat (VAF), and adiponectin. Additionally, we performed a separate meta-analysis and meta-regression of studies on the association of insulin resistance and obstructive sleep apnea (OSA). All included studies were searched from PubMed (from conception to March 15, 2014). Data were pooled across all included RCTs as the mean difference in HOMA-IR and VAF, and as the standardized mean difference in the case of adiponectin analysis. From the included case-control studies, data on the difference of HOMA-IR between cases and controls were pooled across all studies, as the standardized mean difference (SMD). There was a significant difference in HOMA-IR (-0.43 [95% CIs: -0.75 to -0.11], p = 0.008) between CPAP treated and non CPAP treated participants. However, there was no significant difference in VAF or adiponectin; (-47.93 [95% CI: -112.58 to 16.72], p = 0.14) and (-0.06 [95% CI: -0.28 to 0.15], p = 0.56), respectively. Meta-analysis of 16 case-control studies showed a pooled SMD in HOMA-IR of 0.51 (95% CI: 0.28 to 0.75), p ≤ 0.001, between cases and controls. The results of our meta-analyses show that CPAP has a favorable effect on insulin resistance. This effect is not associated with any significant changes in total adiponectin levels or amount of VAF. Our findings also confirm a significant association between OSA and insulin resistance. © 2015 American Academy of Sleep Medicine.

  9. Evaluation of fasting plasma insulin concentration as an estimate of insulin action in nondiabetic individuals: comparison with the homeostasis model assessment of insulin resistance (HOMA-IR).

    Science.gov (United States)

    Abbasi, Fahim; Okeke, QueenDenise; Reaven, Gerald M

    2014-04-01

    Insulin-mediated glucose disposal varies severalfold in apparently healthy individuals, and approximately one-third of the most insulin resistant of these individuals is at increased risk to develop various adverse clinical syndromes. Since direct measurements of insulin sensitivity are not practical in a clinical setting, several surrogate estimates of insulin action have been proposed, including fasting plasma insulin (FPI) concentration and the homeostasis model assessment of insulin resistance (HOMA-IR) calculated by a formula employing fasting plasma glucose (FPG) and FPI concentrations. The objective of this study was to compare FPI as an estimate of insulin-mediated glucose disposal with values generated by HOMA-IR in 758 apparently healthy nondiabetic individuals. Measurements were made of FPG, FPI, triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C) concentrations, and insulin-mediated glucose uptake was quantified by determining steady-state plasma glucose (SSPG) concentration during the insulin suppression test. FPI and HOMA-IR were highly correlated (r = 0.98, P HOMA-IR (r = 0.64). Furthermore, the relationship between FPI and TG (r = 0.35) and HDL-C (r = -0.40) was comparable to that between HOMA-IR and TG (r = 0.39) and HDL-C (r = -0.41). In conclusion, FPI and HOMA-IR are highly correlated in nondiabetic individuals, with each estimate accounting for ~40% of the variability (variance) in a direct measure of insulin-mediated glucose disposal. Calculation of HOMA-IR does not provide a better surrogate estimate of insulin action, or of its associated dyslipidemia, than measurement of FPI.

  10. Estimation of insulin resistance in non-diabetic normotensive Saudi adults by QUICKI, HOMA-IR and modified QUICKI: a comparative study.

    Science.gov (United States)

    Bahijri, Suhad M; Alissa, Eman M; Akbar, Daad H; Ghabrah, Tawfik M

    2010-01-01

    Identification of insulin resistance (IR) in the general population is important for developing strategies to reduce the prevalence of non-insulin-dependent diabetes mellitus (NIDDM). We used the original and a modified version of the Quantitative Insulin Sensitivity Check Index (QUICKI, M-QUICKI), and the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) to divide non-diabetic normotensive adults into high- (HIR) and low-insulin-resistant (LIR) subgroups to investigate similarities and differences in their characteristics. Three hundred fifty-seven healthy adults aged 18-50 years were recruited randomly from health centers in Jeddah in a cross-sectional study design. Anthropometric and demographic information was taken. Insulin, glucose, lipid profile and free fatty acid were determined in fasting blood samples. M-QUICKI, HOMA-IR and QUICKI were calculated. Reported cut-off points were used to identify HIR subjects, who were then matched for age and sex to others in the study population, resulting in 3 HIR and 3 LIR subgroups. Two hundred nine subjects satisfied the selection criteria. M-QUICKI correlated significantly (P=.01) with HOMA-IR and QUICKI values. Increased adiposity was the common characteristic of the three HIR subgroups. HIR subgroups identified using M-QUICKI (97 subjects) and HOMA (25 subjects), but not QUICKI (135 subjects), had statistically different biochemical characteristics compared to corresponding LIR sub-groups. Adiposity, but not sex, is a risk factor for IR in the studied population. Further studies are needed to choose the most appropriate index for detecting IR in community-based surveys.

  11. The correlation of the results of capacitance mapping and of sheet resistance mapping in semi-insulating 6H-SiC

    International Nuclear Information System (INIS)

    Lin Shenghuang; Chen Zhiming; Liang Peng; Jiang Dong; Xie Huajie; Yang Ying

    2010-01-01

    A combination of complex surface capacitance mapping and sheet resistance mapping is applied to establish the origin of resistance variations on semi-insulating (SI) 6H-SiC substrates. The direct correlation between the capacitance quadrature and the sheet resistance is found in vanadium-doped SI samples. Regions with low capacitance quadrature show high sheet resistance. This indicates, associated with the nonhomogeneity of sheet resistance on the substrate, that the quality of crystallization is not good enough, which also leads to resistivity nonhomogeneity when comparing with different types of deep defects. According to the capacitance mapping, the region with bad crystallization quality has a high radio absorption coefficient. Another correlation is established between the capacitance in-phase and sheet resistance for the vanadium-doped sample. In this sample, the capacitance in-phase map shows not only the surface topography, but also the same distribution trend as the sheet resistance, namely, regions of high capacitance in-phase reveal high sheet resistance.

  12. Analysis of interface states and series resistance for Al/PVA:n-CdS nanocomposite metal-semiconductor and metal-insulator-semiconductor diode structures

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Mamta; Tripathi, S.K. [Panjab University, Centre of Advanced Study in Physics, Department of Physics, Chandigarh (India)

    2013-11-15

    This paper presents the fabrication and characterization of Al/PVA:n-CdS (MS) and Al/Al{sub 2}O{sub 3}/PVA:n-CdS (MIS) diode. The effects of interfacial insulator layer, interface states (N{sub ss}) and series resistance (R{sub s}) on the electrical characteristics of Al/PVA:n-CdS structures have been investigated using forward and reverse bias I-V, C-V, and G/w-V characteristics at room temperature. Al/PVA:n-CdS diode is fabricated with and without insulator Al{sub 2}O{sub 3} layer to explain the effect of insulator layer on main electrical parameters. The values of the ideality factor (n), series resistance (R{sub s}) and barrier height ({phi} {sub b}) are calculated from ln(I) vs. V plots, by the Cheung and Norde methods. The energy density distribution profile of the interface states is obtained from the forward bias I-V data by taking into account the bias dependence ideality factor (n(V)) and effective barrier height ({phi} {sub e}) for MS and MIS diode. The N{sub ss} values increase from mid-gap energy of CdS to the bottom of the conductance band edge for both MS and MIS diode. (orig.)

  13. Cooper Pairs in Insulators?

    International Nuclear Information System (INIS)

    Valles, James

    2008-01-01

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

  14. Insulin resistance index (HOMA-IR) in the differentiation of patients with non-alcoholic fatty liver disease and healthy individuals.

    Science.gov (United States)

    Salgado, Ana Lúcia Farias de Azevedo; Carvalho, Luciana de; Oliveira, Ana Claudia; Santos, Virgínia Nascimento dos; Vieira, Jose Gilberto; Parise, Edison Roberto

    2010-01-01

    Due to its good correlation to glycemic clamp, HOMA-IR has been widely utilized as insulin resistance index in clinical and epidemiological studies involving non-alcoholic fatty liver disease carriers. However, values used for this parameter have shown large variability. To identify the HOMA-IR cut value that best distinguishes non-diabetic non-alcoholic fatty liver disease patients from a control group. One hundred sixteen non-alcoholic fatty liver disease patients were studied, diagnosed by clinical, biochemical, and liver image or biopsy criteria, and 88 healthy individuals, without any liver disease and testing for oral glucose tolerance within normality. These groups did not differ in age and gender. All were submitted to oral glucose tolerance test and blood samples were collected for glucose and insulin measurements by immunofluorometric method. HOMA-IR was calculated according to the formula: fasting insulin (microU/L) x fasting glucose (nmol/L)/22.5. NAFLD patients showed higher insulin, glycemia, and HOMA-IR values than control group, even when excluding glucose intolerant and diabetes mellitus patients by their glycemic curves. HOMA-IR 75th percentile for control group was 1.78 and the best area under the curve index was obtained for HOMA-IR values of 2.0 [AUC= 0.840 (0.781-0.899 CI 95%), sensitivity (Se): 85%, specificity (Sp): 83%] while value 2.5 showed best specificity without important loss in sensitivity [AUC=0,831 (0.773-0.888) Se = 72%, Sp = 94%]. HOMA-IR values above or equal to 2.0 or 2.5 show enhanced diagnostic value in distinguishing non-alcoholic fatty liver disease carriers from control group individuals.

  15. The effects of a 2 week modified high intensity interval training program on the homeostatic model of insulin resistance (HOMA-IR) in adults with type 2 diabetes.

    Science.gov (United States)

    Shaban, N; Kenno, K A; Milne, K J

    2014-04-01

    High intensity interval training (HIIT) induces similar metabolic adaptations to traditional steady state aerobic exercise training. Until recently, most HIIT studies have examined maximum efforts in healthy populations. The current study aimed to examine the effects of a 2 week modified HIIT program on the homeostatic model of insulin resistance (HOMA-IR) in individuals with type 2 diabetes (T2D). It was hypothesized that HIIT would improve HOMA-IR. Nine individuals with T2D (age=40.2±9.7 y; BMI=33.9±5.3; fasting plasma glucose [FPG]=8.7±2.9 mmol/L; HbA1C=7.3±1.2%; [mean±SD]) performed 6 individualized training sessions of HIIT (4x30 seconds at 100% of estimated maximum workload followed by 4 minutes of active rest) over 2 weeks. HOMA-IR was calculated from FPG and serum insulin and compared against a prior 2 week baseline period. Blood glucose was reduced immediately after each HIIT session (PHOMA-IR were unchanged after training. However, 6 of the 9 individuals exhibited reduced HOMA-IR values after the training period and there was a significant negative correlation between HOMA-IR value prior to training and change in HOMA-IR after HIIT. These observations tend to support the positive health benefits of HITT for individuals with T2D reported in recently published data using a modified HIIT protocol. However, they suggest that the magnitude of the disease should be assessed when examining the effects of exercise interventions in individuals with T2D.

  16. Identification of Quercus agrifolia (coast live oak resistant to the invasive pathogen Phytophthora ramorum in native stands using Fourier-transform infrared (FT-IR spectroscopy

    Directory of Open Access Journals (Sweden)

    Anna Olivia Conrad

    2014-10-01

    Full Text Available Over the last two decades coast live oak (CLO dominance in many California coastal ecosystems has been threatened by the alien invasive pathogen Phytophthora ramorum, the causal agent of sudden oak death. In spite of high infection and mortality rates in some areas, the presence of apparently resistant trees has been observed, including trees that become infected but recover over time. However, identifying resistant trees based on recovery alone can take many years. The objective of this study was to determine if Fourier-transform infrared (FT-IR spectroscopy, a chemical fingerprinting technique, can be used to identify CLO resistant to P. ramorum prior to infection. Soft independent modeling of class analogy identified spectral regions that differed between resistant and susceptible trees. Regions most useful for discrimination were associated with carbonyl group vibrations. Additionally, concentrations of two putative phenolic biomarkers of resistance were predicted using partial least squares regression; > 99% of the variation was explained by this analysis. This study demonstrates that chemical fingerprinting can be used to identify resistance in a natural population of forest trees prior to infection with a pathogen. FT-IR spectroscopy may be a useful approach for managing forests impacted by sudden oak death, as well as in other situations where emerging or existing forest pests and diseases are of concern.

  17. The Usefulness of Homeostatic Measurement Assessment-Insulin Resistance (HOMA-IR) for Detection of Glucose Intolerance in Thai Women of Reproductive Age with Polycystic Ovary Syndrome.

    Science.gov (United States)

    Wongwananuruk, Thanyarat; Rattanachaiyanont, Manee; Leerasiri, Pichai; Indhavivadhana, Suchada; Techatraisak, Kitirat; Angsuwathana, Surasak; Tanmahasamut, Prasong; Dangrat, Chongdee

    2012-01-01

    Objectives. To study the cut-off point of Homeostatic Measurement Assessment-Insulin Resistance (HOMA-IR) as a screening test for detection of glucose intolerance in Thai women with polycystic ovary syndrome (PCOS). Study Design. Cross-sectional study. Setting. Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital. Subject. Two hundred and fifty Thai PCOS women who attended the Gynecologic Endocrinology Unit, during May 2007 to January 2009. Materials and Methods. The paitents were interviewed and examined for weight, height, waist circumference, and blood pressure. Venous blood samples were drawn twice, one at 12-hour fasting and the other at 2 hours after glucose loading. Results. The prevalence of glucose intolerance in Thai PCOS women was 20.0%. The mean of HOMA-IR was 3.53  ±  7.7. Area under an ROC curve for HOMA-IR for detecting glucose intolerance was 0.82. Using the cut-off value of HOMA-IR >2.0, there was sensitivity at 84.0%, specificity at 61.0%, positive predictive value at 35.0%, negative predictive value at 93.8%, and accuracy at 65.6%. Conclusion. HOMA-IR >2.0 was used for screening test for glucose intolerance in Thai PCOS women. If the result was positive, a specific test should be done to prove the diagnosis.

  18. The Usefulness of Homeostatic Measurement Assessment-Insulin Resistance (HOMA-IR for Detection of Glucose Intolerance in Thai Women of Reproductive Age with Polycystic Ovary Syndrome

    Directory of Open Access Journals (Sweden)

    Thanyarat Wongwananuruk

    2012-01-01

    Full Text Available Objectives. To study the cut-off point of Homeostatic Measurement Assessment-Insulin Resistance (HOMA-IR as a screening test for detection of glucose intolerance in Thai women with polycystic ovary syndrome (PCOS. Study Design. Cross-sectional study. Setting. Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital. Subject. Two hundred and fifty Thai PCOS women who attended the Gynecologic Endocrinology Unit, during May 2007 to January 2009. Materials and Methods. The paitents were interviewed and examined for weight, height, waist circumference, and blood pressure. Venous blood samples were drawn twice, one at 12-hour fasting and the other at 2 hours after glucose loading. Results. The prevalence of glucose intolerance in Thai PCOS women was 20.0%. The mean of HOMA-IR was 3.53  ±  7.7. Area under an ROC curve for HOMA-IR for detecting glucose intolerance was 0.82. Using the cut-off value of HOMA-IR >2.0, there was sensitivity at 84.0%, specificity at 61.0%, positive predictive value at 35.0%, negative predictive value at 93.8%, and accuracy at 65.6%. Conclusion. HOMA-IR >2.0 was used for screening test for glucose intolerance in Thai PCOS women. If the result was positive, a specific test should be done to prove the diagnosis.

  19. Evaluation of organ-specific glucose metabolism by 18F-FDG in insulin receptor substrate-1 (IRS-1) knockout mice as a model of insulin resistance

    International Nuclear Information System (INIS)

    Cheng, Chao; Nakamura, Akinobu; Minamimoto, Ryogo; Shinoda, Kazuaki; Tateishi, Ukihide; Terauchi, Yasuo; Inoue, Tomio; Goto, Atsuhi; Kadowaki, Takashi

    2011-01-01

    Insulin resistance (IR) is a physiological condition in which the body produces insulin but does not result in a sufficient biological effect. Insulin resistance is usually asymptomatic but is associated with health problems and is a factor in the metabolic syndrome. The aim of the present study is to clarify organ-specific insulin resistance in normal daily conditions using [ 18 F]-2-fluoro-2-deoxy-D-glucose ([ 18 F]-FDG). The biodistribution of [ 18 F]-FDG was examined in insulin receptor substrate-1 (IRS-1) knockout mice, an animal model of skeletal muscle insulin resistance, and C57BL/6J (wild-type) mice with and without insulin loading. Mice received 0.5 MBq of [ 18 F]-FDG injected into the tail vein, immediately followed by nothing (control cohorts) or an intraperitoneal injection of 1.5 mU/g body weight of human insulin as an insulin loading test. Blood glucose concentrations for all of the experimental animals were assessed at 0, 20, 40, and 60 min post-injection. The mice were subsequently killed, and tissue was collected for evaluation of [ 18 F]-FDG biodistribution. The radioactivity of each organ was measured using a gamma counter. In the absence of insulin, the blood glucose concentrations of wild-type mice (132±26 mg/dl) and IRS-1 knockout mice (134±18 mg/dl) were not significantly different. Blood glucose concentrations decreased following insulin administration, with lower concentrations in wild-type mice than in knockout mice at 20, 40, and 60 min. A statistically significant difference in [ 18 F]-FDG uptake between wild-type mice and IRS-1 knockout mice was confirmed in the heart, abdominal muscle, and femoral muscle. With insulin loading, [ 18 F]-FDG uptake in the heart, back muscle, and abdominal muscle was significantly increased compared to without insulin loading in both wild-type mice and knockout mice. Our results showed that IR significantly affected [ 18 F]-FDG uptake in the heart in normal daily conditions. IR was associated with

  20. Importância da resitência insulínica na hepatite C crônica Insulin resistance in chronic hepatitits C

    Directory of Open Access Journals (Sweden)

    Edison Roberto Parise

    2007-06-01

    Full Text Available OBJETIVO: Revisar a importância da resistência insulínica no desenvolvimento da hepatite C crônica e sua interferência na resposta ao tratamento antiviral de pacientes infectados pelo vírus da hepatite C. FONTE DE DADOS: Revisão bibliográfica de trabalhos publicados pelo MEDLINE e dados dos próprios autores. SÍNTESE DE DADOS: Nos últimos anos, grande número de publicações tem demonstrado importante associação entre resistência insulínica e hepatite C crônica. Aumento na prevalência de diabetes mellitus tipo 2, desenvolvimento de esteatose hepática (principalmente nos pacientes com infecção pelo genótipo não-3, progressão mais rápida da doença e redução na taxa de resposta virológica sustentada ao tratamento com interferon peguilado e ribavirina, têm sido todos associados à presença de resistência insulínica nos pacientes infectados pelo vírus da hepatite C. A produção aumentada de fator de necrose tumoral pelo core do vírus da hepatite C é o principal mecanismo responsável pelo aparecimento da resistência insulínica. O fator de necrose tumoral afetaria a fosforilação do substrato do receptor de insulina diminuindo a captação de glicose e acarretando hiperinsulinemia compensatória. Aumento da siderose hepática e alterações dos níveis circulantes das adipocitocinas podem ter efeito adicional sobre a sensibilidade à insulina na hepatite C crônica. CONCLUSÕES: O diagnóstico e o tratamento da resistência insulínica nesses pacientes podem não só evitar o aparecimento das complicações, mas também prevenir a progressão da doença e, possivelmente, aumentar a taxa de resposta virológica sustentada ao tratamento com interferon peguilado e ribavirina.OBJECTIVE: To revise the importance of insulin resistance in the development of chronic hepatitis C and its interference in the response to the antiviral treatment of these patients. DATA SOURCE: Bibliographic revision of published papers in the

  1. Obese adolescent girls with polycystic ovary syndrome (PCOS) have more severe insulin resistance measured by HOMA-IR score than obese girls without PCOS.

    Science.gov (United States)

    Sawathiparnich, Pairunyar; Weerakulwattana, Linda; Santiprabhob, Jeerunda; Likitmaskul, Supawadee

    2005-11-01

    The prevalence of obesity in Thai children is increasing. These individuals are at increased risks of metabolic syndrome that includes insulin resistance, type 2 diabetes mellitus (T2DM), polycystic ovary syndrome (PCOS), dyslipidemia and hypertension. PCOS has been known to be associated with insulin resistance. To compare the insulin sensitivity between obese adolescent girls with PCOS and those without PCOS. We reviewed demographic and hormonal data of 6 obese adolescent girls with PCOS and compared with 6 age, weight and BMI-matched non-PCOS controls. Each subject underwent an oral glucose tolerance test. Homeostasis model assessment of insulin resistance score (HOMA-IR score) in obese adolescent girls with PCOS was significantly higher than in girls without PCOS with median and range as follows (16.5 [3.8, 21.8] vs. 4.1 [3.3, 6.9], p = 0.04). Our study demonstrates that obese adolescent girls with PCOS have more severe insulin resistance measured by HOMA-IR score than girls without PCOS independent of the degree of obesity. Since insulin resistance is a metabolic precursor of future cardiovascular diseases, obese adolescent girls with PCOS might be at greater risk of developing cardiovascular disease in later adulthood than their non-PCOS counterparts.

  2. Non-destructive reversible resistive switching in Cr doped Mott insulator Ca2RuO4: Interface vs bulk effects

    Science.gov (United States)

    Shen, Shida; Williamson, Morgan; Cao, Gang; Zhou, Jianshi; Goodenough, John; Tsoi, Maxim

    2017-12-01

    A non-destructive reversible resistive switching is demonstrated in single crystals of Cr-doped Mott insulator Ca2RuO4. An applied electrical bias was shown to reduce the DC resistance of the crystal by as much as 75%. The original resistance of the sample could be restored by applying an electrical bias of opposite polarity. We have studied this resistive switching as a function of the bias strength, applied magnetic field, and temperature. A combination of 2-, 3-, and 4-probe measurements provide a means to distinguish between bulk and interfacial contributions to the switching and suggests that the switching is mostly an interfacial effect. The switching was tentatively attributed to electric-field driven lattice distortions which accompany the impurity-induced Mott transition. This field effect was confirmed by temperature-dependent resistivity measurements which show that the activation energy of this material can be tuned by an applied DC electrical bias. The observed resistance switching can potentially be used for building non-volatile memory devices like resistive random access memory.

  3. Non-destructive reversible resistive switching in Cr doped Mott insulator Ca2RuO4: Interface vs bulk effects

    KAUST Repository

    Shen, Shida

    2017-12-29

    A non-destructive reversible resistive switching is demonstrated in single crystals of Cr-doped Mott insulator Ca2RuO4. An applied electrical bias was shown to reduce the DC resistance of the crystal by as much as 75%. The original resistance of the sample could be restored by applying an electrical bias of opposite polarity. We have studied this resistive switching as a function of the bias strength, applied magnetic field, and temperature. A combination of 2-, 3-, and 4-probe measurements provide a means to distinguish between bulk and interfacial contributions to the switching and suggests that the switching is mostly an interfacial effect. The switching was tentatively attributed to electric-field driven lattice distortions which accompany the impurity-induced Mott transition. This field effect was confirmed by temperature-dependent resistivity measurements which show that the activation energy of this material can be tuned by an applied DC electrical bias. The observed resistance switching can potentially be used for building non-volatile memory devices like resistive random access memory.

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

    Science.gov (United States)

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

    2018-01-01

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

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

    CERN Document Server

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

    2012-01-01

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

  6. The incidence of metabolic syndrome in obese Czech children: the importance of early detection of insulin resistance using homeostatic indexes HOMA-IR and QUICKI.

    Science.gov (United States)

    Pastucha, D; Filipčíková, R; Horáková, D; Radová, L; Marinov, Z; Malinčíková, J; Kocvrlich, M; Horák, S; Bezdičková, M; Dobiáš, M

    2013-01-01

    Common alimentary obesity frequently occurs on a polygenic basis as a typical lifestyle disorder in the developed countries. It is associated with characteristic complex metabolic changes, which are the cornerstones for future metabolic syndrome development. The aims of our study were 1) to determine the incidence of metabolic syndrome (based on the diagnostic criteria defined by the International Diabetes Federation for children and adolescents) in Czech obese children, 2) to evaluate the incidence of insulin resistance according to HOMA-IR and QUICKI homeostatic indexes in obese children with and without metabolic syndrome, and 3) to consider the diagnostic value of these indexes for the early detection of metabolic syndrome in obese children. We therefore performed anthropometric and laboratory examinations to determine the incidence of metabolic syndrome and insulin resistance in the group of 274 children with obesity (128 boys and 146 girls) aged 9-17 years. Metabolic syndrome was found in 102 subjects (37 %). On the other hand, the presence of insulin resistance according to QUICKI HOMA-IR >3.16 in 53 % of obese subjects. This HOMA-IR limit was exceeded by 70 % children in the MS(+) group, but only by 43 % children in the MS(-) group (p<0.0001). However, a relatively high incidence of insulin resistance in obese children without metabolic syndrome raises a question whether the existing diagnostic criteria do not falsely exclude some cases of metabolic syndrome. On the basis of our results we suggest to pay a preventive attention also to obese children with insulin resistance even if they do not fulfill the actual diagnostic criteria for metabolic syndrome.

  7. Trans-Fatty Acids Aggravate Obesity, Insulin Resistance and Hepatic Steatosis in C57BL/6 Mice, Possibly by Suppressing the IRS1 Dependent Pathway.

    Science.gov (United States)

    Zhao, Xiaona; Shen, Cheng; Zhu, Hong; Wang, Cong; Liu, Xiangwei; Sun, Xiaolei; Han, Shasha; Wang, Peng; Dong, Zhen; Ma, Xin; Hu, Kai; Sun, Aijun; Ge, Junbo

    2016-05-30

    Trans-fatty acid consumption has been reported as a risk factor for metabolic disorders and targeted organ damages. Nonetheless, little is known about the roles and mechanisms of trans-fatty acids in obesity, insulin resistance (IR) and hepatic steatosis. Adult C57BL/6 male mice were fed with four different diets for 20 weeks: normal diet (ND), high fat diet (HFD), low trans-fatty acids diet (LTD) and high trans-fatty acid diet (HTD). The diet-induced metabolic disorders were assessed by evaluating body weight, glucose tolerance test, hepatic steatosis and plasma lipid profiles post 20-week diet. Histological (H&E, Oil-Red-O) staining and western blot analysis were employed to assess liver steatosis and potential signaling pathways. After 20-weeks of diet, the body weights of the four groups were 29.61 ± 1.89 g (ND), 39.04 ± 4.27 g (HFD), 34.09 ± 2.62 g (LTD) and 43.78 ± 4.27 g (HTD) (p steatosis compared with HFD group possibly through regulating adipose triglyceride lipase. The group consuming the HTD also exhibited significantly reduced levels of IRS1, phosphor-PKC and phosphor-AKT. These results support our hypothesis that consumption of a diet high in trans-fatty acids induces higher rates of obesity, IR and hepatic steatosis in male C57BL/6 mice, possibly by suppressing the IRS1dependent pathway.

  8. Wushenziye Formula Improves Skeletal Muscle Insulin Resistance in Type 2 Diabetes Mellitus via PTP1B-IRS1-Akt-GLUT4 Signaling Pathway.

    Science.gov (United States)

    Tian, Chunyu; Chang, Hong; La, Xiaojin; Li, Ji-An

    2017-01-01

    Background. Wushenziye formula (WSZYF) is an effective traditional Chinese medicine in the treatment of type 2 diabetes mellitus (T2DM). Aim. This study aimed to identify the effects and underlying mechanisms of WSZYF on improving skeletal muscle insulin resistance in T2DM. Methods. An animal model of T2DM was induced by Goto-Kakizaki diabetes prone rats fed with high fat and sugar for 4 weeks. Insulin resistance model was induced in skeletal muscle cell. Results. In vivo , WSZYF improved general conditions and decreased significantly fasting blood glucose, glycosylated serum protein, glycosylated hemoglobin, insulin concentration, and insulin resistance index of T2DM rats. In vitro , WSZYF enhanced glucose consumption in insulin resistance model of skeletal muscle cell. Furthermore, WSZYF affected the expressions of molecules in regulating T2DM, including increasing the expressions of p-IRS1, p-Akt, and GLUT4, reducing PTP1B expression. Conclusion . These findings displayed the potential of WSZYF as a new drug candidate in the treatment of T2DM and the antidiabetic mechanism of WSZYF is probably mediated through modulating the PTP1B-IRS1-Akt-GLUT4 signaling pathway.

  9. Wushenziye Formula Improves Skeletal Muscle Insulin Resistance in Type 2 Diabetes Mellitus via PTP1B-IRS1-Akt-GLUT4 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Chunyu Tian

    2017-01-01

    Full Text Available Background. Wushenziye formula (WSZYF is an effective traditional Chinese medicine in the treatment of type 2 diabetes mellitus (T2DM. Aim. This study aimed to identify the effects and underlying mechanisms of WSZYF on improving skeletal muscle insulin resistance in T2DM. Methods. An animal model of T2DM was induced by Goto-Kakizaki diabetes prone rats fed with high fat and sugar for 4 weeks. Insulin resistance model was induced in skeletal muscle cell. Results. In vivo, WSZYF improved general conditions and decreased significantly fasting blood glucose, glycosylated serum protein, glycosylated hemoglobin, insulin concentration, and insulin resistance index of T2DM rats. In vitro, WSZYF enhanced glucose consumption in insulin resistance model of skeletal muscle cell. Furthermore, WSZYF affected the expressions of molecules in regulating T2DM, including increasing the expressions of p-IRS1, p-Akt, and GLUT4, reducing PTP1B expression. Conclusion. These findings displayed the potential of WSZYF as a new drug candidate in the treatment of T2DM and the antidiabetic mechanism of WSZYF is probably mediated through modulating the PTP1B-IRS1-Akt-GLUT4 signaling pathway.

  10. Índices HOMA1-IR e HOMA2-IR para identificação de resistência à insulina e síndrome metabólica: Estudo Brasileiro de Síndrome Metabólica (BRAMS)

    OpenAIRE

    Geloneze, Bruno; Vasques, Ana Carolina Junqueira; Stabe, Christiane França Camargo; Pareja, José Carlos; Rosado, Lina Enriqueta Frandsen Paez de Lima; Queiroz, Elaine Cristina de; Tambascia, Marcos Antonio

    2009-01-01

    OBJECTIVE: To investigate cut-off values for HOMA1-IR and HOMA2-IR to identify insulin resistance (IR) and metabolic syndrome (MS), and to assess the association of the indexes with components of the MS. METHODS: Nondiabetic subjects from the Brazilian Metabolic Syndrome Study were studied (n = 1,203, 18 to 78 years). The cut-off values for IR were determined from the 90th percentile in the healthy group (n = 297) and, for MS, a ROC curve was generated for the total sample. RESULTS: In the he...

  11. Thermal insulation

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  12. Electrical resistivity, heat capacity and magnetic susceptibility anomalies in Ce{sub 1-x}La{sub x}Ir{sub 2}Ge{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Mallik, R; Sampathkumaran, E V; Paulose, P L [Tata Inst. of Fundamental Research, Bombay (India)

    1997-02-01

    The results of electrical resistivity {rho} (1.4-300 K), heat capacity C and magnetic susceptibility {chi} measurements on the alloys, Ce{sub 1-x}La{sub x}Ir{sub 2}Ge{sub 2}, are reported. The results establish that CeIr{sub 2}Ge{sub 2} is one of the rare Ce compounds with a Kondo coherence temperature as large as 80 K in the trivalent limit of Ce. Apparently, {rho} exhibits non-Fermi liquid behaviour in the low-temperature {rho} data, though there is no corresponding anomaly in the C data. There is a low-temperature tail in {chi} which appears to be intrinsic. (orig.).

  13. Cellulose Insulation

    Science.gov (United States)

    1980-01-01

    Fire retardant cellulose insulation is produced by shredding old newspapers and treating them with a combination of chemicals. Insulating material is blown into walls and attics to form a fiber layer which blocks the flow of air. All-Weather Insulation's founders asked NASA/UK-TAP to help. They wanted to know what chemicals added to newspaper would produce an insulating material capable of meeting federal specifications. TAP researched the query and furnished extensive information. The information contributed to successful development of the product and helped launch a small business enterprise which is now growing rapidly.

  14. Induction of resistance to bacterial leaf blight (Xanthomonas oryzae) disease in the high yielding variety Vijaya (IR 8 x T 90)

    International Nuclear Information System (INIS)

    Padmanabhan, S.Y.; Kaur, S.; Rao, M.

    1976-01-01

    The high-yield variety Vijaya ( IR 8 x T 90), susceptible to bacterial leaf blight (Xanthomonas oryzae, Uyeda and Ishiyama Dawson), was treated with EMS to induce resistance. Dehusked seeds were pre-soaked in distilled water for 4 hrs, and subjected to 0.1% and 0.2% EMS for 6 hrs. Seed germination and survival was low in 0.2% EMS. Seedlings of M 1 were raised in pots, and panicles of individual plants harvested separately. The seeds of M 2 (8800 plants) generation were grown in nursery beds, and transplanted in field after 30 days. The plants were inoculated at the boot leaf stage with X.oryzae by the clipping method, and lesion length measured 15 days later. The frequency distribution of controls was bimodal, the EMS-treated population polymodal with new peaks. A wider range of variability was induced on the resistant and susceptible side. In M 2 0.36% resistant and 0.62% moderately resistant plants occurred. The seeds of (11) resistant and (20) moderately resistant plants of M 2 were sown for M 3 generation. These plants also segregated in the range of 0-31 and 0-32 cm lesion length. The frequency distribution curve was polymodal. M 2 from ''R'' showed 1.07% of resistant plants and 0.42% from ''MR'', against, 4.28% of moderately resistant plants from ''R'' and 3.22% from ''MR''. Susceptible plants of M 2 also segregated towards resistance (1.15%) and moderately resistant (6.96%) plants in M 3 generation. Resistant (25) and moderately resistant (147) plants of M 3 were carried forward to M 4 generation, and segregated in the range of 2.1-25 cm lesion length. The frequency curve was polymodal. No resistant plant (up to 2.0 cm lesion length) could be isolated in M 4 . The percentage of moderately resistant plants was 4.44% from ''R'' of M 3 and 4.82% from ''MR'' of M 3 and 4.77% from ''S'' of M 3 generation. The yield of resistant plants was low whereas the yield of moderately resistant plants equalled the parent; the yield of susceptible segregants equalled or

  15. Associations of Haplotypes Upstream of IRS1 with Insulin Resistance, Type 2 Diabetes, Dyslipidemia, Preclinical Atherosclerosis, and Skeletal Muscle LOC646736 mRNA Levels

    Directory of Open Access Journals (Sweden)

    Selma M. Soyal

    2015-01-01

    Full Text Available The genomic region ~500 kb upstream of IRS1 has been implicated in insulin resistance, type 2 diabetes, adverse lipid profile, and cardiovascular risk. To gain further insight into this chromosomal region, we typed four SNPs in a cross-sectional cohort and subjects with type 2 diabetes recruited from the same geographic region. From 16 possible haplotypes, 6 haplotypes with frequencies >0.01 were observed. We identified one haplotype that was protective against insulin resistance (determined by HOMA-IR and fasting plasma insulin levels, type 2 diabetes, an adverse lipid profile, increased C-reactive protein, and asymptomatic atherosclerotic disease (assessed by intima media thickness of the common carotid arteries. BMI and total adipose tissue mass as well as visceral and subcutaneous adipose tissue mass did not differ between the reference and protective haplotypes. In 92 subjects, we observed an association of the protective haplotype with higher skeletal muscle mRNA levels of LOC646736, which is located in the same haplotype block as the informative SNPs and is mainly expressed in skeletal muscle, but only at very low levels in liver or adipose tissues. These data suggest a role for LOC646736 in human insulin resistance and warrant further studies on the functional effects of this locus.

  16. Infrared-transmittance tunable metal-insulator conversion device with thin-film-transistor-type structure on a glass substrate

    Directory of Open Access Journals (Sweden)

    Takayoshi Katase

    2017-05-01

    Full Text Available Infrared (IR transmittance tunable metal-insulator conversion was demonstrated on a glass substrate by using thermochromic vanadium dioxide (VO2 as the active layer in a three-terminal thin-film-transistor-type device with water-infiltrated glass as the gate insulator. Alternative positive/negative gate-voltage applications induce the reversible protonation/deprotonation of a VO2 channel, and two-orders of magnitude modulation of sheet-resistance and 49% modulation of IR-transmittance were simultaneously demonstrated at room temperature by the metal-insulator phase conversion of VO2 in a non-volatile manner. The present device is operable by the room-temperature protonation in an all-solid-state structure, and thus it will provide a new gateway to future energy-saving technology as an advanced smart window.

  17. Insulation boards made of pentane-expanded PIR high-resistance foam; Daemmplatten aus pentan-getriebenen PIR-Hartschaeumen

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, H.U.; Calgua, E. [Elastogran GmbH, Lemfoerde (Germany)

    1999-07-01

    New pentane-expanded polyisocyanurate formulas for the continuous manufacture of dimensionally stable insulation boards with flexible covers require significantly smaller quantities of halogen-free flame proofing agents compared with polyurethane systems. At the same time they stand up to the stringent fire tests demanded by the building industry. [German] Neue, pentangetriebene Polyisocyanurat-Formulierungen fuer die kontinuierliche Herstellung von dimensionsstabilen Daemmplatten mit flexiblen Deckschichten benoetigen deutlich geringere Mengen an halogenfreien Flammschutzmitteln im Vergleich zu Polyurethan-Systemen. Trotzdem erfuellen sie die anspruchsvollen, in der Bauindustrie geforderten Brandtests. (orig.)

  18. Voltage control of metal-insulator transition and non-volatile ferroelastic switching of resistance in VOx/PMN-PT heterostructures.

    Science.gov (United States)

    Nan, Tianxiang; Liu, Ming; Ren, Wei; Ye, Zuo-Guang; Sun, Nian X

    2014-08-04

    The central challenge in realizing electronics based on strongly correlated electronic states, or 'Mottronics', lies in finding an energy efficient way to switch between the distinct collective phases with a control voltage in a reversible and reproducible manner. In this work, we demonstrate that a voltage-impulse-induced ferroelastic domain switching in the (011)-oriented 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) substrates allows a robust non-volatile tuning of the metal-insulator transition in the VOx films deposited onto them. In such a VOx/PMN-PT heterostructure, the unique two-step electric polarization switching covers up to 90% of the entire poled area and contributes to a homogeneous in-plane anisotropic biaxial strain, which, in turn, enables the lattice changes and results in the suppression of metal-insulator transition in the mechanically coupled VOx films by 6 K with a resistance change up to 40% over a broad range of temperature. These findings provide a framework for realizing in situ and non-volatile tuning of strain-sensitive order parameters in strongly correlated materials, and demonstrate great potentials in delivering reconfigurable, compactable, and energy-efficient electronic devices.

  19. Trans-Fatty Acids Aggravate Obesity, Insulin Resistance and Hepatic Steatosis in C57BL/6 Mice, Possibly by Suppressing the IRS1 Dependent Pathway

    Directory of Open Access Journals (Sweden)

    Xiaona Zhao

    2016-05-01

    Full Text Available Trans-fatty acid consumption has been reported as a risk factor for metabolic disorders and targeted organ damages. Nonetheless, little is known about the roles and mechanisms of trans-fatty acids in obesity, insulin resistance (IR and hepatic steatosis. Adult C57BL/6 male mice were fed with four different diets for 20 weeks: normal diet (ND, high fat diet (HFD, low trans-fatty acids diet (LTD and high trans-fatty acid diet (HTD. The diet-induced metabolic disorders were assessed by evaluating body weight, glucose tolerance test, hepatic steatosis and plasma lipid profiles post 20-week diet. Histological (H&E, Oil-Red-O staining and western blot analysis were employed to assess liver steatosis and potential signaling pathways. After 20-weeks of diet, the body weights of the four groups were 29.61 ± 1.89 g (ND, 39.04 ± 4.27 g (HFD, 34.09 ± 2.62 g (LTD and 43.78 ± 4.27 g (HTD (p < 0.05, respectively. HFD intake significantly impaired glucose tolerance, which was impaired further in the mice consuming the HTD diet. The effect was further exacerbated by HTD diet. Moreover, the HTD group exhibited significantly more severe liver steatosis compared with HFD group possibly through regulating adipose triglyceride lipase. The group consuming the HTD also exhibited significantly reduced levels of IRS1, phosphor-PKC and phosphor-AKT. These results support our hypothesis that consumption of a diet high in trans-fatty acids induces higher rates of obesity, IR and hepatic steatosis in male C57BL/6 mice, possibly by suppressing the IRS1dependent pathway.

  20. Distribution of resistance genetic determinants among Vibrio cholerae isolates of 2012 and 2013 outbreaks in IR Iran.

    Science.gov (United States)

    Rezaie, Niloofar; Bakhshi, Bita; Najar-Peerayeh, Shahin

    2017-03-01

    The objective of this study was to characterize antimicrobial resistance determinants in relation to antimicrobial susceptibility and genotyping profile in 20 clinical isolates of Vibrio cholerae. All of the isolates were resistant to streptomycin. The second most prevalent resistance was observed to trimethoprim (75%), co-trimoxazole (60%), tetracycline (50%), and minocycline (45%). About 50% of the isolates fulfilled the criteria of Multi Drug Resistance (MDR) phenotype. None of the isolates carried tet A, B, C, and, D determinants. This finding shows that tetracycline resistance determinants recognized so far, does not satisfactorily describe the 50% tetracycline resistance phenotype in this study, suggesting the possible contribution of other not yet characterized resistance mechanisms involved. Class 1 integron, widely distributed among enteric bacteria, was not detected among V. cholerae strains under study. Conversely, 100% of the isolates harbored SXT constin (int) , among which 70% were positive for dfrA1, strA, and strB genes. The sul1gene was present in 60% of the isolates while none of them contained floR gene. All the isolates uniformly appeared to be identical in fingerprinting profiles expected from outbreak strains. In conclusion, SXT element with its mosaic structure was the exclusive antimicrobial resistance determinant of clonal V. cholerae isolates taken from outbreaks of 2012 and 2013 in Iran. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Polyethylene Nanocomposites for the Next Generation of Ultralow-Transmission-Loss HVDC Cables: Insulation Containing Moisture-Resistant MgO Nanoparticles.

    Science.gov (United States)

    Pourrahimi, Amir Masoud; Pallon, Love K H; Liu, Dongming; Hoang, Tuan Anh; Gubanski, Stanislaw; Hedenqvist, Mikael S; Olsson, Richard T; Gedde, Ulf W

    2016-06-15

    The use of MgO nanoparticles in polyethylene for cable insulation has attracted considerable interest, although in humid media the surface regions of the nanoparticles undergo a conversion to a hydroxide phase. A facile method to obtain MgO nanoparticles with a large surface area and remarkable inertness to humidity is presented. The method involves (a) low temperature (400 °C) thermal decomposition of Mg(OH)2, (b) a silicone oxide coating to conceal the nanoparticles and prevent interparticle sintering upon exposure to high temperatures, and (c) heat treatment at 1000 °C. The formation of the hydroxide phase on these silicone oxide-coated MgO nanoparticles after extended exposure to humid air was assessed by thermogravimetry, infrared spectroscopy, and X-ray diffraction. The nanoparticles showed essentially no sign of any hydroxide phase compared to particles prepared by the conventional single-step thermal decomposition of Mg(OH)2. The moisture-resistant MgO nanoparticles showed improved dispersion and interfacial adhesion in the LDPE matrix with smaller nanosized particle clusters compared with conventionally prepared MgO. The addition of 1 wt % moisture-resistant MgO nanoparticles was sufficient to decrease the conductivity of polyethylene 30 times. The reduction in conductivity is discussed in terms of defect concentration on the surface of the moisture-resistant MgO nanoparticles at the polymer/nanoparticle interface.

  2. Estimating Rate of Insulin Resistance in Patients with Preeclampsia Using HOMA-IR Index and Comparison with Nonpreeclampsia Pregnant Women

    OpenAIRE

    Abhari, Farideh Rezaei; Ghanbari Andarieh, Maryam; Farokhfar, Asadollah; Ahmady, Soleiman

    2014-01-01

    Women with preeclampsia, independent of obesity and glucose intolerance, exhibit insulin resistance during pregnancy. The purpose of the present study is to determine whether early diagnosis of insulin resistance during pregnancy can predict preeclampsia. Through a case-control study, 675 pregnant women were selected and their first trimester blood was taken. Their fasting blood glucose and insulin were also measured after diagnosis of preeclampsia by 20 weeks of pregnancy. Based on the exper...

  3. Insulators for fusion applications

    International Nuclear Information System (INIS)

    1987-04-01

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

  4. Study on radiation resistance of electro insulating materials used in high-voltage equipment at Chernobylsk NPP; Issledovanie radiatsionnoj stojkosti ehlektroizolyatsionnykh materialov, primenyaemykh v vytsfsokovol`tnom oborudovanii na Chernobyl`skoj AEhS

    Energy Technology Data Exchange (ETDEWEB)

    Lizunov, S D [and others

    1994-12-31

    Investigations into the radiation resistance of the transformer oil and electro insulating cardboard during emergency irradiation at the NPP in 1986 are conducted. It is shown that as a result of transformer oil irradiation it is decomposed with the release of hydrogen, ethane, ethylene, ethane and other gases.

  5. Third Exposure to a Reduced Carbohydrate Meal Lowers Evening Postprandial Insulin and GIP Responses and HOMA-IR Estimate of Insulin Resistance.

    Science.gov (United States)

    Lin, Po-Ju; Borer, Katarina T

    2016-01-01

    Postprandial hyperinsulinemia, hyperglycemia, and insulin resistance increase the risk of type 2 diabetes (T2D) and cardiovascular disease mortality. Postprandial hyperinsulinemia and hyperglycemia also occur in metabolically healthy subjects consuming high-carbohydrate diets particularly after evening meals and when carbohydrate loads follow acute exercise. We hypothesized the involvement of dietary carbohydrate load, especially when timed after exercise, and mediation by the glucose-dependent insulinotropic peptide (GIP) in this phenomenon, as this incretin promotes insulin secretion after carbohydrate intake in insulin-sensitive, but not in insulin-resistant states. Four groups of eight metabolically healthy weight-matched postmenopausal women were provided with three isocaloric meals (a pre-trial meal and two meals during the trial day) containing either 30% or 60% carbohydrate, with and without two-hours of moderate-intensity exercise before the last two meals. Plasma glucose, insulin, glucagon, GIP, glucagon-like peptide 1 (GLP-1), free fatty acids (FFAs), and D-3-hydroxybutyrate concentrations were measured during 4-h postprandial periods and 3-h exercise periods, and their areas under the curve (AUCs) were analyzed by mixed-model ANOVA, and insulin resistance during fasting and meal tolerance tests within each diet was estimated using homeostasis-model assessment (HOMA-IR). The third low-carbohydrate meal, but not the high-carbohydrate meal, reduced: (1) evening insulin AUC by 39% without exercise and by 31% after exercise; (2) GIP AUC by 48% without exercise and by 45% after exercise, and (3) evening insulin resistance by 37% without exercise and by 24% after exercise. Pre-meal exercise did not alter insulin-, GIP- and HOMA-IR- lowering effects of low-carbohydrate diet, but exacerbated evening hyperglycemia. Evening postprandial insulin and GIP responses and insulin resistance declined by over 30% after three meals that limited daily carbohydrate intake to

  6. Resistência insulínica e sua relação com os componentes da síndrome metabólica

    Directory of Open Access Journals (Sweden)

    Carla Campos Muniz Medeiros

    2011-11-01

    Full Text Available FUNDAMENTO: Os portadores de resistência à insulina apresentam maior predisposição para desenvolver posteriormente Síndrome Metabólica (SM, Diabetes Mellitus tipo 2 e Doença Cardiovascular (DCV. OBJETIVO: Avaliar a associação entre resistência insulínica (RI e os componentes da síndrome metabólica. MÉTODOS: Estudo transversal envolvendo 196 indivíduos entre 2 e 18 anos, usuários do sistema único de saúde. A associação da RI com os componentes da SM foi avaliada pelo teste do qui-quadrado, adotando-se o valor do índice da homeostase glicêmica (HOMA-RI > 2,5, e pelo teste de variância (ANOVA e Tukey, por meio da comparação das médias dos componentes nos quartis do HOMA-RI. A análise estatística foi realizada através do SPSS 17.0, com a adoção do nível de significância de 5%. RESULTADOS: RI foi observada em 41,3% da população estudada e esteve associada à faixa etária entre 10-18 anos (p = 0,002 RP = 3,2, à SM em ambos os sexos [Masculino (p = 0,022 RP = 3,7 e Feminino (p = 0,007 RP = 2,7] e ao triglicerídeo alterado (p = 0,005 RP = 2,9 no sexo feminino. Os valores médios dos componentes da SM diferiram significativamente entre os quartis do HOMA-RI (p < 0,01, com exceção do HDL-colesterol. CONCLUSÃO: A resistência insulínica pode ser considerada um marcador de risco cardiovascular.

  7. Optimal cut-off values for the homeostasis model assessment of insulin resistance (HOMA-IR) and pre-diabetes screening: Developments in research and prospects for the future.

    Science.gov (United States)

    Tang, Qi; Li, Xueqin; Song, Peipei; Xu, Lingzhong

    2015-12-01

    Diabetes mellitus (DM) appears to be increasing rapidly, threatening to reduce life expectancy for humans around the globe. The International Diabetes Federation (IDF) has estimated that there will be 642 million people living with the disease by 2040 and half as many again who will be not diagnosed. This means that pre-DM screening is a critical issue. Insulin resistance (IR) has emerged as a major pathophysiological factor in the development and progression of DM since it is evident in susceptible individuals at the early stages of DM, and particularly type 2 DM (T2DM). Therefore, assessment of IR via the homeostasis model assessment of IR (HOMA-IR) is a key index for the primary prevention of DM and is thus found in guidelines for screening of high-risk groups. However, the cut-off values of HOMA-IR differ for different races, ages, genders, diseases, complications, etc. due to the complexity of IR. This hampers the determination of specific cut-off values of HOMA-IR in different places and in different situations. China has not published an official index to gauge IR for primary prevention of T2DM in the diabetic and non-diabetic population except for children and adolescents ages 6-12 years. Hence, this article summarizes developments in research on IR, HOMA-IR, and pre-DM screening in order to provide a reference for optimal cut-off values of HOMA-IR for the diagnosis of DM in the Chinese population.

  8. Screening of IR50 x Rathu Heenati F7 RILs and identification of SSR markers linked to brown planthopper (Nilaparvata lugens Stål) resistance in rice (Oryza sativa L.).

    Science.gov (United States)

    Kumari, Sanju; M Sheba, Jennifer; Marappan, Maheshwaran; Ponnuswamy, Shanmugasunderam; Seetharaman, Suresh; Pothi, Nagarajan; Subbarayalu, Mohankumar; Muthurajan, Raveendran; Natesan, Senthil

    2010-09-01

    Brown planthopper (Nilaparvata lugens Stål) is one of the major insect pests of rice. A Sri Lankan indica rice cultivar Rathu Heenati was found to be resistant to all biotypes of the brown planthopper. In the present study, a total of 268 F(7) RILs of IR50 and Rathu Heenati were phenotyped for their level of resistance against BPH by the standard seedbox screening test (SSST) in the greenhouse. A total of 53 SSR primers mapped on the chromosome 3 were used to screen the polymorphism between the parents IR50 and Rathu Heenati, out of which eleven were found to be polymorphic between IR50 and Rathu Heenati. The eleven primers that have shown polymorphism between the IR50 and Rathu Heenati parents were genotyped in a set of five resistant RILs and five susceptible RILs along with the parents for co-segregation analysis. Among the eleven primers, two primers namely RM3180 (18.22 Mb) and RM2453 (20.19 Mb) showed complete co-segregation with resistance. The identification of SSR markers linked with BPH resistant could be used for the maker assisted selection (MAS) program in rice breeding and to map the resistant genes on rice chromosomes for further gene cloning.

  9. [Effect of metabolic uncontrolled diabetes mellitus (DM) on the resistance index of renal (IR) Interlobar arteries assessed with pulsed Doppler].

    Science.gov (United States)

    Muraira-Cárdenas, Luis Cesar; Barrios-Pérez, Martín

    2016-01-01

    Diabetes mellitus is a chronic degenerative disease characterized by elevated hyperglycemia, triggering a series of processes and culminating in chronic, uncontrolled, cellular and vascular damage in different organs. To assess whether the elevated glycosylated hemoglobin, microalbuminuria, and the time evolution of more than 10 years of diabetes mellitus are associated with elevated resistance index of the interlobar renal arteries assessed with pulsed Doppler in patients with metabolic uncontrolled diabetes mellitus. Transversal-analytical, observational, prospective study that included diabetic patients attending UMAE abdominal ultrasound in 25 of IMSS, from October 15, 2014 to November 15, 2014, which was performed for pulsed Doppler index resistance of vascular interlobar renal arteries and was collected from electronic medical records: age, sex, glycated hemoglobin, and microalbuminuria. The association between metabolic uncontrolled diabetes mellitus was analyzed with the elevation of resistance index by χ(2) test or Fisher, being significant with a value of p diabetes were examined, with an average age of 52.3 ± 14.2 years, 41 were older than 50 years (65.0%), 26 with hypertension (41.2%), 32 with higher levels of glycated hemoglobin 7 (50.8%), 35 with normoalbuminuria (55.6%), 28 with microalbuminuria (44.4%), and 39 with a time evolution of diabetes of more than 10 years (61.9%). We observed a statistically significant difference between microalbuminuria and increased duration of diabetes mellitus with high resistance index. The alterations in renal microvasculature conditioned by the occurrence of microalbuminuria in diabetic nephropathy and the duration of diabetes are strongly associated with higher resistance index.

  10. Green insulation: hemp fibers

    Energy Technology Data Exchange (ETDEWEB)

    Anon,

    2011-09-15

    Indian hemp (Cannabis indica) is known for its psychotropic values and it is banned in most countries. However, industrial hemp (Cannabis sativa) is known for its tough fibers. Several manufactures in Europe including, small niche players, have been marketing hemp insulation products for several years. Hemp is a low environmental impact material. Neither herbicide nor pesticide is used during the growth of hemp. The fibers are extracted in a waste-free and chemical-free mechanical process. Hemp can consume CO2 during its growth. In addition, hemp fiber can be disposed of harmlessly by composting or incineration at the end of its life. Hemp fibers are processed and treated only minimally to resist rot and fungal activity. There is little health risk when producing and installing the insulation, thanks to the absence of toxic additive. Its thermal resistance is comparable to mineral wool. But the development and marketing of hemp fibers may be restricted in North America.

  11. Thermal insulation

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  12. Topological insulators

    CERN Document Server

    Franz, Marcel

    2013-01-01

    Topological Insulators, volume six in the Contemporary Concepts of Condensed Matter Series, describes the recent revolution in condensed matter physics that occurred in our understanding of crystalline solids. The book chronicles the work done worldwide that led to these discoveries and provides the reader with a comprehensive overview of the field. Starting in 2004, theorists began to explore the effect of topology on the physics of band insulators, a field previously considered well understood. However, the inclusion of topology brings key new elements into this old field. Whereas it was

  13. Evaluation of Mid-IR Laser radiation effect on 316l stainless steel corrosion resistance in physiological saline

    International Nuclear Information System (INIS)

    Khosroshahi, M.E.; Valanezhad, A.; Tavakoli, J.

    2004-01-01

    The effects of a short pulsed (∼ 400 ns ) multi line hydrogen fluoride laser radiation operating on average at 2.8 μm has been studied on 316l stainless steel in terms of optical and physical parameters. At low fluences ≤ 8 Jcm -2 (phase l) no morphological changes occurred at the surface and melting began at ∼ 8.8 Jcm -2 (phase l l) which continued up to about 30 Jcm -2 . In this range the melting zone was effectively produced by high temperature surface centres growth which subsequently joined these centres together. Thermal ablation via surface vaporization began at ∼ 33 Jcm -2 (phase lll). The results of scanning electron microscopy evaluation and corrosion resistance experiment which was carried out using Eg and G device with cyclic potentiodynamic polarization method in a physiological (Hank's) solution indicated that pitting corrosion sensitivity was decreased i.e.. enhancement of corrosion resistance. Also, the x-ray diffraction results showed a double increase of γ (lll) at microstructure, thus in effect a super austenite stainless steel was obtained at an optimized melting fluence

  14. Insulation Reformulation Development

    Science.gov (United States)

    Chapman, Cynthia; Bray, Mark

    2015-01-01

    The current Space Launch System (SLS) internal solid rocket motor insulation, polybenzimidazole acrylonitrile butadiene rubber (PBI-NBR), is a new insulation that replaced asbestos-based insulations found in Space Shuttle heritage solid rocket boosters. PBI-NBR has some outstanding characteristics such as an excellent thermal erosion resistance, low thermal conductivity, and low density. PBI-NBR also has some significant challenges associated with its use: Air entrainment/entrapment during manufacture and lay-up/cure and low mechanical properties such as tensile strength, modulus, and fracture toughness. This technology development attempted to overcome these challenges by testing various reformulated versions of booster insulation. The results suggest the SLS program should continue to investigate material alternatives for potential block upgrades or use an entirely new, more advanced booster. The experimental design was composed of a logic path that performs iterative formulation and testing in order to maximize the effort. A lab mixing baseline was developed and documented for the Rubber Laboratory in Bldg. 4602/Room 1178.

  15. The effect of aerobic training on CXL5, tumor necrosis factor α and insulin resistance index (HOMA-IR) in sedentary obese women.

    Science.gov (United States)

    Zehsaz, Farzad; Farhangi, Negin; Mirheidari, Lamia

    2014-01-01

    The purpose of the present study was to investigate the effects of a 12-week training program on serum CXC ligand 5, tumor necrosis factor α (TNF-α) and insulin resistance index in obese sedentary women. To this end, twenty-four obese sedentary women were evaluated before and after a 12-week exercise program including a brief warm-up, followed by ~45 min per session of aerobic exercise at an intensity of 60-75% of age-predicted maximum heart rate (~300 kcal/day), followed by a brief cool down, five times per week. After the exercise program, body weight, waist circumference, waist to hip ratio, percentage body fat mass, fasting glucose and insulin of participants were decreased. Furthermore, serum CXCL5 levels were significantly decreased from 2693.2 ±375.8 to 2290.2 ±345.9 pg/ml (p HOMA-IR (p < 0.001) and TNF-α (p < 0.001). Exercise training induced weight loss resulted in a significant reduction in serum CXCL5 concentrations and caused an improvement in insulin resistance in obese sedentary women.

  16. Scalable cross-point resistive switching memory and mechanism through an understanding of H2O2/glucose sensing using an IrOx/Al2O3/W structure.

    Science.gov (United States)

    Chakrabarti, Somsubhra; Maikap, Siddheswar; Samanta, Subhranu; Jana, Surajit; Roy, Anisha; Qiu, Jian-Tai

    2017-10-04

    The resistive switching characteristics of a scalable IrO x /Al 2 O 3 /W cross-point structure and its mechanism for pH/H 2 O 2 sensing along with glucose detection have been investigated for the first time. Porous IrO x and Ir 3+ /Ir 4+ oxidation states are observed via high-resolution transmission electron microscope, field-emission scanning electron spectroscopy, and X-ray photo-electron spectroscopy. The 20 nm-thick IrO x devices in sidewall contact show consecutive long dc cycles at a low current compliance (CC) of 10 μA, multi-level operation with CC varying from 10 μA to 100 μA, and long program/erase endurance of >10 9 cycles with 100 ns pulse width. IrO x with a thickness of 2 nm in the IrO x /Al 2 O 3 /SiO 2 /p-Si structure has shown super-Nernstian pH sensitivity of 115 mV per pH, and detection of H 2 O 2 over the range of 1-100 nM is also achieved owing to the porous and reduction-oxidation (redox) characteristics of the IrO x membrane, whereas a pure Al 2 O 3 /SiO 2 membrane does not show H 2 O 2 sensing. A simulation based on Schottky, hopping, and Fowler-Nordheim tunneling conduction, and a redox reaction, is proposed. The experimental I-V curve matches very well with simulation. The resistive switching mechanism is owing to O 2- ion migration, and the redox reaction of Ir 3+ /Ir 4+ at the IrO x /Al 2 O 3 interface through H 2 O 2 sensing as well as Schottky barrier height modulation is responsible. Glucose at a low concentration of 10 pM is detected using a completely new process in the IrO x /Al 2 O 3 /W cross-point structure. Therefore, this cross-point memory shows a method for low cost, scalable, memory with low current, multi-level operation, which will be useful for future highly dense three-dimensional (3D) memory and as a bio-sensor for the future diagnosis of human diseases.

  17. Chromium–niobium co-doped vanadium dioxide films: Large temperature coefficient of resistance and practically no thermal hysteresis of the metal–insulator transition

    Directory of Open Access Journals (Sweden)

    Kenichi Miyazaki

    2016-05-01

    Full Text Available We investigated the effects of chromium (Cr and niobium (Nb co-doping on the temperature coefficient of resistance (TCR and the thermal hysteresis of the metal–insulator transition of vanadium dioxide (VO2 films. We determined the TCR and thermal-hysteresis-width diagram of the V1−x−yCrxNbyO2 films by electrical-transport measurements and we found that the doping conditions x ≳ y and x + y ≥ 0.1 are appropriate for simultaneously realizing a large TCR value and an absence of thermal hysteresis in the films. By using these findings, we developed a V0.90Cr0.06Nb0.04O2 film grown on a TiO2-buffered SiO2/Si substrate that showed practically no thermal hysteresis while retaining a large TCR of 11.9%/K. This study has potential applications in the development of VO2-based uncooled bolometers.

  18. Status of surface conduction in topological insulators

    International Nuclear Information System (INIS)

    Barua, Sourabh; Rajeev, K. P.

    2014-01-01

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

  19. Study of the degradation of the insulation of HV cables with PVC insulation

    International Nuclear Information System (INIS)

    Quennehen, Pierre

    2014-01-01

    The observed decrease in the resistivity of the PVC insulation of some high voltage unipolar cables led to question their ability to perform their function. Provide answers concerning in particular the origin of the variation in resistivity and the impact on the dielectric strength were the objectives of this study. The characterizations were carried on cables withdrawn from service whose properties had changed during their use. Physico-chemical characterization (IR microscopy, UV spectroscopy, SEM - EDX and coulometry) showed that aging of the cable resulted from a mechanism of dehydro-chlorination. The presence of two modes of electric conduction in the material was observed: electronic conduction at a low temperature (≤ -10 C) and ionic conduction at room temperature and beyond. The presence of these two modes of conduction is consistent with the mechanism of dehydro-chlorination. In contrast to an Arrhenius law, artificial aging showed a threshold effect in the thermal activation of the mechanism at the origin of the resistivity drop. The dielectric strength of the cable has been confirmed by tests at voltages or temperatures well beyond the nominal values. Measurements of differential scanning calorimetry (DSC) showed occasional more or less pronounced over-heatings that correlate with the resistivity drops, and can therefore be considered as being at the origin of the observed evolutions. (author)

  20. Insulated pipe clamp design

    International Nuclear Information System (INIS)

    Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

    1980-01-01

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. The design considerations and methods along with the development tests are presented. Special considerations to guard against adverse cracking of the insulation material, to maintain the clamp-pipe stiffness desired during a seismic event, to minimize clamp restraint on the pipe during normal pipe heatup, and to resist clamp rotation or spinning on the pipe are emphasized

  1. Polyester Apparel Cutting Waste as Insulation Material

    OpenAIRE

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

    2017-01-01

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

  2. Increase in homeostasis model assessment of insulin resistance (HOMA-IR) had a strong impact on the development of type 2 diabetes in Japanese individuals with impaired insulin secretion: the Saku study.

    Science.gov (United States)

    Morimoto, Akiko; Tatsumi, Yukako; Soyano, Fumie; Miyamatsu, Naomi; Sonoda, Nao; Godai, Kayo; Ohno, Yuko; Noda, Mitsuhiko; Deura, Kijyo

    2014-01-01

    Our aim was to assess the impact of increase in homeostasis model assessment of insulin resistance (HOMA-IR) on the development of type 2 diabetes in Japanese individuals with impaired insulin secretion (IIS). This study included 2,209 participants aged 30-69 without diabetes at baseline who underwent comprehensive medical check-ups between April 2006 and March 2007 at Saku Central Hospital. Participants were classified into eight groups according to the combination of baseline IIS status (non-IIS and IIS) and category of HOMA-IR change between the baseline and follow-up examinations (decrease, no change/small increase, moderate increase, and large increase). Type 2 diabetes was determined from fasting and 2 h post-load plasma glucose concentrations at the follow-up examination between April 2009 and March 2011. At baseline, 669 individuals (30.3%) were classified as having IIS. At follow-up, 74 individuals developed type 2 diabetes. After adjusting for confounding factors including baseline HOMA-IR values, the multivariable-adjusted odds ratios (95% confidence intervals) for type 2 diabetes in the non-IIS with a decrease (mean change in HOMA-IR: -0.47), non-IIS with a moderate increase (mean change in HOMA-IR: 0.28), non-IIS with a large increase (mean change in HOMA-IR: 0.83), IIS with a decrease (mean change in HOMA-IR: -0.36), IIS with no change/small increase (mean change in HOMA-IR: 0.08), IIS with a moderate increase (mean change in HOMA-IR: 0.27), and IIS with a large increase (mean change in HOMA-IR: 0.73) groups, relative to the non-IIS with no change/small increase (mean change in HOMA-IR: 0.08) group were 0.23 (0.04, 1.11), 1.22 (0.26, 5.72), 2.01 (0.70, 6.46), 1.37 (0.32, 4.28), 3.60 (0.83, 15.57), 5.24 (1.34, 20.52), and 7.01 (1.75, 24.18), respectively. Moderate and large increases in HOMA-IR had a strong impact on the development of type 2 diabetes among individuals with IIS in this Japanese population.

  3. Impaired Insulin Signaling is Associated with Hepatic Mitochondrial Dysfunction in IR+/−-IRS-1+/− Double Heterozygous (IR-IRS1dh Mice

    Directory of Open Access Journals (Sweden)

    Andras Franko

    2017-05-01

    Full Text Available Mitochondria play a pivotal role in energy metabolism, but whether insulin signaling per se could regulate mitochondrial function has not been identified yet. To investigate whether mitochondrial function is regulated by insulin signaling, we analyzed muscle and liver of insulin receptor (IR+/−-insulin receptor substrate-1 (IRS-1+/− double heterozygous (IR-IRS1dh mice, a well described model for insulin resistance. IR-IRS1dh mice were studied at the age of 6 and 12 months and glucose metabolism was determined by glucose and insulin tolerance tests. Mitochondrial enzyme activities, oxygen consumption, and membrane potential were assessed using spectrophotometric, respirometric, and proton motive force analysis, respectively. IR-IRS1dh mice showed elevated serum insulin levels. Hepatic mitochondrial oxygen consumption was reduced in IR-IRS1dh animals at 12 months of age. Furthermore, 6-month-old IR-IRS1dh mice demonstrated enhanced mitochondrial respiration in skeletal muscle, but a tendency of impaired glucose tolerance. On the other hand, 12-month-old IR-IRS1dh mice showed improved glucose tolerance, but normal muscle mitochondrial function. Our data revealed that deficiency in IR/IRS-1 resulted in normal or even elevated skeletal muscle, but impaired hepatic mitochondrial function, suggesting a direct cross-talk between insulin signaling and mitochondria in the liver.

  4. Correlation between Interleukin-6 (IL-6, High Sensitivity C-Reactive Protein (hsCRP, Endothelin-1 (ET-1, Asymmetric Dimethylarginine (ADMA and Insulin Resistance (HOMA-IR in Central Obese Men

    Directory of Open Access Journals (Sweden)

    Andri Hidayat

    2011-04-01

    Full Text Available BACKGROUND: Many studies have shown that obesity was closely related to insulin resistance via several pathways such as inflammation, oxidative stress, lipolysis, and endothelial dysfunction. This study was carried out to observe the correlation between inflammation (IL-6 and hsCRP, lipolysis process (ET-1, and endothelial dysfunction (ADMA and insulin resistance (HOMA-IR in centrally obese men. METHODS: This was a cross sectional study on 62 male subjects aged 30–60 years old with waist circumference (WC >90 cm. IL-6, ET-1 and ADMA levels were measured using ELISA method, while hsCRP and insulin were measured using chemiluminescence method. All blood testings were conducted in Prodia Clinical Laboratory. RESULTS: The results showed that WC was significantly correlated with hsCRP (r=0.294, p=0.022, ET-1 (r=0.257, p=0.047 and ADMA (r=0.338, p=0.009. We also found a significant correlation between hsCRP with HOMA-IR (r=0.324, p=0.021, ADMA with HOMA-IR (r=0.280, p=0.045 and IL-6 with hsCRP (r=0.437, p=0.003. CONCLUSIONS: hsCRP and ADMA have significant correlation with HOMA-IR in centrally obese men. HOMA-IR significantly increases in subjects with ADMA above median and either IL-6 or hsCRP above median, as compared to those in the other groups. Inflammation and endothelial dysfunction are important causal pathways of insulin resistance state in centrally obese men. KEYWORDS: obesity, IL-6, hsCRP, ET-1, ADMA, HOMA-IR.

  5. A novel PTP1B inhibitor extracted from Ganoderma lucidum ameliorates insulin resistance by regulating IRS1-GLUT4 cascades in the insulin signaling pathway.

    Science.gov (United States)

    Yang, Zhou; Wu, Fan; He, Yanming; Zhang, Qiang; Zhang, Yuan; Zhou, Guangrong; Yang, Hongjie; Zhou, Ping

    2018-01-24

    Insulin resistance caused by the overexpression of protein tyrosine phosphatase 1 B (PTP1B) as well as the dephosphorylation of its target is one of the main causes of type 2 diabetes (T2D). A newly discovered proteoglycan, Fudan-Yueyang Ganoderma lucidum (FYGL) extracted from Ganoderma lucidum, was first reported to be capable of competitively inhibiting PTP1B activity in vitro in our previous work. In the present study, we sought to reveal the mechanism of PTP1B inhibition by FYGL at the animal and cellular levels. We found that FYGL can decrease blood glucose, reduce body weight and ameliorate insulin resistance in ob/ob mice. Decrease of PTP1B expression and increase of the phosphorylation of PTP1B targets in the insulin signaling pathway of skeletal muscles were observed. In order to clearly reveal the underlying mechanism of the hypoglycemic effect caused by FYGL, we further investigated the effects of FYGL on the PTP1B-involved insulin signaling pathway in rat myoblast L6 cells. We demonstrated that FYGL had excellent cell permeability by using a confocal laser scanning microscope and a flow cytometer. We found that FYGL had a positive effect on insulin-stimulated glucose uptake by using the 2-deoxyglucose (2-DG) method. FYGL could inhibit PTP1B expression at the mRNA level, phosphorylating insulin receptor substrate-1 (IRS1), as well as activating phosphatidylinositol-3 kinase (PI3K) and protein kinase B (Akt). Finally, FYGL increased the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) and consequently up-regulated the expression of glucose transporter type 4 (GLUT4), promoting GLUT4 transportation to the plasma membrane in PTP1B-transfected L6 cells. Our study provides theoretical evidence for FYGL to be potentially used in T2D management.

  6. Tank Insulation

    Science.gov (United States)

    1979-01-01

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

  7. Metal-insulator transitions

    Science.gov (United States)

    Imada, Masatoshi; Fujimori, Atsushi; Tokura, Yoshinori

    1998-10-01

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

  8. Gamma glutamyl transferase is an independent determinant for the association of insulin resistance with nonalcoholic fatty liver disease in Bangladeshi adults: Association of GGT and HOMA-IR with NAFLD.

    Science.gov (United States)

    Hossain, Israt Ara; Rahman Shah, Md Mijanur; Rahman, Mohammad Khalilur; Ali, Liaquat

    2016-01-01

    Nonalcoholic fatty liver disease (NAFLD) is a major cause of liver-related morbidity and is frequently associated with insulin resistance (HOMA-IR) syndrome. Recently serum gamma glutamyl transferase (GGT) has been considered as surrogate marker of NAFLD leading to oxidative stress and hepatocellular damage. In the present study we examined the association of serum GGT and HOMA-IR with NAFLD in Bangladeshi adult subjects. Under a cross-sectional analytical design a total of 110 subjects were recruited who came for their routine health check up in the BIHS Hospital, Darussalam, Dhaka, Bangladesh. After whole abdomen ultrasonography, 62 were diagnosed as non-NAFLD and 48 were NAFLD subjects. Serum glucose was measured by glucose-oxidase method, lipid profile and liver enzymes by enzymatic colorimetric method, glycosylated hemoglobin (HbA1c) was measured by high performance liquid chromatography (HPLC), serum insulin were measured by enzyme-linked immunosorbent assay. HOMA-IR was calculated by homeostasis model assessment (HOMA). NAFLD subjects had significantly higher levels of GGT and HOMA-IR as compared to their non-NAFLD counterparts. Multiple linear regression analysis showed a significant positive association of HOMA-IR with GGT after adjusting the effects of waist circumference (WC) and HbA1c. In binary logistic regression analysis, HOMA-IR and GGT were found to be significant determinants of NAFLD after adjusting the effects of WC and HbA1c. These results suggest that elevated levels of GGT and insulin resistance are more likely to develop NAFLD and thus support a role of these determinants in the pathogenesis of NAFLD in Bangladeshi adult subjects. Copyright © 2015 Diabetes India. Published by Elsevier Ltd. All rights reserved.

  9. Insulin resistance index (HOMA-IR) levels in a general adult population: curves percentile by gender and age. The EPIRCE study.

    Science.gov (United States)

    Gayoso-Diz, Pilar; Otero-Gonzalez, Alfonso; Rodriguez-Alvarez, María Xosé; Gude, Francisco; Cadarso-Suarez, Carmen; García, Fernando; De Francisco, Angel

    2011-10-01

    To describe the distribution of HOMA-IR levels in a general nondiabetic population and its relationships with metabolic and lifestyles characteristics. Cross-sectional study. Data from 2246 nondiabetic adults in a random Spanish population sample, stratified by age and gender, were analyzed. Assessments included a structured interview, physical examination, and blood sampling. Generalized additive models (GAMs) were used to assess the effect of lifestyle habits and clinical and demographic measurements on HOMA-IR. Multivariate GAMs and quantile regression analyses of HOMA-IR were carried out separately in men and women. This study shows refined estimations of HOMA-IR levels by age, body mass index, and waist circumference in men and women. HOMA-IR levels were higher in men (2.06) than women (1.95) (P=0.047). In women, but not men, HOMA-IR and age showed a significant nonlinear association (P=0.006), with increased levels above fifty years of age. We estimated HOMA-IR curves percentile in men and women. Age- and gender-adjusted HOMA-IR levels are reported in a representative Spanish adult non-diabetic population. There are gender-specific differences, with increased levels in women over fifty years of age that may be related with changes in body fat distribution after menopause. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Anisotropic Magnetoresistance in Antiferromagnetic Sr_{2}IrO_{4}

    Directory of Open Access Journals (Sweden)

    C. Wang

    2014-11-01

    Full Text Available We report point-contact measurements of anisotropic magnetoresistance (AMR in a single crystal of antiferromagnetic Mott insulator Sr_{2}IrO_{4}. The point-contact technique is used here as a local probe of magnetotransport properties on the nanoscale. The measurements at liquid nitrogen temperature reveal negative magnetoresistances (up to 28% for modest magnetic fields (250 mT applied within the IrO_{2} a-b plane and electric currents flowing perpendicular to the plane. The angular dependence of magnetoresistance shows a crossover from fourfold to twofold symmetry in response to an increasing magnetic field with angular variations in resistance from 1% to 14%. We tentatively attribute the fourfold symmetry to the crystalline component of AMR and the field-induced transition to the effects of applied field on the canting of antiferromagnetic-coupled moments in Sr_{2}IrO_{4}. The observed AMR is very large compared to the crystalline AMRs in 3d transition metal alloys or oxides (0.1%–0.5% and can be associated with the large spin-orbit interactions in this 5d oxide while the transition provides evidence of correlations between electronic transport, magnetic order, and orbital states. The finding of this work opens an entirely new avenue to not only gain a new insight into physics associated with spin-orbit coupling but also to better harness the power of spintronics in a more technically favorable fashion.

  11. Electrical Control of Structural and Physical Properties via Strong Spin-Orbit Interactions in Sr2IrO4

    Science.gov (United States)

    Cao, G.; Terzic, J.; Zhao, H. D.; Zheng, H.; De Long, L. E.; Riseborough, Peter S.

    2018-01-01

    Electrical control of structural and physical properties is a long-sought, but elusive goal of contemporary science and technology. We demonstrate that a combination of strong spin-orbit interactions (SOI) and a canted antiferromagnetic Mott state is sufficient to attain that goal. The antiferromagnetic insulator Sr2IrO4 provides a model system in which strong SOI lock canted Ir magnetic moments to IrO6 octahedra, causing them to rigidly rotate together. A novel coupling between an applied electrical current and the canting angle reduces the Néel temperature and drives a large, nonlinear lattice expansion that closely tracks the magnetization, increases the electron mobility, and precipitates a unique resistive switching effect. Our observations open new avenues for understanding fundamental physics driven by strong SOI in condensed matter, and provide a new paradigm for functional materials and devices.

  12. Metal-insulator transition upon heating and negative-differential-resistive-switching induced by self-heating in BaCo{sub 0.9}Ni{sub 0.1}S{sub 1.8}

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, B.; Genossar, J.; Chashka, K. B.; Patlagan, L.; Reisner, G. M. [Physics Department, Technion-Israel Institute of Technology, Haifa 32000 (Israel)

    2014-04-14

    The layered compound BaCo{sub 1−x}Ni{sub x}S{sub 2−y} (0.05 < x < 0.2 and 0.05 < y < 0.2) exhibits an unusual first-order structural and electronic phase transition from a low-T monoclinic paramagnetic metal to a high-T tetragonal antiferromagnetic insulator around 200 K with huge hysteresis (∼40 K) and large volume change (∼0.01). Here, we report on unusual voltage-controlled resistive switching followed by current-controlled resistive switching induced by self-heating in polycrystalline BaCo{sub 1−x}Ni{sub x}S{sub 2−y} (nominal x = 0.1 and y = 0.2). These were due to the steep metal to insulator transition upon heating followed by the activated behavior of the resistivity above the transition. The major role of Joule heating in switching is supported by the absence of nonlinearity in the current as function of voltage, I(V), obtained in pulsed measurements, in the range of electric fields relevant to d.c. measurements. The voltage-controlled negative differential resistance around the threshold for switching was explained by a simple model of self-heating. The main difficulty in modeling I(V) from the samples resistance as function of temperature R(T) was the progressive increase of R(T), and to a lesser extend the decrease of the resistance jumps at the transitions, caused by the damage induced by cycling through the transitions by heating or self-heating. This was dealt with by following systematically R(T) over many cycles and by using the data of R(T) in the heating cycle closest to that of the self-heating one.

  13. Optimal Cut-Offs of Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) to Identify Dysglycemia and Type 2 Diabetes Mellitus: A 15-Year Prospective Study in Chinese.

    Science.gov (United States)

    Lee, C H; Shih, A Z L; Woo, Y C; Fong, C H Y; Leung, O Y; Janus, E; Cheung, B M Y; Lam, K S L

    The optimal reference range of homeostasis model assessment of insulin resistance (HOMA-IR) in normal Chinese population has not been clearly defined. Here we address this issue using the Hong Kong Cardiovascular Risk Factor Prevalence Study (CRISPS), a prospective population-based cohort study with long-term follow-up. In this study, normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM) were defined according to the 1998 World Health Organization criteria. Dysglycemia referred to IFG, IGT or T2DM. This study comprised two parts. Part one was a cross-sectional study involving 2,649 Hong Kong Chinese subjects, aged 25-74 years, at baseline CRISPS-1 (1995-1996). The optimal HOMA-IR cut-offs for dysglycemia and T2DM were determined by the receiver-operating characteristic (ROC) curve. Part two was a prospective study involving 872 subjects who had persistent NGT at CRISPS-4 (2010-2012) after 15 years of follow-up. At baseline, the optimal HOMA-IR cut-offs to identify dysglyceia and T2DM were 1.37 (AUC = 0.735; 95% confidence interval [CI] = 0.713-0.758; Sensitivity [Se] = 65.6%, Specificity [Sp] = 71.3%] and 1.97 (AUC = 0.807; 95% CI = 0.777-0.886; Se = 65.5%, Sp = 82.9%) respectively. These cut-offs, derived from the cross-sectional study at baseline, corresponded closely to the 75th (1.44) and 90th (2.03) percentiles, respectively, of the HOMA-IR reference range derived from the prospective study of subjects with persistent NGT. HOMA-IR cut-offs, of 1.4 and 2.0, which discriminated dysglycemia and T2DM respectively from NGT in Southern Chinese, can be usefully employed as references in clinical research involving the assessment of insulin resistance.

  14. Adiposidade corporal, mas não resistência insulínica, associa-se ao polimorfismo -675 4G/5G no gene PAI-1 em uma amostra de crianças mexicanas

    Directory of Open Access Journals (Sweden)

    Ulises de la Cruz-Mosso

    2013-10-01

    Full Text Available OBJETIVO: Elaboramos este estudo para avaliar se o polimorfismo -675 4G/5G no gene inibidor 1 do ativador do plasminogênio se associa à obesidade e à resistência insulínica em crianças mexicanas. MÉTODOS: Foi realizado um estudo transversal em 174 crianças, 89 delas com peso normal e 85 obesas, variando sua idade de 6 a 13 anos. Todas as crianças eram do estado de Guerrero e foram recrutadas de três escolas primárias na cidade de Chilpancingo, México. Os níveis de insulina foram determinados por prova imunoenzimática. Foi usado o modelo de avaliação da homeostase para determinar resistência insulínica. O polimorfismo -675 4G/5G no gene PAI-1 foi analisado pelo método reação de polimerase em cadeia-polimorfismo no comprimento dos fragmentos de restrição. RESULTADOS: A prevalência de resistência insulínica no grupo obeso foi mais alta (49,41% do que no grupo com peso normal (16,85%. O polimorfismo 4G/5G do PAI-1 foi encontrado em equilíbrio de Hardy Weinberg. O genótipo 4G/5G contribuiu para um aumento significativo da relação cintura-quadril (β = 0,02, p = 0,006, da circunferência da cintura (β = 4,42, p = 0,009 e da espessura da prega subescapular (β = 1,79, p = 0,04, mas não se relacionou com a resistência insulínica. CONCLUSÃO: O genótipo -675 4G/5G do gene PAI-1 se associou a aumento da adiposidade corporal em crianças mexicanas.

  15. Myostatin induces insulin resistance via Casitas B-lineage lymphoma b (Cblb)-mediated degradation of insulin receptor substrate 1 (IRS1) protein in response to high calorie diet intake.

    Science.gov (United States)

    Bonala, Sabeera; Lokireddy, Sudarsanareddy; McFarlane, Craig; Patnam, Sreekanth; Sharma, Mridula; Kambadur, Ravi

    2014-03-14

    To date a plethora of evidence has clearly demonstrated that continued high calorie intake leads to insulin resistance and type-2 diabetes with or without obesity. However, the necessary signals that initiate insulin resistance during high calorie intake remain largely unknown. Our results here show that in response to a regimen of high fat or high glucose diets, Mstn levels were induced in muscle and liver of mice. High glucose- or fat-mediated induction of Mstn was controlled at the level of transcription, as highly conserved carbohydrate response and sterol-responsive (E-box) elements were present in the Mstn promoter and were revealed to be critical for ChREBP (carbohydrate-responsive element-binding protein) or SREBP1c (sterol regulatory element-binding protein 1c) regulation of Mstn expression. Further molecular analysis suggested that the increased Mstn levels (due to high glucose or fatty acid loading) resulted in increased expression of Cblb in a Smad3-dependent manner. Casitas B-lineage lymphoma b (Cblb) is an ubiquitin E3 ligase that has been shown to specifically degrade insulin receptor substrate 1 (IRS1) protein. Consistent with this, our results revealed that elevated Mstn levels specifically up-regulated Cblb, resulting in enhanced ubiquitin proteasome-mediated degradation of IRS1. In addition, over expression or knock down of Cblb had a major impact on IRS1 and pAkt levels in the presence or absence of insulin. Collectively, these observations strongly suggest that increased glucose levels and high fat diet, both, result in increased circulatory Mstn levels. The increased Mstn in turn is a potent inducer of insulin resistance by degrading IRS1 protein via the E3 ligase, Cblb, in a Smad3-dependent manner.

  16. Development of signal processing electronics for self powered neutron detector signal with built-in on-line insulation monitoring [Paper No.:E3

    International Nuclear Information System (INIS)

    Das, Amitabha; Chaganty, S.P.

    1993-01-01

    Self powered neutron detectors (SPNDs) are employed to monitor in-core neutron flux in nuclear reactors for control, safety and mapping of in-core neutron flux. The d.c. current produced by SPND is converted into a proportional d.c. voltage, which in turn is used for various purposes stated above. This paper describes various features of the SPND amplifier developed in the Electronics Division of Bhabha Atomic Research Centre (BARC). It also outlines the principle of working of on-line monitoring of insulation resistance (IR) of the detector and associated mineral insulated (MI) and soft cables. The amplifier generates an alarm in case of the IR of the detector and the cable assembly falls below an accepted value or the cable is not connected to the amplifier and relieves the operator from periodic and manual checking of each of the individual detectors and ensures the validity of the signal for further processing. (author). 3 figs

  17. Structural, electronic and magnetic properties of the series of double perovskites (Ca,Sr){sub 2−x}La{sub x}FeIrO{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Bufaiçal, L., E-mail: lbufaical@ufg.br [Instituto de Física, Universidade Federal de Goiás, 74001-970 Goiânia, GO (Brazil); Adriano, C. [Instituto de Física “Gleb Wataghin”, UNICAMP, 13083-859 Campinas, SP (Brazil); Lora-Serrano, R. [Instituto de Física, Universidade Federal de Uberlândia, 38400-902 Uberlândia, MG (Brazil); Duque, J.G.S. [Núcleo de Física, Universidade Federal de Sergipe, Campus Itabaiana, 49500-000 Itabaiana, SE (Brazil); Mendonça-Ferreira, L. [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, 09210-170 Santo André, SP (Brazil); Rojas-Ayala, C.; Baggio-Saitovitch, E.; Bittar, E.M. [Centro Brasileiro de Pesquisas Físicas, 22290-180 Rio de Janeiro, RJ (Brazil); Pagliuso, P.G. [Instituto de Física “Gleb Wataghin”, UNICAMP, 13083-859 Campinas, SP (Brazil)

    2014-04-01

    Polycrystalline samples of the series of double perovskites Sr{sub 2−x}La{sub x}FeIrO{sub 6} were synthesized. Their structural, electronic and magnetic properties were investigated by X-ray powder diffraction, Mössbauer spectroscopy, magnetic susceptibility, heat capacity and electrical resistivity experiments. The compounds crystallize in a monoclinic structure and were fitted in space group P2{sub 1}/n, with a significant degree of Fe/Ir cationic disorder. As in Ca{sub 2−x}La{sub x}FeIrO{sub 6} the Sr-based system seems to evolve from an antiferromagnetic ground state for the end members (x=0.0 and x=2.0) to a ferrimagnetic order in the intermediate regions (x∼1). Since Mössbauer spectra indicate that Fe valence remains 3+ with doping, this tendency of change in the nature of the microscopic interaction could be attributed to Ir valence changes, induced by La{sup 3+} electrical doping. Upon comparing both Ca and Sr series, Sr{sub 2−x}La{sub x}FeIrO{sub 6} is more structurally homogenous and presents higher magnetization and transition temperatures. Magnetic susceptibility measurements at high temperatures on Sr{sub 1.2}La{sub 0.8}FeIrO{sub 6} indicate a very high ferrimagnetic Curie temperature T{sub C}∼700K. For the Sr{sub 2}FeIrO{sub 6} compound, electrical resistivity experiments under applied pressure suggest that this material might be a Mott insulator. - Graphical abstract: The Weiss constant as a function of La doping for the (Ca,Sr){sub 2−x}La{sub x}FeIrO{sub 6} series, indicating changes in Fe–Ir magnetic coupling on both families. - Highlights: • The double perovskite series (Ca,Sr){sub 2−x}La{sub x}FeIrO{sub 6} were synthesized. • Changes in the Fe-Ir magnetic coupling due to La doping on both series. • Evidence of high T{sub C} on Sr{sub 1.2}La{sub 0.8}FeIrO{sub 6}. • Indication of Mott insulator behavior on Sr{sub 2}FeIrO{sub 6}.

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  19. Improved DC Gun Insulator Assembly

    International Nuclear Information System (INIS)

    Neubauer, M.L.; Dudas, A.; Sah, R.; Poelker, M.; Surles-Law, K.E.L.

    2010-01-01

    Many user facilities such as synchrotron radiation light sources and free electron lasers require accelerating structures that support electric fields of 10-100 MV/m, especially at the start of the accelerator chain where ceramic insulators are used for very high gradient DC guns. These insulators are difficult to manufacture, require long commissioning times, and often exhibit poor reliability. Two technical approaches to solving this problem will be investigated. Firstly, inverted ceramics offer solutions for reduced gradients between the electrodes and ground. An inverted design will be presented for 350 kV, with maximum gradients in the range of 5-10 MV/m. Secondly, novel ceramic manufacturing processes will be studied, in order to protect triple junction locations from emission, by applying a coating with a bulk resistivity. The processes for creating this coating will be optimized to provide protection as well as be used to coat a ceramic with an appropriate gradient in bulk resistivity from the vacuum side to the air side of an HV standoff ceramic cylinder. Example insulator designs are being computer modelled, and insulator samples are being manufactured and tested

  20. Higher glucose, insulin and insulin resistance (HOMA-IR) in childhood predict adverse cardiovascular risk in early adulthood: the Pune Children's Study.

    Science.gov (United States)

    Yajnik, Chittaranjan S; Katre, Prachi A; Joshi, Suyog M; Kumaran, Kalyanaraman; Bhat, Dattatray S; Lubree, Himangi G; Memane, Nilam; Kinare, Arun S; Pandit, Anand N; Bhave, Sheila A; Bavdekar, Ashish; Fall, Caroline H D

    2015-07-01

    The Pune Children's Study aimed to test whether glucose and insulin measurements in childhood predict cardiovascular risk factors in young adulthood. We followed up 357 participants (75% follow-up) at 21 years of age who had undergone detailed measurements at 8 years of age (glucose, insulin, HOMA-IR and other indices). Oral glucose tolerance, anthropometry, plasma lipids, BP, carotid intima-media thickness (IMT) and arterial pulse wave velocity (PWV) were measured at 21 years. Higher fasting glucose, insulin and HOMA-IR at 8 years predicted higher glucose, insulin, HOMA-IR, BP, lipids and IMT at 21 years. A 1 SD change in 8 year variables was associated with a 0.10-0.27 SD change at 21 years independently of obesity/adiposity at 8 years of age. A greater rise in glucose-insulin variables between 8 and 21 years was associated with higher cardiovascular risk factors, including PWV. Participants whose HOMA-IR measurement remained in the highest quartile (n = 31) had a more adverse cardiovascular risk profile compared with those whose HOMA-IR measurement remained in the lowest quartile (n = 28). Prepubertal glucose-insulin metabolism is associated with adult cardiovascular risk and markers of atherosclerosis. Our results support interventions to improve glucose-insulin metabolism in childhood to reduce cardiovascular risk in later life.

  1. Foam insulated transfer line test report

    International Nuclear Information System (INIS)

    Squier, D.M.

    1994-06-01

    Miles of underground insulated piping will be installed at the Hanford site to transfer liquid waste. Significant cost savings may be realized by using pre-fabricated polyurethane foam insulated piping. Measurements were made on sections of insulated pipe to determine the insulation's resistance to axial expansion of the pipe, the force required to compress the foam in the leg of an expansion loop and the time required for heat up and cool down of a buried piping loop. These measurements demonstrated that the peak axial force increases with the amount of adhesion between the encasement pipe and the insulation. The compressive strength of the foam is too great to accommodate the thermal growth of long straight pipe sections into the expansion loops. Mathematical models of the piping system's thermal behavior can be refined by data from the heated piping loop

  2. Experimental demonstration on the ultra-low source/drain resistance by metal-insulator-semiconductor contact structure in In0.53Ga0.47As field-effect transistors

    Directory of Open Access Journals (Sweden)

    M.-H. Liao

    2013-09-01

    Full Text Available In this work, we demonstrate the ultra-low contact resistivity of 6.7 × 10−9 Ω/cm2 by inserting 0.6-nm-ZnO between Al and InGaAs(Si: 1.5 × 1019 cm−3. The metal-insulator-semiconductor tunneling diode with 0.6-nm-ZnO exhibits nearly zero (0.03 eV barrier height. We apply this contact structure on the source/drain of implant-free In0.53Ga0.47As quantum-well metal-oxide-semiconductor field- effect transistors. The excellent on-state performance such as saturation drain current of 3 × 10−4 A/μm and peak transconductance of 1250 μS/μm is obtained which is attributed to the ultra-low source/drain resistance of 190 Ω-μm.

  3. Fibroblast Growth Factor 21 (FGF21, Free Fatty Acid (FFA, High Sensitivity C-reactive Protein (hsCRP and Homeostasis Model Assessment of Insulin Resistance (HOMA-IR Among Indonesian Obese Non-Diabetic Males

    Directory of Open Access Journals (Sweden)

    Yani Lina

    2009-12-01

    Full Text Available BACKGROUND: Fibroblast growth factor-21 (FGF21 is known as an important endocrine and paracrine regulator of metabolic homeostasis. Recent studies have shown that FGF21 attenuates lipolysis in human adipocytes, which is suggested as a FGF21's mechanism as anti-hyperlipidemia, anti-hyperglycemia and anti-obesity. The aim of this study was to measure the correlation between FGF21, FFA, hsCRP and HOMA-IR among Indonesian obese non diabetic males. METHODS: The study was observational with cross sectional design. The analysis was done in 137 subjects aged 30-60 years with non diabetic abdominal obesity. We measured the biochemical markers FGF21, FFA, hsCRP, fasting insulin and fasting glucose. We also measured weight, height, waist circumrefence (WC, creatinine, serum glutamin oxaloacetic transaminase (SGOT, and serum glutamic pyruvic transaminase (SGPT, systolic blood pressure (SBP and diastolic blood pressure (DBP. Correlation between markers was measured using Pearson and Spearman's analysis. RESULTS: There were significant positive correlations between FGF21-HOMA-IR (r=0.314, p=0.000; FGF21-WC (r=0.173, p=0.043; FFA=hsCRP r=0.270, p=0.001; and WC-HOMA-IR (r=0.279, p=0.001. There was significant negative correlation between FGF21-FFA (r=-0.038, p=0.657 and FGF21-hsCRP (r=-0.061, p=0.482. CONCLUSIONS: In this study we found that although there was no significant correlation, FGF21 might act as an anti-lipolytic and anti-inflammation agent among Indonesian obese non-diabetic males. Our findings agree with results of previous studies that the positive correlation between FGF21-WC and FGF21-HOMA-IR might occur as a compensatory mechanism or resistance to FGF21 in obesity. KEYWORDS: obesity, FGF21, FFA, hsCRP, HOMA-IR.

  4. The Relationship of Fetuin-A, Adiponectin, Retinol Binding Protein-4 (RBP-4 and High Sensitivity C-Reactive Protein (hsCRP with Insulin Resistance (HOMA-IR in Obese Non Diabetic Men

    Directory of Open Access Journals (Sweden)

    Imelda Novianti

    2012-04-01

    Full Text Available BACKGROUND: Central obesity is the accumulation of visceral (intra-abdominal fat and is strongly known to be associated with insulin resistance and type 2 diabetes mellitus (T2DM. Obesity can cause adipocyte hypertrophy that results in dysregulation of adipokine expression. The abnormal function of adipocytes may play an important role in the development of a chronic low-grade proinflammatory state associated with obesity. Adiponectin, retinol binding protein (RBP-4 and fetuin-A play a role in the pathophysiology of insulin resistance. Expression of fetuin-A is increased due to fat accumulation in the liver. Elevated concentration of fetuin-A in the circulation can impair insulin signaling in muscle and liver as well as suppress adiponectin secretion, although its molecular mechanism is still unclear. The aim of this study was to identify the relationship of fetuin-A, adiponectin, RBP-4 and hsCRP with insulin resistance in obese non diabetic men. METHODS: This was an observational study with a cross-sectional design. The study subjects were 64 men with non diabetic abdominal obesity, characterized by waist circumference of 98.47±5.88 cm and fasting blood glucose of 85.75±8.36 mg/dL. RESULTS: This study showed that fetuin-A was positively correlated with HOMA-IR in obese non diabetic men with insulin resistance (r=0.128; p=0.570, although not significant. Fetuin-A was found to be correlated with adiponectin, RBP-4 and hsCRP (r=0.150; p=0.233; r=0.050; p=0.711; r=-0.04; p=0.445, although not significant. CONCLUSIONS: The concentration of fetuin-A showed a tendency to be positively correlated with HOMA-IR and with RBP-4 in obese non diabetic men, although statistically not significant. The concentration of fetuin-A showed a tendency to be negatively correlated with adiponectin and hsCRP although statistically not significant. There was no interrelationship between fetuin-A, adiponectin, RBP-4, hsCRP and HOMA-IR. Elevated concentrations of fetuin

  5. Analysis and comparison of magnetic sheet insulation tests

    Science.gov (United States)

    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.

  6. Economically optimal thermal insulation

    Energy Technology Data Exchange (ETDEWEB)

    Berber, J.

    1978-10-01

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

  7. Metal-insulator transition upon heating and negative-differential-resistive-switching induced by self-heating in BaCo0.9Ni0.1S1.8

    International Nuclear Information System (INIS)

    Fisher, B.; Genossar, J.; Chashka, K. B.; Patlagan, L.; Reisner, G. M.

    2014-01-01

    The layered compound BaCo 1−x Ni x S 2−y (0.05  1−x Ni x S 2−y (nominal x = 0.1 and y = 0.2). These were due to the steep metal to insulator transition upon heating followed by the activated behavior of the resistivity above the transition. The major role of Joule heating in switching is supported by the absence of nonlinearity in the current as function of voltage, I(V), obtained in pulsed measurements, in the range of electric fields relevant to d.c. measurements. The voltage-controlled negative differential resistance around the threshold for switching was explained by a simple model of self-heating. The main difficulty in modeling I(V) from the samples resistance as function of temperature R(T) was the progressive increase of R(T), and to a lesser extend the decrease of the resistance jumps at the transitions, caused by the damage induced by cycling through the transitions by heating or self-heating. This was dealt with by following systematically R(T) over many cycles and by using the data of R(T) in the heating cycle closest to that of the self-heating one

  8. Optimal cut-off of homeostasis model assessment of insulin resistance (HOMA-IR) for the diagnosis of metabolic syndrome: third national surveillance of risk factors of non-communicable diseases in Iran (SuRFNCD-2007).

    Science.gov (United States)

    Esteghamati, Alireza; Ashraf, Haleh; Khalilzadeh, Omid; Zandieh, Ali; Nakhjavani, Manouchehr; Rashidi, Armin; Haghazali, Mehrdad; Asgari, Fereshteh

    2010-04-07

    We have recently determined the optimal cut-off of the homeostatic model assessment of insulin resistance for the diagnosis of insulin resistance (IR) and metabolic syndrome (MetS) in non-diabetic residents of Tehran, the capital of Iran. The aim of the present study is to establish the optimal cut-off at the national level in the Iranian population with and without diabetes. Data of the third National Surveillance of Risk Factors of Non-Communicable Diseases, available for 3,071 adult Iranian individuals aging 25-64 years were analyzed. MetS was defined according to the Adult Treatment Panel III (ATPIII) and International Diabetes Federation (IDF) criteria. HOMA-IR cut-offs from the 50th to the 95th percentile were calculated and sensitivity, specificity, and positive likelihood ratio for MetS diagnosis were determined. The receiver operating characteristic (ROC) curves of HOMA-IR for MetS diagnosis were depicted, and the optimal cut-offs were determined by two different methods: Youden index, and the shortest distance from the top left corner of the curve. The area under the curve (AUC) (95%CI) was 0.650 (0.631-0.670) for IDF-defined MetS and 0.683 (0.664-0.703) with the ATPIII definition. The optimal HOMA-IR cut-off for the diagnosis of IDF- and ATPIII-defined MetS in non-diabetic individuals was 1.775 (sensitivity: 57.3%, specificity: 65.3%, with ATPIII; sensitivity: 55.9%, specificity: 64.7%, with IDF). The optimal cut-offs in diabetic individuals were 3.875 (sensitivity: 49.7%, specificity: 69.6%) and 4.325 (sensitivity: 45.4%, specificity: 69.0%) for ATPIII- and IDF-defined MetS, respectively. We determined the optimal HOMA-IR cut-off points for the diagnosis of MetS in the Iranian population with and without diabetes.

  9. Thermal insulating panel

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, J.T.

    1985-09-11

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

  10. Field evaluation of reflective insulation in south east Asia

    Science.gov (United States)

    Teh, Khar San; Yarbrough, David W.; Lim, Chin Haw; Salleh, Elias

    2017-12-01

    The objective of this research was to obtain thermal performance data for reflective insulations in a South East Asia environment. Thermal resistance data (RSI, m2 ṡ K/W) for reflective insulations are well established from 1-D steady-state tests, but thermal data for reflective insulation in structures like those found in South East Asia are scarce. Data for reflective insulations in South East Asia will add to the worldwide database for this type of energy-conserving material. RSI were obtained from heat flux and temperature data of three identical structures in the same location. One unit did not have insulation above the ceiling, while the second and third units were insulated with reflective insulation with emittance less than 0.05. RSI for the uninsulated test unit varied from 0.37 to 0.40 m2 ṡ K/W. RSI for a single-sheet reflective insulation (woven foil) varied from 2.15 to 2.26 m2 ṡ K/W, while bubble-foil insulation varied from 2.69 to 3.09 m2 ṡ K/W. The range of RSI values resulted from differences in the spacing between the reflective insulation and the roof. In addition, the reflective insulation below the roof lowered attic temperatures by as much as 9.7° C. Reductions in ceiling heat flux of 80 to 90% relative to the uninsulated structure, due to the reflective insulation, were observed.

  11. Accelerating dynamic genetic conservation efforts: Use of FT-IR spectroscopy for the rapid identification of trees resistant to destructive pathogens

    Science.gov (United States)

    C. Villari; R.A. Sniezko; L.E. Rodriguez-Saona; P. Bonello

    2017-01-01

    A strong focus on tree germplasm that can resist threats such as non-native insects and pathogens, or a changing climate, is fundamental for successful genetic conservation efforts. However, the unavailability of tools for rapid screening of tree germplasm for resistance to critical pathogens and insect pests is becoming an increasingly serious bottleneck. Here we...

  12. Design of Chern insulating phases in honeycomb lattices

    Science.gov (United States)

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

    2018-06-01

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

  13. Design and construction of the mineral insulated magnets

    International Nuclear Information System (INIS)

    Kurokawa, S.; Hirabayashi, H.; Taino, M.; Tsuchiya, K.; Yamamoto, A.

    1978-01-01

    The radiation resistant magnets with mineral insulated coils are designed and constructed. The electrical insulation of the cable is maintained by magnesium oxide in the form of a powder held around the copper hollow conductor by a copper shieth. By the direct water cooling through a hollow conductor the sometimes conflicting requirements of good insulation and high field are fulfilled. The magnets can with stand more than 10 12 rad of absorbed dose. (author)

  14. Analysis of effect of cable degradation on SPND IR calculation

    International Nuclear Information System (INIS)

    Tamboli, P.K.; Sharma, A.; Prasad, A.D.; Singh, Nita; Antony, J.; Kelkar, M.G.; Kaurav, Reetesh; Pramanik, M.

    2013-01-01

    Neutron flux is the most vital parameter in the nuclear reactor safety against Neutronic over power. The modern days Indian PHWRs with large core size are loosely coupled reactors and hence In-core Self Power Neutron Detectors (SPNDs) are most suitable for monitoring local neutron power for generating Regional Overpower Trip. However the SPNDs and its Mineral Insulation Cable are prone to IR loss due to use of ceramic insulation which are highly hygroscopic. The present paper covers the online analysis of IR f degraded cable as per the surveillance requirement of monitoring the IR to assess the healthiness of SPNDs which are part of SSC/SSE for Reactor Protection Systems. The paper also proposes an alternative method for monitoring IR for startup//low power range when SPND signals are yet to pick up and Reactor Control and Protection are based on out of core Ionization Chambers. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-08-01

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

  16. Panels of microporous insulation

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-08-07

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

  17. Wall insulation system

    Energy Technology Data Exchange (ETDEWEB)

    Kostek, P.T.

    1987-08-11

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

  18. Thermography Control of Heat Insulation and Tightness of Buildings,

    Science.gov (United States)

    1980-11-01

    construction. The method is pedagogical . Results from thermography studies are suitable for use when giving experience feedback. (Excellent complement...visual inspection Instrument Various tools and measures. Principle The construction is opened, and the workmanship of insulation and tight- ness is...most IR cameras. At -196 C (77K) it is sensitive within the wavelength range 0 - 5.6 jam. The lower - 24 - FIGURE 3: Photography with IR camera, AGA

  19. First-principles study on cubic pyrochlore iridates Y2Ir2O7 and Pr2Ir2O7

    International Nuclear Information System (INIS)

    Ishii, Fumiyuki; Mizuta, Yo Pierre; Kato, Takehiro; Ozaki, Taisuke; Weng Hongming; Onoda, Shigeki

    2015-01-01

    Fully relativistic first-principles electronic structure calculations based on a noncollinear local spin density approximation (LSDA) are performed for pyrochlore iridates Y 2 Ir 2 O 7 and Pr 2 Ir 2 O 7 . The all-in, all-out antiferromagnetic (AF) order is stablized by the on-site Coulomb repulsion U > U c in the LSDA+U scheme, with U c ∼ 1.1 eV and 1.3 eV for Y 2 Ir 2 O 7 and Pr 2 Ir 2 O 7 , respectively. AF semimetals with and without Weyl points and then a topologically trivial AF insulator successively appear with further increasing U. For U = 1.3 eV, Y 2 Ir 2 O 7 is a topologically trivial narrow-gap AF insulator having an ordered local magnetic moment ∼0.5μ B /Ir, while Pr 2 Ir 2 O 7 is barely a paramagnetic semimetal with electron and hole concentrations of 0.016/Ir, in overall agreements with experiments. With decreasing oxygen position parameter x describing the trigonal compression of IrO 6 octahedra, Pr 2 Ir 2 O 7 is driven through a non-Fermi-liquid semimetal having only an isolated Fermi point of Γ 8 + , showing a quadratic band touching, to a Z 2 topological insulator. (author)

  20. Inhibition of p70S6K1 Activation by Pdcd4 Overcomes the Resistance to an IGF-1R/IR Inhibitor in Colon Carcinoma Cells.

    Science.gov (United States)

    Zhang, Yan; Wang, Qing; Chen, Li; Yang, Hsin-Sheng

    2015-03-01

    Agents targeting insulin-like growth factor 1 receptor (IGF-1R) are being actively examined in clinical trials. Although there has been some initial success of single-agent targeting IGF-1R, attempts in later studies failed because of resistance. This study aimed to understand the effects of programmed cell death 4 (Pdcd4) on the chemosensitivity of the IGF-1R inhibitor OSI-906 in colorectal cancer cells and the mechanism underlying this impact. Using OSI-906-resistant and -sensitive colorectal cancer cells, we found that the Pdcd4 level directly correlates with cell chemosensitivity to OSI-906. In addition, tumors derived from Pdcd4 knockdown cells resist the growth inhibitory effect of OSI-906 in a colorectal cancer xenograft mouse model. Moreover, Pdcd4 enhances the antiproliferative effect of OSI-906 in resistant cells through suppression of p70S6K1 activation. Knockdown of p70S6K1, but not p70S6K2, significantly increases the chemosensitivity of OSI-906 in cultured colorectal cancer cells. Furthermore, the combination of OSI-906 and PF-4708671, a p70S6K1 inhibitor, efficiently suppresses the growth of OSI-906-resistant colon tumor cells in vitro and in vivo. Taken together, activation of p70S6K1 that is inhibited by Pdcd4 is essential for resistance to the IGF-1R inhibitor in colon tumor cells, and the combinational treatment of OSI-906 and PF-4708671 results in enhanced antiproliferation effects in colorectal cancer cells in vitro and in vivo, providing a novel venue to overcome the resistance to the IGF-1R inhibitor in treating colorectal cancer. ©2015 American Association for Cancer Research.

  1. A Prospective Cohort Study on IRS Gene Polymorphisms in Type 2 ...

    African Journals Online (AJOL)

    Insulin resistance status was determined using the homeostatic model assessment for insulin resistance (HOMA-IR) index. Results: IRS1 polymorphisms were associated with increased insulin resistance (X2 = 5.09, p = 0.023) in T2DM patients with severe/acute hyperglycemia. IRS2 polymorphisms were not associated with ...

  2. Inhibition of p70S6K1 activation by Pdcd4 overcomes the resistance to an IGF-1R/IR inhibitor in colon carcinoma cells

    OpenAIRE

    Zhang, Yan; Wang, Qing; Chen, Li; Yang, Hsin-Sheng

    2015-01-01

    Agents targeting insulin-like growth factor 1 receptor (IGF-1R) are being actively examined in clinical trials. Although there has been some initial success of single agent targeting IGF-1R, attempts in later studies failed due to resistance. This study aimed to understand the effects of programmed cell death 4 (Pdcd4) on the chemosensitivity of the IGF-1R inhibitor, OSI-906, in colorectal cancer (CRC) cells and the mechanism underlying this impact. Using OSI-906 resistant and sensitive CRC c...

  3. Large power factor and anomalous Hall effect and their correlation with observed linear magneto resistance in Co-doped Bi2Se3 3D topological insulator

    Science.gov (United States)

    Singh, Rahul; Shukla, K. K.; Kumar, A.; Okram, G. S.; Singh, D.; Ganeshan, V.; Lakhani, Archana; Ghosh, A. K.; Chatterjee, Sandip

    2016-09-01

    Magnetoresistance (MR), thermo power, magnetization and Hall effect measurements have been performed on Co-doped Bi2Se3 topological insulators. The undoped sample shows that the maximum MR as a destructive interference due to a π-Berry phase leads to a decrease of MR. As the Co is doped, the linearity in MR is increased. The observed MR of Bi2Se3 can be explained with the classical model. The low temperature MR behavior of Co doped samples cannot be explained with the same model, but can be explained with the quantum linear MR model. Magnetization behavior indicates the establishment of ferromagnetic ordering with Co doping. Hall effect data also supports the establishment of ferromagnetic ordering in Co-doped Bi2Se3 samples by showing the anomalous Hall effect. Furthermore, when spectral weight suppression is insignificant, Bi2Se3 behaves as a dilute magnetic semiconductor. Moreover, the maximum power factor is observed when time reversal symmetry (TRS) is maintained. As the TRS is broken the power factor value is decreased, which indicates that with the rise of Dirac cone above the Fermi level the anomalous Hall effect and linearity in MR increase and the power factor decreases.

  4. Charge transport through superconductor/Anderson-insulator interfaces

    International Nuclear Information System (INIS)

    Frydman, A.; Ovadyahu, Z.

    1997-01-01

    We report on a study of charge transport through superconductor-insulator-superconductor and normal metal endash insulator endash superconductor structures (SIS and NIS junctions, respectively) where the insulator is of the Anderson type. Devices which are characterized by a junction resistance larger than 10 kΩ show behavior which is typical of Giaever tunnel junctions. In structures having smaller resistance, several peculiar features are observed. In the SIS junctions, Josephson coupling is detected over distances much larger then the typical insulator localization length. In addition, a series of resistance peaks appears at voltages of 2Δ/n, where Δ is the superconducting gap. The NIS Junctions exhibit a large resistance dip at subgap bias. We discuss possible interpretations of these findings and suggest that they may result from the presence of high transmission channels through the barrier region. copyright 1997 The American Physical Society

  5. Translucent insulating building envelope

    DEFF Research Database (Denmark)

    Rahbek, Jens Eg

    1997-01-01

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

  6. Sound Insulation between Dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2011-01-01

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

  7. Lipid and insulin infusion-induced skeletal muscle insulin resistance is likely due to metabolic feedback and not changes in IRS-1, Akt, or AS160 phosphorylation.

    Science.gov (United States)

    Hoy, Andrew J; Brandon, Amanda E; Turner, Nigel; Watt, Matthew J; Bruce, Clinton R; Cooney, Gregory J; Kraegen, Edward W

    2009-07-01

    Type 2 diabetes is characterized by hyperlipidemia, hyperinsulinemia, and insulin resistance. The aim of this study was to investigate whether acute hyperlipidemia-induced insulin resistance in the presence of hyperinsulinemia was due to defective insulin signaling. Hyperinsulinemia (approximately 300 mU/l) with hyperlipidemia or glycerol (control) was produced in cannulated male Wistar rats for 0.5, 1 h, 3 h, or 5 h. The glucose infusion rate required to maintain euglycemia was significantly reduced by 3 h with lipid infusion and was further reduced after 5 h of infusion, with no difference in plasma insulin levels, indicating development of insulin resistance. Consistent with this finding, in vivo skeletal muscle glucose uptake (31%, P muscle diacylglyceride and ceramide content over the same time course. However, there was an increase in cumulative exposure to long-chain acyl-CoA (70%) with lipid infusion. Interestingly, although muscle pyruvate dehydrogenase kinase 4 protein content was decreased in hyperinsulinemic glycerol-infused rats, this decrease was blunted in muscle from hyperinsulinemic lipid-infused rats. Decreased pyruvate dehydrogenase complex activity was also observed in lipid- and insulin-infused animals (43%). Overall, these results suggest that acute reductions in muscle glucose metabolism in rats with hyperlipidemia and hyperinsulinemia are more likely a result of substrate competition than a significant early defect in insulin action or signaling.

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

    Science.gov (United States)

    Hess, David M.

    2013-01-01

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

  9. Effect of oxygen vacancies on magnetic and transport properties of Sr2IrO4

    Science.gov (United States)

    Dwivedi, Vinod Kumar; Mukhopadhyay, Soumik

    2018-05-01

    Iridates have recently attracted growing interest because of their potential for realizing various interesting phases like interaction driven Mott-type insulator and magnetically driven Slater-type. In this paper, we present the magnetic and electrical transport properties of polycrystalline Sr2IrO4 synthesized by solid state reaction route. We find a ferromagnetic transition at 240 K. The Curie-Weiss law behavior hold good above the magnetic transition temperature TMag = 240 K with a small effective paramagnetic magnetic moment μeff = 0.25 µB/f.u. and a Curie-Weiss temperature, θCW = +100 K. Zero field cooled (ZFC) magnetization shows a gradual dcrease below 150 K, while same for field cooled (FC) below 50 K. Interestingly, below temperatures, ⁓ 10 K, a sharp increase in ZFC and FC magnetization can be seen. A temperature dependent resistivity reveals insulating behavior followed by power law mechanism. The sintering of sample in air leads to the very low value of resistivity is likely related to Sr or oxygen vacancies.

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

    CERN Document Server

    International Electrotechnical Commission. Geneva

    2004-01-01

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

  11. Topological Insulator Nanowires and Nanoribbons

    KAUST Repository

    Kong, Desheng

    2010-01-13

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

  12. Heat insulation support device

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  13. Vacuum foil insulation system

    International Nuclear Information System (INIS)

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

    1976-01-01

    In a multifoil thermal insulation package having a plurality of concentric cylindrical cups, means are provided for reducing heat loss from the penetration region which extends through the cups. At least one cup includes an integral skirt extending from one end of the cup to intersection with the penetration means. Assembly of the insulation package with the skirted cup is facilitated by splitting the cup to allow it to be opened up and fitted around the other cups during assembly. The insulation is for an implantable nuclear powered artificial heart

  14. Suppression of superconductivity in Nb by IrMn in IrMn/Nb bilayers

    KAUST Repository

    Wu, B. L.

    2013-10-10

    Effect of antiferromagnet on superconductivity has been investigated in IrMn/Nb bilayers. Significant suppression of both transition temperature (Tc) and lower critical field (Hc1) of Nb is found in IrMn/Nb bilayers as compared to a single layer Nb of same thickness; the suppression effect is even stronger than that of a ferromagnet in NiFe/Nb bilayers. The addition of an insulating MgO layer at the IrMn-Nb interface nearly restores Tc to that of the single layer Nb, but Hc1 still remains suppressed. These results suggest that, in addition to proximity effect and magnetic impurity scattering, magnetostatic interaction also plays a role in suppressing superconductivity of Nb in IrMn/Nb bilayers. In addition to reduced Tc and Hc1, the IrMn layer also induces broadening in the transition temperature of Nb, which can be accounted for by a finite distribution of stray field from IrMn.

  15. Gas insulated substations

    CERN Document Server

    2014-01-01

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

  16. Modeling small-signal response of GaN-based metal-insulator-semiconductor high electron mobility transistor gate stack in spill-over regime: Effect of barrier resistance and interface states

    International Nuclear Information System (INIS)

    Capriotti, M.; Fleury, C.; Oposich, M.; Bethge, O.; Strasser, G.; Pogany, D.; Lagger, P.; Ostermaier, C.

    2015-01-01

    We provide theoretical and simulation analysis of the small signal response of SiO 2 /AlGaN/GaN metal insulator semiconductor (MIS) capacitors from depletion to spill over region, where the AlGaN/SiO 2 interface is accumulated with free electrons. A lumped element model of the gate stack, including the response of traps at the III-N/dielectric interface, is proposed and represented in terms of equivalent parallel capacitance, C p , and conductance, G p . C p -voltage and G p -voltage dependences are modelled taking into account bias dependent AlGaN barrier dynamic resistance R br and the effective channel resistance. In particular, in the spill-over region, the drop of C p with the frequency increase can be explained even without taking into account the response of interface traps, solely by considering the intrinsic response of the gate stack (i.e., no trap effects) and the decrease of R br with the applied forward bias. Furthermore, we show the limitations of the conductance method for the evaluation of the density of interface traps, D it , from the G p /ω vs. angular frequency ω curves. A peak in G p /ω vs. ω occurs even without traps, merely due to the intrinsic frequency response of gate stack. Moreover, the amplitude of the G p /ω vs. ω peak saturates at high D it , which can lead to underestimation of D it . Understanding the complex interplay between the intrinsic gate stack response and the effect of interface traps is relevant for the development of normally on and normally off MIS high electron mobility transistors with stable threshold voltage

  17. Wrapped Multilayer Insulation

    Science.gov (United States)

    Dye, Scott A.

    2015-01-01

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

  18. IOT Overview: IR Instruments

    Science.gov (United States)

    Mason, E.

    In this instrument review chapter the calibration plans of ESO IR instruments are presented and briefly reviewed focusing, in particular, on the case of ISAAC, which has been the first IR instrument at VLT and whose calibration plan served as prototype for the coming instruments.

  19. Survey of thermal insulation systems

    International Nuclear Information System (INIS)

    Kinoshita, Izumi

    1983-01-01

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

  20. Decoupling of magnetism and electric transport in single-crystal (Sr1‑x A x )2IrO4 (A  =  Ca or Ba)

    Science.gov (United States)

    Zhao, H. D.; Terzic, J.; Zheng, H.; Ni, Y. F.; Zhang, Y.; Ye, Feng; Schlottmann, P.; Cao, G.

    2018-06-01

    We report a systematical structural, transport and magnetic study of Ca or Ba doped Sr2IrO4 single crystals. Isoelectronically substituting Ca2+ (up to 15%) or Ba2+ (up to 4%) ion for the Sr2+ ion provides no additional charge carriers but effectively changes the lattice parameters in Sr2IrO4. In particular, 15% Ca doping considerably reduces the c-axis and the unit cell by nearly 0.45% and 1.00%, respectively. These significant, anisotropic compressions in the lattice parameters conspicuously cause no change in the Néel temperature which remains at 240 K, but drastically reduces the electrical resistivity by up to five orders of magnitude or even precipitates a sharp insulator-to-metal transition at lower temperatures, i.e. the vanishing insulating state accompanies an unchanged Néel temperature in (Sr1‑x A x )2IrO4. This observation brings to light an intriguing difference between chemical pressure and applied pressure, the latter of which does suppress the long-range magnetic order in Sr2IrO4. This difference reveals the importance of the Ir1–O2–Ir1 bond angle and homogenous volume compression in determining the magnetic ground state. All results, along with a comparison drawn with results of Tb and La doped Sr2IrO4, underscore that the magnetic transition plays a nonessential role in the formation of the charge gap in the spin–orbit-tuned iridate.

  1. Cladding Attachment Over Thick Exterior Insulating Sheathing

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P. [Building Science Corporation, Somerville, MA (United States); Eng, P. [Building Science Corporation, Somerville, MA (United States); Lepage, R. [Building Science Corporation, Somerville, MA (United States)

    2014-01-01

    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 system 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?

  2. Similarity Analysis of Cable Insulations by Chemical Test

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Seog [Central Research Institute of Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2013-10-15

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials.

  3. Similarity Analysis of Cable Insulations by Chemical Test

    International Nuclear Information System (INIS)

    Kim, Jong Seog

    2013-01-01

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials

  4. Tests on irradiated magnet-insulator materials

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  5. Reusable Surface Insulation

    Science.gov (United States)

    1997-01-01

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

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

    Science.gov (United States)

    Mestnikov, A.

    2015-01-01

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

  7. Cellulose insulation as an air barrier

    Energy Technology Data Exchange (ETDEWEB)

    Manning, K.

    1989-10-01

    The objective of this study was to determine if a wet sprayed cellulose wall insulation system would function satisfactorily without use of a polyethylene air/vapour barrier. The research was designed to demonstrate that this particular insulation system would form enough of a barrier to air leakage, that moisture accumulation from condensation and vapour diffusion would be insignificant. Field work conducted in Alberta, involved construction of a conventional duplex housing unit which was insulated with wet sprayed cellulose in the exterior walls and dry loose-fill cellulose in the attic areas. One half of the unit did not have a polyethylene air/vapor barrier installed. Air leakage and exterior wall moisture levels were monitored for a year following construction. Data collected during this time indicated that the moisture added to the walls during the insulating process was dissipated over the study period. The presence of polyethylene sheeting had no significant effect on the moisture levels in either the wall or attic areas of the test structure. On the other hand, testing indicated that the use of polyethylene sheeting in the wall system did serve to improve blower door air test results. In conclusion, although the air leakage resistance apparently provided by the polyethylene sheeting is significant, the amount is probably not more than could otherwise be obtained by more careful attention to sealing procedures such as those used in the airtight drywall technique. A more important finding is that the use of polyethylene sheeting is not essential in a structure which has the degree of air leakage resistance provided by the insulation system used in this project. 6 figs., 2 tabs.

  8. Beyond insulation and isolation

    DEFF Research Database (Denmark)

    Højlund, Marie Koldkjær

    2016-01-01

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

  9. Self-Healing Wire Insulation

    Science.gov (United States)

    Parrish, Clyde F. (Inventor)

    2012-01-01

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

  10. Thermal insulation product for insulation, especially in nuclear power engineering, and method of its production

    International Nuclear Information System (INIS)

    Veselovsky, P.; Zink, S.; Balacek, P.; Mares, I.

    1989-01-01

    The insulation consists of a sewn fabric cover made of inorganic fibers, in which the fiber filling is reinforced mechanically by dense point interweaving. The inorganic fibers, 1 to 5 μm in diameter, consist of min. 97 wt.% mixture of aluminium and silicon oxides in the vitreous state. The fibers making up the cover consist of min. 95% silicon, aluminium, calcium, magnesium and boron oxides in the vitreous state; the rest can consist of alloy steel fibres. The bulk density of the insulation is 70 to 150 kg/m 3 . The product is highly resistant to temperature and to the action of chemicals, water, and acid and alkaline deactivation solutions. Its manufacture is fast and undemanding. It is designed for thermal insulation of pipes, tanks and valves in nuclear power plants. (M.D.). 2 figs

  11. Integrated Multilayer Insulation

    Science.gov (United States)

    Dye, Scott

    2009-01-01

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

  12. Interfacial Coatings for Inorganic Composite Insulation Systems

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  13. Radiation effects on insulators for superconducting magnets

    International Nuclear Information System (INIS)

    Kernohan, R.H.; Coltman, R.R. Jr.; Long, C.J.

    1978-01-01

    In order to determine the radiation stability of electrical insulation that could be used in a superconducting magnet for containment of the plasma in a fusion energy device, 55 specimens of eight types of organic insulation were irradiated to a dose of about 2 x 10 8 R (2 x 10 6 J/Kg) at a temperature of 4.8 K in the Low-Temperature Irradiation Facility in the Bulk Shielding Reactor at Oak Ridge National Laboratory. Four of the specimens were monitored for changes in electrical resistivity during the irradiation. The initial resistivities, which were of the order of 10 14 Ω cm, decreased to about 10 13 Ω cm under the influence of a weak radiation field. At full-power reactor operation (2 MW), the resistivities dropped to about 10 11 Ω cm, but changed little during the irradiation. After the irradiation the resistivities increased, but not to the initial values, because of residual radioactivity near or in the experiment assembly. Restoration to near the initial resistivity values was later observed upon warming the specimens to room temperature and purging the irradiation chamber. The latter result may be related to outgassing induced by the irradiation

  14. Semiconductor of spinons: from Ising band insulator to orthogonal band insulator.

    Science.gov (United States)

    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.

  15. Semiconductor of spinons: from Ising band insulator to orthogonal band insulator

    Science.gov (United States)

    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.

  16. Improving the reliability of stator insulation system in rotating machines

    International Nuclear Information System (INIS)

    Gupta, G.K.; Sedding, H.G.; Culbert, I.M.

    1997-01-01

    Reliable performance of rotating machines, especially generators and primary heat transport pump motors, is critical to the efficient operation on nuclear stations. A significant number of premature machine failures have been attributed to the stator insulation problems. Ontario Hydro has attempted to assure the long term reliability of the insulation system in critical rotating machines through proper specifications and quality assurance tests for new machines and periodic on-line and off-line diagnostic tests on machines in service. The experience gained over the last twenty years is presented in this paper. Functional specifications have been developed for the insulation system in critical rotating machines based on engineering considerations and our past experience. These specifications include insulation stress, insulation resistance and polarization index, partial discharge levels, dissipation factor and tip up, AC and DC hipot tests. Voltage endurance tests are specified for groundwall insulation system of full size production coils and bars. For machines with multi-turn coils, turn insulation strength for fast fronted surges in specified and verified through tests on all coils in the factory and on samples of finished coils in the laboratory. Periodic on-line and off-line diagnostic tests were performed to assess the condition of the stator insulation system in machines in service. Partial discharges are measured on-line using several techniques to detect any excessive degradation of the insulation system in critical machines. Novel sensors have been developed and installed in several machines to facilitate measurements of partial discharges on operating machines. Several off-line tests are performed either to confirm the problems indicated by the on-line test or to assess the insulation system in machines which cannot be easily tested on-line. Experience with these tests, including their capabilities and limitations, are presented. (author)

  17. Síndrome metabólica em crianças obesas e fatores de risco para doenças cardiovasculares de acordo com a resistência à insulina (HOMA-IR Metabolic syndrome and risk factors for cardiovascular disease in obese children: the relationship with insulin resistance (HOMA-IR

    Directory of Open Access Journals (Sweden)

    Aparecido Pimentel Ferreira

    2007-02-01

    Full Text Available OBJETIVO: Verificar a prevalência da síndrome metabólica e identificar fatores de risco para desenvolvimento de doenças cardiovasculares de acordo com a resistência à insulina. MÉTODOS: Realizou-se um estudo transversal em 52 crianças obesas. A amostra foi randomizada após avaliação do índice de massa corporal [peso (kg/estatura (m²] de 1.550 escolares. A obesidade foi definida quando esse índice se encontrava acima do percentil 95 da classificação do Centers for Disease Control and Prevention. O sangue de jejum foi utilizado para mensurar a glicemia, lipoproteínas de alta densidade, triglicerídeos e insulina. A gordura corporal foi avaliada pela absortometria de raio X de dupla energia. A pressão arterial e a resistência à insulina foram mensuradas. A síndrome metabólica foi definida segundo o critério do National Cholesterol Education Program, com pontos de corte ajustados para a idade da amostra. RESULTADOS: A síndrome metabólica esteve presente em 17,3% das crianças avaliadas. A resistência à insulina diferiu significativamente entre o sexo feminino (3,8±2,2; IC95% 2,9-4,8 e o sexo masculino (2,6±1,3; IC95% 2,1-3,1; p = 0,016. Cerca de 44,2% da amostra apresentou pelo menos dois fatores de risco, e 15% apresentou hipertensão arterial. A hipertrigliceridemia foi encontrada em 50 e 70,8% dos meninos e meninas, respectivamente. Os níveis de lipoproteínas de alta densidade abaixo do desejável foram encontrados somente nas meninas. CONCLUSÕES: Crianças obesas apresentaram alta prevalência de síndrome metabólica. Apresentaram mais fatores de risco aquelas que obtiveram maiores níveis de resistência à insulina. Desta forma, são necessárias medidas intervencionistas com intuito de barrar o ganho de peso durante a infância.OBJECTIVE: To identify the prevalence of metabolic syndrome and risk factors for the development of cardiovascular diseases and to investigate their relationship with insulin resistance

  18. Heat insulating plates

    Energy Technology Data Exchange (ETDEWEB)

    Allan, J.A.F.

    1976-10-28

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

  19. Super-insulation

    International Nuclear Information System (INIS)

    Gerold, J.

    1985-01-01

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

  20. Compact vacuum insulation embodiments

    Science.gov (United States)

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

    1992-04-28

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

  1. Compact vacuum insulation

    Science.gov (United States)

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

    1993-01-05

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

  2. Insulating materials for optoelectronics

    International Nuclear Information System (INIS)

    Agullo-Lopez, F.

    1990-01-01

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

  3. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken

    2004-01-01

    form the weakest part of the thermal envelope with respect to heat loss coefficient, but on the other hand also play an important role for passive solar energy utilisation. For window orientations other than south, the net energy balance will be close to or below zero. However, the properties......Monolithic silica aerogel offers the possibility of combining super insulation and high solar energy transmittance, which has been the background for a previous and a current EU project on research and development of monolithic silica aerogel as transparent insulation in windows. Generally, windows...... of aerogel glazing will allow for a positive net energy gain even for north facing vertical windows in a Danish climate during the heating season. This means that high quality daylight can be obtained even with additional energy gain. On behalf of the partners of the two EU projects, results related...

  4. Insulated pipe clamp design

    International Nuclear Information System (INIS)

    Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

    1980-01-01

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. 5 refs

  5. Pourable Foam Insulation

    Science.gov (United States)

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

    1989-01-01

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

  6. Effects of radiation on insulation materials

    International Nuclear Information System (INIS)

    Poehlchen, R.

    1992-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Omer Kaynakli

    2011-06-01

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

  8. Aerogel-Based Insulation for Industrial Steam Distribution Systems

    Energy Technology Data Exchange (ETDEWEB)

    John Williams

    2011-03-30

    Thermal losses in industrial steam distribution systems account for 977 trillion Btu/year in the US, more than 1% of total domestic energy consumption. Aspen Aerogels worked with Department of Energy’s Industrial Technologies Program to specify, develop, scale-up, demonstrate, and deliver Pyrogel XT®, an aerogel-based pipe insulation, to market to reduce energy losses in industrial steam systems. The product developed has become Aspen’s best selling flexible aerogel blanket insulation and has led to over 60 new jobs. Additionally, this product has delivered more than ~0.7 TBTU of domestic energy savings to date, and could produce annual energy savings of 149 TBTU by 2030. Pyrogel XT’s commercial success has been driven by it’s 2-4X better thermal performance, improved durability, greater resistance to corrosion under insulation (CUI), and faster installation times than incumbent insulation materials.

  9. Isothermal anisotropic magnetoresistance in antiferromagnetic metallic IrMn.

    Science.gov (United States)

    Galceran, R; Fina, I; Cisneros-Fernández, J; Bozzo, B; Frontera, C; López-Mir, L; Deniz, H; Park, K-W; Park, B-G; Balcells, Ll; Martí, X; Jungwirth, T; Martínez, B

    2016-10-20

    Antiferromagnetic spintronics is an emerging field; antiferromagnets can improve the functionalities of ferromagnets with higher response times, and having the information shielded against external magnetic field. Moreover, a large list of aniferromagnetic semiconductors and metals with Néel temperatures above room temperature exists. In the present manuscript, we persevere in the quest for the limits of how large can anisotropic magnetoresistance be in antiferromagnetic materials with very large spin-orbit coupling. We selected IrMn as a prime example of first-class moment (Mn) and spin-orbit (Ir) combination. Isothermal magnetotransport measurements in an antiferromagnetic-metal(IrMn)/ferromagnetic-insulator thin film bilayer have been performed. The metal/insulator structure with magnetic coupling between both layers allows the measurement of the modulation of the transport properties exclusively in the antiferromagnetic layer. Anisotropic magnetoresistance as large as 0.15% has been found, which is much larger than that for a bare IrMn layer. Interestingly, it has been observed that anisotropic magnetoresistance is strongly influenced by the field cooling conditions, signaling the dependence of the found response on the formation of domains at the magnetic ordering temperature.

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

    Science.gov (United States)

    Achtliger, J.

    1983-09-01

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

  11. Electrical insulating liquid: A review

    Directory of Open Access Journals (Sweden)

    Deba Kumar Mahanta

    2017-08-01

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

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

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  13. Irradiation effects on organic insulators

    International Nuclear Information System (INIS)

    Kasen, M.B.

    1986-01-01

    The overall objective of this work is to contribute to development of organic insulators having the cryogenic neutron irradiation resistance required for MFE systems utilizing superconducting magnet confinement. The system for producing standard 3.2-mm (0.125-in) diameter rod specimens discussed in previous reports has been further refined to permit the fabrication of both fiber-reinforced and heat-resin specimens from hot-melt resin systems. The method has been successfully used to produce very high quality specimens duplicating the G-11CR system and specimens from a variant of that system eliminating a boron-containing additive. We have also produced specimens from an epoxy system suitable for impregnation or potting operations and from a bismaleimide polyimide system. These materials will be used in the first irradiation program in the National Low Temperature Neutron Irradiation Facility (NLTNIF) reactor at Oak Ridge. We have refined the 4-K torsional shear test method for evaluating radiation degradation of the fiber-matrix interface and have developed a method of quantitatively measuring changes in fracture energy as a function of radiation dose. Cooperative work with laboratories in Japan and England in this area is continuing and plans are being formulated for joint production, irradiation, and testing of specimens

  14. Magnetically insulated H- diodes

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  15. Role of IRS-2 in insulin and cytokine signalling.

    Science.gov (United States)

    Sun, X J; Wang, L M; Zhang, Y; Yenush, L; Myers, M G; Glasheen, E; Lane, W S; Pierce, J H; White, M F

    1995-09-14

    The protein IRS-1 acts as an interface between signalling proteins with Src-homology-2 domains (SH2 proteins) and the receptors for insulin, IGF-1, growth hormone, several interleukins (IL-4, IL-9, IL-13) and other cytokines. It regulates gene expression and stimulates mitogenesis, and appears to mediate insulin/IGF-1-stimulated glucose transport. Thus, survival of the IRS-1-/- mouse with only mild resistance to insulin was surprising. This dilemma is provisionally resolved with our discovery of a second IRS-signalling protein. We purified and cloned a likely candidate called 4PS from myeloid progenitor cells and, because of its resemblance to IRS-1, we designate it IRS-2. Alignment of the sequences of IRS-2 and IRS-1 revealed a highly conserved amino terminus containing a pleckstrin-homology domain and a phosphotyrosine-binding domain, and a poorly conserved carboxy terminus containing several tyrosine phosphorylation motifs. IRS-2 is expressed in many cells, including tissues from IRS-1-/- mice, and may be essential for signalling by several receptor systems.

  16. Studies on Kondo insulating FeSi

    International Nuclear Information System (INIS)

    Bharathi, A.; Mani, Awadhesh; Ravindran, Nithya; Mathi Jaya, S.; Sundar, C.S.; Hariharan, Y.

    2000-01-01

    Temperature dependent electrical resistivity measurements have been carried out in Fe (1-x) Ru x Si and FeSi (1-x) Ge x to examine the robustness of the Kondo Insulating gap to substitution in the Fe and Si sublattices. The gap is seen to decrease with Ge substitution, while for Ru substitution the gap shows an initial decrease followed by an increase at higher concentration. The results can be understood in terms of the shift in the mobility edge due to disorder and/or pressure effects in combination with changes in band structure

  17. Improved cable insulation for superconducting magnets

    International Nuclear Information System (INIS)

    Anerella, M.; Ghosh, A.K.; Kelly, E.; Schmalzle, J.; Willen, E.; Fraivillig, J.; Ochsner, J.; Parish, D.J.

    1993-01-01

    Several years ago, Brookhaven joined with DuPont in a cooperative effort to develop improved cable insulation for SSC superconducting dipole magnets. The effort was supported by the SSC Central Design Group and later the SSC Laboratory. It was undertaken because turn-to-turn and midplane shorts were routinely being experienced during the assembly of magnets with coils made of the existing Kapton/fiberglass (K/FG) system of Kapton film overwrapped with epoxy-impregnated fiberglass tape. Dissection of failed magnets showed that insulation disruption and punch-through was occurring near the inner edges of turns close to the magnet midplane. Coil pressures of greater than 17 kpsi were sufficient to disrupt the insulation at local high spots where the cable had been strongly compacted in the keystoning operation during cable manufacture. In the joint development program, numerous combinations of polyimide films manufactured by DuPont with varying configurations and properties (including thickness) were subjected to tests at Brookhaven. Early tests were bench trials using wrapped cable samples. The most promising candidates were used in coils and many of these promising candidates were used in coils and many of these assembled and tested as magnets in both the SSC and RHIC magnet programs currently underway. The Kapton CI (CI) system that has been adopted represents a suitable compromise of numerous competing factors. It exhibits improved performance in the critical parameter of compressive punch-through resistance as well as other advantages over the K/FG system

  18. Improved cable insulation for superconducting magnets

    International Nuclear Information System (INIS)

    Anerella, M.; Ghosh, A.K.; Kelly, E.; Schmalzle, J.; Willen, E.; Fraivillig, J.; Ochsner, J.; Parish, D.J.

    1993-01-01

    Several years ago, Brookhaven joined with DuPont in a cooperative effort to develop improved cable insulation for SSC superconducting dipole magnets. The effort was supported by the SSC Central Design Group and later the SSC Laboratory. It was undertaken because turn-to-turn and midplane shorts were routinely being experienced during the assembly of magnets with coils made of the existing Kapton/Fiberglass (K/FG) system of Kapton film overwrapped with epoxy-impregnated fiberglass tape. Dissection of failed magnets showed that insulation disruption and punch-through was occurring near the inner edges of turns close to the magnet midplane. Coil pressures of greater than 17 kpsi were sufficient to disrupt the insulation at local high spots where wires in neighboring turns crossed one another and where the cable had been strongly compacted in the keystoning operation during cable manufacture. In the joint development program, numerous combinations of polyimide films manufactured by DuPont with varying configurations and properties (including thickness) were subjected to tests at Brookhaven. Early tests were bench trials using wrapped cable samples. The most promising candidates were used in coils and many of these assembled and tested as magnets in both the SSC and RHIC magnet programs currently underway. The Kapton CI (CI) system that has been adopted represents a suitable compromise of numerous competing factors. It exhibits improved performance in the critical parameter of compressive punch-through resistance as well as other advantages over the K/FG system

  19. Phase coexistence in the metal-insulator transition of a VO2 thin film

    International Nuclear Information System (INIS)

    Chang, Y.J.; Koo, C.H.; Yang, J.S.; Kim, Y.S.; Kim, D.H.; Lee, J.S.; Noh, T.W.; Kim, Hyun-Tak; Chae, B.G.

    2005-01-01

    Vanadium dioxide (VO 2 ) shows a metal-insulator transition (MIT) near room temperature, accompanied by an abrupt resistivity change. Since the MIT of VO 2 is known to be a first order phase transition, it is valuable to check metallic and insulating phase segregation during the MIT process. We deposited (100)-oriented epitaxial VO 2 thin films on R-cut sapphire substrates. From the scanning tunneling spectroscopy (STS) spectra, we could distinguish metallic and insulating regions by probing the band gap. Optical spectroscopic analysis also supported the view that the MIT in VO 2 occurs through metal and insulator phase coexistence

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

    NARCIS (Netherlands)

    Krakers, L.A.

    2009-01-01

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

  1. Reentrant Metal-Insulator Transitions in Silicon -

    Science.gov (United States)

    Campbell, John William M.

    This thesis describes a study of reentrant metal -insulator transitions observed in the inversion layer of extremely high mobility Si-MOSFETs. Magneto-transport measurements were carried out in the temperature range 20mK-4.2 K in a ^3He/^4 He dilution refrigerator which was surrounded by a 15 Tesla superconducting magnet. Below a melting temperature (T_{M}~500 mK) and a critical electron density (n_{s }~9times10^{10} cm^{-2}), the Shubnikov -de Haas oscillations in the diagonal resistivity enormous maximum values at the half filled Landau levels while maintaining deep minima corresponding to the quantum Hall effect at filled Landau levels. At even lower electron densities the insulating regions began to spread and eventually a metal-insulator transition could be induced at zero magnetic field. The measurement of extremely large resistances in the milliKelvin temperature range required the use of very low currents (typically in the 10^ {-12} A range) and in certain measurements minimizing the noise was also a consideration. The improvements achieved in these areas through the use of shielding, optical decouplers and battery operated instruments are described. The transport signatures of the insulating state are considered in terms of two basic mechanisms: single particle localization with transport by variable range hopping and the formation of a collective state such as a pinned Wigner crystal or electron solid with transport through the motion of bound dislocation pairs. The experimental data is best described by the latter model. Thus the two dimensional electron system in these high mobility Si-MOSFETs provides the first and only experimental demonstration to date of the formation of an electron solid at zero and low magnetic fields in the quantum limit where the Coulomb interaction energy dominates over the zero point oscillation energy. The role of disorder in favouring either single particle localization or the formation of a Wigner crystal is explored by

  2. Building America Top Innovations 2013 Profile – Exterior Rigid Insulation Best Practices

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-09-01

    In this Top Innovation profile, field and lab studies by BSC, PHI, and NorthernSTAR characterize the thermal, air, and vapor resistance properties of rigid foam insulation and describe best practices for their use on walls, roofs, and foundations.

  3. Insulation structure of thermonuclear device

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  4. Plastic Materials for Insulating Applications.

    Science.gov (United States)

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

    1987-01-01

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

  5. IR and the Earth

    DEFF Research Database (Denmark)

    Corry, Olaf; Stevenson, Hayley

    2017-01-01

    , in the end, one finite interconnected space. Together these two starting points make for the basic conundrum of Inter- national Relations and the Earth: how does a divided world live on a single globe? This introduction first provides an overview of the recent rise of ‘the environment’ in international......, ‘what has the environment ever done for IR?’, before the plan for the rest of the book sketches the content and direction of the ensuing chapters that explore the problematique of International Relations and the Earth....

  6. External Insulation of Masonry Walls and Wood Framed Walls

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P.

    2013-01-01

    The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1" to 1 1/2"), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

  7. External Insulation of Masonry Walls and Wood Framed Walls

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P. [Building Science Corporation, Somerville, MA (United States)

    2013-01-01

    The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1” to 1 ½”), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

  8. Thermal-Insulation Properties of Multilayer Textile Packages

    Directory of Open Access Journals (Sweden)

    Matusiak Małgorzata

    2014-12-01

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

  9. Insulator layer formation in MgB2 SIS junctions

    International Nuclear Information System (INIS)

    Shimakage, H.; Tsujimoto, K.; Wang, Z.; Tonouchi, M.

    2005-01-01

    The dependence of current-voltage characteristics on thin film deposition conditions was investigated using MgB 2 /AlN/NbN SIS junctions. By increasing the substrate temperature in AlN insulator deposition, the current density decreased and the normal resistance increased. The results indicated that an additional insulator layer between the MgB 2 and AlN formed, either before or during the AlN deposition. The thickness of the additional insulator layer was increased with an increase in the AlN deposition temperature. From the dependence of current density on the thickness of AlN in low temperature depositions, the thickness of the additional insulator layer was estimated to be 1-1.5 nm when the AlN insulator was deposited from 0.14 to 0.7 nm. Moreover, with the current density of MgB 2 /AlN/MgB 2 SIS junctions, further insulator layer formation was confirmed

  10. Thermic insulation in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Nicolaon, G. (Ambassade de France a New York (USA)); Atlas, O. (Illinois Institute of Technology, Chicago, (USA))

    1984-01-30

    At present, thermic insulation accounts for 13% of the savings which have been made and this percentage should increase substantially in the future. The ideal insulation material must have low thermic conductivity, but also be light, have a low dilatation coefficient, good mechanical resistance and be fireproof and non-toxic. Rock wool and above all glass wool have the major portion in the insulation market with about 75% of the total. The prospects for an increase in sales are average: 6 to 7% per year until 1990 with a stabilization or a decrease after this date. Production is concentrated in the hands of about ten producers. The insulation with a cellulose base -with the addition of a combustion inhibitor, usually borax- represent about 15% of the market. Manufacturers are numerous and the production units are small. Any serious evaluation of the future of this product is difficult to make. However, it should be noted that combustion inhibition is one of the main factors of success of this product and constitutes a relatively active field of research. Perlite and vermiculite have a marginal part of the market which is concentrated in the hands of a few dozen producers. Their future seems promising and their production should double between now and the end of the century. There is also the field of plastics which has to be considered and notably polystyrene, polyurethanes and polyisocyanates. These can be injected and moulded in situ. To the extent that toxicity studies can definitively conclude that they are not harmful (urea-formol resins have just been prohibited), their future is brillant and their growth rate could reach about 200% per year. The big chemical and pharmaceutical companies are interested in these products and their portion of the market can rapidly go beyond their present 6 to 8%.

  11. Online Chip Temperature Monitoring Using υce-Load Current and IR Thermography

    DEFF Research Database (Denmark)

    Ghimire, Pramod; Pedersen, Kristian Bonderup; Trintis, Ionut

    2015-01-01

    This paper presents on-state collector-emitter voltage (υce, on)-load current (Ic) method to monitor chip temperature on power insulated gate bipolar transistor (IGBT) modules in converter operation. The measurement method is also evaluated using infrared (IR) thermography. Temperature dependencies...

  12. Magnetically self-insulated transformers

    International Nuclear Information System (INIS)

    Novac, B.M.; Smith, I.R.; Brown, J.

    2002-01-01

    Magnetic insulation is the only practicable form of insulation for much equipment used in ultrahigh pulsed-power work, including transmission lines and plasma opening switches. It has not however so far been successfully exploited in the transformers that are necessarily involved, and the first proposed design that appeared more than 30 years ago raised apparently insuperable problems. The two novel arrangements for a magnetically insulated transformer described in this paper overcome the problems faced by the earlier designs and also offer considerable scope for development in a number of important areas. Theoretical justification is given for their insulating properties, and this is confirmed by proof-of-principle results obtained from a small-scale experimental prototype in which magnetic insulation was demonstrated at up to 100 kV. (author)

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

    Science.gov (United States)

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

    2004-01-01

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

  14. Excitons in insulators

    International Nuclear Information System (INIS)

    Grasser, R.; Scharmann, A.

    1983-01-01

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

  15. Theory of the low-voltage impedance of superconductor-- p insulator--normal metal tunnel junctions

    International Nuclear Information System (INIS)

    Lemberger, T.R.

    1984-01-01

    A theory for the low-voltage impedance of a superconductor-- p insulator--normal metal tunnel junction is developed that includes the effects of charge imbalance and of quasiparticle fluctuations. A novel, inelastic, charge-imbalance relaxation process is identified that is associated with the junction itself. This new process leads to the surprising result that the charge-imbalance component of the dc resistance of a junction becomes independent of the electron-phonon scattering rate as the insulator resistance decreases

  16. Detailed IR aperture measurements

    CERN Document Server

    Bruce, Roderik; Garcia Morales, Hector; Giovannozzi, Massimo; Hermes, Pascal Dominik; Mirarchi, Daniele; Quaranta, Elena; Redaelli, Stefano; Rossi, Carlo; Skowronski, Piotr Krzysztof; Wretborn, Sven Joel; CERN. Geneva. ATS Department

    2016-01-01

    MD 1673 was carried out on October 5 2016, in order to investigate in more detail the available aperture in the LHC high-luminosity insertions at 6.5 TeV and β∗=40 cm. Previous aperture measurements in 2016 during commissioning had shown that the available aperture is at the edge of protection, and that the aperture bottleneck at β∗=40 cm in certain cases is found in the separation plane instead of in the crossing plane. Furthermore, the bottlenecks were consistently found in close to the upstream end of Q3 on the side of the incoming beam, and not in Q2 on the outgoing beam as expected from calculations. Therefore, this MD aimed at measuring IR1 and IR5 separately (at 6.5 TeV and β∗=40 cm, for 185 µrad half crossing angle), to further localize the bottlenecks longitudinally using newly installed BLMs, investigate the difference in aperture between Q2 and Q3, and to see if any aperture can be gained using special orbit bumps.

  17. Catalytic steam methane reforming over Ir/Ce{sub 0.9}Gd{sub 0.1}O{sub 2-x}: resistance to coke formation and sulfur poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Postole, G.; Girona, K.; Kaddouri, A.; Gelin, P. [Institut de Recherches sur la Catalyse et l' Environnement de Lyon, Universite Lyon 1, CNRS, UMR 5256, IRCELYON, F-69626 Villeurbanne Cedex (France); Toyir, J. [Institut de Recherches sur la Catalyse et l' Environnement de Lyon, Universite Lyon 1, CNRS, UMR 5256, IRCELYON, F-69626 Villeurbanne Cedex (France); Universite Sidi Mohamed Ben Abdellah Fes, FP-Taza, B.P. 1223 Taza (Morocco)

    2012-04-15

    This work investigates the catalytic properties of Ir/Ce{sub 0.9}Gd{sub 0.1}O{sub 2-x} (Ir/CGO) catalyst and CGO support in steam reforming of methane in the absence or presence of H{sub 2}S (50 ppm) for further application in a solid oxide fuel cell (SOFC) working under methane at intermediate temperatures and integrating a gradual internal reforming concept. The catalytic activity was measured at 750 C by using a 50 mol.% CH{sub 4}/5 mol.% H{sub 2}O/45 mol.% N{sub 2} mixture and a 10 mol.% CH{sub 4}/90 mol.% N{sub 2} mixture. The addition of Ir to CGO improves the catalytic activity in hydrogen production by two orders of magnitude with respect to that of CGO alone. Temperature programmed oxidation experiments were performed after reaction in both types of mixtures to study the eventual formation of carbon deposits. Over Ir/CGO, carbon formed in little amounts (even in the absence of H{sub 2}O in the feed), being highly reactive toward O{sub 2}. Upon H{sub 2}S addition, the CGO support exhibited surprisingly an improved catalytic activity on the contrary to Ir/CGO which partly deactivated. Upon suppression of H{sub 2}S in the feed the initial catalytic activity was fully restored for both catalysts. The catalytic behavior of CGO in the presence of H{sub 2}S was discussed, based upon temperature programmed reaction of CH{sub 4}. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

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

    Energy Technology Data Exchange (ETDEWEB)

    Thorsell, Thomas

    2012-07-01

    procedure incorporates specific steps exposing the wall to different climate conditions, ranging from cold and dry to hot and humid, with and without a pressure gradient. This study showed that air infiltration alone might decrease the thermal resistance of a residential wall by 15 %, more for industrial walls. Results from the research underpin a discussion concerning the importance of a holistic approach to building design if we are to meet the challenge of energy savings and sustainability. Thermal insulation efficiency is a main concept used throughout, and since it measures utilization it is a partial measure of sustainability. It is therefore proposed as a necessary design parameter in addition to a performance indicator when designing building envelopes. The thermal insulation efficiency ranges from below 50 % for a wood stud wall poorly designed with incorporated VIP, while an optimized design with VIP placed in an uninterrupted external layer shows an efficiency of 99 %, almost perfect. Thermal insulation efficiency reflects the measured wall performance full scale test, thus indicating efficiency under varied environmental loads: heat, moisture and pressure. The building design must be as a system, integrating all the subsystems together to function in concert. New design methodologies must be created along with new, more reliable and comprehensive measuring, testing and integrating procedures. New super insulators are capable of reducing energy usage below zero energy in buildings. It would be a shame to waste them by not taking care of the rest of the system. This thesis details the steps that went into this study and shows how this can be done Key words: Vacuum insulation panels, VIP, serpentine edge, thermal bridge, composite film, gas diffusion, defect dominated, holistic approach, building enclosure, integrated testing and modeling, energy equivalent, field performance, air flow, thermal insulation efficiency.

  19. Compensatory insulin receptor (IR) activation on inhibition of insulin-like growth factor-1 receptor (IGF-1R): rationale for cotargeting IGF-1R and IR in cancer.

    Science.gov (United States)

    Buck, Elizabeth; Gokhale, Prafulla C; Koujak, Susan; Brown, Eric; Eyzaguirre, Alexandra; Tao, Nianjun; Rosenfeld-Franklin, Maryland; Lerner, Lorena; Chiu, M Isabel; Wild, Robert; Epstein, David; Pachter, Jonathan A; Miglarese, Mark R

    2010-10-01

    Insulin-like growth factor-1 receptor (IGF-1R) is a receptor tyrosine kinase (RTK) and critical activator of the phosphatidylinositol 3-kinase-AKT pathway. IGF-1R is required for oncogenic transformation and tumorigenesis. These observations have spurred anticancer drug discovery and development efforts for both biological and small-molecule IGF-1R inhibitors. The ability for one RTK to compensate for another to maintain tumor cell viability is emerging as a common resistance mechanism to antitumor agents targeting individual RTKs. As IGF-1R is structurally and functionally related to the insulin receptor (IR), we asked whether IR is tumorigenic and whether IR-AKT signaling contributes to resistance to IGF-1R inhibition. Both IGF-1R and IR(A) are tumorigenic in a mouse mammary tumor model. In human tumor cells coexpressing IGF-1R and IR, bidirectional cross talk was observed following either knockdown of IR expression or treatment with a selective anti-IGF-1R antibody, MAB391. MAB391 treatment resulted in a compensatory increase in phospho-IR, which was associated with resistance to inhibition of IRS1 and AKT. In contrast, treatment with OSI-906, a small-molecule dual inhibitor of IGF-1R/IR, resulted in enhanced reduction in phospho-IRS1/phospho-AKT relative to MAB391. Insulin or IGF-2 activated the IR-AKT pathway and decreased sensitivity to MAB391 but not to OSI-906. In tumor cells with an autocrine IGF-2 loop, both OSI-906 and an anti-IGF-2 antibody reduced phospho-IR/phospho-AKT, whereas MAB391 was ineffective. Finally, OSI-906 showed superior efficacy compared with MAB391 in human tumor xenograft models in which both IGF-1R and IR were phosphorylated. Collectively, these data indicate that cotargeting IGF-1R and IR may provide superior antitumor efficacy compared with targeting IGF-1R alone.

  20. Use of HOMA-IR in hepatitis C.

    Science.gov (United States)

    Eslam, M; Kawaguchi, T; Del Campo, J A; Sata, M; Khattab, M Abo-Elneen; Romero-Gomez, M

    2011-10-01

    Chronic infection with hepatitis C virus (HCV) can induce insulin resistance (IR) in a genotype-dependent manner and contributes to steatosis, progression of fibrosis and resistance to interferon plus ribavirin therapy. Our understanding of HCV-induced IR has improved considerably over the years, but certain aspects concerning its evaluation still remain elusive to clinical researchers. One of the most important issues is elucidating the ideal method for assessment of IR in the setting of hepatitis C. The hyperinsulinaemic euglycaemic clamp is the gold standard method for determining insulin sensitivity, but is impractical as it is labour intensive and time-consuming. To date, all human studies except for four where IR was evaluated in the HCV setting, an estimation of IR has been used rather than direct measurements of insulin-mediated glucose uptake. The most commonly used estimation in the HCV population is the homeostasis model assessment of insulin resistance (HOMA-IR) which is calculated from a single measurement of fasting insulin and glucose. In this article, we review the use and reporting of HOMA in the literature and provide guidance on its appropriate as well as inappropriate use in the hepatitis setting. © 2011 Blackwell Publishing Ltd.

  1. Topological Oxide Insulator in Cubic Perovskite Structure

    Science.gov (United States)

    Jin, Hosub; Rhim, Sonny H.; Im, Jino; Freeman, Arthur J.

    2013-01-01

    The emergence of topologically protected conducting states with the chiral spin texture is the most prominent feature at the surface of topological insulators. On the application side, large band gap and high resistivity to distinguish surface from bulk degrees of freedom should be guaranteed for the full usage of the surface states. Here, we suggest that the oxide cubic perovskite YBiO3, more than just an oxide, defines itself as a new three-dimensional topological insulator exhibiting both a large bulk band gap and a high resistivity. Based on first-principles calculations varying the spin-orbit coupling strength, the non-trivial band topology of YBiO3 is investigated, where the spin-orbit coupling of the Bi 6p orbital plays a crucial role. Taking the exquisite synthesis techniques in oxide electronics into account, YBiO3 can also be used to provide various interface configurations hosting exotic topological phenomena combined with other quantum phases. PMID:23575973

  2. Development of Ir/Au-TES microcalorimeter

    International Nuclear Information System (INIS)

    Kunieda, Yuichi; Fukuda, Daiji; Ohno, Masashi; Nakazawa, Masaharu; Takahashi, Hiroyuki; Ataka, Manabu; Ohkubo, Masataka; Hirayama, Fuminori

    2004-01-01

    We are developing X-ray microcalorimeters using transition edge sensors (TES) for high resolution x-ray spectroscopy. Microcalorimeters are thermal detectors which measure the energy of an incident x-ray photon using a TES thermometer operated at a sharp transition edge between normal and superconducting states. TES microcalorimeters can achieve faster response than conventional microcalorimeters by keeping the operating point of TES in the transition region through the use of strong negative electrothermal feedback (ETF). We developed a bilayer TES where a normal metal Au was deposited on a superconductor Ir in order to improve the thermal conductivity of the Ir-TES. We investigated resistance-temperature characteristics. As a result, it showed a very sharp transition within 1 mK at the temperature of 110 mK. The energy resolution of 9.4 eV (FWHM) was achieved for a 5899 eV Mn K al line. (author)

  3. Two dimensional topological insulator in quantizing magnetic fields

    Science.gov (United States)

    Olshanetsky, E. B.; Kvon, Z. D.; Gusev, G. M.; Mikhailov, N. N.; Dvoretsky, S. A.

    2018-05-01

    The effect of quantizing magnetic field on the electron transport is investigated in a two dimensional topological insulator (2D TI) based on a 8 nm (013) HgTe quantum well (QW). The local resistance behavior is indicative of a metal-insulator transition at B ≈ 6 T. On the whole the experimental data agrees with the theory according to which the helical edge states transport in a 2D TI persists from zero up to a critical magnetic field Bc after which a gap opens up in the 2D TI spectrum.

  4. Multiple-Nozzle Spray Head Applies Foam Insulation

    Science.gov (United States)

    Walls, Joe T.

    1993-01-01

    Spray head equipped with four-nozzle turret mixes two reactive components of polyurethane and polyisocyanurate foam insulating material and sprays reacting mixture onto surface to be insulated. If nozzle in use becomes clogged, fresh one automatically rotated into position, with minimal interruption of spraying process. Incorporates features recirculating and controlling pressures of reactive components to maintain quality of foam by ensuring proper blend at outset. Also used to spray protective coats on or in ships, aircraft, and pipelines. Sprays such reactive adhesives as epoxy/polyurethane mixtures. Components of spray contain solid-particle fillers for strength, fire retardance, toughness, resistance to abrasion, or radar absorption.

  5. NaIrO3-A pentavalent post-perovskite

    International Nuclear Information System (INIS)

    Bremholm, M.; Dutton, S.E.; Stephens, P.W.; Cava, R.J.

    2011-01-01

    Sodium iridium (V) oxide, NaIrO 3, was synthesized by a high pressure solid state method and recovered to ambient conditions. It is found to be isostructural with CaIrO 3 , the much-studied structural analog of the high-pressure post-perovskite phase of MgSiO 3 . Among the oxide post-perovskites, NaIrO 3 is the first example with a pentavalent cation. The structure consists of layers of corner- and edge-sharing IrO 6 octahedra separated by layers of NaO 8 bicapped trigonal prisms. NaIrO 3 shows no magnetic ordering and resistivity measurements show non-metallic behavior. The crystal structure, electrical and magnetic properties are discussed and compared to known post-perovskites and pentavalent perovskite metal oxides. -- Graphical abstract: Sodium iridium(V) oxide, NaIrO 3 , synthesized by a high pressure solid state method and recovered to ambient conditions is found to crystallize as the post-perovskite structure and is the first example of a pentavalent ABO 3 post-perovskite. Research highlights: → NaIrO 3 post-perovskite stabilized by pressure. → First example of a pentavalent oxide post-perovskite. → Non-metallic and non-magnetic behavior of NaIrO 3 .

  6. Diamagnetism in spinel compound CuIr2S4

    International Nuclear Information System (INIS)

    Yagasaki, K.; Nakama, T.

    2007-01-01

    The diamagnetic susceptibility in CuIr 2 S 4 is independent of temperature up to just below metal-insulator transition temperature. If activation of electrons to higher levels occurs with breaking dimer pairs, the residual electrons at the dimer position and the activated electrons to the anti-bonding orbital make localized free spins giving a Langevin paramagnetism. Assuming no magnetic interaction between the localized free spins, the susceptibility is calculated using the energy gap obtained from the conductivity assumed to be a conventional semiconductor. The calculated results cannot explain the temperature-independent diamagnetism. The real energy gap is too large for thermal electron activation, however, conduction is induced thermally over several orders of magnitude within insulating phase. From the above results, we claimed new conduction mechanism named traveling dimer conduction: dimer shifts its position by electron hopping to neighbor position without electron activation over the energy gap

  7. Insulation system in an integrated motor compressor

    Energy Technology Data Exchange (ETDEWEB)

    Sihvo, V.

    2010-07-01

    A high-speed and high-voltage solid-rotor induction machine provides beneficial features for natural gas compressor technology. The mechanical robustness of the machine enables its use in an integrated motor-compressor. The technology uses a centrifugal compressor, which is mounted on the same shaft with the high-speed electrical machine driving it. No gearbox is needed as the speed is determined by the frequency converter. The cooling is provided by the process gas, which flows through the motor and is capable of transferring the heat away from the motor. The technology has been used in the compressors in the natural gas supply chain in the central Europe. New areas of application include natural gas compressors working at the wellheads of the subsea gas reservoir. A key challenge for the design of such a motor is the resistance of the stator insulation to the raw natural gas from the well. The gas contains water and heavy hydrocarbon compounds and it is far harsher than the sales gas in the natural gas supply network. The objective of this doctoral thesis is to discuss the resistance of the insulation to the raw natural gas and the phenomena degrading the insulation. The presence of partial discharges is analyzed in this doctoral dissertation. The breakdown voltage of the gas is measured as a function of pressure and gap distance. The partial discharge activity is measured on small samples representing the windings of the machine. The electrical field behavior is also modeled by finite element methods. Based on the measurements it has been concluded that the discharges are expected to disappear at gas pressures above 4 - 5 bar. The disappearance of discharges is caused by the breakdown strength of the gas, which increases as the pressure increases. Based on the finite element analysis, the physical length of a discharge seen in the PD measurements at atmospheric pressure was approximated to be 40 - 120 mum. The chemical aging of the insulation when exposed to raw

  8. Reflective Insulation for Energy Conservation in South East Asia

    Science.gov (United States)

    San Teh, Khar; Yarbrough, David W.; Haw Lim, Chin; Salleh, Elias

    2017-05-01

    Thermal resistances have been measured for attic spaces insulated with reflective insulations. Three test units located in Malaysia were instrumented to provide heat flux and temperatures for the calculation of time-average RSI-values (RSI is representing R-value in SI units). The RSI for attics with enclosed reflective air spaces were in the range 2-3 m2·K/W while the uninsulated attics averaged about 0.4 m2·K/W. The RSI-values determined in this project were for heat-flow down, the predominant heat-flow direction for attic spaces in Equatorial regions. The observed thermal resistances due to the installation of the reflective insulation results in an 80-90% annual decrease in the heat transfer across the ceiling. This reduces utility usage for air conditioned units and improved comfort for occupants. The research demonstrates the use of transient data for the determination of thermal insulation performance and usefulness of enclosed reflective air spaces for thermal resistance.

  9. Lightweight, Thermally Insulating Structural Panels

    Science.gov (United States)

    Eisen, Howard J.; Hickey, Gregory; Wen, Liang-Chi; Layman, William E.; Rainen, Richard A.; Birur, Gajanana C.

    1996-01-01

    Lightweight, thermally insulating panels that also serve as structural members developed. Honeycomb-core panel filled with low-thermal-conductivity, opacified silica aerogel preventing convection and minimizes internal radiation. Copper coating on face sheets reduces radiation. Overall thermal conductivities of panels smaller than state-of-art commercial non-structurally-supporting foam and fibrous insulations. On Earth, panels suitable for use in low-air-pressure environments in which lightweight, compact, structurally supporting insulation needed; for example, aboard high-altitude aircraft or in partially evacuated panels in refrigerators.

  10. Reflecting variable opening insulating panel

    International Nuclear Information System (INIS)

    Nungesser, W.T.

    1976-01-01

    A description is given of a reflecting variable opening insulating panel assembly, comprising a static panel assembly of reflecting insulation sheets forming a cavity along one side of the panel and a movable panel opening out by sliding from the cavity of the static panel, and a locking device for holding the movable panel in a position extending from the cavity of the static panel. This can apply to a nuclear reactor of which the base might require maintenance and periodical checking and for which it is desirable to have available certain processes for the partial dismantling of the insulation [fr

  11. Atomically resolved spectroscopic study of Sr.sub.2./sub.IrO.sub.4./sub.: Experiment and theory

    Czech Academy of Sciences Publication Activity Database

    Li, Q.; Cao, G.; Okamoto, S.; Yi, J.; Lin, W.; Sales, B.C.; Yan, J.; Arita, R.; Kuneš, Jan; Kozhevnikov, A.V.; Eguiluz, A.G.; Imada, M.; Gai, Z.; Pan, M.; Mandrus, D.G.

    2013-01-01

    Roč. 3, OCT (2013), s. 1-7 ISSN 2045-2322 R&D Projects: GA ČR GA13-25251S Institutional support: RVO:68378271 Keywords : Sr 2 IrO 4 * scanning tunneling microscopy * Mott insulator * Slater insulator Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 5.078, year: 2013 http://www.nature.com/srep/2013/131029/srep03073/full/srep03073.html

  12. The IRS-1 signaling system.

    Science.gov (United States)

    Myers, M G; Sun, X J; White, M F

    1994-07-01

    Insulin-receptor substrate 1 (IRS-1) is a principal substrate of the receptor tyrosine kinase for insulin and insulin-like growth factor 1, and a substrate for a tyrosine kinase activated by interleukin 4. IRS-1 undergoes multisite tyrosine phosphorylation and mediates downstream signals by 'docking' various proteins that contain Src homology 2 domains. IRS-1 appears to be a unique molecule; however, 4PS, a protein found mainly in hemopoietic cells, may represent another member of this family.

  13. Insulating Behavior in Graphene with Irradiation-induced Lattice Defects

    Science.gov (United States)

    Chen, Jian-Hao; Williams, Ellen; Fuhrer, Michael

    2010-03-01

    We irradiated cleaned graphene on silicon dioxide in ultra-high vacuum with low energy inert gas ions to produce lattice defects [1], and investigated in detail the transition from metallic to insulating temperature dependence of the conductivity as a function of defect density. We measured the low field magnetoresistance and temperature-dependent resistivity in situ and find that weak localization can only account for a small correction of the resistivity increase with decreasing temperature. We will discuss possible origins of the insulating temperature dependent resistivity in defected graphene in light of our recent experiments. [4pt] [1] Jian-Hao Chen, W. G. Cullen, C. Jang, M. S. Fuhrer, E. D. Williams, PRL 102, 236805 (2009)

  14. Intrinsic nanofilamentation in resistive switching

    KAUST Repository

    Wu, Xing; Cha, Dong Kyu; Bosman, Michel; Raghavan, Nagarajan; Migas, Dmitri B.; Borisenko, Victor E.; Zhang, Xixiang; Li, Kun; Pey, Kin-Leong

    2013-01-01

    -chip circuitry and non-volatile memory storage. Here, we provide insight into the mechanisms that govern highly reproducible controlled resistive switching via a nanofilament by using an asymmetric metal-insulator-semiconductor structure. In-situ transmission

  15. Insulation measurement and supervision in live AC and DC unearthed systems

    CERN Document Server

    Olszowiec, Piotr

    2014-01-01

    Low voltage unearthed (IT) AC and DC systems are commonly applied for supply of power and control circuits in industry, transportation, medical objects etc. The main reasons for their use are high reliability and numerous advantages offered by isolating them against ground. Insulation level is a decisive factor for networks operational reliability and safety. Insufficient insulation-to-ground resistance can cause various disturbances. Though ground faults in IT systems do not make networks operation impossible, they may cause severe problems with their safe functioning. In this book the most important issues concerning normal operation and ground fault phenomena are described in concise form. Numerous methods of insulation resistance and capacitance measurement in live circuits are presented. Important other procedures of  these parameters determination based on measurement and calculation are explained and reviews of selected insulation resistance measurement devices as well as earth fault locating systems ...

  16. Insulation measurement and supervision in live AC and DC unearthed systems

    CERN Document Server

    Olszowiec, Piotr

    2013-01-01

    Low voltage unearthed (IT) AC and DC systems are commonly applied for supply of power and control circuits in industry, transportation, medical objects etc. The main reasons for their use are high reliability and numerous advantages offered by isolating them against ground. Insulation level is a decisive factor for networks operational reliability and safety. Insufficient insulation-to-ground resistance can cause various disturbances. Though ground faults in IT systems do not make networks operation impossible, they may cause severe problems with their safe functioning. In this book the most important issues concerning normal operation and ground fault phenomena are described in concise form. Numerous methods of insulation resistance and capacitance measurement in live circuits are presented. Important other procedures of  these parameters determination based on measurement and calculation are explained and reviews of selected insulation resistance measurement devices as well as earth fault locating systems ...

  17. Molecular dewetting on insulators

    International Nuclear Information System (INIS)

    Burke, S A; Topple, J M; Gruetter, P

    2009-01-01

    Recent attention given to the growth and morphology of organic thin films with regard to organic electronics has led to the observation of dewetting (a transition from layer(s) to islands) of molecular deposits in many of these systems. Dewetting is a much studied phenomenon in the formation of polymer and liquid films, but its observation in thin films of the 'small' molecules typical of organic electronics requires additional consideration of the structure of the interface between the molecular film and the substrate. This review covers some key concepts related to dewetting and molecular film growth. In particular, the origins of different growth modes and the thickness dependent interactions which give rise to dewetting are discussed in terms of surface energies and the disjoining pressure. Characteristics of molecular systems which may lead to these conditions, including the formation of metastable interface structures and commensurate-incommensurate phase transitions, are also discussed. Brief descriptions of some experimental techniques which have been used to study molecular dewetting are given as well. Examples of molecule-on-insulator systems which undergo dewetting are described in some detail, specifically perylene derivatives on alkali halides, C 60 on alkali halides, and the technologically important system of pentacene on SiO 2 . These examples point to some possible predicting factors for the occurrence of dewetting, most importantly the formation of an interface layer which differs from the bulk crystal structure. (topical review)

  18. Molecular dewetting on insulators.

    Science.gov (United States)

    Burke, S A; Topple, J M; Grütter, P

    2009-10-21

    Recent attention given to the growth and morphology of organic thin films with regard to organic electronics has led to the observation of dewetting (a transition from layer(s) to islands) of molecular deposits in many of these systems. Dewetting is a much studied phenomenon in the formation of polymer and liquid films, but its observation in thin films of the 'small' molecules typical of organic electronics requires additional consideration of the structure of the interface between the molecular film and the substrate. This review covers some key concepts related to dewetting and molecular film growth. In particular, the origins of different growth modes and the thickness dependent interactions which give rise to dewetting are discussed in terms of surface energies and the disjoining pressure. Characteristics of molecular systems which may lead to these conditions, including the formation of metastable interface structures and commensurate-incommensurate phase transitions, are also discussed. Brief descriptions of some experimental techniques which have been used to study molecular dewetting are given as well. Examples of molecule-on-insulator systems which undergo dewetting are described in some detail, specifically perylene derivatives on alkali halides, C(60) on alkali halides, and the technologically important system of pentacene on SiO(2). These examples point to some possible predicting factors for the occurrence of dewetting, most importantly the formation of an interface layer which differs from the bulk crystal structure.

  19. Insulating fcc YH

    International Nuclear Information System (INIS)

    Molen, S. J. van der; Nagengast, D. G.; Gogh, A. T. M. van; Kalkman, J.; Kooij, E. S.; Rector, J. H.; Griessen, R.

    2001-01-01

    We study the structural, optical, and electrical properties of Mg z Y 1-z switchable mirrors upon hydrogenation. It is found that the alloys disproportionate into essentially pure YH 3-δ and MgH 2 with the crystal structure of YH 3-δ dependent on the Mg concentration z. For 0 3-δ are observed, whereas for z≥0.1 only cubic YH 3-δ is present. Interestingly, cubic YH 3-δ is expanded compared to YH 2 , in disagreement with theoretical predictions. From optical and electrical measurements we conclude that cubic YH 3-δ is a transparent insulator with properties similar to hexagonal YH 3-δ . Our results are inconsistent with calculations predicting fcc YH 3-δ to be metallic, but they are in good agreement with recent GW calculations on both hcp and fcc YH 3 . Finally, we find an increase in the effective band gap of the hydrided Mg z Y 1-z alloys with increasing z. Possibly this is due to quantum confinement effects in the small YH 3 clusters

  20. Topological Insulator Nanowires and Nanoribbons

    KAUST Repository

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

    2010-01-01

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

  1. Measure Guideline: Basement Insulation Basics

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R.; Mantha, P.; Puttagunta, S.

    2012-10-01

    This guideline is intended to describe good practices for insulating basements in new and existing homes, and is intended to be a practical resources for building contractors, designers, and also to homeowners.

  2. Metal-insulator-semiconductor photodetectors.

    Science.gov (United States)

    Lin, Chu-Hsuan; Liu, Chee Wee

    2010-01-01

    The major radiation of the sun can be roughly divided into three regions: ultraviolet, visible, and infrared light. Detection in these three regions is important to human beings. The metal-insulator-semiconductor photodetector, with a simpler process than the pn-junction photodetector and a lower dark current than the MSM photodetector, has been developed for light detection in these three regions. Ideal UV photodetectors with high UV-to-visible rejection ratio could be demonstrated with III-V metal-insulator-semiconductor UV photodetectors. The visible-light detection and near-infrared optical communications have been implemented with Si and Ge metal-insulator-semiconductor photodetectors. For mid- and long-wavelength infrared detection, metal-insulator-semiconductor SiGe/Si quantum dot infrared photodetectors have been developed, and the detection spectrum covers atmospheric transmission windows.

  3. Metal-Insulator-Semiconductor Photodetectors

    Directory of Open Access Journals (Sweden)

    Chu-Hsuan Lin

    2010-09-01

    Full Text Available The major radiation of the Sun can be roughly divided into three regions: ultraviolet, visible, and infrared light. Detection in these three regions is important to human beings. The metal-insulator-semiconductor photodetector, with a simpler process than the pn-junction photodetector and a lower dark current than the MSM photodetector, has been developed for light detection in these three regions. Ideal UV photodetectors with high UV-to-visible rejection ratio could be demonstrated with III-V metal-insulator-semiconductor UV photodetectors. The visible-light detection and near-infrared optical communications have been implemented with Si and Ge metal-insulator-semiconductor photodetectors. For mid- and long-wavelength infrared detection, metal-insulator-semiconductor SiGe/Si quantum dot infrared photodetectors have been developed, and the detection spectrum covers atmospheric transmission windows.

  4. 16 CFR 460.18 - Insulation ads.

    Science.gov (United States)

    2010-01-01

    ... Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES LABELING AND ADVERTISING OF HOME INSULATION § 460.18 Insulation ads. (a) If your ad gives an R-value, you must give the type of insulation and... your ad gives a price, you must give the type of insulation, the R-value at a specific thickness, the...

  5. Unusual metal-insulator transition in disordered ferromagnetic films

    International Nuclear Information System (INIS)

    Muttalib, K.A.; Wölfle, P.; Misra, R.; Hebard, A.F.

    2012-01-01

    We present a theoretical interpretation of recent data on the conductance near and farther away from the metal-insulator transition in thin ferromagnetic Gd films of thickness b≈2-10 nm. For increasing sheet resistances a dimensional crossover takes place from d=2 to d=3 dimensions, since the large phase relaxation rate caused by scattering of quasiparticles off spin wave excitations renders the dephasing length L φ ≲b at strong disorder. The conductivity data in the various regimes obey fractional power-law or logarithmic temperature dependence. One observes weak localization and interaction induced corrections at weaker disorder. At strong disorder, near the metal-insulator transition, the data show scaling and collapse onto two scaling curves for the metallic and insulating regimes. We interpret this unusual behavior as proof of two distinctly different correlation length exponents on both sides of the transition.

  6. Enhancement of giant magnetoimpedance in composite wire with insulator layer

    International Nuclear Information System (INIS)

    Wang, X.Z.; Yuan, W.Z.; Li, X.D.; Ruan, J.Z.; Zhao, Z.J.; Yang, J.X.; Yang, X.L.; Sun, Z.

    2007-01-01

    CuBe/NiFeB and CuBe/Insulator/NiFeB composite wires have been prepared by electroless-deposition. The giant magnetoimpedance (GMI) effect for NiFeB layer with thickness of 3 μm on CuBe core with diameter of 100 μm has been studied. After adding an insulator layer, the maximal GMI ratio of CuBe/Insulator/NiFeB composite wire is much higher than that of CuBe/NiFeB composite wire, and can reach to about 250% at the frequency range of 500 kHz-1 MHz. The results are explained in terms of difference of magnetic structure and different frequency dependence of resistance and reactance of the two kinds of composite wires

  7. Cryogenic foam insulation: Abstracted publications

    Science.gov (United States)

    Williamson, F. R.

    1977-01-01

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

  8. The effects of imperfect insulator coatings on MHD and heat transfer in rectangular duct

    International Nuclear Information System (INIS)

    Ying, A.Y.; Gaizer, A.A.

    1994-01-01

    In self cooled liquid metal blankets, the use of an insulator coating to reduce the flow of the eddy current to the structure leads to a significant reduction in MHD pressure drop. Furthermore, this insulating layer alters the velocity structure by reducing the potential difference between the side wall and boundary layer. The questions which arise are: (1) How the imperfections in the insulator coating affect the velocity profiles and their consequent impacts on heat transfer performance?; and, (2) How much crack can lead to an unacceptable MHD pressure drop? The dynamics of the crack healing in an insulator coating duct is one of the important subjects requiring study. The purpose of this work is to present numerical simulations of fully developed MHD flow and developing heat transfer characteristics in imperfectly insulated ducts, and to quantify the influences of crack locations, sizes and resistivities on 2-D MHD pressure drops. Comparisons of finite element solutions of pressure drops in partially insulated ducts with analytical solutions obtained from a circuit analogy show excellent agreement. In addition, the remarkable side layer velocity profile observed in a laminar MHD flow of a conducting duct gradually diminishes as the resistance of the insulating layer increases. The average side wall Nusselt number drops by a factor of 2 as the duct becomes fully insulated

  9. Structural, magnetic, and electronic transport properties of pyrochlore iridate Pr2Ir2O7

    Science.gov (United States)

    Kumar, Harish; Chaurasia, Rachna; Kumari, Pratibha; Paramanik, A. K.

    2018-04-01

    We have studied the structural, magnetic, and electronic transport properties of pyrochlore iridate Pr2Ir2O7. Structural investigation has been done using x-ray powder diffraction and Rietveld analysis. Pr2Ir2O7 crystallize in cubic crystallographic phase with Fd-3m space group. Temperature dependent magnetization data does not show magnetic bifurcation down to 2 K. Electrical resistivity data of Pr2Ir2O7 exhibits metallic behavior throughout temperature range. Below 50 K, a small rise in resistivity data of Pr2Ir2O7 is observed down to 12 K.

  10. Industrial manufacturing of electric insulators; Fabricacion industrial de aisladores electricos

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Lucia [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    Porcelain is the insulating material more extensively used for electric insulators manufacturing, due to its dielectric properties; nevertheless, it presents fragility problems of manufacture and of resistance to the thermal shock, among others. For this reason studies are being conducted for the substitution of porcelain in the electric insulators manufacturing. In this area, the Instituto de Investigaciones Electricas developed an improved insulating formulation - the polymeric concrete- and an industrial prototype machine for the manufacture of high voltage electric insulators for outdoors use. [Espanol] La porcelana es el material aislante electrico mas utilizado en la elaboracion de aisladores electricos, debido a sus propiedades dielectricas; sin embargo, presenta problemas de fragilidad, de fabricacion y de baja resistencia al choque termico, entre otros. Es por ello que se realizan estudios para sustituir la porcelana en la fabricacion de aisladores electricos. En este campo, el Instituto de Investigaciones Electricas desarrollo una formulacion aislante mejorada -el concreto polimerico- y una maquina prototipo industrial para fabricar aisladores electricos de alto voltaje para uso en exteriores.

  11. Industrial manufacturing of electric insulators; Fabricacion industrial de aisladores electricos

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Lucia [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    Porcelain is the insulating material more extensively used for electric insulators manufacturing, due to its dielectric properties; nevertheless, it presents fragility problems of manufacture and of resistance to the thermal shock, among others. For this reason studies are being conducted for the substitution of porcelain in the electric insulators manufacturing. In this area, the Instituto de Investigaciones Electricas developed an improved insulating formulation - the polymeric concrete- and an industrial prototype machine for the manufacture of high voltage electric insulators for outdoors use. [Espanol] La porcelana es el material aislante electrico mas utilizado en la elaboracion de aisladores electricos, debido a sus propiedades dielectricas; sin embargo, presenta problemas de fragilidad, de fabricacion y de baja resistencia al choque termico, entre otros. Es por ello que se realizan estudios para sustituir la porcelana en la fabricacion de aisladores electricos. En este campo, el Instituto de Investigaciones Electricas desarrollo una formulacion aislante mejorada -el concreto polimerico- y una maquina prototipo industrial para fabricar aisladores electricos de alto voltaje para uso en exteriores.

  12. Avalanches in insulating gases

    International Nuclear Information System (INIS)

    Verhaart, H.F.A.

    1982-01-01

    Avalanches of charged particles in gases are often studied with the ''electrical method'', the measurement of the waveform of the current in the external circuit. In this thesis a substantial improvement of the time resolution of the measuring setup, to be used for the electrical method, is reported. The avalanche is started by an N 2 -laser with a pulse duration of only 0.6 ns. With this laser it is possible to release a high number of primary electrons (some 10 8 ) which makes it possible to obtain sizeable signals, even at low E/p values. With the setup it is possible to analyze current waveforms with a time resolution down to 1.4 ns, determined by both the laser and the measuring system. Furthermore it is possible to distinguish between the current caused by the electrons and the current caused by the ions in the avalanche and to monitor these currents simultaneously. Avalanche currents are measured in N 2 , CO 2 , O 2 , H 2 O, air of varying humidity, SF 6 and SF 6 /N 2 mixtures. Depending on the nature of the gas and the experimental conditions, processes as diffusion, ionization, attachment, detachment, conversion and secondary emission are observed. Values of parameters with which these processes can be described, are derived from an analysis of the current waveforms. For this analysis already published theories and new theories described in this thesis are used. The drift velocity of both the electrons and the ions could be easily determined from measured avalanche currents. Special attention is paid to avalanches in air becasue of the practical importance of air insulation. (Auth.)

  13. Influence of substrate on the performances of semi-insulating GaAs detectors

    CERN Document Server

    Baldini, R; Nava, F; Canali, C; Lanzieri, C

    2000-01-01

    A study of the carrier transport mechanism, the charge collection efficiency and the energy resolution has been carried out on semi-insulating GaAs X-ray detectors realised on substrates with concentrations of acceptor dopants N sub a , varying from 10 sup 1 sup 4 to 10 sup 1 sup 7 cm sup - sup 3. The electron collection efficiency (ECE) and the reverse current were found to decrease with increasing N sub a , while the resistivity of the material was found to increase. At room temperature, the best collection efficiency (95%) and the best energy resolution (13.7 keV FWHM) for 59.5 keV X-rays of the sup 2 sup 4 sup 1 Am source, have been achieved with the less doped detectors (N sub a approx 10 sup 1 sup 4 cm sup - sup 3). The concentrations of ionised EL2 sup + , determined by optical measurements in IR regions, was shown to increase with N sub a and to be quasi-inversely proportional to the ECE values. This behaviour strongly supports the hypothesis that the EL2 defects play a main role in the compensation o...

  14. Two-Magnon Raman Scattering and Pseudospin-Lattice Interactions in Sr_{2}IrO_{4} and Sr_{3}Ir_{2}O_{7}.

    Science.gov (United States)

    Gretarsson, H; Sung, N H; Höppner, M; Kim, B J; Keimer, B; Le Tacon, M

    2016-04-01

    We have used Raman scattering to investigate the magnetic excitations and lattice dynamics in the prototypical spin-orbit Mott insulators Sr_{2}IrO_{4} and Sr_{3}Ir_{2}O_{7}. Both compounds exhibit pronounced two-magnon Raman scattering features with different energies, line shapes, and temperature dependencies, which in part reflect the different influence of long-range frustrating exchange interactions. Additionally, we find strong Fano asymmetries in the line shapes of low-energy phonon modes in both compounds, which disappear upon cooling below the antiferromagnetic ordering temperatures. These unusual phonon anomalies indicate that the spin-orbit coupling in Mott-insulating iridates is not sufficiently strong to quench the orbital dynamics in the paramagnetic state.

  15. Expert Meeting Report: Cladding Attachment Over Exterior Insulation

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P. [Building Science Corporation, Somerville, MA (United States)

    2013-10-01

    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. The location of the insulation to 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 thestructure, as well as other commonly associated improvements such as increased air tightness and improved water management (Hutcheon 1964, Lstiburek 2007). The intent of the meeting was to review the current state of industry knowledge regarding cladding attachment over exterior insulation with a specific focus on: 1. Gravity load resistance, 2. Wind load resistance. The presentations explorethese topics from an engineering design, laboratory testing, field monitoring, as well as practical construction perspective. By bringing various groups together (who have been conduction research or have experience in this area), a more holistic review of the design limits and current code language proposals can be completed and additional gaps identified. The results of which will help informdesign standards and criteria.

  16. Expert Meeting Report: Cladding Attachment Over Exterior Insulation (BSC Report)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-10-01

    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. The location of the insulation to 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 air tightness and improved water management (Hutcheon 1964, Lstiburek 2007). The intent of the meeting was to review the current state of industry knowledge regarding cladding attachment over exterior insulation with a specific focus on: 1. Gravity load resistance, 2. Wind load resistance. The presentations explore these topics from an engineering design, laboratory testing, field monitoring, as well as practical construction perspective. By bringing various groups together (who have been conduction research or have experience in this area), a more holistic review of the design limits and current code language proposals can be completed and additional gaps identified. The results of which will help inform design standards and criteria.

  17. Development of electrical insulator coatings for fusion power applications

    International Nuclear Information System (INIS)

    Park, J.H.; Domenico, T.; Dragel, G.; Clark, R.

    1995-01-01

    In the design of liquid-metal cooling systems for fusion blanket applications, the corrosion resistance of structural materials and the magnetohydrodynamic (MHD) force and its subsequent influence on thermal hydraulics and corrosion are major concerns. The objective of this study was to develop stable corrosion-resistant electrical insulator coatings at the liquid-metal-structural-material interface, with emphasis on electrically insulating coatings that prevent adverse MHD-generated currents from passing through the structural walls. Vanadium and V-base alloys (V-Ti or V-Ti-Cr) are leading candidate materials for structural applications in fusion reactors. When the system is cooled by liquid metals, insulator coatings are required on piping surfaces in contact with the coolant. Various intermetallic films were produced on V, V-5Ti, and V-20Ti, V-5Cr-5Ti, and V-15Cr-5Ti, and Ti, and on types 304 and 316 stainless steel. The intermetallic layers were developed by exposure of the materials to liquid Li containing 3-5at.% dissolved metallic solute (e.g. Al, Be, Mg, Si, Ca, Pt, and Cr) at temperatures of 416-880 C. Subsequently, electrical insulator coatings were produced by reaction of the reactive layers with dissolved N in liquid Li or by air oxidation under controlled conditions at 600-1000 C. These reactions converted the intermetallic layers to electrically insulating oxide-nitride or oxynitride layers. This coating method is applicable to reactor components. The liquid metal can be used over and over because only the solutes are consumed within the liquid metal. The technique can be applied to various shapes (e.g. inside or outside of tubes, complex geometrical shapes) because the coating is formed by liquid-phase reaction. This paper discusses initial results on the nature of the coatings (composition, thickness, adhesion, surface coverage) and their in situ electrical resistivity characteristics in liquid Li at high temperatures. (orig.)

  18. Effects of cryogenic reactor irradiation on organic insulators

    International Nuclear Information System (INIS)

    Kato, Teruo

    1995-01-01

    Insulators for the superconducting magnets of fusion reactor are classified as electrical and thermal insulators for which tough organic materials will be used. When the magnet is exposed by fast neutrons and gamma-rays from plasma in a fusion reactor, the fusion reactor systems will cause fatal damage by the degradation of insulators. Therefore, it is necessary to select materials resistant irradiation damage for use as insulators. Electrical and mechanical tests were carried out at 4.2 K without warmup after the reactor irradiation at 5 K. The effects of reactor irradiation at the dose of 10 7 Gy on epoxy resins (bisphenol-A), G-10 CR, VL-E 200 and G-11 CR caused large decreases in mechanical strength. Polyetheretherketone (PEEK), polyimide and phenol novolac resins, which were used to laminate reinforced plastics with glass-cloth against irradiation, showed good resistance. Effects of cryogenic reactor irradiation on several organic materials and epoxy laminate-reinforced plastics with glass-cloth and Kevlar-cloth were also discussed. (author)

  19. Electrical insulation and conduction coating for fusion experimental devices

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, Masanori; Tsujimura, Seiji; Toyoda, Masahiko; Inoue, Masahiko [Mitsubishi Heavy Industries, Ltd., Yokohama (Japan); Abe, Tetsuya; Murakami, Yoshio [Japan Atomic Energy Research Inst., Naka (Japan)

    1996-01-01

    The development of electrical insulation and conduction coating methods that can be applied to large components of fusion experimental devices has been investigated. A thermal spraying method is used to coat the insulation or conduction materials on the structural components because of its applicability for large surfaces. The insulation material chosen was Al{sub 2}O{sub 3}, while Cr{sub 3}C{sub 2}-NiCr and WC-NiCr were chosen as conduction materials. These materials were coated on stainless steel substrates to examine the basic characteristics of the coated layers, such as their adhesive strength to the substrate, thermal shock resistance, electrical resistance, dielectric breakdown voltage, and thermal conductivity. It was found that they have sufficient electrical insulation and conduction properties, respectively. In addition, the sliding tests of the coated layers showed adequate frictional properties. The spraying method was tested on a 100- x 1000-mm surface and found to be applicable for large surfaces of experimental fusion devices. 9 refs., 6 figs., 15 tabs.

  20. Electrical insulation and conduction coating for fusion experimental devices

    International Nuclear Information System (INIS)

    Onozuka, Masanori; Tsujimura, Seiji; Toyoda, Masahiko; Inoue, Masahiko; Abe, Tetsuya; Murakami, Yoshio

    1996-01-01

    The development of electrical insulation and conduction coating methods that can be applied to large components of fusion experimental devices has been investigated. A thermal spraying method is used to coat the insulation or conduction materials on the structural components because of its applicability for large surfaces. The insulation material chosen was Al 2 O 3 , while Cr 3 C 2 -NiCr and WC-NiCr were chosen as conduction materials. These materials were coated on stainless steel substrates to examine the basic characteristics of the coated layers, such as their adhesive strength to the substrate, thermal shock resistance, electrical resistance, dielectric breakdown voltage, and thermal conductivity. It was found that they have sufficient electrical insulation and conduction properties, respectively. In addition, the sliding tests of the coated layers showed adequate frictional properties. The spraying method was tested on a 100- x 1000-mm surface and found to be applicable for large surfaces of experimental fusion devices. 9 refs., 6 figs., 15 tabs

  1. An investigation on rapeseed oil as potential insulating liquid

    Science.gov (United States)

    Katim, N. I. A.; Nasir, M. S. M.; Ishak, M. T.; Hamid, M. H. A.

    2018-02-01

    Insulation oils are a vital part in power transformers. Insulation oil is not only work as electrical insulation but also as a coolant inside the transformer. Due to the increasing tight regulations on the environment and safety in recent years, vegetable oils are being considered for insulation oils in power transformer. This paper presents two conditions of Rapeseed Oil (RO), which are as received (new) and dried (dry) under difference uniform field electrodes configuration (mushroom-to-mushroom and sphere-to-sphere) with gap distance at 2.5 mm as recommended by the international standards. A comparative study of AC breakdown voltage, dissipation factor (tan δ), and resistivity under variation of temperature were investigated. The experimental works were done according to the IEC 60156 and IEC 60247 standards. The results indicated that the breakdown voltages of both condition are comparable to mineral oil. The dielectric constant and resistivity of two conditions are decreased along with the increasing temperature. However, the dissipation factor properties rose up along with the temperature. The Weibull distribution was used to determine the withstand voltages at 1% and 50% for RO in two probabilities conditions.

  2. Electrical insulators for the theta-pinch fusion reactor

    International Nuclear Information System (INIS)

    Clinard, F.W. Jr.

    1976-01-01

    The five major applications for electrical insulators in the Reference Theta Pinch Reactor are as follows: (1) first-wall insulator, (2) blanket intersegment insulator, (3) graphite encapsulating insulator, (4) implosion coil insulator, and (5) compression coil insulator. Insulator design proposals and some preliminary test results are given for each application

  3. Metal–insulator transition in Ni-doped Na0.75CoO2: Insights from ...

    Indian Academy of Sciences (India)

    resistivity on lowering the temperature, with the metal-to-insulator transition temperature. (TMIT) increasing with the Ni ... The Ni-doped sample is seen to change over from a metallic to insulating behaviour at ~175 K. The ..... neutron diffraction to look for structural changes, viz., changes in bond lengths and site occupancies ...

  4. Stability of alternating current discharges between water drops on insulation surfaces

    International Nuclear Information System (INIS)

    Rowland, S M; Lin, F C

    2006-01-01

    Discharges between water drops are important in the ageing of hydrophobic outdoor insulators. They may also be important in the processes leading up to flashover of these insulators in high pollution conditions. This paper considers discharges between drops when a limited alternating current is available, as experienced by an ageing insulator in service. A phenomenon is identified in which the length of a discharge between two drops is reduced through a particular type of distortion of the drops. This is visually characterized as a liquid protrusion from each of a pair of water drops along the insulator surface. This process is distinct from vibration of the drops, general distortion of their shape and the very fast emission of jet streams seen in very high fields. The process depends upon the discharge current, the resistivity of the moisture and the hydrophobicity of the insulation surface

  5. Impact of moisture content in AAC on its heat insulation properties

    Science.gov (United States)

    Rubene, S.; Vilnitis, M.

    2017-10-01

    One of the most popular trends in construction industry is sustainable construction. Therefore, application of construction materials with high insulation characteristics has significantly increased during the past decade. Requirements for application of construction materials with high insulation parameters are required not only by means of energy saving and idea of sustainable construction but also by legislative requirements. Autoclaved aerated concrete (AAC) is a load bearing construction material, which has high heat insulation parameters. However, if the AAC masonry construction has high moisture content the heat insulation properties of the material decrease significantly. This fact lead to the necessity for the on-site control of moisture content in AAC in order to avoid inconsistency between the designed and actual thermal resistivity values of external delimiting constructions. Research of the impact of moisture content in AAC on its heat insulation properties has been presented in this paper.

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

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1994-01-01

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

  7. Wood moisture monitoring during log house thermal insulation mounting

    Directory of Open Access Journals (Sweden)

    Pavla Kotásková

    2011-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Smajo Sulejmanovic

    2014-11-01

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

  9. Heat resistant/radiation resistant cable and incore structure test device for FBR type reactor

    International Nuclear Information System (INIS)

    Tanimoto, Hajime; Shiono, Takeo; Sato, Yoshimi; Ito, Kazumi; Sudo, Shigeaki; Saito, Shin-ichi; Mitsui, Hisayasu.

    1995-01-01

    A heat resistant/radiation resistant coaxial cable of the present invention comprises an insulation layer, an outer conductor and a protection cover in this order on an inner conductor, in which the insulation layer comprises thermoplastic polyimide. In the same manner, a heat resistant/radiation resistant power cable has an insulation layer comprising thermoplastic polyimide on a conductor, and is provided with a protection cover comprising braid of alamide fibers at the outer circumference of the insulation layer. An incore structure test device for an FBR type reactor comprises the heat resistant/radiation resistant coaxial cable and/or the power cable. The thermoplastic polyimide can be extrusion molded, and has excellent radiation resistant by the extrusion, as well as has high dielectric withstand voltage, good flexibility and electric characteristics at high temperature. The incore structure test device for the FBR type reactor of the present invention comprising such a cable has excellent reliability and durability. (T.M.)

  10. Effects of pressure on doped Kondo insulators

    International Nuclear Information System (INIS)

    Lee, Chengchung; Xu, Wang

    1999-08-01

    The effects of pressure on the doped Kondo insulators (KI) are studied in the framework of the slave-boson mean-field theory under the coherent potential approximation (CPA). A unified picture for both electron-type KI and hole-type KI is presented. The density of states of the f-electrons under the applied pressures and its variation with the concentration of the Kondo holes are calculated self-consistently. The specific heat coefficient, the zero-temperature magnetic susceptibility as well as the low temperature electric resistivity of the doped KI under various pressures are obtained. The two contrasting pressure-dependent effects observed in the doped KI systems can be naturally explained within a microscopic model. (author)

  11. Positron Annihilation in Insulating Materials

    International Nuclear Information System (INIS)

    Asoka-Kumar, P; Sterne, PA

    2002-01-01

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

  12. Floquet topological insulators for sound

    Science.gov (United States)

    Fleury, Romain; Khanikaev, Alexander B.; Alù, Andrea

    2016-06-01

    The unique conduction properties of condensed matter systems with topological order have recently inspired a quest for the similar effects in classical wave phenomena. Acoustic topological insulators, in particular, hold the promise to revolutionize our ability to control sound, allowing for large isolation in the bulk and broadband one-way transport along their edges, with topological immunity against structural defects and disorder. So far, these fascinating properties have been obtained relying on moving media, which may introduce noise and absorption losses, hindering the practical potential of topological acoustics. Here we overcome these limitations by modulating in time the acoustic properties of a lattice of resonators, introducing the concept of acoustic Floquet topological insulators. We show that acoustic waves provide a fertile ground to apply the anomalous physics of Floquet topological insulators, and demonstrate their relevance for a wide range of acoustic applications, including broadband acoustic isolation and topologically protected, nonreciprocal acoustic emitters.

  13. Fermi surfaces in Kondo insulators

    Science.gov (United States)

    Liu, Hsu; Hartstein, Máté; Wallace, Gregory J.; Davies, Alexander J.; Ciomaga Hatnean, Monica; Johannes, Michelle D.; Shitsevalova, Natalya; Balakrishnan, Geetha; Sebastian, Suchitra E.

    2018-04-01

    We report magnetic quantum oscillations measured using torque magnetisation in the Kondo insulator YbB12 and discuss the potential origin of the underlying Fermi surface. Observed quantum oscillations as well as complementary quantities such as a finite linear specific heat capacity in YbB12 exhibit similarities with the Kondo insulator SmB6, yet also crucial differences. Small heavy Fermi sections are observed in YbB12 with similarities to the neighbouring heavy fermion semimetallic Fermi surface, in contrast to large light Fermi surface sections in SmB6 which are more similar to the conduction electron Fermi surface. A rich spectrum of theoretical models is suggested to explain the origin across different Kondo insulating families of a bulk Fermi surface potentially from novel itinerant quasiparticles that couple to magnetic fields, yet do not couple to weak DC electric fields.

  14. Topological insulators and topological superconductors

    CERN Document Server

    Bernevig, Andrei B

    2013-01-01

    This graduate-level textbook is the first pedagogical synthesis of the field of topological insulators and superconductors, one of the most exciting areas of research in condensed matter physics. Presenting the latest developments, while providing all the calculations necessary for a self-contained and complete description of the discipline, it is ideal for graduate students and researchers preparing to work in this area, and it will be an essential reference both within and outside the classroom. The book begins with simple concepts such as Berry phases, Dirac fermions, Hall conductance and its link to topology, and the Hofstadter problem of lattice electrons in a magnetic field. It moves on to explain topological phases of matter such as Chern insulators, two- and three-dimensional topological insulators, and Majorana p-wave wires. Additionally, the book covers zero modes on vortices in topological superconductors, time-reversal topological superconductors, and topological responses/field theory and topolo...

  15. Heat Transfer Measurement and Modeling in Rigid High-Temperature Reusable Surface Insulation Tiles

    Science.gov (United States)

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

    2011-01-01

    Heat transfer in rigid reusable surface insulations was investigated. Steady-state thermal conductivity measurements in a vacuum were used to determine the combined contribution of radiation and solid conduction components of heat transfer. Thermal conductivity measurements at higher pressures were then used to estimate the effective insulation characteristic length for gas conduction modeling. The thermal conductivity of the insulation can then be estimated at any temperature and pressure in any gaseous media. The methodology was validated by comparing estimated thermal conductivities with published data on a rigid high-temperature silica reusable surface insulation tile. The methodology was also applied to the alumina enhanced thermal barrier tiles. Thermal contact resistance for thermal conductivity measurements on rigid tiles was also investigated. A technique was developed to effectively eliminate thermal contact resistance on the rigid tile s cold-side surface for the thermal conductivity measurements.

  16. A study on influence of borax to polyester insulators

    OpenAIRE

    ERSOY, Aysel; KUNTMAN, Ayten

    2014-01-01

    In this study the effect of borax on polyester insulators is investigated by evaluating the tracking and erosion resistance using the inclined plane test. The test procedure follows the ASTM D2303 standard. During the test, 50 Hz current was acquired from the ground electrode allowing a sampling rate of 48000 samples per second. The effect of borax concentration on the glass transition and the degradation temperature is studied by employing differential scanning calorimetry (DSC) an...

  17. Topological insulators fundamentals and perspectives

    CERN Document Server

    Ortmann, Frank; Valenzuela, Sergio O

    2015-01-01

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

  18. Electric fields and electrical insulation

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson

    2002-01-01

    The adoption of a field-theoretical approach to problems arising in the framework of electrical insulation is discussed with reference to six main topics, which have been addressed over the last 30 years. These include uniform field electrodes, Green's differential equation, electrode surface...... roughness, induced charge, electrostatic probes, and partial discharge transients, together with several follow-on aspects. Each topic is introduced and thereafter the progress achieved through the use of a field-theoretical approach is reviewed. Because the topics cover a wide spectrum of conditions......, it is amply demonstrated that such an approach can lead to significant progress in many areas of electrical insulation....

  19. A real-time insulation detection method for battery packs used in electric vehicles

    Science.gov (United States)

    Tian, Jiaqiang; Wang, Yujie; Yang, Duo; Zhang, Xu; Chen, Zonghai

    2018-05-01

    Due to the energy crisis and environmental pollution, electric vehicles have become more and more popular. Compared to traditional fuel vehicles, the electric vehicles are integrated with more high-voltage components, which have potential security risks of insulation. The insulation resistance between the chassis and the direct current bus of the battery pack is easily affected by factors such as temperature, humidity and vibration. In order to ensure the safe and reliable operation of the electric vehicles, it is necessary to detect the insulation resistance of the battery pack. This paper proposes an insulation detection scheme based on low-frequency signal injection method. Considering the insulation detector which can be easily affected by noises, the algorithm based on Kalman filter is proposed. Moreover, the battery pack is always in the states of charging and discharging during driving, which will lead to frequent changes in the voltage of the battery pack and affect the estimation accuracy of insulation detector. Therefore the recursive least squares algorithm is adopted to solve the problem that the detection results of insulation detector mutate with the voltage of the battery pack. The performance of the proposed method is verified by dynamic and static experiments.

  20. Structure, Mechanism, and Application of Vacuum Insulation Panels in Chinese Buildings

    Directory of Open Access Journals (Sweden)

    Changhai Peng

    2016-01-01

    Full Text Available Thermal insulation is one of the most used approaches to reduce energy consumption in buildings. Vacuum insulation panels (VIPs are new thermal insulation materials that have been used in the domestic and overseas market in the last 20 years. Due to the vacuum thermal insulation technology of these new materials, their thermal conductivity can be as low as 0.004 W/(m·K at the center of panels. In addition, VIPs that are composites with inorganic core and an envelope out of commonly three metallized PET layers and a PE sealing layer can provide B class fire resistance (their core materials are not flammable and are classified as A1. Compared with other conventional thermal insulation materials, the thermal insulation and fire resistance performances form the foundation of VIP’s applications in the construction industry. The structure and thermal insulation mechanism of VIP and their application potential and problems in Chinese buildings are described in detail.

  1. CCD and IR array controllers

    Science.gov (United States)

    Leach, Robert W.; Low, Frank J.

    2000-08-01

    A family of controllers has bene developed that is powerful and flexible enough to operate a wide range of CCD and IR focal plane arrays in a variety of ground-based applications. These include fast readout of small CCD and IR arrays for adaptive optics applications, slow readout of large CCD and IR mosaics, and single CCD and IR array operation at low background/low noise regimes as well as high background/high speed regimes. The CCD and IR controllers have a common digital core based on user- programmable digital signal processors that are used to generate the array clocking and signal processing signals customized for each application. A fiber optic link passes image data and commands to VME or PCI interface boards resident in a host computer to the controller. CCD signal processing is done with a dual slope integrator operating at speeds of up to one Megapixel per second per channel. Signal processing of IR arrays is done either with a dual channel video processor or a four channel video processor that has built-in image memory and a coadder to 32-bit precision for operating high background arrays. Recent developments underway include the implementation of a fast fiber optic data link operating at a speed of 12.5 Megapixels per second for fast image transfer from the controller to the host computer, and supporting image acquisition software and device drivers for the PCI interface board for the Sun Solaris, Linux and Windows 2000 operating systems.

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

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund; Dreau, Jerome Le

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

  3. Polymer Reinforced, Non-Brittle, Light-Weight Cryogenic Insulation for Reduced Life Cycle Costs, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — InnoSense LLC (ISL) proposes to fabricate a composite aerogel foam. This material is designed to be impact resistant, non-brittle, non-water-retaining and insulating...

  4. High pressure metallization of Mott Insulators: Magnetic, structural and electronic properties

    International Nuclear Information System (INIS)

    Pasternak, M.P.; Hearne, G.; Sterer, E.; Taylor, R.D.; Jeanloz, R.

    1993-01-01

    High pressure studies of the insulator-metal transition in the (TM)I 2 (TM = V, Fe, Co and Ni) compounds are described. Those divalent transition-metal iodides are structurally isomorphous and classified as Mott Insulators. Resistivity, X-ray diffraction and Moessbauer Spectroscopy were employed to investigate the electronic, structural, and magnetic properties as a function of pressure both on the highly correlated and on the metallic regimes

  5. Characterization of the Quantized Hall Insulator Phase in the Quantum Critical Regime

    OpenAIRE

    Song, Juntao; Prodan, Emil

    2013-01-01

    The conductivity $\\sigma$ and resistivity $\\rho$ tensors of the disordered Hofstadter model are mapped as functions of Fermi energy $E_F$ and temperature $T$ in the quantum critical regime of the plateau-insulator transition (PIT). The finite-size errors are eliminated by using the non-commutative Kubo-formula. The results reproduce all the key experimental characteristics of this transition in Integer Quantum Hall (IQHE) systems. In particular, the Quantized Hall Insulator (QHI) phase is det...

  6. OGTT results in obese adolescents with normal HOMA-IR values.

    Science.gov (United States)

    Sahin, Nursel Muratoglu; Kinik, Sibel Tulgar; Tekindal, Mustafa Agah

    2013-01-01

    To investigate insulin resistance (IR) with OGTT in obese adolescents who have normal fasting insulin and homeostasis model assessment for insulin resistance (HOMA-IR). A total of 97 obese adolescents who had values of HOMA-IR IR using an insulin peak of ≥150 μU/mL (1041.8 pmol/L) and/or ≥75 μU/mL (520.9 pmol/L) 120 min after glucose charge and the sum of insulin levels >2083.5 pmol/L (300 μU/mL) in OGTT. IR risk factors were defined as family history of diabetes mellitus, acanthosis nigricans (AN), and hepatic steatosis. IR was detected in 61 (62.9%) patients. The IR group had significantly more frequent AN (p=0.0001). As the number of risk factors increased, the frequency of IR also increased (p=0.01). We advise to perform OGTT in obese adolescents with normal HOMA-IR, if they have risk factors for IR.

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

    Directory of Open Access Journals (Sweden)

    M. Talafi Noghani

    2014-02-01

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

  8. Complex studies of mockups of electric insulators of cryoresistive coils of the T-15 device electromagnet system

    International Nuclear Information System (INIS)

    Aksenov, O.E.; Gringof, V.G.; Il'in, G.V.; Lapenas, A.A.; Stepanov, A.N.; Ulmanis, U.A.

    1982-01-01

    The test results are presented for multilayer electrical insulation of coils in the T-15 thermonuclear device electromagnet system. The insulation is made ion the base of polyimide tape with adhesive coating. In the 77-93 K range the tape insulating strength is 35 MV/m, the dielectric loss tangent is less than 10 -5 , dielectric permeability is 2.5, volume resistivity is more than 10 5 Ohmxcm. The insulation has been tested for radiation effects in the IRT-2000 nuclear reactor. Different batches of insulation mockups 0.7 mm thick have been irradiated up to the integral fast neutron flux within the 10 16 -5x10 18 neutr./cm 2 range (E >= 0.1 MeV), (J=10 11 -10 12 neutr./cm 2 xs) at the corresponding temperature between 390 and 420 K. The given data on insulating strength point to a high radiation resistance of the multilayer polyimide insulation. To make sure finally that the developed insulation system meets the requirements of the operating conditions for thermonuclear device electromagnet system coils the device has been tested for operational life. On the basis of the test results a conclusion can be made that at the present development stage the multilayer polyimide insulation based on the adhesive tape meets to the utmost degree the requirements corresponding to the complicated operating conditions of the T-15 thermonuclear devices

  9. Electrical insulation for large multiaxis superconducting magnets

    International Nuclear Information System (INIS)

    Harvey, A.R.; Rinde, J.A.

    1975-01-01

    The selection of interturn and interlayer insulation for superconducting magnets is discussed. The magnet problems of the Baseball II device are described. Manufacture of the insulation and radiation damage are mentioned. A planned experimental program is outlined

  10. Emerging Trends in Topological Insulators and Topological ...

    Indian Academy of Sciences (India)

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

  11. Vacuum-insulated catalytic converter

    Science.gov (United States)

    Benson, David K.

    2001-01-01

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

  12. On effective holographic Mott insulators

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-12-20

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

  13. On effective holographic Mott insulators

    International Nuclear Information System (INIS)

    Baggioli, Matteo; Pujolàs, Oriol

    2016-01-01

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

  14. Thermal insulation of fuel elements

    International Nuclear Information System (INIS)

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

    1978-01-01

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

  15. Forming Refractory Insulation On Copper Wire

    Science.gov (United States)

    Setlock, J.; Roberts, G.

    1995-01-01

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

  16. Optimization design for SST-1 Tokamak insulators

    International Nuclear Information System (INIS)

    Zhang Yuanbin; Pan Wanjiang

    2012-01-01

    With the help of ANSYS FEA technique, high voltage and cryogenic proper- ties of the SST-1 Tokamak insulators were obtained, and the structure of the insulators was designed and modified by taking into account the simulation results. The simulation results indicate that the optimization structure has better high voltage insulating property and cryogenic mechanics property, and also can fulfill the qualification criteria of the SST-1 Tokamak insulators. (authors)

  17. Polyimide Foams Offer Superior Insulation

    Science.gov (United States)

    2012-01-01

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

  18. Insulator applications in a Tokamak reactor

    International Nuclear Information System (INIS)

    Leger, D.

    1986-06-01

    Insulators, among which insulators ceramics, have great potential applications in fusion reactors. They will be used for all plasma-facing components as protection and, magnetic fusion devices being subject to large electrical currents flowing in any parts of the device, for their electrical insulating properties

  19. Hippocampal insulin resistance and cognitive dysfunction

    NARCIS (Netherlands)

    Biessels, Geert Jan; Reagan, Lawrence P.

    2015-01-01

    Clinical studies suggest a link between type 2 diabetes mellitus (T2DM) and insulin resistance (IR) and cognitive dysfunction, but there are significant gaps in our knowledge of the mechanisms underlying this relationship. Animal models of IR help to bridge these gaps and point to hippocampal IR as

  20. High voltage diagnostics on electrical insulation of supersonducting magnets

    International Nuclear Information System (INIS)

    Irmisch, M.

    1995-12-01

    The high voltage (HV) performance of superconducting magnets of large dimensions, e.g. as needed in fusion reactors, is a challange in the field of high voltage technology, i.e. especially in the field of cryogenic high voltage components and with respect to questions of HV insulation diagnostics at low temperature. By using the development of POLO - a superconducting prototype coil of a tokamak poloidal field coil - as an example, this work deals with special problems of how to get use of conventional HV test techniques for diagnostics under special cryogenic boundary conditions. As a first approach to gain experience in the field of phase resolved partial discharge (PRPD) measurements during operation of a superconductive coil, the POLO coil was subject to several high voltage tests. Compared with DC insulation resistance measurements and capacitive impulse voltage discharges to the coil, the AC PD measurements have been the only way to observe special characteristics of the electrical insulation with respect to the cooling down of the coil from 300 K to 4.2 K. The PRPD measurement technique thereby has proofed as a suitable diagnostic tool. This work can serve as basic data to be comparable within further projects of electrical insulation diagnostics at cryogenic temperatures. (orig.)

  1. Harnessing the metal-insulator transition for tunable metamaterials

    Science.gov (United States)

    Charipar, Nicholas A.; Charipar, Kristin M.; Kim, Heungsoo; Bingham, Nicholas S.; Suess, Ryan J.; Mathews, Scott A.; Auyeung, Raymond C. Y.; Piqué, Alberto

    2017-08-01

    The control of light-matter interaction through the use of subwavelength structures known as metamaterials has facilitated the ability to control electromagnetic radiation in ways not previously achievable. A plethora of passive metamaterials as well as examples of active or tunable metamaterials have been realized in recent years. However, the development of tunable metamaterials is still met with challenges due to lack of materials choices. To this end, materials that exhibit a metal-insulator transition are being explored as the active element for future metamaterials because of their characteristic abrupt change in electrical conductivity across their phase transition. The fast switching times (▵t < 100 fs) and a change in resistivity of four orders or more make vanadium dioxide (VO2) an ideal candidate for active metamaterials. It is known that the properties associated with thin film metal-insulator transition materials are strongly dependent on the growth conditions. For this work, we have studied how growth conditions (such as gas partial pressure) influence the metalinsulator transition in VO2 thin films made by pulsed laser deposition. In addition, strain engineering during the growth process has been investigated as a method to tune the metal-insulator transition temperature. Examples of both the optical and electrical transient dynamics facilitating the metal-insulator transition will be presented together with specific examples of thin film metamaterial devices.

  2. Experimental bandstructure of the 5 d transition metal oxide IrO2

    Science.gov (United States)

    Kawasaki, Jason; Nie, Yuefeng; Uchida, Masaki; Schlom, Darrell; Shen, Kyle

    2015-03-01

    In the 5 d iridium oxides the close energy scales of spin-orbit coupling and electron-electron correlations lead to emergent quantum phenomena. Much research has focused on the ternary iridium oxides, e.g. the Ruddlesden-Poppers An + 1BnO3 n + 1 , which exhibit behavior from metal to antiferromagnetic insulator ground states, share common features with the cuprates, and may host a number of topological phases. The binary rutile IrO2 is another important 5 d oxide, which has technological importance for spintronics due to its large spin Hall effect and also applications in catalysis. IrO2 is expected to share similar physics as its perovskite-based cousins; however, due to bond-length distortions of the IrO6 octahedra in the rutile structure, the extent of similarities remains an open question. Here we use angle-resolved photoemission spectroscopy to perform momentum-resolved measurements of the electronic structure of IrO2 . IrO2 thin films were grown by molecular beam epitaxy on TiO2 (110) substrates using an Ir e-beam source and distilled ozone. Films were subsequently transferred through ultrahigh vacuum to a connected ARPES system. Combined with first-principles calculations we explore the interplay of spin-orbit coupling and correlations in IrO2 .

  3. The Associations Between Increasing Degrees of HOMA-IR and Measurements of Adiposity Among Euglycemic U.S. Adults.

    Science.gov (United States)

    Boyer, William R; Johnson, Tammie M; Fitzhugh, Eugene C; Richardson, Michael R; Churilla, James R

    2016-03-01

    The purpose of this study was to examine the associations between increasing degrees of insulin resistance (using the homeostatic model assessment of insulin resistance [HOMA-IR]) and two measures of adiposity in a nationally representative sample of euglycemic U.S. adults. Sample included adult participants (≥ 20 years of age) [N = 1586 (body mass index, BMI model), N = 1577 (waist circumference, WC model)] from the 1999-2004 National Health and Nutrition Examination Survey (NHANES). HOMA-IR was categorized into quartiles. BMI and WC were examined continuously as the dependent variables. Following adjustment for covariates, those with HOMA-IR values in the second, third, and fourth quartiles had significantly higher BMIs (P HOMA-IR (P HOMA-IR and BMI (R(2) = 0.4171, P HOMA-IR and WC (R(2) = 0.4826, P HOMA-IR value is associated with higher BMI and WC values in euglycemic subjects.

  4. Influence of deposition conditions on the nature of epitaxial SrIrO3 on STO (001)

    Science.gov (United States)

    Bhat, Shwetha G.; Sebastian, Nirmal K.; Kumar, P. S. Anil

    2018-05-01

    SrIrO3 (SIO) is one of the materials known to exhibit a high spin-orbit coupling with correlated semi-metallic ground state, along with the topological states, as proven in recent times. In this regard, the SIO thin films grown by us on SrTiO3 (001) at certain deposition conditions, exhibit a low temperature magneto-transport behavior which is analogous to the materials with topological states. Further, we have explored various deposition conditions of SIO such as partial pressure of O2 and different temperatures of growth for different thickness of SIO. In addition, from the electrical transport properties, SIO thin films found to exhibit semi-metallic nature with either insulating-like or a crossover from metal-like to insulating-like behavior based on the conditions chosen for the growth. Moreover, the magneto-transport data of various SIO thin films are found to be obeying the usual B2 (Lorentzian) behavior in majority of the cases. At the same time, we have also observed the weak-localization and weak-antilocalization effects; along with a linear magneto-resistance at low temperature ranges. Thus, from our extensive measurements, it becomes clear that SIO thin films can exhibit wide varieties of magneto-transport properties based on the deposition conditions. Plethora of interesting properties exhibited by the highly spin-orbit coupled SIO epitaxial thin films at lower temperatures in the presence of magnetic field makes the material to be promising for the future applications in the field of spintronics.

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  6. Dielectric and Insulating Technology 2005 : Reviews & Forecasts

    Science.gov (United States)

    Okamoto, Tatsuki

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

  7. Dielectric and Insulating Technology 2006 : Review & Forecast

    Science.gov (United States)

    Okamoto, Tatsuki

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

  8. High sensitivity thermal sensors on insulating diamond

    Energy Technology Data Exchange (ETDEWEB)

    Job, R. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Denisenko, A.V. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Zaitsev, A.M. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Melnikov, A.A. [Belarussian State Univ., Minsk (Belarus). HEII and FD; Werner, M. [VDI/VDE-IT, Teltow (Germany); Fahrner, W.R. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices

    1996-12-15

    Diamond is a promising material to develop sensors for applications in harsh environments. To increase the sensitivity of diamond temperature sensors the effect of thermionic hole emission (TE) over an energetic barrier formed in the interface between highly boron-doped p-type and intrinsic insulating diamond areas has been suggested. To study the TE of holes a p-i-p diode has been fabricated and analyzed by electrical measurements in the temperature range between 300 K and 700 K. The experimental results have been compared with numerical simulations of its electrical characteristics. Based on a model of the thermionic emission of carriers into an insulator it has been suggested that the temperature sensitivity of the p-i-p diode on diamond is strongly affected by the re-emission of holes from a group of donor-like traps located at a level of 0.7-1.0 eV above the valence band. The mechanism of thermal activation of the current includes a spatial redistribution of the potential, which results in the TE regime from a decrease of the immobilized charge of the ionized traps within the i-zone of the diode and the correspondent lowering of the forward biased barrier. The characteristics of the p-i-p diode were studied with regard to temperature sensor applications. The temperature coefficient of resistance (TCR=-0.05 K{sup -1}) for temperatures above 600 K is about four times larger than the maximal attainable TCR for conventional boron-doped diamond resistors. (orig.)

  9. Data in support of FSH induction of IRS-2 in human granulosa cells: Mapping the transcription factor binding sites in human IRS-2 promoter

    Directory of Open Access Journals (Sweden)

    Surleen Kaur

    2016-03-01

    Full Text Available Insulin receptor substrate-2 (IRS-2 plays critical role in the regulation of various metabolic processes by insulin and IGF-1. The defects in its expression and/or function are linked to diseases like polycystic ovary syndrome (PCOS, insulin resistance and cancer. To predict the transcription factors (TFs responsible for the regulation of human IRS-2 gene expression, the transcription factor binding sites (TFBS and the corresponding TFs were investigated by analysis of IRS-2 promoter sequence using MatInspector Genomatix software (Cartharius et al., 2005 [1]. The ibid data is part of author׳s publication (Anjali et al., 2015 [2] that explains Follicle stimulating hormone (FSH mediated IRS-2 promoter activation in human granulosa cells and its importance in the pathophysiology of PCOS. Further analysis was carried out for binary interactions of TF regulatory genes in IRS-2 network using Cytoscape software tool and R-code. In this manuscript, we describe the methodology used for the identification of TFBSs in human IRS-2 promoter region and provide details on experimental procedures, analysis method, validation of data and also the raw files. The purpose of this article is to provide the data on all TFBSs in the promoter region of human IRS-2 gene as it has the potential for prediction of the regulation of IRS-2 gene in normal or diseased cells from patients with metabolic disorders and cancer. Keywords: IRS-2, TFBS, FSH, SP1, ChIP

  10. Quantum fluctuations in insulating ferroelectrics

    International Nuclear Information System (INIS)

    Riseborough, Peter S.

    2010-01-01

    Graphical abstract: It has been proposed that in a ferroelectric insulator, an applied magnetic field may couple the transverse phonon modes and produce left and right circularly polarized phonon modes which are no longer degenerate. We quantize the theory and examine the effects of quantal fluctuations. In particular, we show that the zero point fluctuations result in a large diamagnetic contribution to the magnetic susceptibility. - Abstract: It has been proposed that in a ferroelectric insulator, an applied magnetic field may couple the transverse phonon modes and produce left and right circularly polarized phonon modes which are no longer degenerate. We quantize the theory and examine the effects of quantal fluctuations. In particular, we show that the zero-point fluctuations result in a large diamagnetic contribution to the magnetic susceptibility.

  11. Multilayer Insulation Ascent Venting Model

    Science.gov (United States)

    Tramel, R. W.; Sutherlin, S. G.; Johnson, W. L.

    2017-01-01

    The thermal and venting transient experienced by tank-applied multilayer insulation (MLI) in the Earth-to-orbit environment is very dynamic and not well characterized. This new predictive code is a first principles-based engineering model which tracks the time history of the mass and temperature (internal energy) of the gas in each MLI layer. A continuum-based model is used for early portions of the trajectory while a kinetic theory-based model is used for the later portions of the trajectory, and the models are blended based on a reference mean free path. This new capability should improve understanding of the Earth-to-orbit transient and enable better insulation system designs for in-space cryogenic propellant systems.

  12. Chiral topological insulator of magnons

    Science.gov (United States)

    Li, Bo; Kovalev, Alexey A.

    2018-05-01

    We propose a magnon realization of 3D topological insulator in the AIII (chiral symmetry) topological class. The topological magnon gap opens due to the presence of Dzyaloshinskii-Moriya interactions. The existence of the topological invariant is established by calculating the bulk winding number of the system. Within our model, the surface magnon Dirac cone is protected by the sublattice chiral symmetry. By analyzing the magnon surface modes, we confirm that the backscattering is prohibited. By weakly breaking the chiral symmetry, we observe the magnon Hall response on the surface due to opening of the gap. Finally, we show that by changing certain parameters, the system can be tuned between the chiral topological insulator, three-dimensional magnon anomalous Hall, and Weyl magnon phases.

  13. Magnetically insulated transmission line oscillator

    Science.gov (United States)

    Bacon, L.D.; Ballard, W.P.; Clark, M.C.; Marder, B.M.

    1987-05-19

    A magnetically insulated transmission line oscillator employs self-generated magnetic fields to generate microwave energy. An anode of the oscillator includes slow-wave structures which are formed of a plurality of thin conductive vanes defining cavities therebetween, and a gap is formed between the anode and a cathode of the oscillator. In response to a pulsed voltage applied to the anode and cathode, self-generated magnetic fields are produced in a cross-field orientation with respect to the orientation of the electric field between the anode and the cathode. The cross-field magnetic fields insulate the flow of electrons in the gap and confine the flow of electrons within the gap. 11 figs.

  14. Insulation assembly for electric machine

    Science.gov (United States)

    Rhoads, Frederick W.; Titmuss, David F.; Parish, Harold; Campbell, John D.

    2013-10-15

    An insulation assembly is provided that includes a generally annularly-shaped main body and at least two spaced-apart fingers extending radially inwards from the main body. The spaced-apart fingers define a gap between the fingers. A slot liner may be inserted within the gap. The main body may include a plurality of circumferentially distributed segments. Each one of the plurality of segments may be operatively connected to another of the plurality of segments to form the continuous main body. The slot liner may be formed as a single extruded piece defining a plurality of cavities. A plurality of conductors (extendable from the stator assembly) may be axially inserted within a respective one of the plurality of cavities. The insulation assembly electrically isolates the conductors in the electric motor from the stator stack and from other conductors.

  15. Insulin resistance in polycystic ovary syndrome

    OpenAIRE

    Hutchison, Samantha Kate

    2017-01-01

    Polycystic ovary syndrome (PCOS) affects 8-18% of women, presenting a major public health and economic burden. Women with PCOS have insulin resistance (IR) independent of obesity. IR has an integral aetiological role in the reproductive and metabolic consequences of PCOS including obesity, type 2 diabetes (diabetes) and cardiovascular risk factors. Excess weight exacerbates IR and increases PCOS severity. PCOS combined with obesity presents a useful model to study IR before confounding hyperg...

  16. Relationship between HOMA-IR and serum vitamin D in Chinese children and adolescents.

    Science.gov (United States)

    Wang, Lingli; Wang, Huiyan; Wen, Huaikai; Tao, Hongqun; Zhao, Xiaowei

    2016-07-01

    The objective of this study was to examine the cross-sectional relationship between homeostasis model assessment for insulin resistance (HOMA-IR) and serum 25-hydroxyvitamin D (25-OHD) level in Chinese children and adolescents. Anthropometric indices, lipid metabolic profile, and serum levels of glucose, insulin and 25-OHD were determined among 278 healthy prepubertal and pubertal, normal and overweight/obese children and adolescents aged 8-18 years between March 2014 and February 2015. HOMA-IR was significantly different across vitamin D statuses (pHOMA-IR negatively correlated with serum 25-OHD level for all subjects (R2=0.148, pHOMA-IR and BMI and serum 25-OHD level (R2=0.654, pHOMA-IR. Our findings supported that lower vitamin D status is strongly associated with worse HOMA-IR.

  17. Secondary electron emission from insulators

    International Nuclear Information System (INIS)

    Kanaya, K.; Ono, S.; Ishigaki, F.

    1978-01-01

    The high yield of secondary electron emission from insulators due to electron bombardment may be the result of an increase of the depth of escape. The free-electron scattering theory is applied to the high energy of primary beams, but cannot be applied to the low energy of secondary escaping beams because of the large energy gap of the insulators. The plasmon loss with the valence electron is considered when the secondary electrons escape. Based on the energy retardation power formula of the penetration and energy loss of an electron probe into solid targets, secondary electron emissions from insulators are calculated from the assumptions that the distribution of the secondary electrons due to both incident and back-scattered electrons within the target is isotropic and that it follows the absorption law of the Lenard type. The universal yield-energy curve of the secondary electron emission, which is deduced as a function of three parameters such as ionisation potential, valence electron and the back-scattered coefficient in addition to the free-electron density effect, is found to be in good agreement with the experimental results. (author)

  18. Broadly tunable picosecond ir source

    International Nuclear Information System (INIS)

    Campillo, A.J.; Hyer, R.C.; Shapiro, S.L.

    1979-01-01

    A completely grating tuned (1.9 to 2.4 μm) picosecond traveling wave IR generator capable of controlled spectral bandwidth operation down to the Fourier Transform limit is reported. Subsequent down conversion in CdSe extends tuning to 10 to 20 μm

  19. Prevalence of the insulin resistance syndrome in obesity

    OpenAIRE

    Viner, R; Segal, T; Lichtarowicz-Kryn..., E; Hindmarsh, P

    2005-01-01

    Aims: To assess prevalence of the insulin resistance syndrome (IRS: obesity, abnormal glucose homoeostasis, dyslipidaemia, and hypertension) in obese UK children and adolescents of different ethnicities and to assess whether fasting data is sufficient to identify IRS in childhood obesity.

  20. Coexistence of metallic and insulating channels in compressed YbB6

    Science.gov (United States)

    Ying, Jianjun; Tang, Lingyun; Chen, Fei; Chen, Xianhui; Struzhkin, Viktor V.

    2018-03-01

    It remains controversial whether compressed YbB6 material is a topological insulator or a Kondo topological insulator. We performed high-pressure transport, x-ray diffraction (XRD), x-ray absorption spectroscopy, and Raman-scattering measurements on YbB6 samples in search for its topological Kondo phase. Both high-pressure powder XRD and Raman measurements show no trace of structural phase transitions in YbB6 up to 50 GPa. The nonmagnetic Yb2 + gradually change to magnetic Yb3 + above 18 GPa concomitantly with the increase in resistivity. However, the transition to the insulating state occurs only around 30 GPa, accompanied by the increase in the shear stress, and anomalies in the pressure dependence of the Raman T2 g mode and in the B atomic position. The resistivity at high pressures can be described by a model taking into account coexisting insulating and metallic channels with the activation energy for the insulating channel about 30 meV. We argue that YbB6 may become a topological Kondo insulator at high pressures above 35 GPa.

  1. Superconductor-insulator transitions in 2D: the experimental situation

    International Nuclear Information System (INIS)

    Markovic, N.; Christiansen, C.; Mack, A.; Goldman, A.M.

    2000-01-01

    Superconductor-insulator (SI) transitions in ultrathin films have attracted significant attention over the last decade because of the possibility that they are quantum phase transitions. Magnetic field, film thickness, or carrier concentration can be used as control parameters. The bosonic pictures of these transitions proposed some years ago are only in qualitative agreement with experiment. In particular, the critical resistance appears not to be universal, and there are variations in the values of critical exponents. It has been concluded that in real films fermionic degrees of freedom must be taken into account. There are also indications that the phase diagram may include a significant metallic phase separating the superconducting and insulating phases, and that the transition may have a significant percolative aspect. The experimental situation will be broadly reviewed with attention paid to issues relating to materials and measurements. (orig.)

  2. Alkoholio ir tabako pasiūlos ir paklausos teisinio reguliavimo raida Lietuvos Respublikoje: problemos ir sprendimai

    OpenAIRE

    Mockevičius, Arminas

    2014-01-01

    Viešosios teisės magistro studijų programos studento Armino Mockevičiaus buvo parašytas magistro baigiamasis darbas „Alkoholio ir tabako pasiūlos ir paklausos teisinio reguliavimo raida Lietuvos Respublikoje: problemos ir sprendimai“. Šis darbas parašytas Vilniuje, 2014 metais, Mykolo Romerio universiteto Teisės fakulteto Konstitucinės ir administracinės teisės institute, vadovaujant dr. Gintautui Vilkeliui, apimtis 98 p. Darbo tikslas yra atskleisti alkoholio ir tabako pasiūlos ir paklau...

  3. MTF measurement of IR optics in different temperature ranges

    Science.gov (United States)

    Bai, Alexander; Duncker, Hannes; Dumitrescu, Eugen

    2017-10-01

    Infrared (IR) optical systems are at the core of many military, civilian and manufacturing applications and perform mission critical functions. To reliably fulfill the demanding requirements imposed on today's high performance IR optics, highly accurate, reproducible and fast lens testing is of crucial importance. Testing the optical performance within different temperature ranges becomes key in many military applications. Due to highly complex IR-Applications in the fields of aerospace, military and automotive industries, MTF Measurement under realistic environmental conditions become more and more relevant. A Modulation Transfer Function (MTF) test bench with an integrated thermal chamber allows measuring several sample sizes in a temperature range from -40 °C to +120°C. To reach reliable measurement results under these difficult conditions, a specially developed temperature stable design including an insulating vacuum are used. The main function of this instrument is the measurement of the MTF both on- and off-axis at up to +/-70° field angle, as well as measurement of effective focal length, flange focal length and distortion. The vertical configuration of the system guarantees a small overall footprint. By integrating a high-resolution IR camera with focal plane array (FPA) in the detection unit, time consuming measurement procedures such as scanning slit with liquid nitrogen cooled detectors can be avoided. The specified absolute accuracy of +/- 3% MTF is validated using internationally traceable reference optics. Together with a complete and intuitive software solution, this makes the instrument a turn-key device for today's state-of- the-art optical testing.

  4. [HOMA-IR in patients with chronic hepatitis C].

    Science.gov (United States)

    Botshorishvili, T; Vashakidze, E

    2012-02-01

    The aim of investigation was to study the frequency of IR in type of viral hepatitis C, correlation with the degree of hepatic lesion and liver cirrhosis. 130 patients were investigated: 20 with acute hepatitis C; 38 with chronic hepatitis C; 72 with cirrhosis: among them 10 with Stage A, 14 with Stage B and 48 with Stage C. Also we used 30 healthy people as the controls. The study demonstrates significant changes of insulin, glucose, HOMA-IR type of viral hepatitis C, correlation with the degree of hepatic lesion and liver cirrhosis. In patients with liver cirrhosis levels of HOMA-IR is higher than in patients with chronic hepatitis C. In patients with acute hepatitis C levels of HOMA-IR was normal as in the control group. The results showed that various types of chronic viral hepatitis C and stages of cirrhosis set to increase HOMA-IR versus the controls., which were the most prominent in cases of severe hepatic lesion, which indicates that insulin resistance is a frequent companion of CHC.

  5. Variability in HOMA-IR, lipoprotein profile and selected hormones in young active men.

    Science.gov (United States)

    Keska, Anna; Lutoslawska, Grazyna; Czajkowska, Anna; Tkaczyk, Joanna; Mazurek, Krzysztof

    2013-01-01

    Resistance to insulin actions is contributing to many metabolic disturbances. Such factors as age, sex, nutrition, body fat, and physical activity determine body insulin resistance. Present study attempted to asses insulin resistance and its metabolic effects with respect to energy intake in young, lean, and active men. A total of 87 men aged 18-23 participated in the study. Plasma levels of glucose, insulin, lipoproteins, cortisol, and TSH were determined. Insulin resistance was expressed as Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) and calculated using homeostatic model. The median value of HOMA-IR (1.344) was used to divide subjects into two groups. Men did not differ in anthropometric parameters, daily physical activity, and plasma TSH and cortisol levels. However, in men with higher HOMA-IR significantly lower daily energy intake was observed concomitantly with higher TG, TC, and HDL-C concentrations in plasma versus their counterparts with lower HOMA-IR. Exclusively in subjects with higher HOMA-IR significant and positive correlation was noted between HOMA-IR and TC and LDL-C. We concluded that despite a normal body weight and physical activity, a subset of young men displayed unfavorable changes in insulin sensitivity and lipid profile, probably due to insufficient energy intake.

  6. Effects of insulation on potted superconducting coils

    International Nuclear Information System (INIS)

    Zeller, A.F.; DeKamp, J.C.; Magsig, C.T.; Nolen, J.A.; McInturff, A.D.

    1989-01-01

    Test coils using identical wire but with either Formvar or Polyesterimid insulation were fabricated to determine the effects of insulation on training behavior. It was found that the type of insulation did not affect the training behavior. While considerable attention has been paid to epoxy formulations used for superconducting coils, little study has been devoted to the effects of the wire insulation on training behavior. If the insulation does not bind well with the epoxy, the wires will not be held securely in place, and training will be required to make the coil operate at its design limit. In fact, the coil may never reach its design current, showing considerable degredation. Conversely, if the epoxy-insulation reaction is to soften or weaken the insulation, then shorts and/or training may result. The authors have undertaken a study of the effects of the insulation on potted coils wet wound with Stycast 2850 FT epoxy. The wire was insulated with one of two insulting varnishes: Formvar (a polyvinyl formal resin) or Polyesterimid (a phenolic resin). Formvar is the standard insulation in the United States while Polyesterimid the European standard

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

    Science.gov (United States)

    Kobayashi, Koji; Akiyama, Yoko; Nishijima, Shigehiro

    2017-09-01

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

  8. Development of electrical insulation and conduction coating for fusion experimental devices

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, M. [Mitsubishi Heavy Industries Ltd., Yokohama (Japan); Tsujimura, S. [Mitsubishi Heavy Industries Ltd., Yokohama (Japan); Toyoda, M. [Mitsubishi Heavy Industries Ltd., Yokohama (Japan); Inoue, M. [Mitsubishi Heavy Industries Ltd., Yokohama (Japan); Abe, T. [Japan Atomic Energy Research Inst., Naka (Japan); Murakami, Y. [Japan Atomic Energy Research Inst., Naka (Japan)

    1995-12-31

    Development of electrical insulation and conduction methods that can be applied for large components have been investigated for future large fusion experimental devices. A thermal spraying method is employed to coat the insulation or conduction materials on the structural components. Al{sub 2}O{sub 3} has been selected as an insulation material, while Cr{sub 3}C{sub 2}-NiCr and WC-NiCr have been chosen as conduction materials. These materials were coated on stainless steel base plates to examine the basic characteristics of the coated layers, such as their adhesive strength to the base plate and electrical resistance. It was found that they have sufficient electrical insulation and conduction properties, respectively. In addition, the sliding tests of the coated layers showed sufficient frictional properties. The applicability of the spraying method was examined on a 100mm x 1000mm surface and found to be applicable for large surfaces in fusion experimental devices. (orig.).

  9. Development of electrical insulation and conduction coating for fusion experimental devices

    International Nuclear Information System (INIS)

    Onozuka, M.; Tsujimura, S.; Toyoda, M.; Inoue, M.; Abe, T.; Murakami, Y.

    1995-01-01

    Development of electrical insulation and conduction methods that can be applied for large components have been investigated for future large fusion experimental devices. A thermal spraying method is employed to coat the insulation or conduction materials on the structural components. Al 2 O 3 has been selected as an insulation material, while Cr 3 C 2 -NiCr and WC-NiCr have been chosen as conduction materials. These materials were coated on stainless steel base plates to examine the basic characteristics of the coated layers, such as their adhesive strength to the base plate and electrical resistance. It was found that they have sufficient electrical insulation and conduction properties, respectively. In addition, the sliding tests of the coated layers showed sufficient frictional properties. The applicability of the spraying method was examined on a 100mm x 1000mm surface and found to be applicable for large surfaces in fusion experimental devices. (orig.)

  10. Electrical-Based Diagnostic Techniques for Assessing Insulation Condition in Aged Transformers

    Directory of Open Access Journals (Sweden)

    Issouf Fofana

    2016-08-01

    Full Text Available The condition of the internal cellulosic paper and oil insulation are of concern for the performance of power transformers. Over the years, a number of methods have been developed to diagnose and monitor the degradation/aging of the transformer internal insulation system. Some of this degradation/aging can be assessed from electrical responses. Currently there are a variety of electrical-based diagnostic techniques available for insulation condition monitoring of power transformers. In most cases, the electrical signals being monitored are due to mechanical or electric changes caused by physical changes in resistivity, inductance or capacitance, moisture, contamination or aging by-products in the insulation. This paper presents a description of commonly used and modern electrical-based diagnostic techniques along with their interpretation schemes.

  11. Insulator-insulator and insulator-conductor transitions in the phase diagram of aluminium trichloride

    Directory of Open Access Journals (Sweden)

    Romina Ruberto

    2009-01-01

    Full Text Available We report a classical computer-simulation study of the phase diagram of AlCl3 in the pressure-temperature (p, T plane, showing (i that melting from a layered crystal structure occurs into a molecular liquid at low (p, T and into a dissociated ionic liquid at high (p, T, and (ii that a broad transition from a molecular insulator to an ionic conductor takes place in the liquid state.

  12. Locking of iridium magnetic moments to the correlated rotation of oxygen octahedra in Sr2IrO4 revealed by x-ray resonant scattering

    DEFF Research Database (Denmark)

    Boseggia, S.; Walker, H. C.; Vale, J.

    2013-01-01

    Sr2IrO4 is a prototype of the class of Mott insulators in the strong spin–orbit interaction (SOI) limit described by a Jeff = 1/2 ground state. In Sr2IrO4, the strong SOI is predicted to manifest itself in the locking of the canting of the magnetic moments to the correlated rotation by 11.8(1)° o...

  13. Insulation Progress since the Mid-1950s

    Science.gov (United States)

    Timmerhaus, K. D.

    Storage vessel and cryostat design for modern cryogenic systems has become rather routine as the result of the wide use of and application of cryogenic fluids. Such vessels for these fluids range in size from 1 L flasks used in the laboratory for liquid nitrogen to the more than 200,000 m3 double-walled tanks used for temporary storage of liquefied natural gas before being transported overseas to their final destination. These storage vessels for cryogenic fluids range in type from low-performance containers insulated with rigid foam or fibrous insulation to high-performance containers insulated with evacuated multilayer insulations. The overriding factors in the type of container selected normally are of economics and safety. This paper will consider various insulation concepts used in such cryogenic storage systems and will review the progress that has been made over the past 50 years in these insulation systems.

  14. Handleable shapes of thermal insulation material

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, J. T.

    1989-01-17

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

  15. Hydrogen storage in insulated pressure vessels

    Energy Technology Data Exchange (ETDEWEB)

    Aceves, S.M.; Garcia-Villazana, O. [Lawrence Livermore National Lab., CA (United States)

    1998-08-01

    Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen (LH{sub 2}) or ambient-temperature compressed hydrogen (CH{sub 2}). Insulated pressure vessels offer the advantages of liquid hydrogen tanks (low weight and volume), with reduced disadvantages (lower energy requirement for hydrogen liquefaction and reduced evaporative losses). This paper shows an evaluation of the applicability of the insulated pressure vessels for light-duty vehicles. The paper shows an evaluation of evaporative losses and insulation requirements and a description of the current analysis and experimental plans for testing insulated pressure vessels. The results show significant advantages to the use of insulated pressure vessels for light-duty vehicles.

  16. ASRM case insulation design and development

    Science.gov (United States)

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

    1992-10-01

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

  17. Efficacy of the sibutramine in the insulin resistance and glycaemic control of obese patients / Eficacia de la sibutramina en la resistencia insulínica y el control glucémico de pacientes obesos

    Directory of Open Access Journals (Sweden)

    Pereira LRL

    2005-12-01

    Full Text Available Objective: This paper compared the effects of the sibutramine and of the metformin in the patients' obesity bearers insulin resistance. Methods: They were appraised 16 subjects obese with IMC above 30 Kg/m2, during 6 months and divided in two groups. The patients, before they begin the study, they were submitted to an evaluation anthropometric, clinic and laboratorial. All the patients received an individualized alimentary plan, respecting the total energy expense daily. Results: At the end of the study, it was observed that the plasmatic concentrations of insulin suffered reduction of 12,1% (sibutramine and 20,7% (metformin, and the values of HOMA also suffered reduction of 11,2% and 23,5%, respectively in the group sibutramine and metformin. In compensation, the patients of the group sibutramine obtained more satisfactory results than the group metformin in the reduction of the corporal weight and in IMC.Conclusion: This study demonstrated that the sibutramine, when compared to the metformin, it presents good results in the patients' glycaemic control, mainly in the insulin values and HOMA. The sibutramine, when prescribed in a rational way, an important therapeutic tool can be considered in the control of the diabetes type 2 and others adjunct pathology, however it should always be used simultaneous with an agent antidiabetic in those patient ones.

  18. ON THE NEED TO INCREASE THE RELIABILITY OF LINEAR INSULATORS FOR DISTRIBUTION NETWORKS 10-20 KV

    Directory of Open Access Journals (Sweden)

    Yu. N. Shumilov

    2018-02-01

    Full Text Available Introduction. In Ukraine high voltage overhead distribution lines (OL of class 6 and 10 kV are the most extended. Their total length exceeds 280,000 km. More than 95% of the lines are made on line supports from reinforced concrete racks. On all poles of the overhead line, pin insulators are installed. According to the data of operation experience, up to 60-70% of single-phase earth (SPE faults due to «insulation» occurs on VL supports due to damage to line pin insulators, mainly during the thunderstorm period. Problem. Insufficient reliability of pin insulators leads to interruptions in power supply, accidents on the line, accidents in the area of reinforced concrete poles, where in the case of insulator damages, a long process of SPE occurs. Goal. The purpose of the work is to select the design and develop requirements for new linear insulators of 10-20 kV overhead lines that provide high resistance to lightning overvoltages with direct and inductive effects of lightning. Methodology. The research methodology consists in analyzing operational experience, calculating insulator parameters and laboratory tests. Results. Using statistical data on lightning parameters and data on mechanical loads on insulators, the main dimensions of line post insulators have been determined that will ensure their reliable operation under conditions of intense thunderstorm activity and extreme ice and wind loads. Conclusions. The main technical requirements for line post insulators for 10-20 kV distribution lines were formulated. On the 10 kV OL located in areas with increased thunderstorm activity it is recommended to use line post insulators instead of pin-type ones. On the OL-20 kV it is recommended to use only line post insulators. The use of high-lightning-resistant line post insulators on OL-10-20 kV will significantly increase the electrical safety and reliability of power supply to consumers. Increased by 2-3 times the cost of line post insulators in

  19. Oferta ir akceptas vartojimo sutartyse

    OpenAIRE

    Ežerskytė, Ramunė

    2011-01-01

    Sutarčiai sudaryti paprastai reikia, kad viena šalis pasiūlytų sudaryti sutartį (oferta), o kita šalis sutiktų su pasiūlymu (akceptas). Sutarčių įvairovėje išskiriamos vartojimo sutartys, kurios dėl silpnesnės šalies apsaugos principo įgyvendinimo pasižymi tam tikrais ypatumais. Vartojimo sutarčių sudarymas pateikiant ofertą ir akceptą yra šio magistro baigiamojo darbo objektas. Magistro baigiamąjį darbą sudaro trys dalys. Pirmojoje darbo dalyje analizuojama vartojimo sutarties sąvoka ir spec...

  20. Insulin Resistance

    DEFF Research Database (Denmark)

    Jensen, Benjamin Anderschou Holbech

    Insulin resistance (IR) is escalating with alarming pace and is no longer restricted to westernized countries. As a forerunner for some of the most serious threats to human health including metabolic syndrome, cardiovascular diseases, and type 2-diabetes, the need for new treatment modalities...... interventions. We further show that improving the inflammatory toning, using fish oil as fat source, protects mice against diet induced obesity and -inflammation while preserving insulin sensitivity, even in the absence of free fatty acid receptor 4. Conversely, HFD-induced intestinal dysbiosis is associated...

  1. Processing of insulators and semiconductors

    Science.gov (United States)

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

    2015-06-16

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

  2. Characterization of Microporous Insulation, Microsil

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-06-15

    Microsil microporous insulation has been characterized by Lawrence Livermore National Laboratory for possible use in structural and thermal applications in the DPP-1 design. Qualitative test results have provided mechanical behavioral characteristics for DPP-1 design studies and focused on the material behavioral response to being crushed, cyclically loaded, and subjected to vibration for a confined material with an interference fit or a radial gap. Quantitative test results have provided data to support the DPP-1 FEA model analysis and verification and were used to determine mechanical property values for the material under a compression load. The test results are documented within this report.

  3. Method of manufacturing a thermally insulating body

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-10-11

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

  4. Dielectric and Insulating Technology 2004 : Review & Forecast

    Science.gov (United States)

    Okamoto, Tatsuki

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

  5. Process insulation. Isolation thermique des equipements

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

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

  6. Low Permeability Polyimide Insulation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Resodyn Technologies proposes a new technology that enables the application of polyimide based cryogenic insulation with low hydrogen permeability. This effort...

  7. Development of large high-voltage pressure insulators for the Princeton TFTR [Tokamak Fusion Test Reactor] flexible transmission lines

    International Nuclear Information System (INIS)

    Scalise, D.T.; Fong, E.; Haughian, J.; Prechter, R.

    1986-10-01

    Specially formulated insulator materials with improved strength and high-voltage properties were developed and used for critical components of the flexible transmission lines to the TFTR neutral beam ion sources. These critical components are plates which support central conductors as they exit the high-voltage power supply and enter the ion source enclosure. Each plate acts both as a high-voltage insulator and as a pressure barrier to the SF 6 insulating gas. The original plate was made of commercial glass-epoxy laminate which limited the plate voltage capacity. The newly developed insulator is made of specially-formulated cycloalphatic Di-epoxide whose isotropic properties exhibit increased arc resistance. It is cast in one piece with skirts which greatly increase the breakdown voltage. This paper discusses the design, fabrication and testing of the new insulator

  8. Climate Prediction Center IR 4km Dataset

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CPC IR 4km dataset was created from all available individual geostationary satellite data which have been merged to form nearly seamless global (60N-60S) IR...

  9. IR emission and electrical conductivity of Nd/Nb-codoped TiO{sub x} (1.5 < x < 2) thin films grown by pulsed-laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tchiffo-Tameko, C.; Cachoncinlle, C. [GREMI, UMR 7344 CNRS-Université Orléans, 45067 Orléans Cedex 2 (France); Perriere, J. [Sorbonne Universités, UPMC Université Paris 06, UMR 7588, INSP, 75005 Paris (France); CNRS, UMR 7588, INSP, 75005 Paris (France); Nistor, M. [NILPRP, L 22 P.O. Box MG-36, 77125 Bucharest-Magurele (Romania); Petit, A.; Aubry, O. [GREMI, UMR 7344 CNRS-Université Orléans, 45067 Orléans Cedex 2 (France); Pérez Casero, R. [Departamento de Física Aplicada, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Millon, E., E-mail: eric.millon@univ-orleans.fr [GREMI, UMR 7344 CNRS-Université Orléans, 45067 Orléans Cedex 2 (France)

    2016-12-15

    Highlights: • Nd/Nb-codoped TiO{sub 2} PLD films are electrically insulating and transparent in the UV visible NIR spectral domain. • Nd/Nb-codoped oxygen deficient TiO{sub x} (x ≈ 1.5) films are conductive and absorbent. • IR emission of Nd{sup 3+} in codoped TiO{sub x} films is quenched due to oxygen deficiency. • High Nb-doping rate decreases the IR emission of Nd{sup 3+} in Nd/Nb-codoped TiO{sub 2} films. - Abstract: The effect of the co-doping with Nd and Nb on electrical and optical properties of TiO{sub x} films is reported. The role of oxygen vacancies on the physical properties is also evidenced. The films are grown by pulsed-laser deposition onto (001) sapphire and (100) silicon substrates. The substrate temperature was fixed at 700 °C. To obtain either stoichiometric (TiO{sub 2}) or highly oxygen deficient (TiO{sub x} with x < 1.6) thin films, the oxygen partial pressure was adjusted at 10{sup −1} and 10{sup −6} mbar, respectively. 1%Nd-1%Nb, 1%Nd-5%Nb and 5%Nd-1%Nb co-doped TiO{sub 2} were used as bulk ceramic target. Composition, structural and morphological properties of films determined by Rutherford backscattering spectroscopy, X-ray diffraction and scanning electron microscopy, are correlated to their optical (UV–vis transmission and photoluminescence) and electrical properties (resistivity at room temperature). The most intense Nd{sup 3+} emission in the IR domain is obtained for stoichiometric films. Codoping Nd-TiO{sub x} films by Nb{sup 5+} ions is found to decrease the photoluminescence efficiency. The oxygen pressure during the growth allows to tune the optical and electrical properties: insulating and highly transparent (80% in the visible range) Nd/Nb codoped TiO{sub 2} films are obtained at high oxygen pressure, while conductive and absorbent films are grown under low oxygen pressure (10{sup −6} mbar).

  10. Radioluminescence dating: the IR emission of feldspar

    International Nuclear Information System (INIS)

    Schilles, Thomas.; Habermann, Jan

    2000-01-01

    A new luminescence reader for radioluminescence (RL) measurements is presented. The system allows detection of RL emissions in the near infrared region (IR). Basic bleaching properties of the IR-RL emission of feldspars are investigated. Sunlight-bleaching experiments as a test for sensitivity changes are presented. IR-bleaching experiments were carried out to obtain information about the underlying physical processes of the IR-RL emission

  11. Resistive foil edge grading for accelerator and other high voltage structures

    Science.gov (United States)

    Caporaso, George J.; Sampayan, Stephen F.; Sanders, David M.

    2014-06-10

    In a structure or device having a pair of electrical conductors separated by an insulator across which a voltage is placed, resistive layers are formed around the conductors to force the electric potential within the insulator to distribute more uniformly so as to decrease or eliminate electric field enhancement at the conductor edges. This is done by utilizing the properties of resistive layers to allow the voltage on the electrode to diffuse outwards, reducing the field stress at the conductor edge. Preferably, the resistive layer has a tapered resistivity, with a lower resistivity adjacent to the conductor and a higher resistivity away from the conductor. Generally, a resistive path across the insulator is provided, preferably by providing a resistive region in the bulk of the insulator, with the resistive layer extending over the resistive region.

  12. Lateral topological crystalline insulator heterostructure

    Science.gov (United States)

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

    2017-06-01

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

  13. Thermal insulation properties of walls

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2014-05-01

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

  14. APPL1 potentiates insulin sensitivity by facilitating the binding of IRS1/2 to the insulin receptor.

    Science.gov (United States)

    Ryu, Jiyoon; Galan, Amanda K; Xin, Xiaoban; Dong, Feng; Abdul-Ghani, Muhammad A; Zhou, Lijun; Wang, Changhua; Li, Cuiling; Holmes, Bekke M; Sloane, Lauren B; Austad, Steven N; Guo, Shaodong; Musi, Nicolas; DeFronzo, Ralph A; Deng, Chuxia; White, Morris F; Liu, Feng; Dong, Lily Q

    2014-05-22

    Binding of insulin receptor substrate proteins 1 and 2 (IRS1/2) to the insulin receptor (IR) is essential for the regulation of insulin sensitivity and energy homeostasis. However, the mechanism of IRS1/2 recruitment to the IR remains elusive. Here, we identify adaptor protein APPL1 as a critical molecule that promotes IRS1/2-IR interaction. APPL1 forms a complex with IRS1/2 under basal conditions, and this complex is then recruited to the IR in response to insulin or adiponectin stimulation. The interaction between APPL1 and IR depends on insulin- or adiponectin-stimulated APPL1 phosphorylation, which is greatly reduced in insulin target tissues in obese mice. appl1 deletion in mice consistently leads to systemic insulin resistance and a significant reduction in insulin-stimulated IRS1/2, but not IR, tyrosine phosphorylation, indicating that APPL1 sensitizes insulin signaling by acting at a site downstream of the IR. Our study uncovers a mechanism regulating insulin signaling and crosstalk between the insulin and adiponectin pathways. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Isolated Gramicidin Peptides Probed by IR Spectroscopy

    NARCIS (Netherlands)

    Rijs, A. M.; Kabelac, M.; Abo-Riziq, A.; Hobza, P.; de Vries, M. S.

    2011-01-01

    We report double-resonant IR/UV ion-dip spectroscopy of neutral gramicidin peptides in the gas phase. The IR spectra of gramicidin A and C, recorded in both the 1000 cm(-1) to 1800 cm(-1) and the 2700 to 3750 cm(-1) region, allow structural analysis. By studying this broad IR range, various local

  16. Quantum oscillations in insulators with neutral Fermi surfaces

    Science.gov (United States)

    Sodemann, Inti; Chowdhury, Debanjan; Senthil, T.

    2018-02-01

    We develop a theory of quantum oscillations in insulators with an emergent Fermi sea of neutral fermions minimally coupled to an emergent U(1 ) gauge field. As pointed out by Motrunich [Phys. Rev. B 73, 155115 (2006), 10.1103/PhysRevB.73.155115], in the presence of a physical magnetic field the emergent magnetic field develops a nonzero value leading to Landau quantization for the neutral fermions. We focus on the magnetic field and temperature dependence of the analog of the de Haas-van Alphen effect in two and three dimensions. At temperatures above the effective cyclotron energy, the magnetization oscillations behave similarly to those of an ordinary metal, albeit in a field of a strength that differs from the physical magnetic field. At low temperatures, the oscillations evolve into a series of phase transitions. We provide analytical expressions for the amplitude and period of the oscillations in both of these regimes and simple extrapolations that capture well their crossover. We also describe oscillations in the electrical resistivity of these systems that are expected to be superimposed with the activated temperature behavior characteristic of their insulating nature and discuss suitable experimental conditions for the observation of these effects in mixed-valence insulators and triangular lattice organic materials.

  17. Fully developed magnetohydrodynamic flows in rectangular ducts with insulating walls

    International Nuclear Information System (INIS)

    Molokov, S.; Kernforschungszentrum Karlsruhe GmbH; Shishko, A.

    1993-10-01

    In the first part the effect of magnetic field inclination on the flow structure and the pressure drop is considered. The duct walls are insulating. An asymptotic solution to the problem at high Hartmann numbers is obtained. The results show that for a square duct the increase of the pressure gradient due to the field inclination is negligible (less than 10% for any angle). For blanket relevant values of inclination of up to 10 the deviation of the velocity profile from the slug profile is insignificant. The second part studies the flow in a duct with insulating walls parallel to the magnetic field, while the Hartmann walls are covered by an insulating coating. A new type of the boundary condition is derived, which takes into account finite coating resistance. The effect of the latter on the flow characteristics is studied. An exact solution to the problem is obtained and several approximate formulas for the pressure drop at high Hartmann numbers are presented. (orig./HP) [de

  18. Infrared (IR) photon-sensitive spectromicroscopy in a cryogenic environment

    Science.gov (United States)

    Pereverzev, Sergey

    2016-06-14

    A system designed to suppress thermal radiation background and to allow IR single-photon sensitive spectromicroscopy of small samples by using both absorption, reflection, and emission/luminescence measurements. The system in one embodiment includes: a light source; a plurality of cold mirrors configured to direct light along a beam path; a cold or warm sample holder in the beam path; windows of sample holder (or whole sample holder) are transparent in a spectral region of interest, so they do not emit thermal radiation in the same spectral region of interest; a cold monochromator or other cold spectral device configured to direct a selected fraction of light onto a cold detector; a system of cold apertures and shields positioned along the beam path to prevent unwanted thermal radiation from arriving at the cold monochromator and/or the detector; a plurality of optical, IR and microwave filters positioned along the beam path and configured to adjust a spectral composition of light incident upon the sample under investigation and/or on the detector; a refrigerator configured to maintain the detector at a temperature below 1.0K; and an enclosure configured to: thermally insulate the light source, the plurality of mirrors, the sample holder, the cold monochromator and the refrigerator.

  19. Metal–insulator crossover in high c cuprates: A gauge field ...

    Indian Academy of Sciences (India)

    A metal–insulator crossover appears in the experimental data for in-plane resistivity of underdoped cuprates and a range of superconducting cuprates in the presence of a strong magnetic field suppressing superconductivity. We propose an explanation for this phenomenon based on a gauge field theory approach to the t-J ...

  20. Damping and scattering of electromagnetic waves by small ferrite spheres suspended in an insulator

    Science.gov (United States)

    Englert, Gerald W.

    1992-01-01

    The intentional degradation of electromagnetic waves by their penetration into a media comprised of somewhat sparsely distributed energy absorbing ferrite spheres suspended in an electrical insulator is investigated. Results are presented in terms of generalized parameters involving wave length and sphere size, sphere resistivity, permeability, and spacing; their influence on dissipation of wave power by eddy currents, magnetic hysteresis, and scattering is shown.

  1. Insulin-induced translocation of IR to the nucleus in insulin responsive cells requires a nuclear translocation sequence.

    Science.gov (United States)

    Kesten, Dov; Horovitz-Fried, Miriam; Brutman-Barazani, Tamar; Sampson, Sanford R

    2018-04-01

    Insulin binding to its cell surface receptor (IR) activates a cascade of events leading to its biological effects. The Insulin-IR complex is rapidly internalized and then is either recycled back to the plasma membrane or sent to lysosomes for degradation. Although most of the receptor is recycled or degraded, a small amount may escape this pathway and migrate to the nucleus of the cell where it might be important in promulgation of receptor signals. In this study we explored the mechanism by which insulin induces IR translocation to the cell nucleus. Experiments were performed cultured L6 myoblasts, AML liver cells and 3T3-L1 adipocytes. Insulin treatment induced a rapid increase in nuclear IR protein levels within 2 to 5 min. Treatment with WGA, an inhibitor of nuclear import, reduced insulin-induced increases nuclear IR protein; IR was, however, translocated to a perinuclear location. Bioinformatics tools predicted a potential nuclear localization sequence (NLS) on IR. Immunofluorescence staining showed that a point mutation on the predicted NLS blocked insulin-induced IR nuclear translocation. In addition, blockade of nuclear IR activation in isolated nuclei by an IR blocking antibody abrogated insulin-induced increases in IR tyrosine phosphorylation and nuclear PKCδ levels. Furthermore, over expression of mutated IR reduced insulin-induced glucose uptake and PKB phosphorylation. When added to isolated nuclei, insulin induced IR phosphorylation but had no effect on nuclear IR protein levels. These results raise questions regarding the possible role of nuclear IR in IR signaling and insulin resistance. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Topological Insulators and Superconductors for Innovative Devices

    Science.gov (United States)

    2015-03-20

    Final 3. DATES COVERED (From - To) 20120321 - 20150320 4. TITLE AND SUBTITLE Topological insulators and superconductors for innovative...locking, which hold promise for various innovative devices. Similarly, topological superconductors are associated with exotic surface states, which...298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 Final Report Title: Topological Insulators and Superconductors for Innovative Devices

  3. Thermal insulation of high temperature reactors

    International Nuclear Information System (INIS)

    Cornille, Y.

    1975-01-01

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

  4. Quantitative analysis of thermal insulation coatings

    DEFF Research Database (Denmark)

    Kiil, Søren

    2014-01-01

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

  5. Study of thermal conductivity of multilayer insulation

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, D; Sundaram, S; Nath, G K; Sethuram, N P; Chandrasekharan, T; Varadarajan, T G [Heavy Water Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    This paper presents experimental determination of the apparent thermal conductivity of multilayer insulation for a cryogenic system. The variation of thermal conductivity with residual gas pressure is studied and the optimum vacuum for good insulating performance is determined. Evaporation loss technique for heat-inleak determination is employed. (author). 3 refs., 3 figs.

  6. Insulation systems for superconducting transmission cables

    DEFF Research Database (Denmark)

    Tønnesen, Ole

    1996-01-01

    the electrical insulation is placed outside both the superconducting tube and the cryostat. The superconducting tube is cooled by liquid nitrogen which is pumped through the hollow part of the tube.2) The cryogenic dielectric design, where the electrical insulation is placed inside the cryostat and thus is kept...

  7. Study of thermal conductivity of multilayer insulation

    International Nuclear Information System (INIS)

    Dutta, D.; Sundaram, S.; Nath, G.K.; Sethuram, N.P.; Chandrasekharan, T.; Varadarajan, T.G.

    1994-01-01

    This paper presents experimental determination of the apparent thermal conductivity of multilayer insulation for a cryogenic system. The variation of thermal conductivity with residual gas pressure is studied and the optimum vacuum for good insulating performance is determined. Evaporation loss technique for heat-inleak determination is employed. (author)

  8. Can positrons be guided by insulating capillaries?

    International Nuclear Information System (INIS)

    DuBois, R.D.; Toekesi, K.

    2011-01-01

    Complete text of publication follows. Investigations of guiding of few hundred eV antiparticles by macroscopic insulating capillaries have been described. Using subfemtoamp positron and electron beams, we demonstrated that a portion of the entering beams were transmitted and emerged in the direction of the capillary. We also demonstrated that the transmitted intensities decreased as the capillary tilt angle was increased (see Fig. 1). Both of these are indications of guiding. However, a comparison with transmitted photon data implies that the positron transmission may result from geometric factors associated with our diffuse beams and tapered capillary used in these studies. For electrons, the comparison indicates differences which could imply that even very low intensity beams can be guided. Measurements of the transmitted intensity as a function of charge entering the capillary were inconclusive as no major increases in the transmitted intensity were observed. 2D static simulations imply that our beam intensities, although extremely small with respect to previous guiding experiments, were capable of supplying sufficient charge for guiding to occur. Although not definitive, our study implies that sub-femtoamp beam intensities are sufficient to form charge patches and produce guiding. This may have been observed for electrons with the question remaining open for positrons. That guiding was not clearly seen may have been due to the capillary geometry used or it may indicate that although sufficient charge is being supplied, the surface and bulk resistivities of glass permit this charge to dissipate faster than it is formed. This aspect was not taken into consideration in our simulations but a crude estimate of the discharge rate implies that beam intensities on the order of pA, rather than fA as used here, may be required for guiding to occur in the capillaries used here. Additional studies are required to definitively answer the question as to whether antiparticles

  9. Aharonov–Bohm interference in topological insulator nanoribbons

    KAUST Repository

    Peng, Hailin; Lai, Keji; Kong, Desheng; Meister, Stefan; Chen, Yulin; Qi, Xiao-Liang; Zhang, Shou-Cheng; Shen, Zhi-Xun; Cui, Yi

    2009-01-01

    Topological insulators represent unusual phases of quantum matter with an insulating bulk gap and gapless edges or surface states. The two-dimensional topological insulator phase was predicted in HgTe quantum wells and confirmed by transport

  10. A cohort study of incident microalbuminuria in relation to HOMA-IR in Korean men.

    Science.gov (United States)

    Park, Sung Keun; Chun, Hyejin; Ryoo, Jae-Hong; Lee, Sang Wha; Lee, Hong Soo; Shim, Kyung Won; Cho, Choo Yon; Ryu, Dong-Ryeol; Ko, Taeg Su; Kim, Eugene; Park, Se-Jin; Park, Jai Hyung; Hong, Seok Jin; Hong, Hyun Pyo

    2015-06-15

    Despite the previous studies showing the relationship between microalbuminuria and insulin resistance, longitudinal effect of insulin resistance on development of microalbuminuria is not clearly identified in non-diabetic population. One thousand six hundred three non-diabetic Korean men without microalbuminuria in 2005 had been followed up for the development of microalbuminuria until 2010. Microalbuminuria was evaluated by urine-albumin creatinine ration, and insulin resistance was evaluated by homeostasis model assessment of insulin resistance (HOMA-IR). Cox proportional hazards model was used to estimate the risk for microalbuminuria according to the tertile of HOMA-IR. During 5465.8 person-y of average follow-up, microalbuminuria developed in 76 (4.7%) participants. Incidence of microalbuminuria increased in proportion to the level of HOMA-IR (tertile 1: 3.0%, tertile 2: 4.1%, tertile 3: 7.1%, PHOMA-IR was set as reference, hazard ratios and 95% confidence interval were 1.15 (0.56-2.35) and 2.07 (1.05-4.09) for those in the 2nd and 3rd tertiles of HOMA-IR, even after adjusting multiple covariates, respectively (P for linear trend=0.054). Increased insulin resistance was a predictor of microalbuminuria in Korean men. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Modeling of Dynamic Responses in Building Insulation

    Directory of Open Access Journals (Sweden)

    Anna Antonyová

    2015-10-01

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

  12. Topological Insulators Dirac Equation in Condensed Matters

    CERN Document Server

    Shen, Shun-Qing

    2012-01-01

    Topological insulators are insulating in the bulk, but process metallic states around its boundary owing to the topological origin of the band structure. The metallic edge or surface states are immune to weak disorder or impurities, and robust against the deformation of the system geometry. This book, Topological insulators, presents a unified description of topological insulators from one to three dimensions based on the modified Dirac equation. A series of solutions of the bound states near the boundary are derived, and the existing conditions of these solutions are described. Topological invariants and their applications to a variety of systems from one-dimensional polyacetalene, to two-dimensional quantum spin Hall effect and p-wave superconductors, and three-dimensional topological insulators and superconductors or superfluids are introduced, helping readers to better understand this fascinating new field. This book is intended for researchers and graduate students working in the field of topological in...

  13. Insulating Structural Ceramics Program, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Mark J.; Tandon, Raj; Ott, Eric; Hind, Abi Akar; Long, Mike; Jensen, Robert; Wheat, Leonard; Cusac, Dave; Lin, H. T.; Wereszczak, Andrew A.; Ferber, Mattison K.; Lee, Sun Kun; Yoon, Hyung K.; Moreti, James; Park, Paul; Rockwood, Jill; Boyer, Carrie; Ragle, Christie; Balmer-Millar, Marilou; Aardahl, Chris; Habeger, Craig; Rappe, Ken; Tran, Diana; Koshkarian, Kent; Readey, Michael

    2005-11-22

    New materials and corresponding manufacturing processes are likely candidates for diesel engine components as society and customers demand lower emission engines without sacrificing power and fuel efficiency. Strategies for improving thermal efficiency directly compete with methodologies for reducing emissions, and so the technical challenge becomes an optimization of controlling parameters to achieve both goals. Approaches being considered to increase overall thermal efficiency are to insulate certain diesel engine components in the combustion chamber, thereby increasing the brake mean effective pressure ratings (BMEP). Achieving higher BMEP rating by insulating the combustion chamber, in turn, requires advances in material technologies for engine components such as pistons, port liners, valves, and cylinder heads. A series of characterization tests were performed to establish the material properties of ceramic powder. Mechanical chacterizations were also obtained from the selected materials as a function of temperature utilizing ASTM standards: fast fracture strength, fatique resistance, corrosion resistance, thermal shock, and fracture toughness. All ceramic materials examined showed excellent wear properties and resistance to the corrosive diesel engine environments. The study concluded that the ceramics examined did not meet all of the cylinder head insert structural design requirements. Therefore we do not recommend at this time their use for this application. The potential for increased stresses and temperatures in the hot section of the diesel engine combined with the highly corrosive combustion products and residues has driven the need for expanded materials capability for hot section engine components. Corrosion and strength requirements necessitate the examination of more advanced high temperture alloys. Alloy developments and the understanding of processing, structure, and properties of supperalloy materials have been driven, in large part, by the gas

  14. Minimization of thermal insulation thickness taking into account condensation on external walls

    Directory of Open Access Journals (Sweden)

    Nurettin Yamankaradeniz

    2015-09-01

    Full Text Available Condensation occurs in the inner layers of construction materials at whatever point the partial pressure of water vapor diffuses and reaches its saturation pressure. Condensation, also called sweating, damages materials, reduces thermal resistance, and by increasing the total heat transfer coefficient, results in unwanted events such as increased heat loss. This study applied minimization of thermal insulation thickness with consideration given to condensation in the external walls. The calculations of heat and mass transfers in the structure elements are expressed in a graphical form. While there was an increase in the required thermal insulation thickness subsequent to an increase in the internal environment’s temperature, relative humidity, and the external environment’s relative humidity, the required thickness decreased with an increase in the external environment’s temperature. The amount of water vapor transferred varied with internal or external conditions and the thickness of the insulation. A change in the vapor diffusion resistance of the insulation material can increase the risk of condensation on the internal or external surfaces of the insulation.

  15. Plasma Deposited SiO2 for Planar Self-Aligned Gate Metal-Insulator-Semiconductor Field Effect Transistors on Semi-Insulating InP

    Science.gov (United States)

    Tabory, Charles N.; Young, Paul G.; Smith, Edwyn D.; Alterovitz, Samuel A.

    1994-01-01

    Metal-insulator-semiconductor (MIS) field effect transistors were fabricated on InP substrates using a planar self-aligned gate process. A 700-1000 A gate insulator of Si02 doped with phosphorus was deposited by a direct plasma enhanced chemical vapor deposition at 400 mTorr, 275 C, 5 W, and power density of 8.5 MW/sq cm. High frequency capacitance-voltage measurements were taken on MIS capacitors which have been subjected to a 700 C anneal and an interface state density of lxl0(exp 11)/eV/cq cm was found. Current-voltage measurements of the capacitors show a breakdown voltage of 107 V/cm and a insulator resistivity of 10(exp 14) omega cm. Transistors were fabricated on semi-insulating InP using a standard planar self-aligned gate process in which the gate insulator was subjected to an ion implantation activation anneal of 700 C. MIS field effect transistors gave a maximum extrinsic transconductance of 23 mS/mm for a gate length of 3 microns. The drain current drift saturated at 87.5% of the initial current, while reaching to within 1% of the saturated value after only 1x10(exp 3). This is the first reported viable planar InP self-aligned gate transistor process reported to date.

  16. Luminescence from metals and insulators

    International Nuclear Information System (INIS)

    Crawford, O.H.

    1985-01-01

    The term luminescence is normally applied to light emission that is not explainable by the mechanisms discussed by the other speakers in this meeting. Specifically, it is not transition radiation, surface plasmon radiation, or bremsstrahlung. One normally thinks of luminescence as arising from one-electron transitions within a medium. This talk consists of an overview of luminescence from condensed matter under irradiation by either energetic particles or photons. The author begins with organic molecules, where luminescence is best understood, and then discusses inorganic insulators and metals. Finally, the dependence of yield upon projectile species and velocity is discussed, and predictions are made concerning the relative effectiveness of electrons, protons, and hydrogen atoms in exciting luminescence

  17. Handbook of Thermal Insulation Applications.

    Science.gov (United States)

    1983-01-01

    Wiuppuoror *tIe beamsWiefag ln~ td ~oair ilmstool beams Plate 18. Metal Building Ceilings - A 18b: Fir* hataird rathge may limit the use of foam Insulation...RFCTANGUI.AR SOL TD A = 2(WxL+LxH+HxW) B V = WxLxH H L TRAPEZOID A 2 (A + B) x H A CONE A -n xRxS+ i xR 2 B V =( /3)x R2 x H TRIANGLE A BxH A- 2 CYLI NDER H 2...FABRICATIIG RECTANGULAR HEATING AND COOLING DUCTWORK. FIBERGLAS DUCT BOARD OWENS-CORNING FIBERGLAS CORP GLASS FIBER RIGID BOARD WITH ALUMINUM 4bD FOIL VAPOR

  18. Serum AMH levels and insulin resistance in women with PCOS.

    Science.gov (United States)

    Sahmay, Sezai; Aydogan Mathyk, Begum; Sofiyeva, Nigar; Atakul, Nil; Azemi, Aslı; Erel, Tamer

    2018-05-01

    To compare the serum AMH levels between women with and without insulin resistance (IR) in polycystic ovary syndrome (PCOS). 293 women with PCOS according to the Rotterdam criteria were enrolled into our study. Insulin resistance was diagnosed according to the Homeostatic model assessment insulin resistant (HOMA-IR) formula and the cut-off point was set to more than 2.5. Women were grouped according to the presence of insulin resistance (IR) (HOMA-IR ≥ 2.5). Serum AMH and other hormones were compared between the IR (+) and IR (-) groups. Additionally, AMH percentiles were (75) constructed; HOMA-IR and BMI values in women with/without IR were compared in different percentiles. Further, HOMA-IR, BMI and AMH values were measured across different PCOS phenotypes. The prevalence of IR was 45%. The prevalence of IR was 57% in women with BMI ≥ 25. Serum AMH levels were not significantly different among women with and without IR. Also, HOMA-IR values were not significant among different AMH percentiles. However, in each AMH percentile BMI were found to be higher in women with IR than in women without IR. The median HOMA-IR values were the highest in women with BMI ≥ 25 in both IR (+) and IR (-) groups. No significant difference was found among PCOS phenotypes in terms of HOMA-IR and BMI. Positive correlations were found between BMI, free testosterone and HOMA-IR. However, no correlation was found between AMH and HOMA-IR. The serum AMH levels between women with IR and without IR in PCOS were not significantly different. Also, we did not reveal a correlation between serum AMH levels and IR in women with PCOS. IR was not correlated with different PCOS phenotypes either. We found a positive correlation between BMI and IR. IR should be investigated in women with PCOS having a BMI ≥ 25, independent of their phenotype or AMH levels. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Interior insulation – Experimental investigation of hygrothermal conditions and damage evaluation of solid masonry façades in a listed building

    DEFF Research Database (Denmark)

    Odgaard, Tommy; Bjarløv, Søren Peter; Rode, Carsten

    2018-01-01

    Exterior walls in historic multi-storey buildings compared to walls in modern buildings have low thermal resistance, resulting in high energy loss and cold surfaces/floors in cold climates. When restrictions regarding alteration of the exterior appearance exist, interior insulation might be the o......Exterior walls in historic multi-storey buildings compared to walls in modern buildings have low thermal resistance, resulting in high energy loss and cold surfaces/floors in cold climates. When restrictions regarding alteration of the exterior appearance exist, interior insulation might...... be the only possibility to increase occupant comfort. This paper describes an investigation of the hygrothermal influence when applying 100 mm of diffusion open interior insulation to a historic multi-storey solid masonry spandrel. The dormitory room with the insulated spandrel had a normal indoor climate...... showed no risk of damage from the changed hygrothermal conditions when applying interior insulation to a solid masonry spandrel....

  20. Insulin Resistance of Puberty.

    Science.gov (United States)

    Kelsey, Megan M; Zeitler, Philip S

    2016-07-01

    Puberty is a time of considerable metabolic and hormonal change. Notably, puberty is associated with a marked decrease in insulin sensitivity, on par with that seen during pregnancy. In otherwise healthy youth, there is a nadir in insulin sensitivity in mid-puberty, and then it recovers at puberty completion. However, there is evidence that insulin resistance (IR) does not resolve in youth who are obese going into puberty and may result in increased cardiometabolic risk. Little is known about the underlying pathophysiology of IR in puberty, and how it might contribute to increased disease risk (e.g., type 2 diabetes). In this review, we have outlined what is known about the IR in puberty in terms of pattern, potential underlying mechanisms and other mediating factors. We also outline other potentially related metabolic changes that occur during puberty, and effects of underlying insulin resistant states (e.g., obesity) on pubertal changes in insulin sensitivity.

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

    International Nuclear Information System (INIS)

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

    1982-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-12-01

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

  3. Device characteristics of antenna-coupled metal-insulator-metal diodes (rectenna) using Al2O3, TiO2, and Cr2O3 as insulator layer for energy harvesting applications

    Science.gov (United States)

    Inac, Mesut; Shafique, Atia; Ozcan, Meric; Gurbuz, Yasar

    2015-09-01

    Antenna-coupled metal-insulator-metal devices are most potent candidate for future energy harvesting devices. The reason for that they are ultra-high speed devices that can rectify the electromagnetic radiation at high frequencies. In addition to their speed, they are also small devices that can have more number of devices in unit area. In this work, it is aimed design and develop a device which can harvest and detect IR radiation.

  4. Development of Real-Time Thickness Measuring System for Insulated Pipeline Using Gamma-ray

    International Nuclear Information System (INIS)

    Jang, Ji Hoon; Kim, Byung Joo; Cho, Kyung Shik; Kim, Gi Dong

    2002-01-01

    By this study, on-line real-time radiometric system was developed using a 64 channels linear array of solid state detectors to measure wall thickness of insulated piping system. This system uses an Ir-192 as a gamma ray source and detector is composed of BGO scintillator and photodiode. Ir-192 gamma ray source and linear detector array mounted on a computer controlled robotic crawler. The Ir-192 gamma ray source is located on one side of the piping components and the detector array on the other side. The individual detectors of the detector array measure the intensity of the gamma rays after passing through the walls and the insulation of the piping component under measurement. The output of the detector array is amplified by amplifier and transmitted to the computer through cable. This system collects and analyses the data from the detector array in real-time as the crawler travels over the piping system. The maximum measurable length of pipe is 120cm/min. in the case of 1mm scanning interval

  5. Labeling and advertising of home insulation

    Energy Technology Data Exchange (ETDEWEB)

    1978-07-01

    This staff report, prepared by the F.T.C.'s Bureau of Consumer Protection for Commission review, includes recommendations as to the final form of a trade regulation rule relating to the labeling and advertising of home insulation. Because of marketing abuses which accompanied the rising demand for home insulation, there has been broad support for a rule requiring information disclosures to help purchasers of home insulation to make an informed decision. The Commission, to provide such rule as quickly as possible, undertook its rulemaking proceeding under its new expedited rulemaking procedure. The rule was proposed on November 18, 1977, and, following a two-month period for written comments, four weeks of hearings were held in Washington, D.C. in February 1978. The record, contributed to by a variety of interests, shows that consumers do not know how to shop for home insulation. The staff-recommended rule, among other things, would require that insulation be tested and R-values (a measure of insulation's ability to retain heat) disclosed on labels and in advertising. To facilitate comparison shopping, the industry would also be required to furnish consumers with fact sheets describing, on a product-to-product basis, factors that can reduce the R-value of insulation.

  6. Slab edge insulating form system and methods

    Science.gov (United States)

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

    2009-10-06

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

  7. Electrical insulator requirements for mirror fusion reactors

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  8. Excavationless Exterior Foundation Insulation Field Study

    Energy Technology Data Exchange (ETDEWEB)

    Schirber, T.; Mosiman, G.; Ojczyk, C.

    2014-10-01

    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 liquid 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.

  9. Excavationless Exterior Foundation Insulation Field Study

    Energy Technology Data Exchange (ETDEWEB)

    Schirber, T. [NorthernSTAR, Minneaplolis, MN (United States); Mosiman, G. [NorthernSTAR, Minneaplolis, MN (United States); Ojczyk, C. [NorthernSTAR, Minneaplolis, MN (United States)

    2014-09-01

    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 liquid insulating foam. The team was able to excavate a continuous 4 inches wide by 4 feet to 5 feet 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.

  10. Specific features of the photoconductivity of semi-insulating cadmium telluride

    Energy Technology Data Exchange (ETDEWEB)

    Golubyatnikov, V. A.; Grigor’ev, F. I.; Lysenko, A. P., E-mail: aplysenko@hse.ru; Strogankova, N. I.; Shadov, M. B. [National Research University Higher School of Economics, Moscow Institute of Electronics and Mathematics (Russian Federation); Belov, A. G. [OAO GIREDMET State Research and Design Institute of the Rare-Metal Industry (Russian Federation)

    2014-12-15

    The effect of local illumination providing a high level of free-carrier injection on the conductivity of a sample of semi-insulating cadmium telluride and on the properties of ohmic contacts to the sample is studied. It is found that, irrespective of the illumination region, the contact resistance of ohmic contacts decreases and the concentration of majority carriers in the sample grows in proportion to the illumination intensity. It is shown that inherent heterogeneities in crystals of semi-insulating semiconductors can be studied by scanning with a light probe.

  11. Estimation of thermal insulation performance in multi-layer insulator for liquid helium pipe

    International Nuclear Information System (INIS)

    Shibanuma, Kiyoshi; Kuriyama, Masaaki; Shibata, Takemasa

    1991-01-01

    For a multi-layer insulator around the liquid helium pipes for cryopumps of JT-60 NBI, a multi-layer insulator composed of 10 layers, which can be wound around the pipe at the same time and in which the respective layers are in concentric circles by shifting them in arrangement, has been developed and tested. As the result, it was shown that the newly developed multi-layer insulator has better thermal insulation performance than the existing one, i.e. the heat load of the newly developed insulator composed of 10 layers was reduced to 1/3 the heat load of the existing insulator, and the heat leak at the joint of the insulator in longitudinal direction of the pipe was negligible. In order to clarify thermal characteristics of the multi-layer insulator, the heat transfer through the insulator has been analyzed considering the radiation heat transfer by the netting spacer between the reflectors, and the temperature dependence on the emissivities and the heat transmission coefficients of these two components of the insulator. The analytical results were in good agreements with the experimental ones, so that the analytical method was shown to be valid. Concerning the influence of the number of layers and the layer density on the insulation performance of the insulator, analytical results showed that the multi-layer insulator with the number of layer about N = 20 and the layer density below 2.0 layer/mm was the most effective for the liquid helium pipe of a JT-60 cryopump. (author)

  12. Insulin resistance in Nigerians with essential hypertension | Akande ...

    African Journals Online (AJOL)

    Homeostasis model assessment (HOMA) was used to determine insulin resistance (IR). Results: The hypertensive subjects had significantly higher fasting insulin and HOMA-IR compared with normotensives (p =0.02 and 0.04) respectively. There were significant correlations between HOMA-IR, BMI, waist and hip ...

  13. Metallic Interface Emerging at Magnetic Domain Wall of Antiferromagnetic Insulator: Fate of Extinct Weyl Electrons

    Directory of Open Access Journals (Sweden)

    Youhei Yamaji

    2014-05-01

    Full Text Available Topological insulators, in contrast to ordinary semiconductors, accompany protected metallic surfaces described by Dirac-type fermions. Here, we theoretically show that another emergent two-dimensional metal embedded in the bulk insulator is realized at a magnetic domain wall. The domain wall has long been studied as an ingredient of both old-fashioned and leading-edge spintronics. The domain wall here, as an interface of seemingly trivial antiferromagnetic insulators, emergently realizes a functional interface preserved by zero modes with robust two-dimensional Fermi surfaces, where pyrochlore iridium oxides proposed to host the condensed-matter realization of Weyl fermions offer such examples at low temperatures. The existence of in-gap states that are pinned at domain walls, theoretically resembling spin or charge solitons in polyacetylene, and protected as the edges of hidden one-dimensional weak Chern insulators characterized by a zero-dimensional class-A topological invariant, solves experimental puzzles observed in R_{2}Ir_{2}O_{7} with rare-earth elements R. The domain wall realizes a novel quantum confinement of electrons and embosses a net uniform magnetization that enables magnetic control of electronic interface transports beyond the semiconductor paradigm.

  14. Standard Test Methods for Wet Insulation Integrity Testing of Photovoltaic Modules

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 These test methods provide procedures to determine the insulation resistance of a photovoltaic (PV) module, i.e. the electrical resistance between the module's internal electrical components and its exposed, electrically conductive, non-current carrying parts and surfaces. 1.2 The insulation integrity procedures are a combination of wet insulation resistance and wet dielectric voltage withstand test procedures. 1.3 These procedures are similar to and reference the insulation integrity test procedures described in Test Methods E 1462, with the difference being that the photovoltaic module under test is immersed in a wetting solution during the procedures. 1.4 These test methods do not establish pass or fail levels. The determination of acceptable or unacceptable results is beyond the scope of these test methods. 1.5 The values stated in SI units are to be regarded as the standard. 1.6 There is no similar or equivalent ISO standard. 1.7 This standard does not purport to address all of the safety conce...

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

    Science.gov (United States)

    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.

  16. Innovations in IR projector arrays

    Science.gov (United States)

    Cole, Barry E.; Higashi, B.; Ridley, Jeff A.; Holmen, J.; Newstrom, K.; Zins, C.; Nguyen, K.; Weeres, Steven R.; Johnson, Burgess R.; Stockbridge, Robert G.; Murrer, Robert Lee; Olson, Eric M.; Bergin, Thomas P.; Kircher, James R.; Flynn, David S.

    2000-07-01

    In the past year, Honeywell has developed a 512 X 512 snapshot scene projector containing pixels with very high radiance efficiency. The array can operate in both snapshot and raster mode. The array pixels have near black body characteristics, high radiance outputs, broad band performance, and high speed. IR measurements and performance of these pixels will be described. In addition, a vacuum probe station that makes it possible to select the best die for packaging and delivery based on wafer level radiance screening, has been developed and is in operation. This system, as well as other improvements, will be described. Finally, a review of the status of the present projectors and plans for future arrays is included.

  17. Measure Guideline. Hybrid Foundation Insulation Retrofits

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-01

    This measure guideline provides recommendations for designs and variations for retrofit hybrid assemblies in improving interior foundation insulation and water management of basements. Variations include closed cell spray foam (ccSPF) with membrane waterproofing or air gap membrane drainage layers, rigid board foam insulation at flat walls (cast concrete or CMU block), a “partial drainage” detail making use of the bulk water drainage that occurs through the field of a rubble stone wall, and non-drained spray foam assemblies (including slab insulation).

  18. Measure Guideline: Hybrid Foundation Insulation Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, K.; Lstiburek, J.

    2012-05-01

    This measure guideline provides recommendations for designs and variations for retrofit hybrid assemblies in improving interior foundation insulation and water management of basements. Variations include closed cell spray foam (ccSPF) with membrane waterproofing or air gap membrane drainage layers, rigid board foam insulation at flat walls (cast concrete or CMU block), a 'partial drainage' detail making use of the bulk water drainage that occurs through the field of a rubble stone wall, and non-drained spray foam assemblies (including slab insulation).

  19. External insulation with cellular plastic materials

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt; Nielsen, Anker

    2014-01-01

    External thermal insulation composite systems (ETICS) can be used as extra insulation of existing buildings. The system can be made of cellular plastic materials or mineral wool. There is a European Technical guideline, ETAG 004, that describe the tests that shall be conducted on such systems....... This paper gives a comparison of systems with mineral wool and cellular plastic, based on experience from practice and literature. It is important to look at the details in the system and at long time stability of the properties such as thermal insulation, moisture and fire. Investigation of fire properties...

  20. Silicon on insulator self-aligned transistors

    Science.gov (United States)

    McCarthy, Anthony M.

    2003-11-18

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

  1. Sharp superconductor-insulator transition in short wires

    International Nuclear Information System (INIS)

    Meidan, Dganit; Oreg, Yuval; Refael, Gil; Smith, Robert A.

    2008-01-01

    Recent experiments on short MoGe nanowires show a sharp superconductor-insulator transition tuned by the normal state resistance of the wire, with a critical resistance of R c ∼ R Q = h/(4e 2 ). These results are at odds with a broad range of theoretical work on Josephson-like systems that predicts a smooth transition, tuned by the value of the resistance that shunts the junction. We develop a self-consistent renormalization group treatment of interacting phase-slips and their dual counterparts, correlated cooper pair tunneling, beyond the dilute approximation. This analysis leads to a very sharp transition with a critical resistance of R Q . The addition of the quasi-particles' resistance at finite temperature leads to a quantitative agreement with the experimental results. This self-consistent renormalization group method should also be applicable to other physical systems that can be mapped onto similar sine-Gordon models, in the previously inaccessible intermediate-coupling regime

  2. STATYBINIŲ MEDŽIAGŲ KONKURENCINGUMAS IR TENDENCIJOS

    OpenAIRE

    Kontrimas, Robertas

    2010-01-01

    Darbe analizuojamas statybinių medžiagų konkurencingumas, nustatyti statybinių medžiagų konkurencingumą įtakojantys veiksniai ir pateikti pasiūlymai rinkos gerinimui. Pasitvirtino hipotezė, kad statybinių medžiagų paklausą ir kainas įtakoja klientų poreikiai ir jų finansinės galimybės, tačiau pasaulinės krizės įtaka yra labai ženkli,. Atlikta darbuotojų ir pirkėjų apklausa padėjo nustatyti, kokios statybinės medžiagos dažniausiai yra perkamos, kaip klientai ir darbuotojai vertina įmonę ir jos...

  3. Hermann agreement updates IRS guidelines for incentives.

    Science.gov (United States)

    Broccolo, B M; Peregrine, M W

    1995-01-01

    The October 1994 agreement between the Internal Revenue Service (IRS) and Hermann Hospital of Houston, Texas, elucidates current IRS policy on physician recruitment incentives. The IRS distinguishes between the recruiting and the retention of physicians and perimts incentives beyond reasonable compensation in the former but not the latter circumstance. This new agreement, while not legally precedential, nevertheless provides guidance for healthcare organizations seeking safe harbor protection.

  4. High-pressure versus isoelectronic doping effect on the honeycomb iridate Na2IrO3

    Science.gov (United States)

    Hermann, V.; Ebad-Allah, J.; Freund, F.; Pietsch, I. M.; Jesche, A.; Tsirlin, A. A.; Deisenhofer, J.; Hanfland, M.; Gegenwart, P.; Kuntscher, C. A.

    2017-11-01

    We study the effect of isoelectronic doping and external pressure in tuning the ground state of the honeycomb iridate Na2IrO3 by combining optical spectroscopy with synchrotron x-ray diffraction measurements on single crystals. The obtained optical conductivity of Na2IrO3 is discussed in terms of a Mott-insulating picture versus the formation of quasimolecular orbitals and in terms of Kitaev interactions. With increasing Li content x , (Na1 -xLix )2IrO3 moves deeper into the Mott-insulating regime, and there are indications that up to a doping level of 24% the compound comes closer to the Kitaev limit. The optical conductivity spectrum of single-crystalline α -Li2IrO3 does not follow the trends observed for the series up to x =0.24 . There are strong indications that α -Li2IrO3 is not as close to the Kitaev limit as Na2IrO3 and lies closer to the quasimolecular orbital picture instead. Except for the pressure-induced hardening of the phonon modes, the optical properties of Na2IrO3 seem to be robust against external pressure. Possible explanations of the unexpected evolution of the optical conductivity with isolectronic doping and the drastic change between x =0.24 and x =1 are given by comparing the pressure-induced changes of lattice parameters and the optical conductivity with the corresponding changes induced by doping.

  5. Spin-transport-phenomena in metals, semiconductors, and insulators

    Energy Technology Data Exchange (ETDEWEB)

    Althammer, Matthias Klaus

    2012-07-19

    Assuming that one could deterministically inject, transport, manipulate, store and detect spin information in solid state devices, the well-established concepts of charge-based electronics could be transferred to the spin realm. This thesis explores the injection, transport, manipulation and storage of spin information in metallic conductors, semiconductors, as well as electrical insulators. On the one hand, we explore the spin-dependent properties of semiconducting zinc oxide thin films deposited via laser-molecular beam epitaxy (laser-MBE). After demonstrating that the zinc oxide films fabricated during this thesis have excellent structural, electrical, and optical properties, we investigate the spin-related properties by optical pump/probe, electrical injection/optical detection, and all electrical spin valve-based experiments. The two key results from these experiments are: (i) Long-lived spin states with spin dephasing times of 10 ns at 10 K related to donor bound excitons can be optically addressed. (ii) The spin dephasing times relevant for electrical transport-based experiments are {<=} 2 ns at 10 K and are correlated with structural quality. On the other hand we focus on two topics of current scientific interest: the comparison of the magnetoresistance to the magnetothermopower of conducting ferromagnets, and the investigation of pure spin currents generated in ferromagnetic insulator/normal metal hybrid structures. We investigate the magnetoresistance and magnetothermopower of gallium manganese arsenide and Heusler thin films as a function of external magnetic field orientation. Using a series expansion of the resistivity and Seebeck tensors and the inherent symmetry of the sample's crystal structure, we show that a full quantitative extraction of the transport tensors from such experiments is possible. Regarding the spin currents in ferromagnetic insulator/normal metal hybrid structures we studied the spin mixing conductance in yttrium iron garnet

  6. Healthy Chilean Adolescents with HOMA-IR ≥ 2.6 Have Increased Cardiometabolic Risk: Association with Genetic, Biological, and Environmental Factors

    Directory of Open Access Journals (Sweden)

    R. Burrows

    2015-01-01

    Full Text Available Objective. To determine the optimal cutoff of the homeostasis model assessment-insulin resistance (HOMA-IR for diagnosis of the metabolic syndrome (MetS in adolescents and examine whether insulin resistance (IR, determined by this method, was related to genetic, biological, and environmental factors. Methods. In 667 adolescents (16.8 ± 0.3 y, BMI, waist circumference, glucose, insulin, adiponectin, diet, and physical activity were measured. Fat and fat-free mass were assessed by dual-energy X-ray absorptiometry. Family history of type 2 diabetes (FHDM was reported. We determined the optimal cutoff of HOMA-IR to diagnose MetS (IDF criteria using ROC analysis. IR was defined as HOMA-IR values above the cutoff. We tested the influence of genetic, biological, and environmental factors on IR using logistic regression analyses. Results. Of the participants, 16% were obese and 9.4 % met criteria for MetS. The optimal cutoff for MetS diagnosis was a HOMA-IR value of 2.6. Based on this value, 16.3% of participants had IR. Adolescents with IR had a significantly higher prevalence of obesity, abdominal obesity, fasting hyperglycemia, and MetS compared to those who were not IR. FHDM, sarcopenia, obesity, and low adiponectin significantly increased the risk of IR. Conclusions. In adolescents, HOMA-IR ≥ 2.6 was associated with greater cardiometabolic risk.

  7. Healthy Chilean Adolescents with HOMA-IR ≥ 2.6 Have Increased Cardiometabolic Risk: Association with Genetic, Biological, and Environmental Factors.

    Science.gov (United States)

    Burrows, R; Correa-Burrows, P; Reyes, M; Blanco, E; Albala, C; Gahagan, S

    2015-01-01

    To determine the optimal cutoff of the homeostasis model assessment-insulin resistance (HOMA-IR) for diagnosis of the metabolic syndrome (MetS) in adolescents and examine whether insulin resistance (IR), determined by this method, was related to genetic, biological, and environmental factors. In 667 adolescents (16.8 ± 0.3 y), BMI, waist circumference, glucose, insulin, adiponectin, diet, and physical activity were measured. Fat and fat-free mass were assessed by dual-energy X-ray absorptiometry. Family history of type 2 diabetes (FHDM) was reported. We determined the optimal cutoff of HOMA-IR to diagnose MetS (IDF criteria) using ROC analysis. IR was defined as HOMA-IR values above the cutoff. We tested the influence of genetic, biological, and environmental factors on IR using logistic regression analyses. Of the participants, 16% were obese and 9.4 % met criteria for MetS. The optimal cutoff for MetS diagnosis was a HOMA-IR value of 2.6. Based on this value, 16.3% of participants had IR. Adolescents with IR had a significantly higher prevalence of obesity, abdominal obesity, fasting hyperglycemia, and MetS compared to those who were not IR. FHDM, sarcopenia, obesity, and low adiponectin significantly increased the risk of IR. In adolescents, HOMA-IR ≥ 2.6 was associated with greater cardiometabolic risk.

  8. 4PS/insulin receptor substrate (IRS)-2 is the alternative substrate of the insulin receptor in IRS-1-deficient mice.

    Science.gov (United States)

    Patti, M E; Sun, X J; Bruening, J C; Araki, E; Lipes, M A; White, M F; Kahn, C R

    1995-10-20

    Insulin receptor substrate-1 (IRS-1) is the major cytoplasmic substrate of the insulin and insulin-like growth factor (IGF)-1 receptors. Transgenic mice lacking IRS-1 are resistant to insulin and IGF-1, but exhibit significant residual insulin action which corresponds to the presence of an alternative high molecular weight substrate in liver and muscle. Recently, Sun et al. (Sun, X.-J., Wang, L.-M., Zhang, Y., Yenush, L. P., Myers, M. G., Jr., Glasheen, E., Lane, W.S., Pierce, J. H., and White, M. F. (1995) Nature 377, 173-177) purified and cloned 4PS, the major substrate of the IL-4 receptor-associated tyrosine kinase in myeloid cells, which has significant structural similarity to IRS-1. To determine if 4PS is the alternative substrate of the insulin receptor in IRS-1-deficient mice, we performed immunoprecipitation, immunoblotting, and phosphatidylinositol (PI) 3-kinase assays using specific antibodies to 4PS. Following insulin stimulation, 4PS is rapidly phosphorylated in liver and muscle, binds to the p85 subunit of PI 3-kinase, and activates the enzyme. Insulin stimulation also results in the association of 4PS with Grb 2 in both liver and muscle. In IRS-1-deficient mice, both the phosphorylation of 4PS and associated PI 3-kinase activity are enhanced, without an increase in protein expression. Immunodepletion of 4PS from liver and muscle homogenates removes most of the phosphotyrosine-associated PI 3-kinase activity in IRS-1-deficient mice. Thus, 4PS is the primary alternative substrate, i.e. IRS-2, which plays a major role in physiologic insulin signal transduction via both PI 3-kinase activation and Grb 2/Sos association. In IRS-1-deficient mice, 4PS/IRS-2 provides signal transduction to these two major pathways of insulin signaling.

  9. Validity and reproducibility of HOMA-IR, 1/HOMA-IR, QUICKI and McAuley's indices in patients with hypertension and type II diabetes.

    Science.gov (United States)

    Sarafidis, P A; Lasaridis, A N; Nilsson, P M; Pikilidou, M I; Stafilas, P C; Kanaki, A; Kazakos, K; Yovos, J; Bakris, G L

    2007-09-01

    The aim of this study was to evaluate the validity and reliability of homeostasis model assessment-insulin resistance (HOMA-IR) index, its reciprocal (1/HOMA-IR), quantitative insulin sensitivity check index (QUICKI) and McAuley's index in hypertensive diabetic patients. In 78 patients with hypertension and type II diabetes glucose, insulin and triglyceride levels were determined after a 12-h fast to calculate these indices, and insulin sensitivity (IS) was measured with the hyperinsulinemic euglycemic clamp technique. Two weeks later, subjects had again their glucose, insulin and triglycerides measured. Simple and multiple linear regression analysis were applied to assess the validity of these indices compared to clamp IS and coefficients of variation between the two visits were estimated to assess their reproducibility. HOMA-IR index was strongly and inversely correlated with the basic IS clamp index, the M-value (r=-0.572, PHOMA-IR and QUICKI indices were positively correlated with the M-value (r=0.342, PHOMA-IR was the best fit of clamp-derived IS. Coefficients of variation between the two visits were 23.5% for HOMA-IR, 19.2% for 1/HOMA-IR, 7.8% for QUICKI and 15.1% for McAuley's index. In conclusion, HOMA-IR, 1/HOMA-IR and QUICKI are valid estimates of clamp-derived IS in patients with hypertension and type II diabetes, whereas the validity of McAuley's index needs further evaluation. QUICKI displayed better reproducibility than the other indices.

  10. OH/IR stars in the Galaxy

    International Nuclear Information System (INIS)

    Baud, B.

    1978-01-01

    Radio astronomical observations leading to the discovery of 71 OH/IR sources are described in this thesis. These OH/IR sources are characterized by their double peaked OH emission profile at a wavelength of 18 cm and by their strong IR infrared emission. An analysis of the distribution and radial velocities of a number of previously known and new OH/IR sources was performed. The parameter ΔV (the velocity separation between two emission peaks of the 18 cm line profile) was found to be a good criterion for a population classification with respect to stellar age

  11. Repeatability of Cryogenic Multilayer Insulation

    Science.gov (United States)

    Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

    2017-12-01

    Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation (MLI) has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five Glenn Research Center (GRC) provided coupons with 25 layers was shown to be +/- 8.4% whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0%. A second group of 10 coupons has been fabricated by Yetispace and tested by Florida State University, the repeatability between coupons has been shown to be +/- 15-25%. Based on detailed statistical analysis, the data has been shown to be statistically significant.

  12. Spintronics Based on Topological Insulators

    Science.gov (United States)

    Fan, Yabin; Wang, Kang L.

    2016-10-01

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

  13. Topological insulators Dirac equation in condensed matter

    CERN Document Server

    Shen, Shun-Qing

    2017-01-01

    This new edition presents a unified description of these insulators from one to three dimensions based on the modified Dirac equation. It derives a series of solutions of the bound states near the boundary, and describes the current status of these solutions. Readers are introduced to topological invariants and their applications to a variety of systems from one-dimensional polyacetylene, to two-dimensional quantum spin Hall effect and p-wave superconductors, three-dimensional topological insulators and superconductors or superfluids, and topological Weyl semimetals, helping them to better understand this fascinating field. To reflect research advances in topological insulators, several parts of the book have been updated for the second edition, including: Spin-Triplet Superconductors, Superconductivity in Doped Topological Insulators, Detection of Majorana Fermions and so on. In particular, the book features a new chapter on Weyl semimetals, a topic that has attracted considerable attention and has already b...

  14. KSI's Cross Insulated Core Transformer Technology

    International Nuclear Information System (INIS)

    Uhmeyer, Uwe

    2009-01-01

    Cross Insulated Core Transformer (CCT) technology improves on Insulated Core Transformer (ICT) implementations. ICT systems are widely used in very high voltage, high power, power supply systems. In an ICT transformer ferrite core sections are insulated from their neighboring ferrite cores. Flux leakage is present at each of these insulated gaps. The flux loss is raised to the power of stages in the ICT design causing output voltage efficiency to taper off with increasing stages. KSI's CCT technology utilizes a patented technique to compensate the flux loss at each stage of an ICT system. Design equations to calculate the flux compensation capacitor value are presented. CCT provides corona free operation of the HV stack. KSI's CCT based High Voltage power supply systems offer high efficiency operation, high frequency switching, low stored energy and smaller size over comparable ICT systems.

  15. Cryogenic Insulation Standard Data and Methodologies

    Data.gov (United States)

    National Aeronautics and Space Administration — Extending some recent developments in the area of technical consensus standards for cryogenic thermal insulation systems, a preliminary Inter-Laboratory Study of...

  16. Electrical breakdown studies with Mycalex insulators

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  17. Characterization techniques for ion bombarded insulators

    International Nuclear Information System (INIS)

    Borders, J.A.

    1987-01-01

    The chapter gives a comprehensive review of the experimental methods for the analysis of ion-bombarded insulators including optical and structural methods, resonance, energetic ion methods, and surface techniques. 48 refs.; 34 figs

  18. Corrosion-under-insulation (CUI) guidelines

    CERN Document Server

    Staff, European Federation of Corrosion; Winnik, S

    2014-01-01

    Corrosion under insulation (CUI) refers to the external corrosion of piping and vessels that occurs underneath externally clad/jacketed insulation as a result of the penetration of water. By its very nature CUI tends to remain undetected until the insulation and cladding/jacketing is removed to allow inspection or when leaks occur. CUI is a common problem shared by the refining, petrochemical, power, industrial, onshore and offshore industries. The European Federation of Corrosion (EFC) Working Parties WP13 and WP15 have worked to provide guidelines on managing CUI together with a number of major European refining, petrochemical and offshore companies including BP, Chevron-Texaco, Conoco-Phillips, ENI, Exxon-Mobil, IFP, MOL, Scanraff, Statoil, Shell, Total and Borealis. The guidelines within this document are intended for use on all plants and installations that contain insulated vessels, piping and equipment. The guidelines cover a risk-based inspection methodology for CUI, inspection techniques (including n...

  19. (ajst) effects of ground insulation and greenhouse

    African Journals Online (AJOL)

    NORBERT OPIYO AKECH

    and quality of biogas generation from dairy cattle dung. The effects ... Therefore ground insulation of plastic biogas digester under greenhouse conditions significantly enhances ..... The low values obtained did not suggest failure of the system ...

  20. Improved thermal monitoring of rotating machine insulation

    International Nuclear Information System (INIS)

    Stone, G.C.; Sedding, H.G.; Bernstein, B.S.

    1991-01-01

    Aging of motor and generator insulation is most often induced as a result of operation at high temperatures. In spite of this knowledge, stator and rotor temperatures are only crudely monitored in existing machines. In EPRI project RP2577-1, three new means of detecting machine temperatures were successfully developed. Two of the techniques, the Electronic Rotor Temperature Sensor and the Passive Rotor Temperature Sensor, were specifically developed to give point temperature readings on turbine generator rotor windings. The Insulation Sniffer allows operators to determine when any electrical insulation in a motor is overheating. Another electronic device, called the Thermal Life Indicator, helps operators and maintenance personnel determine how accumulated operation has affected the remaining life of the insulation in rotating machines. These new devices permit nuclear station operators to avoid hazardous operating conditions and will help to determine priorities for maintenance and plant life extension programs