WorldWideScience

Sample records for resistance heating method

  1. Entropy resistance minimization: An alternative method for heat exchanger analyses

    International Nuclear Information System (INIS)

    Cheng, XueTao

    2013-01-01

    In this paper, the concept of entropy resistance is proposed based on the entropy generation analyses of heat transfer processes. It is shown that smaller entropy resistance leads to larger heat transfer rate with fixed thermodynamic force difference and smaller thermodynamic force difference with fixed heat transfer rate, respectively. For the discussed two-stream heat exchangers in which the heat transfer rates are not given and the three-stream heat exchanger with prescribed heat capacity flow rates and inlet temperatures of the streams, smaller entropy resistance leads to larger heat transfer rate. For the two-stream heat exchangers with fixed heat transfer rate, smaller entropy resistance leads to larger effectiveness. Furthermore, it is shown that smaller values of the concepts of entropy generation numbers and modified entropy generation number do not always correspond to better performance of the discussed heat exchangers. - Highlights: • The concept of entropy resistance is defined for heat exchangers. • The concepts based on entropy generation are used to analyze heat exchangers. • Smaller entropy resistance leads to better performance of heat exchangers. • The applicability of entropy generation minimization is conditional

  2. A review of methods to evaluate borehole thermal resistances in geothermal heat-pump systems

    Energy Technology Data Exchange (ETDEWEB)

    Lamarche, Louis; Kajl, Stanislaw; Beauchamp, Benoit [Ecole de Technologie Superieure, 1100 Notre-Dame Ouest, Montreal (Canada)

    2010-06-15

    In the design of a ground-source heat pump (GSHP) system, the heat transfer from the fluid to the ground is influenced by the thermal borehole resistance between the fluid and the borehole surface and also by the interference resistance between the two (or four) pipes inside the borehole. Several authors have proposed empirical and theoretical relations to evaluate these resistances as well as methods to evaluate them experimentally. The paper compares the different approaches and proposes good practice to evaluate the resistances. The impact of the different approaches on the design of heat exchanger is also examined. Two-dimensional and fully three-dimensional numerical simulations are used to evaluate the different methods. A new method is also proposed to evaluate the borehole resistances from in situ tests. (author)

  3. Heat-resistant materials

    CERN Document Server

    1997-01-01

    This handbook covers the complete spectrum of technology dealing with heat-resistant materials, including high-temperature characteristics, effects of processing and microstructure on high-temperature properties, materials selection guidelines for industrial applications, and life-assessment methods. Also included is information on comparative properties that allows the ranking of alloy performance, effects of processing and microstructure on high-temperature properties, high-temperature oxidation and corrosion-resistant coatings for superalloys, and design guidelines for applications involving creep and/or oxidation. Contents: General introduction (high-temperature materials characteristics, and mechanical and corrosion properties, and industrial applications); Properties of Ferrous Heat-Resistant Alloys (carbon, alloy, and stainless steels; alloy cast irons; and high alloy cast steels); Properties of superalloys (metallurgy and processing, mechanical and corrosion properties, degradation, and protective coa...

  4. Synthesis and characterization of large WO{sub 3} sheets synthesized by resistive heating method

    Energy Technology Data Exchange (ETDEWEB)

    Filippo, Emanuela, E-mail: emanuela.filippo@unisalento.it [Department of Engineering for Innovation, University of Salento, Monteroni Street, Lecce I-73100 Italy (Italy); Tepore, Marco [Department of Engineering for Innovation, University of Salento, Monteroni Street, Lecce I-73100 Italy (Italy); Baldassarre, Francesca [Department of Cultural Heritage, University of Salento, Lecce I-73100 Italy (Italy); Quarta, Gianluca; Calcagnile, Lucio [Department of Engineering for Innovation, University of Salento, Monteroni Street, Lecce I-73100 Italy (Italy); Guascito, Maria Rachele [DiSTeBA, University of Salento, Lecce I-73100 Italy (Italy); Tepore, Antonio [Department of Cultural Heritage, University of Salento, Lecce I-73100 Italy (Italy)

    2015-09-01

    A simple, low-cost method is presented to grow tungsten oxide large sheets simply by resistively heating a pure tungsten filament under air/water vapor flow. The obtained structures were studied using scanning and transmission electron microscopy, selected area diffraction, X Ray diffraction, Raman and X-ray photoelectron spectroscopy, photoluminescence and zeta potential measurements. SEM observations revealed that sheets formed by broadening of the wires/belts over longer growth period. Photoluminescence measurements showed that tungsten oxide sheets had an intense visible emission band. - Highlights: • WO{sub 3} large sheets were prepared by resistively heating a W filament. • WO{sub 3} sheets were carefully characterized. • Formation mechanism of sheets was studied. • WO{sub 3} sheets had an intense visible emission band at 462 nm.

  5. Study on creep behavior of Grade 91 heat-resistant steel using theta projection method

    Science.gov (United States)

    Ren, Facai; Tang, Xiaoying

    2017-10-01

    Creep behavior of Grade 91 heat-resistant steel used for steam cooler was characterized using the theta projection method. Creep tests were conducted at the temperature of 923K under the stress ranging from 100-150MPa. Based on the creep curve results, four theta parameters were established using a nonlinear least square fitting method. Four theta parameters showed a good linearity as a function of stress. The predicted curves coincided well with the experimental data and creep curves were also modeled to the low stress level of 60MPa.

  6. Validation of the method for determination of the thermal resistance of fouling in shell and tube heat exchangers

    International Nuclear Information System (INIS)

    Markowski, Mariusz; Trafczynski, Marian; Urbaniec, Krzysztof

    2013-01-01

    Highlights: • Heat recovery in a heat exchanger network (HEN). • A novel method for on-line determination of the thermal resistance of fouling is presented. • Details are developed for shell and tube heat exchangers. • The method was validated and sensibility analysis was carried out. • Developed approach allows long-term monitoring of changes in the HEN efficiency. - Abstract: A novel method for on-line determination of the thermal resistance of fouling in shell and tube heat exchangers is presented. It can be applied under the condition that the data on pressure, temperature, mass flowrate and thermophysical properties of both heat-exchanging media are continuously available. The calculation algorithm for use in the novel method is robust and ensures reliable determination of the thermal resistance of fouling even if the operating parameters fluctuate. The method was validated using measurement data retrieved from the operation records of a heat exchanger network connected with a crude distillation unit rated 800 t/h. Sensibility analysis of the method was carried out and the calculated values of the thermal resistance of fouling were critically reviewed considering the results of qualitative evaluation of fouling layers in the exchangers inspected during plant overhaul

  7. Effect of method for plastic working procedure on deformability of heat resisting alloys

    International Nuclear Information System (INIS)

    Nikiforov, B.A.

    1979-01-01

    Presented are the results of investigation of deformability of the heat resisting KhN56BMTYUR, KhN67BMTYU alloys at the wire drawing and rolling. The deformability has been evaluated by the results of macro- and micro-analyses, by the change of metal density and mechanical properties in the process of deformation. It is found that by the rolling it is possible to obtain 3-6 mm diameter wire with high surface quality avoiding intermediate heat treatments, cleaning and grinding the wire surface. The production of the wire of the same diameter by drawing is connected with intermediate heat treatments and with the presence of surface and internal defects in the form of longitudinal and transverse cracks, tears, laminations

  8. [Properties of NiTi wires with direct electric resistance heat treatment method in three-point bending tests].

    Science.gov (United States)

    Wang, Hong-mei; Wang, Bang-kang; Ren, Chao-chao; Bai, Yu-xing

    2011-03-01

    To investigate the mechanical properties of Ni-Ti wires with direct electric resistance heat treatment (DERHT) method in three-point bending tests. Two superelastic Ni-Ti wires (wire A: Smart SE, wire B: SENTALLOY SE, 0.406 mm × 0.559 mm) and 2 heat-actived Ni-Ti wires (wire C: Smart SM, wire D: L&H TITAN, 0.406 mm × 0.559 mm) were selected. They were heat-treated using the DERHT method by a controlled electric current (6.36 A) applied for different period of time [0 (control), 1.0, 1.5, 2.0, 2.5 seconds). Then, a three-point bending test was performed under controlled temperature (37°C) to examine the relationships between the deflection and the load in the bending of wires. After DERHT treatment, the plateau in the force-deflection curve of superelastic Ni-Ti wires and heat-activated Ni-Ti wires were increased. When the wires were heated for 2.0 seconds and deflected to 1.5 mm, the loading force of A, B, C and D Ni-Ti wires increased from (3.85 ± 0.11), (3.62 ± 0.07), (3.28 ± 0.09), (2.91 ± 0.23) N to (4.33 ± 0.07), (4.07 ± 0.05), (4.52 ± 0.08), (3.27 ± 0.15) N respectively. DERHT method is very convenient for clinical use. It is possible to change the arch form and superelastic force of NiTi wires. The longer the heating time is, the more the superelastic characteristics of the wires are altered.

  9. A method for producing electrolyte and heat resistant drilling muds from bentonite clays

    Energy Technology Data Exchange (ETDEWEB)

    Koyev, K; Bedelcheva, A; Uzunova, I

    1979-01-01

    A method is developed for producing clay suspensions, which are resistant to electrolytes, high temperature and pressure, on the basis of bentonite clays with a high content of montmorillonite. The method is based on the subsequent introduction into the suspension of magnesium chloride (calcium chloride) and sodium chloride with intense mixing and maintenance of the high viscosity of the clay mass. The electrolytes are added in a specific order and volume: the magnesium chloride or calcium chloride at 1-3% and the sodium chloride at approximately 30%. The clay suspensions are characterized by high SNS and filtration (40 cm/sup 3/ in 30 min). The operational indicators may be regulated so that they remain in accordance with the required standards.

  10. Heat resistant protective hand covering

    Science.gov (United States)

    Tschirch, R. P.; Sidman, K. R.; Arons, I. J. (Inventor)

    1984-01-01

    A heat-resistant aromatic polyamide fiber is described. The outer surface of the shell is coated with a fire-resistant elastomer and liner. Generally conforming and secured to the shell and disposed inwardly of the shell, the liner is made of a felt fabric of temperature-resistant aromatic polymide fiber.

  11. Numerical Simulation of Yttrium Aluminum Garnet(YAG) Single Crystal Growth by Resistance Heating Czochralski(CZ) Method

    Energy Technology Data Exchange (ETDEWEB)

    You, Myeong Hyeon; Cha, Pil Ryung [Kookmin University, Seoul (Korea, Republic of)

    2017-01-15

    Yttrium Aluminum Garnet (YAG) single crystal has received much attention as the high power solid-state laser’s key component in industrial and medical applications. Various growth methods have been proposed, and currently the induction-heating Czochralski (IHCZ) growth method is mainly used to grow YAG single crystal. Due to the intrinsic properties of the IHCZ method, however, the solid/liquid interface has a downward convex shape and a sharp tip at the center, which causes a core defect and reduces productivity. To produce YAG single crystals with both excellent quality and higher yield, it is essential to control the core defects. In this study, using computer simulations we demonstrate that the resistance-heating CZ (RHCZ) method may avoid a downward convex interface and produce core defect free YAG single crystal. We studied the effects of various design parameters on the interface shape and found that there was an optimum combination of design parameter and operating conditions that produced a flat solid-liquid interface.

  12. Resistive Heating in Saturn's Thermosphere

    Science.gov (United States)

    Vriesema, Jess W.; Koskinen, Tommi; Yelle, Roger V.

    2016-10-01

    The thermospheres of the jovian planets are several times hotter than solar heating alone can account for. On Saturn, resistive heating appears sufficient to explain these temperatures in auroral regions, but the particular mechanism(s) responsible for heating the lower latitudes remains unclear. Smith et al. (2005) suggested that electrodynamics of the equatorial region—particularly resistive heating caused by strong electrojet currents—might explain the observed temperatures at low latitudes. Müller-Wodarg et al. (2006) found that their circulation model could reproduce low-latitude temperatures only when they included resistive heating at the poles and applied a uniform, generic heating source globally. Smith et al. (2007) concluded that heating at the poles leads to meridional circulation that cools low latitudes and argued that in-situ heating is required to explain the temperatures at low latitudes.Resistive heating at low latitudes, arising from enhanced current generation driven by thermospheric winds, is a potentially important in-situ heating mechanism. Ion drag caused by low-latitude electrodynamics can modify global circulation and meridional transport of energy. We present an axisymmetric, steady-state formulation of wind-driven electrodynamics to investigate these possibilities throughout Saturn's thermosphere. At present, we assume a dipole magnetic field and neglect any contributions from the magnetosphere. We use ion mixing ratios from the model of Kim et al. (2014) and the observed temperature-pressure profile from Koskinen et al. (2015) to calculate the generalized conductivity tensor as described by Koskinen et al. (2014). Our model solves the coupled equations for charge continuity and Ohm's law with tensor conductivity while enforcing zero current across the boundaries. The resulting partial differential equation is solved for the current density throughout the domain and used to calculate the net resistive heating rate. We demonstrate

  13. Electrical Methods: Resistivity Methods

    Science.gov (United States)

    Surface electrical resistivity surveying is based on the principle that the distribution of electrical potential in the ground around a current-carrying electrode depends on the electrical resistivities and distribution of the surrounding soils and rocks.

  14. Tungsten determination in heat resistant nickel-base-alloys by the method of atomic absorption

    International Nuclear Information System (INIS)

    Gregorczyk, S.; Wycislik, A.

    1980-01-01

    A method of atomic absorption was developed. It allows for the tungsten to be determined in heatresistant nickel-base-alloys within the range 0.01 to 7%. It consists in precipitating tungsten acid in the presence of alkaloids with its following decomposition by hydrofluoric acid in the teflon bomb. (author)

  15. Inductance and resistance measurement method for vessel detection and coil powering in all-surface inductive heating systems composed of outer squircle coils

    Science.gov (United States)

    Kilic, Veli Tayfun; Unal, Emre; Demir, Hilmi Volkan

    2017-05-01

    In this work, we investigate a method proposed for vessel detection and coil powering in an all-surface inductive heating system composed of outer squircle coils. Besides conventional circular coils, coils with different shapes such as outer squircle coils are used for and enable efficient all-surface inductive heating. Validity of the method, which relies on measuring inductance and resistance values of a loaded coil at different frequencies, is experimentally demonstrated for a coil with shape different from conventional circular coil. Simple setup was constructed with a small coil to model an all-surface inductive heating system. Inductance and resistance maps were generated by measuring coil's inductance and resistance values at different frequencies loaded by a plate made of different materials and located at various positions. Results show that in an induction hob for various coil geometries it is possible to detect a vessel's presence, to identify its material type and to specify its position on the hob surface by considering inductance and resistance of the coil measured on at least two different frequencies. The studied method is important in terms of enabling safe, efficient and user flexible heating in an all-surface inductive heating system by automatically detecting the vessel's presence and powering on only the coils that are loaded by the vessel with predetermined current levels.

  16. Thermophysical Properties of Heat Resistant Shielding Material

    International Nuclear Information System (INIS)

    Porter, W.D.

    2004-01-01

    This project was aimed at determining thermal conductivity, specific heat and thermal expansion of a heat resistant shielding material for neutron absorption applications. These data are critical in predicting the structural integrity of the shielding under thermal cycling and mechanical load. The measurements of thermal conductivity and specific heat were conducted in air at five different temperatures (-31 F, 73.4 F, 140 F, 212 F and 302 F). The transient plane source (TPS) method was used in the tests. Thermal expansion tests were conducted using push rod dilatometry over the continuous range from -40 F (-40 C) to 302 F (150 C)

  17. A study on heat resistance of high temperature resistant coating

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Liping; Wang, Xueying; Zhang, Qibin; Qin, Yanlong; Lin, Zhu [Research Institute of Engineering Technology of CNPC, Tianjin (China)

    2005-04-15

    A high temperature resistant coating has been developed, which is mainly for heavy oil production pipes deserved the serious corrosion. The coating has excellent physical and mechanical performance and corrosion resistance at room and high temperature. In order to simulate the underground working condition of heavy oil pipes,the heat resistance of the high temperature resistant coating has been studied. The development and a study on the heat resistance of the DHT high temperature resistance coating have been introduced in this paper

  18. A study on heat resistance of high temperature resistant coating

    International Nuclear Information System (INIS)

    Zhang, Liping; Wang, Xueying; Zhang, Qibin; Qin, Yanlong; Lin, Zhu

    2005-01-01

    A high temperature resistant coating has been developed, which is mainly for heavy oil production pipes deserved the serious corrosion. The coating has excellent physical and mechanical performance and corrosion resistance at room and high temperature. In order to simulate the underground working condition of heavy oil pipes,the heat resistance of the high temperature resistant coating has been studied. The development and a study on the heat resistance of the DHT high temperature resistance coating have been introduced in this paper

  19. NCSX Plasma Heating Methods

    International Nuclear Information System (INIS)

    Kugel, H.W.; Spong, D.; Majeski, R.; Zarnstorff, M.

    2008-01-01

    The National Compact Stellarator Experiment (NCSX) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral beam injection, and radio-frequency (rf). Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, neutral beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The experimental plan requires 3 MW of 50-keV balanced neutral beam tangential injection with pulse lengths of 500 ms for initial experiments, to be upgradeable to pulse lengths of 1.5 s. Subsequent upgrades will add 3MW of neutral beam injection (NBI). This paper discusses the NCSX NBI requirements and design issues and shows how these are provided by the candidate PBX-M NBI system. In addition, estimations are given for beam heating efficiencies, scaling of heating efficiency with machine size and magnetic field level, parameter studies of the optimum beam injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of rf heating by mode conversion ion Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron cyclotron heating. The initial MCIBW heating technique and the design of the rf system lend themselves to current drive, so if current drive became desirable for any reason, only minor modifications to the heating system described here would be needed. The rf system will also be capable of localized ion heating (bulk or tail), and possibly IBW-generated sheared flows

  20. NCSX Plasma Heating Methods

    International Nuclear Information System (INIS)

    Kugel, H.W.; Spong, D.; Majeski, R.; Zarnstorff, M.

    2003-01-01

    The NCSX (National Compact Stellarator Experiment) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral-beam injection, and radio-frequency. Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The plan is to provide 3 MW of 50 keV balanced neutral-beam tangential injection with pulse lengths of 500 msec for initial experiments, and to be upgradeable to pulse lengths of 1.5 sec. Subsequent upgrades will add 3 MW of neutral-beam injection. This Chapter discusses the NCSX neutral-beam injection requirements and design issues, and shows how these are provided by the candidate PBX-M (Princeton Beta Experiment-Modification) neutral-beam injection system. In addition, estimations are given for beam-heating efficiencies, scaling of heating efficiency with machine size an d magnetic field level, parameter studies of the optimum beam-injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of radio-frequency heating by mode-conversion ion-Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron-cyclotron heating. The initial MCIBW heating technique and the design of the radio-frequency system lend themselves to current drive, so that if current drive became desirable for any reason only minor modifications to the heating system described here would be needed. The radio-frequency system will also be capable of localized ion heating (bulk or tail), and possibly ion-Bernstein-wave-generated sheared flows

  1. An Alternative Corrosion Resistance Test Method for Solar Cells and Interconnection Materials Limiting the Number of Long-lasting and Expensive Damp-Heat Climate Chamber Tests

    Energy Technology Data Exchange (ETDEWEB)

    Van Aken, B.B.; Gouwen, R.J.; Veldman, D.; Bende, E.E.; Eerenstein, W. [ECN Solar Energy, Petten (Netherlands)

    2013-06-15

    Damp-heat testing of PV modules is a time-consuming process, taking months. We present an alternative test method: electrochemical noise (EcN) measurements. Data acquisition times vary between minutes for direct exposure to several tens of hours for encapsulated samples. EcN measurements are presented for several solar cell concepts and different environments. We have found that the degradation in damp-heat testing is proportional to the electrochemical noise signal. In conclusion, the electrochemical noise measurements are a fast, versatile tool to test the corrosion resistance of solar cells, which can be tested for different environments including encapsulation.

  2. Heat-resistant inorganic binders.

    Directory of Open Access Journals (Sweden)

    KUDRYAVTSEV Pavel Gennadievich,

    2017-04-01

    Full Text Available The authors consider some aspects of production of inorganic heat-resistant composite materials in which new classes of inorganic binders - the basic salts of various metals – are applied. The possibility to use hydroxochlorides and hydroxonitrates of aluminum, zirconium, chromium and a number of other metals as the binder has been shown. The main products of the thermal decomposition of all types of binders discussed in this paper are nano-dispersed highly refractory oxides. Increased pressure in the manufacture of these materials shifts the position of the minimum of the dependence «production strength – production temperature» in the direction of low temperatures. This effect is caused by decreased film thickness of the binder located between filler particles and hence by increased rate of transfer of the matter to the interface and by facilitated sintering process. Materials based on the systems containing chromium and some other elements in transitional oxidation states are colour. For this reason, they have the worst thermal conductivity under the same heat resistance compared to colorless materials.

  3. Method of determination of temperature and heat resistance of the points on the integrated circuit crystal surface

    Directory of Open Access Journals (Sweden)

    Popov V. M.

    2011-12-01

    Full Text Available Method for visualization of integrated circuit (IC surface temperature by means of the liquid crystal film deposited from solution on its surface is proposed. The boundaries of local regions represent isotherms with corresponding phase transitions. On the base of isotherms positions and consumed by IC power thermal resistances between crystal and environment are determined.

  4. Development of heat-resistant magnetic sensor

    International Nuclear Information System (INIS)

    Takaya, Shigeru; Arakawa, Hisashi; Keyakida, Satoshi

    2013-01-01

    A heat-resistant flux gate magnetic sensor has been developed. Permendur, which has high Curie point, is employed as the magnetic core material and the detection method of the external magnetic field is modified. The characteristics of the developed magnetic sensor up to 500degC were evaluated. The sensor output increased linearly with the external magnetic field in the range of ±5 G and the standard deviation at 500degC was about 0.85G. (author)

  5. HEAT TRANSFER METHOD

    Science.gov (United States)

    Gambill, W.R.; Greene, N.D.

    1960-08-30

    A method is given for increasing burn-out heat fluxes under nucleate boiling conditions in heat exchanger tubes without incurring an increase in pumping power requirements. This increase is achieved by utilizing a spinning flow having a rotational velocity sufficient to produce a centrifugal acceleration of at least 10,000 g at the tube wall. At this acceleration the heat-transfer rate at burn out is nearly twice the rate which can be achieved in a similar tube utilizing axial flow at the same pumping power. At higher accelerations the improvement over axial flow is greater, and heat fluxes in excess of 50 x 10/sup 6/ Btu/hr/sq ft can be achieved.

  6. Design and fabrication of heat resistant multilayers

    International Nuclear Information System (INIS)

    Thorne, J.M.; Knight, L.V.; Peterson, B.G.; Perkins, R.T.; Gray, K.J.

    1986-01-01

    Many promising applications of multilayer x-ray optical elements subject them to intense radiation. This paper discusses the selection of optimal pairs of materials to resist heat damage and presents simulations of multilayer performance under extreme heat loadings

  7. Heat transfer entropy resistance for the analyses of two-stream heat exchangers and two-stream heat exchanger networks

    International Nuclear Information System (INIS)

    Cheng, XueTao; Liang, XinGang

    2013-01-01

    The entropy generation minimization method is often used to analyze heat transfer processes from the thermodynamic viewpoint. In this paper, we analyze common heat transfer processes with the concept of entropy generation, and propose the concept of heat transfer entropy resistance. It is found that smaller heat transfer entropy resistance leads to smaller equivalent thermodynamic force difference with prescribed heat transfer rate and larger heat transfer rate with prescribed equivalent thermodynamic force difference. With the concept of heat transfer entropy resistance, the performance of two-stream heat exchangers (THEs) and two-stream heat exchanger networks (THENs) is analyzed. For the cases discussed in this paper, it is found that smaller heat transfer entropy resistance always leads to better heat transfer performance for THEs and THENs, while smaller values of the entropy generation, entropy generation numbers and revised entropy generation number do not always. -- Highlights: • The concept of entropy resistance is defined. • The minimum entropy resistance principle is developed. • Smaller entropy resistance leads to better heat transfer

  8. Design of a species-specific PCR method for the detection of the heat-resistant fungi Talaromyces macrosporus and Talaromyces trachyspermus.

    Science.gov (United States)

    Yamashita, S; Nakagawa, H; Sakaguchi, T; Arima, T-H; Kikoku, Y

    2018-01-01

    Heat-resistant fungi occur sporadically and are a continuing problem for the food and beverage industry. The genus Talaromyces, as a typical fungus, is capable of producing the heat-resistant ascospores responsible for the spoilage of processed food products. Isocitrate lyase, a signature enzyme of the glyoxylate cycle, is required for the metabolism of non-fermentable carbon compounds, like acetate and ethanol. Here, species-specific primer sets for detection and identification of DNA derived from Talaromyces macrosporus and Talaromyces trachyspermus were designed based on the nucleotide sequences of their isocitrate lyase genes. Polymerase chain reaction (PCR) using a species-specific primer set amplified products specific to T. macrosporus and T. trachyspermus. Other fungal species, such as Byssochlamys fulva and Hamigera striata, which cause food spoilage, were not detected using the Talaromyces-specific primer sets. The detection limit for each species-specific primer set was determined as being 50 pg of template DNA, without using a nested PCR method. The specificity of each species-specific primer set was maintained in the presence of 1,000-fold amounts of genomic DNA from other fungi. The method also detected fungal DNA extracted from blueberry inoculated with T. macrosporus. This PCR method provides a quick, simple, powerful and reliable way to detect T. macrosporus and T. trachyspermus. Polymerase chain reaction (PCR)-based detection is rapid, convenient and sensitive compared with traditional methods of detecting heat-resistant fungi. In this study, a PCR-based method was developed for the detection and identification of amplification products from Talaromyces macrosporus and Talaromyces trachyspermus using primer sets that target the isocitrate lyase gene. This method could be used for the on-site detection of T. macrosporus and T. trachyspermus in the near future, and will be helpful in the safety control of raw materials and in food and beverage

  9. Microbial profile, antibiotic sensitivity and heat resistance of bacterial ...

    African Journals Online (AJOL)

    Aim: This study was aimed at determining the prevalence, antibiotic resistance and heat resistance profile of bacterial isolates obtained from ready to eat roasted beef (suya) sold in Abuja, Nigeria. Methods and Results: Fifty samples of suya were purchased from different vendors within the Federal Capital Territory and ...

  10. Heated Aluminum Tanks Resist Corrosion

    Science.gov (United States)

    Johnson, L. E.

    1983-01-01

    Simple expedient of heating foam-insulated aluminum alloy tanks prevents corrosion by salt-laden moisture. Relatively-small temperature difference between such tank and surrounding air will ensure life of tank is extended by many years.

  11. Plasma treatment of heat-resistant materials

    International Nuclear Information System (INIS)

    Vlasov, V A; Kosmachev, P V; Skripnikova, N K; Bezukhov, K A

    2015-01-01

    Refractory lining of thermal generating units is exposed to chemical, thermal, and mechanical attacks. The degree of fracture of heat-resistant materials depends on the chemical medium composition, the process temperature and the material porosity. As is known, a shortterm exposure of the surface to low-temperature plasma (LTP) makes possible to create specific coatings that can improve the properties of workpieces. The aim of this work is to produce the protective coating on heat-resistant chamotte products using the LTP technique. Experiments have shown that plasma treatment of chamotte products modifies the surface, and a glass-ceramic coating enriched in mullite is formed providing the improvement of heat resistance. For increasing heat resistance of chamotte refractories, pastes comprising mixtures of Bacor, alumina oxide, and chamot were applied to their surfaces in different ratios. It is proved that the appropriate coating cannot be created if only one of heat-resistant components is used. The required coatings that can be used and recommended for practical applications are obtained only with the introduction of powder chamot. The paste composition of 50% chamot, 25% Bacor, and 25% alumina oxide exposed to plasma treatment, has demonstrated the most uniform surface fusion. (paper)

  12. Heat resistant wire and cable and heat shrinkable tubes

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Keiji [Sumitomo Electric Industries Ltd. (Japan)

    1994-12-31

    Radiation processes have been used in industrial fields (e.g. wire and cable, heat shrinkable tubes) for about 30 years. In Japan, 60 electron beam accelerators were used in R and D, 54 in wire and cable, 24 in tire rubber, 16 in paint curing, 14 in PE foam and 9 accelerators were used in heat shrinkable tubes in 1993. Many properties (e.g. solder resistance, thermal deformation, and solven resistance) of wire and cable are improved by using radiation processes, and many kinds of radiation crosslinked wire and cable are used in the consumer market (TV sets, VTR`s, audio disc players, etc.), automobiles (automobile wire harnesses, fusible link wires, sensor cables etc.), and the industrial market (computer cables, cables for keyboards, coaxial cables, etc.). Another important industrial application of E{beta} radiation process is heat shrinkable tubes. Heat shinkable tubes, heated by a hot gun, shrink 1/2 {approx} 1/3 of their inner diameters. Heat shrinkable tubes are used for covers of distributing line terminals, joint covers of telecommunication lines, protection of fuel pipe lines and so on. In this seminar, actual applications and characteristic properties of radiation crosslinked materials are presented.

  13. Heat resistant wire and cable and heat shrinkable tubes

    International Nuclear Information System (INIS)

    Keiji Ueno

    1994-01-01

    Radiation processes have been used in industrial fields (e.g. wire and cable, heat shrinkable tubes) for about 30 years. In Japan, 60 electron beam accelerators were used in R and D, 54 in wire and cable, 24 in tire rubber, 16 in paint curing, 14 in PE foam and 9 accelerators were used in heat shrinkable tubes in 1993. Many properties (e.g. solder resistance, thermal deformation, and solven resistance) of wire and cable are improved by using radiation processes, and many kinds of radiation crosslinked wire and cable are used in the consumer market (TV sets, VTR's, audio disc players, etc.), automobiles (automobile wire harnesses, fusible link wires, sensor cables etc.), and the industrial market (computer cables, cables for keyboards, coaxial cables, etc.). Another important industrial application of Eβ radiation process is heat shrinkable tubes. Heat shinkable tubes, heated by a hot gun, shrink 1/2 ∼ 1/3 of their inner diameters. Heat shrinkable tubes are used for covers of distributing line terminals, joint covers of telecommunication lines, protection of fuel pipe lines and so on. In this seminar, actual applications and characteristic properties of radiation crosslinked materials are presented

  14. Heat and electricity generating methods

    International Nuclear Information System (INIS)

    Buter, J.

    1977-01-01

    A short synopsis on the actual methods of heating of lodgings and of industrial heat generation is given. Electricity can be generated in steam cycles heated by burning of fossil fuels or by nuclear energy. A valuable contribution to the electricity economy is produced in the hydroelectric power plants. Besides these classical methods, also the different procedures of direct electricity generation are treated: thermoelectric, thermionic, magnetohydrodynamic power sources, solar and fuel cells. (orig.) [de

  15. Heat flow method

    International Nuclear Information System (INIS)

    Chen Yunmei

    1994-01-01

    In this paper we study the heat flow of harmonic maps between two compact Riemannian manifolds. The global existence of the regular solution and the weak solution, as well as the blow up of the weak solution are discussed. (author). 14 refs

  16. Performance of a Heating Block System Designed for Studying the Heat Resistance of Bacteria in Foods

    Science.gov (United States)

    Kou, Xiao-xi; Li, Rui; Hou, Li-xia; Huang, Zhi; Ling, Bo; Wang, Shao-jin

    2016-01-01

    Knowledge of bacteria’s heat resistance is essential for developing effective thermal treatments. Choosing an appropriate test method is important to accurately determine bacteria’s heat resistances. Although being a major factor to influence the thermo-tolerance of bacteria, the heating rate in samples cannot be controlled in water or oil bath methods due to main dependence on sample’s thermal properties. A heating block system (HBS) was designed to regulate the heating rates in liquid, semi-solid and solid foods using a temperature controller. Distilled water, apple juice, mashed potato, almond powder and beef were selected to evaluate the HBS’s performance by experiment and computer simulation. The results showed that the heating rates of 1, 5 and 10 °C/min with final set-point temperatures and holding times could be easily and precisely achieved in five selected food materials. A good agreement in sample central temperature profiles was obtained under various heating rates between experiment and simulation. The experimental and simulated results showed that the HBS could provide a sufficiently uniform heating environment in food samples. The effect of heating rate on bacterial thermal resistance was evaluated with the HBS. The system may hold potential applications for rapid and accurate assessments of bacteria’s thermo-tolerances. PMID:27465120

  17. Heat tracer methods

    Science.gov (United States)

    Healy, Richard W.; Scanlon, Bridget R.

    2010-01-01

    The flow of heat in the subsurface is closely linked to the movement of water (Ingebritsen et al., 2006). As such, heat has been used as a tracer in groundwater studies for more than 100 years (Anderson, 2005). As with chemical and isotopic tracers (Chapter 7), spatial or temporal trends in surface and subsurface temperatures can be used to infer rates of water movement. Temperature can be measured accurately, economically, at high frequencies, and without the need to obtain water samples, facts that make heat an attractive tracer. Temperature measurements made over space and time can be used to infer rates of recharge from a stream or other surface water body (Lapham, 1989; Stonestrom and Constantz, 2003); measurements can also be used to estimate rates of steady drainage through depth intervals within thick unsaturated zones (Constantz et al., 2003; Shan and Bodvarsson, 2004). Several thorough reviews of heat as a tracer in hydrologic studies have recently been published (Constantz et al., 2003; Stonestrom and Constantz, 2003; Anderson, 2005; Blasch et al., 2007; Constantz et al., 2008). This chapter summarizes heat-tracer approaches that have been used to estimate recharge.Some clarification in terminology is presented here to avoid confusion in descriptions of the various approaches that follow. Diffuse recharge is that which occurs more or less uniformly across large areas in response to precipitation, infiltration, and drainage through the unsaturated zone. Estimates of diffuse recharge determined using measured temperatures in the unsaturated zone are referred to as potential recharge because it is possible that not all of the water moving through the unsaturated zone will recharge the aquifer; some may be lost to the atmosphere by evaporation or plant transpiration. Estimated fluxes across confining units in the saturated zone are referred to as interaquifer flow (Chapter 1). Focused recharge is that which occurs directly from a point or line source, such

  18. Effect of smelting method on the austenite grain size and properties of heat-resisting pearlitic steel

    International Nuclear Information System (INIS)

    Balakhovskaya, M.B.; Khusainova, N.A.; Davlyatova, L.N.

    1975-01-01

    Influence of smelting method on austenite grain size and properties of refractory perlite steel were studied. An opportunity was found to increase the steel refractoriness without deteriorating its other properties. The steel 12Kh1MF of electric or common open-hearth smelting was used. The dependence of kinetics of austenite grain growth on the smelting method was studied in the temperature range 950 deg - 1200 deg C with 1 hour exposure. The grain size of austenite in steel is supposedly determined by aluminium nitrides and vanadium carbides. In tests of normalized (kept for 20 minutes at 950-980 deg C) and tempered (kept for 3 hours at 730 deg C) transverse (tangential) pipe cross-section samples the electric steel had higher impact viscosity than the open-hearth metal. At working temperatures (540 deg -580 deg C) the difference in viscosity has its minimum. Viscosity of both steels 12Kh1MF begins to sharply decrease from 20 deg C. However, electric steel has rather high viscosity even at - 40 deg C, while the open-hearth one becomes brittle as early as at - 20 deg C. Long-term strength tests at 580 deg C under stresses 10-14 kG/mm 2 show that the coarse-grain steel is more refractory, i.e. time till fracture of open-hearth steel samples is twice as long as that of electric steel samples

  19. Effect of smelting method on the austenite grain size and properties of heat-resisting pearlitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Balakhovskaya, M B; Khusainova, N A; Davlyatova, L N [Vsesoyuznyj Nauchno-Issledovatel' skij Teplotekhnicheskij Inst., Moscow (USSR)

    1975-12-01

    Influence of smelting method on austenite grain size and properties of refractory perlite steel were studied. An opportunity was found to increase the steel refractoriness without deteriorating its other properties. The steel 12Kh1MF of electric or common open-hearth smelting was used. The dependence of kinetics of austenite grain growth on the smelting method was studied in the temperature range 950 deg - 1200 deg C with 1 hour exposure. The grain size of austenite in steel is supposedly determined by aluminium nitrides and vanadium carbides. In tests of normalized (kept for 20 minutes at 950-980 deg C) and tempered (kept for 3 hours at 730 deg C) transverse (tangential) pipe cross-section samples the electric steel had higher impact viscosity than the open-hearth metal. At working temperatures (540 deg -580 deg C) the difference in viscosity has its minimum. Viscosity of both steels 12Kh1MF begins to sharply decrease from 20 deg C. However, electric steel has rather high viscosity even at /sup -/40 deg C, while the open-hearth one becomes brittle as early as at /sup -/20 deg C. Long-term strength tests at 580 deg C under stresses 10-14 kG/mm/sup 2/ show that the coarse-grain steel is more refractory, i.e. time till fracture of open-hearth steel samples is twice as long as that of electric steel samples.

  20. Development of heat resistant ion exchange resin. First Report

    International Nuclear Information System (INIS)

    Onozuka, Teruo; Shindo, Manabu

    1995-01-01

    In nuclear power stations, as a means of maintaining the soundness of nuclear reactors, the cleaning of reactor cooling water has been carried out. But as for the ion exchange resin which is used as the cleaning agent in the filtrating and desalting facility in reactor water cleaning system, since the heat resistance is low, high temperature reactor water is cooled once and cleaned, therefore large heat loss occurs. If the cleaning can be done at higher temperature, the reduction of heat loss and compact cleaning facilities become possible. In this study, a new ion exchange resin having superior heat resistance has been developed, and the results of the test of evaluating the performance of the developed ion exchange resin are reported. The heat loss in reactor water cleaning system, the heat deterioration of conventional ion exchange resin, and the development of the anion exchange resin of alkyl spacer type are described. The outline of the performance evaluation test, the experimental method, and the results of the heat resistance, ion exchange characteristics and so on of C4 resin are reported. The with standable temperature of the developed anion exchange resin was estimated as 80 - 90degC. The ion exchange performance at 95degC of this resin did not change from that at low temperature in chloride ions and silica, and was equivalent to that of existing anion exchange resin. (K.I.)

  1. Development of heat resistant ion exchange resin. First Report

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, Teruo; Shindo, Manabu [Tohoku Electric Power Co., Inc., Sendai (Japan)

    1995-01-01

    In nuclear power stations, as a means of maintaining the soundness of nuclear reactors, the cleaning of reactor cooling water has been carried out. But as for the ion exchange resin which is used as the cleaning agent in the filtrating and desalting facility in reactor water cleaning system, since the heat resistance is low, high temperature reactor water is cooled once and cleaned, therefore large heat loss occurs. If the cleaning can be done at higher temperature, the reduction of heat loss and compact cleaning facilities become possible. In this study, a new ion exchange resin having superior heat resistance has been developed, and the results of the test of evaluating the performance of the developed ion exchange resin are reported. The heat loss in reactor water cleaning system, the heat deterioration of conventional ion exchange resin, and the development of the anion exchange resin of alkyl spacer type are described. The outline of the performance evaluation test, the experimental method, and the results of the heat resistance, ion exchange characteristics and so on of C4 resin are reported. The with standable temperature of the developed anion exchange resin was estimated as 80 - 90degC. The ion exchange performance at 95degC of this resin did not change from that at low temperature in chloride ions and silica, and was equivalent to that of existing anion exchange resin. (K.I.).

  2. Resistively heated shape memory polymer device

    Energy Technology Data Exchange (ETDEWEB)

    Marion, III, John E.; Bearinger, Jane P.; Wilson, Thomas S.; Maitland, Duncan J.

    2017-09-05

    A resistively heated shape memory polymer device is made by providing a rod, sheet or substrate that includes a resistive medium. The rod, sheet or substrate is coated with a first shape memory polymer providing a coated intermediate unit. The coated intermediate unit is in turn coated with a conductive material providing a second intermediate unit. The second coated intermediate unit is in turn coated with an outer shape memory polymer. The rod, sheet or substrate is exposed and an electrical lead is attached to the rod, sheet or substrate. The conductive material is exposed and an electrical lead is attached to the conductive material.

  3. Resistively heated shape memory polymer device

    Energy Technology Data Exchange (ETDEWEB)

    Marion, III, John E.; Bearinger, Jane P.; Wilson, Thomas S.; Maitland, Duncan J.

    2016-10-25

    A resistively heated shape memory polymer device is made by providing a rod, sheet or substrate that includes a resistive medium. The rod, sheet or substrate is coated with a first shape memory polymer providing a coated intermediate unit. The coated intermediate unit is in turn coated with a conductive material providing a second intermediate unit. The second coated intermediate unit is in turn coated with an outer shape memory polymer. The rod, sheet or substrate is exposed and an electrical lead is attached to the rod, sheet or substrate. The conductive material is exposed and an electrical lead is attached to the conductive material.

  4. Adriamycin resistance, heat resistance and radiation response in Chinese hamster fibroblasts

    International Nuclear Information System (INIS)

    Wallner, K.; Li, G.

    1985-01-01

    Previous investigators have demonstrated synergistic interaction between hyperthermia and radiation or Adriamycin (ADR), using cell lines that are sensitive to heat or ADR alone. The authors investigated the effect of heat, radiation or ADR on Chinese hamster fibroblasts (HA-1), their heat resistant variants and their ADR resistant variants. Heat for ADR resistance did not confer cross resistance to radiation. Cells resistant to heat did show cross resistance to ADR. While cells selected for ADR resistance were not cross resistant to heat, they did not exhibit drug potentiation by hyperthermia, characteristic of ADR sensitive cells. Cytofluorometric measurement showed decreased ADR uptake in both heat and ADR resistant cells. The possibility of cross resistance between heat and ADR should be considered when designing combined modality trials

  5. Effect of heating method on stress-rupture life

    Science.gov (United States)

    Bizon, P. T.; Calfo, F. D.

    1977-01-01

    The effect of radiant(furnace), resistance(electric current), burner(hot gas stream), and a combination of resistance and burner heating on intermediate time (100 to 300 hr) stress-rupture life and reduction of area was evaluated. All heating methods were studied using the nickel-based alloy Udimet 700 while all but burner heating were evaluated with the cobalt-based alloy Mar-M 509. Limited test results of eight other superalloys were also included in this study. Resistance heated specimens had about 20 to 30 percent of the stress-rupture life of radiant heated specimens. The limited burner heating data showed about a 50 percent life reduction as compared to the radiant heated tests. A metallurgical examination gave no explanation for these reductions.

  6. Genetic determinants of heat resistance in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Ryan eMercer

    2015-09-01

    Full Text Available Escherichia coli AW1.7 is a heat resistant food isolate and the occurrence of pathogenic strains with comparable heat resistance may pose a risk to food safety. To identify the genetic determinants of heat resistance, 29 strains of E. coli that differed in their of heat resistance were analyzed by comparative genomics. Strains were classified as highly heat resistant strains, exhibiting a D60-value of more than 6 min; moderately heat resistant strains, exhibiting a D60-value of more than 1 min; or as heat sensitive. A ~14 kb genomic island containing 16 predicted open reading frames encoding putative heat shock proteins and proteases was identified only in highly heat resistant strains. The genomic island was termed the locus of heat resistance (LHR. This putative operon is flanked by mobile elements and possesses >99% sequence identity to genomic islands contributing to heat resistance in Cronobacter sakazakii and Klebsiella pneumoniae. An additional 41 LHR sequences with >87% sequence identity were identified in 11 different species of β- and γ-proteobacteria. Cloning of the full length LHR conferred high heat resistance to the heat sensitive E. coli AW1.7ΔpHR1 and DH5α. The presence of the LHR correlates perfectly to heat resistance in several species of Enterobacteriaceae and occurs at a frequency of 2% of all E. coli genomes, including pathogenic strains. This study suggests the LHR has been laterally exchanged among the β- and γ-proteobacteria and is a reliable indicator of high heat resistance in E. coli.

  7. Heat exchanger device and method for heat removal or transfer

    Science.gov (United States)

    Koplow, Jeffrey P

    2013-12-10

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  8. Determination and Application of Comprehensive Specific Frictional Resistance in Heating Engineering

    Directory of Open Access Journals (Sweden)

    Yanan Tian

    2018-01-01

    Full Text Available In this study, we analyze the deficiencies of specific frictional resistance in heating engineering. Based on economic specific frictional resistance, we put forward the concept of comprehensive specific frictional resistance, which considers the multiple factors of technology, economy, regulation modes, pipe segment differences, and medium pressure. Then, we establish a mathematical model of a heating network across its lifespan in order to develop a method for determining the comprehensive specific frictional resistance. Relevant conclusions can be drawn from the results. As an application, we have planned the heating engineering for Yangyuan County in China, which demonstrates the feasibility and superiority of the method.

  9. Self-heating, gamma heating and heat loss effects on resistance temperature detector (RTD) accuracy

    International Nuclear Information System (INIS)

    Qian, T.; Hinds, H.W.; Tonner, P.

    1997-01-01

    Resistance temperature detectors (RTDs) are extensively used in CANDU nuclear power stations for measuring various process and equipment temperatures. Accuracy of measurement is an important performance parameter of RTDs and has great impact on the thermal power efficiency and safety of the plant. There are a number of factors that contribute to some extent to RTD measurement error. Self-heating, gamma heating and the heat-loss throughout conduction of the thermowell are three of these factors. The degree to which these three affect accuracy of RTDs used for the measurement of reactor inlet header temperature (RIHT) has been analyzed and is presented in this paper. (author)

  10. Heat-resistant hydrophobic-oleophobic coatings

    OpenAIRE

    Uyanik, Mehmet; Arpac, Ertugrul; Schmidt, Helmut K.; Akarsu, Murat; Sayilkan, Funda; Sayilkan, Hikmet

    2006-01-01

    Thermally and chemically durable hydrophobic oleophobic coatings, containing different ceramic particles such as SiO2, SiC, Al 2O3, which can be alternative instead of Teflon, have been developed and applied on the aluminum substrates by spin-coating method. Polyimides, which are high-thermal resistant heteroaromatic polymers, were synthesized, and fluor oligomers were added to these polymers to obtain hydrophobic-oleophobic properties. After coating, Al surface was subjected to Taber-abrasio...

  11. Evaluation of Heat Capacity and Resistance to Cyclic Oxidation of Nickel Superalloys

    Directory of Open Access Journals (Sweden)

    Przeliorz R.

    2014-08-01

    Full Text Available Paper presents the results of evaluation of heat resistance and specific heat capacity of MAR-M-200, MAR-M-247 and Rene 80 nickel superalloys. Heat resistance was evaluated using cyclic method. Every cycle included heating in 1100°C for 23 hours and cooling for 1 hour in air. Microstructure of the scale was observed using electron microscope. Specific heat capacity was measured using DSC calorimeter. It was found that under conditions of cyclically changing temperature alloy MAR-M-247 exhibits highest heat resistance. Formed oxide scale is heterophasic mixture of alloying elements, under which an internal oxidation zone was present. MAR-M-200 alloy has higher specific heat capacity compared to MAR-M-247. For tested alloys in the temperature range from 550°C to 800°C precipitation processes (γ′, γ″ are probably occurring, resulting in a sudden increase in the observed heat capacity.

  12. Entropy resistance analyses of a two-stream parallel flow heat exchanger with viscous heating

    International Nuclear Information System (INIS)

    Cheng Xue-Tao; Liang Xin-Gang

    2013-01-01

    Heat exchangers are widely used in industry, and analyses and optimizations of the performance of heat exchangers are important topics. In this paper, we define the concept of entropy resistance based on the entropy generation analyses of a one-dimensional heat transfer process. With this concept, a two-stream parallel flow heat exchanger with viscous heating is analyzed and discussed. It is found that the minimization of entropy resistance always leads to the maximum heat transfer rate for the discussed two-stream parallel flow heat exchanger, while the minimizations of entropy generation rate, entropy generation numbers, and revised entropy generation number do not always. (general)

  13. Studying microstructure of heat resistant steel deoxidized by barium ferrosilicon

    Directory of Open Access Journals (Sweden)

    A. Z. Issagulov

    2016-07-01

    Full Text Available The paper examined the nature and distribution of non-metallic inclusions in the heat-resistant steel 12H1MF (0,12 % С, 1 % Сr, 0,5 - 0,6 Mo, 0,5 % V, ferrosilicobarim. As a reference, used by steel, deoxidized silicon. Melting was carried out in a laboratory, research-metallic inclusions, their shape and distribution, pollution index were studied according to conventional methods. Studies have shown that ferrosilicobarim deoxidation in an amount of 0,1 - 0,2 %, reduce the overall pollution index of non-metallic inclusions and change the nature of their distribution.

  14. Induction and direct resistance heating theory and numerical modeling

    CERN Document Server

    Lupi, Sergio; Aliferov, Aleksandr

    2015-01-01

    This book offers broad, detailed coverage of theoretical developments in induction and direct resistance heating and presents new material on the solution of problems in the application of such heating. The physical basis of induction and conduction heating processes is explained, and electromagnetic phenomena in direct resistance and induction heating of flat workpieces and cylindrical bodies are examined in depth. The calculation of electrical and energetic characteristics of induction and conduction heating systems is then thoroughly reviewed. The final two chapters consider analytical solutions and numerical modeling of problems in the application of induction and direct resistance heating, providing industrial engineers with the knowledge needed in order to use numerical tools in the modern design of installations. Other engineers, scientists, and technologists will find the book to be an invaluable reference that will assist in the efficient utilization of electrical energy.

  15. Design of heat exchangers by numerical methods

    International Nuclear Information System (INIS)

    Konuk, A.A.

    1981-01-01

    Differential equations describing the heat tranfer in shell - and tube heat exchangers are derived and solved numerically. The method of ΔT sub(lm) is compared with the proposed method in cases where the specific heat at constant pressure, Cp and the overall heat transfer coefficient, U, vary with temperature. The error of the method of ΔT sub (lm) for the computation of the exchanger lenght is less than + 10%. However, the numerical method, being more accurate and at the same time easy to use and economical, is recommended for the design of shell-and-tube heat exchangers. (Author) [pt

  16. The Heating Curve Adjustment Method

    NARCIS (Netherlands)

    Kornaat, W.; Peitsman, H.C.

    1995-01-01

    In apartment buildings with a collective heating system usually a weather compensator is used for controlling the heat delivery to the various apartments. With this weather compensator the supply water temperature to the apartments is regulated depending on the outside air temperature. With

  17. Relaxation resistance of heat resisting alloys with cobalt

    International Nuclear Information System (INIS)

    Borzdyka, A.M.

    1977-01-01

    Relaxation resistance of refractory nickel-chromium alloys containing 5 to 14 % cobalt is under study. The tests involve the use of circular samples at 800 deg to 850 deg C. It is shown that an alloy containing 14% cobalt possesses the best relaxation resistance exceeding that of nickel-chromium alloys without any cobalt by a factor of 1.5 to 2. The relaxation resistance of an alloy with 5% cobalt can be increased by hardening at repeated loading

  18. Heat-resistant fungi of importance to the food and beverage industry.

    Science.gov (United States)

    Tournas, V

    1994-01-01

    Spoilage of pasteurized and canned fruit and fruit products caused by heat-resistant molds have been reported repeatedly in recent years. Species most commonly implicated in fruit and fruit product disintegration are Byssochlamys fulva, Byssochlamys nivea, Neosartorya fischeri, Talaromyces flavus, and Eupenicillium brefeldianum. These organisms are saprophytic rather than parasitic and usually contaminate fruits on or near the ground. They can survive heat treatments used for fruit processing and can grow and spoil the products during storage at room temperature, which results in great economic losses. Mold heat resistance is attributed to the formation of sexual spores, ascospores. Ascospores have a wide range of heat resistance, depending on species, strain, age of organism, heating medium, pH, presence of sugars, fats, and acids in heating medium, growth conditions, etc. The mechanism(s) of thermoresistance are not clear; probably some very stable compound(s) critical to germination and outgrowth are present in the heat-resistant ascospores. Besides spoilage, the heat-resistant molds produce a number of toxic secondary metabolites, such as byssotoxin A; byssochlamic acid; the carcinogen, patulin, the tremorgenic substances, fumitremorgin A and C, and verruculogen; fischerin, which caused fatal peritonitis in mice; and eupenifeldin, a compound possessing cytotoxicity as well as in vivo antitumor activity. Growth of heat-resistant fungi can be controlled by lowering the water activity, adding sulfur dioxide, sorbate, or benzoate; washing of fruits in hypochlorite solution before heat treatment reduces the number of ascospores and makes the heat destruction more successful. More research is needed to elucidate the mechanism(s) of thermoresistance and develop new methods for the complete inactivation of resistant ascospores.

  19. Heat- and radiation-resistant scintillator for electron microscopes

    International Nuclear Information System (INIS)

    Kosov, A.V.; Petrov, S.A.; Puzyr', A.P.; Chetvergov, N.A.

    1987-01-01

    The use of a scintillator consisting of a single crystal of bismuth orthogermanate, which has high heat and radiation resistance, in REM-100, REM-200, and REM-100U electron microscopes is described. A study of the heat and radiation stabilities of single crystals of bismuth orthogermanate (Bi 4 Ge 3 O 12 ) has shown that they withstood multiple electron-beam heating redness (T ∼ 800 0 C) without changes in their properties

  20. The log mean heat transfer rate method of heat exchanger considering the influence of heat radiation

    International Nuclear Information System (INIS)

    Wong, K.-L.; Ke, M.-T.; Ku, S.-S.

    2009-01-01

    The log mean temperature difference (LMTD) method is conventionally used to calculate the total heat transfer rate of heat exchangers. Because the heat radiation equation contains the 4th order exponential of temperature which is very complicate in calculations, thus LMTD method neglects the influence of heat radiation. From the recent investigation of a circular duct in some practical situations, it is found that even in the situation of the temperature difference between outer duct surface and surrounding is low to 1 deg. C, the heat radiation effect can not be ignored in the situations of lower ambient convective heat coefficient and greater surface emissivities. In this investigation, the log mean heat transfer rate (LMHTR) method which considering the influence of heat radiation, is developed to calculate the total heat transfer rate of heat exchangers.

  1. 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.)

  2. A novel design method for ground source heat pump

    Directory of Open Access Journals (Sweden)

    Dong Xing-Jie

    2014-01-01

    Full Text Available This paper proposes a novel design method for ground source heat pump. The ground source heat pump operation is controllable by using several parameters, such as the total meters of buried pipe, the space between wells, the thermal properties of soil, thermal resistance of the well, the initial temperature of soil, and annual dynamic load. By studying the effect of well number and well space, we conclude that with the increase of the well number, the inlet and outlet water temperatures decrease in summer and increase in winter, which enhance the efficiency of ground source heat pump. The well space slightly affects the water temperatures, but it affects the soil temperature to some extent. Also the ground source heat pump operations matching with cooling tower are investigated to achieve the thermal balance. This method greatly facilitates ground source heat pump design.

  3. Magnus: A New Resistive MHD Code with Heat Flow Terms

    Science.gov (United States)

    Navarro, Anamaría; Lora-Clavijo, F. D.; González, Guillermo A.

    2017-07-01

    We present a new magnetohydrodynamic (MHD) code for the simulation of wave propagation in the solar atmosphere, under the effects of electrical resistivity—but not dominant—and heat transference in a uniform 3D grid. The code is based on the finite-volume method combined with the HLLE and HLLC approximate Riemann solvers, which use different slope limiters like MINMOD, MC, and WENO5. In order to control the growth of the divergence of the magnetic field, due to numerical errors, we apply the Flux Constrained Transport method, which is described in detail to understand how the resistive terms are included in the algorithm. In our results, it is verified that this method preserves the divergence of the magnetic fields within the machine round-off error (˜ 1× {10}-12). For the validation of the accuracy and efficiency of the schemes implemented in the code, we present some numerical tests in 1D and 2D for the ideal MHD. Later, we show one test for the resistivity in a magnetic reconnection process and one for the thermal conduction, where the temperature is advected by the magnetic field lines. Moreover, we display two numerical problems associated with the MHD wave propagation. The first one corresponds to a 3D evolution of a vertical velocity pulse at the photosphere-transition-corona region, while the second one consists of a 2D simulation of a transverse velocity pulse in a coronal loop.

  4. Comparison of Direct Solar Energy to Resistance Heating for Carbothermal Reduction of Regolith

    Science.gov (United States)

    Muscatello, Anthony C.; Gustafson, Robert J.

    2011-01-01

    A comparison of two methods of delivering thermal energy to regolith for the carbo thermal reduction process has been performed. The comparison concludes that electrical resistance heating is superior to direct solar energy via solar concentrators for the following reasons: (1) the resistance heating method can process approximately 12 times as much regolith using the same amount of thermal energy as the direct solar energy method because of superior thermal insulation; (2) the resistance heating method is more adaptable to nearer-term robotic exploration precursor missions because it does not require a solar concentrator system; (3) crucible-based methods are more easily adapted to separation of iron metal and glass by-products than direct solar energy because the melt can be poured directly after processing instead of being remelted; and (4) even with projected improvements in the mass of solar concentrators, projected photovoltaic system masses are expected to be even lower.

  5. Resistive Heating and Ion Drag in Saturn's Thermosphere

    Science.gov (United States)

    Vriesema, Jess William; Koskinen, Tommi; Yelle, Roger V.

    2017-10-01

    One of the most puzzling observations of the jovian planets is that the thermospheres of Jupiter, Saturn, Uranus and Neptune are all several times hotter than solar heating can account for (Strobel and Smith 1973; Yelle and Miller 2004; Muller-Wodarg et al. 2006). On Saturn, resistive heating appears sufficient to explain these temperatures in auroral regions, but the particular mechanism(s) responsible for heating the lower latitudes remains unclear. The most commonly proposed heating mechanisms are breaking gravity waves and auroral heating at the poles followed by redistribution of energy to mid-and low latitudes. Both of these energy sources are potentially important but also come with significant problems. Wave heating would have to be continuous and global to produce consistently elevated temperatures and the strong Coriolis forces coupled with polar ion drag appear to hinder redistribution of auroral energy (see Strobel et al. 2016 for review). Here we explore an alternative: wind-driven electrodynamics that can alter circulation and produce substantial heating outside of the auroral region. Smith (2013) showed this in-situ mechanism to be potentially significant in Jupiter’s thermosphere. We present new results from an axisymmetric, steady-state model that calculates resistive (Joule) heating rates through rigorous solutions of the electrodynamic equations for the coupled neutral atmosphere and ionosphere of Saturn. At present, we assume a dipole magnetic field and neglect any contributions from the magnetosphere. We use ion mixing ratios from the model of Kim et al. (2014) and the observed temperature-pressure profile from Koskinen et al. (2015) to calculate the generalized conductivity tensor as described by Koskinen et al. (2014). We calculate the current density under the assumption that it has no divergence and use it to calculate the resistive heating rates and ion drag. Our results suggest that resistive heating and ion drag at low latitudes likely

  6. Iron aluminide useful as electrical resistance heating elements

    Science.gov (United States)

    Sikka, Vinod K.; Deevi, Seetharama C.; Fleischhauer, Grier S.; Hajaligol, Mohammad R.; Lilly, Jr., A. Clifton

    1997-01-01

    The invention relates generally to aluminum containing iron-base alloys useful as electrical resistance heating elements. The aluminum containing iron-base alloys have improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The alloy has an entirely ferritic microstructure which is free of austenite and includes, in weight %, over 4% Al, .ltoreq.1% Cr and either .gtoreq.0.05% Zr or ZrO.sub.2 stringers extending perpendicular to an exposed surface of the heating element or .gtoreq.0.1% oxide dispersoid particles. The alloy can contain 14-32% Al, .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Zr, .ltoreq.1% C, .ltoreq.0.1% B, .ltoreq.30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, .ltoreq.1% oxygen, .ltoreq.3% Cu, balance Fe.

  7. Iron aluminide useful as electrical resistance heating elements

    Science.gov (United States)

    Sikka, V.K.; Deevi, S.C.; Fleischhauer, G.S.; Hajaligol, M.R.; Lilly, A.C. Jr.

    1997-04-15

    The invention relates generally to aluminum containing iron-base alloys useful as electrical resistance heating elements. The aluminum containing iron-base alloys have improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The alloy has an entirely ferritic microstructure which is free of austenite and includes, in weight %, over 4% Al, {=}0.05% Zr or ZrO{sub 2} stringers extending perpendicular to an exposed surface of the heating element or {>=}0.1% oxide dispersoid particles. The alloy can contain 14-32% Al, {<=}2% Ti, {<=}2% Mo, {<=}1% Zr, {<=}1% C, {<=}0.1% B, {<=}30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, {<=}1% rare earth metal, {<=}1% oxygen, {<=}3% Cu, balance Fe. 64 figs.

  8. Diversity Assessment of Heat Resistance of Listeria monocytogenes Strains in a Continuous-Flow Heating System

    NARCIS (Netherlands)

    Veen, van der S.; Wagendorp, A.; Abee, T.; Wells-Bennik, M.H.J.

    2009-01-01

    Listeria monocytogenes is a foodborne pathogen that has the ability to survive relatively high temperatures compared with other nonsporulating foodborne pathogens. This study was performed to determine whether L. monocytogenes strains with relatively high heat resistances are adequately inactivated

  9. Thermal resistance of a convectively cooled plate with applied heat flux and variable internal heat generation

    International Nuclear Information System (INIS)

    Venkataraman, N.S.; Cardoso, H.P.; Oliveira Filho, O.B. de

    1981-01-01

    The conductive heat transfer in a rectangular plate with nonuniform internal heat generation, with one end convectively cooled and a part of the opposite end subjected to external heat flux is considered. The remaining part of this end as well as the other two sides are thermally insulated. The governing differential equation is solved by a finite difference scheme. The variation of the thermal resistance with Biot modulus, the plate geometry, the internal heat generation parameter and the type of profile of internal heat generation is discussed. (author) [pt

  10. Numerical methods in simulation of resistance welding

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Martins, Paulo A.F.; Zhang, Wenqi

    2015-01-01

    Finite element simulation of resistance welding requires coupling betweenmechanical, thermal and electrical models. This paper presents the numerical models and theircouplings that are utilized in the computer program SORPAS. A mechanical model based onthe irreducible flow formulation is utilized...... a resistance welding point of view, the most essential coupling between the above mentioned models is the heat generation by electrical current due to Joule heating. The interaction between multiple objects is anothercritical feature of the numerical simulation of resistance welding because it influences...... thecontact area and the distribution of contact pressure. The numerical simulation of resistancewelding is illustrated by a spot welding example that includes subsequent tensile shear testing...

  11. In vitro induction of variability through radiation for late blight resistance and heat tolerance in potato

    International Nuclear Information System (INIS)

    Gosal, S.S.; Das, A.; Gopal, J.; Minocha, J.L.; Chopra, H.R.; Dhaliwal, H.S.

    2001-01-01

    In vitro cultured shoots of potato, cvs. 'Kufri Jyoti' and 'Kufri Chandramukhi', were irradiated with 20 and 40 Gy gamma rays. Microtubers, obtained from MIV3 shoots multiplied in vitro, were planted in pots. The resulting plants were screened for resistance to late blight, using detached leaf method. In 'Kufri Chandramukhi', 42% plants and in 'Kufri Jyoti' 36% plants, obtained from 40 Gy treatment, showed resistance to late blight. The frequency of resistant plants was lower from 20 Gy treatment. The progenies of putatively resistant plants were grown in field, and inoculated with sporangial inoculum of late blight fungus. The field grown progeny segregated for disease resistance, and approximately 56% plants showed resistance. During the next propagation, the frequency of resistant plants increased to 72%. For developing heat tolerance, microtubers obtained from 20 and 40 Gy treatments and in vitro multiplied M 1 V 3 shoots were cultured at high temperature of 28C. In both varieties, the number of the microtubers per plant was highly reduced and the resulting microtubers had distorted shape but showed better germination (62%), even in early sowing at relatively higher temperature. Of the two radiation doses, the higher dose of 40 Gy gave better results in both the varieties. Heat tolerance was also assessed from chlorophyll persistence. The progenies from putative heat-tolerant plants were tested in field by planting at higher temperature in two subsequent generations. The heat tolerant plants segregated in each generation, but the frequency of heat-tolerant plants increased. (author)

  12. Propagation of resist heating mask error to wafer level

    Science.gov (United States)

    Babin, S. V.; Karklin, Linard

    2006-10-01

    As technology is approaching 45 nm and below the IC industry is experiencing a severe product yield hit due to rapidly shrinking process windows and unavoidable manufacturing process variations. Current EDA tools are unable by their nature to deliver optimized and process-centered designs that call for 'post design' localized layout optimization DFM tools. To evaluate the impact of different manufacturing process variations on final product it is important to trace and evaluate all errors through design to manufacturing flow. Photo mask is one of the critical parts of this flow, and special attention should be paid to photo mask manufacturing process and especially to mask tight CD control. Electron beam lithography (EBL) is a major technique which is used for fabrication of high-end photo masks. During the writing process, resist heating is one of the sources for mask CD variations. Electron energy is released in the mask body mainly as heat, leading to significant temperature fluctuations in local areas. The temperature fluctuations cause changes in resist sensitivity, which in turn leads to CD variations. These CD variations depend on mask writing speed, order of exposure, pattern density and its distribution. Recent measurements revealed up to 45 nm CD variation on the mask when using ZEP resist. The resist heating problem with CAR resists is significantly smaller compared to other types of resists. This is partially due to higher resist sensitivity and the lower exposure dose required. However, there is no data yet showing CD errors on the wafer induced by CAR resist heating on the mask. This effect can be amplified by high MEEF values and should be carefully evaluated at 45nm and below technology nodes where tight CD control is required. In this paper, we simulated CD variation on the mask due to resist heating; then a mask pattern with the heating error was transferred onto the wafer. So, a CD error on the wafer was evaluated subject to only one term of the

  13. Argon-arc welding of heat resisting aluminium alloys

    International Nuclear Information System (INIS)

    Ryazantsev, V.I.; Fedoseev, V.A.

    1997-01-01

    Welding of aluminium heat resisting alloys of the Al-Cu-Mg system is studied. The hot-shortness of heat-resistant alloys M40, 1150 and 1151 are at the level of aluminium alloys 1201 and by 2-3 times lower as compared to the aluminium alloy AMg6. The M40, 1150 and 1151 alloys have unquestionable advantages against other know aluminium alloys only at temperatures of welded structures operation, beginning with 150-2000 deg C and especially at 250 deg C

  14. Study on the heat-resistant EB curing composites

    International Nuclear Information System (INIS)

    Bao Jianwen; Li Yang; Li Fengmei

    2000-01-01

    There are many advantages in the EB-curing process of composites. Heat-resistant EB-curing composites could substitute for polyimide composites used in aeronautical engine. The effects of catalyst and dose on the cured resin were investigated. The heat-resistance of the resin cured by EB was evaluated by dynamic mechanical thermal analysis (DMTA). The experiment result shows that the mechanical property of the composites cured by EB could meet the needs of the aeronautical engine in 250degC. (author)

  15. Heterogeneity of heat-resistant proteases from milk Pseudomonas species.

    Science.gov (United States)

    Marchand, Sophie; Vandriesche, Gonzalez; Coorevits, An; Coudijzer, Katleen; De Jonghe, Valerie; Dewettinck, Koen; De Vos, Paul; Devreese, Bart; Heyndrickx, Marc; De Block, Jan

    2009-07-31

    Pseudomonas fragi, Pseudomonas lundensis and members of the Pseudomonas fluorescens group may spoil Ultra High Temperature (UHT) treated milk and dairy products, due to the production of heat-stable proteases in the cold chain of raw milk. Since the aprX gene codes for a heat-resistant protease in P. fluorescens, the presence of this gene has also been investigated in other members of the genus. For this purpose an aprX-screening PCR test has been developed. Twenty-nine representatives of important milk Pseudomonas species and thirty-five reference strains were screened. In 42 out of 55 investigated Pseudomonas strains, the aprX gene was detected, which proves the potential of the aprX-PCR test as a screening tool for potentially proteolytic Pseudomonas strains in milk samples. An extensive study of the obtained aprX-sequences on the DNA and the amino acid level, however, revealed a large heterogeneity within the investigated milk isolates. Although this heterogeneity sets limitations to a general detection method for all proteolytic Pseudomonas strains in milk, it offers a great potential for the development of a multiplex PCR screening test targeting individual aprX-genes. Furthermore, our data illustrated the potential use of the aprX gene as a taxonomic marker, which may help in resolving the current taxonomic deadlock in the P. fluorescens group.

  16. Method for Calculation of Steam-Compression Heat Transformers

    Directory of Open Access Journals (Sweden)

    S. V. Zditovetckaya

    2012-01-01

    Full Text Available The paper considers a method for joint numerical analysis of cycle parameters and heatex-change equipment of steam-compression heat transformer contour that takes into account a non-stationary operational mode and irreversible losses in devices and pipeline contour. The method has been realized in the form of the software package and can be used while making design or selection of a heat transformer with due account of a coolant and actual equipment being included in its structure.The paper presents investigation results revealing influence of pressure loss in an evaporator and a condenser from the side of the coolant caused by a friction and local resistance on power efficiency of the heat transformer which is operating in the mode of refrigerating and heating installation and a thermal pump. Actually obtained operational parameters of the thermal pump in the nominal and off-design operatinal modes depend on the structure of the concrete contour equipment.

  17. Methods for tube attachment in a heat exchange equipment

    International Nuclear Information System (INIS)

    Shilin, O.V.; Vasil'ev, V.B.

    1984-01-01

    Two main ways of attaching tubes to tube panels in heat exchange equipment are analyzed: expanding and pulse method (by explosion, for instance). Labour-consumption and cost price for the fastening of brass, perlitic and corrosion-resistant tubes for both of the methods are presented. The extent of fitting out with equipment for tube fixing and ways of testing the joints for attachment are evaluated. Measures for improving the joint quality and introduction of the advanced technology are suggested

  18. Oxidation protection of austenite steels by heat-resisting glass-and-enamel coatings

    International Nuclear Information System (INIS)

    Lobzhanidze, V.N.; Korchagin, V.S.

    1977-01-01

    The use of glass-enamel coatings for corrosion protection of austenitic steels during heat treatment has been investigated. When working out the composition of the protective coating, the method of mathematical planning of experiments has been used. It is shown that the coating under investigation can best be used in heat treatment of items with a prolonged time of heating to 1050 deg C (18-20 hr). The savings resulting from the introduction of the heat-resistant glass-enamel coating exceed 30000 roubles

  19. Method of Heating a Foam-Based Catalyst Bed

    Science.gov (United States)

    Fortini, Arthur J.; Williams, Brian E.; McNeal, Shawn R.

    2009-01-01

    A method of heating a foam-based catalyst bed has been developed using silicon carbide as the catalyst support due to its readily accessible, high surface area that is oxidation-resistant and is electrically conductive. The foam support may be resistively heated by passing an electric current through it. This allows the catalyst bed to be heated directly, requiring less power to reach the desired temperature more quickly. Designed for heterogeneous catalysis, the method can be used by the petrochemical, chemical processing, and power-generating industries, as well as automotive catalytic converters. Catalyst beds must be heated to a light-off temperature before they catalyze the desired reactions. This typically is done by heating the assembly that contains the catalyst bed, which results in much of the power being wasted and/or lost to the surrounding environment. The catalyst bed is heated indirectly, thus requiring excessive power. With the electrically heated catalyst bed, virtually all of the power is used to heat the support, and only a small fraction is lost to the surroundings. Although the light-off temperature of most catalysts is only a few hundred degrees Celsius, the electrically heated foam is able to achieve temperatures of 1,200 C. Lower temperatures are achievable by supplying less electrical power to the foam. Furthermore, because of the foam s open-cell structure, the catalyst can be applied either directly to the foam ligaments or in the form of a catalyst- containing washcoat. This innovation would be very useful for heterogeneous catalysis where elevated temperatures are needed to drive the reaction.

  20. The lumped heat capacity method applied to target heating

    OpenAIRE

    Rickards, J.

    2013-01-01

    The temperature of metal samples was measured while they were bombarded by the beam from the a particle accelerator. The evolution of the temperature with time can be explained using the lumped heat capacity method of heat transfer. A strong dependence on the type of mounting was found. Se midió la temperatura de muestras metálicas al ser bombardeadas por el haz de iones del Acelerador Pelletron del Instituto de Física. La evolución de la temperatura con el tiempo se puede explicar usando ...

  1. 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

  2. Fast temperature programming in gas chromatography using resistive heating

    NARCIS (Netherlands)

    Dallüge, J.; Ou-Aissa, R.; Vreuls, J.J.; Brinkman, U.A.T.; Veraart, J.R.

    1999-01-01

    The features of a resistive-heated capillary column for fast temperature-programmed gas chromatography (GC) have been evaluated. Experiments were carried out using a commercial available EZ Flash GC, an assembly which can be used to upgrade existing gas chromatographs. The capillary column is placed

  3. Signal mediators at induction of heat resistance of wheat plantlets by short-term heating

    Directory of Open Access Journals (Sweden)

    Yu. V. Karpets

    2015-12-01

    Full Text Available The effects of functional interplay of calcium ions, reactive oxygen species (ROS and nitric oxide (NO in the cells of wheat plantlets roots (Triticum aestivum L. at the induction of their heat resistance by a short-term influence of hyperthermia (heating at the temperature of 42 °С during 1 minute have been investigated. The transitional increase of NO and H2O2 content, invoked by heating, was suppressed by the treatment of plantlets with the antagonists of calcium EGTA (chelator of exocellular calcium, lanthanum chloride (blocker of calcium channels of various types and neomycin (inhibitor of phosphatidylinositol-dependent phospholipase C. The rise of hydrogen peroxide content, caused by hardening, was partially suppressed by the action of inhibitors of nitrate reductase (sodium wolframate and NO-synthase (NG-nitro-L-arginine methyl ester – L-NAME, and the increasing of nitric oxide content was suppressed by the treatment of plants with the antioxidant ionol and with the scavenger of hydrogen peroxide (dimethylthiourea. These compounds and antagonists of calcium also partially removed the effect of the rise of plantlets’ heat resistance, invoked by hardening heating. The conclusion on calcium’s role in the activation of enzymatic systems, generating reactive oxygen species and nitric oxide, and on the functional interplay of these signal mediators at the induction of heat resistance of plantlets by hardening heating is made.

  4. Heat resistance of thermoduric enterococci isolated from milk.

    Science.gov (United States)

    McAuley, Catherine M; Gobius, Kari S; Britz, Margaret L; Craven, Heather M

    2012-03-15

    Enterococci are reported to survive pasteurisation but the extent of their survival is unclear. Sixty-one thermoduric enterococci isolates were selected from laboratory pasteurised milk obtained from silos in six dairy factories. The isolates were screened to determine log(10) reductions incurred after pasteurisation (63°C/30 min) and ranked from highest to lowest log(10) reduction. Two isolates each of Enterococcus faecalis, Enterococcus faecium, Enterococcus durans and Enterococcus hirae, exhibiting the median and the greatest heat resistance, as well as E. faecalis ATCC 19433, were selected for further heat resistance determinations using an immersed coil apparatus. D values were calculated from survival curves plotted from viable counts obtained after heating isolates in Brain Heart Infusion Broth at 63, 69, 72, 75 and 78°C followed by rapid cooling. At 72°C, the temperature employed for High Temperature Short Time (HTST) pasteurisation (72°C/15s), the D values extended from 0.3 min to 5.1 min, depending on the isolate and species. These data were used to calculate z values, which ranged from 5.0 to 9.8°C. The most heat sensitive isolates were E. faecalis (z values 5.0, 5.7 and 7.5°C), while the most heat resistant isolates were E. durans (z values 8.7 and 8.8°C), E. faecium (z value 9.0°C) and E. hirae (z values 8.5 and 9.8°C). The data show that heat resistance in enterococci is highly variable. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. 46 CFR 56.85-5 - Heating and cooling method.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Heating and cooling method. 56.85-5 Section 56.85-5... APPURTENANCES Heat Treatment of Welds § 56.85-5 Heating and cooling method. Heat treatment may be accomplished by a suitable heating method that will provide the desired heating and cooling rates, the required...

  6. Fault diagnosis methods for district heating substations

    Energy Technology Data Exchange (ETDEWEB)

    Pakanen, J.; Hyvaerinen, J.; Kuismin, J.; Ahonen, M. [VTT Building Technology, Espoo (Finland). Building Physics, Building Services and Fire Technology

    1996-12-31

    A district heating substation is a demanding process for fault diagnosis. The process is nonlinear, load conditions of the district heating network change unpredictably and standard instrumentation is designed only for control and local monitoring purposes, not for automated diagnosis. Extra instrumentation means additional cost, which is usually not acceptable to consumers. That is why all conventional methods are not applicable in this environment. The paper presents five different approaches to fault diagnosis. While developing the methods, various kinds of pragmatic aspects and robustness had to be considered in order to achieve practical solutions. The presented methods are: classification of faults using performance indexing, static and physical modelling of process equipment, energy balance of the process, interactive fault tree reasoning and statistical tests. The methods are applied to a control valve, a heat excharger, a mud separating device and the whole process. The developed methods are verified in practice using simulation, simulation or field tests. (orig.) (25 refs.)

  7. Heat-resistant materials 2. Conference proceedings of the 2. international conference on heat-resistant materials

    International Nuclear Information System (INIS)

    Natesan, K.; Ganesan, P.; Lai, G.Y.

    1995-01-01

    The Second International Conference on Heat-Resistant Materials was held in Gatlinburg, Tennessee, September 11--14, 1995 and focused on materials performance in cross-cutting technologies where heat resistant materials play a large and sometimes life-and performance-limiting roles in process schemes. The scope of materials for heat-resistant applications included structural iron- and nickel-base alloys, intermetallics, and ceramics. The conference focused on materials development, performance of materials in simulated laboratory and actual service environments on mechanical and structural integrity of components, and state-of-the-art techniques for processing and evaluating materials performance. The three keynote talks described the history of heat-resistant materials, relationship between microstructure and mechanical behavior, and applications of these materials in process schemes. The technical sessions included alloy metallurgy and properties, environmental effects and properties, deformation behavior and properties, relation between corrosion and mechanical properties, coatings, intermetallics, ceramics, and materials for waste incineration. Seventy one papers have been processed separately for inclusion on the data base

  8. KTA 625 alloy tube with excellent corrosion resistance and heat resistance

    International Nuclear Information System (INIS)

    Fujiwara, Kazuo; Kadonaga, Toshiki; Kikuma, Seiji.

    1982-01-01

    The problems when seamless tubes are produced by using nickel base 625 alloy (61Ni-22Cr-9Mo-Cb) which is known as a corrosion resistant and heat resistant alloyF were examined, and the confirmation experiment was carried out on its corrosion resistance and heat resistance. Various difficulties have been experienced in the tube making owing to the characteristics due to the chemical composition, but they were able to be solved by the repeated experiments. As for the characteristics of the product, the corrosion resistance was excellent particularly in the environment containing high temperature, high concentration chloride, and also the heat resistance was excellent in the wide temperature range from normal temperature to 1000 deg C. From these facts, the wide fields of application are expected for these alloy tubes, including the evaporation and concentration equipment for radioactive wastes in atomic energy field. Expecting the increase of demand hereafter, Kobe Steel Ltd. examined the problems when seamless tubes are produced from the 625 alloy by Ugine Sejournet process. The aptitude for tube production such as the chemical composition, production process and the product characteristics, the corrosion resistance against chloride, hydrogen sulfide, polythionic and other acids,F the high temperature strength and oxidation resistance are reported. (Kako, I.)

  9. SHORT COMMUNICATION EFFECT OF HEATING METHOD ON ...

    African Journals Online (AJOL)

    Preferred Customer

    employed or not: catalytic reduction and catalytic decomposition. The latter method has ... attention owing to their acidity, redox properties, and pseudo-liquid phase [6]. HPAs, in ... Reactor set-up and gas composition. .... min) was obtained, where it should be noted that by virtue of the design, this heating method will never ...

  10. Heat-resisting alloys for hard surfacing and sealing pad welding

    Directory of Open Access Journals (Sweden)

    R.O. Wielgosz

    2010-07-01

    Full Text Available The paper deals with heat-resisting alloys used to harden surfaces of elements operating in increased temperatures. It also deals with alloysused to seal cooperating surfaces of elements operating in the conditions of increased temperatures and aggressive utilities. Application methods and properties of thus obtained layers have been presented and adhesion of layers with matrix material has been assessed.

  11. Welding of heat-resistant 20% Cr-5% Al steels

    International Nuclear Information System (INIS)

    Tusek, J.; Arbi, D.; Kosmac, A.; Nartnik, U.

    2002-01-01

    The paper treats welding of heat-resistant ferritic stainless steels alloyed with approximately 20% Cr and 5% Al. The major part of the paper is dedicated to welding of 20% Cr-5% Al steel with 3 mm in thickness. Welding was carried out with five different welding processes, i. e., manual metal-arc, MIG, TIG, plasma arc, and laser beam welding processes, using a filler material and using no filler material, respectively. The welded joints obtained were subjected to mechanical tests and the analysis of microstructure in the weld metal and the transition zone. The investigations conducted showed that heat-resistant ferritic stainless 20% Cr-5% Al steel can be welded with fusion welding processes using a Ni-based filler material. (orig.)

  12. Monitoring of high temperature area by resistivity tomography during in-situ heating test in sedimentary soft rocks

    International Nuclear Information System (INIS)

    Kubota, Kenji; Suzuki, Koichi; Ikenoya, Takafumi; Takakura, Nozomu; Tani, Kazuo

    2009-01-01

    One of the major issues in disposal of nuclear waste is that the long term behaviors of sedimentary soft rocks can be affected by various environmental factors such as temperature, mechanical conditions or hydraulic conditions. Therefore, it is necessary to develop a method for evaluating the long term stability of caverns in sedimentary soft rocks as subjected to changes of environment. We have conducted in-situ heating test to evaluate the influence of high temperature to the surrounding rock mass at a depth of 50 m. The well with a diameter of 30 cm and 60 cm of height, was drilled and filled with groundwater. The heater was installed in the well for heating the surrounding rock mass. During the heating, temperature and deformation around the well were measured. To evaluate the influence of heating on sedimentary soft rocks, it is important to monitor the extent of heated area. Resistivity monitoring is thought to be effective to map the extent of the high temperature area. So we have conducted resistivity tomography during the heating test. The results demonstrated that the resistivity of the rock mass around the heating well decreased and this area was gradually expanded from the heated area during the heating. The decreasing rate of resistivity on temperature is correlated to that of laboratory experimental result and existing empirical formula between aqueous solution resistivity and temperature. Resistivity is changed by many other factors, but it is expected that resistivity change by other factors is very few in this test. This suggests that high temperature area is detected and spatial distribution of temperature can be mapped by resistivity tomography. So resistivity tomography is expected to be one of the promising methods to monitor the area heated by nuclear waste. (author)

  13. Alloying principles for magnesium base heat resisting alloys

    International Nuclear Information System (INIS)

    Drits, M.E.; Rokhlin, L.L.; Oreshkina, A.A.; Nikitina, N.I.

    1982-01-01

    Some binary systems of magnesium-base alloys in which solid solutions are formed, are considered for prospecting heat resistant alloys. It is shown that elements having essential solubility in solid magnesium strongly decreasing with temperature should be used for alloying maqnesium base alloys with high strength properties at increased temperatures. The strengthening phases in these alloys should comprise essential quantity of magnesium and be rather refractory

  14. Design of a pressurized water loop heated by electric resistances

    International Nuclear Information System (INIS)

    Ribeiro, S.V.G.

    1981-01-01

    A pressurized water loop design is presented. Its operating pressure is 420 psi and we seek to simulate qualitatively some thermo-hydraulic phenomena of PWR reactors. The primary circuit simulator consists basically of two elements: 1)the test section housing 16 electric resistences dissipating a total power of 100 Kw; 2)the loop built of SCH40S 304L steel piping, consisting of the pump, a heat exchanger and the pressurizer. (Author) [pt

  15. Surface Resistance Measurements and Estimate of the Beam-Induced Resistive Wall Heating of the LHC Dipole Beam Screen

    CERN Document Server

    Caspers, Friedhelm; Ruggiero, F; Tan, J

    1999-01-01

    An estimate of the resistive losses in the LHC beam screen is given from cold surface resistance measurements using the shielded pair technique, with particular emphasis on the effect of a high magnetic field. Two different copper coating methods, namely electro-deposition and co-lamination, have been evaluated. Experimental data are compared with theories including the anomalous skin effect and the magneto-resistance effect. It is shown whether the theory underestimates or not the losses depends strongly on the RRR value, on the magnetic field and on the surface characteristics. In the pessimistic case and for nominal machine parameters, the estimated beam-induced resistive wall heating can be as large as 260 mW/m for two circulating beams.

  16. Corrosion resistance of heat exchange equipment in hydrotreating Orenburg Condensate

    International Nuclear Information System (INIS)

    Teslya, B.M.; Burlov, V.V.; Parputs, I.V.; Parputs, T.P.

    1986-01-01

    The authors study the corrosion resistance of materials of construction and select appropriate materials for the fabrication of heat exchange equipment that will be serviceable under hydrotreating conditions. This paper discusses the Orenburg condensate hydrotreating unit which has been shut down repeatedly for repair because of corrosion damage to components of heat exchangers in the reactor section: tube bundles (08Kh18N10T steel), corrugated compensators (12Kh18N10T steel), and pins of the floating heads (37Kh13N8G8MFB steel). The authors recommend that the tube bundles and the compensators in heat exchangers in the reaction section should be fabricated of 08Kh21N6M2T or 10Kh17N13M2T steel. The pins have been replaced by new pins made of 10Kh17N13 X M2T steel, increasing the service life from 6-12 months to 2 years

  17. Axial flow heat exchanger devices and methods for heat transfer using axial flow devices

    Science.gov (United States)

    Koplow, Jeffrey P.

    2016-02-16

    Systems and methods described herein are directed to rotary heat exchangers configured to transfer heat to a heat transfer medium flowing in substantially axial direction within the heat exchangers. Exemplary heat exchangers include a heat conducting structure which is configured to be in thermal contact with a thermal load or a thermal sink, and a heat transfer structure rotatably coupled to the heat conducting structure to form a gap region between the heat conducting structure and the heat transfer structure, the heat transfer structure being configured to rotate during operation of the device. In example devices heat may be transferred across the gap region from a heated axial flow of the heat transfer medium to a cool stationary heat conducting structure, or from a heated stationary conducting structure to a cool axial flow of the heat transfer medium.

  18. Analytical method for establishing indentation rolling resistance

    Directory of Open Access Journals (Sweden)

    Gładysiewicz Lech

    2018-01-01

    Full Text Available Belt conveyors are highly reliable machines able to work in special operating conditions. Harsh environment, long distance of transporting and great mass of transported martials are cause of high energy usage. That is why research in the field of belt conveyor transportation nowadays focuses on reducing the power consumption without lowering their efficiency. In this paper, previous methods for testing rolling resistance are described, and new method designed by authors was presented. New method of testing rolling resistance is quite simple and inexpensive. Moreover it allows to conduct the experimental tests of the impact of different parameters on the value of indentation rolling resistance such as core design, cover thickness, ambient temperature, idler travel frequency, or load value as well. Finally results of tests of relationship between rolling resistance and idler travel frequency and between rolling resistance and idler travel speed was presented.

  19. Analytical method for establishing indentation rolling resistance

    Science.gov (United States)

    Gładysiewicz, Lech; Konieczna, Martyna

    2018-01-01

    Belt conveyors are highly reliable machines able to work in special operating conditions. Harsh environment, long distance of transporting and great mass of transported martials are cause of high energy usage. That is why research in the field of belt conveyor transportation nowadays focuses on reducing the power consumption without lowering their efficiency. In this paper, previous methods for testing rolling resistance are described, and new method designed by authors was presented. New method of testing rolling resistance is quite simple and inexpensive. Moreover it allows to conduct the experimental tests of the impact of different parameters on the value of indentation rolling resistance such as core design, cover thickness, ambient temperature, idler travel frequency, or load value as well. Finally results of tests of relationship between rolling resistance and idler travel frequency and between rolling resistance and idler travel speed was presented.

  20. Study on the Thermal Resistance of Multi-chip Module High Power LED Packaging Heat Dissipation System

    Directory of Open Access Journals (Sweden)

    Kailin Pan

    2014-10-01

    Full Text Available Thermal resistance is a key technical index which indicates the thermal management of multi-chip module high power LED (MCM-LED packaging heat dissipation system. In this paper, the prototype structure of MCM-LED packaging heat dissipation system is proposed to study the reliable thermal resistance calculation method. In order to analyze the total thermal resistance of the MCM-LED packaging heat dissipation system, three kinds of thermal resistance calculation method including theoretical calculation, experimental testing and finite element simulation are developed respectively. Firstly, based on the thermal resistance network model and the principle of steady state heat transfer, the theoretical value of total thermal resistance is 6.111 K/W through sum of the thermal resistance of every material layer in the major direction of heat flow. Secondly, the thermal resistance experiment is carried out by T3Ster to obtain the experimental result of total thermal resistance, and the value is 6.729 K/W. Thirdly, a three-dimensional finite element model of MCM-LED packaging heat dissipation system is established, and the junction temperature experiment is also performed to calculated the finite element simulated result of total thermal resistance, the value is 6.99 K/W. Finally, by comparing the error of all the three kinds of result, the error of total thermal resistance between the theoretical value and experimental result is 9.2 %, and the error of total thermal resistance between the experimental result and finite element simulation is only about -3.9 %, meanwhile, the main reason of each error is discussed respectively.

  1. Larson-Miller Constant of Heat-Resistant Steel

    Science.gov (United States)

    Tamura, Manabu; Abe, Fujio; Shiba, Kiyoyuki; Sakasegawa, Hideo; Tanigawa, Hiroyasu

    2013-06-01

    Long-term rupture data for 79 types of heat-resistant steels including carbon steel, low-alloy steel, high-alloy steel, austenitic stainless steel, and superalloy were analyzed, and a constant for the Larson-Miller (LM) parameter was obtained in the current study for each material. The calculated LM constant, C, is approximately 20 for heat-resistant steels and alloys except for high-alloy martensitic steels with high creep resistance, for which C ≈ 30 . The apparent activation energy was also calculated, and the LM constant was found to be proportional to the apparent activation energy with a high correlation coefficient, which suggests that the LM constant is a material constant possessing intrinsic physical meaning. The contribution of the entropy change to the LM constant is not small, especially for several martensitic steels with large values of C. Deformation of such martensitic steels should accompany a large entropy change of 10 times the gas constant at least, besides the entropy change due to self-diffusion.

  2. Development of late blight resistance and heat tolerance through gamma irradiation of shoot cultures in potato

    International Nuclear Information System (INIS)

    Gosal, S.S.; Jitender Kaur, Adas; Minocha, J.L.

    2001-01-01

    In vitro shoot cultures of two potato varieties viz., Kufri jyoti and Kufri Chandramukhi were gamma irradiated at 20 Gy and 40 Gy. Micro tubers were induced in micro propagated M1V3 generation. For heat tolerance micro tubers were induced at elevated (28 C ) incubation temperature (optimum being 20 1C ) and were characterized by early sowing, chlorophyll persistence and harvest index. The number of micro tubers/plant was highly reduced at elevated temperature and the resulting tubers exhibited distorted shapes and growth of apical buds. Thus obtained micro tubers exhibited better germination (62.3%) even in early sowing at relatively higher temperature. The progenies from putative heat tolerant plants were grown in the field by sowing at higher temperature for four subsequent generations. Heat tolerant plants segregated in each generation but the frequency of heat tolerant plants increased in the advanced generation. For developing late blight resistance micro tubers produced from irradiated shoot cultures were sown in pots and resulting plants were screened using detached leaf method. The progenies of putative resistant plants grown in the field were artificially inoculated with sporangial inoculum of Phytophthora infection's. Field grown plants exhibited segregation with respect to disease reaction and about 56 per cent plants showed resistance. Segregation was reduced during following generation and the frequency of resistant plants was increased up to 72.3 per cent. Thus, repeated selections has helped in developing stable mutants in both the varieties

  3. Strength of heat-resistant materials. Vynoslivost' zharoprochnykh materialov

    Energy Technology Data Exchange (ETDEWEB)

    Akimov, L M

    1977-01-01

    A presentation is made of the research results of the effect that metallurgical, technological, construction, and exploitation factors have on the durability of heat-resistant alloys, tested for mechanical, heat, and corrosion effects on metal in standard cylindrical and specially contoured samples under conventional conditions and conditional approaching operational ones. The causes of changes in fatigue strength of alloys are explained by the use of fractographic and metallographic analyses of fractures and structure. The book is intended for engineering--technical personnel at research institutes, and plant mechanical and metal studies laboratories in machine-building factories. The book may also be used by undergraduate and graduate students at institutions of higher learning specializing in the field of material studies and mechanical testing of steels and alloys. 176 references, 79 figures, 12 tables.

  4. Heat Resistance of Glued Finger Joints in Spruce Wood Constructions

    Directory of Open Access Journals (Sweden)

    Martin Sviták

    2014-10-01

    Full Text Available The heat resistance of glued spruce wood was evaluated for different joint types and adhesives. Bending strength, modulus of elasticity, and also fracture evaluation were investigated on glued spruce samples made by the finger-jointed principle. Finger-jointed samples were glued with polyurethane (PUR and melamine-urea-formaldehyde (MUF adhesives. Heat loading was realized at temperatures 60, 80, and 110 °C and compared with wood with 20 °C. A static bending test with four-point flexural test was used. Elevated temperature and adhesive type had an important influence on the bending strength. On the other hand, adhesive type had a significant influence on the modulus of elasticity, but elevated temperature had no substantial influence.

  5. Viability and heat resistance of murine norovirus on bread.

    Science.gov (United States)

    Takahashi, Michiko; Takahashi, Hajime; Kuda, Takashi; Kimura, Bon

    2016-01-04

    Contaminated bread was the cause of a large-scale outbreak of norovirus disease in Japan in 2014. Contamination of seafood and uncooked food products by norovirus has been reported several times in the past; however the outbreak resulting from the contamination of bread products was unusual. A few reports on the presence of norovirus on bread products are available; however there have been no studies on the viability and heat resistance of norovirus on breads, which were investigated in this study. ce:italic>/ce:italic> strain 1 (MNV-1), a surrogate for human norovirus, was inoculated directly on 3 types of bread, but the infectivity of MNV-1 on bread samples was almost unchanged after 5days at 20°C. MNV-1 was inoculated on white bread that was subsequently heated in a toaster for a maximum of 2min. The results showed that MNV-1 remained viable if the heating period was insufficient to inactivate. In addition, bread dough contaminated with MNV-1 was baked in the oven. Our results indicated that MNV-1 may remain viable on breads if the heating duration or temperature is insufficient. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Influence of heat treatment on corrosive resistance of concrete steels

    International Nuclear Information System (INIS)

    Woldan, A.; Suliga, I.; Kusinski, J.; Jazowy, R.

    1998-01-01

    The reinforcing bars are essential elements of ferro-concrete structures. During the building structure service the reinforcing bars should co-operate with surrounding concrete. Any bonding defects as well as corrosion induced strength reduction may result in construction failure. The reinforcing steel working environment is determined by concrete chemical and phase composition and surrounding environmental properties. The aggressive corrosive activity of the letter implies necessity of effective ways development to protect elements against corrosion. The effect of heat treatment, increased Si content in steel on corrosion resistance of reinforcing steel in concrete was studied in the current work. Corrosion tests and metallographic examinations proved a positive influence of hardening and Si enrichment on corrosion resistance of reinforcing bars in ferro-concrete structures. (author)

  7. Maleimido substituted cyclotriphosphazene resins for fire and heat resistant composites

    Science.gov (United States)

    Kumar, D.; Fohlen, G. M.; Parker, J. A.

    1983-01-01

    A new class of fire- and heat-resistant matrix resins have been synthesized by the thermal polymerization of maleimido substituted phenoxycyclotriphosphazenes. The resins have exhibited a char yield of 82 percent at 800 C in nitrogen and 81 percent at 700 C in air. Graphite-fabric laminates based on a resin of this class have shown a limiting oxygen index of 100 percent even at 300 C. Details of the fabrication of the resins and the composites and testing procedures are discussed.

  8. Heat-resistant mechanism of transgenic rape by 45Ca isotope tracer

    International Nuclear Information System (INIS)

    Xu Falun; Yang Yuanyou; Liu Ning; Liao Jiali; Yang Jijun; Tang Jun; Liu Zhibin; Yang Yi

    2012-01-01

    The Ca 2+ uptake differences of the rape with heat-resistant gene and the general rape were investigated by 45 Ca isotope tracer. The results showed that the rape with heat-resistant gene can strengthen the regulation of calcium absorption. The calcium regulation ability of the heat-resistant genes may be able to play in the rape aspect of the mechanism of resistance. (authors)

  9. Biofilm Formation Potential of Heat-Resistant Escherichia coli Dairy Isolates and the Complete Genome of Multidrug-Resistant, Heat-Resistant Strain FAM21845.

    Science.gov (United States)

    Marti, Roger; Schmid, Michael; Kulli, Sandra; Schneeberger, Kerstin; Naskova, Javorka; Knøchel, Susanne; Ahrens, Christian H; Hummerjohann, Jörg

    2017-08-01

    We tested the biofilm formation potential of 30 heat-resistant and 6 heat-sensitive Escherichia coli dairy isolates. Production of curli and cellulose, static biofilm formation on polystyrene (PS) and stainless steel surfaces, biofilm formation under dynamic conditions (Bioflux), and initial adhesion rates (IAR) were evaluated. Biofilm formation varied greatly between strains, media, and assays. Our results highlight the importance of the experimental setup in determining biofilm formation under conditions of interest, as correlation between different assays was often not a given. The heat-resistant, multidrug-resistant (MDR) strain FAM21845 showed the strongest biofilm formation on PS and the highest IAR and was the only strain that formed significant biofilms on stainless steel under conditions relevant to the dairy industry, and it was therefore fully sequenced. Its chromosome is 4.9 Mb long, and it harbors a total of five plasmids (147.2, 54.2, 5.8, 2.5, and 1.9 kb). The strain carries a broad range of genes relevant to antimicrobial resistance and biofilm formation, including some on its two large conjugative plasmids, as demonstrated in plate mating assays. IMPORTANCE In biofilms, cells are embedded in an extracellular matrix that protects them from stresses, such as UV radiation, osmotic shock, desiccation, antibiotics, and predation. Biofilm formation is a major bacterial persistence factor of great concern in the clinic and the food industry. Many tested strains formed strong biofilms, and especially strains such as the heat-resistant, MDR strain FAM21845 may pose a serious issue for food production. Strong biofilm formation combined with diverse resistances (some encoded on conjugative plasmids) may allow for increased persistence, coselection, and possible transfer of these resistance factors. Horizontal gene transfer may conceivably occur in the food production setting or the gastrointestinal tract after consumption. Copyright © 2017 Marti et al.

  10. Heat-resistant, extended-spectrum β-lactamase-producing Klebsiella pneumoniae in endoscope-mediated outbreak

    DEFF Research Database (Denmark)

    Jørgensen, S.B.; Bojer, Martin Saxtorph; Boll, E.J.

    2016-01-01

    disinfection in a decontaminator designated for such use. The genetic marker clpK, which increases microbial heat resistance, has previously been described in K. pneumoniae outbreak strains. Aim To investigate the role of clpK in biofilm formation and heat-shock stability in the outbreak strain. Methods...... construction and heat-shock assays. Findings Five patients and one intubation endoscope contained K. pneumoniae with the same amplified fragment length polymorphism pattern. The outbreak strain contained the clpK genetic marker, which rendered the strain its increased heat resistance. The survival rate....... Heat resistance of certain K. pneumoniae strains may facilitate survival in biofilms on medical equipment and hence increase the potential of those strains to persist and disperse in the hospital environment....

  11. Resistance to corrosion fatigue fracture in heat resistant steels and their welded joints

    International Nuclear Information System (INIS)

    Timofeev, B.T.; Fedorova, V.A.; Zvezdin, Yu.I.; Vajner, L.A.; Filatov, V.M.

    1987-01-01

    Experimental data on cyclic crack resistance of heat-resistant steels and their welded joints employed for production of the reactor bodies are for the first time generalized and systematized. The formula is suggested accounting for surface and inner defects to calculate the fatigue crack growth in the process of operation. This formula for surface defects regards also the effect of the corrosion factor. Mechanisms of the reactor water effect on the fatigue crack growth rate are considered as well as a combined effect of radiation and corrosive medium on this characteristic

  12. Analysis of creep effective stress in austenitic heat resistant steel

    International Nuclear Information System (INIS)

    Park, In Duck; Nam, Ki Woo

    2002-01-01

    This paper describes the comparison of calculated effective stress with experimental one in austenitic heat resistant steels, STS310J1TB and STS310S with and without a small amount of Nb and N. Based on a solute atoms diffusion model, contribution from soluble nitrogen to the high-temperature strength was numerically examined for austenitic heat-resisting Fe-Cr-Ni-N(STS310J1TB) and Fe-Cr-Ni(STS310S) alloys. The solute atmosphere dragging stress of dislocation was calculated in optional dislocation velocity of STS310J1TB and STS310S at 650 degree C, 675 degree C and 700 degree C. As a result of the numerical calculation, the solute atmosphere dragging stress of STS310J1TB was about 50 times larger than that of STS310S. When the temperature became high, the maximum value of solute atmosphere dragging stress was small and the velocity of moving dislocation was fast. From the relationship between the dislocation rate and the solute atmosphere dragging stress, the relation of both was proportional and the inclination is about 1 in the level with low velocity of moving dislocation. From above results, the mechanism of dislocation movement in STS310J1TB was the solute atmosphere dragging stress. The solute atmosphere dragging stress, which was calculated from the numerical calculation was close to the effect stress in stress relaxation tests

  13. Baking of carbon anodes for the electrolysis of aluminium by electric resistance heating

    Energy Technology Data Exchange (ETDEWEB)

    Schultze-Rhonhof, E.

    1981-09-01

    The aim of the project was the development of a method of baking carbon anodes for the aluminium industry by direct electric resistance heating. A distinct reduction of the energy input compared with the usual methods is possible. At the same time fossil energy (oil, gas) will be substituted by electric energy. An experimental arrangement for baking carbon anodes built during the project baking experiments, in 1:1 scale was realized. The quality of the baked anodes has been investigated. Carbon anodes in a 1:1 scale can be baked uniformly by direct electric resistance heating. The characteristic chemical and physical data meets all requirements of the aluminium industry. The energy input has not yet come up to expectations.

  14. Mixture for producing fracture-resistant, fiber-reinforced ceramic material by microwave heating

    Science.gov (United States)

    Meek, T.T.; Blake, R.D.

    1985-04-03

    A fracture-resistant, fiber-reinforced ceramic substrate is produced by a method which involves preparing a ceramic precursor mixture comprising glass material, a coupling agent, and resilient fibers, and then exposing the mixture to microwave energy. The microwave field orients the fibers in the resulting ceramic material in a desired pattern wherein heat later generated in or on the substrate can be dissipated in a desired geometric pattern parallel to the fiber pattern. Additionally, the shunt capacitance of the fracture-resistant, fiber-reinforced ceramic substrate is lower which provides for a quicker transit time for electronic pulses in any conducting pathway etched into the ceramic substrate.

  15. Thermopower measurement under high pressure using 'seesaw heating method'

    International Nuclear Information System (INIS)

    Hedo, M; Nakamura, D; Takaesu, Y; Yagasaki, K; Nakama, T; Fujiwara, T; Uchima, K

    2010-01-01

    We have developed a set-up with modified 'seesaw heating method' for the thermopower measurement under pressures P up to 3 GPa at the temperature range between 2 K and 300 K. By using this set-up, the thermopower and electrical resistivity of the single crystalline YbMn 2 Ge 2 under high pressure were measured with enough accuracy. S(T) curve shows the characteristic feature at the magnetic transition in all pressure range, while no evidence of the magnetic phase transition is observed in ρ(T) at P > 1.25 GPa. The measurement results indicate that the simultaneous measurement of the thermopower and electrical resistivity is a useful tool to study the pressure-induced phase transitions.

  16. Genome-wide deficiency screen for the genomic regions responsible for heat resistance in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Teramura Kouhei

    2011-06-01

    Full Text Available Abstract Background Temperature adaptation is one of the most important determinants of distribution and population size of organisms in nature. Recently, quantitative trait loci (QTL mapping and gene expression profiling approaches have been used for detecting candidate genes for heat resistance. However, the resolution of QTL mapping is not high enough to examine the individual effects of various genes in each QTL. Heat stress-responsive genes, characterized by gene expression profiling studies, are not necessarily responsible for heat resistance. Some of these genes may be regulated in association with the heat stress response of other genes. Results To evaluate which heat-responsive genes are potential candidates for heat resistance with higher resolution than previous QTL mapping studies, we performed genome-wide deficiency screen for QTL for heat resistance. We screened 439 isogenic deficiency strains from the DrosDel project, covering 65.6% of the Drosophila melanogaster genome in order to map QTL for thermal resistance. As a result, we found 19 QTL for heat resistance, including 3 novel QTL outside the QTL found in previous studies. Conclusion The QTL found in this study encompassed 19 heat-responsive genes found in the previous gene expression profiling studies, suggesting that they were strong candidates for heat resistance. This result provides new insights into the genetic architecture of heat resistance. It also emphasizes the advantages of genome-wide deficiency screen using isogenic deficiency libraries.

  17. Methodology of heat transfer and flow resistance measurement for matrices of rotating regenerative heat exchangers

    Directory of Open Access Journals (Sweden)

    Butrymowicz Dariusz

    2016-09-01

    Full Text Available The theoretical basis for the indirect measurement approach of mean heat transfer coefficient for the packed bed based on the modified single blow technique was presented and discussed in the paper. The methodology of this measurement approach dedicated to the matrix of the rotating regenerative gas heater was discussed in detail. The testing stand consisted of a dedicated experimental tunnel with auxiliary equipment and a measurement system are presented. Selected experimental results are presented and discussed for selected types of matrices of regenerative air preheaters for the wide range of Reynolds number of gas. The agreement between the theoretically predicted and measured temperature profiles was demonstrated. The exemplary dimensionless relationships between Colburn heat transfer factor, Darcy flow resistance factor and Reynolds number were presented for the investigated matrices of the regenerative gas heater.

  18. The Heat Resistance of Microbial Cells Represented by D Values Can be Estimated by the Transition Temperature and the Coefficient of Linear Expansion.

    Science.gov (United States)

    Nakanishi, Koichi; Kogure, Akinori; Deuchi, Keiji; Kuwana, Ritsuko; Takamatsu, Hiromu; Ito, Kiyoshi

    2015-01-01

    We previously developed a method for evaluating the heat resistance of microorganisms by measuring the transition temperature at which the coefficient of linear expansion of a cell changes. Here, we performed heat resistance measurements using a scanning probe microscope with a nano thermal analysis system. The microorganisms studied included six strains of the genus Bacillus or related genera, one strain each of the thermophilic obligate anaerobic bacterial genera Thermoanaerobacter and Moorella, two strains of heat-resistant mold, two strains of non-sporulating bacteria, and one strain of yeast. Both vegetative cells and spores were evaluated. The transition temperature at which the coefficient of linear expansion due to heating changed from a positive value to a negative value correlated strongly with the heat resistance of the microorganism as estimated from the D value. The microorganisms with greater heat resistance exhibited higher transition temperatures. There was also a strong negative correlation between the coefficient of linear expansion and heat resistance in bacteria and yeast, such that microorganisms with greater heat resistance showed lower coefficients of linear expansion. These findings suggest that our method could be useful for evaluating the heat resistance of microorganisms.

  19. Effect of technological procedures on the crack resistance of nickel alloy welded joints under heat treatment

    International Nuclear Information System (INIS)

    Bagdasarov, Yu.S.; Sorokin, L.I.; Yakushin, B.F.; Moryashchev, S.F.

    1983-01-01

    Comparison of the efficiency of some technological procedures directed to the increase of crack resistance of KhN50MBKTYUR (EhP99) alloy welded joints under heat treatment was conducted. Welded joints were manufactured by the methods of electron beam welding, laser welding, automatic argon-arc welding. The latter was conducted by conventional technology as well as with electromagnetic mixing of liquid metal of welding bath, with compulsory cooling of weld matal, with pulse arc. It is shown that the high fracture resistance of welded joints, manufactured by electron beam and laser welding is achieved by combination of high mechanical properties of heat affected zone metal and reduced elastic potential energy margin of residual welding stresses (as compared to argon-arc welding)

  20. Application of newly developed heat resistant materials for USC boilers

    International Nuclear Information System (INIS)

    Sato, T.; Tamura, K.; Fukuda, Y.; Matsuda, J.

    2004-01-01

    This paper describes the research on the development and improvement of new high strength heat resistant steels such as SUPER304H (18Cr-9Ni-3Cu-Nb-N), NF709 (20Cr-25Ni-1.5Mo-Nb-Ti-N) and HR3C (25Cr-20Ni-Nb-N) as boiler tube, and NF616 (9Cr-0.5Mo-1.8W-Nb-V) and HCM12A (11Cr-0.4Mo-2W-Nb-V-Cu) as thick section pipe. The latest manufacturing techniques applied for these steels are introduced. In addition the high temperature strength of Alloy617 (52Ni-22Cr-13Co-9Mo-Ti-Al) that is one of the candidate materials for the next generation 700 □ USC boilers is described. (orig.)

  1. Integrated Thermal Protection Systems and Heat Resistant Structures

    Science.gov (United States)

    Pichon, Thierry; Lacoste, Marc; Glass, David E.

    2006-01-01

    In the early stages of NASA's Exploration Initiative, Snecma Propulsion Solide was funded under the Exploration Systems Research & Technology program to develop integrated thermal protection systems and heat resistant structures for reentry vehicles. Due to changes within NASA's Exploration Initiative, this task was cancelled early. This presentation provides an overview of the work that was accomplished prior to cancellation. The Snecma team chose an Apollo-type capsule as the reference vehicle for the work. They began with the design of a ceramic aft heatshield (CAS) utilizing C/SiC panels as the capsule heatshield, a C/SiC deployable decelerator and several ablators. They additionally developed a health monitoring system, high temperature structures testing, and the insulation characterization. Though the task was pre-maturely cancelled, a significant quantity of work was accomplished.

  2. Pengaruh Pretreatment Secara Alkalisasi-Resistive Heating terhadap Kandungan Lignoselulosa Jerami Padi

    Directory of Open Access Journals (Sweden)

    Dewi Maya Maharani

    2017-09-01

    Full Text Available Cellulose is a potential biomass that is used for bioethanol production and commonly present in agricultural residues like rice straw. Cellulose is an important material to produce glucose and bioethanol, but it is covered by lignin and hemicellulose bonds to form a lignocellulose.  Bioethanol production using basic material containing cellulose requires special attention in the process of pretreatment for lignin degradation process and increase the accessible surface and decrystallize cellulose. The aim of this research was to apply alkalization and resistive heating combine method for rice straw pretreatment process before further being converted into bioethanol and to determine the effects of heating temperature and NaOH concentration on the content of  lignin, cellulose, and hemicellulose. The reactor had been designed for resistive heating process. Rice straw that was resized into 100 mesh has dissolved with 0.03 M, 0.05 M, and 0.07 M NaOH and heated with resistive heating temperature of 75 oC, 85 oC, and 99 oC. Cellulose is a raw material that will be further converted into glucose. So that, the selected optimum conditions of this study were  pretreatment with the highest increase of cellulose content level until 8.88% and resulted decreasing levels of lignin (1.39% and hemicellulose (4.33% by temperature  75 oC and 0.07 M NaOH concentration. Resistive heating that combine with alkalization can be used for rice straw pretreatment process that reduce lignin and hemicellulose content as well as increasing cellulose content.   ABSTRAK Selulosa merupakan biomassa yang potensial digunakan untuk produksi bioetanol dan banyak ditemukan di residu pertanian seperti jerami padi. Selulosa merupakan material penting yang dapat dikonversi menjadi glukosa kemudian dikonversi menjadi bioetanol, namun selulosa pada alam dilapisi oleh ikatan lignin dan hemiselulosa menjadi lignoselulosa. Pembuatan bioetanol berbasis selulosa membutuhkan proses

  3. Heat pipe and method of production of a heat pipe

    International Nuclear Information System (INIS)

    Kemp, R.S.

    1975-01-01

    The heat pipe consists of a copper pipe in which a capillary network or wick of heat-conducting material is arranged in direct contact with the pipe along its whole length. Furthermore, the interior space of the tube contains an evaporable liquid for pipe transfer. If water is used, the capillary network consists of, e.g., a phosphorus band network. To avoid contamination of the interior of the heat pipe during sealing, its ends are closed by mechanical deformation so that an arched or plane surface is obtained which is in direct contact with the network. After evacuation of the interior space, the remaining opening is closed with a tapered pin. The ratio wall thickness/tube diameter is between 0.01 and 0.6. (TK/AK) [de

  4. Heat resistance of Salmonella in various egg products.

    Science.gov (United States)

    Garibaldi, J A; Straka, R P; Ijichi, K

    1969-04-01

    The heat-resistance characteristics of Salmonella typhimurium Tm-1, a reference strain in the stationary phase of growth, were determined at several temperatures in the major types of products produced by the egg industry. The time required to kill 90% of the population (D value) at a given temperature in specific egg products was as follows: at 60 C (140 F), D = 0.27 min for whole egg; D = 0.60 min for whole egg plus 10% sucrose; D = 1.0 min for fortified whole egg; D = 0.20 min for egg white (pH 7.3), stabilized with aluminum; D = 0.40 min for egg yolk; D = 4.0 min for egg yolk plus 10% sucrose; D = 5.1 min for egg yolk plus 10% NaCl; D = 1.0 min for scrambled egg mix; at 55 C (131 F), D = 0.55 min for egg white (pH 9.2); D = 1.2 min for egg white (pH 9.2) plus 10% sucrose. The average Z value (number of degrees, either centigrade or fahrenheit, for a thermal destruction time curve to traverse one logarithmic cycle) was 4.6 C (8.3 F) with a range from 4.2 to 5.3 C. Supplementation with 10% sucrose appeared to have a severalfold greater effect on the heat stabilization of egg white proteins than on S. typhimurium Tm-1. This information should be of value in the formulation of heat treatments to insure that all egg products be free of viable salmonellae.

  5. Inverse Problem and Variation Method to Optimize Cascade Heat Exchange Network in Central Heating System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yin; WEI Zhiyuan; ZHANG Yinping; WANG Xin

    2017-01-01

    Urban heating in northern China accounts for 40% of total building energy usage.In central heating systems,heat is often transfened from heat source to users by the heat network where several heat exchangers arc installed at heat source,substations and terminals respectively.For given overall heating capacity and heat source temperarure,increasing the terminal fluid temperature is an effective way to improve the thermal performance of such cascade heat exchange network for energy saving.In this paper,the mathematical optimization model of the cascade heat exchange network with three-stage heat exchangers in series is established.Aim at maximizing the cold fluid temperature for given hot fluid temperature and overall heating capacity,the optimal heat exchange area distribution and the medium fluids' flow rates are determined through inverse problem and variation method.The preliminary results show that the heat exchange areas should be distributed equally for each heat exchanger.It also indicates that in order to improve the thernmal performance of the whole system,more heat exchange areas should be allocated to the heat exchanger where flow rate difference between two fluids is relatively small.This work is important for guiding the optimization design of practical cascade heating systems.

  6. The influence of sodium chlorides fog on corrosion resistance of heat exchangers used in automotive

    Directory of Open Access Journals (Sweden)

    Peta Katarzyna

    2017-01-01

    Full Text Available In the work, the most important factors which influence on the exploitative durability of heat exchangers are classified. Particular attention was paid to the compounds of sodium chloride used in the winter season for road maintenance. In order to determine their impact on automotive heat exchanger corrosion resistance, a test of heaters in a salt chamber which imitates the conditions of their work was realized. It also allows to verify the durability of these products. To evaluate the corrosion changes, observation with the use of light microscopy and scanning microscopy SEM were made supplemented with microanalysis of chemical composition by EDS spectroscopy method. Critical areas in the heat exchangers which are mostly exposed to damage including the formation of local corrosion pits were located and analyzed.

  7. 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)

  8. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    Science.gov (United States)

    Phillips, B.A.; Zawacki, T.S.

    1998-07-21

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration. 5 figs.

  9. Derivation of effectiveness-NTU method for heat exchangers with heat leak; TOPICAL

    International Nuclear Information System (INIS)

    William M. Soyars

    2001-01-01

    A powerful and useful method for heat exchanger analysis is the effectiveness-NTU method. The equations for this technique presented in textbooks, however, are limited to the case where all of the heat transfer occurs between the two fluid streams. In an application of interest to us, cryogenic heat exchangers, we wish to consider a heat leak term. Thus, we have derived equations for the(var e psilon)-NTU method with heat leak involved. The cases to be studied include evaporators, condensers, and counter-flow, with heat leak both in and out

  10. Dynamic thermal characteristics of heat pipe via segmented thermal resistance model for electric vehicle battery cooling

    Science.gov (United States)

    Liu, Feifei; Lan, Fengchong; Chen, Jiqing

    2016-07-01

    Heat pipe cooling for battery thermal management systems (BTMSs) in electric vehicles (EVs) is growing due to its advantages of high cooling efficiency, compact structure and flexible geometry. Considering the transient conduction, phase change and uncertain thermal conditions in a heat pipe, it is challenging to obtain the dynamic thermal characteristics accurately in such complex heat and mass transfer process. In this paper, a ;segmented; thermal resistance model of a heat pipe is proposed based on thermal circuit method. The equivalent conductivities of different segments, viz. the evaporator and condenser of pipe, are used to determine their own thermal parameters and conditions integrated into the thermal model of battery for a complete three-dimensional (3D) computational fluid dynamics (CFD) simulation. The proposed ;segmented; model shows more precise than the ;non-segmented; model by the comparison of simulated and experimental temperature distribution and variation of an ultra-thin micro heat pipe (UMHP) battery pack, and has less calculation error to obtain dynamic thermal behavior for exact thermal design, management and control of heat pipe BTMSs. Using the ;segmented; model, the cooling effect of the UMHP pack with different natural/forced convection and arrangements is predicted, and the results correspond well to the tests.

  11. Effect of tin oxide nano particles and heat treatment on decay resistance and physical properties of beech wood (Fagus orientalis

    Directory of Open Access Journals (Sweden)

    Maryam Ghorbani

    2014-11-01

    Full Text Available This research was conducted to investigate the effect of Tin oxide nanoparticles and heat treatment on decay resistance and physical properties of beech wood. Biological and physical test samples were prepared according to EN-113 and ASTM-D4446-05 standards respectively. Samples were classified into 4 groups: control, impregnation with Tin oxide nanoparticles, heat treatment and nano-heat treatment. Impregnation with Tin oxide nano at 5000ppm concentration was carried out in the cylinder according to Bethell method. Then, samples were heated at 140, 160 and 185˚C for 2 and 4 hours. According to results, decay resistance improved with increasing time and temperature of heat treatment. Least weight loss showed 46.39% reduction in nano-heat samples treated at 180˚C for 4 hours in comparison with control at highest weight loss. Nano-heat treated samples demonstrated the maximum amount of water absorption without significant difference with control and nanoparticles treated samples. Increase in heat treatment temperature reduced water absorption so that it is revealed 47.8% reduction in heat treated samples at 180°C for 4h after 24h immersion in water. In nano-heat treated samples at 180˚C for 2h was measured least volume swelling. Volume swelling in nano-treated samples decreased 8.7 and 22.76% after 2 and 24 h immersion in comparison with the control samples respectively.

  12. Numerical Methods for Plate Forming by Line Heating

    DEFF Research Database (Denmark)

    Clausen, Henrik Bisgaard

    2000-01-01

    Line heating is the process of forming originally flat plates into a desired shape by means of heat treatment. Parameter studies are carried out on a finite element model to provide knowledge of how the process behaves with varying heating conditions. For verification purposes, experiments are ca...... are carried out; one set of experiments investigates the actual heat flux distribution from a gas torch and another verifies the validty of the FE calculations. Finally, a method to predict the heating pattern is described....

  13. Methods of designing and manufacturing a heat exchanger for the ...

    African Journals Online (AJOL)

    The article describes the method of calculation, design and manufacture of the the plate heat exchanger for the gas turbine plants with heat recovery. We represented the method of threedimensional calculation, which allowed conducting a virtual experiment and clarifying the design of the heat exchanger for the given ...

  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. Heat resistance of Fe-Al intermetallics in the context of selected heat-resistant and hihg-temperature creep resistant steels

    Directory of Open Access Journals (Sweden)

    P. Baranowski

    2009-04-01

    Full Text Available Results are hereby presented of heat-resistance tests of two Fe3Al and FeAl intermetallic phase-based alloys in the context of St41k-typeboiler steel and 50H21G9N4 high-temperature creep resistant steel. It has been ascertained that heat resistance of the 50H21G9N4 steeland of the Fe3Al and FeAl intermetallic phase-based alloys significantly exceeds that of the boiler steel tested in the air atmosphere and the atmosphere of a flue gas with CO, CO2, SiO2 content alike. Improvement of these properties depends of exposure conditions. The largest differences have been observed when the tests were carried out in temperature 1023 K and in the flue gas atmosphere. The differences have been more and more noticeable as the exposition duration extended. A tendency has been also recorded of smaller mass decrements of the Fe3Al and FeAl intermetallic phase-based alloys as compared to the 50H21G9N4 steel.

  16. A simplified method of calculating heat flow through a two-phase heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Yohanis, Y.G. [Thermal Systems Engineering Group, Faculty of Engineering, University of Ulster, Newtownabbey, Co Antrim, BT37 0QB Northern Ireland (United Kingdom)]. E-mail: yg.yohanis@ulster.ac.uk; Popel, O.S. [Non-traditional Renewable Energy Sources, Institute for High Temperatures, Russian Academy of Sciences, 13/19 Izhorskaya str., IVTAN, Moscow 125412 (Russian Federation); Frid, S.E. [Non-traditional Renewable Energy Sources, Institute for High Temperatures, Russian Academy of Sciences, 13/19 Izhorskaya str., IVTAN, Moscow 125412 (Russian Federation)

    2005-10-01

    A simplified method of calculating the heat flow through a heat exchanger in which one or both heat carrying media are undergoing a phase change is proposed. It is based on enthalpies of the heat carrying media rather than their temperatures. The method enables the determination of the maximum rate of heat flow provided the thermodynamic properties of both heat-carrying media are known. There will be no requirement to separately simulate each part of the system or introduce boundaries within the heat exchanger if one or both heat-carrying media undergo a phase change. The model can be used at the pre-design stage, when the parameters of the heat exchangers may not be known, i.e., to carry out an assessment of a complex energy scheme such as a steam power plant. One such application of this model is in thermal simulation exercises within the TRNSYS modeling environment.

  17. A simplified method of calculating heat flow through a two-phase heat exchanger

    International Nuclear Information System (INIS)

    Yohanis, Y.G.; Popel, O.S.; Frid, S.E.

    2005-01-01

    A simplified method of calculating the heat flow through a heat exchanger in which one or both heat carrying media are undergoing a phase change is proposed. It is based on enthalpies of the heat carrying media rather than their temperatures. The method enables the determination of the maximum rate of heat flow provided the thermodynamic properties of both heat-carrying media are known. There will be no requirement to separately simulate each part of the system or introduce boundaries within the heat exchanger if one or both heat-carrying media undergo a phase change. The model can be used at the pre-design stage, when the parameters of the heat exchangers may not be known, i.e., to carry out an assessment of a complex energy scheme such as a steam power plant. One such application of this model is in thermal simulation exercises within the TRNSYS modeling environment

  18. Thermal contact resistance in carbon nanotube enhanced heat storage materials

    NARCIS (Netherlands)

    Zhang, H.; Nedea, S.V.; Rindt, C.C.M.; Smeulders, D.M.J.

    2015-01-01

    Solid-liquid phase change is one of the most favorable means of compact and economical heat storage in the built environment. In such storage systems, the vast available solar heat is stored as latent heat in the storage materials. Recent studies suggest using sugar alcohols as seasonal heat storage

  19. Ice detection in heat pumps and coolers. [By thermal resistance and capacitance detection

    Energy Technology Data Exchange (ETDEWEB)

    Buick, T R; McMullan, J T; Morgan, R; Murray, R B

    1978-01-01

    Some methods are discussed for detecting the formation of ice on the evaporators of air-source heat pumps and air coolers by electronic means. The sensing of thermal resistance caused by ice build-up can be done by measuring temperature differences between the evaporator and the air, and analyses are presented of the effect of using both linear and non-linear temperature sensors for this purpose. The direct detection of the presence of ice can be done by measuring the capacitance of a suitably-placed pair of plates, and the performance of such a system is analyzed. Preliminary reports are presented of the use of both of these methods of ice detection in the defrosting of an experimental heat pump.

  20. Influence of lactic acid and post-treatment recovery time on the heat resistance of Listeria monocytogenes.

    Science.gov (United States)

    Omori, Yasuo; Miake, Kiyotaka; Nakamura, Hiromi; Kage-Nakadai, Eriko; Nishikawa, Yoshikazu

    2017-09-18

    The aim of this study was to evaluate the effect of lactic acid (LA) with and without organic material at various post-treatment recovery times on the heat resistance of Listeria monocytogenes (Lm). LA decreased Lm numbers; however, the effect was remarkably attenuated by the presence of organic matter. Five strains of Lm were treated with LA and the listericidal effects were compared. The effect of LA varied depending on the strain, with ≥3.0% (w/w) LA required to kill the Lm strains in a short time. The heat resistance of Lm treated with LA was examined with respect to the time interval between the acid treatment and the subsequent manufacturing step. The heat resistance of Lm was shown to significantly increase during the post-treatment period. Heat tolerance (D value) increased up to 3.4-fold compared with the non-treated control bacteria. RNA sequencing and RT-PCR analyses suggested that several stress chaperones, proteins controlled by RecA and associated with high-temperature survival, were involved in the mechanism of enhanced heat resistance. These results are applicable to manufacturers when LA and heat treatment methods are utilized for the effective control of Lm in foods. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Natural convection heat transfer between vertical channel with flow resistance at the lower end

    International Nuclear Information System (INIS)

    Iwamoto, S.; Nishimura, S.; Ishihara, I.

    2003-01-01

    For natural convection in the geometrically complicated channel, the convection flow is suppressed by flow resistance due to such channel itself and the lopsided flow may take place. This could result in serious influences on the heat transfer in the channel. In order to investigate fundamentally the natural convection flow and heat transfer in such the channel, the vertical channel in which wall was heated with uniform heat flux and the flow resistance was given by small clearance between the lower end of channel and a wide horizontal floor. Flow pattern was observed by illuminating smoke filled in the channel and heat transfer rate was measured. (author)

  2. A Simplified Method for Stationary Heat Transfer of a Hollow Core Concrete Slab Used for TABS

    DEFF Research Database (Denmark)

    Yu, Tao; Heiselberg, Per Kvols; Lei, Bo

    2014-01-01

    Thermally activated building systems (TABS) have been an energy efficient way to improve the indoor thermal comfort. Due to the complicated structure, heat transfer prediction for a hollow core concrete used for TABS is difficult. This paper proposes a simplified method using equivalent thermal...... resistance for the stationary heat transfer of this kind of system. Numerical simulations are carried out to validate this method, and this method shows very small deviations from the numerical simulations. Meanwhile, this method is used to investigate the influence of the thickness of insulation on the heat...... transfer. The insulation with a thickness of more than 0.06 m can keep over 95 % of the heat transferred from the lower surface, which is beneficial to the radiant ceiling cooling. Finally, this method is extended to involve the effect of the pipe, and the numerical comparison results show that this method...

  3. The electrical resistivity method in cased boreholes

    Energy Technology Data Exchange (ETDEWEB)

    Schenkel, C.J.

    1991-05-01

    The use of downhole current sources in resistivity mapping can greatly enhance the detection and delineation of subsurface features. The purpose of this work is to examine the resistivity method for current sources in wells cased with steel. The resistivity method in cased boreholes with downhole current sources is investigated using the integral equation (IE) technique. The casing and other bodies are characterized as conductivity inhomogeneities in a half-space. For sources located along the casing axis, an axially symmetric Green's function is used to formulate the surface potential and electric field (E-field) volume integral equations. The situations involving off-axis current sources and three-dimensional (3-D) bodies is formulated using the surface potential IE method. The solution of the 3-D Green's function is presented in cylindrical and Cartesian coordinate systems. The methods of moments is used to solve the Fredholm integral equation of the second kind for the response due to the casing and other bodies. The numerical analysis revealed that the current in the casing can be approximated by its vertical component except near the source and the axial symmetric approximation of the casing is valid even for the 3-D problem. The E-field volume IE method is an effective and efficient technique to simulate the response of the casing in a half-space, whereas the surface potential approach is computationally better when multiple bodies are involved. Analyzing several configurations of the current source indicated that the casing response is influenced by four characteristic factors: conduction length, current source depth,casing depth, and casing length. 85 refs., 133 figs., 11 tabs.

  4. Evaluation of the Internal and Borehole Resistances during Thermal Response Tests and Impact on Ground Heat Exchanger Design

    Directory of Open Access Journals (Sweden)

    Louis Lamarche

    2017-12-01

    Full Text Available The main parameters evaluated with a conventional thermal response test (TRT are the subsurface thermal conductivity surrounding the borehole and the effective borehole thermal resistance, when averaging the inlet and outlet temperature of a ground heat exchanger with the arithmetic mean. This effective resistance depends on two resistances: the 2D borehole resistance (Rb and the 2D internal resistance (Ra which is associated to the short-circuit effect between pipes in the borehole. This paper presents a field method to evaluate these two components separately. Two approaches are proposed. In the first case, the temperature at the bottom of the borehole is measured at the same time as the inlet and outlet temperatures as done in a conventional TRT. In the second case, different flow rates are used during the experiment to infer the internal resistance. Both approaches assumed a predefined temperature profile inside the borehole. The methods were applied to real experimental tests and compared with numerical simulations. Interesting results were found by comparison with theoretical resistances calculated with the multipole method. The motivation for this work is evidenced by analyzing the impact of the internal resistance on a typical geothermal system design. It is shown to be important to know both resistance components to predict the variation of the effective resistance when the flow rate and the height of the boreholes are changed during the design process.

  5. Review of PCMS and heat transfer enhancement methods applied ...

    African Journals Online (AJOL)

    Most available PCMs have low thermal conductivity making heat transfer enhancement necessary for power applications. The various methods of heat transfer enhancement in latent heat storage systems were also reviewed systematically. The review showed that three commercially - available PCMs are suitable in the ...

  6. Measurement of heat transfer coefficient using termoanemometry methods

    Science.gov (United States)

    Dančová, P.; Sitek, P.; Vít, T.

    2014-03-01

    This work deals with a measurement of heat transfer from a heated flat plate on which a synthetic jet impacts perpendicularly. Measurement of a heat transfer coefficient (HTC) is carried out using the hot wire anemometry method with glue film probe Dantec 55M47. The paper brings also results of velocity profiles measurements and turbulence intensity calculations.

  7. Measurement of heat transfer coefficient using termoanemometry methods

    Directory of Open Access Journals (Sweden)

    Dančová P.

    2014-03-01

    Full Text Available This work deals with a measurement of heat transfer from a heated flat plate on which a synthetic jet impacts perpendicularly. Measurement of a heat transfer coefficient (HTC is carried out using the hot wire anemometry method with glue film probe Dantec 55M47. The paper brings also results of velocity profiles measurements and turbulence intensity calculations.

  8. Measurement of Critical Heat Flux Using the Transient Inverse Heat Conduction Method in Spray cooling

    International Nuclear Information System (INIS)

    Kim, Yeung Chan

    2016-01-01

    A study on the measurement of critical heat flux using the transient inverse heat conduction method in spray cooling was performed. The inverse heat conduction method estimates the surface heat flux or temperature using a measured interior temperature history. The effects of the measuring time interval and location of temperature measurement on the measurement of critical heat flux were primarily investigated. The following results were obtained. The estimated critical heat flux decreased as the time interval of temperature measurement increased. Meanwhile, the effect of measurement location on critical heat flux was not significant. It was also found, from the experimental results, that the critical superheat increased as the measurement location of thermocouple neared the heat transfer surface.

  9. Measurement of Critical Heat Flux Using the Transient Inverse Heat Conduction Method in Spray cooling

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeung Chan [Andong Nat’l Univ., Andong (Korea, Republic of)

    2016-10-15

    A study on the measurement of critical heat flux using the transient inverse heat conduction method in spray cooling was performed. The inverse heat conduction method estimates the surface heat flux or temperature using a measured interior temperature history. The effects of the measuring time interval and location of temperature measurement on the measurement of critical heat flux were primarily investigated. The following results were obtained. The estimated critical heat flux decreased as the time interval of temperature measurement increased. Meanwhile, the effect of measurement location on critical heat flux was not significant. It was also found, from the experimental results, that the critical superheat increased as the measurement location of thermocouple neared the heat transfer surface.

  10. Heat-resistant agent used for control sand of steam huff and puff heavy oil well

    Science.gov (United States)

    Zhang, F. S.; Liu, G. L.; Lu, Y. J.; Xiong, X. C.; Ma, J. H.; Su, H. M.

    2018-01-01

    Heat-resistant agent containing hydroxymethyl group was synthesized from coal tar, which has similar structure with phenolic resin and could improve the heat resistance of phenolic resin sand control agent. The results showed that the heat resistance of the sand control agent was improved by adding 10% to 30% heat-resistant agent, after 280°C high temperature treatment for 7d, the compressive strength of consolidated core was increased to more than 5MPa. The compressive strength of consolidation core was not decreased after immersion in formation water, crude oil, acid or alkaline medium, which showed good resistance to medium immersion. The sand control agent had small core damage and the core permeability damage ratio of sand control agent consolidation was only 18.7%.

  11. Method for controlling exhaust gas heat recovery systems in vehicles

    Science.gov (United States)

    Spohn, Brian L.; Claypole, George M.; Starr, Richard D

    2013-06-11

    A method of operating a vehicle including an engine, a transmission, an exhaust gas heat recovery (EGHR) heat exchanger, and an oil-to-water heat exchanger providing selective heat-exchange communication between the engine and transmission. The method includes controlling a two-way valve, which is configured to be set to one of an engine position and a transmission position. The engine position allows heat-exchange communication between the EGHR heat exchanger and the engine, but does not allow heat-exchange communication between the EGHR heat exchanger and the oil-to-water heat exchanger. The transmission position allows heat-exchange communication between the EGHR heat exchanger, the oil-to-water heat exchanger, and the engine. The method also includes monitoring an ambient air temperature and comparing the monitored ambient air temperature to a predetermined cold ambient temperature. If the monitored ambient air temperature is greater than the predetermined cold ambient temperature, the two-way valve is set to the transmission position.

  12. Study of critical dependence of stable phases in Nitinol on heat treatment using electrical resistivity probe

    International Nuclear Information System (INIS)

    Uchil, J.; Mohanchandra, K.P.; Kumara, K.G.; Mahesh, K.K.

    1998-01-01

    Phase transformations in 40% cold-worked Nitinol as a function of heat treatment have been studied using electrical resistivity variation with temperature. The stabilisation of austenitic, rhombohedral and martensitic phases is shown to critically depend on the temperatures of heat treatment by the analysis of temperature dependence of electrical resistivity in heating and cooling parts of the cycle. Characteristic values of electrical resistivity of the stable phases are determined. The R-phase has been found to form continuously with increasing heat-treatment temperature starting from room temperature and to suddenly disappear beyond heat-treatment at 683 K. The observed presence or absence of R-phase is confirmed by heat capacity measurements as a function of temperature. (orig.)

  13. Heat and UV light resistance of vegetative cells and spores of Bacillus subtilis rec-mutants

    International Nuclear Information System (INIS)

    Hanlin, J.H.; Lombardi, S.J.; Slepecky, R.A.

    1985-01-01

    The heat and UV light resistance of spores and vegetative cells of Bacillus subtilis BD170 (rec+) were greater than those of B. subtilis BD224 (recE4). Strain BD170 can repair DNA whereas BD224 is repair deficient due to the presence of the recE4 allele. Spores of a GSY Rec+ strain were more heat resistant than spores of GSY Rec- and Uvr- mutants. The overall level of heat and UV light resistance attained by spores may in part be determined by their ability to repair deoxyribonucleic acid after exposure to these two physical mutagens

  14. Effect of thymol in heating and recovery media on the isothermal and non-isothermal heat resistance of Bacillus spores.

    Science.gov (United States)

    Esteban, Maria-Dolores; Conesa, Raquel; Huertas, Juan-Pablo; Palop, Alfredo

    2015-06-01

    Members of the genus Bacillus include important food-borne pathogen and spoilage microorganisms for food industry. Essential oils are natural products extracted from herbs and spices, which can be used as natural preservatives in many foods because of their antibacterial, antifungal, antioxidant and anti-carcinogenic properties. The aim of this research was to explore the effect of the addition of different concentrations of thymol to the heating and recovery media on the thermal resistance of spores of Bacillus cereus, Bacillus licheniformis and Bacillus subtilis at different temperatures. While the heat resistance was hardly reduced when thymol was present in the heating medium, the effect in the recovery medium was greater, reducing the D100 °C values down to one third for B. subtilis and B. cereus when 0.5 mM thymol was added. This effect was dose dependent and was also observed at other heating temperatures. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Comparison of temperature estimates from heat transport model and electrical resistivity tomography during a shallow heat injection and storage experiment

    OpenAIRE

    Hermans, Thomas; Daoudi, Moubarak; Vandenbohede, Alexander; Robert, Tanguy; Caterina, David; Nguyen, Frédéric

    2012-01-01

    Groundwater resources are increasingly used around the world as geothermal systems. Understanding physical processes and quantification of parameters determining heat transport in porous media is therefore important. Geophysical methods may be useful in order to yield additional information with greater coverage than conventional wells. We report a heat transport study during a shallow heat injection and storage field test. Heated water (about 50°C) was injected for 6 days at the rate of 80 l...

  16. Quantifying variety-specific heat resistance and the potential for adaptation to climate change.

    Science.gov (United States)

    Tack, Jesse; Barkley, Andrew; Rife, Trevor W; Poland, Jesse A; Nalley, Lawton Lanier

    2016-08-01

    The impact of climate change on crop yields has become widely measured; however, the linkages for winter wheat are less studied due to dramatic weather changes during the long growing season that are difficult to model. Recent research suggests significant reductions under warming. A potential adaptation strategy involves the development of heat resistant varieties by breeders, combined with alternative variety selection by producers. However, the impact of heat on specific wheat varieties remains relatively unstudied due to limited data and the complex genetic basis of heat tolerance. Here, we provide a novel econometric approach that combines field-trial data with a genetic cluster mapping to group wheat varieties and estimate a separate extreme heat impact (temperatures over 34 °C) across 24 clusters spanning 197 varieties. We find a wide range of heterogeneous heat resistance and a trade-off between average yield and resistance. Results suggest that recently released varieties are less heat resistant than older varieties, a pattern that also holds for on-farm varieties. Currently released - but not yet adopted - varieties do not offer improved resistance relative to varieties currently grown on farm. Our findings suggest that warming impacts could be significantly reduced through advances in wheat breeding and/or adoption decisions by producers. However, current adaptation-through-adoption potential is limited under a 1 °C warming scenario as increased heat resistance cannot be achieved without a reduction in average yields. © 2015 John Wiley & Sons Ltd.

  17. Wastewater heat recovery method and apparatus

    Science.gov (United States)

    Kronberg, J.W.

    1991-01-01

    This invention is comprised of a heat recovery system with a heat exchanger and a mixing valve. A drain trap includes a heat exchanger with an inner coiled tube, baffle plate, wastewater inlet, wastewater outlet, cold water inlet, and preheated water outlet. Wastewater enters the drain trap through the wastewater inlet, is slowed and spread by the baffle plate, and passes downward to the wastewater outlet. Cold water enters the inner tube through the cold water inlet and flows generally upward, taking on heat from the wastewater. This preheated water is fed to the mixing valve, which includes a flexible yoke to which are attached an adjustable steel rod, two stationary zinc rods, and a pivoting arm. The free end of the arm forms a pad which rests against a valve seat. The rods and pivoting arm expand or contract as the temperature of the incoming preheated water changes. The zinc rods expand more than the steel rod, flexing the yoke and rotating the pivoting arm. The pad moves towards the valve seat as the temperature of the preheated water rises, and away as the temperature falls, admitting a variable amount of hot water to maintain a nearly constant average process water temperature.

  18. Research status and evaluation system of heat source evaluation method for central heating

    Science.gov (United States)

    Sun, Yutong; Qi, Junfeng; Cao, Yi

    2018-02-01

    The central heating boiler room is a regional heat source heating center. It is also a kind of the urban environment pollution, it is an important section of building energy efficiency. This article through to the evaluation method of central heating boiler room and overviews of the researches during domestic and overseas, summarized the main influence factors affecting energy consumption of industrial boiler under the condition of stable operation. According to the principle of establishing evaluation index system. We can find that is great significance in energy saving and environmental protection for the content of the evaluation index system of the centralized heating system.

  19. Combined resistive and laser heating technique for in situ radial X-ray diffraction in the diamond anvil cell at high pressure and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Miyagi, Lowell [Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112 (United States); Department of Earth Sciences, Montana State University, Bozeman, Montana 59717 (United States); Kanitpanyacharoen, Waruntorn; Kaercher, Pamela; Wenk, Hans-Rudolf; Alarcon, Eloisa Zepeda [Department of Earth and Planetary Science, University of California, Berkeley, California 94720 (United States); Raju, Selva Vennila [Advanced Light Source, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States); HiPSEC, Department of Physics, University of Nevada, Las Vegas, Nevada 89154 (United States); Knight, Jason; MacDowell, Alastair [Advanced Light Source, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States); Williams, Quentin [Department of Earth and Planetary Science, University of California, Santa Cruz, California 95064 (United States)

    2013-02-15

    To extend the range of high-temperature, high-pressure studies within the diamond anvil cell, a Liermann-type diamond anvil cell with radial diffraction geometry (rDAC) was redesigned and developed for synchrotron X-ray diffraction experiments at beamline 12.2.2 of the Advanced Light Source. The rDAC, equipped with graphite heating arrays, allows simultaneous resistive and laser heating while the material is subjected to high pressure. The goals are both to extend the temperature range of external (resistive) heating and to produce environments with lower temperature gradients in a simultaneously resistive- and laser-heated rDAC. Three different geomaterials were used as pilot samples to calibrate and optimize conditions for combined resistive and laser heating. For example, in Run1, FeO was loaded in a boron-mica gasket and compressed to 11 GPa then gradually resistively heated to 1007 K (1073 K at the diamond side). The laser heating was further applied to FeO to raise temperature to 2273 K. In Run2, Fe-Ni alloy was compressed to 18 GPa and resistively heated to 1785 K (1973 K at the diamond side). The combined resistive and laser heating was successfully performed again on (Mg{sub 0.9}Fe{sub 0.1})O in Run3. In this instance, the sample was loaded in a boron-kapton gasket, compressed to 29 GPa, resistive-heated up to 1007 K (1073 K at the diamond side), and further simultaneously laser-heated to achieve a temperature in excess of 2273 K at the sample position. Diffraction patterns obtained from the experiments were deconvoluted using the Rietveld method and quantified for lattice preferred orientation of each material under extreme conditions and during phase transformation.

  20. Heat transfer unit and method for prefabricated vessel

    Science.gov (United States)

    Tamburello, David A.; Kesterson, Matthew R; Hardy, Bruce J.

    2017-11-07

    Vessel assemblies, heat transfer units for prefabricated vessels, and methods for heat transfer prefabricated vessel are provided. A heat transfer unit includes a central rod, and a plurality of peripheral rods surrounding the central rod and connected to the central rod. The plurality of peripheral rods are movable between a first collapsed position and a second bowed position, wherein in the second bowed position a midpoint of each of the plurality of peripheral rods is spaced from the central rod relative to in the first position. The heat transfer unit further includes a heat transfer element connected to one of the plurality of peripheral rods.

  1. Heat-resistant organic molecular layer as a joint interface for metal reduction on plastics surfaces

    International Nuclear Information System (INIS)

    Sang, Jing; Aisawa, Sumio; Hirahara, Hidetoshi; Kudo, Takahiro; Mori, Kunio

    2016-01-01

    Graphical abstract: - Highlights: • In situ adsorption behaviors of TES on PA6 surface were clarified by QCM. • Highest adsorption of TES on PA6 was obtained in pH 3 and 0.1 M solution. • Molecular layers of TES with uniform structures were prepared on PA6 surface. • TES layer improved PA6 local heat resistance from 150 °C to 230 °C. • TES molecular layer successfully reduced Ag ion to Ag"0. - Abstract: Heat-resistant organic molecular layers have been fabricated by triazine-based silane coupling agent for metal reduction on plastic surfaces using adsorption method. These molecular layers were used as an interfacial layer between polyamide (PA6) and metal solution to reduce Ag"+ ion to Ag"0. The interfacial behaviors of triazine molecular layer at the interfaces between PA6 and Ag solution were investigated using quartz crystal microbalance (QCM). The kinetics of molecular adsorption on PA6 was investigated by using triazine-based silane coupling agent solutions at different pH and concentration. X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM), and local nano thermal analysis were employed to characterize the surfaces and interfaces. The nano thermal analysis results show that molecular layers of triazine-based silane coupling agent greatly improved heat resistance of PA6 resin from 170 °C up to 230 °C. This research developed an in-depth insight for molecular behaviors of triazine-based silane coupling agent at the PA6 and Ag solution interfaces and should be of significant value for interfacial research between plastics and metal solution in plating industry.

  2. Heat-resistant organic molecular layer as a joint interface for metal reduction on plastics surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Sang, Jing [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Aisawa, Sumio, E-mail: aisawa@iwate-u.ac.jp [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Hirahara, Hidetoshi [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Kudo, Takahiro [Sulfur Chemical Institute, 210, Collabo MIU, 4-3-5, Ueda, Morioka 020-0066 (Japan); Mori, Kunio [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Sulfur Chemical Institute, 210, Collabo MIU, 4-3-5, Ueda, Morioka 020-0066 (Japan)

    2016-04-15

    Graphical abstract: - Highlights: • In situ adsorption behaviors of TES on PA6 surface were clarified by QCM. • Highest adsorption of TES on PA6 was obtained in pH 3 and 0.1 M solution. • Molecular layers of TES with uniform structures were prepared on PA6 surface. • TES layer improved PA6 local heat resistance from 150 °C to 230 °C. • TES molecular layer successfully reduced Ag ion to Ag{sup 0}. - Abstract: Heat-resistant organic molecular layers have been fabricated by triazine-based silane coupling agent for metal reduction on plastic surfaces using adsorption method. These molecular layers were used as an interfacial layer between polyamide (PA6) and metal solution to reduce Ag{sup +} ion to Ag{sup 0}. The interfacial behaviors of triazine molecular layer at the interfaces between PA6 and Ag solution were investigated using quartz crystal microbalance (QCM). The kinetics of molecular adsorption on PA6 was investigated by using triazine-based silane coupling agent solutions at different pH and concentration. X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM), and local nano thermal analysis were employed to characterize the surfaces and interfaces. The nano thermal analysis results show that molecular layers of triazine-based silane coupling agent greatly improved heat resistance of PA6 resin from 170 °C up to 230 °C. This research developed an in-depth insight for molecular behaviors of triazine-based silane coupling agent at the PA6 and Ag solution interfaces and should be of significant value for interfacial research between plastics and metal solution in plating industry.

  3. Non-parametric method for separating domestic hot water heating spikes and space heating

    DEFF Research Database (Denmark)

    Bacher, Peder; de Saint-Aubain, Philip Anton; Christiansen, Lasse Engbo

    2016-01-01

    In this paper a method for separating spikes from a noisy data series, where the data change and evolve over time, is presented. The method is applied on measurements of the total heat load for a single family house. It relies on the fact that the domestic hot water heating is a process generating...

  4. Modeling of electric and heat processes in spot resistance welding of cross-wire steel bars

    Science.gov (United States)

    Iatcheva, Ilona; Darzhanova, Denitsa; Manilova, Marina

    2018-03-01

    The aim of this work is the modeling of coupled electric and heat processes in a system for spot resistance welding of cross-wire reinforced steel bars. The real system geometry, dependences of material properties on the temperature, and changes of contact resistance and released power during the welding process have been taken into account in the study. The 3D analysis of the coupled AC electric and transient thermal field distributions is carried out using the finite element method. The novel feature is that the processes are modeled for several successive time stages, corresponding to the change of contact area, related contact resistance, and reduction of the released power, occurring simultaneously with the creation of contact between the workpieces. The values of contact resistance and power changes have been determined on the basis of preliminary experimental and theoretical investigations. The obtained results present the electric and temperature field distributions in the system. Special attention has been paid to the temperature evolution at specified observation points and lines in the contact area. The obtained information could be useful for clarification of the complicated nature of interrelated electric, thermal, mechanical, and physicochemical welding processes. Adequate modeling is also an opportunity for proper control and improvement of the system.

  5. Numerical Methods for Plate Forming by Line Heating

    DEFF Research Database (Denmark)

    Clausen, Henrik Bisgaard

    2000-01-01

    Few researchers have addressed so far the topic Line Heating in the search for better control of the process. Various methods to help understanding the mechanics have been used, including beam analysis approximation, equivalent force calculation and three-dimensional finite element analysis. I...... consider here finite element methods to model the behaviour and to predict the heating paths....

  6. Application of least-squares method to decay heat evaluation

    International Nuclear Information System (INIS)

    Schmittroth, F.; Schenter, R.E.

    1976-01-01

    Generalized least-squares methods are applied to decay-heat experiments and summation calculations to arrive at evaluated values and uncertainties for the fission-product decay-heat from the thermal fission of 235 U. Emphasis is placed on a proper treatment of both statistical and correlated uncertainties in the least-squares method

  7. Heat resistance study of basalt fiber material via mechanical tests

    Science.gov (United States)

    Gao, Y. Q.; Jia, C.; Meng, L.; Li, X. H.

    2017-12-01

    This paper focuses on the study of the relationship between the fracture strength of basalt rovings and temperature. Strong stretching performance of the rovings has been tested after the treatment at fixed temperatures but different heating time and then the fracture strength of the rovings exposed to the heating at different temperatures and cooled in different modes investigated. Finally, the fracture strength of the basalt material after the heat treatment was studied. The results showed that the room-temperature strength tends to decrease with an increase of the heat treatment time at 250 °C, but it has the local maximum after 2h heating. And the basalt rovings strength increased after the heat treatment up to 200 °C. It was 16.7 percent higher than the original strength. The strength depends not only on the temperature and duration of the heating, but also on the cooling mode. The value of the strength measured after cold water cooling was less by 6.3% compared with an ambient air cooling mode. The room-temperature breaking strength of the rovings heated at 200 °C and 100 °C for 2 hours each increased by about 14.6% with respect to unpretreated basalt rovings.

  8. Method and means for determining heat quantities

    Energy Technology Data Exchange (ETDEWEB)

    Waasdorp, G G; de Jong, J J; Bijl, A

    1965-08-24

    To determine the quantity of potential heat W that has flowed past a certain point in a certain time, the velocity of the combustible Q, the temperature T, and the specific gravity YDTU are measured, and these values are transmitted to a computer which automatically calculates the quantity: ..pi..EQUATION/sup -/ in which delta T is the difference between the combustible temperature T and a reference temperature, and in which the relation f(YDTU, delta T) represents the heat of combustion as a function of the quantities YDTU and delta T and possibly other properties of the combustible. Alternatively the quantity: ..pi..EQUATION/sup -/ may be measured; here the quantities have the same meaning as above.

  9. Effect of Ultrasonic Waves on the Heat Resistance of Bacillus cereus and Bacillus licheniformis Spores

    Science.gov (United States)

    Burgos, J.; Ordóñez, J. A.; Sala, F.

    1972-01-01

    Heat resistance of Bacillus cereus and Bacillus licheniformis spores in quarter-strength Ringer solution decreases markedly after ultrasonic treatments which are unable to kill a significant proportion of the spore population. This effect does not seem to be caused by a loss of Ca2+ or dipicolinic acid. The use of ultrasonics to eliminate vegetative cells or to break aggregates in Bacillus spore suspensions to be used subsequently in heat resistance experiments appears to be unadvisable. PMID:4627969

  10. Developmental acclimation to low or high humidity conditions affect starvation and heat resistance of Drosophila melanogaster.

    Science.gov (United States)

    Parkash, Ravi; Ranga, Poonam; Aggarwal, Dau Dayal

    2014-09-01

    Several Drosophila species originating from tropical humid localities are more resistant to starvation and heat stress than populations from high latitudes but mechanistic bases of such physiological changes are largely unknown. In order to test whether humidity levels affect starvation and heat resistance, we investigated developmental acclimation effects of low to high humidity conditions on the storage and utilization of energy resources, body mass, starvation survival, heat knockdown and heat survival of D. melanogaster. Isofemale lines reared under higher humidity (85% RH) stored significantly higher level of lipids and showed greater starvation survival hours but smaller in body size. In contrast, lines reared at low humidity evidenced reduced levels of body lipids and starvation resistance. Starvation resistance and lipid storage level were higher in females than males. However, the rate of utilization of lipids under starvation stress was lower for lines reared under higher humidity. Adult flies of lines reared at 65% RH and acclimated under high or low humidity condition for 200 hours also showed changes in resistance to starvation and heat but such effects were significantly lower as compared with developmental acclimation. Isofemale lines reared under higher humidity showed greater heat knockdown time and heat-shock survival. These laboratory observations on developmental and adult acclimation effects of low versus high humidity conditions have helped in explaining seasonal changes in resistance to starvation and heat of the wild-caught flies of D. melanogaster. Thus, we may suggest that wet versus drier conditions significantly affect starvation and heat resistance of D. melanogaster. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Heat exchangers and methods of construction thereof

    International Nuclear Information System (INIS)

    Schluderberg, D.C.

    1988-01-01

    A heat exchanger is described comprising a shell having first inlet means and first outlet means for the flow of a first fluid therethrough, a plurality of tubes within the shell to provide a path for flow of a second fluid in heat exchange relation to the first fluid, second inlet means and second outlet means for flow of the second fluid to and from the tubes respectively, a tubular member concentric with at least a portion of the length of one of the tubes to define a space between the tube and the tubular member, at least one radially outwardly projecting portion on the tubular member, and a plurality of tube support means spaced apart and disposed generally perpendicular to the tube axes, wherein the tubular member is fixedly attached at one end to one of the tube support means and at the other end to an adjacent one of the tube support means, the space between the tube and the tubular member is closed to flow of both the first fluid and the second fluid, and the radially outwardly projecting portion on the tubular member extends longitudinally to allow flexing of the tubular member and expanding thereof radially outwardly during construction of the heat exchanger so as to allow insertion of the tube into the tubular member, the radially outwardly projecting portion defining a gap which contributes to the space between the tube and the tubular member. 6 figs

  12. THE INFLUENCE OF THE FILLER GRAIN COMPOSITION ON THE PROPERTIES OF THE HEAT-RESISTANT BASALTIC CONCRETE

    Directory of Open Access Journals (Sweden)

    A. M. Gadzhiev

    2017-01-01

    Full Text Available Objectives. The optimal granulometric composition of filler compound ensures the production of concrete having improved  physical and mechanical characteristics, as well as minimal binder  consumption. The properties of heat-resistant concrete largely  depend on the type and the ratio of its components. Taking this into  account, the aim of the study is to determine the optimal grain composition of heat-resistant concrete.Methods. Methods for optimising the properties of heatresistant basaltic concrete with a composite binder and  mechanochemical activation of the filler grains were used during the  course of the research.A simplex-centroid experiment design is  applied for this purpose. The composite binder was subjected to  mechanochemical activation. Samples were made by vibration-pressing from a concrete mix with a cone draught of 2 cm.Results. The grain composition of heat-resistant concrete is proved  to be the most important variable factor, regulating which the  properties of concrete can be varied. The compositions of heat- resistant basaltic concrete with activated composite binder having a  maximum application temperature of 700 ºС are developed. The  influence of the grain composition of the basaltic filler on the  properties of basaltic concrete using mathematical experiment planning methods is determined. The regression equations for the ultimate tensile strength and bending stress of basaltic concrete are  obtained for heating temperature of 700ºC.Conclusion. The granulometric composition of heat-resistant basaltic concrete based on the activated binder is optimised for basic physical and technical properties. The optimal granulometric  design of the composition of heat-resistant concrete indicates that as the coarse fraction (particles greater than 0.63 mm in the filler  composition increases, the ultimate tensile strength and bending  stress of heatresistant basaltic concrete is increased

  13. Thermophysical data for various transition metals at high temperatures obtained by a submicrosecond-pulse-heating method

    International Nuclear Information System (INIS)

    Seydel, U.; Bauhof, H.; Fucke, W.; Wadle, H.

    1979-01-01

    Thermophysical data for several transition metals are reported including enthalpies, electric resistivities, and specific volumes at the melting transition, and volume expansion coefficients and heat capacities in the liquid phase. Values for the critical temperatures, pressures, and volumes are given for molybdenum and tungsten. All data have been obtained by a submicrosecond-pulse-heating method. (author)

  14. Stainless steel welding method with excellent nitric acid corrosion resistance

    International Nuclear Information System (INIS)

    Matsushita, Yukinobu; Inazumi, Toru; Hyakubo, Tamako; Masamura, Katsumi.

    1996-01-01

    The present invention concerns a welding method for a stainless steel used in a circumstance being in contact with a highly oxidizing nitric acid solution such as nuclear fuel reprocessing facilities, upon welding 316 type austenite steel containing Mo while giving excellent nitric acid resistance. A method of TIG welding using a filler metal having a composition of C, Si, Mn, P, S, Ni, Cr, Mo and Cu somewhat different from a stainless steel mother material in which C, Si, Mn, P, S, Ni, Cr and Mo are specified comprises a step of TIG-welding the surface of the mother material and a step of TIG-welding the rear face of the mother material, in which the welding conditions for the rear face of the mother material are such that the distance between the surface of the outermost welding metal layer on the side of the surface of the mother material and the bottom of the groove is not less than 5mm, and an amount of welding heat is made constant. As a result, even if the method is used in a circumstance being in contact with a highly corrosive solution such as nitric acid, corrosion resistance is not degraded. (N.H.)

  15. Evaluating parameterizations of aerodynamic resistance to heat transfer using field measurements

    Directory of Open Access Journals (Sweden)

    Shaomin Liu

    2007-01-01

    Full Text Available Parameterizations of aerodynamic resistance to heat and water transfer have a significant impact on the accuracy of models of land – atmosphere interactions and of estimated surface fluxes using spectro-radiometric data collected from aircrafts and satellites. We have used measurements from an eddy correlation system to derive the aerodynamic resistance to heat transfer over a bare soil surface as well as over a maize canopy. Diurnal variations of aerodynamic resistance have been analyzed. The results showed that the diurnal variation of aerodynamic resistance during daytime (07:00 h–18:00 h was significant for both the bare soil surface and the maize canopy although the range of variation was limited. Based on the measurements made by the eddy correlation system, a comprehensive evaluation of eight popularly used parameterization schemes of aerodynamic resistance was carried out. The roughness length for heat transfer is a crucial parameter in the estimation of aerodynamic resistance to heat transfer and can neither be taken as a constant nor be neglected. Comparing with the measurements, the parameterizations by Choudhury et al. (1986, Viney (1991, Yang et al. (2001 and the modified forms of Verma et al. (1976 and Mahrt and Ek (1984 by inclusion of roughness length for heat transfer gave good agreements with the measurements, while the parameterizations by Hatfield et al. (1983 and Xie (1988 showed larger errors even though the roughness length for heat transfer has been taken into account.

  16. Influence of Heat Treatments on the Corrosion Resistance of Medium -Carbon Steel using Sulfuric Spring Water

    Directory of Open Access Journals (Sweden)

    Ikhlas Basheer

    2015-02-01

    Full Text Available The corrosion is one of the important problems that may be occur to the parts of machinery and equipment after manufactured and when used as a result of exposure to corrosive media. Plain-carbon steel is considered as one of the most common minerals used in industrial applications. Some of heat treatments can have direct effect on the corrosion rate of steel by building up galvanic corrosion cells between its microscopic phases. Therefore, to adopt one of kinds of the plain-carbon steel and the most commonly used in industry to be study subject, that is medium carbon steel and took samples of this steel has been treated thermally in three methods which the normalising, annealing, and hardening .The corrosive media used in the research is Sulfuric Spring, it contains many chemical compounds to show its influence on the corrosion of steel. The weight loss method is used to determine corrosion rate and to compare between the results obtained, show that the greatest corrosion resistance of the annealed steel and the corrosion resistance of the hardened steel is the lowest while the corrosion  resistance of the normalised steel is in-between them.         Calcium carbonate was formed on the metal surface which acts as an isolating layer which decrease corrosion rate with time

  17. Simulation of Radiation Heat Transfer in a VAR Furnace Using an Electrical Resistance Network

    Science.gov (United States)

    Ballantyne, A. Stewart

    The use of electrical resistance networks to simulate heat transfer is a well known analytical technique that greatly simplifies the solution of radiation heat transfer problems. In a VAR furnace, radiative heat transfer occurs between the ingot, electrode, and crucible wall; and the arc when the latter is present during melting. To explore the relative heat exchange between these elements, a resistive network model was developed to simulate the heat exchange between the electrode, ingot, and crucible with and without the presence of an arc. This model was then combined with an ingot model to simulate the VAR process and permit a comparison between calculated and observed results during steady state melting. Results from simulations of a variety of alloys of different sizes have demonstrated the validity of the model. Subsequent simulations demonstrate the application of the model to the optimization of both steady state and hot top melt practices, and raises questions concerning heat flux assumptions at the ingot top surface.

  18. Improved corrosion resistance of aluminum brazing sheet by a post-brazing heat treatment

    NARCIS (Netherlands)

    Norouzi Afshar, F.; Tichelaar, F.D.; Glenn, A. M.; Taheri, P.; Sababi, M.; Terryn, H.A.; Mol, J.M.C.

    2017-01-01

    This work studies the influence of the microstructure on the corrosion mechanism and susceptibility of as-brazed aluminum sheet. Various microstructures are obtained using postbrazing heat treatments developed to enhance the corrosion resistance of an AA4xxx/AA3xxx brazing sheet. The heat

  19. A review of the cylindrical heat source method for the design and analysis of vertical ground-coupled heat pump systems

    Energy Technology Data Exchange (ETDEWEB)

    Bernier, M. [Ecole Polytechnique, Montreal, PQ (Canada). Dept. de Genie Mecanique

    2000-12-01

    The successful design and analysis of ground-coupled heat pump (GCHP) systems depends in large part on the adequate prediction of ground water heat transfer. The author presented a detailed review of the cylindrical heat source method utilized for the prediction of transient heat transfer in vertical U-tube ground heat exchangers. The physics that underlies the theory applicable to this technology is explained in a step-by-step manner. Explanations are also provided for the equations that govern the determination of design lengths for the cylindrical heat method, as presented in the ASHRAE handbook. Some improvements were recommended by the author, such as the calculation of the effective thermal resistances using the borehole diameter instead of the equivalent U-tube diameter now in use. Annual hour-by-hour building load calculations should be used to calculate ground loads. 8 refs., 2 tabs., 5 figs., 3 appendices.

  20. Heat stress in chemical protective clothing: Porosity and vapour resistance

    NARCIS (Netherlands)

    Havenith, G.; Hartog, E.A. den; Martini, S.

    2011-01-01

    Heat strain in chemical protective clothing is an important factor in industrial and military practice. Various improvements to the clothing to alleviate strain while maintaining protection have been attempted. More recently, selectively permeable membranes have been introduced to improve

  1. Comparison of Several Methods for Determining the Internal Resistance of Lithium Ion Cells

    Directory of Open Access Journals (Sweden)

    Hans-Georg Schweiger

    2010-06-01

    Full Text Available The internal resistance is the key parameter for determining power, energy efficiency and lost heat of a lithium ion cell. Precise knowledge of this value is vital for designing battery systems for automotive applications. Internal resistance of a cell was determined by current step methods, AC (alternating current methods, electrochemical impedance spectroscopy and thermal loss methods. The outcomes of these measurements have been compared with each other. If charge or discharge of the cell is limited, current step methods provide the same results as energy loss methods.

  2. Thickness and fit of mouthguards according to heating methods.

    Science.gov (United States)

    Mizuhashi, Fumi; Koide, Kaoru; Takahashi, Mutsumi

    2014-02-01

    The purpose of this study was to examine the difference in the thickness and fit of mouthguards made by four different heating methods of the mouthguard sheet material. A Sports Mouthguard(®) of 3.8-mm thickness was used in this study. Four heating methods were performed. In one method, the sheet was heated only one side. In the other methods, one side of the sheet was heated first until the center of the sheet was displaced by 0.5 cm, 1.0 cm, and 1.5 cm from the baseline, and then turned upside down and heated. The sheets were adapted using a vacuum former when the heated sheets hung 1.5 cm from the baseline. We measured the thickness and fit of the mouthguard at the areas of the central incisor and first molar. The difference in thickness at the central incisor and first molar regions was analyzed by two-way anova. The difference in fit with different heating methods was analyzed by one-way anova. The results showed that the thickness of the mouthguard differed in the central incisor and first molar areas (P heating methods. The fit of the mouthguard at the central incisor and first molar areas was significantly different among the heating methods (P heated surface of the sheet contacted the surface of the working model. This finding may help to fabricate accurate mouthguards. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. METHOD OF CALCULATING THE OPTIMAL HEAT EMISSION GEOTHERMAL WELLS

    Directory of Open Access Journals (Sweden)

    A. I. Akaev

    2015-01-01

    Full Text Available This paper presents a simplified method of calculating the optimal regimes of the fountain and the pumping exploitation of geothermal wells, reducing scaling and corrosion during operation. Comparative characteristics to quantify the heat of formation for these methods of operation under the same pressure at the wellhead. The problem is solved graphic-analytical method based on a balance of pressure in the well with the heat pump. 

  4. Estimation of work capacity of welded mounting joints of pipelines of heat resisting steel

    International Nuclear Information System (INIS)

    Gorynin, I.V.; Ignatov, V.A.; Timofeev, B.T.; Blyumin, A.A.

    1982-01-01

    The analysis of a work capacity of circular welds made for the Dsub(y)850 pipeline connection with high pressure vessels of heat resisting steel of the 15Kh1NMFA type has been carried out on the base of test results with small samples and real units. Welds were performed using the manual electric arc welding without the following heat treatment. It has been shown that residual stresses in such welds do not produce an essential effect on the resistance of weld metal and heat affected zone on the formation and developments of cracks

  5. New progress in the theory and practice of heat-resisting concretes

    International Nuclear Information System (INIS)

    Nekrasov, K.D.

    1975-01-01

    The main properties of heat-resistant cellular, light and heavy concretes based on high-alumina-, alumina- and Portland cements, liquid glass, alumo-phosphate binder and other binding materials containing different fine-ground additives and fillers are considered. The data of foreign and national investigations are presented concerning the effect of heating and mineral composition of cements and fine-ground mineral additions on the phase composition and structure of the cement stone and tensile properties of concretes. The foreign and national experience in the utilization of heat-resistant concretes when constructing thermal units in various branches of industry is described, as well as the economic effectiveness obtained herewith

  6. Influence of heating rate on corrosion behavior of Ni-base heat resistant alloys in simulated VHTR helium environment

    International Nuclear Information System (INIS)

    Kurata, Yuji; Kondo, Tatsuo

    1985-04-01

    The influence of heating rate on corrosion and carbon transfer was studied for Ni-base heat resistant alloys exposed to simulated VHTR(very high temperature reactor) coolant environment. Special attention was focused to relationship between oxidation and carburization at early stage of exposure. Tests were conducted on two heats of Hastelloy XR with different boron(B) content and the developmental alloys, 113MA and KSN. Two kinds of heating rates, i.e. 80 0 C/min and 2 0 C/min, were employed. Corrosion tests were carried out at 900 0 C up to 500 h in JAERI Type B helium, one of the simulated VHTR primary coolant specifications. Under higher heating rate, oxidation resistance of both heats of Hastelloy XR(2.8 ppmB and 40 ppmB) were equivalent and among the best, then KSN and 113MA followed in the order. Under lower heating rate only alloy, i.e. Hastelloy XR with 2.8 ppmB, showed some deteriorated oxidation resistance while all others being unaffected by the heating rate. On the other hand the carbon transfer behavior showed strong dependence on the heating rate. In case of higher heating rate, significant carburization occured at early stage of exposure and thereafter the progress of carburization was slow in all the alloys. On the other hand only slow carburization was the case throughout the exposure in case of lower heating rate. The carburization in VHTR helium environment was interpreted as to be affected by oxide film formation in the early stage of exposure. The carbon pick-up was largest in Hastelloy XR with 40 ppmB and it was followed by Hastelloy XR with 2.8 ppmB. 113MA and KSN were carburized only slightly. The observed difference of carbon pick-up among the alloys tested was interpreted to be attributed mainly to the difference of the carbon activity, the carbide precipitation characteristics among the alloys tested. (author)

  7. Heat release from wood wall assemblies using oxygen consumption method

    Science.gov (United States)

    Hao C. Tran; Robert E. White

    1990-01-01

    The concept of heat release rate is gaining acceptance in the evaluation of fire performance of materials and assemblies. However, this concept has not been incorporated into fire endurance testing such as the ASTM E-119 test method. Heat release rate of assemblies can be useful in determining the time at which the assemblies start to contribute to the controlled fire...

  8. Method of extracting heat from dry geothermal reservoirs

    Science.gov (United States)

    Potter, R.M.; Robinson, E.S.; Smith, M.C.

    1974-01-22

    Hydraulic fracturing is used to interconnect two or more holes that penetrate a previously dry geothermal reservoir, and to produce within the reservoir a sufficiently large heat-transfer surface so that heat can be extracted from the reservoir at a usefully high rate by a fluid entering it through one hole and leaving it through another. Introduction of a fluid into the reservoir to remove heat from it and establishment of natural (unpumped) convective circulation through the reservoir to accomplish continuous heat removal are important and novel features of the method. (auth)

  9. Functional Analysis of Genes Comprising the Locus of Heat Resistance in Escherichia coli.

    Science.gov (United States)

    Mercer, Ryan; Nguyen, Oanh; Ou, Qixing; McMullen, Lynn; Gänzle, Michael G

    2017-10-15

    The locus of heat resistance (LHR) is a 15- to 19-kb genomic island conferring exceptional heat resistance to organisms in the family Enterobacteriaceae , including pathogenic strains of Salmonella enterica and Escherichia coli The complement of LHR-comprising genes that is necessary for heat resistance and the stress-induced or growth-phase-induced expression of LHR-comprising genes are unknown. This study determined the contribution of the seven LHR-comprising genes yfdX1 GI , yfdX2 , hdeD GI , orf11 , trx GI , kefB , and psiE GI by comparing the heat resistances of E. coli strains harboring plasmid-encoded derivatives of the different LHRs in these genes. (Genes carry a subscript "GI" [genomic island] if an ortholog of the same gene is present in genomes of E. coli ) LHR-encoded heat shock proteins sHSP20, ClpK GI , and sHSP GI are not sufficient for the heat resistance phenotype; YfdX1, YfdX2, and HdeD are necessary to complement the LHR heat shock proteins and to impart a high level of resistance. Deletion of trx GI , kefB , and psiE GI from plasmid-encoded copies of the LHR did not significantly affect heat resistance. The effect of the growth phase and the NaCl concentration on expression from the putative LHR promoter p2 was determined by quantitative reverse transcription-PCR and by a plasmid-encoded p2:GFP promoter fusion. The expression levels of exponential- and stationary-phase E. coli cells were not significantly different, but the addition of 1% NaCl significantly increased LHR expression. Remarkably, LHR expression in E. coli was dependent on a chromosomal copy of evgA In conclusion, this study improved our understanding of the genes required for exceptional heat resistance in E. coli and factors that increase their expression in food. IMPORTANCE The locus of heat resistance (LHR) is a genomic island conferring exceptional heat resistance to several foodborne pathogens. The exceptional level of heat resistance provided by the LHR questions the

  10. Quantitative method for measuring heat flux emitted from a cryogenic object

    Science.gov (United States)

    Duncan, R.V.

    1993-03-16

    The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infrared sensing devices.

  11. Quantitative method for measuring heat flux emitted from a cryogenic object

    International Nuclear Information System (INIS)

    Duncan, R.V.

    1993-01-01

    The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infrared sensing devices

  12. Radioactive heat source and method of making same

    International Nuclear Information System (INIS)

    Elsner, N.B.

    1977-01-01

    A radioactive source of heat which is resistant to cremation conditions is made by encapsulating a radioisotope within a containment vessel and forming a refractory metal silicide diffusion coating exterior thereof. A secondary molybdenum vessel may be provided with a molybdenum silicide coating and then heated in air to oxidize its outer layer. A layer is applied exterior of the diffusion-coating which provides a continuous ceramic oxide layer upon subjection to cremation. This outer layer may be discrete silica carried in a hardenable binder of an organic polymer, and a minor amount of antimony is preferably also included

  13. The Ion Cyclotron, Lower Hybrid, and Alfven Wave Heating Methods

    International Nuclear Information System (INIS)

    Koch, R.

    2004-01-01

    This lecture covers the practical features and experimental results of the three heating methods. The emphasis is on ion cyclotron heating. First, we briefly come back to the main non-collisional heating mechanisms and to the particular features of the quasilinear coefficient in the ion cyclotron range of frequencies (ICRF). The specific case of the ion-ion hybrid resonance is treated, as well as the polarisation issue and minority heating scheme. The various ICRF scenarios are reviewed. The experimental applications of ion cyclotron resonance heating (ICRH) systems are outlined. Then, the lower hybrid and Alfven wave heating and current drive experimental results are covered more briefly. Where applicable, the prospects for ITER are commented

  14. Electro-thermo-mechanical coupling analysis of deep drawing with resistance heating for aluminum matrix composites sheet

    Science.gov (United States)

    Zhang, Kaifeng; Zhang, Tuoda; Wang, Bo

    2013-05-01

    Recently, electro-plastic forming to be a focus of attention in materials hot processing research area, because it is a sort of energy-saving, high efficient and green manufacturing technology. An electro-thermo-mechanical model can be adopted to carry out the sequence simulation of aluminum matrix composites sheet deep drawing via electro-thermal coupling and thermal-mechanical coupling method. The first step of process is resistance heating of sheet, then turn off the power, and the second step is deep drawing. Temperature distribution of SiCp/2024Al composite sheet by resistance heating and sheet deep drawing deformation were analyzed. During the simulation, effect of contact resistances, temperature coefficient of resistance for electrode material and SiCp/2024Al composite on temperature distribution were integrally considered. The simulation results demonstrate that Sicp/2024Al composite sheet can be rapidly heated to 400° in 30s using resistances heating and the sheet temperature can be controlled by adjusting the current density. Physical properties of the electrode materials can significantly affect the composite sheet temperature distribution. The temperature difference between the center and the side of the sheet is proportional to the thermal conductivity of the electrode, the principal cause of which is that the heat transfers from the sheet to the electrode. SiCp/2024Al thin-wall part can be intactly manufactured at strain rate of 0.08s-1 and the sheet thickness thinning rate is limited within 20%, which corresponds well to the experimental result.

  15. Influence of Heat Treatment on Mercury Cavitation Resistance of Surface Hardened 316LN Stainless Steel

    Energy Technology Data Exchange (ETDEWEB)

    Pawel, Steven J [ORNL; Hsu, Julia [Massachusetts Institute of Technology (MIT)

    2010-11-01

    The cavitation-erosion resistance of carburized 316LN stainless steel was significantly degraded but not destroyed by heat treatment in the temperature range 500-800 C. The heat treatments caused rejection of some carbon from the carburized layer into an amorphous film that formed on each specimen surface. Further, the heat treatments encouraged carbide precipitation and reduced hardness within the carburized layer, but the overall change did not reduce surface hardness fully to the level of untreated material. Heat treatments as short as 10 min at 650 C substantially reduced cavitation-erosion resistance in mercury, while heat treatments at 500 and 800 C were found to be somewhat less detrimental. Overall, the results suggest that modest thermal excursions perhaps the result of a weld made at some distance to the carburized material or a brief stress relief treatment will not render the hardened layer completely ineffective but should be avoided to the greatest extent possible.

  16. Two distinct groups within the Bacillus subtilis group display significantly different spore heat resistance properties.

    Science.gov (United States)

    Berendsen, Erwin M; Zwietering, Marcel H; Kuipers, Oscar P; Wells-Bennik, Marjon H J

    2015-02-01

    The survival of bacterial spores after heat treatment and the subsequent germination and outgrowth in a food product can lead to spoilage of the food product and economical losses. Prediction of time-temperature conditions that lead to sufficient inactivation requires access to detailed spore thermal inactivation kinetics of relevant model strains. In this study, the thermal inactivation kinetics of spores of fourteen strains belonging to the Bacillus subtilis group were determined in detail, using both batch heating in capillary tubes and continuous flow heating in a micro heater. The inactivation data were fitted using a log linear model. Based on the spore heat resistance data, two distinct groups (p subtilis group could be identified. One group of strains had spores with an average D120 °C of 0.33 s, while the spores of the other group displayed significantly higher heat resistances, with an average D120 °C of 45.7 s. When comparing spore inactivation data obtained using batch- and continuous flow heating, the z-values were significantly different, hence extrapolation from one system to the other was not justified. This study clearly shows that heat resistances of spores from different strains in the B. subtilis group can vary greatly. Strains can be separated into two groups, to which different spore heat inactivation kinetics apply. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Heat-balance integral method for heat transfer in superfluid helium

    Directory of Open Access Journals (Sweden)

    Baudouy Bertrand

    2009-01-01

    Full Text Available The heat-balance integral method is used to solve the non-linear heat diffusion equation in static turbulent superfluid helium (He II. Although this is an approximate method, it has proven that it gives solutions with fairly good accuracy in non-linear fluid dynamics and heat transfer. Using this method, it has been possible to develop predictive solutions that reproduce analytical solution and experimental data. We present the solutions of the clamped heat flux case and the clamped temperature case in a semi-infinite using independent variable transformation to take account of temperature dependency of the thermophysical properties. Good accuracy is obtained using the Kirchhoff transform whereas the method fails with the Goodman transform for larger temperature range.

  18. A new surface resistance measurement method with ultrahigh sensitivity

    International Nuclear Information System (INIS)

    Liang, Changnian.

    1993-01-01

    A superconducting niobium triaxial cavity has been designed and fabricated to study residual surface resistance of planar superconducting materials. The edge of a 25.4 mm or larger diameter sample in the triaxial cavity is located outside the strong field region. Therefore, the edge effects and possible losses between the thin film and the substrate have been minimized, ensuring that induced RF losses are intrinsic to the test material. The fundamental resonant frequency of the cavity is the same as the working frequency of CEBAF cavities. The cavity has a compact size compared to its TE 011 counterpart, which makes it more sensitive to the sample's loss. For even higher sensitivity, a calorimetry method has been used to measure the RF losses on the superconducting sample. At 2 K, a 2 μK temperature change can be resolved by using carbon resistor sensors. The temperature distribution caused by RF heating is measured by 16 carbon composition resistor sensors. A 0.05 μW heating power can be detected as such a resolution, which translates to a surface resistance of 0.02 nΩ at a surface magnetic field of 52 Oe. This is the most sensitive device for surface resistance measurements to date. In addition, losses due to the indium seal, coupling probes, field emission sites other than the sample, and all of the high field resonator surface, are excluded in the measurement. Surface resistance of both niobium and high-Tc superconducting thin films has been measured. A low R s of 35.2 μΩ was measured for a 25.4 mm diameter YBa 2 Cu 3 O 7 thin film at 1.5 GHz and at 2 K. The measurement result is the first result for a large area epitaxially grown thin film sample at such a low RF frequency. The abrupt disappearance of multipacting between two parallel plates has been observed and monitored with the 16 temperature mapping sensors. Field emission or some field dependent anomalous RF losses on the niobium plate have also been observed

  19. Molecular Methods for Detection of Antimicrobial Resistance

    DEFF Research Database (Denmark)

    Anjum, Muna F.; Zankari, Ea; Hasman, Henrik

    2017-01-01

    The increase in bacteria harboring antimicrobial resistance (AMR) is a global problem because there is a paucity of antibiotics available to treat multidrug-resistant bacterial infections in humans and animals. Detection of AMR present in bacteria that may pose a threat to veterinary and public...

  20. Extreme Heat Resistance of Food Borne Pathogens Campylobacter jejuni, Escherichia coli, and Salmonella typhimurium on Chicken Breast Fillet during Cooking

    DEFF Research Database (Denmark)

    de Jong, Aarieke E I; van Asselt, Esther D; Zwietering, Marcel H

    2012-01-01

    cooking enlarged the heat resistance of the food borne pathogens. Additionally, a high challenge temperature or fast heating rate contributed to the level of heat resistance. The data were used to assess the probability of illness (campylobacteriosis) due to consumption of chicken fillet as a function...

  1. The heat shock protein/chaperone network and multiple stress resistance

    KAUST Repository

    Jacob, Pierre

    2016-11-15

    Crop yield has been greatly enhanced during the last century. However, most elite cultivars are adapted to temperate climates and are not well suited to more stressful conditions. In the context of climate change, stress resistance is a major concern. To overcome these difficulties, scientists may help breeders by providing genetic markers associated with stress resistance. However, multi-stress resistance cannot be obtained from the simple addition of single stress resistance traits. In the field, stresses are unpredictable and several may occur at once. Consequently, the use of single stress resistance traits is often inadequate. Although it has been historically linked with the heat stress response, the heat shock protein (HSP)/chaperone network is a major component of multiple stress responses. Among the HSP/chaperone

  2. The heat shock protein/chaperone network and multiple stress resistance

    KAUST Repository

    Jacob, Pierre; Hirt, Heribert; Bendahmane, Abdelhafid

    2016-01-01

    Crop yield has been greatly enhanced during the last century. However, most elite cultivars are adapted to temperate climates and are not well suited to more stressful conditions. In the context of climate change, stress resistance is a major concern. To overcome these difficulties, scientists may help breeders by providing genetic markers associated with stress resistance. However, multi-stress resistance cannot be obtained from the simple addition of single stress resistance traits. In the field, stresses are unpredictable and several may occur at once. Consequently, the use of single stress resistance traits is often inadequate. Although it has been historically linked with the heat stress response, the heat shock protein (HSP)/chaperone network is a major component of multiple stress responses. Among the HSP/chaperone

  3. Does Resistance to Buprofezin Improve Heat and Cold Tolerance of Laodelphax striatellus (Hemiptera: Delphacidae)?

    Science.gov (United States)

    Li, Yongteng; Zhang, Yueliang; Liu, Xiangdong; Guo, Huifang

    2017-08-01

    There is ample evidence that insecticide resistance causes fitness costs and benefits in pests, while the impact of insecticide resistance on thermotolerance of pests is mostly unclear. The Laodelphax striatellus (Fallén), is an important rice insect pest, which has developed resistance to buprofezin in China. Here, we investigated differences in heat tolerance and cold tolerance among L. striatellus lines with variable buprofezin resistance. The lethal time for 50% of the individuals to die (LT50) at 40 °C increased with an increase in buprofezin resistance level, whereas both the survival rate under -22 °C and the supercooling point of planthoppers did not differ significantly between resistant and susceptible strains. The metabolic enzyme carboxylesterase was found to have an association with buprofezin resistance. Our research showed that buprofezin resistance was positively related with heat tolerance in L. striatellus, but it had no effect on cold tolerance. Insecticide resistance in L. striatellus may therefore have broader implications for the ecology of L. striatellus, and the management of buprofezin resistance in this pest may be challenging. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Comparison of two solution ways of district heating control: Using analysis methods, using artificial intelligence methods

    Energy Technology Data Exchange (ETDEWEB)

    Balate, J.; Sysala, T. [Technical Univ., Zlin (Czech Republic). Dept. of Automation and Control Technology

    1997-12-31

    The District Heating Systems - DHS (Centralized Heat Supply Systems - CHSS) are being developed in large cities in accordance with their growth. The systems are formed by enlarging networks of heat distribution to consumers and at the same time they interconnect the heat sources gradually built. The heat is distributed to the consumers through the circular networks, that are supplied by several cooperating heat sources, that means by power and heating plants and heating plants. The complicated process of heat production technology and supply requires the system approach when solving the concept of automatized control. The paper deals with comparison of the solution way using the analysis methods and using the artificial intelligence methods. (orig.)

  5. Biotechnological Methods for Precise Diagnosis of Methicillin Resistance in Staphylococci

    Directory of Open Access Journals (Sweden)

    Aija Zilevica

    2005-04-01

    Full Text Available Antimicrobial resistance is one of the most urgent problems in medicine nowadays. The purpose of the study was to investigate the microorganisms resistant to first-line antimicrobials, including gram-positive cocci, particularly the methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococci, the major agents of nosocomial infections. Owing to the multi-resistance of these agents, precise diagnosis of the methicillin resistance of Staphylococci is of greatest clinical importance. It is not enough to use only conventional microbiological diagnostic methods. Biotechnological methods should be also involved. In our studies, the following methicillin resistance identification methods were used: the disk diffusion method, detection of the mecA gene by PCR, E-test and Slidex MRSA test. For molecular typing, PFGL, RAPD tests and detection of the coa gene were used. All the MRS strains were multiresistant to antibacterials. No vancomycine resistance was registered.

  6. Electrically resistive coating for remediation (regeneration) of a diesel particulate filter and method

    Science.gov (United States)

    Phelps, Amanda C [Malibu, CA; Kirby, Kevin K [Calabasas Hills, CA; Gregoire, Daniel J [Thousand Oaks, CA

    2012-02-14

    A resistively heated diesel particulate filter (DPF). The resistively heated DPF includes a DPF having an inlet surface and at least one resistive coating on the inlet surface. The at least one resistive coating is configured to substantially maintain its resistance in an operating range of the DPF. The at least one resistive coating has a first terminal and a second terminal for applying electrical power to resistively heat up the at least one resistive coating in order to increase the temperature of the DPF to a regeneration temperature. The at least one resistive coating includes metal and semiconductor constituents.

  7. The origin of polarized blackbody radiation from resistively heated multiwalled carbon nanotubes

    International Nuclear Information System (INIS)

    Aliev, Ali E.; Kuznetsov, Alexander A.

    2008-01-01

    We observed very pronounced polarization of light emitted by highly aligned free-standing multiwall carbon nanotube (MWNT) sheet in axial direction which is turned to the perpendicular polarization when a number of layers are increased. The radiation spectrum of resistively heated MWNT sheet closely follows to the Plank's blackbody radiation distribution. The obtained polarization features can be described by a classical dielectric cylindrical shell model, taking into consideration the contribution of delocalized π-electrons (π surface plasmons). In absorption (emission) the optical transverse polarizability, which is much smaller than longitudinal one, is substantially suppressed by depolarization effect due to screening by induced charges. This phenomenon suggests very simple and precise method to estimate the alignment of nanotubes in bundles or large assemblies

  8. Evaluating the effectiveness of heat-resistant cast steel filtration from the results of structure examinations

    Directory of Open Access Journals (Sweden)

    Asłanowicz M.

    2007-01-01

    Full Text Available Filtration guarantees castings characterised by high quality and free from any non-metallic inclusions, which are formed at the stage of melting and pouring of liquid metal. This article discusses the problem of the effectiveness of filtration process taking as an example heat-resistant cast steel poured into ceramic moulds. In investigations, foamed zircon filters made by FerroTerm Sp. z o.o. The effectiveness of filtration was described and examined using the results of metallographic examinations, including macro- and micro-structure examinations of metal and of cast metal/ceramic filter interface, and measurements of the content of non-metallic inclusions. The methods of investigations were presented, the obtained results were described, and relevant conclusions were drawn, all of them unmistakably indicating a very beneficial effect that filtration has on molten metal quality. Łódź, Poland, were used.

  9. Heat sensitive persons with multiple sclerosis are more tolerant to resistance exercise than to endurance exercise

    DEFF Research Database (Denmark)

    Skjerbæk, Anders G; Møller, Andreas Buch; Jensen, Ellen

    2012-01-01

    BACKGROUND: Heat sensitivity (HS) is reported by 58% of all persons with multiple sclerosis (MS), causing symptom exacerbation possibly limiting exercise participation. OBJECTIVE: The purpose of this study was to test the hypotheses that (a) a relationship between exercise-induced changes in core...... randomly completed a session of RE and EE, or EE and RE, respectively. Testing was conducted pre, post and one hour after exercise and consisted of Visual Analogue Scale (VAS) scoring (fatigue, spasticity, pain, strength, walking and balance), the 5-time sit-to-stand (5STS), the Multiple Sclerosis......-temperature (C(temp)) and changes in symptom intensity exists, and (b) that resistance exercise (RE), as a consequence of a minor increase in core temperature, will induce a lesser worsening of symptoms than endurance exercise (EE) in HS persons with MS. METHODS: On two separate days, 16 HS persons with MS...

  10. Comparison of resistive heating and forced-air warming to prevent inadvertent perioperative hypothermia.

    Science.gov (United States)

    John, M; Crook, D; Dasari, K; Eljelani, F; El-Haboby, A; Harper, C M

    2016-02-01

    Forced-air warming is a commonly used warming modality, which has been shown to reduce the incidence of inadvertent perioperative hypothermia (heating mattresses offer a potentially cheaper alternative, however, and one of the research recommendations from the National Institute for Health and Care Excellence was to evaluate such devices formally. We conducted a randomized single-blinded study comparing perioperative hypothermia in patients receiving resistive heating or forced-air warming. A total of 160 patients undergoing non-emergency surgery were recruited and randomly allocated to receive either forced-air warming (n=78) or resistive heating (n=82) in the perioperative period. Patient core temperatures were monitored after induction of anaesthesia until the end of surgery and in the recovery room. Our primary outcome measures included the final intraoperative temperature and incidence of hypothermia at the end of surgery. There was a significantly higher rate of hypothermia at the end of surgery in the resistive heating group compared with the forced-air warming group (P=0.017). Final intraoperative temperatures were also significantly lower in the resistive heating group (35.9 compared with 36.1°C, P=0.029). Hypothermia at the end of surgery in both warming groups was common (36% forced air warming, 54% resistive heating). Our results suggest that forced-air warming is more effective than resistive heating in preventing postoperative hypothermia. NCT01056991. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Natural Diversity in Heat Resistance of Bacteria and Bacterial Spores: Impact on Food Safety and Quality.

    Science.gov (United States)

    den Besten, Heidy M W; Wells-Bennik, Marjon H J; Zwietering, Marcel H

    2018-03-25

    Heat treatments are widely used in food processing often with the aim of reducing or eliminating spoilage microorganisms and pathogens in food products. The efficacy of applying heat to control microorganisms is challenged by the natural diversity of microorganisms with respect to their heat robustness. This review gives an overview of the variations in heat resistances of various species and strains, describes modeling approaches to quantify heat robustness, and addresses the relevance and impact of the natural diversity of microorganisms when assessing heat inactivation. This comparison of heat resistances of microorganisms facilitates the evaluation of which (groups of) organisms might be troublesome in a production process in which heat treatment is critical to reducing the microbial contaminants, and also allows fine-tuning of the process parameters. Various sources of microbiological variability are discussed and compared for a range of species, including spore-forming and non-spore-forming pathogens and spoilage organisms. This benchmarking of variability factors gives crucial information about the most important factors that should be included in risk assessments to realistically predict heat inactivation of bacteria and spores as part of the measures for controlling shelf life and safety of food products.

  12. Spatial fluxes and energy distributions of reactor fast neutrons in two types of heat resistant concretes

    International Nuclear Information System (INIS)

    Akki, T.S.; Benayad, S.A.; Megahid, R.M.

    1992-01-01

    Measurements have been carried out to study the spatial fluxes and energy distributions of reactor fast neutrons transmitted through two types of heat resistant concretes, serpentine concrete and magnetic lemonite concrete. The physical, chemical and mechanical properties of these concretes were checked by well known techniques. In addition, the effect of heating at temperatures up to 500deg C on the crystaline water content was checked by the method of differential thermal analysis. Measurements were performed using a collimated beam of reactor neutrons emitted from a 10 MW research reactor. The neutron spectra transmitted through concrete barriers of different thickness were measured by a scintillation spectrometer with NE-213 liquid organic scintillator. Discrimination against undesired pulses due to gamma-rays was achieved by a method based on pulse shape discrimination technique. The operating principle of this technique is based on the comparison of two weighted time integrals of the detector signal. The measured pulse amplitude distribution was converted to neutron energy distribution by a computational code based on double differentiation technique. The spectrometer workability and the accuracy of the unfolding technique were checked by measuring the neutron spectra of neutrons from Pu-α-Be and 252 Cf neutron sources. The obtained neutron spectra for the two concretes were used to derive the total cross sections for neutrons of different energies. (orig.)

  13. An Engineering Aerodynamic Heating Method for Hypersonic Flow

    Science.gov (United States)

    Riley, Christopher J.; DeJarnette, Fred R.

    1992-01-01

    A capability to calculate surface heating rates has been incorporated in an approximate three-dimensional inviscid technique. Surface streamlines are calculated from the inviscid solution, and the axisymmetric analog is then used along with a set of approximate convective-heating equations to compute the surface heat transfer. The method is applied to blunted axisymmetric and three-dimensional ellipsoidal cones at angle of attack for the laminar flow of a perfect gas. The method is also applicable to turbulent and equilibrium-air conditions. The present technique predicts surface heating rates that compare favorably with experimental (ground-test and flight) data and numerical solutions of the Navier-Stokes (NS) and viscous shock-layer (VSL) equations. The new technique represents a significant improvement over current engineering aerothermal methods with only a modest increase in computational effort.

  14. Determination of tungsten in high-alloy steels and heat resisting alloys by isotope dilution-spark source mass spectrometry

    International Nuclear Information System (INIS)

    Saito, Morimasa; Yamada, Kei; Okochi, Haruno; Hirose, Fumio

    1983-01-01

    Tungsten in high-alloy steels and heat-resisting alloys was determined by isotope dilution method combined with spark source mass spectrometry by using 183 W enriched tungsten. The spike solution was prepared by fusing tungsten trioxide in sodium carbonate. A high-alloy steel sample was dissolved in the mixture of sulfuric acid and phosphoric acid together with the spike solution; a sample of heat resisting alloy was similarly dissolved in the mixture of hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid. The solution was evaporated to give dense white fumes. Tungsten was separated from the residue by a conventional cinchonine salt-precipitation method. The salt was ignited, and the residue was mixed with graphite powder and pressed into electrodes. The isotope 183 W and 184 W were measured. The method was applied to the determination of tungsten in JSS and NBS standard high-alloy steels and JAERI standard nickel- and NBS standard cobalt-base heat resisting alloys containing more than 0.05% tungsten. The results were obtained with satisfactory precision and accuracy. However, the results obtained for JSS standard high- speed steels containing molybdenum tended to be significantly lower than the certified values. (author)

  15. resistivity methods in hydro-geophysical investigation

    African Journals Online (AJOL)

    Home

    age (Short and Stauble, 1967; Asseez, 1989). Above the .... The resistivity of the pore water was used for estimating the total dissolved solids (TDS) in ppm of groundwater using equation (4). .... clear felling a sitka spruce (pica stichensis).

  16. An inverse hyperbolic heat conduction problem in estimating surface heat flux by the conjugate gradient method

    International Nuclear Information System (INIS)

    Huang, C.-H.; Wu, H.-H.

    2006-01-01

    In the present study an inverse hyperbolic heat conduction problem is solved by the conjugate gradient method (CGM) in estimating the unknown boundary heat flux based on the boundary temperature measurements. Results obtained in this inverse problem will be justified based on the numerical experiments where three different heat flux distributions are to be determined. Results show that the inverse solutions can always be obtained with any arbitrary initial guesses of the boundary heat flux. Moreover, the drawbacks of the previous study for this similar inverse problem, such as (1) the inverse solution has phase error and (2) the inverse solution is sensitive to measurement error, can be avoided in the present algorithm. Finally, it is concluded that accurate boundary heat flux can be estimated in this study

  17. A new method for simultaneous measurement of convective and radiative heat flux in car underhood applications

    International Nuclear Information System (INIS)

    Khaled, M; Garnier, B; Peerhossaini, H; Harambat, F

    2010-01-01

    A new experimental technique is presented that allows simultaneous measurement of convective and radiative heat flux in the underhood. The goal is to devise an easily implemented and accurate experimental method for application in the vehicle underhood compartment. The new method is based on a technique for heat-flux measurement developed by the authors (Heat flow (flux) sensors for measurement of convection, conduction and radiation heat flow 27036-2, © Rhopoint Components Ltd, Hurst Green, Oxted, RH8 9AX, UK) that uses several thermocouples in the thickness of a thermal resistive layer (foil heat-flux sensor). The method proposed here uses a pair of these thermocouples with different radiative properties. Measurements validating this novel technique are carried out on a flat plate with a prescribed constant temperature in both natural- and forced-convection flow regimes. The test flat plate is instrumented by this new technique, and also with a different technique that is intrusive but very accurate, used as reference here (Bardon J P and Jarny Y 1994 Procédé et dispositif de mesure transitoire de température et flux surfacique Brevet n°94.011996, 22 February). Discrepancies between the measurements by the two techniques are less than 10% for both convective and radiative heat flux. Error identification and sensitivity analysis of the new method are also presented

  18. A Method for testing the integrated thermal resistance of thermoelectric modules

    Science.gov (United States)

    Gao, Junling; Du, Qungui; Chen, Min

    2013-11-01

    The integrated thermal resistance (ITR) of thermoelectric modules (TEMs) is an important parameter that represents the thermal-conduction of ceramic substrates, copper conducting strips, and welding material used in the TEM as well as the thermal contact resistances between different materials. In this study, an accurate and practical test method is proposed for the ITR of TEMs according to thermoelectric heat transfer theory and the equivalent characteristics of heat flux through the cold and hot sides of TEMs in an open-circuit situation. By using such measurements and comparisons, it is verified that the measured ITR value in our mode is accurate and reliable. In particular this method accurately predicts the actual operating conditions of TEMs, in which TEMs are under certain mechanical pressure. It effectively solves the problem of thermal resistance extraction from operating TEMs and is of great significance in their analysis and optimization.

  19. Freestanding, heat resistant microporous film for use in energy storage devices

    Science.gov (United States)

    Pekala, Richard W.; Cherukupalli, Srinivas; Waterhouse, Robert R.

    2018-02-20

    Preferred embodiments of a freestanding, heat resistant microporous polymer film (10) constructed for use in an energy storage device (70, 100) implements one or more of the following approaches to exhibit excellent high temperature mechanical and dimensional stability: incorporation into a porous polyolefin film of sufficiently high loading levels of inorganic or ceramic filler material (16) to maintain porosity (18) and achieve low thermal shrinkage; use of crosslinkable polyethylene to contribute to crosslinking the polymer matrix (14) in a highly inorganic material-filled polyolefin film; and heat treating or annealing of biaxially oriented, highly inorganic material-filled polyolefin film above the melting point temperature of the polymer matrix to reduce residual stress while maintaining high porosity. The freestanding, heat resistant microporous polymer film embodiments exhibit extremely low resistance, as evidenced by MacMullin numbers of less than 4.5.

  20. Effects of heat input on the pitting resistance of Inconel 625 welds by overlay welding

    Science.gov (United States)

    Kim, Jun Seok; Park, Young IL; Lee, Hae Woo

    2015-03-01

    The objective of this study was to establish the relationship between the dilution ratio of the weld zone and pitting resistance depending on the heat input to welding of the Inconel alloy. Each specimen was produced by electroslag welding using Inconel 625 as the filler metal. In the weld zone of each specimen, dendrite grains were observed near the fusion line and equiaxed grains were observed on the surface. It was also observed that a melted zone with a high Fe content was formed around the fusion line, which became wider as the welding heat input increased. In order to evaluate the pitting resistance, potentiodynamic polarization tests and CPT tests were conducted. The results of these tests confirmed that there is no difference between the pitting resistances of each specimen, as the structures of the surfaces were identical despite the effect of the differences in the welding heat input for each specimen and the minor dilution effect on the surface.

  1. In-situ heating test in the sedimentary soft rock. Part 3. Monitoring of the extent of high temperature zone by resistivity tomography

    International Nuclear Information System (INIS)

    Kubota, Kenji; Suzuki, Koichi; Ikenoya, Takafumi; Takakura, Nozomu; Tani, Kazuo

    2009-01-01

    One of the major issues in disposal of nuclear waste is that the long term behaviors of sedimentary soft rocks can be affected by various environmental factors such as temperature or hydraulic conditions. Therefore, it is necessary to develop a method for evaluating the long term stability of caverns in sedimentary soft rocks as subjected to changes of environment. We have conducted in-situ heating test to evaluate the influence of high temperature to the surrounding rock mass at a depth of 50m. Resistivity monitoring is thought to be effective to map the extent of high temperature zone. So resistivity tomography was conducted during the heating. The results demonstrated that the resistivity of the rock mass around the heater well was decreased and this area was gradually expanded from the heated area during the heating. Resistivity of rock is proportional to that of pore water which is known to decrease with increasing temperature. This suggests that high temperature zone is detected and spatial distribution of temperature can be mapped by resistivity tomography. So resistivity tomography is expected to be one of the promising methods to monitor the heated area by nuclear waste. (author)

  2. An immersed-boundary method for conjugate heat transfer analysis

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jeong Chul; Lee, Joon Sik [Seoul National University, Seoul (Korea, Republic of); Ahn, Joon [Kookmin University, Seoul (Korea, Republic of)

    2017-05-15

    An immersed-boundary method is proposed for the analysis of conjugate problems of convective heat transfer in conducting solids. In- side the solid body, momentum forcing is applied to set the velocity to zero. A thermal conductivity ratio and a heat capacity ratio, between the solid body and the fluid, are introduced so that the energy equation is reduced to the heat diffusion equation. At the solid fluid interface, an effective conductivity is introduced to satisfy the heat flux continuity. The effective thermal conductivity is obtained by considering the heat balance at the interface or by using a harmonic mean formulation. The method is first validated against the analytic solution to the heat transfer problem in a fully developed laminar channel flow with conducting solid walls. Then it is applied to a laminar channel flow with a heated, block-shaped obstacle to show its validity for geometry with sharp edges. Finally the validation for a curvilinear solid body is accomplished with a laminar flow through arrayed cylinders.

  3. Operation method for after-heat removal

    International Nuclear Information System (INIS)

    Tamano, Toyomi; Sakuragi, Masanori; Kogiso, Zen-ichi; Wake, Minoru.

    1987-01-01

    Purpose: To moderate thermal shocks applied to a feedwater pipe plate portion at the inlet of a steam generator thereby maintaining the integrity and safety of an LMFBR type plant. Method: Water with feed from the condenser to a steam generator. Steams generated in the steam generator are introduced to an air/water separator in a recycling system and a control device is actuated. Water separated by the air/water separator is recycled to the steam generator, while monitoring the temperature variation coefficient for the feedwater temperature at the inlet of the steam generator. If the temperature variation coefficient exceeds a predetermined setting value, the recycling flow rate is decreased in accordance with the deviation. This can greatly moderate the thermal shocks applied to the feedwater pipe plate portion at the inlet of the steam generator upon starting of the recycling system. (Takahashi, M.)

  4. Problems on the Theory of Heat Resistance of Alloys

    Science.gov (United States)

    1960-07-26

    panels and wiring diagrams of both the board panel and the relay unit. 1. Furnace heating circuit The furnace may be connected into a 120- or a 220-v a-c...on the same board, there are, in addition, all the signal lamps and emergency relays. A ’.iw of one of the panels of the control board is shown in...the d1fo-Pratton rate, the stress, and the temperature for the ease of deformation. by slip. 2cperlmentaly, for monocrystalline specimens, i.e., Tih

  5. Optimum schedules of difficult-to-form heat-resistant alloys forging

    International Nuclear Information System (INIS)

    Majzengel'ter, V.A.; Shuvalov, A.A.; Perevozov, A.S.

    2000-01-01

    The process of manufacturing half finished discs for hydroturbine engines from heat resistant difficulty deformed nickel, iron-nickel and cobalt alloys (EI435, EI868, VZh145-ID, EK79-ID, EK152-ID, EI826, EP648-VI) is described. The recommendations on the modes of forging the single-phase nonaging and double phase aging alloys are developed. The conclusion is made, that the first compressions of ingots shoved be accomplished by small press runs. The subsequent compressions should constituted not less than 8% during one run. The total compression of the ingot during one heating should be within the concrete alloy properties. With the purpose of obtaining uniform fine-grain structure the ingot heating during the last manufacturing cycle should be accomplished within the range of 1100-1130 deg C for the majority of heat resistant alloys [ru

  6. Modeling of Methods to Control Heat-Consumption Efficiency

    Science.gov (United States)

    Tsynaeva, E. A.; Tsynaeva, A. A.

    2016-11-01

    In this work, consideration has been given to thermophysical processes in automated heat consumption control systems (AHCCSs) of buildings, flow diagrams of these systems, and mathematical models describing the thermophysical processes during the systems' operation; an analysis of adequacy of the mathematical models has been presented. A comparison has been made of the operating efficiency of the systems and the methods to control the efficiency. It has been determined that the operating efficiency of an AHCCS depends on its diagram and the temperature chart of central quality control (CQC) and also on the temperature of a low-grade heat source for the system with a heat pump.

  7. SOME METHODS FOR SAVING HEAT ENERGY WHILE MANUFACTURING VERTICAL INSULATING GLASS UNITS

    Directory of Open Access Journals (Sweden)

    S. A. Shybeka

    2018-01-01

    Full Text Available The paper proposes and considers two constructive methods for saving heat energy while manufacturing vertical insulating glass units with various gas filling of inter-glass space. The first method presupposes manufacturing of insulating glass units having specific thickness which is calculated in accordance with specific features of convective heat exchange in the closed loop circuit. Value of the heat-exchange coefficient depends on gas properties which is filling a chamber capacity (coefficients of thermal conductivity, volumetric expansion, kinematic viscosity, thermometric conducivity, temperature difference on the boundary of interlayer and its thickness. It has been shown that while increasing thickness of gas layer convective heat exchange coefficient is initially decreasing up to specific value and then after insignificant increase it practically remains constant. In this connection optimum thicknesses of filled inter-layers for widely-spread gas in production (dry air, argon, krypton, xenon and for carbon dioxide have determined in the paper. Manufacturing of insulating glass units with large thickness of gas chamber practically does not lead to an increase in resistance to heat transfer but it will increase gas consumption rate. The second industrial economic method is interrelated with application of carbon dioxide СО2 as a filler of inter-glass space which has some advantages in comparison with other gases (small cost due to abundance, nontoxicity, transparency for visual light and absorption of heat rays. Calculations have shown that application of carbon dioxide will make it possible to increase resistance to heat transfer of one-chamber glass unit by 0.05 m²×K/W (with emissivity factor of internal glass – 0.837 or by 0.16 m²×K/W (with emission factor – 0.1 in comparison with the glass unit where a chamber is filled with dry air.

  8. Experimental determination of the heat transfer coefficient in shell-and-tube condensers using the Wilson plot method

    Directory of Open Access Journals (Sweden)

    Havlik Jan

    2017-01-01

    Full Text Available This article deals with the experimental determination of heat transfer coefficients. The calculation of heat transfer coefficients constitutes a crucial issue in design and sizing of heat exchangers. The Wilson plot method and its modifications based on measured experimental data utilization provide an appropriate tool for the analysis of convection heat transfer processes and the determination of convection coefficients in complex cases. A modification of the Wilson plot method for shell-and-tube condensers is proposed. The original Wilson plot method considers a constant value of thermal resistance on the condensation side. The heat transfer coefficient on the cooling side is determined based on the change in thermal resistance for different conditions (fluid velocity and temperature. The modification is based on the validation of the Nusselt theory for calculating the heat transfer coefficient on the condensation side. A change of thermal resistance on the condensation side is expected and the value is part of the calculation. It is possible to improve the determination accuracy of the criterion equation for calculation of the heat transfer coefficient using the proposed modification. The criterion equation proposed by this modification for the tested shell-and-tube condenser achieves good agreement with the experimental results and also with commonly used theoretical methods.

  9. Heat treatment of NiCrFe alloy 600 to optimize resistance to intergranular stress corrosion

    Science.gov (United States)

    Steeves, A.F.; Bibb, A.E.

    A process of producing a NiCrFe alloy having a high resistance to stress corrosion cracking comprises heating a NiCrFe alloy to a temperature sufficient to enable the carbon present in the alloy body in the form of carbide deposits to enter into solution, rapidly cooling the alloy body, and heating the cooled body to a temperature between 1100 to 1500/sup 0/F for about 1 to 30 hours.

  10. Effect of heat treatment on the grooving corrosion resistance of ERW pipes

    International Nuclear Information System (INIS)

    Lee, Jong Kwon; Lee, Jae Young; Lim, Soo Hyun; Park, Ji Hwan; Seo, Bo Min; Kim, Seon Hwa

    2002-01-01

    The v-sharp grooving corrosion of ERW(electrical resistance welding) steel pipes limited their wide application in the industry in spite of their high productivity and efficiency. The grooving corrosion is caused mainly by the different microstructures between the matrix and weld that is formed during the rapid heating and cooling cycle in welding. By this localized corrosion reaction of pipes, it evolves economic problems such as the early damage of industrial facilities and pipe lines of apartment, and water pollution. Even though the diminishing of sulfur content is most effective to decrease the susceptibility of grooving corrosion, it requires costly process. In this study, improvement of grooving corrosion resistance was pursuited by post weld heat treatment in the temperature range between 650 .deg. C and 950 .deg. C. Also, the effect of heat input in the welding was investigated. By employing chromnoamperometry and potentiodynamic experiment, the corrosion rate and grooving corrosion index(α) were obtained. It was found that heat treatment could improve the grooving corrosion resistance. Among them, the heat treated at 900 .deg. C and 950 .deg. C had excellent grooving corrosion resistance. The index of heat treated specimen at 900 .deg. C and 950 .deg. C were 1.0, 1.2, respectively, which are almost immune to the grooving corrosion. Potential difference after the heat treatment, between base and weld metal was decreased considerably. While the as-received one measured 61∼71 mV, that of the 900 .deg. C heat treated steel pipe measured only 10mV. The results were explained and discussed

  11. Processing of light and heat-resistant alloys. Obrabotka legkikh i zharoprochnykh splavov

    Energy Technology Data Exchange (ETDEWEB)

    Belova, A F

    1976-01-01

    Results are given on the latest studies undertaken by Academician A.F. Belov. An examination is made of general problems in the processing (pressure, welding, thermal treatment, and others) of light and heat-resistant metals, problems in the technology and metal science studies of aluminum alloys, and problems of metallurgy and the processing of titanium and heat-resistant alloys. The publication is designed for researchers, designers, metallurgists, metal science specialists, machine building specialists, and students at corresponding institutions of higher learning.

  12. Influence of Heat Treatment on Abrasive Wear Resistance of Silumin Matrix Composite Castings

    Directory of Open Access Journals (Sweden)

    Gawdzińska K.

    2016-03-01

    Full Text Available The authors attempted at examining the effect of heat treatment on abrasive wear resistance of metal composite castings. Metal matrix composites were made by infiltrating preforms created from unordered short fibers (graphite or silumin with liquid aluminium alloy AlSi12(b. Thus prepared composites were subject to solution heat treatment at a temperature of 520°C for four hours, then aging at a temperature of 220°C for four hours. Abrasion resistance of the material was tested before and after thermal treatment.

  13. Effect of heat input on the microstructure, residual stresses and corrosion resistance of 304L austenitic stainless steel weldments

    Energy Technology Data Exchange (ETDEWEB)

    Unnikrishnan, Rahul, E-mail: rahulunnikrishnannair@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India); Idury, K.S.N. Satish, E-mail: satishidury@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India); Ismail, T.P., E-mail: tpisma@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India); Bhadauria, Alok, E-mail: alokbhadauria1@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India); Shekhawat, S.K., E-mail: satishshekhawat@gmail.com [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay (IITB), Powai, Mumbai 400076, Maharashtra (India); Khatirkar, Rajesh K., E-mail: rajesh.khatirkar@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India); Sapate, Sanjay G., E-mail: sgsapate@yahoo.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India)

    2014-07-01

    Austenitic stainless steels are widely used in high performance pressure vessels, nuclear, chemical, process and medical industry due to their very good corrosion resistance and superior mechanical properties. However, austenitic stainless steels are prone to sensitization when subjected to higher temperatures (673 K to 1173 K) during the manufacturing process (e.g. welding) and/or certain applications (e.g. pressure vessels). During sensitization, chromium in the matrix precipitates out as carbides and intermetallic compounds (sigma, chi and Laves phases) decreasing the corrosion resistance and mechanical properties. In the present investigation, 304L austenitic stainless steel was subjected to different heat inputs by shielded metal arc welding process using a standard 308L electrode. The microstructural developments were characterized by using optical microscopy and electron backscattered diffraction, while the residual stresses were measured by X-ray diffraction using the sin{sup 2}ψ method. It was observed that even at the highest heat input, shielded metal arc welding process does not result in significant precipitation of carbides or intermetallic phases. The ferrite content and grain size increased with increase in heat input. The grain size variation in the fusion zone/heat affected zone was not effectively captured by optical microscopy. This study shows that electron backscattered diffraction is necessary to bring out changes in the grain size quantitatively in the fusion zone/heat affected zone as it can consider twin boundaries as a part of grain in the calculation of grain size. The residual stresses were compressive in nature for the lowest heat input, while they were tensile at the highest heat input near the weld bead. The significant feature of the welded region and the base metal was the presence of a very strong texture. The texture in the heat affected zone was almost random. - Highlights: • Effect of heat input on microstructure, residual

  14. Manufacture of a heat-resistant alloy with modified specifications for HTGR structural applications

    International Nuclear Information System (INIS)

    Sahira, K.; Kondo, T.; Takeiri, T.

    1984-01-01

    A method of manufacturing a nuclear grade nickel-base heat-resistant alloy in application to heliumcooled reactor primary circuit components has been developed. The Hastelloy-XR alloy, a version of Hastelloy-X, was made available by combining the basic studies of the oxidation behavior of Hastelloy-X and the improvement of manufacturing techniques. In the primary and remelting steps, the choice of appropriate processes was made by performing numerical analyses of the statistical deviation of both chemical composition and the products' mechanical properties. The feasibility of making larger electroslag remelting ingots with reasonable control of macrosegregation was examined by the calculation of a molten metal pool shape during melting. The hot workability of Hastelloy-XR was confirmed to be equivalent to that of Hastelloy-X and the importance of controlling the thermal and mechanical processes more closely was stressed in obtaining a higher level of quality assurance for the nuclear applications. The possibility of enhancing the high-temperature mechanical performance of Hastelloy-XR was suggested based on the preliminary test results with the heats manufactured with controlled boron content

  15. Variation in Resistance of Natural Isolates of Escherichia coli O157 to High Hydrostatic Pressure, Mild Heat, and Other Stresses

    OpenAIRE

    Benito, Amparo; Ventoura, Georgia; Casadei, Maria; Robinson, Tobin; Mackey, Bernard

    1999-01-01

    Strains of Escherichia coli O157 isolated from patients with clinical cases of food-borne illness and other sources exhibited wide differences in resistance to high hydrostatic pressure. The most pressure-resistant strains were also more resistant to mild heat than other strains. Strain C9490, a representative pressure-resistant strain, was also more resistant to acid, oxidative, and osmotic stresses than the pressure-sensitive strain NCTC 12079. Most of these differences in resistance were o...

  16. Effect of pH on Thermoanaerobacterium thermosaccharolyticum DSM 571 growth, spore heat resistance and recovery.

    Science.gov (United States)

    Mtimet, Narjes; Guégan, Stéphanie; Durand, Lucile; Mathot, Anne-Gabrielle; Venaille, Laurent; Leguérinel, Ivan; Coroller, Louis; Couvert, Olivier

    2016-05-01

    Thermophilic spore-forming bacteria are potential contaminants in several industrial sectors involving high temperatures (40-65 °C) in the manufacturing process. Among those thermophilic spore-forming bacteria, Thermoanaerobacterium thermosaccharolyticum, called "the swelling canned food spoiler", has generated interest over the last decade in the food sector. The aim of this study was to investigate and to model pH effect on growth, heat resistance and recovery abilities after a heat-treatment of T. thermosaccharolyticum DSM 571. Growth and sporulation were conducted on reinforced clostridium media and liver broth respectively. The highest spore heat resistances and the greatest recovery ability after a heat-treatment were obtained at pH condition allowing maximal growth rate. Growth and sporulation boundaries were estimated, then models using growth limits as main parameters were extended to describe and quantify the effect of pH on recovery of injured spores after a heat-treatment. So, cardinal values were used as a single set of parameters to describe growth, sporulation and recovery abilities. Besides, this work suggests that T. thermosaccharolyticum preserve its ability for germination and outgrowth after a heat-treatment at a low pH where other high resistant spore-forming bacteria like Geobacillus stearothermophilus are unable to grow. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Heat-transfer resistance at solid-liquid interfaces: a tool for the detection of single-nucleotide polymorphisms in DNA.

    Science.gov (United States)

    van Grinsven, Bart; Vanden Bon, Natalie; Strauven, Hannelore; Grieten, Lars; Murib, Mohammed; Monroy, Kathia L Jiménez; Janssens, Stoffel D; Haenen, Ken; Schöning, Michael J; Vermeeren, Veronique; Ameloot, Marcel; Michiels, Luc; Thoelen, Ronald; De Ceuninck, Ward; Wagner, Patrick

    2012-03-27

    In this article, we report on the heat-transfer resistance at interfaces as a novel, denaturation-based method to detect single-nucleotide polymorphisms in DNA. We observed that a molecular brush of double-stranded DNA grafted onto synthetic diamond surfaces does not notably affect the heat-transfer resistance at the solid-to-liquid interface. In contrast to this, molecular brushes of single-stranded DNA cause, surprisingly, a substantially higher heat-transfer resistance and behave like a thermally insulating layer. This effect can be utilized to identify ds-DNA melting temperatures via the switching from low- to high heat-transfer resistance. The melting temperatures identified with this method for different DNA duplexes (29 base pairs without and with built-in mutations) correlate nicely with data calculated by modeling. The method is fast, label-free (without the need for fluorescent or radioactive markers), allows for repetitive measurements, and can also be extended toward array formats. Reference measurements by confocal fluorescence microscopy and impedance spectroscopy confirm that the switching of heat-transfer resistance upon denaturation is indeed related to the thermal on-chip denaturation of DNA. © 2012 American Chemical Society

  18. A thermal plasmonic sensor platform: resistive heating of nanohole arrays.

    Science.gov (United States)

    Virk, Mudassar; Xiong, Kunli; Svedendahl, Mikael; Käll, Mikael; Dahlin, Andreas B

    2014-06-11

    We have created a simple and efficient thermal plasmonic sensor platform by letting a DC current heat plasmonic nanohole arrays. The sensor can be used to determine thermodynamic parameters in addition to monitoring molecular reactions in real-time. As an application example, we use the thermal sensor to determine the kinetics and activation energy for desorption of thiol monolayers on gold. Further, the temperature of the metal can be measured optically by the spectral shift of the bonding surface plasmon mode (0.015 nm/K). We show that this resonance shift is caused by thermal lattice expansion, which reduces the plasma frequency of the metal. The sensor is also used to determine the thin film thermal expansion coefficient through a theoretical model for the expected resonance shift.

  19. Does enhanced heat resistance of irradiated insects represent greater ability to adapt

    International Nuclear Information System (INIS)

    Ducoff, H.S.; MacDuff, R.A.

    1985-01-01

    Previous work from this lab demonstrated that irradiated flour beetles (Tribolium) develop resistance to oxygen with similar kinetics: greater sensitivity for about 1 week, increasing resistance over the next week, and resistance persisting for 3-6 months. This is in contrast to the rapid development of heat resistance in yeast exposed to UV or ionizing radiation and to rapid induction of heat-stress proteins in E. coli exposed to UV or nalidixic acid. The authors' early work did not distinguish between intrinsic heat resistance and enhanced ability to adapt. They tried to resolve this problem by comparing response of irradiated and of control beetles to challenge at 45 0 C with or without brief exposure to 41 0 C just prior to challenge. Mean lethal exposure time at 45 0 C was increased to about the same extent in both populations after 15 min at 41 0 C, suggesting that irradiation increases insectors' intrinsic resistance to stress rather than their ability to adapt

  20. The heat-shock protein/chaperone network and multiple stress resistance.

    Science.gov (United States)

    Jacob, Pierre; Hirt, Heribert; Bendahmane, Abdelhafid

    2017-04-01

    Crop yield has been greatly enhanced during the last century. However, most elite cultivars are adapted to temperate climates and are not well suited to more stressful conditions. In the context of climate change, stress resistance is a major concern. To overcome these difficulties, scientists may help breeders by providing genetic markers associated with stress resistance. However, multistress resistance cannot be obtained from the simple addition of single stress resistance traits. In the field, stresses are unpredictable and several may occur at once. Consequently, the use of single stress resistance traits is often inadequate. Although it has been historically linked with the heat stress response, the heat-shock protein (HSP)/chaperone network is a major component of multiple stress responses. Among the HSP/chaperone 'client proteins', many are primary metabolism enzymes and signal transduction components with essential roles for the proper functioning of a cell. HSPs/chaperones are controlled by the action of diverse heat-shock factors, which are recruited under stress conditions. In this review, we give an overview of the regulation of the HSP/chaperone network with a focus on Arabidopsis thaliana. We illustrate the role of HSPs/chaperones in regulating diverse signalling pathways and discuss several basic principles that should be considered for engineering multiple stress resistance in crops through the HSP/chaperone network. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  1. Compatibility of heat resistant alloys with boron carbide, (4)

    International Nuclear Information System (INIS)

    Baba, Sinichi; Saruta, Toru; Ooka, Kiichi; Tanaka, Isao; Aoyama, Isao

    1985-07-01

    This paper relates to the compatibility test of control rod sheath (Hastelloy XR alloy) and neutron absorber (boronated graphite) for the VHTR, which has been researched and developed by JAERI. The irradiation was conducted by using the OGL-1 irradiation facility in the JMTR in order to study reaction behaviour between Hastelloy XR alloy and boronated graphite as well as to determine a reaction barrier performance of refractory metal foils Nb, Mo, W and Re. Irradiation conditions were as follows. Neutron dose : 4.05 x 10 22 m -2 (E 18 m -2 (E > 0.16 pJ, 1 Mev). Helium coolant : Average temperature 855 0 C, Pressure 2.94 MPa, Total impurity concentration 400 kBq/m 3 . Irradiation time : 5.0 Ms (1390 hours). Post-irradiation examinations i.e. visual inspection, dimensional inspection, weight measurement, metallography, hardness test, morphological observations by SEM and analysis of element distributions by EPMA were carried out. In the result, reaction products of Hastelloy XR alloy were observed in the ellipsoidal form locally. These results were same as those of the out-of-pile tests. Obvious irradiation effects were not detectable but a little accelarated increase in reaction depth of Hastelloy XR alloy by heat effect of specimens was observed. The refractory metal foils had a good performance of reaction barrier between Hastelloy XR alloy and boronated graphite. Furthermore, movement of Ni, Fe and Cr in the reaction area of Hastelloy XR alloy, difference in the reaction depth of B and C, irradiation effects on diffusion coefficient, lithium production and heat effect are discussed. (author)

  2. Measuring method for heat-shrinkage of fuel pellet

    International Nuclear Information System (INIS)

    Komono, Akira; Ishizaki, Jin; Inaki, Kiyohiro.

    1997-01-01

    The present invention concerns a method of determining an amount of heat-shrinkage of UR 2 pellets containing gadolinium oxide (Gd 2 O 2 ) based on the difference of the density thereof before and after heating. In a heat shrinkage test of UO 2 pellets containing from 1.0 to 15.0% by weight of gadolinium oxide, the amount of heat-shrinkage is measured under the condition of heat-retaining temperature: from 1700 to 1750degC, temperature elevation time and lowering time: from 90 to 120mins, heat-retaining time: 24hours, inert gas atmosphere, gas pressure: 0.35kg/cm 2 and gas dew point: from -55 to 40degC without changing O/M. This invention has a feature in the use of the inert gas and the elevation of the dew point of the gas. Then, oxygen dissociation phenomenon from crystal lattices of the fuel pellets is suppressed, and normal densification value is shown. Then, fuel pellets of good quality with less fluctuation of the heat-shrinkage can be obtained. (N.H.)

  3. A new method for distribution of consumed heat in a fuel and costs in power and heating plants

    Energy Technology Data Exchange (ETDEWEB)

    Kadrnozka, J [Technical Univ., Brno (Czech Republic)

    1993-09-01

    There is described a new method for distribution of consumed heat in a fuel and costs in the power and heating plants, which is based on the relatively the same proportion of advantages followed from combine generation of electricity and heat on electricity and heat. The method is physically substantiated, it is very universal and it is applied for new types of power and heating plants and for distribution of investment costs and other costs. (orig./GL)

  4. Optimization of a waste heat recovery system with thermoelectric generators by three-dimensional thermal resistance analysis

    International Nuclear Information System (INIS)

    Huang, Gia-Yeh; Hsu, Cheng-Ting; Fang, Chun-Jen; Yao, Da-Jeng

    2016-01-01

    Highlights: • The waste heat recovery system is modeled by three-dimensional thermal resistance. • This is a time-saving and efficient method to estimate power generation from TEGs. • Relations between power generation and varied factors can be rapidly revealed. • TEGs positions and uniformity of velocity profile should be considered together. • Power generation is more sensitive to either internal or external flow velocity. - Abstract: Three-dimensional (3D) thermal resistance analysis provides a rapid and simple method to estimate the power generated from a waste heat recovery system with thermoelectric generators (TEGs), and facilitates an optimization of the system. Such a system comprises three parts – a waste heat recovery chamber, TEG modules and a cooling system. A fin-structured duct serves as a waste heat recovery chamber, which is attached to the hot sides of the TEGs; the cold sides of the TEGs are attached to a cooling system. The waste heat recovery chamber harvests energy from exhaust heat that the TEGs convert into electricity. The estimation of generated power is an important part of the system design. Methods of Computational Fluid Dynamics (CFD) assist the analysis and improve the performance with great accuracy but great computational duration. The use of this method saves much time relative to such CFD methods. In 3D thermal resistance analysis, a node of unknown temperature is located at the centroid of each cell into which the system is divided. The relations of unknown temperatures at the cells are based on the energy conservation and the definition of thermal resistance. The temperatures of inlet waste hot gas and ambient fluid are known. With these boundary conditions, the unknown temperatures in the system are solved, enabling estimation of the power generated with TEGs. A 3D model of the system was simulated with FloTHERM; its numerical solution matched the solution of the 3D thermal resistance analysis within 6%. The power

  5. Reduction of Ag–Si electrical contact resistance by selective RF heating

    International Nuclear Information System (INIS)

    De Wijs, W-J A; Ljevar, S; Van de Sande, M J; De With, G

    2016-01-01

    Fast and selective inductive heating of pre-sintered silver lines on silicon as present in solar cells using 27 MHz radio-frequency inductive fields is shown. IR measurements of silicon substrates show that above 450 °C the heating rate of the samples increases sharply, indicating that both the silver and the silicon are heated. By moving the substrate with respect to the RF antenna and modulation of the RF field, silicon wafers were heated reproducibly above 450 °C with heating rates in excess of 200 °C s −1 . Furthermore, selective heating of lines of pre-sintered silver paste was shown below the 450 °C threshold on silicon substrates. The orientation of the silver tracks relative to the RF antenna appeared to be crucial for homogeneity of heating. Transmission line measurements show a clear effect on contact formation between the silver lines and the silicon substrate. To lower the contact resistance sufficiently for industrial feasibility, a high temperature difference between the Si substrate and the Ag tracks is required. The present RF heating process does not match the time scale needed for contact formation between silver and silicon sufficiently, but the significantly improved process control achieved shows promise for applications requiring fast heating and cooling rates. (paper)

  6. Analytical methods for heat transfer and fluid flow problems

    CERN Document Server

    Weigand, Bernhard

    2015-01-01

    This book describes useful analytical methods by applying them to real-world problems rather than solving the usual over-simplified classroom problems. The book demonstrates the applicability of analytical methods even for complex problems and guides the reader to a more intuitive understanding of approaches and solutions. Although the solution of Partial Differential Equations by numerical methods is the standard practice in industries, analytical methods are still important for the critical assessment of results derived from advanced computer simulations and the improvement of the underlying numerical techniques. Literature devoted to analytical methods, however, often focuses on theoretical and mathematical aspects and is therefore useless to most engineers. Analytical Methods for Heat Transfer and Fluid Flow Problems addresses engineers and engineering students. The second edition has been updated, the chapters on non-linear problems and on axial heat conduction problems were extended. And worked out exam...

  7. Heat resistance of Escherichia coli O157:H7 in apple juice.

    Science.gov (United States)

    Splittstoesser, D F; McLellan, M R; Churey, J J

    1996-03-01

    The objective was to determine the effect of cider composition on the heat resistance of Escherichia coli O157:H7. The average D52 value in a model Empire apple juice was 18 min with a z value of 4.8 degrees C. Increasing the Brix from 11.8 to 16.5 degrees had no effect on thermal resistance, while increasing L-malic acid from 0.2 to 0.8%, or reducing the pH from 4.4 to 3.6 sensitized the cells to heat. The greatest effect on heat resistance was afforded by the preservatives benzoic and sorbic acids: D50 values in ciders containing 1,000 mg/l were 5.2 min in the presence of sorbic acid and only 0.64 min in the presence of benzoic acid. Commercial apple juice concentrates yielded lower numbers of survivors than single-strength juices even though their higher sugar concentrations of about 46 degrees Brix increased heat resistance.

  8. Understanding decay resistance, dimensional stability and strength changes in heat treated and acetylated wood

    Science.gov (United States)

    Roger M. Rowell; Rebecca E. Ibach; James McSweeny; Thomas Nilsson

    2009-01-01

    Reductions in hygroscopicity, increased dimensional stability and decay resistance of heat-treated wood depend on decomposition of a large portion of the hemicelluloses in the wood cell wall. In theory, these hemicelluloses are converted to small organic molecules, water and volatile furan-type intermediates that can polymerize in the cell wall. Reductions in...

  9. Stripping demolition of reinforced concrete by electric heating method

    International Nuclear Information System (INIS)

    Nakagawa, Wahei; Nishita, Kiwamu; Kasai, Yoshio

    1993-01-01

    The present paper describes the procedures and results of a series of experiments the authors conducted to verify the efficiency of the electric heating method, previously proposed for so-called stripping demolition by applying electric current through reinforcing bars. In this method, a low voltage high current is run from one end to the other of a reinforcing bar or bars existing in a concrete structure, inducing intense heat in the bar(s) which in its turn brings about cracks in the surrounding concrete mass, facilitating secondary demolition by hammer picks or other means. The experiments were performed on full-scale biological shield wall mock-ups of a BWR and a small reactor. The results of the experiments are summarized as follows. (1) When electric current is applied through reinforcing bars, the bond between concrete and bars is loosened, and cracks start from one bar and progress toward other bars. Under appropriate conditions, the cracks in concrete run from the contact surface at one bar all the way to its the contact surface on another bar. (2) Cracks appear and grow only between two electrodes between which current is applied, not extending out of the area thus defined. (3) The concrete in the region closer to a current-bearing bar is intensely heated, whereas the concrete far from the bars remains nearly unheated. (4) Concrete walls after electric heating of bars disintegrates, if demolished with hammers, with the covering concrete are removed from the remaining portion of the structure together with heated bars, in shapes of flakes. (5) The reinforced concrete collapses in massive pieces of concrete, without generating much dust as is the case with the demolition of a concrete structure not heated by electricity. Results of the experiments show that the electric heating method is worth applying also to the demolition of nuclear power plants where concrete in the radioactivated surface region of shield walls needs to be stripped off in flakes

  10. Radiative heat transfer by the Monte Carlo method

    CERN Document Server

    Hartnett †, James P; Cho, Young I; Greene, George A; Taniguchi, Hiroshi; Yang, Wen-Jei; Kudo, Kazuhiko

    1995-01-01

    This book presents the basic principles and applications of radiative heat transfer used in energy, space, and geo-environmental engineering, and can serve as a reference book for engineers and scientists in researchand development. A PC disk containing software for numerical analyses by the Monte Carlo method is included to provide hands-on practice in analyzing actual radiative heat transfer problems.Advances in Heat Transfer is designed to fill the information gap between regularly scheduled journals and university level textbooks by providing in-depth review articles over a broader scope than journals or texts usually allow.Key Features* Offers solution methods for integro-differential formulation to help avoid difficulties* Includes a computer disk for numerical analyses by PC* Discusses energy absorption by gas and scattering effects by particles* Treats non-gray radiative gases* Provides example problems for direct applications in energy, space, and geo-environmental engineering

  11. Method for pre-heating lmfbr type reactors

    International Nuclear Information System (INIS)

    Yokozawa, Atsushi; Kataoka, Hajime.

    1978-01-01

    Purpose: To enable pre-heating for the inside of the reactor container and the inside of the coolant recycling system with no additional facilities. Method: The coolant recycling system is composed of a heat exchanger, a mechanical pump, a check valve, a flow meter or the like and it is connected in series by way of a pipe line to a reactor container. The mechanical pump is used as a gas recycling device upon pre-heating and it is designed so that a blower such as a fan can be replaced for the impeller of the pump. The inside of the reactor container and the inside of the coolant recycling system is at first filled with an inert gas such as for use with cover gas. Then, nuclear fuels are loaded to attain criticality. Simultaneously, the blower is started and the control rods are operated while cooling the nuclear fuel with the inert gas thus to obtain heat required for pre-heating the pipe line or the like from the nuclear fuels. After the completion of the pre-heating, the liquid metal is charged. (Ikeda, J.)

  12. Evaluation method for radiative heat transfer in polydisperse water droplets

    International Nuclear Information System (INIS)

    Maruyama, Shigenao; Nakai, Hirotaka; Sakurai, Atsushi; Komiya, Atsuki

    2008-01-01

    Simplifications of the model for nongray radiative heat transfer analysis in participating media comprised of polydisperse water droplets are presented. Databases of the radiative properties for a water droplet over a wide range of wavelengths and diameters are constructed using rigorous Mie theory. The accuracy of the radiative properties obtained from the database interpolation is validated by comparing them with those obtained from the Mie calculations. The radiative properties of polydisperse water droplets are compared with those of monodisperse water droplets with equivalent mean diameters. Nongray radiative heat transfer in the anisotropic scattering fog layer, including direct and diffuse solar irradiations and infrared sky flux, is analyzed using REM 2 . The radiative heat fluxes within the fog layer containing polydisperse water droplets are compared with those in the layer containing monodisperse water droplets. Through numerical simulation of the radiative heat transfer, polydisperse water droplets can be approximated by using the Sauter diameter, a technique that can be useful in several research fields, such as engineering and atmospheric science. Although this approximation is valid in the case of pure radiative transfer problems, the Sauter diameter is reconfirmed to be the appropriate diameter for approximating problems in radiative heat transfer, although volume-length mean diameter shows better accordance in some cases. The CPU time for nongray radiative heat transfer analysis with a fog model is evaluated. It is proved that the CPU time is decreased by using the databases and the approximation method for polydisperse particulate media

  13. An efficient and low resistant circumferential overlap trisection helical baffle heat exchanger with folded baffles

    International Nuclear Information System (INIS)

    Dong, Cong; Li, Dongshuang; Zheng, Youqu; Li, Guoneng; Suo, Yange; Chen, Yaping

    2016-01-01

    Highlights: • The novel cothHXf with circumferential overlap and folded baffles is first proposed. • The key sections of cylindrical and dumbbell are constructed to analyze local flow field characteristics. • The restricted leakage, easier to install and low resistant characteristics are emphasized. • The enhanced heat transfer mechanism of Dean Vortex secondary flow is analyzed. • A variety of comprehensive efficiency assessments are used. - Abstract: An efficient and low resistant circumferential overlap trisection helical baffle shell-and-tube heat exchanger with folded baffles (cothHXf) is presented. It is a modified trisection helical baffle heat exchanger with folded helical baffles for setting rods-and-spanning sleeves. It not only inherits all the merits of circumferential overlap helical baffle scheme, but also adds many additional advantages, such as supporting the inclined baffles with the least rods, simplifying the manufacturing process of spanning tubes and effectively inhibiting the reverse leakage at triangular areas between adjacent baffles. The improved flow characteristic and heat transfer enhancement mechanism of this heat exchanger were numerically investigated in comparison with conventional segmental baffles shell-and-tube heat exchanger (segHX). The flow fields within triangular area of adjacent baffles and nearby regions were depicted. The impacts of the folded baffles on shell-side helical flow, secondary vortex flow, and leakage pattern were analyzed. The distribution configurations of fields of velocity, pressure, temperature and local heat flow rate were revealed. The results show that the heat transfer performance and comprehensive performance evaluation indexes of the cothHXf are much better than those of the segHX while the pressure drop of the cothHXf is much lower than that of the segHX. The numerical simulation results of vivid distributions of flow and thermal fields of the cothHXf can provide theoretical basis for an

  14. Modeling heat resistance of Bacillus weihenstephanensis and Bacillus licheniformis spores as function of sporulation temperature and pH.

    Science.gov (United States)

    Baril, Eugénie; Coroller, Louis; Couvert, Olivier; Leguérinel, Ivan; Postollec, Florence; Boulais, Christophe; Carlin, Frédéric; Mafart, Pierre

    2012-05-01

    Although sporulation environmental factors are known to impact on Bacillus spore heat resistance, they are not integrated into predictive models used to calculate the efficiency of heating processes. This work reports the influence of temperature and pH encountered during sporulation on heat resistance of Bacillus weihenstephanensis KBAB4 and Bacillus licheniformis AD978 spores. A decrease in heat resistance (δ) was observed for spores produced either at low temperature, at high temperature or at acidic pH. Sporulation temperature and pH maximizing the spore heat resistance were identified. Heat sensitivity (z) was not modified whatever the sporulation environmental factors were. A resistance secondary model inspired by the Rosso model was proposed. Sporulation temperatures and pHs minimizing or maximizing the spore heat resistance (T(min(R)), T(opt(R)), T(max(R)), pH(min(R)) and pH(opt(R))) were estimated. The goodness of the model fit was assessed for both studied strains and literature data. The estimation of the sporulation temperature and pH maximizing the spore heat resistance is of great interest to produce spores assessing the spore inactivation in the heating processes applied by the food industry. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. The Transcriptional Heat Shock Response of Salmonella Typhimurium Shows Hysteresis and Heated Cells Show Increased Resistance to Heat and Acid Stress

    DEFF Research Database (Denmark)

    Pin, C.; Hansen, Trine; Munoz-Cuevas, M.

    2012-01-01

    We investigated if the transcriptional response of Salmonella Typhimurium to temperature and acid variations was hysteretic, i.e. whether the transcriptional regulation caused by environmental stimuli showed memory and remained after the stimuli ceased. The transcriptional activity of non......, implying that down-regulation was significantly less synchronized than upregulation. The hysteretic transcriptional response to heat shock was accompanied by higher resistance to inactivation at 50uC as well as cross-resistance to inactivation at pH 3; however, growth rates and lag times at 43uC and at p......H 4.5 were not affected. The exposure to pH 5 only caused up-regulation of 12 genes and this response was neither hysteretic nor accompanied of increased resistance to inactivation conditions. Cellular memory at the transcriptional level may represent a mechanism of adaptation to the environment...

  16. Integrated conjugate heat transfer analysis method for in-vessel retention with external reactor vessel cooling - 15477

    International Nuclear Information System (INIS)

    Park, J.W.; Bae, J.H.; Seol, W.C.

    2015-01-01

    An integrated conjugate heat transfer analysis method for the thermal integrity of a reactor vessel under external reactor vessel cooling conditions is developed to resolve light metal layer focusing effect issue. The method calculates steady-state 3-dimensional temperature distribution of a reactor vessel using coupled conjugate heat transfer between in-vessel 3-layered stratified corium (metallic pool, oxide pool and heavy metal) and polar-angle dependent boiling heat transfer at the outer surface of a reactor vessel. The 3-layer corium heat transfer model is utilizing lumped-parameter thermal-resistance circuit method and ex-vessel boiling regimes are parametrically considered. The thermal integrity of a reactor vessel is addressed in terms of un-molten thickness profile. The vessel 3-dimensional heat conduction is validated against a commercial code. It is found that even though the internal heat flux from the metal layer goes far beyond critical heat flux (CHF) the heat flux from the outermost nodes of the vessel may be maintained below CHF due to massive vessel heat diffusion. The heat diffusion throughout the vessel is more pronounced for relatively low heat generation rate in an oxide pool. Parametric calculations are performed considering thermal conditions such as peak heat flux from a light metal layer, heat generation in an oxide pool and external boiling conditions. The major finding is that the most crucial factor for success of in-vessel retention is not the mass of the molten light metal above the oxide pool but the heat generation rate inside the oxide pool and the 3-dimensional vessel heat transfer provides a much larger minimum vessel wall thickness. (authors)

  17. Prediction of heat capacities and heats of vaporization of organic liquids by group contribution methods

    DEFF Research Database (Denmark)

    Ceriani, Roberta; Gani, Rafiqul; Meirelles, A.J.A.

    2009-01-01

    In the present work a group contribution method is proposed for the estimation of the heat capacity of organic liquids as a function of temperature for fatty compounds found in edible oil and biofuels industries. The data bank used for regression of the group contribution parameters (1395 values...

  18. Extension of the heat flux method to subatmospheric pressures

    NARCIS (Netherlands)

    Bosschaart, K.J.; Goey, de L.P.H.

    2004-01-01

    The heat flux method for measuring laminar burning velocities has been extended to subatmospheric pressures, down to 80mbar. The new setup is described and adaptations necessary for the new conditions are analyzed. This includes a new burner plate to compensate for the decrease of sensitivity of the

  19. Heat bath method for the twisted Eguchi-Kawai model

    International Nuclear Information System (INIS)

    Fabricius, K.; Haan, O.

    1984-01-01

    We reformulate the twisted Eguchi-Kawaii model in a way that allows us to use the heat bath method for the updating procedure of the link matrices. This new formulation is more efficient by a factor of 2.5 in computer time and of 2.3 in memory need. (orig.)

  20. Heat bath method for the twisted Eguchi-Kawai model

    Energy Technology Data Exchange (ETDEWEB)

    Fabricius, K.; Haan, O.

    1984-08-16

    We reformulate the twisted Eguchi-Kawaii model in a way that allows us to use the heat bath method for the updating procedure of the link matrices. This new formulation is more efficient by a factor of 2.5 in computer time and of 2.3 in memory need.

  1. A criterion for heated pipe design by linear electric resistances

    International Nuclear Information System (INIS)

    Bloch, M.; Cruz, J.R.B.

    1984-01-01

    A criterion for linear eletrical elements instalation on horizontal tubes is obtainned in this work. This criterion is based upon the calculation of the thermal stresses caused by the non uniform temperature distribution in the tube cross section. The finite difference method and the SAP IV computer code are both used in the calculations. The criterion is applied to the thermal circuits of the IEN which has tube diameter varying from φ 1/2 in till φ 8 in. (author) [pt

  2. Assessment of the role of oxygen and mitochondria in heat shock induction of radiation and thermal resistance in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.; Morrison, D.P.

    1983-01-01

    In response to a heat shock, the yeast Saccharomyces cerevisiae undergoes a large increase in its resistance to heat and, by the induction of its recombinational DNA repair capacity, a corresponding increase in resistance to radiation. Yeast which lack mitochondrial DNA, mitochondria-controlled protein synthetic apparatus, aerobic respiration, and electron transport (rho 0 strain) were used to assess the role of O 2 , mitochondria, and oxidative processes controlled by mitochondria in the induction of these resistances. We have found that rho 0 yeast grown and heat shocked in either the presence or absence of O 2 are capable of developing both radiation and heat resistance. We conclude that neither the stress signal nor its cellular consequences of induced heat and radiation resistance are directly dependent on O 2 , mitochondrial DNA, or mitochondria-controlled protein synthetic or oxidative processes

  3. Exogenous Salicylic Acid Enhances the Resistance of Wheat Seedlings to Hessian Fly (Diptera: Cecidomyiidae) Infestation Under Heat Stress.

    Science.gov (United States)

    Underwood, Joshua; Moch, John; Chen, Ming-Shun; Zhu, Lieceng

    2014-10-01

    Heat stress exerts significant impact on plant-parasite interactions. Phytohormones, such as salicylic acid (SA), play important roles in plant defense against parasite attacks. Here, we studied the impact of a combination of heat stress and exogenous SA on the resistance of wheat (Triticum aestivum L.) plants to the Hessian fly [Mayetiola destructor (Say)]. We found that the wheat cultivar 'Molly', which contains the resistance gene H13, lost resistance to Hessian fly under heat stress (40°C for 3 and 6 h), and that exogenous application of SA on Molly seedlings right before heat stress can partially prevent the loss of resistance of Molly plants under heat conditions. Our findings have significant implications for understanding the dynamics of plant-insect interactions in the context of heat stress. © 2014 Entomological Society of America.

  4. Method for the positioning of pipes in a heat exchanger

    International Nuclear Information System (INIS)

    1983-01-01

    The invention relates to a method for positioning pipes in a heat exchanger. The grating that supports the pipes of the heat exchanger may be equipped with projections in the passages that also support the pipes. Such projections may, however, obstruct the positioning of the pipes in the grating. The purpose of the invention is to bypass this problem by applying receding projections that move outward when a wedge is put in the grating and thereupon turned round in such a way that the pipes can freely be positioned. Thereupon, the wedge is turned back and the projections will resume their positions. (Auth.)

  5. A multilevel method for conductive-radiative heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Banoczi, J.M.; Kelley, C.T. [North Carolina State Univ., Raleigh, NC (United States)

    1996-12-31

    We present a fast multilevel algorithm for the solution of a system of nonlinear integro-differential equations that model steady-state combined radiative-conductive heat transfer. The equations can be formulated as a compact fixed point problem with a fixed point map that requires both a solution of the linear transport equation and the linear heat equation for its evaluation. We use fast transport solvers developed by the second author, to construct an efficient evaluation of the fixed point map and then apply the Atkinson-Brakhage, method, with Newton-GMRES as the coarse mesh solver, to the full nonlinear system.

  6. Characterization of HEM silicon for solar cells. [Heat Exchanger Method

    Science.gov (United States)

    Dumas, K. A.; Khattak, C. P.; Schmid, F.

    1981-01-01

    The Heat Exchanger Method (HEM) is a promising low-cost ingot casting process for material used for solar cells. This is the only method that is capable of casting single crystal ingots with a square cross section using a directional solidification technique. This paper describes the chemical, mechanical and electrical properties of the HEM silicon material as a function of position within the ingot.

  7. Tick resistance and heat tolerance characteristics in cattle. III. Sweating rate

    Directory of Open Access Journals (Sweden)

    Cecília José Veríssimo

    2012-12-01

    Full Text Available Cattle in a sustainable tropical livestock should be heat tolerant and resistant to ticks. The relationship between Rhipicephalus (Boophilus microplus infestation and sweating rate, an important heat tolerance characteristic, was studied in six Nellore and four Holstein steers of seven-month-old. They were artificial infested (a.i. with 10,000 (Holstein and 20,000 (Nellore larvae in 16/Apr/2011. In days 20, 23 and 24 after the infestation, the 10 bigger females ticks found in whole animal were weighed and put in a chamber (27 oC and 80% RH, weighing the egg mass of each female tick fourteen days after. The sweating rate (SRskin, measured by Scheleger and Turner, 1963, method, in a shaved area of shoulder skin was evaluated in 14/Apr (2 days before the a.i. and in 05/May (19 days after a.i.. In 14/Apr the Scheleger and Turner, 1963, method was done on the coat not shaved (SRcoat. The sweating rate was measured in the afternoon (from 2 P.M., after 30 minutes of direct sunlight, on April. On May, the animals remained 60 minutes in direct sunlight because this day was colder. The experimental design was a non-probability sample restricted to the 10 available animals. Data from the steers’ sweating rate were analyzed using the General linear models of the SPSS® statistical package (version 12.0 using SRskin as dependent variable and breed and sampling date as independent variables. For SRcoat breed was the independent variable. Nellore, a tropical cattle breed, had higher SRskin (1,000.82 ± 64.59 g m-2 h-1, P< 0.001 than Holstein (620.45 ± 79.10 g m-2 h-1. SRskin was higher on May (1,187.33 ± 71.49 g m-2 h-1, P< 0.001 than on April (433.93 ± 71.49 g m-2 h-1. The correlation between the two different measurements of SR was positive and significant (r= 0,545, P<0,01, Pearson correlation. But in SRcoat the breed effect disappeared because the Holstein SRcoat increased (Holstein: 884.95 ± 472.12 g m-2 h-1 and Nellore: 1,060.72 ± 318.21 g m-2 h-1

  8. Global solvability, non-resistive limit and magnetic boundary layer of the compressible heat-conductive MHD equations

    OpenAIRE

    Zhang, Jianwen; Zhao, Xiaokui

    2015-01-01

    In general, the resistivity is inversely proportional to the electrical conductivity, and is usually taken to be zero when the conducting fluid is of extremely high conductivity (e.g., ideal conductors). In this paper, we first establish the global well-posedness of strong solution to an initial-boundary value problem of the one-dimensional compressible, viscous, heat-conductive, non-resistive MHD equations with general heat-conductivity coefficient and large data. Then, the non-resistive lim...

  9. The role of heat resistance in thermorestoration of hydrated bacterial spores

    International Nuclear Information System (INIS)

    Friedman, Y.S.; Grecz, N.

    1973-01-01

    This study for the first time presents evidence of the distinct role played in thermorestoration by cellular determinants such as the resistance to heat and radiation, and the ionic state of spores. In the past only radiochemical determinants associated with radical annealment have been studied in hydrated systems. The basic heat resistance of spores plays a significant role in the precipitous drop in spore survival due to 0.45 Mrad radiation plus heat above 65-75 0 C for B.cereus and 75-95 0 C for B.stearothermophilus. The effect of the spores radiation resistance was not distinct except in the frozen state and at the saturation plateau of thermorestoration where the radiation resistant B.cereus showed ca. 1 log cycle higher survival than the radiation sensitive B.stearothermophilus. When spores are chemically converted into their H + and Ca ++ ionic forms, the H + spores are distinctly more responsive than Ca ++ spores to processes of radical annealment responsible for thermorestoration in hydrated spore systems. At temperatures of extensive thermorestoration of water radicals, H + spores showed higher survival than Ca ++ spores. (F.J.)

  10. Transient, heat-induced thermal resistance in the small intestine of mouse

    International Nuclear Information System (INIS)

    Hume, S.P.; Marigold, J.C.L.

    1980-01-01

    Heat-induced thermal resistance has been investigated in mouse jejunum by assaying crypt survival 24 h after treatment. Hyperthermia was achieved by immersing an exteriorized loop of intestine in a bath of Krebs-Ringer solution. Two approaches have been used. In the first, thermal survival curves were obtained following single hyperthermal treatments at temperatures in the range 42 to 44 0 C. Transient thermal resistance, inducted by a plateau in the crypt survival curve, developed during heating at temperatures around 42.5 0 C after 60 to 80 min. In the second series of experiments, a priming heat treatment (40.0, 41.0, 41.5, or 42.0 0 C for 60 min) was followed at varying intervals by a test treatment at 43.0 0 C. A transient resistance to the second treatment was induced, the extent and time of development being dependent upon the priming treatment. Crypt survival curves for thermally resistant intestine showed an increase in thermal D 0 and a decrease in n compared with curves from previously unheated intestine

  11. Fuel coolant interaction experiment by direct electrical heating method

    International Nuclear Information System (INIS)

    Takeda, Tsuneo; Hirano, Kenmei

    1979-01-01

    In the PCM (Power Cooling Mismatch) experiments, the FCI (Fuel Coolant Interaction) test is one of necessary tests in order to predict various phenomena that occur during PCM in the core. A direct electrical heating method is used for the FCI tests for fuel pellet temperature of over 1000 0 C. Therefore, preheating is required before initiating the direct electrical heating. The fuel pin used in the FCI tests is typical LWR fuel element, which is surrounded by coolant water. It is undersirable to heat up the coolant water during preheating of the fuel pin. Therefore, a zirconia (ZrO 2 ) pellet which is similar to a UO 2 pellet in physical and chemical properties is used. Electric property (electric conductivity) of ZrO 2 is particularly suitable for direct electrical heating as in the case of UO 2 . In this experiment, ZrO 2 pellet (melting point 2500 0 C) melting was achieved by use of both preheating and direct electrical heating. Temperature changes of coolant and fuel surface, as well as the pressure change of coolant water, were measured. The molten fuel interacted with the coolant and generated shock waves. A portion of this molten fuel fragmented into small particles during this interaction. The peak pressure of the observed shock wave was about 35 bars. The damaged fuel pin was photographed after disassembly. This report shows the measured coolant pressure changes and the coolant temperature changes, as well as photographs of damaged fuel pin and fuel fragments. (author)

  12. Method and means for heating buildings in a district heating system with waste heat from a thermal power plant

    International Nuclear Information System (INIS)

    Margen, P.H.E.

    1975-01-01

    The waste heat from a thermal power plant is transported through a municipal heating network to a plurality of buildings to be heated. The quantity of heat thus supplied to the buildings is higher than that required for the heating of the buildings. The excess heat is released from the buildings to the atmosphere in the form of hot air

  13. Resistive wall heating due to image current on the beam chamber for a superconducting undulator.

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. H. (Accelerator Systems Division (APS))

    2012-03-27

    The image-current heating on the resistive beam chamber of a superconducting undulator (SCU) was calculated based on the normal and anomalous skin effects. Using the bulk resistivity of copper for the beam chamber, the heat loads were calculated for the residual resistivity ratios (RRRs) of unity at room temperature to 100 K at a cryogenic temperature as the reference. Then, using the resistivity of the specific aluminum alloy 6053-T5, which will be used for the SCU beam chamber, the heat loads were calculated. An electron beam stored in a storage ring induces an image current on the inner conducting wall, mainly within a skin depth, of the beam chamber. The image current, with opposite charge to the electron beam, travels along the chamber wall in the same direction as the electron beam. The average current in the storage ring consists of a number of bunches. When the pattern of the bunched beam is repeated according to the rf frequency, the beam current may be expressed in terms of a Fourier series. The time structure of the image current is assumed to be the same as that of the beam current. For a given resistivity of the chamber inner wall, the application ofthe normal or anomalous skin effect will depend on the harmonic numbers of the Fourier series of the beam current and the temperature of the chamber. For a round beam chamber with a ratius r, much larger than the beam size, one can assume that the image current density as well as the density square, may be uniform around the perimeter 2{pi}r. For the SCU beam chamber, which has a relatively narrow vertical gap compared to the width, the effective perimeter was estimated since the heat load should be proportional to the inverse of the perimeter.

  14. An Experimental Study on Heat Conduction and Thermal Contact Resistance for the AlN Flake

    Directory of Open Access Journals (Sweden)

    Huann-Ming Chou

    2013-01-01

    Full Text Available The electrical technology has been a fast development over the past decades. Moreover, the tendency of microelements and dense division multiplex is significantly for the electrical industries. Therefore, the high thermal conductible and electrical insulating device will be popular and important. It is well known that AlN still maintains stablility in the high temperature. This is quite attractive for the research and development department. Moreover, the thermal conduct coefficient of AlN is several times larger than the others. Therefore, it has been thought to play an important role for the radiator of heat source in the future. Therefore, this paper is focused on the studies of heat conduction and thermal contact resistance between the AlN flake and the copper specimens. The heating temperatures and the contact pressures were selected as the experimental parameters. According to the experimental results, the materials are soft and the real contact areas between the interfaces significantly increase under higher temperatures. As a result, the thermal contact resistance significantly decreases and the heat transfer rate increases with increasing the heating temperature or the contact pressures.

  15. Hybrid joining of polyamide and hydrogenated acrylonitrile butadiene rubber through heat-resistant functional layer of silane coupling agent

    Energy Technology Data Exchange (ETDEWEB)

    Sang, Jing; Sato, Riku [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Aisawa, Sumio, E-mail: aisawa@iwate-u.ac.jp [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Hirahara, Hidetoshi [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Mori, Kunio [Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Sulfur Chemical Institute, 210, Collabo MIU, 4-3-5, Ueda, Morioka 020-0066 (Japan)

    2017-08-01

    Highlights: • We modify PA6 surface using silane coupling agent layer of APTMS to link HNBR. • APTMS greatly improved heat resistance of PA6 from 153 °C up to 325 °C. • A PA6/HNBR joined body was obtained, and it exhibits high adhesion strength with cohesive failure. • Chemical structures of the adhesion interfaces of PA6/HNBR were confirmed by Nano-IR. - Abstract: A simple, direct adhesion method was developed to join polyamide (PA6) to hydrogenated acrylonitrile butadiene rubber (HNBR) by grafting a functional layer of a silane coupling agent on plasma functionalized PA6 surfaces. The functional layer of the silane coupling agent was prepared using a self-assembly method, which greatly improved the heat resistance of PA6 from 153 °C up to 325 °C and the resulting PA6/HNBR joints showed excellent adhesion properties with cohesive failure between PA6 and HNBR. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and nanoscale infrared microscopy and chemical imaging (Nano-IR, AFM-IR) were employed to characterize the surfaces and interfaces. The Nano-IR analysis method was employed for the first time to analyze the chemical structures of the adhesion interfaces between different materials and to establish the interface formation mechanism. This study is of significant value for interface research and the study of adhesion between resins and rubbers. There is a promising future for heat-resistant functional layers on resin surfaces, with potential application in fuel hose composite materials for the automotive and aeronautical industries.

  16. A Study on the Improvement Effect and Field Applicability of the Deep Soft Ground by Ground Heating Method

    Directory of Open Access Journals (Sweden)

    Mincheol Park

    2018-05-01

    Full Text Available The soft ground in coastal areas should be treated when it needs to be used for the sustainably developed of urban or industrial complex constructions. The ground heating method for soft ground improvement was applied in Eastern Europe in the 1960s, but it was not widely used due to economic and environmental problems. The author developed a device for improving soft ground using an electric heating pipe. This paper investigates the improvement effect and field application of deep soft ground by the ground heating method using the electric heating pipe. Ground heating increases the temperature of the deep soft ground and increases the tip resistance of the static electronic piezo-cone penetration test. Additionally, the pressure of the pore water decreases because the pore water is evaporated due to the ground heating. As a result of the experiment, it was verified that there was an improvement in the effect of deep soft ground by the ground heating method. With ground heating for 96 h, the tip resistance was increased by 61% at a point 0.35 m horizontally away from the electric heat pipe, 22% at 0.97 m, and 2% at 1.31 m. As a result of the field test, it was found that there were no problems in the power supply of the diesel generator and the control panel. It was easy to install the electric heating pipes in the deep soft ground. However, due to boring, the ground was disturbed and water vapor was discharged through this gap. To minimize the discharge of water vapor, it is necessary to drive the electric heating pipe.

  17. Fracture properties and heat resistance of ceramics consisting of microspheres of stabilized zirconium dioxide

    International Nuclear Information System (INIS)

    Krasulin, Yu.L.; Barinov, S.M.; Ivanov, A.B.; Timofeev, V.N.; Grevtsev, S.N.; Ivanov, D.A.

    1980-01-01

    Determined were effective specific fracture work, critical coefficient of stress intensity in the upper point of the fracture, strength and heat resistance during heat changes (20-1300 deg C) of the material produced by sintering stabilized zirconium dioxide microspheres. Dependence of these characteristics on granulometric composition of microspheres was determined. It was ascertained that the additional introduction of large microspheres into the bulk of small microspheres increased the metal fracture work. Specific work of material fracture progress exceeded specific work of fracture motion initiation. High value of fracture work together with high strength permits to use the material formed of microspheres as structural ceramics

  18. Heat dissipation due to ferromagnetic resonance in a ferromagnetic metal monitored by electrical resistance measurement

    International Nuclear Information System (INIS)

    Yamanoi, Kazuto; Yokotani, Yuki; Kimura, Takashi

    2015-01-01

    The heat dissipation due to the resonant precessional motion of the magnetization in a ferromagnetic metal has been investigated. We demonstrated that the temperature during the ferromagnetic resonance can be simply detected by the electrical resistance measurement of the Cu strip line in contact with the ferromagnetic metal. The temperature change of the Cu strip due to the ferromagnetic resonance was found to exceed 10 K, which significantly affects the spin-current transport. The influence of the thermal conductivity of the substrate on the heating was also investigated

  19. Heat Conduction Analysis Using Semi Analytical Finite Element Method

    International Nuclear Information System (INIS)

    Wargadipura, A. H. S.

    1997-01-01

    Heat conduction problems are very often found in science and engineering fields. It is of accrual importance to determine quantitative descriptions of this important physical phenomena. This paper discusses the development and application of a numerical formulation and computation that can be used to analyze heat conduction problems. The mathematical equation which governs the physical behaviour of heat conduction is in the form of second order partial differential equations. The numerical resolution used in this paper is performed using the finite element method and Fourier series, which is known as semi-analytical finite element methods. The numerical solution results in simultaneous algebraic equations which is solved using the Gauss elimination methodology. The computer implementation is carried out using FORTRAN language. In the final part of the paper, a heat conduction problem in a rectangular plate domain with isothermal boundary conditions in its edge is solved to show the application of the computer program developed and also a comparison with analytical solution is discussed to assess the accuracy of the numerical solution obtained

  20. QTL for the thermotolerance effect of heat hardening, knowckdown resistance to heat and chill-coma recovery in an intercontinental set of recombinant inbred lines of Drosophila melanogaster

    DEFF Research Database (Denmark)

    Norry, Fabian M.; Scannapieco, Alejandra C.; Sambucetti, Pablo

    2008-01-01

    The thermotolerance effect of heat hardening (also called short-term acclimation), knockdown resistance to high temperature (KRHT) with and without heat hardening and chill-coma recovery (CCR) are important phenotypes of thermal adaptation in insects and other organisms. Drosophila melanogaster...

  1. The Use of Resistivity Methods in Terrestrial Forensic Searches

    Science.gov (United States)

    Wolf, R. C.; Raisuddin, I.; Bank, C.

    2013-12-01

    The increasing use of near-surface geophysical methods in forensic searches has demonstrated the need for further studies to identify the ideal physical, environmental and temporal settings for each geophysical method. Previous studies using resistivity methods have shown promising results, but additional work is required to more accurately interpret and analyze survey findings. The Ontario Provincial Police's UCRT (Urban Search and Rescue; Chemical, Biolgical, Radiological, Nuclear and Explosives; Response Team) is collaborating with the University of Toronto and two additional universities in a multi-year study investigating the applications of near-surface geophysical methods to terrestrial forensic searches. In the summer of 2012, on a test site near Bolton, Ontario, the OPP buried weapons, drums and pigs (naked, tarped, and clothed) to simulate clandestine graves and caches. Our study aims to conduct repeat surveys using an IRIS Syscal Junior with 48 electrode switching system resistivity-meter. These surveys will monitor changes in resistivity reflecting decomposition of the object since burial, and identify the strengths and weaknesses of resistivity when used in a rural, clandestine burial setting. Our initial findings indicate the usefulness of this method, as prominent resistivity changes have been observed. We anticipate our results will help to assist law enforcement agencies in determining the type of resistivity results to expect based on time since burial, depth of burial and state of dress of the body.

  2. Development of heat resistant Pb-free joints by TLPS process of Ag and Sn-Bi-Ag alloy powders

    Directory of Open Access Journals (Sweden)

    Ohnuma I.

    2012-01-01

    Full Text Available TLPS (Transient Liquid Phase Sintering process is a candidate method of heat-resistant bonding, which makes use of the reaction between low-melting temperature powder of Sn-Bi base alloys and reactive powder of Ag. During heat treatment above the melting temperature of a Sn-Bi base alloy, the molten Sn-Bi reacts rapidly with solid Ag particles, which results in the formation of heat-resistant intermetallic compound (IMC. In this study, the TLPS properties between Sn-17Bi-1Ag (at.% powder with its liquidus temperature of 200°C and pure Ag powder were investigated. During differential scanning calorimetry (DSC measurement, an exothermic reaction and an endothermic reaction occurred, which correspond to the formation of the e-Ag3Sn IMC phase and the melting of the Sn-17Bi-1Ag alloy, respectively. After the overall measurement, the obtained reactant consists of the Ag3Sn-IMC and Bi-rich phases, both of which start melting above 250°C, with a small amount of the residual Sn-Bi eutectic phase. These results suggest that the TLPS process can be applied for Pb-free heatresistant bonding.

  3. Erosion resistance in a stationary arc of powder materials on the base of heat resisting alloys

    Energy Technology Data Exchange (ETDEWEB)

    Minakova, R.V.; Kostenetskaya, L.I.; Krusanova, A.P.; Kukhtikov, V.A.; Smirnov, A.V.; Lugovskaya, E.S. (AN Ukrainskoj SSR, Kiev. Inst. Problem Materialovedeniya)

    1983-08-01

    Comparison investigations of some properties of the Mo-Cu, Mo-Ni(Co)-Cu materials and the W-Cu, W-Ni-Cu compositions used at the present time as well as contact pairs prepared from them is conducted. It is shown that electroerosion wear of the contacts is connected not only with the material properties but also with features of structural changes in the working layer under effect of arc discharge. It is shown also that directed alloying with respect to the origin of phase transition in the electrode material and the medium effect during current commutation promotes electroerosion resistance.

  4. Erosion resistance in a stationary arc of powder materials on the base of heat resisting alloys

    International Nuclear Information System (INIS)

    Minakova, R.V.; Kostenetskaya, L.I.; Krusanova, A.P.; Kukhtikov, V.A.; Smirnov, A.V.; Lugovskaya, E.S.

    1983-01-01

    Comparison investigations of some properties of the Mo-Cu, Mo-Ni(Co)-CU materials and the W-CU, W-Ni-CU compositions used at the present time as well as contact pairs prepared from them is conducted. It is shown that electroerosion wear of the contacts is connected not only with the material properties but also with features of structural changes in the working layer under effect of arc discharge. It in shown s also that directed alloying with respect to the origin of phase transition in the electrode material and the medium effect during current commutation promotes electroerosion resistance

  5. Resistive vs. total power depositions by Alfven modes in pre-heated low aspect ratio tokamaks

    International Nuclear Information System (INIS)

    Cuperman, S.; Bruma, C.; Komoshvili, K.

    2004-01-01

    The power deposition of fast waves launched by a LFS located antenna in a pre-heated, strongly non-uniform low aspect ratio tokamak (START) is investigated. The rigorous computational results indicate a total power deposition by far larger than that predicted for Alfven continuum eigenmodes in cylindrical plasmas. For toroidal wave numbers |N| > 1, the resistive and total power depositions are almost equal. (author)

  6. Recirculation within a glass mixture subjected to external and resistive heating

    International Nuclear Information System (INIS)

    Pepper, D.W.

    1985-01-01

    Convective motion within a glass mixture undergoing external and resistive (joule) heating is numerically simulated. A time-split finite element technique and a pseudo-pressure formulation are used to solve the two- and three-dimensional primitive equations of motion. The viscosity, thermal diffusivity, and electrical conductivity vary as a function of temperature; the temperature varies from ambient to 1150 0 C. 15 refs., 4 figs

  7. Influenced prior loading on the creep fatigue damage accumulation of heat resistant steels

    International Nuclear Information System (INIS)

    Kloos, K.H.; Granacher, J.; Scholz, A.

    1990-01-01

    On two heat resistant power plant steels the influence of prior strain cycling on the creep rupture behaviour and the influence of prior creep loading on the strain cycling behaviour is investigated. These influences concern the number of cycles to failure and the rupture time being the reference values of the generalized damage accumulation rule and they are used for a creep fatigue analysis of the results of long term service-type strain cycling tests. (orig.) [de

  8. Efficient numerical method for district heating system hydraulics

    International Nuclear Information System (INIS)

    Stevanovic, Vladimir D.; Prica, Sanja; Maslovaric, Blazenka; Zivkovic, Branislav; Nikodijevic, Srdjan

    2007-01-01

    An efficient method for numerical simulation and analyses of the steady state hydraulics of complex pipeline networks is presented. It is based on the loop model of the network and the method of square roots for solving the system of linear equations. The procedure is presented in the comprehensive mathematical form that could be straightforwardly programmed into a computer code. An application of the method to energy efficiency analyses of a real complex district heating system is demonstrated. The obtained results show a potential for electricity savings in pumps operation. It is shown that the method is considerably more effective than the standard Hardy Cross method still widely used in engineering practice. Because of the ease of implementation and high efficiency, the method presented in this paper is recommended for hydraulic steady state calculations of complex networks

  9. Tropical Drosophila ananassae of wet-dry seasons show cross resistance to heat, drought and starvation

    Directory of Open Access Journals (Sweden)

    Chanderkala Lambhod

    2017-11-01

    Full Text Available Plastic responses to multiple environmental stressors in wet or dry seasonal populations of tropical Drosophila species have received less attention. We tested plastic effects of heat hardening, acclimation to drought or starvation, and changes in trehalose, proline and body lipids in Drosophila ananassae flies reared under wet or dry season-specific conditions. Wet season flies revealed significant increase in heat knockdown, starvation resistance and body lipids after heat hardening. However, accumulation of proline was observed only after desiccation acclimation of dry season flies while wet season flies elicited no proline but trehalose only. Therefore, drought-induced proline can be a marker metabolite for dry-season flies. Further, partial utilization of proline and trehalose under heat hardening reflects their possible thermoprotective effects. Heat hardening elicited cross-protection to starvation stress. Stressor-specific accumulation or utilization as well as rates of metabolic change for each energy metabolite were significantly higher in wet-season flies than dry-season flies. Energy metabolite changes due to inter-related stressors (heat versus desiccation or starvation resulted in possible maintenance of energetic homeostasis in wet- or dry-season flies. Thus, low or high humidity-induced plastic changes in energy metabolites can provide cross-protection to seasonally varying climatic stressors.

  10. Resistance of heat resisting steels and alloys to thermal and mechanical low-cycle fatigue

    International Nuclear Information System (INIS)

    Tulyakov, G.A.

    1980-01-01

    Carried out is a comparative evalUation of resistance of different materials to thermocyclic deformation and fracture on the base of the experimental data on thermal and mechanical low-cycle fatigUe. Considered are peculiarities of thermal fatigue resistance depending on strength and ductility of the material. It is shown, that in the range of the cycle small numbers before the fracture preference is given to the high-ductility cyclically strengthening austenitic steels of 18Cr-10Ni type with slight relation of yield strength to the σsub(0.2)/σsub(B) tensile strength Highly alloyed strength chromium-nickel steels, as well as cyclically destrengthening perlitic and ferritic steels with stronger σsub(0.2)/σsub(B) relation as compared with simple austenitic steels turn to be more long-lived in the range of the cycle great numbers berore fracture. Perlitic steels are stated to have the lowest parameter values of the K crack growth intensity under the similar limiting conditions of the experiment, while steels and alloys with austenite structure-higher values of the K parameter

  11. Electromagnetic heating method to improve steam assisted gravity drainage

    Energy Technology Data Exchange (ETDEWEB)

    Koolman, M.; Huber, N.; Diehl, D.; Wacker, B. [Siemens AG, Munich (Germany)

    2008-10-15

    The in-situ recovery of heavy and highly viscous bitumen has become economically feasible with the use of steam assisted gravity drainage (SAGD). However, several challenges exist, such as the energy cost for production of bitumen; environmental concerns over the consumption of water; limited recovery of bitumen; shallowness of the reservoirs; and the propagation of steam chambers leading to limited recovery. This paper described an opportunity to improve the widely applied SAGD process for in-situ production of bitumen from oil sands deposits. The technical concept was directed at electromagnetic (EM-SAGD) heating methods assisting the process. The paper described a preliminary investigation that was conducted in order to confirm the feasibility of different solutions and evaluate aspects of energy efficiency and environmental impact. A comparison of electrical heating methods showed that the inductive method was the most reasonable in terms of technical and economical feasibility. The paper also discussed a small scale sandbox test to verify a three-dimensional simulation provided with two different simulation tools. The results of reservoir simulation were also presented. Last, the paper examined health and safety considerations. It was concluded that inductive heating provides an additional, easy to handle control parameter. The study showed that if the geometries of the inductors related to the producer wells were selected in a tailor-made manner, individual reservoir conditions could be handled by an optimized operating strategy. 4 refs., 3 tabs., 15 figs.

  12. Wettability and interface considerations in advanced heat-resistant Ni-base composites

    International Nuclear Information System (INIS)

    Asthana, R.; Mileiko, S.T.; Sobczak, N.

    2006-01-01

    Oxide fiber-reinforced Ni-base composites have long been considered as attractive heat-resistant materials. After several decades of active research, however, interest in these materials began to decline around mid-1990's due chiefly to 1) a lack of manufacturing technology to grow inexpensive single-crystal oxide fibers to be used in structural composites, and 2) fiber strength loss during processing due to chemical interactions with reactive solutes in the matrix. The cost disadvantage has been mitigated to a large extent by the development of innovative fiber fabrication processes such as the Internal Crystallization Method (ICM) that produces monocrystalline oxide fibers in a cost-effective manner. Fiber strength loss has been an equally restrictive issue but recent work has shown that it may be possible to design creep-resistant composites even when fiber surface reconstruction from chemical interactions has degraded the strength of extracted fibers tested outside the matrix. The key issue is the optimization of the composite- and interface structure. Reaction-formed defects may be healed by the matrix (or a suitable coating material) so that the fiber residing in the matrix may exhibit diminished sensitivity to flaws as compared to fibers extracted from the matrix and tested in isolation of the matrix. Generally, the Ni-base/Al 2 O 3 composites exhibit acceptable levels of wettability and interface strength (further improved with the aid of reactive solutes), which are required for elevated-temperature creep-resistance. In order to harness the full potential of these composites, the quality of the interface as manifested in the fiber/matrix wettability, interface composition, interphase morphology, and interface strength must be designed. We identify key issues related to the measurement of contact angle, interface strength, and chemical and structural properties at the fiber/matrix interface in the Ni/alumina composites, and present the current state-of the

  13. Hybrid joining of polyamide and hydrogenated acrylonitrile butadiene rubber through heat-resistant functional layer of silane coupling agent

    Science.gov (United States)

    Sang, Jing; Sato, Riku; Aisawa, Sumio; Hirahara, Hidetoshi; Mori, Kunio

    2017-08-01

    A simple, direct adhesion method was developed to join polyamide (PA6) to hydrogenated acrylonitrile butadiene rubber (HNBR) by grafting a functional layer of a silane coupling agent on plasma functionalized PA6 surfaces. The functional layer of the silane coupling agent was prepared using a self-assembly method, which greatly improved the heat resistance of PA6 from 153 °C up to 325 °C and the resulting PA6/HNBR joints showed excellent adhesion properties with cohesive failure between PA6 and HNBR. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and nanoscale infrared microscopy and chemical imaging (Nano-IR, AFM-IR) were employed to characterize the surfaces and interfaces. The Nano-IR analysis method was employed for the first time to analyze the chemical structures of the adhesion interfaces between different materials and to establish the interface formation mechanism. This study is of significant value for interface research and the study of adhesion between resins and rubbers. There is a promising future for heat-resistant functional layers on resin surfaces, with potential application in fuel hose composite materials for the automotive and aeronautical industries.

  14. Significant effect of Ca2+ on improving the heat resistance of lactic acid bacteria.

    Science.gov (United States)

    Huang, Song; Chen, Xiao Dong

    2013-07-01

    The heat resistance of lactic acid bacteria (LAB) has been extensively investigated due to its highly practical significance. Reconstituted skim milk (RSM) has been found to be one of the most effective protectant wall materials for microencapsulating microorganisms during convective drying, such as spray drying. In addition to proteins and carbohydrate, RSM is rich in calcium. It is not clear which component is critical in the RSM protection mechanism. This study investigated the independent effect of calcium. Ca(2+) was added to lactose solution to examine its influence on the heat resistance of Lactobacillus rhamnosus ZY, Lactobacillus casei Zhang, Lactobacillus plantarum P8 and Streptococcus thermophilus ND03. The results showed that certain Ca(2+) concentrations enhanced the heat resistance of the LAB strains to different extents, that is produced higher survival and shorter regrowth lag times of the bacterial cells. In some cases, the improvements were dramatic. More scientifically insightful and more intensive instrumental study of the Ca(2+) behavior around and in the cells should be carried out in the near future. In the meantime, this work may lead to the development of more cost-effective wall materials with Ca(2+) added as a prime factor. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  15. Role of Ca ions in the induction of heat-resistance of wheat coleoptiles by brassinosteroids

    Directory of Open Access Journals (Sweden)

    Yu. E. Kolupaev

    2015-02-01

    Full Text Available The involvement of Ca2+ into the signal transduction of exogenous brassinosteroids (BS (24-epibrassinolide – 24-EBL and 24-epicastasterone – 24 ECS causing the increase of heat resistance of the cells of wheat (Triticum aestivum L. coleoptiles was investigated using calcium chelator EGTA and inhibitor of phosphatidylinositol-specific phospholipase C – neomycin. Twenty-four-hour treatment of coleoptile segments with 10 nM solutions of 24-EBL and 24-ECS led to a transient increase in the generation of superoxide anion radical by cell surface and the subsequent activation of superoxide dismutase and catalase. Pretreatment of coleoptiles with EGTA and neomycin depressed to a considerable extent these effects and leveled the increase in heat resistance of wheat coleoptiles that were caused by BS. Possible mechanisms of involvement of calcium signaling into the formation of reactive oxygen species in plant cells and induction of heat resistance of plant cells by the action of exogenous BS have been discussed.

  16. Heat-shock induction of ionizing radiation resistance in Saccharomyces cerevisiae, and the correlation with stationary growth phase

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.; Morrison, D.P.

    1982-01-01

    Radiation resistance and thermal resistance vary as a function of culture temperature in logarithmically growing Saccharomyces cerevisiae and are related to the optimum temperature for growth. Radiation resistance and thermal resistance were also induced when cells grown at low temperatures were subjected to a heat shock at or above the optimum growth temperature. Exposure to ionizing radiation followed by a short incubation at low temperature also induced resistance to killing by heat. Heat-shocked cells are induced to a level of thermal and radioresistance much greater than the characteristic resistance level of cells grown continuously at the shock temperature. This high level of resistance, which resembles that of stationary-phase cells, decays to the characteristic log-phase level within one doubling of cell number after the heat shock. Both induction of resistance and decay of that induction require protein synthesis. It is postulated that induction of resistance by heat shock or ionizing radiation is a response of the cells to stress and represents a preparation to enter stationary phase

  17. Determination of slope failure using 2-D resistivity method

    Science.gov (United States)

    Muztaza, Nordiana Mohd; Saad, Rosli; Ismail, Nur Azwin; Bery, Andy Anderson

    2017-07-01

    Landslides and slope failure may give negative economic effects including the cost to repair structures, loss of property value and medical costs in the event of injury. To avoid landslide, slope failure and disturbance of the ecosystem, good and detailed planning must be done when developing hilly area. Slope failure classification and various factors contributing to the instability using 2-D resistivity survey conducted in Selangor, Malaysia are described. The study on landslide and slope failure was conducted at Site A and Site B, Selangor using 2-D resistivity method. The implications of the anticipated ground conditions as well as the field observation of the actual conditions are discussed. Nine 2-D resistivity survey lines were conducted in Site A and six 2-D resistivity survey lines with 5 m minimum electrode spacing using Pole-dipole array were performed in Site B. The data were processed using Res2Dinv and Surfer10 software to evaluate the subsurface characteristics. 2-D resistivity results from both locations show that the study areas consist of two main zones. The first zone is alluvium or highly weathered with the resistivity of 100-1000 Ωm at 20-70 m depth. This zone consists of saturated area (1-100 Ωm) and boulders with resistivity value of 1200-3000 Ωm. The second zone with resistivity values of > 3000 Ωm was interpreted as granitic bedrock. The study area was characterized by saturated zones, highly weathered zone, highly contain of sand and boulders that will trigger slope failure in the survey area. Based on the results obtained from the study findings, it can be concluded that 2-D resistivity method is useful method in determination of slope failure.

  18. Heat enhancement of radiation resistivity of evaporated CsI, KI and KBr photocathodes

    CERN Document Server

    Tremsin, A S

    2000-01-01

    The photoemissive stability of as-deposited and heat-treated CsI, KI and KBr evaporated thin films under UV radiation is examined in this paper. After the deposition, some photocathodes were annealed for several hours at 90 deg. C in vacuum and their performance was then compared to the performance of non-heated samples. We observed that the post-evaporation thermal treatment not only increases the photoyield of CsI and KI photocathodes in the spectral range of 115-190 nm, but also reduces CsI, KI and KBr photocurrent degradation that occurs after UV irradiation. KBr evaporated layers appeared to be more radiation-resistant than CsI and KI layers. Post-deposition heat treatment did not result in any significant variation of KBr UV sensitivity.

  19. Pipeline heating method based on optimal control and state estimation

    Energy Technology Data Exchange (ETDEWEB)

    Vianna, F.L.V. [Dept. of Subsea Technology. Petrobras Research and Development Center - CENPES, Rio de Janeiro, RJ (Brazil)], e-mail: fvianna@petrobras.com.br; Orlande, H.R.B. [Dept. of Mechanical Engineering. POLI/COPPE, Federal University of Rio de Janeiro - UFRJ, Rio de Janeiro, RJ (Brazil)], e-mail: helcio@mecanica.ufrj.br; Dulikravich, G.S. [Dept. of Mechanical and Materials Engineering. Florida International University - FIU, Miami, FL (United States)], e-mail: dulikrav@fiu.edu

    2010-07-01

    In production of oil and gas wells in deep waters the flowing of hydrocarbon through pipeline is a challenging problem. This environment presents high hydrostatic pressures and low sea bed temperatures, which can favor the formation of solid deposits that in critical operating conditions, as unplanned shutdown conditions, may result in a pipeline blockage and consequently incur in large financial losses. There are different methods to protect the system, but nowadays thermal insulation and chemical injection are the standard solutions normally used. An alternative method of flow assurance is to heat the pipeline. This concept, which is known as active heating system, aims at heating the produced fluid temperature above a safe reference level in order to avoid the formation of solid deposits. The objective of this paper is to introduce a Bayesian statistical approach for the state estimation problem, in which the state variables are considered as the transient temperatures within a pipeline cross-section, and to use the optimal control theory as a design tool for a typical heating system during a simulated shutdown condition. An application example is presented to illustrate how Bayesian filters can be used to reconstruct the temperature field from temperature measurements supposedly available on the external surface of the pipeline. The temperatures predicted with the Bayesian filter are then utilized in a control approach for a heating system used to maintain the temperature within the pipeline above the critical temperature of formation of solid deposits. The physical problem consists of a pipeline cross section represented by a circular domain with four points over the pipe wall representing heating cables. The fluid is considered stagnant, homogeneous, isotropic and with constant thermo-physical properties. The mathematical formulation governing the direct problem was solved with the finite volume method and for the solution of the state estimation problem

  20. Method for making low-resistivity contacts to high T/sub c/ superconductors

    International Nuclear Information System (INIS)

    Ekin, J.W.; Panson, A.J.; Blankenship, B.A.

    1988-01-01

    A method for making low-resistivity contacts to high T/sub c/ superconductors has been developed, which has achieved contact surface resistivities less than 10 μΩ cm 2 at 76 K and does not require sample heating above ∼150 0 C. This is an upper limit for the contact resistivity obtained at high current densities up to 10 2 --10 3 A/cm 2 across the contact interface. At lower measuring current densities the contact resistivities were lower and the voltage-current curve was nonlinear, having a superconducting transition character. On cooling from 295 to 76 K, the contact resistivity decreased several times, in contrast to indium solder contacts where the resistivity increased on cooling. The contacts showed consistently low resistivity and little degradation when exposed to dry air over a four-month period and when repeatedly cycled between room temperature and 76 K. The contacts are formed by sputter depositing a layer of a noble metal-silver and gold were used-on a clean superconductor surface to protect the surface and serve as a contact pad. External connections to the contact pads have been made using both solder and wire-bonding techniques

  1. A Novel Method of Modeling the Deformation Resistance for Clad Sheet

    International Nuclear Information System (INIS)

    Hu Jianliang; Yi Youping; Xie Mantang

    2011-01-01

    Because of the excellent thermal conductivity, the clad sheet (3003/4004/3003) of aluminum alloy is extensively used in various heat exchangers, such as radiator, motorcar air conditioning, evaporator, and so on. The deformation resistance model plays an important role in designing the process parameters of hot continuous rolling. However, the complex behaviors of the plastic deformation of the clad sheet make the modeling very difficult. In this work, a novel method for modeling the deformation resistance of clad sheet was proposed by combining the finite element analysis with experiments. The deformation resistance model of aluminum 3003 and 4004 was proposed through hot compression test on the Gleeble-1500 thermo-simulation machine. And the deformation resistance model of clad sheet was proposed through finite element analysis using DEFORM-2D software. The relationship between cladding ratio and the deformation resistance was discussed in detail. The results of hot compression simulation demonstrate that the cladding ratio has great effects on the resistance of the clad sheet. Taking the cladding ratio into consideration, the mathematical model of the deformation resistance for clad sheet has been proved to have perfect forecasting precision of different cladding ratio. Therefore, the presented model can be used to predict the rolling force of clad sheet during the hot continuous rolling process.

  2. Investigating thermomechanical parameters of the EhP693VD heat resisting alloys deformation

    International Nuclear Information System (INIS)

    Garibov, G.S.; Galkin, A.M.; Ermanok, M.Z.; Trepilets, A.E.

    1975-01-01

    The purpose of the present publication consists in complex research of the deformation resistance and plastic characteristics of heat-resistant hard-to-form alloy EhP693VD at the temperatures and deformation rates peculiar for the pressing process. The test conditions are: temperature 1000 to 1200 deg C; rate of deformation 0.5, 5.0 and 25 s -1 . The curves of deformation hardening of alloy EhP693VD show that the alloy is characterized by very high values of forming resistance index Ssub(f). With the increase of the rates of deformation, the maximum of curves Ssub(f) /antiepsilon/ is shifted towards greater degrees of deformation. The increase of the temperature results in the lower deformation hardening of the alloy. The intensity of the growth of the deformation resistance with the decrease of temperature becomes higher at lower degrees of deformation. Variation of plasticity at temperatures of up to 1150 deg C correlates with the curves showing variation of the deformation resistance. At a temperature of 1200 deg C, the drop of the deformation resistance is accompanied by the intensive drop of the plastic characteristics. The planning matrices, test results and complete disperse analysis tables are given. The analysis of the obtained equations makes it possible to draw a conclusion that the rise of the test temperature and drop of the rates of deformation entail the increase of the plastic characteristics

  3. Beam heat load due to geometrical and resistive wall impedance in COLDDIAG

    Science.gov (United States)

    Casalbuoni, S.; Migliorati, M.; Mostacci, A.; Palumbo, L.; Spataro, B.

    2012-11-01

    One of the still open issues for the development of superconductive insertion devices is the understanding of the heat intake from the electron beam. With the aim of measuring the beam heat load to a cold bore and the hope to gain a deeper understanding in the underlying mechanisms, a cold vacuum chamber for diagnostics (COLDDIAG) was built. It is equipped with the following instrumentation: retarding field analyzers to measure the electron flux, temperature sensors to measure the beam heat load, pressure gauges, and mass spectrometers to measure the gas content. Possible beam heat load sources are: synchrotron radiation, wakefield effects due to geometrical and resistive wall impedance and electron/ion bombardment. The flexibility of the engineering design will allow the installation of the cryostat in different synchrotron light sources. COLDDIAG was first installed in the Diamond Light Source (DLS) in 2011. Due to a mechanical failure of the thermal transition of the cold liner, the cryostat had to be removed after one week of operation. After having implemented design changes in the thermal liner transition, COLDDIAG has been reinstalled in the DLS at the end of August 2012. In order to understand the beam heat load mechanism it is important to compare the measured COLDDIAG parameters with theoretical expectations. In this paper we report on the analytical and numerical computation of the COLDDIAG beam heat load due to coupling impedances deriving from unavoidable step transitions, ports used for pumping and diagnostics, surface roughness, and resistive wall. The results might have an important impact on future technological solutions to be applied to cold bore devices.

  4. Effect of Heat treatment on Hardness and Corrosion Resistance of Super Cast Iron

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Roun; Kim, Young Sik [Andong National University, Andong (Korea, Republic of)

    2014-07-15

    In fossil-fuel-fired power plants, a variety of pollutants are produced from the combustion of conventional fuels such as coal, oil and gas. Major component of such pollution are ash and corrosive chemicals, which also destroy pumps and piping; by causing erosion/corrosion, pitting, and wear. In order to over come such damage, materials with high hardness and high corrosion resistance are needed. In this work, we melted super-cast-iron with excellent corrosion resistance and high hardness. To elucidate the effect of heat treatment, microstructural analysis, hardness measurement, and corrosion tests were performed. Test results revealed that the super-cast-iron had several tens better corrosion resistance than 316 L stainless steel, and it also had a high surface hardness (> HRC45). High hardness, in spite of its low carbon content (0.74%C), could resulted from a hardening heat treatment to precipitate sufficient Cr{sub 7}C{sub 3} and Cr{sub 2}3C{sub 6}. Also, it was concluded that the excellent corrosion resistance of the super-cast-iron was due to the increase of the relative chromium content by minimizing the carbon content, and by the enhancement of passive film by the addition of Cr, Mo, Cu, and W.

  5. A meshless method for modeling convective heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Carrington, David B [Los Alamos National Laboratory

    2010-01-01

    A meshless method is used in a projection-based approach to solve the primitive equations for fluid flow with heat transfer. The method is easy to implement in a MATLAB format. Radial basis functions are used to solve two benchmark test cases: natural convection in a square enclosure and flow with forced convection over a backward facing step. The results are compared with two popular and widely used commercial codes: COMSOL, a finite element model, and FLUENT, a finite volume-based model.

  6. Method of increased bioethanol concentration with reduced heat consumption

    International Nuclear Information System (INIS)

    Bremers, G.; Blija, A.

    2003-01-01

    Ethanol dehydration applying method of non-reflux saline distillation was conduced on a laboratory scale and in bigger pilot equipment. Results make possible recommend new method for the increased of ethanol concentration. Heat consumption reduced by 50% and cooling water consumption by 90 % when the non-reflux distillation was applied. Reflux flow in the column is replacing with contact mass, which consist from saline layer and seclude medium. Basis diagram of ethanol non-reflux saline distillation was established. Distillation equipment and number of plates in the column can calculate using basis diagram. Absolute ethanol can obtain with non-reflux saline distillation. Absolute ethanol use in produce of biofuel (author)

  7. Method of separate determination of high-ohmic sample resistance and contact resistance

    Directory of Open Access Journals (Sweden)

    Vadim A. Golubiatnikov

    2015-09-01

    Full Text Available A method of separate determination of two-pole sample volume resistance and contact resistance is suggested. The method is applicable to high-ohmic semiconductor samples: semi-insulating gallium arsenide, detector cadmium-zinc telluride (CZT, etc. The method is based on near-contact region illumination by monochromatic radiation of variable intensity from light emitting diodes with quantum energies exceeding the band gap of the material. It is necessary to obtain sample photo-current dependence upon light emitting diode current and to find the linear portion of this dependence. Extrapolation of this linear portion to the Y-axis gives the cut-off current. As the bias voltage is known, it is easy to calculate sample volume resistance. Then, using dark current value, one can determine the total contact resistance. The method was tested for n-type semi-insulating GaAs. The contact resistance value was shown to be approximately equal to the sample volume resistance. Thus, the influence of contacts must be taken into account when electrophysical data are analyzed.

  8. A method for sensible heat flux model parameterization based on radiometric surface temperature and environmental factors without involving the parameter KB-1

    Science.gov (United States)

    Zhuang, Qifeng; Wu, Bingfang; Yan, Nana; Zhu, Weiwei; Xing, Qiang

    2016-05-01

    Sensible heat flux is a key component of land-atmosphere interaction. In most parameterizations it is calculated with surface-air temperature differences and total aerodynamic resistance to heat transfer (Rae) that is related to the KB-1 parameter. Suitable values are hard to obtain since KB-1 is related both to canopy characteristics and environmental conditions. In this paper, a parameterize method for sensible heat flux over vegetated surfaces (maize field and grass land in the Heihe river basin of northwest China) was proposed based on the radiometric surface temperature, surface resistance (Rs) and vapor pressures (saturated and actual) at the surface and the atmosphere above the canopy. A biophysics-based surface resistance model was revised to compute surface resistance with several environmental factors. The total aerodynamic resistance to heat transfer is directly calculated by combining the biophysics-based surface resistance and vapor pressures. One merit of this method is that the calculation of KB-1 can be avoided. The method provides a new way to estimate sensible heat flux over vegetated surfaces and its performance compares well to the LAS measured sensible heat and other empirical or semi-empirical KB-1 based estimations.

  9. Silver Nanowire Transparent Conductive Films with High Uniformity Fabricated via a Dynamic Heating Method.

    Science.gov (United States)

    Jia, Yonggao; Chen, Chao; Jia, Dan; Li, Shuxin; Ji, Shulin; Ye, Changhui

    2016-04-20

    The uniformity of the sheet resistance of transparent conductive films is one of the most important quality factors for touch panel applications. However, the uniformity of silver nanowire transparent conductive films is far inferior to that of indium-doped tin oxide (ITO). Herein, we report a dynamic heating method using infrared light to achieve silver nanowire transparent conductive films with high uniformity. This method can overcome the coffee ring effect during the drying process and suppress the aggregation of silver nanowires in the film. A nonuniformity factor of the sheet resistance of the as-prepared silver nanowire transparent conductive films could be as low as 6.7% at an average sheet resistance of 35 Ω/sq and a light transmittance of 95% (at 550 nm), comparable to that of high-quality ITO film in the market. In addition, a mechanical study shows that the sheet resistance of the films has little change after 5000 bending cycles, and the film could be used in touch panels for human-machine interactive input. The highly uniform and mechanically stable silver nanowire transparent conductive films meet the requirement for many significant applications and could play a key role in the display market in a near future.

  10. Novel Coil Winding Method to Realize Pot Heated Evenly

    Institute of Scientific and Technical Information of China (English)

    Mao-Yan Wang; Hai-Long Li; Meng Zhang; Zhi-Tao Xu; Cui-Lin Zhong; Jun Xu

    2015-01-01

    To solve the problem about the inhomogeneous thermal effect of pot heated by coils along the circumference, a novel coil winding method is proposed and compared with the general winding method in the paper. First, based on the Biot-Savart law and Ampere’s rule, the magnetic induction generated by a straight current carrying conductor and a current loop is discussed, respectively. Then the novel coil winding method is developed by adjusting the location of inhomogeneous joints. The joints are periodically scattered along the circumferential direction and symmetrically designed around the central axis. Numerical results show that the quite non-uniform temperature in the base of pot at the circular direction is effectively improved by using the proposed winding method. The potential danger produced by high temperature at some region of coils plate is minimized. It is energy-efficient and safe for residential appliances.

  11. A Geographic Method for High Resolution Spatial Heat Planning

    DEFF Research Database (Denmark)

    Nielsen, Steffen

    2014-01-01

    more detailed modelling that takes the geographic placement of buildings and the differences among DH systems into account. In the present article, a method for assessing the costs of DH expansions has been developed. The method was applied in a geographic information system (GIS) model that consists...... are considering distribution costs based on the geographic properties of each area and assessing transmission costs based on an iterative process that examines expansion potentials gradually. The GIS model is only applicable to a Danish context, but the method itself can be applied to other countries....... of three parts and assesses the costs of heat production, distribution, and transmission. The model was also applied to an actual case in order to show how it can be used. The model shows many improvements in the method for the assessment of distribution costs and transmission costs. Most notable...

  12. Fast Prediction Method for Steady-State Heat Convection

    KAUST Repository

    Wáng, Yì

    2012-03-14

    A reduced model by proper orthogonal decomposition (POD) and Galerkin projection methods for steady-state heat convection is established on a nonuniform grid. It was verified by thousands of examples that the results are in good agreement with the results obtained from the finite volume method. This model can also predict the cases where model parameters far exceed the sample scope. Moreover, the calculation time needed by the model is much shorter than that needed for the finite volume method. Thus, the nonuniform POD-Galerkin projection method exhibits high accuracy, good suitability, and fast computation. It has universal significance for accurate and fast prediction. Also, the methodology can be applied to more complex modeling in chemical engineering and technology, such as reaction and turbulence. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Effect of the medium characteristics and the heating and cooling rates on the nonisothermal heat resistance of Bacillus sporothermodurans IC4 spores.

    Science.gov (United States)

    Esteban, María-Dolores; Huertas, Juan-Pablo; Fernández, Pablo S; Palop, Alfredo

    2013-05-01

    In recent years, highly thermo-resistant mesophilic spore-forming bacteria belonging to the species Bacillus sporothermodurans have caused non-sterility problems in industrial sterilization processes. The aim of this research was to evaluate the effect of the heating medium characteristics (pH and buffer/food) on the thermal inactivation of B. sporothermodurans spores when exposed to isothermal and non-isothermal heating and cooling treatments and the suitability of non-linear Weibull and Geeraaerd models to predict the survivors of these thermal treatments. Thermal treatments were carried out in pH 3, 5 and 7 McIlvaine buffer and in a courgette soup. Isothermal survival curves showed shoulders that were accurately characterized by means of both models. A clear effect of the pH of the heating medium was observed, decreasing the D120 value from pH 7 to pH 3 buffer down to one third. Differences in heat resistance were similar, regardless of the model used and were kept at all temperatures tested. The heat resistance in courgette soup was similar to that shown in pH 7 buffer. When the heat resistance values obtained under isothermal conditions were used to predict the survival in the non-isothermical experiments, the predictions estimated the experimental data quite accurately, both with Weibull and Geeraerd models. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Exploration of a new method in determining the glass transition temperature of BMGs by electrical resistivity

    Science.gov (United States)

    Guo, Jing; Zu, Fangqiu; Chen, Zhihao; Zheng, Shubin; Yuan, Yuan

    2005-07-01

    Based on a brief retrospect of the method in establishing Tg of the bulk metallic glasses (BMGs), some perplexities concerning this are pointed out. With the experimental results of Zr-Al-Ni-Cu-X (Nb,Ti) BMGs, a electrical resistivity method is proposed to determine the glass transition temperature of BMGs. With the method, we define two kinds of characteristic temperature related to the glass transition, Tg-dep and Tg-int, respectively. By comparing Tg-dep and Tg-int with Tg determined by the DSC method, we have found that, for the same alloy at the same heating rate, Tg-dep is very close to Tg-onset while Tg-int is approximate to Tg-mid. As a method to determine the glass transition temperature, the electrical resistivity method has proved to be more convenient and practical in comparison with the DSC method, especially when the DSC curve cannot show the glass transition character of BMGs. In addition, we would emphasize that when we refer to Tg, it is necessary to expatiate on the way of denoting the glass transition temperature, such as Tg-dep or Tg-int ( Tg-onset or Tg-mid), and on the heating rate, in order to avoid ambiguity.

  15. Experimentally aided development of a turbine heat transfer prediction method

    International Nuclear Information System (INIS)

    Forest, A.E.; White, A.J.; Lai, C.C.; Guo, S.M.; Oldfield, M.L.G.; Lock, G.D.

    2004-01-01

    In the design of cooled turbomachinery blading a central role is played by the computer methods used to optimise the aerodynamic and thermal performance of the turbine aerofoils. Estimates of the heat load on the turbine blading should be as accurate as possible, in order that adequate life may be obtained with the minimum cooling air requirement. Computer methods are required which are able to model transonic flows, which are a mixture of high temperature combustion gases and relatively cool air injected through holes in the aerofoil surface. These holes may be of complex geometry, devised after empirical studies of the optimum shape and the most cost effective manufacturing technology. The method used here is a further development of the heat transfer design code (HTDC), originally written by Rolls-Royce plc under subcontract to Rolls-Royce Inc for the United States Air Force. The physical principles of the modelling employed in the code are explained without extensive mathematical details. The paper describes the calibration of the code in conjunction with a series of experimental measurements on a scale model of a high-pressure nozzle guide vane at non-dimensionally correct engine conditions. The results are encouraging, although indicating that some further work is required in modelling highly accelerated pressure surface flow

  16. Effect of air confinement on thermal contact resistance in nanoscale heat transfer

    Science.gov (United States)

    Pratap, Dheeraj; Islam, Rakibul; Al-Alam, Patricia; Randrianalisoa, Jaona; Trannoy, Nathalie

    2018-03-01

    Here, we report a detailed analysis of thermal contact resistance (R c) of nano-size contact formed between a Wollaston wire thermal probe and the used samples (fused silica and titanium) as a function of air pressure (from 1 Pa to 105 Pa). Moreover, we suggest an analytical model using experimental data to extract R c. We found that for both samples, the thermal contact resistance decreases with increasing air pressure. We also showed that R c strongly depends on the thermal conductivity of materials keeping other parameters the same, such as roughness of the probe and samples, as well as the contact force. We provide a physical explanation of the R c trend with pressure and thermal conductivity of the materials: R c is ascribed to the heat transfer through solid-solid (probe-sample) contact and confined air at nanoscale cavities, due to the rough nature of the materials in contact. The contribution of confined air on heat transfer through the probe sample contact is significant at atmospheric pressure but decreases as the pressure decreases. In vacuum, only the solid-solid contact contributes to R c. In addition, theoretical calculations using the well-known acoustic and diffuse mismatch models showed a high thermal conductivity material that exhibits high heat transmission and consequently low R c, supporting our findings.

  17. Method of absorbance correction in a spectroscopic heating value sensor

    Science.gov (United States)

    Saveliev, Alexei; Jangale, Vilas Vyankatrao; Zelepouga, Sergeui; Pratapas, John

    2013-09-17

    A method and apparatus for absorbance correction in a spectroscopic heating value sensor in which a reference light intensity measurement is made on a non-absorbing reference fluid, a light intensity measurement is made on a sample fluid, and a measured light absorbance of the sample fluid is determined. A corrective light intensity measurement at a non-absorbing wavelength of the sample fluid is made on the sample fluid from which an absorbance correction factor is determined. The absorbance correction factor is then applied to the measured light absorbance of the sample fluid to arrive at a true or accurate absorbance for the sample fluid.

  18. Resistivity measurements using a direct current induction method (1963)

    International Nuclear Information System (INIS)

    Delaplace, J.; Hillairet, J.

    1964-01-01

    The conventional methods for measuring electrical resistivities necessitate the fixing of electrical contacts on the sample either mechanically or by soldering. Furthermore it is also necessary to carry,out the measurements on low cross-section samples which are not always easy to obtain. Our direct-current induction method on the other hand requires no contacts and can easily be applied to samples of large cross-section. The sample is placed in a uniform magnetic field; at the moment when the current is cut, eddy currents appear in the sample which tend to oppose the disappearance of the field. The way in which the magnetic flux decreases in the sample makes it possible to determine the resistivity of the material. This method has been applied to samples having diameters of between 1 and 30 mm in the case of metals which are good conductors. It gives a value for the local resistivity and makes it possible to detect any variation along a sample. The measurements can be carried out at all temperature from a few degrees absolute to 500 deg. C. We have used the induction method to follow the purification of beryllium by zone-melting; it is in effect possible to estimate the purity of a material by resistivity measurements. We have measured the resistivity along each bar treated by the zone-melting technique and have thus, localised the purest section. High temperature measurements have been carried out on uranium carbide and on iron-aluminium alloys. This method constitutes an interesting means of investigation the resistivity of solid materials. Its accuracy and rapidity make it particularly adapted both to fundamental research and to production control. (authors) [fr

  19. Influence of cerium, zirconium and boron on the oxidation resistance of heat-resistant steels in air

    International Nuclear Information System (INIS)

    Gala, A.; Schendler, W.

    1981-01-01

    Isothermal and cyclic oxidation experiments were carried out in air to investigate the influence of the minor elements such as Cerium, Zirkonium and Boron on the oxidation resistance of heat resistant ferritic and austenitic steels like X10Cr18, X10CrAl18 and X15CrNiSi2012. In the case of cyclicexperiments samples were exposed at constant temperatures for 100 h and then cooled to R.T. This cycle was repeated 10 times. The corrosion was determined as weight change and was continuously measured by a thermo-balance. The distribution of the alloying elements on the phase boundary scale/steel was examined by Scanning-Electron-Microscope. Addition of small amounts of Ce (0.3 wt-% max.) could reduce the oxidation rate in the case of isothermal and cyclic conditions. Zirkonium concentrations below 0.1 wt-% could have a beneficial effect, but at higher concentrations the oxidation rate increases with increasing amounts of Zr. Small Boron concentrations of 0.02 wt-% lead to catastrophic oxidation at temperatures above 1000 0 C. (orig.) [de

  20. Effect of heat curing methods on the temperature history and strength development of slab concrete for nuclear power plant structures in cold climates

    International Nuclear Information System (INIS)

    Lee, Gun Cheol; Han, Min Cheol; Baek, Dae Hyun; Koh, Kyung Taek

    2012-01-01

    The objective of this study was to experimentally investigate the effect of heat curing methods on the temperature history and strength development of slab concrete exposed to -10 degrees Celsius. The goal was to determine proper heat curing methods for the protection of nuclear power plant structures against early-age frost damage under adverse (cold) conditions. Two types of methods were studied: heat insulation alone and in combination with a heating cable. For heat curing with heat insulation alone, either sawdust or a double layer bubble sheet (2-BS) was applied. For curing with a combination of heat insulation and a heating cable, an embedded heating cable was used with either a sawdust cover, a 2-BS cover, or a quadruple layer bubble sheet (4-BS) cover. Seven different slab specimens with dimensions of 1200, 600, 200 mm and a design strength of 27 MPa were fabricated and cured at -10 degrees Celsius for 7 d. The application of sawdust and 2-BS allowed the concrete temperature to fall below 0 degrees Celsius within 40 h after exposure to -10 degrees Celsius, and then, the temperature dropped to -10 degrees Celsius and remained there for 7 d owing to insufficient thermal resistance. However, the combination of a heating cable plus sawdust or 2-BS maintained the concrete temperature around 5 degrees Celsius for 7 d. Moreover, the combination of the heating cable and 4-BS maintained the concrete temperature around 10 degrees Celsius for 7 d. This was due to the continuous heat supply from the heating cable and the prevention of heat loss by the 4-BS. For maturity development, which is an index of early-age frost damage, the application of heat insulation materials alone did not allow the concrete to meet the minimum maturity required to protect against early-age frost damage after 7 d, owing to poor thermal resistance. However, the combination of the heating cable and the heat insulating materials allowed the concrete to attain the minimum maturity level after

  1. The encapsulated nuclear heat source reactor for proliferation-resistant nuclear energy

    International Nuclear Information System (INIS)

    Brown, N.W.; Hossain, Q.; Carelli, M.D.; Conway, L.; Dzodzo, M.; Greenspan, E.; Saphier, D.

    2001-01-01

    The encapsulated nuclear heat source (ENHS) is a modular reactor that was selected by the 1999 DOE NERI program as a candidate ''Generation-IV'' reactor concept. It is a fast neutron spectrum reactor cooled by Pb-Bi using natural circulation. It is designed for passive load following, for high level of passive safety, and for 15 years without refueling. One of the unique features of the ENHS is that the fission-generated heat is transferred from the primary coolant to the secondary coolant across the reactor vessel wall by conduction-providing for an essentially sealed module that is easy to install and replace. Because the fuel is encapsulated within a heavy steel container throughout its life it provides a unique improvement to the proliferation resistance of the nuclear fuel cycle. This paper presents the innovative technology of the ENHS. (author)

  2. Laboratory methods for diagnosis and detection of drug resistant ...

    African Journals Online (AJOL)

    Data source: Published series of peer reviewed journals and manuals written on laboratory methods that are currently used for diagnosis and detection of drug resistance of Mycobacterium tuberculosis complex were reviewed using the index medicus, pubmed and medline search. Conventional bacteriological microscopy ...

  3. Cast Steels for Creep-Resistant Parts Used in Heat Treatment Plants

    Directory of Open Access Journals (Sweden)

    Drotlew A.

    2012-12-01

    Full Text Available Creep-resistant parts of heat treatment furnaces are in most cases made from high-alloyed chromium-nickel and nickel-chromium iron alloys, both cast and wrought. This paper presents the types of casting alloys used for this particular purpose, since the majority of furnace components are made by the casting process. Standards were cited which give symbols of alloy grades used in technical specifications by the domestic industry. It has been indicated that castings made currently are based on a wider spectrum of the creep-resistant alloy grades than the number of alloys covered by the standards. Alloy grades recommended by the technical literature for individual parts of the furnace equipment were given. The recommendations reflect both the type of the technological process used and the technical tasks performed by individual parts of the furnace equipment. Comments were also made on the role of individual alloying elements in shaping the performance properties of castings.

  4. Cast Steels for Creep-resistant Parts Used in Heat Treatment Plants

    Directory of Open Access Journals (Sweden)

    A. Drotlew

    2012-12-01

    Full Text Available Creep-resistant parts of heat treatment furnaces are in most cases made from high-alloyed chromium-nickel and nickel-chromium ironalloys, both cast and wrought. This paper presents the types of casting alloys used for this particular purpose, since the majority of furnace components are made by the casting process. Standards were cited which give symbols of alloy grades used in technical specifications by the domestic industry. It has been indicated that castings made currently are based on a wider spectrum of the creep-resistant alloy grades than the number of alloys covered by the standards. Alloy grades recommended by the technical literature for individual parts of the furnace equipment were given. The recommendations reflect both the type of the technological process used and the technical tasks performed by individual parts of the furnace equipment. Comments were also made on the role of individual alloying elements in shaping the performance properties of castings.

  5. Heat-affected zone liquation crack on resistance spot welded TWIP steels

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Dulal Chandra [Department of Advanced Materials Engineering, Dong-Eui University, 995 Eomgwangno, Busanjin-gu, Busan 614-714 (Korea, Republic of); Chang, InSung [Automotive Production Development Division, Hyundai Motor Company (Korea, Republic of); Park, Yeong-Do, E-mail: ypark@deu.ac.kr [Department of Advanced Materials Engineering, Dong-Eui University, 995 Eomgwangno, Busanjin-gu, Busan 614-714 (Korea, Republic of)

    2014-07-01

    In this study, the heat affected zone (HAZ) liquation crack and segregation behavior of the resistance spot welded twinning induced plasticity (TWIP) steel have been reported. Cracks appeared in the post-welded joints that originated at the partially melted zone (PMZ) and propagated from the PMZ through the heat affected zone (HAZ) to the base metal (BM). The crack length and crack opening widths were observed increasing with heat input; and the welding current was identified to be the most influencing parameter for crack formation. Cracks appeared at the PMZ when nugget diameter reached at 4.50 mm or above; and the liquation cracks were found to occur along two sides of the notch tip in the sheet direction rather than in the electrode direction. Cracks were backfilled with the liquid films which has lamellar structure and supposed to be the eutectic constituent. Co-segregation of alloy elements such as, C and Mn were detected on the liquid films by electron-probe microanalysis (EPMA) line scanning and element map which suggests that the liquid film was enrich of Mn and C. The eutectic constituent was identified by analyzing the calculated phase diagram along with thermal temperature history of finite element simulation. Preliminary experimental results showed that cracks have less/no significant effect on the static cross-tensile strength (CTS) and the tensile-shear strength (TSS). In addition, possible ways to avoid cracking were discussed. - Highlights: • The HAZ liquation crack during resistance spot welding of TWIP steel was examined. • Cracks were completely backfilled and healed with divorced eutectic secondary phase. • Co-segregation of C and Mn was detected in the cracked zone. • Heat input was the most influencing factor to initiate liquation crack. • Cracks have less/no significant effect on static tensile properties.

  6. Corrosion resistance of structural material AlMg-2 in water following heat treatment and cooling

    International Nuclear Information System (INIS)

    Maman Kartaman A; Djoko Kisworo; Dedi Hariyadi; Sigit

    2005-01-01

    Corrosion tests of structural material AlMg-2 in water were carried out using autoclave in order to study the effects of heat treatment on the corrosion resistance of the material. Prior to the tests, the samples were heat-treated at temperatures of 90, 200, 300 and 500 °C and cooled in air, sand and water. The corrosion tests were conducted in water at temperature of 150 °C for 250 hours. The results showed that AlMg-2 samples were corroded although the increase of mass gain was relatively small. Heat treatment from 90 to 500 °C in sand cooling media resulted in an increase of mass gain despite that at 300 °C the increase was less than those at 200 °C and 500 °C. For water cooling media in the temperature range of 90 to 200 °C, the mass gain increased from 0.1854 g/cm 2 to 2.1204 g/cm 2 although after 200 °C it decreased to 1.8207 g/cm 2 and 1.6779 g/cm 2 respectively. For air cooling media, the mass gain was relatively constant. Based on the experiment results, it can be concluded that heat treatment and cooling did not significantly influence the corrosion resistance of material AlMg-2. The passive film Al 2 O 3 on the surface was able to protect the inner surface from further corrosion. Water media with pH range from 4 – 9 did not cause damage to passive layer formed. (author)

  7. Heat-affected zone liquation crack on resistance spot welded TWIP steels

    International Nuclear Information System (INIS)

    Saha, Dulal Chandra; Chang, InSung; Park, Yeong-Do

    2014-01-01

    In this study, the heat affected zone (HAZ) liquation crack and segregation behavior of the resistance spot welded twinning induced plasticity (TWIP) steel have been reported. Cracks appeared in the post-welded joints that originated at the partially melted zone (PMZ) and propagated from the PMZ through the heat affected zone (HAZ) to the base metal (BM). The crack length and crack opening widths were observed increasing with heat input; and the welding current was identified to be the most influencing parameter for crack formation. Cracks appeared at the PMZ when nugget diameter reached at 4.50 mm or above; and the liquation cracks were found to occur along two sides of the notch tip in the sheet direction rather than in the electrode direction. Cracks were backfilled with the liquid films which has lamellar structure and supposed to be the eutectic constituent. Co-segregation of alloy elements such as, C and Mn were detected on the liquid films by electron-probe microanalysis (EPMA) line scanning and element map which suggests that the liquid film was enrich of Mn and C. The eutectic constituent was identified by analyzing the calculated phase diagram along with thermal temperature history of finite element simulation. Preliminary experimental results showed that cracks have less/no significant effect on the static cross-tensile strength (CTS) and the tensile-shear strength (TSS). In addition, possible ways to avoid cracking were discussed. - Highlights: • The HAZ liquation crack during resistance spot welding of TWIP steel was examined. • Cracks were completely backfilled and healed with divorced eutectic secondary phase. • Co-segregation of C and Mn was detected in the cracked zone. • Heat input was the most influencing factor to initiate liquation crack. • Cracks have less/no significant effect on static tensile properties

  8. The generalized approximation method and nonlinear heat transfer equations

    Directory of Open Access Journals (Sweden)

    Rahmat Khan

    2009-01-01

    Full Text Available Generalized approximation technique for a solution of one-dimensional steady state heat transfer problem in a slab made of a material with temperature dependent thermal conductivity, is developed. The results obtained by the generalized approximation method (GAM are compared with those studied via homotopy perturbation method (HPM. For this problem, the results obtained by the GAM are more accurate as compared to the HPM. Moreover, our (GAM generate a sequence of solutions of linear problems that converges monotonically and rapidly to a solution of the original nonlinear problem. Each approximate solution is obtained as the solution of a linear problem. We present numerical simulations to illustrate and confirm the theoretical results.

  9. Precipitation behavior in a nitride-strengthened martensitic heat resistant steel during hot deformation

    Directory of Open Access Journals (Sweden)

    Wenfeng Zhang

    2015-09-01

    Full Text Available The stress relaxation curves for three different hot deformation processes in the temperature range of 750–1000 °C were studied to develop an understanding of the precipitation behavior in a nitride-strengthened martensitic heat resistant steel (Zhang et al., Mater. Sci. Eng. A, 2015 [1]. This data article provides supporting data and detailed information on how to accurately analysis the stress relaxation data. The statistical analysis of the stress peak curves, including the number of peaks, the intensity of the peaks and the integral value of the pumps, was carried out. Meanwhile, the XRD energy spectrum data was also calculated in terms of lattice distortion.

  10. Fire and heat resistant laminating resins based on maleimido substituted aromatic cyclotriphosphazene polymer

    Science.gov (United States)

    Kumar, Devendra (Inventor); Fohlen, George M. (Inventor); Parker, John A. (Inventor)

    1987-01-01

    4-Aminophenoxy cyclotriphosphazenes are reacted with maleic anhydride to produce maleamic acids which are converted to the maleimides. The maleimides are polymerized. By selection of starting materials (e.g., hexakis amino or trisaminophenoxy trisphenoxy cyclotriphosphazenes), selection of molar proportions of reactants, use of mixtures of anhydrides and use of dianhydrides as bridging groups a variety of maleimides and polymers are produced. The polymers have high limiting oxygen indices, high char yields and other useful heat and fire resistant properties making them useful as, for example, impregnants of fabrics.

  11. REM effect on nonmetallic inclusion composition and heat resistance in an austenitic steel

    International Nuclear Information System (INIS)

    Farafonov, V.K.; Shtejnberg, M.M.; Kikhtin, M.V.; Cheremnykh, V.P.; Vojnov, V.V.

    1979-01-01

    Studies were made to elucidate the effect of rare earths (lanthanum, neodymium, praseodymium, cerium) on the composition of non-metallic inclusions and heat resistance of an austenitic chromium-nickel steel. Common sulfide and oxide inclusions are shown to be substituted by rare earth sulfide and oxide inclusions at RE metal content in the steel up to 0.1%. Further increase of RE metal content results in increasing non-metallic inclusions containing RE metals, phosphorus and non-ferrous impurities. Creep rate changes insignificantly at RE metal content up to 0.1%, and then it sharply grows with the quantity of non-metallic inclusions in the steel

  12. Microstructural evolution during creep deformation of an 11CrMoVNb ferritic heat resistant steel

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyu-Ho; Park, Dae-Bum [Korea Institute of Science and Technology, Seoul (Korea, Republic of). Materials and Devices Div.; Korea Univ., Seoul (Korea, Republic of). Dept. of Materials Science; Kwun, S.I. [Korea Univ., Seoul (Korea, Republic of). Dept. of Materials Science; Suh, Jin-Yoo; Jung, Woo-Sang [Korea Institute of Science and Technology, Seoul (Korea, Republic of). Materials and Devices Div.

    2010-07-01

    The effect of creep deformation on the microstructural development of an 11CrMoVNb ferritic heat resistant steel during high temperature creep test is investigated. Coarsening behavior of the precipitates, M{sub 23}C{sub 6} and MX, and growth behavior of martensite laths of crept specimens are carefully observed from both gage and grip parts of the specimens in order to discuss the effect of deformation. Particle coarsening and martensite lath widening are pronounced in the gage part due to the creep deformation. (orig.)

  13. Studies on neutron irradiation effects of iron alloys and nickel-base heat resistant alloys

    International Nuclear Information System (INIS)

    Watanabe, Katsutoshi

    1987-09-01

    The present paper describes the results of neutron irradiation effects on iron alloys and nickel-base heat resistant alloys. As for the iron alloys, irradiation hardening and embrittlement were investigated using internal friction measurement, electron microscopy and tensile testings. The role of alloying elements was also investigated to understand the irradiation behavior of iron alloys. The essential factors affecting irradiation hardening and embrittlement were thus clarified. On the other hand, postirradiation tensile and creep properties were measured of Hastelloy X alloy. Irradiation behavior at elevated temperatures is discussed. (author)

  14. VARIATION OF SUBSTRUCTURES OF PEARLITIC HEAT RESISTANT STEEL AFTER HIGH TEMPERATURE AGING

    Institute of Scientific and Technical Information of China (English)

    R.C.Yang; K.Chen; H.X.Feng; H.Wang

    2004-01-01

    The observations of dislocations, substructures and other microstructural details were conducted mainly by means of transmission electron microscope (TEM) and scanning electron microscope (SEM) for 12Cr1Mo V pearlitic heat-resistant steel. It is shown that during the high temperature long-term aging, the disordered and jumbled phasetransformed dislocations caused by normalized cooling are recovered and rearranged into cell substructures, and then the dislocation density is reduced gradually. Finally a low density linear dislocation configuration and a stabler dislocation network are formed and ferritic grains grow considerably.

  15. Transparent Heat-Resistant PMMA Copolymers for Packing Light-Emitting Diode Materials

    Directory of Open Access Journals (Sweden)

    Shu-Ling Yeh

    2015-07-01

    Full Text Available Transparent and heat-resistant poly(methyl methacrylate copolymers were synthesized by bulk polymerizing methyl methacrylate (MMA, isobornyl methacrylate (IBMA, and methacrylamide (MAA monomers. Copolymerization was performed using a chain transfer agent to investigate the molecular weight changes of these copolymers, which exhibited advantages including a low molecular weight distribution, excellent optical properties, high transparency, high glass transition temperature, low moisture absorption, and pellets that can be readily mass produced by using extrusion or jet injection for packing light-emitting diode materials.

  16. Standard test method for galling resistance of material couples

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method covers a laboratory test that ranks the galling resistance of material couples using a quantitative measure. Bare metals, alloys, nonmetallic materials, coatings, and surface modified materials may be evaluated by this test method. 1.2 This test method is not designed for evaluating the galling resistance of material couples sliding under lubricated conditions, because galling usually will not occur under lubricated sliding conditions using this test method. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  17. Influence of mutations in some structural genes of heat-shock proteins on radiation resistance of Escherichia coli

    International Nuclear Information System (INIS)

    Verbenko, V.N.; Kuznetsova, L.V.; Bikineeva, E.G.; Kalinin, V.L.

    1992-01-01

    Lethal effects of γ-irradiation were studied in Escherichia coli strains with normal repair genotype and in radiation-resistant Gam r strains, both carrying additional mutations in the structural genes dnaK, grpE, groES or groEL. The null mutation ΔdnaK52::Cm r enhanced radiation sensitivity of wild-type cells and abolished the effect of heat induced rediation-resistance (ETIRR) and elevated radiation resistance of the Gam r strains

  18. A portable borehole temperature logging system using the four-wire resistance method

    Science.gov (United States)

    Erkan, Kamil; Akkoyunlu, Bülent; Balkan, Elif; Tayanç, Mete

    2017-12-01

    High-quality temperature-depth information from boreholes with a depth of 100 m or more is used in geothermal studies and in studies of climate change. Electrical wireline tools with thermistor sensors are capable of measuring borehole temperatures with millikelvin resolution. The use of a surface readout mode allows analysis of the thermally conductive state of a borehole, which is especially important for climatic and regional heat flow studies. In this study we describe the design of a portable temperature logging tool that uses the four-wire resistance measurement method. The four-wire method enables the elimination of cable resistance effects, thus allowing millikelvin resolution of temperature data at depth. A preliminary two-wire model of the system is also described. The portability of the tool enables one to collect data from boreholes down to 300 m, even in locations with limited accessibility.

  19. Heat Transfer Modeling of an Annular On-Line Spray Water Cooling Process for Electric-Resistance-Welded Steel Pipe.

    Science.gov (United States)

    Chen, Zejun; Han, Huiquan; Ren, Wei; Huang, Guangjie

    2015-01-01

    On-line spray water cooling (OSWC) of electric-resistance-welded (ERW) steel pipes can replace the conventional off-line heat treatment process and become an important and critical procedure. The OSWC process improves production efficiency, decreases costs, and enhances the mechanical properties of ERW steel pipe, especially the impact properties of the weld joint. In this paper, an annular OSWC process is investigated based on an experimental simulation platform that can obtain precise real-time measurements of the temperature of the pipe, the water pressure and flux, etc. The effects of the modes of annular spray water cooling and related cooling parameters on the mechanical properties of the pipe are investigated. The temperature evolutions of the inner and outer walls of the pipe are measured during the spray water cooling process, and the uniformity of mechanical properties along the circumferential and longitudinal directions is investigated. A heat transfer coefficient model of spray water cooling is developed based on measured temperature data in conjunction with simulation using the finite element method. Industrial tests prove the validity of the heat transfer model of a steel pipe undergoing spray water cooling. The research results can provide a basis for the industrial application of the OSWC process in the production of ERW steel pipes.

  20. Heat Transfer Modeling of an Annular On-Line Spray Water Cooling Process for Electric-Resistance-Welded Steel Pipe

    Science.gov (United States)

    Chen, Zejun; Han, Huiquan; Ren, Wei; Huang, Guangjie

    2015-01-01

    On-line spray water cooling (OSWC) of electric-resistance-welded (ERW) steel pipes can replace the conventional off-line heat treatment process and become an important and critical procedure. The OSWC process improves production efficiency, decreases costs, and enhances the mechanical properties of ERW steel pipe, especially the impact properties of the weld joint. In this paper, an annular OSWC process is investigated based on an experimental simulation platform that can obtain precise real-time measurements of the temperature of the pipe, the water pressure and flux, etc. The effects of the modes of annular spray water cooling and related cooling parameters on the mechanical properties of the pipe are investigated. The temperature evolutions of the inner and outer walls of the pipe are measured during the spray water cooling process, and the uniformity of mechanical properties along the circumferential and longitudinal directions is investigated. A heat transfer coefficient model of spray water cooling is developed based on measured temperature data in conjunction with simulation using the finite element method. Industrial tests prove the validity of the heat transfer model of a steel pipe undergoing spray water cooling. The research results can provide a basis for the industrial application of the OSWC process in the production of ERW steel pipes. PMID:26201073

  1. Influence of temperature and heat treatment on crack resistance of ceramic tungsten

    International Nuclear Information System (INIS)

    Uskov, E.I.; Babak, A.V.; Bega, N.D.

    1983-01-01

    The effect of testing temperature in the range from 20 to 2000 deg C, and recrystallization annealing at 2200 deg C on crack resistance of ceramic tungsten in vacuum, is investigated. The extension diagrams thus obtained have been treated in accordance with the standard technique. The value of the critical crack loading and the stress intensity coefficient have been determined. Structural changes have been controlled with X-ray structural methods. Crack resistance of tungsten increases in the test temperature range from 20 deg C to Tsub(x) which is connected with the increase of mobility of screw components of dislocation loops. At the temperature more than Tsub(x) the plasticity growth of ceramic tungsten takes place simultaneously with grain boundary embrittlement. Recrystallization annealing at 2200 deg C creates the structure resistant to temperature effect; crack resistance being minimum

  2. Transient heat stress compromises the resistance of wheat (Poales: Poaceae) seedlings to Hessian fly (Diptera: Cecidomyiidae) infestation.

    Science.gov (United States)

    Currie, Yaleaka; Moch, John; Underwood, Joshua; Kharabsheh, Hamzah; Quesenberry, Amy; Miyagi, Risa; Thomas, Carolyn; Boney, Melanie; Woods, Samantha; Chen, Ming-Shun; Zhu, Lieceng

    2014-02-01

    Heat stress exerts a profound impact on the resistance of plants to parasites. In this research, we investigated the impact of an acute transient heat stress on the resistance of the wheat line 'Molly,' which contains the R gene H13, to an avirulent Hessian fly (Mayetiola destructor (Say)) population. We found that a significant portion of Molly seedlings stressed at 40 degrees C for 6 h during or after the initial Hessian fly larval attack became susceptible to otherwise avirulent insects, whereas unstressed control plants remained 100% resistant. Specifically, 77.8, 73.3, 83.3, and 46.7% of plants heat stressed at 0, 6,12, and 24 h, respectively, after the initial larval attack became susceptible. Biochemical analysis revealed that heat stress caused a transient decrease in 12-oxo-phytodienoic acid, but an increase in salicylic acid accumulation in Molly plants. The change in phytohormones after heat stress and Hessian fly infestation was not observed in 'Newton,' a near-isogenic but Hessian fly susceptible wheat line. Instead, heat stress caused a relatively prolonged reduction in palmitoleic acid. The role of phytohormones in heat-induced loss of wheat resistance was discussed.

  3. A novel method of evaluation of three heat-moisture exchangers in six different ventilator settings

    NARCIS (Netherlands)

    Unal, N.; Kanhai, J. K.; Buijk, S. L.; Pompe, J. C.; Holland, W. P.; Gültuna, I.; Ince, C.; Saygin, B.; Bruining, H. A.

    1998-01-01

    The purpose of this study was to assess and compare the humidification, heating, and resistance properties of three commercially available heat-moisture exchangers (HMEs). To mimic clinical conditions, a previously validated, new, realistic experimental set-up and measurement protocol was used.

  4. Factors affecting gas migration and contaminant redistribution in heterogeneous porous media subject to electrical resistance heating.

    Science.gov (United States)

    Munholland, Jonah L; Mumford, Kevin G; Kueper, Bernard H

    2016-01-01

    A series of intermediate-scale laboratory experiments were completed in a two-dimensional flow cell to investigate gas production and migration during the application of electrical resistance heating (ERH) for the removal of dense non-aqueous phase liquids (DNAPLs). Experiments consisted of heating water in homogeneous silica sand and heating 270 mL of trichloroethene (TCE) and chloroform (CF) DNAPL pools in heterogeneous silica sands, both under flowing groundwater conditions. Spatial and temporal distributions of temperature were measured using thermocouples and observations of gas production and migration were collected using front-face image capture throughout the experiments. Post-treatment soil samples were collected and analyzed to assess DNAPL removal. Results of experiments performed in homogeneous sand subject to different groundwater flow rates showed that high groundwater velocities can limit subsurface heating rates. In the DNAPL pool experiments, temperatures increased to achieve DNAPL-water co-boiling, creating estimated gas volumes of 131 and 114 L that originated from the TCE and CF pools, respectively. Produced gas migrated vertically, entered a coarse sand lens and subsequently migrated laterally beneath an overlying capillary barrier to outside the heated treatment zone where 31-56% of the original DNAPL condensed back into a DNAPL phase. These findings demonstrate that layered heterogeneity can potentially facilitate the transport of contaminants outside the treatment zone by mobilization and condensation of gas phases during ERH applications. This underscores the need for vapor phase recovery and/or control mechanisms below the water table during application of ERH in heterogeneous porous media during the co-boiling stage, which occurs prior to reaching the boiling point of water. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Study of the structure and development of the set of reference materials of composition and structure of heat resisting nickel and intermetallic alloys

    Directory of Open Access Journals (Sweden)

    E. B. Chabina

    2016-01-01

    Full Text Available Relevance of research: There are two sizes (several microns and nanodimensional of strengthening j'-phase in single-crystal heat resisting nickel and intermetallic alloys, used for making blades of modern gas turbine engines (GTD. For in-depth study of structural and phase condition of such alloys not only qualitative description of created structure is necessary, but quantitative analysis of alloy components geometrical characteristics. Purpose of the work: Development of reference material sets of heat resisting nickel and intermetallic alloy composition and structure. Research methods: To address the measurement problem of control of structural and geometrical characteristics of single-crystal heat resisting and intermetallic alloys by analytical microscopy and X-ray diffraction analysis the research was carried out using certified measurement techniques on facilities, entered in the Register of Measurement Means of the Russian Federation. The research was carried out on microsections, foils and plates, cut in the plane {100}. Results: It is established that key parameters, defining the properties of these alloys are particle size of strengthening j' -phase, the layer thickness of j-phase between them and parameters of phases lattice. Metrological requirements for reference materials of composition and structure of heat resisting nickel and intermetallic alloys are formulated. The necessary and sufficient reference material set providing the possibility to determine the composition and structure parameters of single-crystal heat resisting nickel and intermetallic alloys is defined. The developed RM sets are certified as in-plant reference materials. Conclusion: The reference materials can be used for graduation of spectral equipment when conducting element analysis of specified class alloys; for calibration of means of measuring alloy structure parameters; for measurement of alloys phases lattice parameters; for structure reference pictures

  6. Method of calculating heat transfer in furnaces of small power

    Directory of Open Access Journals (Sweden)

    Khavanov Pavel

    2016-01-01

    Full Text Available This publication presents the experiences and results of generalization criterion equation of importance in the analysis of the processes of heat transfer and thermal calculations of low-power heat generators cooled combustion chambers. With generalizing depending estimated contribution of radiation and convective heat transfer component in the complex for the combustion chambers of small capacity boilers. Determined qualitative and quantitative dependence of the integrated radiative-convective heat transfer from the main factors working combustion chambers of small volume.

  7. Quantitative thermography and methods for in-situ determination of heat losses from district heating networks

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, B. [ed.

    1996-11-01

    The course and seminar summarizing application of infrared thermography in district heating systems control gathered Danish specialists with 5 contributions on the subject. Maintenance of the heat distribution pipelines and thermographic inspection of the systems are essential in order to avoid heat losses. (EG)

  8. Long-term behaviour of heat-resistant steels and high-temperature materials

    International Nuclear Information System (INIS)

    1987-01-01

    This book contains 10 lectures with the following subjects: On the effect of thermal pretreatment on the structure and creep behaviour of the alloy 800 H (V. Guttmann, J. Timm); Material properties of heat resistant ferritic and austenitic steels after cold forming (W. Bendick, H. Weber); Investigations for judging the working behaviour of components made of alloy 800 and alloy 617 under creep stress (H.J. Penkalla, F. Schubert); Creep behaviour of gas turbine materials in hot gas (K.H. Kloos et al.); Effect of small cold forming on the creep beahviour of gas turbine blades made of Nimonic 90 (K.H. Keienburg et al.); Investigations on creep fatigue alternating load strength of nickel alloys (G. Raule); Change of structure, creep fatigue behaviour and life of X20 Cr Mo V 12 1 (by G. Eggeler et al.); Investigations on thermal fatigue behaviour (K.H. Mayer et al.); Creep behaviour of similar welds of the steels 13 Cr Mo 4 4, 14 MoV 6 3, 10 Cr Mo 910 and GS-17 Cr Mo V 5 11 (K. Niel et al.); Determining the creep crack behaviour of heat resistant steels with samples of different geometry (K. Maile, R. Tscheuschner). (orig.,/MM) [de

  9. Development of heat resistant geopolymer-based materials from red mud and rice husk ash

    Science.gov (United States)

    Thang, Nguyen Hoc; Nhung, Le Thuy; Quyen, Pham Vo Thi Ha; Phong, Dang Thanh; Khe, Dao Thanh; Van Phuc, Nguyen

    2018-04-01

    Geopolymer is an inorganic polymer composite developed by Joseph Davidovits in 1970s. Such material has potentials to replace Ordinary Portland Cement (OPC)-based materials in the future because of its lower energy consumption, minimal CO2 emissions and lower production cost as it utilizes industrial waste resources. Hence, geopolymerization and the process to produce geopolymers for various applications like building materials can be considered as green industry. Moreover, in this study, red mud and rice husk ash were used as raw materials for geopolymeric production, which are aluminum industrial and agricultural wastes that need to be managed to reduce their negative impact to the environment. The red mud and rice husk ash were mixed with sodium silicate (water glass) solution to form geopolymer paste. The geopolymer paste was filled into 5-cm cube molds according to ASTM C109/C109M 99, and then cured at room temperature for 28 days. These products were then tested for compressive strength and volumetric weight. Results indicated that the material can be considered lightweight with a compressive strength at 28 days that are in the range of 6.8 to 15.5 MPa. Moreover, the geopolymer specimens were also tested for heat resistance at a temperature of 1000oC for 2 hours. Results suggest high heat resistance with an increase of compressive strength from 262% to 417% after exposed at high temperature.

  10. Analysis Of Post-Wet-Chemistry Heat Treatment Effects On Nb SRF Surface Resistance

    International Nuclear Information System (INIS)

    Dhakal, Pashupati; Ciovati, Gianluigi; Kneisel, Peter K.; Myneni, Ganapati Rao

    2014-01-01

    Most of the current research in superconducting radio frequency (SRF) cavities is focused on ways to reduce the construction and operating cost of SRF-based accelerators as well as on the development of new or improved cavity processing techniques. The increase in quality factors is the result of the reduction of the surface resistance of the materials. A recent test on a 1.5 GHz single cell cavity made from ingot niobium of medium purity and heat treated at 1400 °C in a ultra-high vacuum induction furnace resulted in a residual resistance of ∼ 1nΩ and a quality factor at 2.0 K increasing with field up to ∼ 5A-10 10 at a peak magnetic field of 90 mT. In this contribution, we present some results on the investigation of the origin of the extended Q 0 -increase, obtained by multiple HF rinses, oxypolishing and heat treatment of A ''all NbA'' cavities

  11. Prediction of long-term precipitate evolution in austenitic heat-resistant steels

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Jae-Hyeok; Jung, Woo-Sang; Cho, Young Whan [Korea Institute of Science and Technology, Seoul (Korea, Republic of). Materials/Devices Div.; Kozeschnik, Ernst [Vienna Univ. of Technology (Austria). Inst. of Materials Science and Technology

    2010-07-01

    Numerical prediction of the long-term precipitate evolution in five different austenitic heat-resistant stainless steels, NF709, Super304H, Sanicro25, CF8C-PLUS and HTUPS has been carried out. MX and M{sub 23}C{sub 6} are predicted to remain as major precipitates during long-term aging in these steels. The addition of 3 wt% Cu produces very fine Cu-rich precipitates during aging in Super304H and Sanicro25. It is found that the amount of Z phase start to increase remarkably between 1,000 and 10,000 hours of aging at the expense of MX precipitates in the steels containing a high nitrogen content. However, the growth rate of Z phase is relatively slow and its average size reaches at most a few tens of nanometers after 100,000 hours of aging at 700 C, compared with 9-12% Cr ferritic/martensitic heat-resistant steels. The predicted precipitation sequence and precipitate size during aging are in general agreement with experimental observations. (orig.)

  12. Methods for microwave heat treatment of manufactured components

    Science.gov (United States)

    Ripley, Edward B.

    2010-08-03

    An apparatus for heat treating manufactured components using microwave energy and microwave susceptor material. Heat treating medium such as eutectic salts may be employed. A fluidized bed introduces process gases which may include carburizing or nitriding gases. The process may be operated in a batch mode or continuous process mode. A microwave heating probe may be used to restart a frozen eutectic salt bath.

  13. Methods for characterizing convective cryoprobe heat transfer in ultrasound gel phantoms.

    Science.gov (United States)

    Etheridge, Michael L; Choi, Jeunghwan; Ramadhyani, Satish; Bischof, John C

    2013-02-01

    While cryosurgery has proven capable in treating of a variety of conditions, it has met with some resistance among physicians, in part due to shortcomings in the ability to predict treatment outcomes. Here we attempt to address several key issues related to predictive modeling by demonstrating methods for accurately characterizing heat transfer from cryoprobes, report temperature dependent thermal properties for ultrasound gel (a convenient tissue phantom) down to cryogenic temperatures, and demonstrate the ability of convective exchange heat transfer boundary conditions to accurately describe freezing in the case of single and multiple interacting cryoprobe(s). Temperature dependent changes in the specific heat and thermal conductivity for ultrasound gel are reported down to -150 °C for the first time here and these data were used to accurately describe freezing in ultrasound gel in subsequent modeling. Freezing around a single and two interacting cryoprobe(s) was characterized in the ultrasound gel phantom by mapping the temperature in and around the "iceball" with carefully placed thermocouple arrays. These experimental data were fit with finite-element modeling in COMSOL Multiphysics, which was used to investigate the sensitivity and effectiveness of convective boundary conditions in describing heat transfer from the cryoprobes. Heat transfer at the probe tip was described in terms of a convective coefficient and the cryogen temperature. While model accuracy depended strongly on spatial (i.e., along the exchange surface) variation in the convective coefficient, it was much less sensitive to spatial and transient variations in the cryogen temperature parameter. The optimized fit, convective exchange conditions for the single-probe case also provided close agreement with the experimental data for the case of two interacting cryoprobes, suggesting that this basic characterization and modeling approach can be extended to accurately describe more complicated

  14. Modelling of complex heat transfer systems by the coupling method

    Energy Technology Data Exchange (ETDEWEB)

    Bacot, P.; Bonfils, R.; Neveu, A.; Ribuot, J. (Centre d' Energetique de l' Ecole des Mines de Paris, 75 (France))

    1985-04-01

    The coupling method proposed here is designed to reduce the size of matrices which appear in the modelling of heat transfer systems. It consists in isolating the elements that can be modelled separately, and among the input variables of a component, identifying those which will couple it to another component. By grouping these types of variable, one can thus identify a so-called coupling matrix of reduced size, and relate it to the overall system. This matrix allows the calculation of the coupling temperatures as a function of external stresses, and of the state of the overall system at the previous instant. The internal temperatures of the components are determined from for previous ones. Two examples of applications are presented, one concerning a dwelling unit, and the second a solar water heater.

  15. Improved dental implant drill durability and performance using heat and wear resistant protective coatings.

    Science.gov (United States)

    Er, Nilay; Alkan, Alper; İlday, Serim; Bengu, Erman

    2018-03-02

    Dental implant drilling procedure is an essential step for implant surgery and frictional heat appeared in bone during drilling is a key factor affecting the success of an implant. The aim of this study is to increase the dental implant drill lifetime and performance using heat- and wear-resistant protective coatings hence to decrease the alveolar bone temperature caused by the dental implant drilling procedure. Commercially obtained stainless steel drills were coated with titanium aluminum nitride, diamond-like carbon, titanium boron nitride, and boron nitride coatings via magnetron-sputter deposition. Drilling procedure was performed on a bovine femoral cortical bone under the conditions mimicking clinical practice, where the tests were performed both under water-assisted cooling and under the conditions without any cooling was applied. Coated drill performances and durabilities were compared to that of three commonly used commercial drills which surfaces are made from namely; zirconia, black diamond and stainless steel. Protective coatings with boron nitride, titanium boron nitride and diamond-like carbon have significantly improved drill performance and durability. Especially boron nitride-coated drills have performed within safe bone temperature limits for 50 drillings even without any cooling is applied. Titanium aluminium nitride coated drills did not show any improvement over commercially obtained stainless steel drills. Surface modification using heat and wear resistant coatings is an easy and highly effective way to improve implant drill performance and durability, which can reflect positively on surgical procedure and healing period afterwards. The noteworthy success of different types of coatings is novel and likely to be applicable to various other medical systems.

  16. Observation of trapped gas during electrical resistance heating of trichloroethylene under passive venting conditions

    Science.gov (United States)

    Martin, E. J.; Kueper, B. H.

    2011-11-01

    A two-dimensional experiment employing a heterogeneous sand pack incorporating two pools of trichloroethylene (TCE) was performed to assess the efficacy of electrical resistance heating (ERH) under passive venting conditions. Temperature monitoring displayed the existence of a TCE-water co-boiling plateau at 73.4 °C, followed by continued heating to 100 °C. A 5 cm thick gas accumulation formed beneath a fine-grained capillary barrier during and after co-boiling. The capillary barrier did not desaturate during the course of the experiment; the only pathway for gas escape being through perforated wells traversing the barrier. The thickness of the accumulation was dictated by the entry pressure of the perforated well. The theoretical maximum TCE soil concentration within the region of gas accumulation, following gas collapse, was estimated to be 888 mg/kg. Post-heating soil sampling revealed TCE concentrations in this region ranging from 27 mg/kg to 96.7 mg/kg, indicating removal of aqueous and gas phase TCE following co-boiling as a result of subsequent boiling of water. The equilibrium concentrations of TCE in water corresponding to the range of post-treatment concentrations in soil (6.11 mg/kg to 136 mg/kg) are calculated to range from 19.8 mg/l to 440 mg/l. The results of this experiment illustrate the importance of providing gas phase venting during the application of ERH in heterogeneous porous media.

  17. pH and Heat Resistance of the Major Celery Allergen Api g 1.

    Science.gov (United States)

    Rib-Schmidt, Carina; Riedl, Philipp; Meisinger, Veronika; Schwaben, Luisa; Schulenborg, Thomas; Reuter, Andreas; Schiller, Dirk; Seutter von Loetzen, Christian; Rösch, Paul

    2018-05-25

    The major celery allergen Api g 1 is a member of the pathogenesis-related 10 class protein family. Here we aimed to investigate the impact of heat and pH on the native protein conformation required for Immunoglobulin E (IgE) recognition. Spectroscopic methods, MS and IgE binding analyses were used to study the effects of pH and thermal treatment on Api g 1.0101. Heat processing results in a loss of the native protein fold via denaturation, oligomerisation and precipitation along with a subsequent reduction of IgE recognition. The induced effects and timescales are strongly pH depended. While Api g 1 refolds partially into an IgE-binding conformation at physiological pH, acidic pH treatment leads to the formation of structurally heat resistant, IgE-reactive oligomers. Thermal processing in the presence of a celery matrix or at pH conditions close to the isoelectric point (pI = 4.63) of Api g 1.0101 results in almost instant precipitation. Our data demonstrate that Api g 1.0101 is not intrinsically susceptible to heat treatment in vitro. However, the pH and the celery matrix strongly influence the stability of Api g 1.0101 and might be the main reasons for the observed temperature lability of this important food allergen. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  18. Device and method for measuring the coefficient of performance of a heat pump

    Science.gov (United States)

    Brantley, V.R.; Miller, D.R.

    1982-05-18

    A method and instrument is provided which allows quick and accurate measurement of the coefficient of performance of an installed electrically powered heat pump including auxiliary resistane heaters. Temperature-sensitive resistors are placed in the return and supply air ducts to measure the temperature increase of the air across the refrigerant and resistive-heating elements of the system. The voltages across the resistors which are directly proportional to the respective duct tempertures are applied to the inputs of a differential amplifier so that its output voltage is proportional to the temperature difference across the unit. A voltage-to-frequency converter connected to the output of the differential amplifier converts the voltage signal to a proportional-frequency signal. A digital watt meter is used to measure the power to the unit and produces a signal having a frequency proportional to the input power. A digital logic circuit ratios the temperature difference signal and the electric power input signal in a unique manner to produce a single number which is the coefficient of performance of the unit over the test interval. The digital logic and an in-situ calibration procedure enables the instrument to make these measurements in such a way that the ratio of heat flow/power input is obtained without computations. No specialized knowledge of thermodynamics or electrons is required to operate the instrument.

  19. Computational methods for structural load and resistance modeling

    Science.gov (United States)

    Thacker, B. H.; Millwater, H. R.; Harren, S. V.

    1991-01-01

    An automated capability for computing structural reliability considering uncertainties in both load and resistance variables is presented. The computations are carried out using an automated Advanced Mean Value iteration algorithm (AMV +) with performance functions involving load and resistance variables obtained by both explicit and implicit methods. A complete description of the procedures used is given as well as several illustrative examples, verified by Monte Carlo Analysis. In particular, the computational methods described in the paper are shown to be quite accurate and efficient for a material nonlinear structure considering material damage as a function of several primitive random variables. The results show clearly the effectiveness of the algorithms for computing the reliability of large-scale structural systems with a maximum number of resolutions.

  20. Method of making sulfur-resistant composite metal membranes

    Science.gov (United States)

    Way, J Douglas [Boulder, CO; Lusk, Mark [Golden, CO; Thoen, Paul [Littleton, CO

    2012-01-24

    The invention provides thin, hydrogen-permeable, sulfur-resistant membranes formed from palladium or palladium-alloy coatings on porous, ceramic or metal supports. Also disclosed are methods of making these membranes via sequential electroless plating techniques, wherein the method of making the membrane includes decomposing any organic ligands present on the substrate, reducing the palladium crystallites on the substrate to reduced palladium crystallites, depositing a film of palladium metal on the substrate and then depositing a second, gold film on the palladium film. These two metal films are then annealed at a temperature between about 200.degree. C. and about 1200.degree. C. to form a sulfur-resistant, composite PdAu alloy membrane.

  1. Severely Heat Injured Survivors of E. coli O157:H7 ATCC 43888 Display Variable and Heterogeneous Stress Resistance Behavior

    Science.gov (United States)

    Gayán, Elisa; Govers, Sander K.; Michiels, Chris W.; Aertsen, Abram

    2016-01-01

    Although minimal food processing strategies aim to eliminate foodborne pathogens and spoilage microorganisms through a combination of mild preservation techniques, little is actually known on the resistance behavior of the small fraction of microorganisms surviving an inimical treatment. In this study, the conduct of severely heat stressed survivors of E. coli O157:H7 ATCC 43888, as an indicator for the low infectious dose foodborne enterohemorrhagic strains, was examined throughout their resuscitation and outgrowth. Despite the fact that these survivors were initially sublethally injured, they were only marginally more sensitive to a subsequent heat treatment and actually much more resistant to a subsequent high hydrostatic pressure (HHP) shock in comparison with unstressed control cells. Throughout further resuscitation, however, their initial HHP resistance rapidly faded out, while their heat resistance increased and surpassed the initial heat resistance of unstressed control cells. Results also indicated that the population eventually emerging from the severely heat stressed survivors heterogeneously consisted of both growing and non-growing cells. Together, these observations provide deeper insights into the particular behavior and heterogeneity of stressed foodborne pathogens in the context of food preservation. PMID:27917163

  2. Severely heat injured survivors of E. coli O157:H7 ATCC 43888 display variable and heterogeneous stress resistance behavior

    Directory of Open Access Journals (Sweden)

    Elisa Gayán

    2016-11-01

    Full Text Available Although minimal food processing strategies aim to eliminate foodborne pathogens and spoilage microorganisms through a combination of mild preservation techniques, little is actually known on the resistance behavior of the small fraction of microorganisms surviving an inimical treatment. In this study, the conduct of severely heat stressed survivors of E. coli O157:H7 ATCC 43888, as an indicator for the low infectious dose foodborne enterohaemorrhagic strains, was examined throughout their resuscitation and outgrowth. Despite the fact that these survivors were initially sublethally injured, they were only marginally more sensitive to a subsequent heat treatment and actually much more resistant to a subsequent high hydrostatic pressure (HHP shock in comparison with unstressed control cells. Throughout further resuscitation, however, their initial HHP resistance rapidly faded out, while their heat resistance increased and surpassed the initial heat resistance of unstressed control cells. Results also indicated that the population eventually emerging from the severely heat stressed survivors heterogeneously consisted of both growing and non-growing persister-like cells. Together, these observations provide deeper insights into the particular behavior and heterogeneity of stressed foodborne pathogens in the context of food preservation.

  3. Variation in resistance of natural isolates of Staphylococcus aureus to heat, pulsed electric field and ultrasound under pressure.

    Science.gov (United States)

    Rodríguez-Calleja, J M; Cebrián, G; Condón, S; Mañas, P

    2006-05-01

    To study and compare the resistance of 15 Staphylococcus aureus isolates to heat, pulsed electric field (PEF) and ultrasound (UW) under pressure (manosonication, MS). Survival curves to heat (58 degrees C), to PEF (22 kV cm(-1), 2 micros square wave pulses) and to UW under pressure (117 microm, 20 kHz, 200 kPa) were obtained and inactivation parameters (decimal reduction times for heat and UW under pressure, and b-values for PEF) were calculated. A wide resistance variation to heat treatment, but not to PEF and MS, was observed amongst the 15 strains. There was no relationship between the resistances to the three physical agents studied. Staphylococcus aureus was relatively resistant to MS but sensitive to PEF. Heat resistance varied with strain and was positively correlated to carotenoid pigment content. Results would help in defining safe food preservation processes. Care should be taken to choose the most adequate strain of S. aureus to model food preservation processing.

  4. Sterol biosynthesis is required for heat resistance but not extracellular survival in leishmania.

    Directory of Open Access Journals (Sweden)

    Wei Xu

    2014-10-01

    Full Text Available Sterol biosynthesis is a crucial pathway in eukaryotes leading to the production of cholesterol in animals and various C24-alkyl sterols (ergostane-based sterols in fungi, plants, and trypanosomatid protozoa. Sterols are important membrane components and precursors for the synthesis of powerful bioactive molecules, including steroid hormones in mammals. Their functions in pathogenic protozoa are not well characterized, which limits the development of sterol synthesis inhibitors as drugs. Here we investigated the role of sterol C14α-demethylase (C14DM in Leishmania parasites. C14DM is a cytochrome P450 enzyme and the primary target of azole drugs. In Leishmania, genetic or chemical inactivation of C14DM led to a complete loss of ergostane-based sterols and accumulation of 14-methylated sterols. Despite the drastic change in lipid composition, C14DM-null mutants (c14dm(- were surprisingly viable and replicative in culture. They did exhibit remarkable defects including increased membrane fluidity, failure to maintain detergent resistant membrane fraction, and hypersensitivity to heat stress. These c14dm(- mutants showed severely reduced virulence in mice but were highly resistant to itraconazole and amphotericin B, two drugs targeting sterol synthesis. Our findings suggest that the accumulation of toxic sterol intermediates in c14dm(- causes strong membrane perturbation and significant vulnerability to stress. The new knowledge may help improve the efficacy of current drugs against pathogenic protozoa by exploiting the fitness loss associated with drug resistance.

  5. Sterol biosynthesis is required for heat resistance but not extracellular survival in leishmania.

    Science.gov (United States)

    Xu, Wei; Hsu, Fong-Fu; Baykal, Eda; Huang, Juyang; Zhang, Kai

    2014-10-01

    Sterol biosynthesis is a crucial pathway in eukaryotes leading to the production of cholesterol in animals and various C24-alkyl sterols (ergostane-based sterols) in fungi, plants, and trypanosomatid protozoa. Sterols are important membrane components and precursors for the synthesis of powerful bioactive molecules, including steroid hormones in mammals. Their functions in pathogenic protozoa are not well characterized, which limits the development of sterol synthesis inhibitors as drugs. Here we investigated the role of sterol C14α-demethylase (C14DM) in Leishmania parasites. C14DM is a cytochrome P450 enzyme and the primary target of azole drugs. In Leishmania, genetic or chemical inactivation of C14DM led to a complete loss of ergostane-based sterols and accumulation of 14-methylated sterols. Despite the drastic change in lipid composition, C14DM-null mutants (c14dm(-)) were surprisingly viable and replicative in culture. They did exhibit remarkable defects including increased membrane fluidity, failure to maintain detergent resistant membrane fraction, and hypersensitivity to heat stress. These c14dm(-) mutants showed severely reduced virulence in mice but were highly resistant to itraconazole and amphotericin B, two drugs targeting sterol synthesis. Our findings suggest that the accumulation of toxic sterol intermediates in c14dm(-) causes strong membrane perturbation and significant vulnerability to stress. The new knowledge may help improve the efficacy of current drugs against pathogenic protozoa by exploiting the fitness loss associated with drug resistance.

  6. Heat control in HVDC resistive divider by PID and NN controllers

    International Nuclear Information System (INIS)

    Yilmaz, S.; Dincer, H.; Eksin, I.; Kalenderli, O.

    2007-01-01

    In this study, a control system is presented that is devised to increase measurement precisions within a prototype high voltage DC resistive divider (HVDC-RD). Since one of the major sources of measurement errors in such devices is the self heating effect, a system controlling the temperature within the high voltage DC resistive divider is devised so that suitable and stable temperature conditions are maintained that, in return, will decrease the measurement errors. The resistive divider system is cooled by oil, and PID and neural network (NN) controllers try to keep the temperature within the prescribed limits. The system to be controlled exhibits a nonlinear character, and therefore, a control approach based on NN controllers is proposed. Thus, a system that can fulfill the various requirements dictated by the designer is constructed. The performance of the NN controller is compared with that of the PID controller developed for the same purpose, and the values of the performance indices indicate the superiority of the NN controller over that of the classical PID controller

  7. High temperature crevice corrosion of heat-resistant Ni-base alloy in the simulated HTR helium

    International Nuclear Information System (INIS)

    Kiuchi, Kiyoshi; Kondo, Tatsuo

    1980-03-01

    Interaction between a Ni-base heat-resistant alloy and the simulated HTR primary coolant environment was examined with emphasis on the reactions inside narrow crevice gaps. A new method using Mo crevice cells was developed to obtain reproducible quantitative results. The test environment was characterized by the low oxidizing species as trace gaseous impurities. Series of sequential phenomena were observed: i.e. the preferential consumptions of oxidizing species in the outer part of the crevice, followed by the lack of oxide film and the resultant extensive carburization further inside the crevice. A model on the possible phenomena occurring at tips of the cracks formed during creep or fatigue tests and low flow rate portions in the reactor primary circuit as well. The feasibility of the interpretation was checked referring to the existing numerical formula and using the experimental results obtained parameters. Calculations reproduced penetration curves of the Cr- oxidation with reasonable accuracy. (author)

  8. Semi-analytical prediction of hydraulic resistance and heat transfer for pipe and channel flows of water at supercritical pressure

    International Nuclear Information System (INIS)

    Laurien, E.

    2012-01-01

    Within the Generation IV International Forum the Supercritical Water Reactor is investigated. For its core design and safety analysis the efficient prediction of flow and heat transfer parameters such as the wall-shear stress and the heat-transfer coefficient for pipe and channel flows is needed. For circular pipe flows a numerical model based on the one-dimensional conservation equations of mass, momentum end energy in the radial direction is presented, referred to as a 'semi-analytical' method. An accurate, high-order numerical method is employed to evaluate previously derived analytical solutions of the governing equations. Flow turbulence is modeled using the algebraic approach of Prandtl/van-Karman, including a model for the buffer layer. The influence of wall roughness is taken into account by a new modified numerical damping function of the turbulence model. The thermo-hydraulic properties of water are implemented according to the international standard of 1997. This method has the potential to be used within a sub-channel analysis code and as wall-functions for CFD codes to predict the wall shear stress and the wall temperature. The present study presents a validation of the method with comparison of model results with experiments and multi-dimensional computational (CFD) studies in a wide range of flow parameters. The focus is laid on forced convection flows related to reactor design and near-design conditions. It is found, that the method can accurately predict the wall temperature even under deterioration conditions as they occur in the selected experiments (Yamagata el al. 1972 at 24.5 MPa, Ornatski et al. 1971 at 25.5 and Swenson et al. 1963 at 22.75 MPa). Comparison of the friction coefficient under high heat flux conditions including significant viscosity and density reductions near the wall with various correlations for the hydraulic resistance will be presented; the best agreement is achieve with the correlation of Pioro et al. 2004. It is

  9. Effect of heat-treatment with raw cotton seed oil on decay resistance and dimensional stability of Beech (Fagus orientalis

    Directory of Open Access Journals (Sweden)

    مریم قربانی

    2015-05-01

    Full Text Available This research was conducted to determine the effect of heat-treatment with raw cotton seed oil on decay resistance and dimensional stability of beech according to EN113 and ASTM-D1037 standards respectively. The heat treatment with raw cotton seed oil was carried out in the cylinder at the temperatures of 130 and 170oC for 30 and 60 minutes. Oil uptake, density, volumetric swelling, water absorption and weight loss exposed to decay were measured. Oil uptake at 30 and 60 min were determined 10.5 and 13.3 Kg/cm3 respectively. Oil-heat treated samples at 30min and 130°C indicated the maximum density with 87.7% increase. According to results, oil-heat treatment improved water repellency and dimensional stability. Water absorption in 130°C and 60 minutes decreased 76% in comparison with control. Decay resistance of oil soaked samples for 60minutes was 80.2% more than control samples. Oil-heat treatment compared with oil treatment improved decay resistance, this effect was significant at 30 min. The temperature rise of oil–heat treatment at 30 minutes improved decay resistance, but the improvement under same level of temperature with increase time was not significant.

  10. Clozapine-resistant schizophrenia – non pharmacological augmentation methods

    Directory of Open Access Journals (Sweden)

    Gałaszkiewicz Joanna

    2017-12-01

    Full Text Available Clozapine is the drug of choice for drug-resistant schizophrenia, but despite its use, 30-40% patients fail to achieve satisfactory therapeutic effects. In such situations, augmentation attempts are made by both pharmacological and non-pharmacological methods. To date, most of the work has been devoted to pharmacological strategies, much less to augemantation of clozapine with electroconvulsive therapy (C+ECT, transcranial direct current stimulation (tDCS or transcranial magnetic stimulation (TMS.

  11. Effect of heat treatment conditions on stress corrosion cracking resistance of alloy X-750 in high temperature water

    International Nuclear Information System (INIS)

    Yonezawa, Toshio; Onimura, Kichiro; Sakamoto, Naruo; Sasaguri, Nobuya; Susukida, Hiroshi; Nakata, Hidenori.

    1984-01-01

    In order to improve the resistance of the Alloy X-750 in high temperature and high purity water, the authors investigated the influence of heat treatment condition on the stress corrosion cracking resistance of the alloy. This paper describes results of the stress corrosion cracking test and some discussion on the mechanism of the stress corrosion cracking of Alloy X-750 in deaerated high temperature water. The following results were obtained. (1) The stress corrosion cracking resistance of Alloy X-750 in deaerated high temperature water remarkably depended upon the heat treatment condition. The materials solution heat treated and aged within temperature ranges from 1065 to 1100 0 C and from 704 to 732 0 C, respectively, have a good resistance to the stress corrosion cracking in deaerated high temperature water. Especially, water cooling after the solution heat treatment gives an excellent resistance to the stress corrosion cracking in deaerated high temperature water. (2) Any correlations were not observed between the stress corrosion cracking susceptibility of Alloy X-750 in deaerated high temperature water and grain boundary chromium depleted zones, precipitate free zones and the grain boundary segregation of impurity elements and so on. It appears that there are good correlations between the stress corrosion cracking resistance of the alloy in the environment and the kinds, morphology and coherency of precipitates along the grain boundaries. (author)

  12. Homotopy Perturbation Method for Thin Film Flow and Heat Transfer over an Unsteady Stretching Sheet with Internal Heating and Variable Heat Flux

    Directory of Open Access Journals (Sweden)

    I-Chung Liu

    2012-01-01

    Full Text Available We have analyzed the effects of variable heat flux and internal heat generation on the flow and heat transfer in a thin film on a horizontal sheet in the presence of thermal radiation. Similarity transformations are used to transform the governing equations to a set of coupled nonlinear ordinary differential equations. The obtained differential equations are solved approximately by the homotopy perturbation method (HPM. The effects of various parameters governing the flow and heat transfer in this study are discussed and presented graphically. Comparison of numerical results is made with the earlier published results under limiting cases.

  13. An optical method for measuring the thickness of a falling condensate in gravity assisted heat pipe

    Directory of Open Access Journals (Sweden)

    Kasanický Martin

    2015-01-01

    Full Text Available A large number of variables is the main problem of designing systems which uses heat pipes, whether it is a traditional - gravity, or advanced - capillary, pulsating, advanced heat pipes. This article is a methodology for measuring the thickness of the falling condensate in gravitational heat pipes, with using the optical triangulation method, and the evaluation of risks associated with this method.

  14. Effect of the Heat Treatment on the Mechanical Property and Corrosion Resistance of CU - 7Al - 2.5Si Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Syung-Yul; Won, Jong-Pil; Park, Dong-Hyun; Moon, Kyung-Man; Lee, Myeong-Hoon; Jeong, Jin-A [Korea Maritime and Ocean Univ., Busan (Korea, Republic of); Baek, Tae-Sil [Pohang College, Pohang (Korea, Republic of)

    2014-02-15

    Recently, the fuel oil of diesel engines of marine ships has been increasingly changed to heavy oil of low quality as the oil price is getting higher and higher. Therefore, the spiral gear attached at the motor of the oil purifier which plays an important role to purify the heavy oil is also easy to expose at severe environmental condition due to the purification of the heavy oil in higher temperature. Thus, the material of the spiral gear requires a better mechanical strength, wear and corrosion resistance. In this study, the heat treatment(tempering) with various holding time at temperature of 500 .deg. C was carried out to the alloy of Cu-7Al-2.5Si as centrifugal casting, and the properties of both hardness and corrosion resistance with and without heat treatment were investigated with observation of the microstructure and with electrochemical methods, such as measurement of corrosion potential, cathodic and anodic polarization curves, cyclic voltammogram, and a.c. impedance. in natural seawater solution. The α, β and γ{sub 2} phases were observed in the material in spite of no heat treatment due to quenching effect of a spin mold. However, their phases, that is, β and γ{sub 2} phases decreased gradually with increasing the holding time at a constant temperature of 500 .deg. C. The hardness more or less decreased with heat treatment, however its corrosion resistance was improved with the heat treatment. Furthermore, the longer holding time, the better corrosion resistance. In addition, when the holding time was 48hrs, its corrosion current density showed the lowest value. The pattern of corroded surface was nearly similar to that of the pitting corrosion, and this morphology was greatly observed in the case of no heat treatment. It is considered that γ{sub 2} phase at the grain boundary was corroded preferentially as an anode. However, the pattern of general corrosion exhibited increasingly due to decreasing the γ{sub 2} phase with heat treatment

  15. The present state of research into plasma heating and injection methods

    International Nuclear Information System (INIS)

    1974-12-01

    The advantages and disadvantages recognized by the Advisory Group on Heating and injection for twelve plasma heating and injection methods currently under investigation in Europe are related. The heating and injection requirements of four reference reactor designs are previously defined. The problems which arise when one attempts to extrapolate existing work towards the reactor goal are emphasized. Two refuelling methods not directly linked with the heating problem are discussed. The experiments in operation or under construction in Europe in which each method is investigated are listed. Sixteen working papers which served as a basis for the Advisory Group discussion and which cover all the heating and injection methods examined are included

  16. Experimental investigations on heat content of supercooled sodium acetate trihydrate by a simple heat loss method

    DEFF Research Database (Denmark)

    Kong, Weiqiang; Dannemand, Mark; Johansen, Jakob Berg

    2016-01-01

    Sodium acetate trihydrate is a phase change material that can be used for long term heat storage in solar heating systems because of its relatively high heat of fusion, a melting temperature of 58 °C and its ability to supercool stable. In practical applications sodium acetate trihydrate tend to ......, 0.3–0.5 % (wt.%) Xanthan Gum or 1–2% (wt.%) of some solid or liquid polymers as additives had significantly higher heat contents compared to samples of sodium acetate trihydrate suffering from phase separation....

  17. Estimation of Surface Temperature and Heat Flux by Inverse Heat Transfer Methods Using Internal Temperatures Measured While Radiantly Heating a Carbon/Carbon Specimen up to 1920 F

    Science.gov (United States)

    Pizzo, Michelle; Daryabeigi, Kamran; Glass, David

    2015-01-01

    The ability to solve the heat conduction equation is needed when designing materials to be used on vehicles exposed to extremely high temperatures; e.g. vehicles used for atmospheric entry or hypersonic flight. When using test and flight data, computational methods such as finite difference schemes may be used to solve for both the direct heat conduction problem, i.e., solving between internal temperature measurements, and the inverse heat conduction problem, i.e., using the direct solution to march forward in space to the surface of the material to estimate both surface temperature and heat flux. The completed research first discusses the methods used in developing a computational code to solve both the direct and inverse heat transfer problems using one dimensional, centered, implicit finite volume schemes and one dimensional, centered, explicit space marching techniques. The developed code assumed the boundary conditions to be specified time varying temperatures and also considered temperature dependent thermal properties. The completed research then discusses the results of analyzing temperature data measured while radiantly heating a carbon/carbon specimen up to 1920 F. The temperature was measured using thermocouple (TC) plugs (small carbon/carbon material specimens) with four embedded TC plugs inserted into the larger carbon/carbon specimen. The purpose of analyzing the test data was to estimate the surface heat flux and temperature values from the internal temperature measurements using direct and inverse heat transfer methods, thus aiding in the thermal and structural design and analysis of high temperature vehicles.

  18. A study on the effect of solution heat treatment on the corrosion resistance of super duplex stainless steels

    International Nuclear Information System (INIS)

    Park, Jee Yong; Park, Yong Soo; Kim, Soon Tae

    2001-01-01

    High temperature solution heat treatment(typically higher than 1100 .deg. C) is known generally to reduces the resistance to localized corrosion on super duplex stainless. This is attributed to the formation of zone depleted of alloying elements. In this study, the corrosion properties were investigated on super duplex stainless steels with various solution heat treatments. The corrosion resistance of these steels was evaluated in terms of critical pitting temperature and cyclic potentiodynamic polarization test. Chemical composition of the austenite and ferrite phases were analyzed by SEM-EDS. The following results were obtained. (1) By conducting furnace cooling, critical pitting temperature and repassivation potential increased. (2) By omitting furnace cooling, solution heat treatment produced Cr and Mo depleted zone in the phase boundary. (3) During furnace cooling, Cr and Mo rediffused through the phase boundary. This increased the corrosion resistance of super duplex stainless steels

  19. High Magnetic Field Processing - A Heat-Free Heat Treating Method

    Energy Technology Data Exchange (ETDEWEB)

    Ludtka, Gerard Michael [ORNL; Ludtka, Gail Mackiewicz- [ORNL; Wilgen, John B [ORNL; Kenik, Edward A [ORNL; Parish, Chad M [ORNL; Rios, Orlando [ORNL; Rogers, Hiram [ORNL; Manuel, Michele [University of Florida, Gainesville; Kisner, Roger A [ORNL; Watkins, Thomas R [ORNL; Murphy, Bart L [ORNL

    2012-08-01

    The High and Thermal Magnetic Processing/Electro-magnetic Acoustic Transducer (HTMP/EMAT) technology has been shown to be an enabling disruptive materials processing technology, that can achieve significant improvements in microstructure and consequently material performance beyond that achievable through conventional processing, and will lead to the next generation of advanced performance structural and functional materials. HTMP exposure increased the reaction kinetics enabling refinement of microstructural features such as finer martensite lath size, and finer, more copious, homogeneous dispersions of strengthening carbides leading to combined strength and toughness improvements in bainitic steels. When induction heating is applied in a high magnetic field environment, the induction heating coil is configured so that high intensity acoustic/ultrasonic treatment occurs naturally. The configuration results in a highly effective electromagnetic acoustical transducer (EMAT). HTMP combined with applying high-field EMAT, produce a non-contact ultrasonic treatment that can be used to process metal alloys in either the liquid state resulting in significant microstructural changes over conventional processing. Proof-of-principle experiments on cast irons resulted in homogeneous microstructures in small castings along with improved casting surface appearance. The experiment showed that by exposing liquid metal to the non-contact acoustic/ultrasonic processing technology developed using HMFP/EMAT wrought-like microstructures were developed in cast components. This Energy Intensive Processes (EIP) project sponsored by the DOE EERE Advanced Manufacturing Office (AMO) demonstrated the following: (1) The reduction of retained austenite in high carbon/high alloy steels with an ambient temperature HTMP process, replacing either a cryogenic or double tempering thermal process normally employed to accomplish retained austenite transformation. HTMP can be described as a 'heat

  20. Resistivity Correction Factor for the Four-Probe Method: Experiment I

    Science.gov (United States)

    Yamashita, Masato; Yamaguchi, Shoji; Enjoji, Hideo

    1988-05-01

    Experimental verification of the theoretically derived resistivity correction factor (RCF) is presented. Resistivity and sheet resistance measurements by the four-probe method are made on three samples: isotropic graphite, ITO film and Au film. It is indicated that the RCF can correct the apparent variations of experimental data to yield reasonable resistivities and sheet resistances.

  1. Heat transfer in Rockwool modelling and method of measurement. Modelling radiative heat transfer in fibrous materials

    Energy Technology Data Exchange (ETDEWEB)

    Dyrboel, Susanne

    1998-05-01

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

  2. Thermal, epithermal and thermalized neutron attenuation properties of ilmenite-serpentine heat resistant concrete shield

    International Nuclear Information System (INIS)

    Kany, A.M.I.; El-Gohary, M.I.; Kamal, S.M.

    1994-01-01

    Experimental measurements were carried out to study the attenuation properties of low-energy neutrons transmitted through unheated and preheated barriers of heavy-weight, highly hydrated and heat-resistant concrete shields. The concrete shields under investigation have been prepared from naturally occurring ilmenite and serpentine Egyptian ores. A collimated beam obtained from an Am-Be source was used as a source of neutrons, while the measurements of total thermal, epithermal, and thermalized neutron fluxes were performed using a BF-3 detector, multichannel analyzer and Cd filter. Results show that the ilmenite-serpentine concrete proved to be a better thermal, epithermal and thermalized neutron attenuator than the ordinary concrete especially at a high temperature of concrete exposure. (Author)

  3. Applicability of creep damage rules to a nickel-base heat-resistant alloy Hastelloy XR

    International Nuclear Information System (INIS)

    Tsuji, Hirokazu; Nakajima, Najime; Tanabe, Tatsuhiko; Nakasone, Yuji

    1992-01-01

    A series of constant load and temperature creep rupture tests and varying load and/or temperature creep rupture tests was carried out on a nickel-base heat-resistant alloy Hastelloy XR, which was developed for applications in the High-Temperature Engineering Test Reactor, at temperatures ranging from 850 to 1000deg C in order to examine the applicability of the conventional creep damage rules, i.e., the life fraction, the strain fraction and their mixed rules. The life fraction rule showed the best applicability of these three criteria. The good applicability of the rule was considered to result from the fact that the creep strength of Hastelloy XR was not strongly affected by the change of the chemical composition and/or the microstructure during exposure to the high-temperature simulated HTGR helium environment. In conclusion the life fraction rule is applicable in engineering design of high-temperature components made of Hastelloy XR. (orig.)

  4. Estimating the Condition of the Heat Resistant Lining in an Electrical Reduction Furnace

    Directory of Open Access Journals (Sweden)

    Jan G. Waalmann

    1988-01-01

    Full Text Available This paper presents a system for estimating the condition of the heat resistant lining in an electrical reduction furnace for ferrosilicon. The system uses temperature measured with thermocouples placed on the outside of the furnace-pot. These measurements are used together with a mathematical model of the temperature distribution in the lining in a recursive least squares algorithm to estimate the position of 'the transformation front'. The system is part of a monitoring system which is being developed in the AIP-project: 'Condition monitoring of strongly exposed process equipment in thc ferroalloy industry'. The estimator runs on-line, and results arc presented in colour-graphics on a display unit. The goal is to locate the transformation front with an accuracy of +- 5cm.

  5. Preparation of flexible and heat-resisting conductive transparent film by the pyrosol process

    International Nuclear Information System (INIS)

    Usami, Hisanao; Nakasa, Akihiko; Adachi, Mami; Suzuki, Eiji; Fujimatsu, Hitoshi; Ohashi, Tatsuya; Yamada, Shigeo; Tsugita, Kouhei; Taniguchi, Yoshio

    2006-01-01

    A pyrosol process was successfully applied for the preparation of a flexible, conductive, and transparent inorganic film, a tin-doped indium oxide (ITO) film lined with a thin mica layer. This flexible heat-resistant ITO-mica film exhibited high conductivity and transparency, comparable to ITO deposited on glass substrate. The minimum radius of bending for the film, without any recognizable change in the conductivity and appearance, was 8 mm. The ITO deposited on mica showed a large (222) diffraction peak with a smaller (400) peak, in contrast to ITO deposited with (400) orientation on an ordinary glass substrate. Using the ITO-mica film, a prototype model of a flexible organic light emitting diode was fabricated

  6. Development of halogen-free, heat-resistant, low-voltage wire for automotive use

    International Nuclear Information System (INIS)

    Ueno, Keiji; Suzuki, Sizuo; Takahagi, Masatoshi; Uda, Ikujiro

    1995-01-01

    The environmental load of our motorized society is of major concern, and includes considerations of recycling of automotive parts as the industrial wastes. The total average length of AV, AVX (electrical wire insulated with PVC, cross-linked PVC), and AEX (electrical wire insulated with cross-linked polyolefin) wires required for the harnesses in modern automobiles is approximately 2,000-3,000 meters per unit. However these electrical wires contain a large amount of halogen, which can generate the smoke and corrosive gas. In response to this problem the authors have developed the electron beam irradiated halogen-free, heat-resistant, low-voltage electrical wire which does not contain any halogen based polymer or flame retardants. The developed wire features the reliability equivalent to AEX wire with minimum environmental load. (Author)

  7. Modelling of Dynamic Transmission Cable Temperature Considering Soil-Specific Heat, Thermal Resistivity, and Precipitation

    DEFF Research Database (Denmark)

    Olsen, Rasmus; Anders, George J.; Holboell, Joachim

    2013-01-01

    This paper presents an algorithm for the estimation of the time-dependent temperature evolution of power cables, when real-time temperature measurements of the cable surface or a point within its vicinity are available. The thermal resistivity and specific heat of the cable surroundings are varied...... as functions of the moisture content which is known to vary with time. Furthermore, issues related to the cooling effect during rainy weather are considered. The algorithm is based on the lumped parameters model and takes as input distributed temperature sensing measurements as well as the current and ambient...... temperature. The concept is verified by studying a laboratory setup of a 245 kV cable system....

  8. Standard classification of resistance to stress-corrosion cracking of heat-treatable Aluminum alloys

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 This classification covers alphabetical ratings of the relative resistance to SCC of various mill product forms of the wrought 2XXX, 6XXX, and 7XXX series heat-treated aluminum alloys and the procedure for determining the ratings. 1.2 The ratings do not apply to metal in which the metallurgical structure has been altered by welding, forming, or other fabrication processes. 1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  9. TEM characterization of microstructure evolution of 12%Cr heat resistant steels

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, D.; Prat, O.; Sauthoff, G. [Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany); Garcia, J. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany); Kaysser-Pyzalla, A.R. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany); Bochum Univ. (Germany)

    2010-07-01

    A detailed characterization of the microstructure evolution of 12%Cr heat resistant steels at different creep times (100 MPa / 650 C / 8000 h) were carried out by scanning transmission electron microscopy (STEM). The results of the microstructure analysis are correlated with the mechanical properties in order to investigate the influence of different precipitates (especially M{sub 23}C{sub 6}) on the creep strength of the alloys. Precipitation of Laves phase and Z-phase was observed after several hours creep time. Very few Z-phase of the type Cr(V,Ta)N nucleating from existing (V,Ta)(C,N) was observed. Both alloys show growth and coarsening of Laves phase, meanwhile the MX carbonitrides present a very slow growth and coarsening rate. Alloys containing Laves phase, MX and M{sub 23}C{sub 6} precipitates show best creep properties. (orig.)

  10. Heat Transfer Analysis of Methane Hydrate Sediment Dissociation in a Closed Reactor by a Thermal Method

    Directory of Open Access Journals (Sweden)

    Mingjun Yang

    2012-05-01

    Full Text Available The heat transfer analysis of hydrate-bearing sediment involved phase changes is one of the key requirements of gas hydrate exploitation techniques. In this paper, experiments were conducted to examine the heat transfer performance during hydrate formation and dissociation by a thermal method using a 5L volume reactor. This study simulated porous media by using glass beads of uniform size. Sixteen platinum resistance thermometers were placed in different position in the reactor to monitor the temperature differences of the hydrate in porous media. The influence of production temperature on the production time was also investigated. Experimental results show that there is a delay when hydrate decomposed in the radial direction and there are three stages in the dissociation period which is influenced by the rate of hydrate dissociation and the heat flow of the reactor. A significant temperature difference along the radial direction of the reactor was obtained when the hydrate dissociates and this phenomenon could be enhanced by raising the production temperature. In addition, hydrate dissociates homogeneously and the temperature difference is much smaller than the other conditions when the production temperature is around the 10 °C. With the increase of the production temperature, the maximum of ΔToi grows until the temperature reaches 40 °C. The period of ΔToi have a close relation with the total time of hydrate dissociation. Especially, the period of ΔToi with production temperature of 10 °C is twice as much as that at other temperatures. Under these experimental conditions, the heat is mainly transferred by conduction from the dissociated zone to the dissociating zone and the production temperature has little effect on the convection of the water in the porous media.

  11. Comparison of Chemical Sensitivity of Fresh and Long-Stored Heat Resistant Neosartorya fischeri Environmental Isolates Using BIOLOG Phenotype MicroArray System.

    Directory of Open Access Journals (Sweden)

    Jacek Panek

    Full Text Available Spoilage of heat processed food and beverage by heat resistant fungi (HRF is a major problem for food industry in many countries. Neosartorya fischeri is the leading source of spoilage in thermally processed products. Its resistance to heat processing and toxigenicity makes studies about Neosartorya fischeri metabolism and chemical sensitivity essential. In this study chemical sensitivity of two environmental Neosartorya fischeri isolates were compared. One was isolated from canned apples in 1923 (DSM3700, the other from thermal processed strawberry product in 2012 (KC179765, used as long-stored and fresh isolate, respectively. The study was conducted using Biolog Phenotype MicroArray platforms of chemical sensitivity panel and traditional hole-plate method. The study allowed for obtaining data about Neosartorya fischeri growth inhibitors. The fresh isolate appeared to be much more resistant to chemical agents than the long-stored isolate. Based on phenotype microarray assay nitrogen compounds, toxic cations and membrane function compounds were the most effective in growth inhibition of N. fischeri isolates. According to the study zaragozic acid A, thallium(I acetate and sodium selenate were potent and promising N. fischeri oriented fungicides which was confirmed by both chemical sensitivity microplates panel and traditional hole-plate methods.

  12. Method of manufacturing a shapeable short-resistant capacitor

    Science.gov (United States)

    Taylor, Ralph S.; Myers, John D.; Baney, William J.

    2013-04-02

    A method that employs a novel combination of conventional fabrication techniques provides a ceramic short-resistant capacitor that is bendable and/or shapeable to provide a multiple layer capacitor that is extremely compact and amenable to desirable geometries. The method allows thinner and more flexible ceramic capacitors to be made. The method includes forming a first thin metal layer on a substrate; depositing a thin, ceramic dielectric layer over the metal layer; depositing a second thin metal layer over the dielectric layer to form a capacitor exhibiting a benign failure mode; and separating the capacitor from the substrate. The method may also include bending the resulting capacitor into a serpentine arrangement with gaps between the layers that allow venting of evaporated electrode material in the event of a benign failure.

  13. A comparison of different methods for in-situ determination of heat losses form district heating pipes

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Benny [Technical Univ. of Denmark, Dept. of Energy Engineering (Denmark)

    1996-11-01

    A comparison of different methods for in-situ determination of heat losses has been carried out on a 273 mm transmission line in Copenhagen. Instrumentation includes temperature sensors, heat flux meters and an infrared camera. The methods differ with regard to time consumption and costs of applying the specific method, demand on accuracy of temperature measurements, sensitivity to computational parameters, e.g. the thermal conductivity of the soil, response to transients in water temperature and the ground, and steady state assumptions in the model used in the interpretation of the measurements. Several of the applied methods work well. (au)

  14. Description of heat flux measurement methods used in hydrocarbon and propellant fuel fires at Sandia.

    Energy Technology Data Exchange (ETDEWEB)

    Nakos, James Thomas

    2010-12-01

    The purpose of this report is to describe the methods commonly used to measure heat flux in fire applications at Sandia National Laboratories in both hydrocarbon (JP-8 jet fuel, diesel fuel, etc.) and propellant fires. Because these environments are very severe, many commercially available heat flux gauges do not survive the test, so alternative methods had to be developed. Specially built sensors include 'calorimeters' that use a temperature measurement to infer heat flux by use of a model (heat balance on the sensing surface) or by using an inverse heat conduction method. These specialty-built sensors are made rugged so they will survive the environment, so are not optimally designed for ease of use or accuracy. Other methods include radiometers, co-axial thermocouples, directional flame thermometers (DFTs), Sandia 'heat flux gauges', transpiration radiometers, and transverse Seebeck coefficient heat flux gauges. Typical applications are described and pros and cons of each method are listed.

  15. Data on post irradiation experiments of heat resistant ceramic composite materials. PIE for 97M-13A

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Shin-ichi; Ishihara, Masahiro; Souzawa, Shizuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Sekino, Hajime [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The research on the radiation damage mechanism of heat resistant ceramic composite materials is one of the research subjects of the innovative basic research in the field of high temperature engineering, using the High Temperature engineering Test Reactor (HTTR). Three series of irradiation tests on the heat resistant ceramic composite materials, first to third irradiation test program, were carried out using the Japan Material Testing Reactor (JMTR). This is a summary report on the first irradiation test program; irradiation induced dimensional change, thermal expansion coefficient, X-ray diffraction and {gamma}-ray spectrum are reported. (author)

  16. A Method of Heat Exchange Structure Optimization of the Cricoid Plastic Parts

    Directory of Open Access Journals (Sweden)

    Dongpo Yang

    2014-01-01

    Full Text Available This paper research on the effect of heat transfer performance of ring wall structure change of ship water heater top cricoid hood. A method of equivalent conversion is applied on simplify the structure of finned tube heat exchanger, it distinct reduce the computational grid, and improve the simulation speed and accuracy. This method can be used to calculate the ventilation and heat transfer of that compact configuration type structure in the complex component. Changing the ring wall structure can improve heat transfer performance, based on the method of equivalent transformation, a new heat transfer structure is established.

  17. In vitro screening methods for assessing plant disease resistance

    International Nuclear Information System (INIS)

    Lebeda, A.; Svabova, L.

    2010-01-01

    A combination of biotechnological and phytopathological techniques provides an alternative approach to classical resistance breeding methods. Such techniques have been increasingly used since the 1980s, in parallel with the progress in plant biotechnology. In the approach of resistance screening and selection in vitro, both experimental objects, i.e., the plant and the pathogen, must first be transferred to in vitro conditions, and finally, the plant material must be transferred back to in vivo conditions and adapted to the outside settings. Specific attention must be paid to the methods of pathogen preparation for use in screening and selection in vitro. The selection agents are classified according to their origin, the methods of preparation, nature and content of active substances, and effective utilisation for screening or selection in vitro. Basic principles and methodological aspects of the in vitro work (explant cultures, sources of in vitro variability, screening and selection methods, types of selection agents) as well as examples of practical applications in the breeding of different crops are critically reviewed in this chapter. (author)

  18. Solution to Two-Dimensional Steady Inverse Heat Transfer Problems with Interior Heat Source Based on the Conjugate Gradient Method

    Directory of Open Access Journals (Sweden)

    Shoubin Wang

    2017-01-01

    Full Text Available The compound variable inverse problem which comprises boundary temperature distribution and surface convective heat conduction coefficient of two-dimensional steady heat transfer system with inner heat source is studied in this paper applying the conjugate gradient method. The introduction of complex variable to solve the gradient matrix of the objective function obtains more precise inversion results. This paper applies boundary element method to solve the temperature calculation of discrete points in forward problems. The factors of measuring error and the number of measuring points zero error which impact the measurement result are discussed and compared with L-MM method in inverse problems. Instance calculation and analysis prove that the method applied in this paper still has good effectiveness and accuracy even if measurement error exists and the boundary measurement points’ number is reduced. The comparison indicates that the influence of error on the inversion solution can be minimized effectively using this method.

  19. Effect of test temperature on tensile and fatigue properties of nickel-base heat-resistant alloys

    International Nuclear Information System (INIS)

    Tsuji, Hirokazu; Nakajima, Hajime

    1987-01-01

    A series of tensile and strain controlled low-cycle fatigue tests were conducted at temperatures ranging from RT to 900 0 C on a nickel-base heat-resistant alloy, Hastelloy XR-II, which is one of the candidate alloys for applications in the process heating high-temperature gas-cooled reactor (HTGR). Fatigue tests at room temperature and all tensile tests were conducted in air, while fatigue tests at and above 400 0 C were conducted in the simulated HTGR helium environment. In those tests the effect of test temperature on tensile and fatigue properties was investigated. The ductility minimum point was observed near 600 0 C, while tensile and fatigue strengths decreased with increasing test temperature. The fatigue lives estimated with the method proposed by Manson were compatible with the experimental results under the given conditions. For the specimens fatigued at and above 700 0 C, the percentage of the intergranular fracture mode gradually increased with increasing test temperature. (orig.)

  20. RESEARCH OF HEAT-RESISTANT CONCRETE ON THE BASIS OF BASALT FILLER FOR CONCRETING OF METAL DESIGNS

    Directory of Open Access Journals (Sweden)

    R. M. Curbanov

    2013-01-01

    Full Text Available Expediency of use of heat-resistant concrete locates in article on the basis of a basalt filler. It is thin a ground additive promotes increase in power of internal friction between material particles. With increase in power of internal friction between particles viscosity knitting increases and as a result ryazmyagcheniye temperature under loading increases and fire resistance of a material increases

  1. Characterization and radiation response of a heat-resistant variant of V79 cells

    International Nuclear Information System (INIS)

    Campbell, S.D.; Kruuv, J.; Lepock, J.R.

    1983-01-01

    A thermoresistant variant of the established cell line V79-S171-W1 was isolated after treatment with nitrosoguanidine and repeated heat treatments at 42.6 to 43 degrees C, and showed an enhanced ability to survive at 42.6, 43.5, and 44.5 degrees C. The rates of inactivation of the normal and heat-resistant lines differed by approximately a factor of 2 over this temperature range. This level of thermoresistance was stable for the first 80 doublings, but was lost by 120 doublings. This may have been due to a reversion to the normal V79 line since there was no continuous selection pressure and the thermoresistant variant, which was designated at HR7, had a longer average doubling time. Transient thermotolerance was induced in both the V79 and HR7 cells by a 10-min exposure to 44.5 degrees C. After 3 hr incubation at 37 degrees C, both cell lines had an identical sensitivity to further exposure to 44.5 degrees C. Thus the long-term thermoresistance of the HR7 cells may be due to a permanent induction of a low level of thermotolerance. The (ionizing) radiation survival curves and the ability to repair sublethal radiation damage were identical for the thermoresistant variant and the parent cell line

  2. Improvement of corrosion resistance of Ni−Mo alloy coatings: Effect of heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Mousavi, R., E-mail: mousavi@scu.ac.ir [Department of Materials Science and Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Bahrololoom, M.E. [Department of Materials Science and Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Deflorian, F.; Ecco, L. [Department of Industrial Engineering, University of Trento, via Sommarive 9, Trento (Italy)

    2016-02-28

    Graphical abstract: - Highlights: • Conjunction between SEM, EIS, and Tafel measurements to obtain a coat with dense morphology and without crack. • An inverse Hall-Petch effect is observed after annealing the coatings, i.e. the coatings get harder as the grain size is increased by increasing annealing temperature up to 600 {sup o}C. • Heat treatment can improve the mechanical and corrosion properties of coatings. - Abstract: In this paper, Ni−Mo alloy coatings were deposited from bath containing sodium citrate, nickel sulphate, and sodium molybdate. Essentially, this work is divided into two mains parts: (i) the optimization on the coatings deposition parameters and (ii) the effect of the heat treatment. Polarization curves and electrochemical impedance spectroscopy were acquired using potentiostat/galvanostat and a frequency response analyzer, respectively. Morphology and chemical composition of the coatings were investigated by scanning electron microscopy and energy dispersive spectroscopy, respectively. Polarization curves at different condition revealed that electroplating at temperature 40 {sup o}C, pH 9 provides a dense coating with high efficiency. Following the optimization of the deposition parameters, the coatings were annealed at 200, 400, and 600 {sup o}C for 25 min. The results showed that the coatings obtained at temperature 40 {sup o}C, pH 9, and annealing at 600 {sup o}C has the highest corrosion resistance and microhardness.

  3. The one-parameter-model - a constitutive equation applied to a heat resistant alloy

    International Nuclear Information System (INIS)

    Schwarze, E.; Schuster, H.; Nickel, H.

    1992-01-01

    In the present work a constitutive model earlier developed and used to predict experimental results of hot tests and fatigue tests from creep experiments of metallic materials were modified to comply with the properties of a high temperature resistant material. The improved model accounts for the properties of a material developing a density and a structure of dislocation lines which are capable of interactions with particles (carbides) from a second phase. The time and temperature dependent evolution of the carbide structure has been described by an equation which explains the formation of seeds as well as their growths (Ostwald ripening). The extended model was applied to Incoloy 800H which is known to develop a carbide structure. Therefore hot tensile and fatigue tests, creep and relaxation experiments using the heats ADU and BAK (KFA specifications) at temperature between 800deg C and 900deg C were performed including both solution treated specimens and specimens heat treated for 10, 100 and 1000 hours. As compared with the results from tensile tests where the carbide structures play a subordinated role, alternately, these structures have a decisive influence on the creep properties of specimens during the primary creep phase, i.e. low stresses and high temperatures. (orig.) [de

  4. Global analysis of the temperature and flow fields in samples heated in multizone resistance furnaces

    Science.gov (United States)

    Pérez-Grande, I.; Rivas, D.; de Pablo, V.

    The temperature field in samples heated in multizone resistance furnaces will be analyzed, using a global model where the temperature fields in the sample, the furnace and the insulation are coupled; the input thermal data is the electric power supplied to the heaters. The radiation heat exchange between the sample and the furnace is formulated analytically, taking into account specular reflections at the sample; for the solid sample the reflectance is both diffuse and specular, and for the melt it is mostly specular. This behavior is modeled through the exchange view factors, which depend on whether the sample is solid or liquid, and, therefore, they are not known a priori. The effect of this specular behavior in the temperature field will be analyzed, by comparing with the case of diffuse samples. A parameter of great importance is the thermal conductivity of the insulation material; it will be shown that the temperature field depends strongly on it. A careful characterization of the insulation is therefore necessary, here it will be done with the aid of experimental results, which will also serve to validate the model. The heating process in the floating-zone technique in microgravity conditions will be simulated; parameters like the Marangoni number or the temperature gradient at the melt-crystal interface will be estimated. Application to the case of compound samples (graphite-silicon-graphite) will be made; the temperature distribution in the silicon part will be studied, especially the temperature difference between the two graphite rods that hold the silicon, since it drives the thermocapillary flow in the melt. This flow will be studied, after coupling the previous model with the convective effects. The possibility of suppresing this flow by the controlled vibration of the graphite rods will be also analyzed. Numerical results show that the thermocapillary flow can indeed be counterbalanced quite effectively.

  5. Earthquake resistance of residual heat removed (RHR) pump for pressurized water reactors (PWR)

    International Nuclear Information System (INIS)

    Uga, Takeo; Shiraki, K.; Honma, T.; Matsubayashi, H.; Inazuka, H.

    1980-01-01

    The present paper deals with the earthquake resistance of the residual heat removed (RHR) pump of single stage double volute type, which is one of the structurally simplest pumps used for pressurized water reactors (PWR). The results of the study can be summarized as follows: (1) Any trouble which can give effect on the functions of the pump at earthquake does not become a problem so long as each part of the pump is of aseismatically rigid structure. (2) Aseismatic tolerance test in the pump's operating condition has shown that the earthquake resistance of the pump at its location has a tolerance about five times the dynamic design acceleration. (3) The pump is provided with an impeller-casing wear ring at the pressure boundary between the suction side pressure and discharge side pressure. This wear ring acts as an underwater bearing when the pump is in operation, and improves the vibration characteristics, particularly damping ratio, of the pump shaft to a great extent to make the pump more aseismatic. (4) In the evaluation of the underwater bearing characteristics of the wear ring, the evaluation accuracy of the vibration characteristics of the pump shaft can be improved by taking into consideration the pressure loss in the wear ring part from the head of the single stage of the pump due to the rotation of the impeller. (author)

  6. USING SESSION RPE TO MONITOR DIFFERENT METHODS OF RESISTANCE EXERCISE

    Directory of Open Access Journals (Sweden)

    Alison D. Egan

    2006-06-01

    Full Text Available The purpose of this study was to compare session rating of perceived exertion for different resistance training techniques in the squat exercise. These techniques included traditional resistance training, super slow, and maximal power training. Fourteen college-age women (Mean ± SD; age = 22 ± 3 years; height = 1.68 ± 0. 07 m completed three experimental trials in a randomized crossover design. The traditional resistance training protocol consisted of 6 sets of 6 repetitions of squats using 80% of 1-RM. The super slow protocol consisted of 6 sets of 6 repetitions using 55% of 1-RM. The maximal power protocol consisted of 6 sets of 6 repetitions using 30% of 1-RM. Rating of perceived exertion (RPE measures were obtained following each set using Borg's CR-10 scale. In addition, a session RPE value was obtained 30 minutes following each exercise session. When comparing average RPE and session RPE, no significant difference was found. However, power training had significantly lower (p < 0.05 average and session RPE (4.50 ± 1.9 and 4.5 ± 2.1 compared to both super slow training (7.81 ± 1.75 and 7.43 ± 1.73 and traditional training (7.33 ± 1.52 and 7.13 ± 1.73. The results indicate that session RPE values are not significantly different from the more traditional methods of measuring RPE during exercise bouts. It does appear that the resistance training mode that is used results in differences in perceived exertion that does not relate directly to the loading that is used. Using session RPE provides practitioners with the same information about perceived exertion as the traditional RPE measures. Taking a single measure following a training session would appear to be much easier than using multiple measures of RPE throughout a resistance training workout. However, practitioners should also be aware that the RPE does not directly relate to the relative intensity used and appears to be dependent on the mode of resistance exercise that is used

  7. The heat recovery with heat transfer methods from solar photovoltaic systems

    International Nuclear Information System (INIS)

    Özakın, A. N.; Karsli, S.; Kaya, F.; Güllüce, H.

    2016-01-01

    Although there are many fluctuations in energy prices, they seems like rising day by day. Thus energy recovery systems have increasingly trend. Photovoltaic systems converts solar radiation directly into electrical energy thanks to semiconductors. But due to the nature of semiconductors, whole of solar energy cannot turn into electrical energy and the remaining energy turns into waste heat. The aim of this research is evaluate this waste heat energy by air cooling system. So, the energy efficiency of the system will be increased using appropriate heat transfer technologies such as fin, turbulator etc. (paper)

  8. Analytical methods of heat transfer compared with numerical methods as related to nuclear waste repositories

    International Nuclear Information System (INIS)

    Estrada-Gasca, C.A.

    1986-01-01

    Analytical methods were applied to the prediction of the far-field thermal impact of a nuclear waste repository. Specifically, the transformation of coordinates and the Kirchhoff transformation were used to solve one-dimensional nonlinear heat conduction problems. Calculations for the HLW and TRU nuclear waste with initial areal thermal loadings of 12 kW/acre and 0.7 kW/acre, respectively, are carried out for various models. Also, finite difference and finite element methods are applied. The last method is used to solve two-dimensional linear and nonlinear heat conduction problems. Results of the analysis are temperature distributions and temperature histories. Explicit analytical expressions of the maximum temperature rise as a function of the system parameters are presented. The theoretical approaches predict maximum temperature increases in the overburden with an error of 10%. When the finite solid one-dimensional NWR thermal problem is solved with generic salt and HLW thermal load as parameters, the maximum temperature rises predicted by the finite difference and finite element methods had maximum errors of 2.6 and 6.7%, respectively. In all the other cases the finite difference method also gave a smaller error than the finite element method

  9. Method for utilizing decay heat from radioactive nuclear wastes

    International Nuclear Information System (INIS)

    Busey, H.M.

    1974-01-01

    Management of radioactive heat-producing waste material while safely utilizing the heat thereof is accomplished by encapsulating the wastes after a cooling period, transporting the capsules to a facility including a plurality of vertically disposed storage tubes, lowering the capsules as they arrive at the facility into the storage tubes, cooling the storage tubes by circulating a gas thereover, employing the so heated gas to obtain an economically beneficial result, and continually adding waste capsules to the facility as they arrive thereat over a substantial period of time

  10. Heat transfer simulation of motorcycle fins under varying velocity using CFD method

    Science.gov (United States)

    Shahril, K.; Mohd Kasim, Nurhayati Binti; Sabri, M.

    2013-12-01

    Motorcycle engine releases heat to the atmosphere through the mode of force convection. To solve this, fins are provided on the outer of the cylinder. The heat transfer rate is defined depending on the velocity of vehicle, fin geometry and the ambient temperature. Increasing the temperature difference between the object and the environment, increasing the convection heat transfer coefficient, or increasing the surface area of the object increases the heat transfer. Many experimental methods are available in literature to analyze the effect of these factors on the heat transfer rate. However, CFD analysis will be use to simulate the heat transfer of the engine block. ANSYS software is selected to run the simulation.

  11. Seismic passive earth resistance using modified pseudo-dynamic method

    Science.gov (United States)

    Pain, Anindya; Choudhury, Deepankar; Bhattacharyya, S. K.

    2017-04-01

    In earthquake prone areas, understanding of the seismic passive earth resistance is very important for the design of different geotechnical earth retaining structures. In this study, the limit equilibrium method is used for estimation of critical seismic passive earth resistance for an inclined wall supporting horizontal cohesionless backfill. A composite failure surface is considered in the present analysis. Seismic forces are computed assuming the backfill soil as a viscoelastic material overlying a rigid stratum and the rigid stratum is subjected to a harmonic shaking. The present method satisfies the boundary conditions. The amplification of acceleration depends on the properties of the backfill soil and on the characteristics of the input motion. The acceleration distribution along the depth of the backfill is found to be nonlinear in nature. The present study shows that the horizontal and vertical acceleration distribution in the backfill soil is not always in-phase for the critical value of the seismic passive earth pressure coefficient. The effect of different parameters on the seismic passive earth pressure is studied in detail. A comparison of the present method with other theories is also presented, which shows the merits of the present study.

  12. Standard Test Method for Abrasive Wear Resistance of Cemented

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This test method covers the determination of abrasive wear resistance of cemented carbides. 1.2 The values stated in inch-pound units are to be regarded as the standard. The SI equivalents of inch-pound units are in parentheses and may be approximate. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  13. Standard test method for measurement of soil resistivity using the two-electrode soil box method

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This test method covers the equipment and a procedure for the measurement of soil resistivity, for samples removed from the ground, for use in the control of corrosion of buried structures. 1.2 Procedures allow for this test method to be used n the field or in the laboratory. 1.3 The test method procedures are for the resistivity measurement of soil samples in the saturated condition and in the as-received condition. 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. Soil resistivity values are reported in ohm-centimeter. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.

  14. Variation in Resistance of Natural Isolates of Escherichia coli O157 to High Hydrostatic Pressure, Mild Heat, and Other Stresses

    Science.gov (United States)

    Benito, Amparo; Ventoura, Georgia; Casadei, Maria; Robinson, Tobin; Mackey, Bernard

    1999-01-01

    Strains of Escherichia coli O157 isolated from patients with clinical cases of food-borne illness and other sources exhibited wide differences in resistance to high hydrostatic pressure. The most pressure-resistant strains were also more resistant to mild heat than other strains. Strain C9490, a representative pressure-resistant strain, was also more resistant to acid, oxidative, and osmotic stresses than the pressure-sensitive strain NCTC 12079. Most of these differences in resistance were observed only in stationary-phase cells, the only exception being acid resistance, where differences were also apparent in the exponential phase. Membrane damage in pressure-treated cells was revealed by increased uptake of the fluorescent dyes ethidium bromide and propidium iodide. When strains were exposed to the same pressure for different lengths of time, the pressure-sensitive strains took up stain sooner than the more resistant strain, which suggested that the differences in resistance may be related to susceptibility to membrane damage. Our results emphasize the importance of including stress-resistant strains of E. coli O157 when the efficacy of a novel or mild food preservation treatment is tested. PMID:10103251

  15. Method and equipment to utilize solar heat. [paraffin used as heat storage material

    Energy Technology Data Exchange (ETDEWEB)

    Poellein, H

    1976-09-16

    In this process, solar radiation is converted into heat by means of absorbers. The heat transferred to a liquid is led in forced circulation, first into a heat storage device and then into a water heater. The cooled-down liquid is rercirculated. The storage material used here is paraffin. A measuring and control device is provided to switch from periods with solar radiation to periods where only stored energy is consumed. This device consists of a photocell measuring the incoming sunlight and a temperarure sensor. The control system is put into operation by a combination of the two measured values. The heat accumulator consists of several elements connected in parallel. A control device makes sure that only one accumulator element at a time is part of the circuit. The absorbers, as usual, consists of the absorber plate proper and a cover plate.

  16. Characterization of microstructural strengthening in the heat-affected zone of a blast-resistant naval steel

    Energy Technology Data Exchange (ETDEWEB)

    Yu Xinghua, E-mail: yu.345@osu.edu [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43221 (United States); Caron, Jeremy L. [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43221 (United States)] [Welding and Joining Metallurgy Group, Welding Engineering Program, 1248 Arthur E. Adams Drive, Ohio State University, Columbus, OH 43221 (United States); Babu, S.S., E-mail: babu.13@osu.edu [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43221 (United States) and Welding and Joining Metallurgy Group, Welding Engineering Program, 1248 Arthur E. Adams Drive, Ohio State University, Columbus, OH 43221 (United States); Lippold, John C. [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43221 (United States)] [Welding and Joining Metallurgy Group, Welding Engineering Program, 1248 Arthur E. Adams Drive, Ohio State University, Columbus, OH 43221 (United States); Isheim, Dieter; Seidman, David N. [Department of Materials Science and Engineering, Northwestern University, 2220 North Campus Drive, Evanston, IL 60208 (United States)] [Northwestern University Center for Atom-Probe Tomography, 2220 North Campus Drive, Evanston, IL 60208 (United States)

    2010-10-15

    The influence of simulated heat-affected zone thermal cycles on the microstructural evolution in a blast-resistant naval steel was investigated by dilatometry, microhardness testing, optical microscopy, electron backscatter diffraction and atom-probe tomography (APT) techniques. Coarsening of Cu precipitates were observed in the subcritical and intercritical heat-affected zones, with partial dissolution in the latter. A small number density of Cu precipitates and high Cu concentration in the matrix of the fine-grained heat-affected zone indicates the onset of Cu precipitate dissolution. Cu clustering in the coarse-grained heat-affected zone indicated the potential initiation of Cu reprecipitation during cooling. Segregation of Cu was also characterized by APT. The hardening and softening observed in the heat-affected zone regions was rationalized using available strengthening models.

  17. Various methods to improve heat transfer in exchangers

    Directory of Open Access Journals (Sweden)

    Pavel Zitek

    2015-01-01

    Full Text Available The University of West Bohemia in Pilsen (Department of Power System Engineering is working on the selection of effective heat exchangers. Conventional shell and tube heat exchangers use simple segmental baffles. It can be replaced by helical baffles, which increase the heat transfer efficiency and reduce pressure losses. Their usage is demonstrated in the primary circuit of IV. generation MSR (Molten Salt Reactors. For high-temperature reactors we consider the use of compact desk heat exchangers, which are small, which allows the integral configuration of reactor. We design them from graphite composites, which allow up to 1000°C and are usable as exchangers: salt-salt or salt-acid (e.g. for the hydrogen production. In the paper there are shown thermo-physical properties of salts, material properties and principles of calculations.

  18. Method for removal of decay heat of radioactive substances

    International Nuclear Information System (INIS)

    Hesky, H.; Wunderer, A.

    1981-01-01

    In this process, the decay heat from radioactive substances is removed by means of a liquid carried in the coolant loop. The liquid is partially evaporated by the decay heat. The steam is used to drive the liquid through the loop. When a static pressure level equivalent to the pressure drop in the loop is exceeded, the steam is separated from the liquid, condensed, and the condensate is reunited with the return flow of liquid for partial evaporation. (orig.) [de

  19. Scale Resistant Heat Exchanger for Low Temperature Geothermal Binary Cycle Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hays, Lance G. [Energent Corporation, Santa Ana, CA (United States)

    2014-11-18

    Phase 1 of the investigation of improvements to low temperature geothermal power systems was completed. The improvements considered were reduction of scaling in heat exchangers and a hermetic turbine generator (eliminating seals, seal system, gearbox, and lube oil system). A scaling test system with several experiments was designed and operated at Coso geothermal resource with brine having a high scaling potential. Several methods were investigated at the brine temperature of 235 ºF. One method, circulation of abradable balls through the brine passages, was found to substantially reduce scale deposits. The test heat exchanger was operated with brine outlet temperatures as low as 125 ºF, which enables increased heat input available to power conversion systems. For advanced low temperature cycles, such as the Variable Phase Cycle (VPC) or Kalina Cycle, the lower brine temperature will result in a 20-30% increase in power production from low temperature resources. A preliminary design of an abradable ball system (ABS) was done for the heat exchanger of the 1 megawatt VPC system at Coso resource. The ABS will be installed and demonstrated in Phase 2 of this project, increasing the power production above that possible with the present 175 ºF brine outlet limit. A hermetic turbine generator (TGH) was designed and manufacturing drawings produced. This unit will use the working fluid (R134a) to lubricate the bearings and cool the generator. The 200 kW turbine directly drives the generator, eliminating a gearbox and lube oil system. Elimination of external seals eliminates the potential of leakage of the refrigerant or hydrocarbon working fluids, resulting in environmental improvement. A similar design has been demonstrated by Energent in an ORC waste heat recovery system. The existing VPC power plant at Coso was modified to enable the “piggyback” demonstration of the TGH. The existing heat exchanger, pumps, and condenser will be operated to provide the required

  20. Calculation methods for SPF for heat pump systems for comparison, system choice and dimensioning

    Energy Technology Data Exchange (ETDEWEB)

    Nordman, Roger; Andersson, Kajsa; Axell, Monica; Lindahl, Markus

    2010-09-15

    In this project, results from field measurements of heat pumps have been collected and summarised. Also existing calculation methods have been compared and summarised. Analyses have been made on how the field measurements compare to existing calculation models for heat pumps Seasonal Performance Factor (SPF), and what deviations may depend on. Recommendations for new calculation models are proposed, which include combined systems (e.g. solar - HP), capacity controlled heat pumps and combined DHW and heating operation

  1. Critical heat flux detection in rods simulating fuel elements by using dilation method

    International Nuclear Information System (INIS)

    Mesquita, A.Z.

    1993-01-01

    In out-reactor heat transfer experiments, fuel elements are often simulated by electrically heated rods. In order to prevent the heating rod from being damaged by burnout, when the critical heat flux occurs a safety system is provided which checks the axial thermal expansion of the rod. In case of sudden temperature increase, the corresponding elongation causes a fast interruption of the electrical power supply. The experiments presented here show that this method is more effective than one that uses thermocouples. (author)

  2. Progress towards RF heated steady-state plasma operations on LHD by employing ICRF heating methods and improved divertor plates

    International Nuclear Information System (INIS)

    Kumazawa, R.; Mutoh, T.; Saito, K.

    2008-10-01

    A long pulse plasma discharge experiment was carried out using RF heating power in the Large Helical Device (LHD), a currentless magnetic confining system. Progress in long pulse operation is summarized since the 10th experimental campaign (2006). A scaling relation of the plasma duration time to the applied RF power has been derived from the experimental data so far collected. It indicates that there exists a critical divertor temperature and consequently a critical RF heating power P RFcrit =0.65 MW. The area on the graph of the duration time versus the RF heating power was extended over the scaling relation by replacing divertor plates with new ones with better heat conductivity. The cause of the plasma collapse at the end of the long pulse operation was found to be the penetration of metal impurities. Many thin flakes consisting of heavy metals and graphite in stratified layers were found on the divertor plates and it was thought that they were the cause of impurity metals penetrating into the plasma. In a simulation involving injecting a graphite-coated Fe pellet to the plasma it was found that 230 Eμm in the diameter of the Fe pellet sphere was the critical size which led the plasma to collapse. A mode-conversion heating method was examined in place of the minority ICRF heating which has been employed in almost all the long-pulse plasma discharges. It was found that this method was much better from the viewpoint of achieving uniformity of the plasma heat load to the divertors. It is expected that P RFcrit will be increased by using the mode-conversion heating method. (author)

  3. Research on Comprehensive Evaluation Method for Heating Project Based on Analytic Hierarchy Processing

    Science.gov (United States)

    Han, Shenchao; Yang, Yanchun; Liu, Yude; Zhang, Peng; Li, Siwei

    2018-01-01

    It is effective to reduce haze in winter by changing the distributed heat supply system. Thus, the studies on comprehensive index system and scientific evaluation method of distributed heat supply project are essential. Firstly, research the influence factors of heating modes, and an index system with multiple dimension including economic, environmental, risk and flexibility was built and all indexes were quantified. Secondly, a comprehensive evaluation method based on AHP was put forward to analyze the proposed multiple and comprehensive index system. Lastly, the case study suggested that supplying heat with electricity has great advantage and promotional value. The comprehensive index system of distributed heating supply project and evaluation method in this paper can evaluate distributed heat supply project effectively and provide scientific support for choosing the distributed heating project.

  4. Farmers’ Perceptions and Knowledge of Cattle Adaptation to Heat Stress and Tick Resistance in the Eastern Cape, South Africa

    Directory of Open Access Journals (Sweden)

    C. L. F. Katiyatiya

    2014-11-01

    Full Text Available The objective of this study was to determine the perceptions and knowledge of farmers of heat stress and tick resistance in cattle. A cross-sectional survey was conducted and 110 farmers in four villages in the sour and sweet velds of the Eastern Cape Province, South Africa were interviewed. The associations among area (municipality, gender, age, level of education, employment and religion were computed using Chi-square tests. The majority of the respondents had on average 4 bulls, 4 cows, 4 heifers, 4 calves, and 4 oxen. Milk was considered as the major (28.3% reason for keeping cattle. Most farmers owned non-descript (72.6%, and Nguni (45.3% cattle because of their heat tolerance (54.7%, tick resistance (54.7%, and milking ability (28.2% traits. Excessive panting (56.6% and disease transmission (76% were regarded as the major effects of heat stress and tick infestation in cattle, respectively. About 50% of the respondents agreed that hair length influences tick resistance and 47.17% considered coat colour when acquiring cattle. In the sampled areas, ticks were prevalent in the summer season (93%, and 77.36% of the respondents use acaricides every fortnight. Gall sickness was reported to be a major problem in the cattle herds by 36.79% of the respondents. Our results showed that farmers in the two municipalities had knowledge of cattle adaptation to heat stress and tick resistance.

  5. Physiological quality and gene expression related to heat-resistant proteins at different stages of development of maize seeds.

    Science.gov (United States)

    Andrade, T; Von Pinho, E V R; Von Pinho, R G; Oliveira, G E; Andrade, V; Fernandes, J S

    2013-09-13

    We quantified and characterized the expression of heat-resistant proteins during seed development of maize lines with distinct levels of tolerance to high drying temperature. A corn field was planted for multiplication of seeds of different lines, two tolerant and two non-tolerant to high drying temperatures. Harvest of the seeds was carried out at various stages of development and they were then subjected to tests of moisture content, germination, first count of germination, accelerated aging, and cold test. The seeds were stored in a freezer for later analysis of expression of heat-resistant proteins by means of real-time PCR, electrophoresis, and spectrophotometry. We observed that heat-resistant proteins are expressed in a differential manner in seeds from different lines and at different stages of development. The expression of heat-resistant proteins was earlier in lines tolerant to high drying temperatures. Greater germination and vigor values was found for seeds collected at the last stage of development.

  6. Sporulation environment of emetic toxin-producing Bacillus cereus strains determines spore size, heat resistance and germination capacity

    NARCIS (Netherlands)

    Voort, van der M.; Abee, T.

    2013-01-01

    Aim Heat resistance, germination and outgrowth capacity of Bacillus cereus spores in processed foods are major factors in causing the emetic type of gastrointestinal disease. In this study, we aim to identify the impact of different sporulation conditions on spore properties of emetic

  7. Integral methods of solving boundary-value problems of nonstationary heat conduction and their comparative analysis

    Science.gov (United States)

    Kot, V. A.

    2017-11-01

    The modern state of approximate integral methods used in applications, where the processes of heat conduction and heat and mass transfer are of first importance, is considered. Integral methods have found a wide utility in different fields of knowledge: problems of heat conduction with different heat-exchange conditions, simulation of thermal protection, Stefantype problems, microwave heating of a substance, problems on a boundary layer, simulation of a fluid flow in a channel, thermal explosion, laser and plasma treatment of materials, simulation of the formation and melting of ice, inverse heat problems, temperature and thermal definition of nanoparticles and nanoliquids, and others. Moreover, polynomial solutions are of interest because the determination of a temperature (concentration) field is an intermediate stage in the mathematical description of any other process. The following main methods were investigated on the basis of the error norms: the Tsoi and Postol’nik methods, the method of integral relations, the Gudman integral method of heat balance, the improved Volkov integral method, the matched integral method, the modified Hristov method, the Mayer integral method, the Kudinov method of additional boundary conditions, the Fedorov boundary method, the method of weighted temperature function, the integral method of boundary characteristics. It was established that the two last-mentioned methods are characterized by high convergence and frequently give solutions whose accuracy is not worse that the accuracy of numerical solutions.

  8. Effects of the Solid Solution Heat Treatment on the Corrosion Resistance Property of SSC13 Cast Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kuk-Jin [Hi-Sten Co., Ltd., Gimhae (Korea, Republic of); Lim, Su Gun [Gyeongsang National University, Jinju (Korea, Republic of); Pak, S. J. [Gachon BioNano Research Institute, Gachon University, Sungnam (Korea, Republic of)

    2015-04-15

    Recently, Stainless steels have been increasingly selected as the fitting or the valve materials of water pipes as the human health issue is getting higher and higher. Therefore, the connectors attached at pipes to deliver water are exposed to more severe environments than the pipes because crevice or galvanic corrosion is apt to occur at the fittings or the valves. Effects of the solid solution annealing, cooling rate after this heat treatment, and passivation on the corrosion properties of the shell mold casted SSC13 (STS304 alloy equivalent) were studied. The heating and quenching treatment more or less reduced hardness but effectively improved corrosion resistance. It was explained by the reduction of delta ferrite contents. Independent of heat treatment, the chemical passivation treatment also lowered corrosion rate but the improvement of corrosion resistance depended on temperature and time for passivation treatment indicating that the optimum conditions for passivation treatment were the bath temperature of 34 .deg. C and operating time of 10 minutes. Therefore it is suggested that the corrosion resistance of SSC13 can be effectively improved with the heat treatment, where SSC13 is heated for 10 minutes at 1120 °C and quenched and passivation treatment, where SSC13 is passivated for at least 10 seconds at 34 °C nitric acid solution.

  9. Formulation of stable Bacillus subtilis AH18 against temperature fluctuation with highly heat-resistant endospores and micropore inorganic carriers.

    Science.gov (United States)

    Chung, Soohee; Lim, Hyung Mi; Kim, Sang-Dal

    2007-08-01

    To survive the commercial market and to achieve the desired effect of beneficial organisms, the strains in microbial products must be cost-effectively formulated to remain dormant and hence survive through high and low temperatures of the environment during transportation and storage. Dormancy and stability of Bacillus subtilis AH18 was achieved by producing endospores with enhanced heat resistance and using inorganic carriers. Heat stability assays, at 90 degrees C for 1 h, showed that spores produced under a sublethal temperature of 57 degrees C was 100 times more heat-resistant than the ones produced by food depletion at the growing temperature of 37 degrees C. When these highly heat-resistant endospores were formulated with inorganic carriers of natural and synthetic zeolite or kaolin clay minerals having substantial amount of micropores, the dormancy of the endospores was maintained for 6 months at 15-25 degrees C. Meanwhile, macroporous perlite carriers with average pore diameter larger than 3.7 microm stimulated the germination of the spores and rapid proliferation of the bacteria. These results indicated that a B. subtilis AH18 product that can remain dormant and survive through environmental temperature fluctuation can be formulated by producing heat-stressed endospores and incorporating inorganic carriers with micropores in the formulation step.

  10. Experimental study on method for heat transfer enhancement using a porous material

    International Nuclear Information System (INIS)

    Shimura, Takuya; Takeda, Tetsuaki

    2011-01-01

    There are several methods for enhancement of heat transfer; for example, there are attaching various fins on the heat transfer surface, processing the surface roughly, and so on. When cooling high temperature circular or rectangular channels by forced convection of gas, there are several methods for enhancement of heat transfer such as attaching radial or spiral fins on the channel surface or inserting twisted tape in the channel. In the case of the gas heating type steam reformer, disk type fins are attached on the outside surface of the reformer tube, and the tube is inserted into the guide tube to increase an amount of heat transferred from the high temperature gas. However, it has to take into consideration the deterioration of the structure strength by attaching the fins on the tube surface with the design of the steam reformer. The objective of this study is to clarify performances of a method for heat transfer enhancement using porous material with high porosity. The experiment has been performed using an apparatus which simulated the passage structure of the steam reformer to obtain characteristics of heat transfer and pressure drop. From the results obtained in this experiment, the heat transfer rate by this method showed a good performance in the laminar flow region. It was also found that the method for heat transfer enhancement using porous material with high porosity is further improved under the high temperature condition as compared with the other methods for heat transfer enhancement. (author)

  11. Extreme Heat Resistance of Food Borne Pathogens Campylobacter jejuni, Escherichia coli, and Salmonella typhimurium on Chicken Breast Fillet during Cooking

    Directory of Open Access Journals (Sweden)

    Aarieke E.I. de Jong

    2012-01-01

    The surface temperature reached 70∘C within 30 sec and 85∘C within one minute. Extremely high decimal reduction times of 1.90, 1.97, and 2.20 min were obtained for C. jejuni, E. coli, and S. typhimurium, respectively. Chicken meat and refrigerated storage before cooking enlarged the heat resistance of the food borne pathogens. Additionally, a high challenge temperature or fast heating rate contributed to the level of heat resistance. The data were used to assess the probability of illness (campylobacteriosis due to consumption of chicken fillet as a function of cooking time. The data revealed that cooking time may be far more critical than previously assumed.

  12. Comparative proteomic and metabolomic profiling of citrus fruit with enhancement of disease resistance by postharvest heat treatment.

    Science.gov (United States)

    Yun, Ze; Gao, Huijun; Liu, Ping; Liu, Shuzhen; Luo, Tao; Jin, Shuai; Xu, Qiang; Xu, Juan; Cheng, Yunjiang; Deng, Xiuxin

    2013-03-16

    From field harvest to the consumer's table, fresh citrus fruit spends a considerable amount of time in shipment and storage. During these processes, physiological disorders and pathological diseases are the main causes of fruit loss. Heat treatment (HT) has been widely used to maintain fruit quality during postharvest storage; however, limited molecular information related to this treatment is currently available at a systemic biological level. Mature 'Kamei' Satsuma mandarin (Citrus unshiu Marc.) fruits were selected for exploring the disease resistance mechanisms induced by HT during postharvest storage. Proteomic analyses based on two-dimensional gel electrophoresis (2-DE), and metabolomic research based on gas chromatography coupled to mass spectrometry (GC-MS), and liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF-MS) were conducted. The results show resistance associated proteins were up-regulated in heat treated pericarp, such as beta-1, 3-glucanase, Class III chitinase, 17.7 kDa heat shock protein and low molecular weight heat-shock protein. Also, redox metabolism enzymes were down-regulated in heat treated pericarp, including isoflavone reductase, oxidoreductase and superoxide dismutase. Primary metabolic profiling revealed organic acids and amino acids were down-regulated in heat treated pericarp; but significant accumulation of metabolites, including tetradecanoic acid, oleic acid, ornithine, 2-keto-d-gluconic acid, succinic acid, turanose, sucrose, galactose, myo-inositol, glucose and fructose were detected. Noticeably, H2O2 content decreased, while, lignin content increased in heat treated pericarp compared to the control, which might increase fruit resistibility in response to external stress. Also, flavonoids, substances which are well-known to be effective in reducing external stress, were up-regulated in heat treated pericarp. This study provides a broad picture of differential accumulation of proteins and metabolites in

  13. Laws of alloyed cementite particles nucleation during heat-resistant steels carburizing

    Directory of Open Access Journals (Sweden)

    M. Yu. Semenov

    2014-01-01

    Full Text Available The article considers a problem analyzing a nucleation of cementite type carbides in carburized heat-resistant steels for the turbofan engines gear wheels.The verification of previously hypothesized mechanism of dislocation nucleation particles chromium-alloyed cementite during process of carburizing was accepted as an objective of the work.As a methodological basis of this paper were accepted the numerical experiments based on the kinetic theory of nucleation, as well as on the known results of experimental studies.According to the kinetic theory of nucleation, a new phase in the solid solutions take place in the defects of the crystal structure of the metal such as inter-grain boundaries and dislocations clusters. A principle feature of the inter-grain boundary mechanism of nucleation is formation of carbide lattice. It is of great practical interest because the cementite lattice drops mechanical properties of hardened parts.According to the experimental studies, the average chromium concentration in the alloyed cementite twice exceeds its Cr content in the heat-resistant steels. Furthermore, the areas of abnormally high (more than ten times in comparison with the average content chromium concentration in cementite have been experimentally revealed.Numerical experiments have revealed that the nucleation of cementite particles alloyed with chromium (chromium concentration of 3% or more occurs, mainly, by the dislocation mechanism on the concentration fluctuations of the alloying element. According to calculations, an obligatory prerequisite to start an active nucleation process of new phase in the solid solution is a local increase of the chromium concentration up to 40%.Despite the lack of physical prerequisites for the formation of chromium precipitates, this phenomenon is explained by a strong chemical affinity of chromium and carbon, causing diffusion of chromium atoms in the region of the carbon atoms clusters. The formation of carbon

  14. A method to study electron heating during ICRH

    International Nuclear Information System (INIS)

    Eriksson, L.G.; Hellsten, T.

    1989-01-01

    Collisionless absorption of ICRF waves occurs either by ion cyclotron absorption or by electron Landau (ELD) and transit damping (TTMP). Both ion cyclotron absorption, and direct electron absorption results in electron heating. Electron heating by minority ions occurs after a high energy tail of the resonating ions has been formed i.e. typically after 0.2-1s in present JET experiments. Electron heating through ELD, and TTMP, takes place on the timescale given by electron-electron collisions which is typically of the order of ms. This difference in the timescales can be used to separate the two damping mechanisms. This can be done by measuring the time derivatives of the electron temperature after sawtooth crashes during ramp-up and ramp-down of the RF-power. (author) 4 refs., 4 figs

  15. Application of Electrical Resistivity Method (ERM) in Groundwater Exploration

    Science.gov (United States)

    Izzaty Riwayat, Akhtar; Nazri, Mohd Ariff Ahmad; Hazreek Zainal Abidin, Mohd

    2018-04-01

    The geophysical method which dominant by geophysicists become one of most popular method applied by engineers in civil engineering fields. Electrical Resistivity Method (ERM) is one of geophysical tool that offer very attractive technique for subsurface profile characterization in larger area. Applicable alternative technique in groundwater exploration such as ERM which complement with existing conventional method may produce comprehensive and convincing output thus effective in terms of cost, time, data coverage and sustainable. ERM has been applied by various application in groundwater exploration. Over the years, conventional method such as excavation and test boring are the tools used to obtain information of earth layer especially during site investigation. There are several problems regarding the application of conventional technique as it only provides information at actual drilling point only. This review paper was carried out to expose the application of ERM in groundwater exploration. Results from ERM could be additional information to respective expert for their problem solving such as the information on groundwater pollution, leachate, underground and source of water supply.

  16. Advanced Computational Methods for Thermal Radiative Heat Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Tencer, John; Carlberg, Kevin Thomas; Larsen, Marvin E.; Hogan, Roy E.,

    2016-10-01

    Participating media radiation (PMR) in weapon safety calculations for abnormal thermal environments are too costly to do routinely. This cost may be s ubstantially reduced by applying reduced order modeling (ROM) techniques. The application of ROM to PMR is a new and unique approach for this class of problems. This approach was investigated by the authors and shown to provide significant reductions in the computational expense associated with typical PMR simulations. Once this technology is migrated into production heat transfer analysis codes this capability will enable the routine use of PMR heat transfer in higher - fidelity simulations of weapon resp onse in fire environments.

  17. ELECTRICAL RESISTANCE HEATING OF SOILS AT C-REACTOR AT THE SAVANNAH RIVER SITE

    International Nuclear Information System (INIS)

    Blundy, R; Michael Morgenstern, M; Joseph Amari, J; Annamarie MacMurray, A; Mark Farrar, M; Terry Killeen, T

    2007-01-01

    Chlorinated solvent contamination of soils and groundwater is an endemic problem at the Savannah River Site (SRS), and originated as by-products from the nuclear materials manufacturing process. Five nuclear reactors at the SRS produced special nuclear materials for the nation's defense program throughout the cold war era. An important step in the process was thorough degreasing of the fuel and target assemblies prior to irradiation. Discharges from this degreasing process resulted in significant groundwater contamination that would continue well into the future unless a soil remediation action was performed. The largest reactor contamination plume originated from C-Reactor and an interim action was selected in 2004 to remove the residual trichloroethylene (TCE) source material by electrical resistance heating (ERH) technology. This would be followed by monitoring to determine the rate of decrease in concentration in the contaminant plume. Because of the existence of numerous chlorinated solvent sources around SRS, it was elected to generate in-house expertise in the design and operation of ERH, together with the construction of a portable ERH/SVE system that could be deployed at multiple locations around the site. This paper describes the waste unit characteristics, the ERH system design and operation, together with extensive data accumulated from the first deployment adjacent to the C-Reactor building. The installation heated the vadose zone down to 62 feet bgs over a 60 day period during the summer of 2006 and raised soil temperatures to over 200 F. A total of 730 lbs of trichloroethylene (TCE) were removed over this period, and subsequent sampling indicated a removal efficiency of 99.4%

  18. Effect of oxide film of heat resistant alloy on coke formation during naphtha pyrolysis

    International Nuclear Information System (INIS)

    Shiratori, Nobuo; Hosoya, Keizo

    2002-01-01

    The coking of cracking furnace tubes has been an important subject of ethylene plants. The coke formations rate on the heat resistant alloys of 20Cr-4.5Al-0.5Y 2 O 3 covered with Al 2 O 3 oxide film and 25Cr-35Ni covered with Cr 2 O 3 oxide film during the thermal cracking of naphtha was quantitatively evaluated at temperatures ranging from 810 to 930 .deg. C. The experimental results showed that the coke formation rate on 20Cr-4.5Al-0.5Y 2 O 3 was lower than that on 25Cr-35Ni because of the difference of a catalytic activity to coke formation, especially in the case of a pre-carburized condition. Namely, the Al 2 O 3 formed on 20Cr-4.5Al-0.5Y 2 O 3 was stable even after carburization treatment and inert for catalytic coke formation, while coke formation on 25Cr-35Ni was under the control of catalytic coke formation, and carburization of 25Cr-35Ni accelerated catalytic coke formation. The stability of Al 2 O 3 and Cr 2 O 3 in a hydrocarbon with steam environment was thermodynamically calculated in 0.1mol of steam, 0.2mol of ethylene and 0.1mol of methane at 1,100 .deg. C. The simulation result shows that Al 2 O 3 is exceedingly stable while Cr 2 O 3 could be decomposed partially into chromium carbide. Therefore, it is concluded that Al 2 O 3 on 20Cr-4.5Al-0.5Y 2 O 3 is more stable than Cr 2 O 3 on 25Cr-35Ni, and 20Cr-4.5Al-0.5Y 2 O 3 is more resistant to coke formation and carburization than 25Cr-35Ni in a hydrocarbon with steam environment at high temperature

  19. Determination of the thermal conductivity and specific heat capacity of neem seeds by inverse problem method

    Directory of Open Access Journals (Sweden)

    S.N. Nnamchi

    2010-01-01

    Full Text Available Determination of the thermal conductivity and the specific heat capacity of neem seeds (Azadirachta indica A. Juss usingthe inverse method is the main subject of this work. One-dimensional formulation of heat conduction problem in a spherewas used. Finite difference method was adopted for the solution of the heat conduction problem. The thermal conductivityand the specific heat capacity were determined by least square method in conjunction with Levenberg-Marquardt algorithm.The results obtained compare favourably with those obtained experimentally. These results are useful in the analysis ofneem seeds drying and leaching processes.

  20. Method for calculating thermal properties of lightweight floor heating panels based on an experimental setup

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Svendsen, Svend

    2005-01-01

    , radiation and conduction of the heat transfer between pipe and surrounding materials. The European Standard for floor heating, EN1264, does not cover lightweight systems, while the supplemental Nordtest Method VVS127 is aimed at lightweight systems. The thermal properties can be found using tabulated values...... simulation model. It has been shown that the method is accurate with an error on the heat fluxes of less than 5% for different supply temperatures. An error of around 5% is also recorded when comparing measurements to calculated heat flows using the Nordtest VVS 127 method based on the experimental setup...

  1. Kinetic and Mechanism Study of Vanadium Acid Leaching from Black Shale Using Microwave Heating Method

    Science.gov (United States)

    Wang, Jing-peng; Zhang, Yi-min; Huang, Jing; Liu, Tao

    2018-06-01

    The leaching kinetics of the vanadium leaching process were investigated by the comparison of microwave heating and conventional heating methods. Microwave heating with CaF2 had a synergistic effect and improved the vanadium leaching efficiency. In contrast to conventional heating leaching, microwave heating accelerated the vanadium leaching rate by approximately 1-3% and by approximately 15% when CaF2 was also used. The kinetics analysis showed that the calculated activation energy decreased in the microwave heating method in the presence and absence of CaF2. The control procedure of leaching also changed from a chemical reaction control step to a mixed chemical diffusion control step upon the addition of CaF2. Microwave heating was shown to be suitable for leaching systems with diffusion or mixed chemical diffusion control steps when the target mineral does not have a microwave absorbing ability.

  2. Kinetic and Mechanism Study of Vanadium Acid Leaching from Black Shale Using Microwave Heating Method

    Science.gov (United States)

    Wang, Jing-peng; Zhang, Yi-min; Huang, Jing; Liu, Tao

    2018-04-01

    The leaching kinetics of the vanadium leaching process were investigated by the comparison of microwave heating and conventional heating methods. Microwave heating with CaF2 had a synergistic effect and improved the vanadium leaching efficiency. In contrast to conventional heating leaching, microwave heating accelerated the vanadium leaching rate by approximately 1-3% and by approximately 15% when CaF2 was also used. The kinetics analysis showed that the calculated activation energy decreased in the microwave heating method in the presence and absence of CaF2. The control procedure of leaching also changed from a chemical reaction control step to a mixed chemical diffusion control step upon the addition of CaF2. Microwave heating was shown to be suitable for leaching systems with diffusion or mixed chemical diffusion control steps when the target mineral does not have a microwave absorbing ability.

  3. Influence of heating rates on in situ resistance measurements of a bronze route Nb-Sn-Cu-Ta multifilamentary conductor

    International Nuclear Information System (INIS)

    Tan, K.S.; Hopkins, S.C.; Glowacki, B.A.

    2004-01-01

    The superconducting properties of a bronze process multifilamentary conductor are controlled by the structure, dimensions and composition of the intermetallic layers, which are strongly influenced by the details of the heat treatments applied to the conductor. It has previously been reported that the electrical resistivity of a Vacuumschmelze bronze process conductor varies during heat treatment, and that analysis of the conductor as a set of parallel resistors allows the features of the resistivity variation to be assigned to the progress of Nb 3 Sn intermetallic phase formation. The behaviour of NSP2 Nb-Sn-Cu-Ta bronze process multifilamentary conductors (Imperial Metal Industries) is now reported as a function of the heating rate, in preparation for more complex non-isothermal heat treatment procedures. It is shown that the resistance of the wire measured in situ by an alternating current (AC) technique can be used to observe the progress of the formation of Nb 3 Sn, and that the comparison of resistometric measurements at different heating rates can give an indication of other processes (such as recovery and recrystallisation) occurring at lower temperatures during the heating up process prior to isothermal annealing. In addition, this wire containing only about 1% of copper was carefully chosen because of the broken tantalum barriers around individual copper filaments. Therefore, the resistometric measurements were used to attempt to detect the diffusion of tin from the bronze matrix into the copper filaments at lower temperatures without noticeable influence on Nb 3 Sn phase formation. Treating the NSP2 wire as a set of parallel resistors also permits estimates to be made of the intermetallic layer thicknesses from resistometric measurements, and these are shown to be in good agreement with estimates from scanning electron microscopy. The difference in critical temperature, T c , between wires heated at different rates, with the presence of the bronze matrix

  4. Insight into the heat resistance of fish via blood: Effects of heat stress on metabolism, oxidative stress and antioxidant response of olive flounder Paralichthys olivaceus and turbot Scophthalmus maximus.

    Science.gov (United States)

    Lu, Yunliang; Wu, Zhihao; Song, Zongcheng; Xiao, Peng; Liu, Ying; Zhang, Peijun; You, Feng

    2016-11-01

    High temperature has direct confinement on fish survival and growth, especially under the background of global warming. Selection of fish line with heat resistance is an important means to address this problem. In the present study, we analyzed the difference in heat resistance between families of olive flounder Paralichthys olivaceus and turbot Scophthalmus maximus, two flatfish species occupying slightly different thermal niches. Then the chosen families were tested to determine their differential response to heat stress (ΔT = +8 °C and +12 °C) in blood, including anaerobic metabolism (lactate), oxidative stress (lipid peroxidation and protein carbonylation) and antioxidant enzymes. Results showed a difference in heat resistance between families of the two species. Among the chosen parameters, growth traits had a significant effect on contents of lactate and malondialdehyd (MDA), and activities of catalase (CAT) and glutathione S-transferase in flounder (P heat-sensitive family of each species, levels of all studied parameters were lower and more stable in heat-resistant families after heat stress. What's more, heat resistance of fish significantly influenced contents of lactate and MDA and activity of CAT in flounder (P heat-resistance, being potentially valuable in fish breeding. However, these markers should be applied with more caution when there is a growth discrepancy between fish families. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Incorporating Water Boiling in the Numerical Modelling of Thermal Remediation by Electrical Resistance Heating

    Science.gov (United States)

    Molnar, I. L.; Krol, M.; Mumford, K. G.

    2017-12-01

    Developing numerical models for subsurface thermal remediation techniques - such as Electrical Resistive Heating (ERH) - that include multiphase processes such as in-situ water boiling, gas production and recovery has remained a significant challenge. These subsurface gas generation and recovery processes are driven by physical phenomena such as discrete and unstable gas (bubble) flow as well as water-gas phase mass transfer rates during bubble flow. Traditional approaches to multiphase flow modeling soil remain unable to accurately describe these phenomena. However, it has been demonstrated that Macroscopic Invasion Percolation (MIP) can successfully simulate discrete and unstable gas transport1. This has lead to the development of a coupled Electro Thermal-MIP Model2 (ET-MIP) capable of simulating multiple key processes in the thermal remediation and gas recovery process including: electrical heating of soil and groundwater, water flow, geological heterogeneity, heating-induced buoyant flow, water boiling, gas bubble generation and mobilization, contaminant mass transport and removal, and additional mechanisms such as bubble collapse in cooler regions. This study presents the first rigorous validation of a coupled ET-MIP model against two-dimensional water boiling and water/NAPL co-boiling experiments3. Once validated, the model was used to explore the impact of water and co-boiling events and subsequent gas generation and mobilization on ERH's ability to 1) generate, expand and mobilize gas at boiling and NAPL co-boiling temperatures, 2) efficiently strip contaminants from soil during both boiling and co-boiling. In addition, a quantification of the energy losses arising from steam generation during subsurface water boiling was examined with respect to its impact on the efficacy of thermal remediation. While this study specifically targets ERH, the study's focus on examining the fundamental mechanisms driving thermal remediation (e.g., water boiling) renders

  6. Methods of driving current by heating a toroidal plasma

    International Nuclear Information System (INIS)

    Fisch, N.J.

    1980-08-01

    In addition to the usual mechanism which utilizes the Ohmic transformer current, which is necessarily pulsed, there exist several steady-state mechanisms. Heating mechanisms which can lend themselves efficiently to continuous current generation include neutral beams, Alfven waves, ion-cyclotron waves, lower-hybrid waves and electron-cyclotron waves

  7. Case Studies in Low-Energy District Heating Systems: Determination of Dimensioning Methods for Planning the Future Heating Infrastructure

    DEFF Research Database (Denmark)

    Tol, Hakan; Nielsen, Susanne Balslev; Svendsen, Svend

    suggests a plan for an energy efficient District Heating (DH) system with low operating temperatures, such as 55°C supply and 25°C return; connected to low-energy buildings. Different case studies referring to typical DH planning situations could show the rational basis for the integrated planning...... of the future’s sustainable and energy efficient heating infrastructure. In this paper, a case study which focuses on dimensioning method of piping network of low-energy DH system in a new settlement, located in Roskilde Municipality, Denmark, is presented. In addition to the developed dimensioning method......, results about the optimal network layout and substation type for low-energy DH systems are also pointed out regarding to this case study. A second case study, included in this paper, focuses on technical and economical aspects of replacing natural gas heating system to low-energy DH system in an existing...

  8. Geophysical methods in protected environments. Electrical resistivity tomography

    International Nuclear Information System (INIS)

    Rubio Sánchez-Aguililla, F.M.; Ramiro-Camacho, A.; Ibarra Torre, P.

    2017-01-01

    There is a strong interest in protecting the environment with the aim of its long term preservation. Sometimes the heritage value of these natural areas is related to their biodiversity as there are restricted ecosystems that depend directly on them. In other cases there a singular geological record might exist, essential for the understanding of certain processes affecting the planet, such as volcanic events or glacial periods. To achieve the protection and conservation of these areas it is necessary to generate knowledge about the distribution of geological materials and groundwater masses, to study the parameters that dominate the behaviour of these systems and then define those elements that require special protection or attention. In these protected environments, research methods with a minimal environmental impact should be used. Therefore, indirect methods, such as geophysical techniques, are reliable and complementary tools with a minimum environmental impact and are therefore useful for research these unique areas. The IGME has conducted several geophysical surveys in different protected environments in Spain with the aim of achieving a better understanding, and thus facilitate their preservation and exploitation in a sustainable manner. In this paper we present a review of some case studies where geophysical methods have been used. In all the cases electrical resistivity tomography has been the axis of the geophysical research and stands out due to its great effectiveness. The main objective of this communication is to divulgate and increase awareness of the important role that these geophysical methods can play in the sustainable study of these unique places. [es

  9. Effect of heat treatment on microstructure, mechanical properties and erosion resistance of cast 23-8-N nitronic steel

    International Nuclear Information System (INIS)

    Kumar, Avnish; Sharma, Ashok; Goel, S.K.

    2015-01-01

    Effects of heat treatment on microstructure, mechanical properties and erosion behavior of cast 23-8-N nitronic steel were studied. A series of heat treatments were carried out in the temperature range of 1180–1240 °C to observe the effect on microstructure. Optimum heat treatment cycle was obtained at 1220 °C for holding time of 150 min, which leads to dissolution of carbides, formation of equiaxed grains and twins. Heat treatment has shown improvement in tensile strength, toughness, impact strength and work hardening capacity, however at the cost of marginal reduction in hardness and yield strength. This resulted in improvement of erosion resistance of cast 23-8-N nitronic steel. The microstructures, fractured surfaces and phases were studied by optical microscopy, field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analysis respectively

  10. Heat resistance and local structure of FeCl2-absorbed crosslinked poly(γ-glutamic acid)

    International Nuclear Information System (INIS)

    Nishida, T.; Kamezawa, H.; Hara, T.; Matsumoto, Y.

    2001-01-01

    Fiber of Japanese food natto (Bacillus subtilis) is known to be superabsorbent poly(γ-glutamic acid) (PGA). NaCl particles precipitate in FeCl 2 -absorbed crosslinked PGA when heated at crystallization temperature of 320 deg C for 10 to 60 min. After heat treatment the Moessbauer spectrum of FeCl 2 -crosslinked PGA consists of a quadrupole doublet due to FeCl 2 x 2H 2 O. The Moessbauer spectrum of anhydrous FeCl 2 reagent heated under the same condition shows an intense sextet due to α-Fe 2 O 3 . These results prove that the superabsorbent polymer, crosslinked PGA, has higher heat resistance. (author)

  11. Standard Test Method for Thermal Oxidative Resistance of Carbon Fibers

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1982-01-01

    1.1 This test method covers the apparatus and procedure for the determination of the weight loss of carbon fibers, exposed to ambient hot air, as a means of characterizing their oxidative resistance. 1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units which are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard information, see Section 8.

  12. Corrosion and wear resistant metallic layers produced by electrochemical methods

    DEFF Research Database (Denmark)

    Christoffersen, Lasse; Maahn, Ernst Emanuel

    1999-01-01

    Corrosion and wear-corrosion properties of novel nickel alloy coatings with promising production characteristics have been compared with conventional bulk materials and hard platings. Corrosion properties in neutral and acidic environments have been investigated with electrochemical methods....... Determination of polarisation resistance during 100 hours followed by stepwise anodic polarisation seems to be a promising technique to obtain steady state data on slowly corroding coatings with transient kinetics. A slurry test enables determination of simultaneous corrosion and abrasive wear. Comparison...... of AISI 316, hard chromium and hardened Ni-P shows that there is no universal correlation between surface hardness and wear-corrosion loss. The possible relation between questionable passivity of Ni-P coatings and their high wear-corrosion loss rate compared to hard chromium is discussed....

  13. Field test and sensitivity analysis of a sensible heat balance method to determine ice contents

    Science.gov (United States)

    Soil ice content impacts winter vadose zone hydrology. It may be possible to estimate changes in soil ice content with a sensible heat balance (SHB) method, using measurements from heat pulse (HP) sensors. Feasibility of the SHB method is unknown because of difficulties in measuring soil thermal pro...

  14. A Numerical Algorithm and a Graphical Method to Size a Heat Exchanger

    DEFF Research Database (Denmark)

    Berning, Torsten

    2011-01-01

    This paper describes the development of a numerical algorithm and a graphical method that can be employed in order to determine the overall heat transfer coefficient inside heat exchangers. The method is based on an energy balance and utilizes the spreadsheet application software Microsoft ExcelTM...

  15. Evaluation of the quasi-isothermal method of modulated DSC for heat capacity measurement

    International Nuclear Information System (INIS)

    Venkata Krishnan, R.; Nagarajan, K.

    2004-01-01

    Heat capacity measurements were carried out on ThO 2 by Modulated Differential Scanning Calorimetry (MDSC) using quasi-isothermal method in the temperature range 323-723 K. The highest accuracy of the heat capacity data obtained by this method was ± 2-3% which is much lower than that reported in the literature. (author)

  16. Thermal load forecasting in district heating networks using deep learning and advanced feature selection methods

    NARCIS (Netherlands)

    Suryanarayana, Gowri; Lago Garcia, J.; Geysen, Davy; Aleksiejuk, Piotr; Johansson, Christian

    2018-01-01

    Recent research has seen several forecasting methods being applied for heat load forecasting of district heating networks. This paper presents two methods that gain significant improvements compared to the previous works. First, an automated way of handling non-linear dependencies in linear

  17. A Numerical Algorithm and a Graphical Method to Size a Heat Exchanger

    DEFF Research Database (Denmark)

    Berning, Torsten

    2011-01-01

    This paper describes the development of a numerical algorithm and a graphical method that can be employed in order to determine the overall heat transfer coefficient inside heat exchangers. The method is based on an energy balance and utilizes the spreadsheet application software Microsoft Excel...

  18. Failure Mechanism of a Stellite Coating on Heat-Resistant Steel

    Science.gov (United States)

    Wang, Dong; Zhao, Haixing; Wang, Huang; Li, Yuyan; Liu, Xia; He, Guo

    2017-09-01

    The Stellite 21 coating on the heat-resistant steel X12CrMoWVNbN10-1-1 (so-called COSTE) used in a steam turbine valve was found to be fatigue broken after service at around 873 K (600 °C) for about 8 years. In order to investigate the failure mechanism, a fresh Stellite 21 coating was also prepared on the same COSTE steel substrate by using the similar deposition parameters for comparison. It was found that the Stellite 21 coating was significantly diluted by the steel, resulting in a thin Fe-rich layer in the coating close to the fusion line. Such high Fe concentration together with the incessant Fe diffusion from the steel substrate to the coating during the service condition (about 873 K (600 °C) for long time) induced the eutectoid decomposition of the fcc α-Co(Fe,Cr,Mo) solid solution, forming an irregular eutectoid microstructure that was composed of the primitive cubic α'-FeCo(Cr,Mo) phase and the tetragonal σ-CrCo(Fe,Mo) phase. The brittle nature of such α'/ σ eutectoid microstructure contributed to the fatigue fracture of the Stellite 21 coating, resulting in an intergranular rupture mode.

  19. Forced convection heat transfer in rectangular ducts: general case of wall resistances and peripheral conduction

    Energy Technology Data Exchange (ETDEWEB)

    Lyczkowski, R. W. [Institute of Gas Technology, Chicago, IL (United States); Solbrig, C. W. [Commonwealth Edison Co., Chicago, IL (United States); Gidaspow, D. [Illinois Inst. of Technology, Chicago, IL (United States)

    1980-01-01

    A numerical solution for laminar flow heat transfer between a flowing gas and its containing rectangular duct has been obtained for many different boundary conditions. The problem has been solved for the cases of insulation on no walls, one wall, two walls, and three walls with various finite resistances on the remaining walls. Results have been obtained for several duct aspect ratios in the thermal entrance and in the fully developed regions, including the constant temperature cases. When one wall is insulated and the other three are at constant temperature, the maximum temperature occurs in the fluid rather than on the insulated wall. This maximum moves toward the insulated wall with increasing axial distance. Nusselt numbers for the same constant flux on all four walls with peripheral conduction lie in a narrow band bounded by zero and infinite peripheral conduction cases. A dimensionless wall conduction group of four can be considered infinite for the purpose of estimating fully developed Nusselt numbers to within an accuracy of 3%. A decrease in wall and bulk temperatures by finite wall conduction has been demonstrated for the case of a black body radiation boundary condition.

  20. Rational thermomechanical parameters of pressing granulated heat resistant alloy-EhP741

    International Nuclear Information System (INIS)

    Garibov, G.S.; Frolov, A.A.; Ermanok, M.Z.; Kurakin, E.K.; Galkin, A.M.

    1976-01-01

    The paper deals with the development of thermomechanical parameters for the compacting of a granulated, heat-resistant, nickel-base alloy EP 741. With the flow-sheet of the technological process for the production of semi-manufactured products from granules being used as a starting point it was necessary, after compaction, to obtain a bar having optimum plastic properties and to know under what conditions these properties are to be found. On the basis of these assumptions the authors took as the optimized parameter the maximum value of the plasticity characteristic (e.g. relative to elongation of sigma) and measured it on samples cut out from a bar after compacting. The samples of granulated alloy EP 741 which were prepared from bars compacted in accordance with the plan for industrial-scale experiments were tested in factor space tsub(exp)-vsub(exp) (tsub(exp) - sample testing temperature, vsub(exp) - sample testing velocity). Using regressive analysis the authors obtained an equation describing variation of the maximum plasticity of the alloy as a function of temperature and reduction ratio. There were two repetitions of the experimental plan, at vsub(compaction) = 20 and 40mm/sec. A qualitative trend was observed in the influence of compaction velocity on the properties of the bars. The results of the final tests on extension and settling of samples cut from a compact billet showed a maximum for plastic properties at 1170-1180degC

  1. In vitro induction of variation through radiation for late blight resistance and heat tolerance in potato

    Energy Technology Data Exchange (ETDEWEB)

    Minocha, J L; Das, A; Gopal, J; Gosal, S S [Biotechnology Centre, Punjab Agricultural Univ., Ludhiana, Punjab (India)

    1997-07-01

    In vitro plants were obtained from nodal sections of sprouts of cvs. `Kufri Jyoti` and `Kufri Chandramukhi` of potato cultured on MS medium with 3% sucrose. Callus from leaves of in vitro cultured plantlets was induced on modified Linsmaier and Skoog medium supplemented with 5 mg/1 NAA. The obtained shoots and calli were irradiated with 20 and 40 Gy gamma rays. Irradiatied shoots were transferred to MS medium with 8% sucrose for multiplication, and then to MS medium with 8% sucrose and 10 mg/1 BAP to induce microtuber formation, which gave on average 1.3 microtubers per plant. The microtubers were planted in pots and variation was observed in plant morphology and tuber characters. To study variation for late blight resistance, irradiated calli were kept on Gamborg B-5 medium with culture filtrate of Phytophthora infestans. To induce variation for heat tolerance, in vitro shoots from irradiated material were mass-propagated and allowed to produce microtubers at high temperature. (author). 3 refs, 3 tabs.

  2. In vitro induction of variation through radiation for late blight resistance and heat tolerance in potato

    International Nuclear Information System (INIS)

    Minocha, J.L.; Das, A.; Gopal, J.; Gosal, S.S.

    1997-01-01

    In vitro plants were obtained from nodal sections of sprouts of cvs. 'Kufri Jyoti' and 'Kufri Chandramukhi' of potato cultured on MS medium with 3% sucrose. Callus from leaves of in vitro cultured plantlets was induced on modified Linsmaier and Skoog medium supplemented with 5 mg/1 NAA. The obtained shoots and calli were irradiated with 20 and 40 Gy gamma rays. Irradiatied shoots were transferred to MS medium with 8% sucrose for multiplication, and then to MS medium with 8% sucrose and 10 mg/1 BAP to induce microtuber formation, which gave on average 1.3 microtubers per plant. The microtubers were planted in pots and variation was observed in plant morphology and tuber characters. To study variation for late blight resistance, irradiated calli were kept on Gamborg B-5 medium with culture filtrate of Phytophthora infestans. To induce variation for heat tolerance, in vitro shoots from irradiated material were mass-propagated and allowed to produce microtubers at high temperature. (author). 3 refs, 3 tabs

  3. Resistant Starch Contents of Native and Heat-Moisture Treated Jackfruit Seed Starch

    Directory of Open Access Journals (Sweden)

    Ornanong S. Kittipongpatana

    2015-01-01

    Full Text Available Native jackfruit seed starch (JFS contains 30% w/w type II resistant starch (RS2 and can potentially be developed as a new commercial source of RS for food and pharmaceutical application. Heat-moisture treatment (HMT was explored as a mean to increase RS content of native JFS. The effect of the conditions was tested at varied moisture contents (MC, temperatures, and times. Moisture levels of 20–25%, together with temperatures 80–110°C, generally resulted in increases of RS amount. The highest amount of RS (52.2% was achieved under treatment conditions of 25% MC and 80°C, for 16 h (JF-25-80-16. FT-IR peak ratio at 1047/1022 cm−1 suggested increases in ordered structure in several HMT-JFS samples with increased RS. SEM showed no significant change in the granule appearance, except at high moisture/temperature treatment. XRD revealed no significant change in peaks intensities, suggesting the crystallinity within the granule was mostly retained. DSC showed increases in Tg and, in most cases, ΔT, as the MC was increased in the samples. Slight but significant decreases in ΔH were observed in samples with low RS, indicating that a combination of high moisture and temperature might cause partial gelatinization. HMT-JFS with higher RS exhibited less swelling, while the solubility remained mostly unchanged.

  4. A pre-heating method based on sinusoidal alternating current for lithium-ion battery

    Science.gov (United States)

    Fan, Wentao; Sun, Fengchun; Guo, Shanshan

    2018-04-01

    In this paper, a method of low temperature pre-heating of sinusoidal alternating current (SAC) is proposed. Generally, the lower the frequency of the AC current, the higher the heat generation rate. Yet at low frequency, there is a risk of lithium-ion deposition during the half cycle of charging. This study develops a temperature-adaptive, deposition-free AC pre-heating method. a equivalent electric circuit(EEC) model is established to predict the heat generation rate and temperature status, whose parameters are calibrated from the EIS impedance measurements. The effects of current frequency and amplitude on the heating effect are investigated respectively. A multistep temperature-adaptive amplitude strategy is proposed and the cell can be heated from -20°C to 5°C within 509s at 100Hz frequency with this method.

  5. An Induction Heating Method with Traveling Magnetic Field for Long Structure Metal

    Science.gov (United States)

    Sekine, Takamitsu; Tomita, Hideo; Obata, Shuji; Saito, Yukio

    A novel dismantlable adhesion method for recycling operation of interior materials is proposed. This method is applied a high frequency induction heating and a thermoplastic adhesive. For an adhesion of interior material to long steel stud, a conventional spiral coil as like IH cooking heater gives inadequateness for uniform heating to the stud. Therefore, we have proposed an induction heating method with traveling magnetic field for perfect long structures bonding. In this paper, we describe on the new adhesion method using the 20kHz, three-phase 200V inverter and linear induction coil. From induction heating characteristics to thin steel plates and long studs, the method is cleared the usefulness for uniform heating to long structures.

  6. Fluid dynamics and heat transfer methods for the TRAC code

    International Nuclear Information System (INIS)

    Reed, W.H.; Kirchner, W.L.

    1977-01-01

    A computer code called TRAC is being developed for analysis of loss-of-coolant accidents and other transients in light water reactors. This code involves a detailed, multidimensional description of two-phase flow coupled implicitly through appropriate heat transfer coefficients with a simulation of the temperature field in fuel and structural material. Because TRAC utilizes about 1000 fluid mesh cells to describe an LWR system, whereas existing lumped parameter codes typically involve fewer than 100 fluid cells, we have developed new highly implicit difference techniques that yield acceptable computing times on modern computers. Several test problems for which experimental data are available, including blowdown of single pipe and loop configurations with and without heated walls, have been computed with TRAC. Excellent agreement with experimental results has been obtained. (author)

  7. Fluid dynamics and heat transfer methods for the TRAC code

    International Nuclear Information System (INIS)

    Reed, W.H.; Kirchner, W.L.

    1977-01-01

    A computer code called TRAC is being developed for analysis of loss-of-coolant accidents and other transients in light water reactors. This code involves a detailed, multidimensional description of two-phase flow coupled implicitly through appropriate heat transfer coefficients with a simulation of the temperature field in fuel and structural material. Because TRAC utilizes about 1000 fluid mesh cells to describe an LWR system, whereas existing lumped parameter codes typically involve fewer than 100 fluid cells, new highly implicit difference techniques are developed that yield acceptable computing times on modern computers. Several test problems for which experimental data are available, including blowdown of single pipe and loop configurations with and without heated walls, have been computed with TRAC. Excellent agreement with experimental results has been obtained

  8. Microwave Coupling to ECR and Alternative Heating Methods

    CERN Document Server

    Celona, L.

    2013-12-16

    The Electron Cyclotron Resonance Ion Source (ECRIS) is nowadays the most effective device that can feed particle accelerators in a continuous and reliable way, providing high-current beams of low- and medium-charge-state ions and relatively intense currents for highly charged ions. The ECRIS is an important tool for research with ion beams (in surface, atomic, and nuclear science) while, on the other hand, it implies plasma under extreme conditions and thus constitutes an object of scientific interest in itself. The fundamental aspect of the coupling between the electromagnetic wave and the plasma is hereinafter treated together with some variations to the classical ECR heating mechanism, with particular attention being paid to the frequency tuning effect and two-frequency heating. Considerations of electron and ion dynamics will be presented together with some recent observations connecting the beam shape with the frequency of the electromagnetic wave feeding the cavity. The future challenges of higher-charg...

  9. Performance Analysis and Application of Three Different Computational Methods for Solar Heating System with Seasonal Water Tank Heat Storage

    Directory of Open Access Journals (Sweden)

    Dongliang Sun

    2013-01-01

    Full Text Available We analyze and compare three different computational methods for a solar heating system with seasonal water tank heat storage (SHS-SWTHS. These methods are accurate numerical method, temperature stratification method, and uniform temperature method. The accurate numerical method can accurately predict the performance of the system, but it takes about 4 to 5 weeks, which is too long and hard for the performance analysis of this system. The temperature stratification method obtains relatively accurate computation results and takes a relatively short computation time, which is about 2 to 3 hours. Therefore, this method is most suitable for the performance analysis of this system. The deviation of the computational results of the uniform temperature method is great, and the time consumed is similar to that of the temperature stratification method. Therefore, this method is not recommended herein. Based on the above analyses, the temperature stratification method is applied to analyze the influence of the embedded depth of water tank, the thickness of thermal insulation material, and the collection area on the performance of this system. The results will provide a design basis for the related demonstration projects.

  10. Selection of heat disposal methods for a Hanford Nuclear Energy Center

    International Nuclear Information System (INIS)

    Young, J.R.; Kannberg, L.D.; Ramsdell, J.V.; Rickard, W.H.; Watson, D.G.

    1976-06-01

    Selection of the best method for disposal of the waste heat from a large power generation center requires a comprehensive comparison of the costs and environmental effects. The objective is to identify the heat dissipation method with the minimum total economic and environmental cost. A 20 reactor HNEC will dissipate about 50,000 MWt of waste heat; a 40 reactor HNEC would release about 100,000 MWt. This is a much larger discharge of heat than has occurred from other concentrated industrial facilities and consequently a special analysis is required to determine the permissibility of such a large heat disposal and the best methods of disposal. It is possible that some methods of disposal will not be permissible because of excessive environmental effects or that the optimum disposal method may include a combination of several methods. A preliminary analysis is presented of the Hanford Nuclear Energy Center heat disposal problem to determine the best methods for disposal and any obvious limitations on the amount of heat that can be released. The analysis is based, in part, on information from an interim conceptual study, a heat sink management analysis, and a meteorological analysis

  11. Influence of heat processing methods on the nutrient composition ...

    African Journals Online (AJOL)

    No significant difference (P > 0.05) was obtained in the saponification number of the three samples analyzed and values ranged from 161.3 ±2.92 in RS to 163.0 ± 2.60 in FS. Heat processing (boiling and frying) generally decreased significantly (p<0.05) the crude protein, crude fat, caloric value, Fe, Zn, vitamins A and C as ...

  12. Simulation methods of rocket fuel refrigerating with liquid nitrogen and intermediate heat carrier

    Directory of Open Access Journals (Sweden)

    O. E. Denisov

    2014-01-01

    Full Text Available Temperature preparation of liquid propellant components (LPC before fueling the tanks of rocket and space technology is the one of the operations performed by ground technological complexes on cosmodromes. Refrigeration of high-boiling LPC is needed to increase its density and to create cold reserve for compensation of heat flows existing during fueling and prelaunch operations of space rockets.The method and results of simulation of LPC refrigeration in the recuperative heat exchangers with heat carrier which is refrigerated by-turn with liquid nitrogen sparging. The refrigerating system consists of two tanks (for the chilled coolant and LPC, LPC and heat carrier circulation loops with heat exchanger and system of heat carrier refrigeration in its tank with bubbler. Application of intermediate heat carrier between LPC and liquid nitrogen allows to avoid LPC crystallization on cold surfaces of the heat exchanger.Simulation of such systems performance is necessary to determine its basic design and functional parameters ensuring effective refrigerating of liquid propellant components, time and the amount of liquid nitrogen spent on refrigeration operation. Creating a simulator is quite complicated because of the need to take into consideration many different heat exchange processes occurring in the system. Also, to determine the influence of various parameters on occurring processes it is necessary to take into consideration the dependence of all heat exchange parameters on each other: heat emission coefficients, heat transfer coefficients, heat flow amounts, etc.The paper offers an overview of 10 references to foreign and Russian publications on separate issues and processes occurring in liquids refrigerating, including LPC refrigeration with liquid nitrogen. Concluded the need to define the LPC refrigerating conditions to minimize cost of liquid nitrogen. The experimental data presented in these publications is conformed with the application of

  13. Method of heat decomposition for chemical decontaminating resin waste

    International Nuclear Information System (INIS)

    Kikuchi, Akira.

    1988-01-01

    Purpose: To make resin wastes into non-deleterious state, discharge them into a resin waste storage tank of existent radioactive waste processing facility and store and dispose them. Constitution: In the processing of chemical decontaminating resin wastes, iron exchange resins adsorbing chemical decontaminating agents comprising a solution of citric acid, oxalic acid, formic acid and EDTA alone or as a mixture of them are heated to dry, thermally decomposed and then separated from the ion exchange resins. That is, the main ingredients of the chemical decontaminating agents are heat-decomposed when heated and dried at about 250 deg C in air and converted into non-toxic gases such as CO, CO 2 , NO, NO 2 or H 2 O. Further, since combustion or carbonization of the basic materials for the resin is not caused at such a level of temperature, the resin wastes removed with organic acid and chelating agents are transferred to an existent resin waste storage tank and stored therein. In this way, facility cost and radiation exposure can remarkably be decreased. (Kamimura, M.)

  14. Heat-washout - an objective method for diagnosing neuropathy and atherosclerosis in diabetic patients

    DEFF Research Database (Denmark)

    Midttun, M; Snorgaard, O

    2013-01-01

    The heat-washout method is an objective method that measures cutaneous blood flow rate (BFR) in ml (100 g. min)(-1), previously found useful for measuring toe BFR in non-diabetic patients with claudication.......The heat-washout method is an objective method that measures cutaneous blood flow rate (BFR) in ml (100 g. min)(-1), previously found useful for measuring toe BFR in non-diabetic patients with claudication....

  15. Various methods of heat supply for a building which is operated periodically during the year

    Science.gov (United States)

    Małetka, Marek; Laska, Marta

    2017-11-01

    Stand-alone buildings operated periodically require heat supply for hot water and heating purposes to be carefully analyzed in terms of the technical capabilities, the energy and financial outlays. The paper presents the analysis of heat supply for hot water purposes and central heating in the stand-alone cloakroom building located in Poland. The analysis is undertaken for different variants of heat delivery for a building from electric heaters, gas boiler and district heating solutions to renewable sources applications, namely solar panels and heat pumps. For each solution, usage of usable, final and primary energy was calculated. Also the financial analysis for investments and energy costs were carried out. This analysis has been done in according to SPBT and NPV method for different levels of building use.

  16. Various methods of heat supply for a building which is operated periodically during the year

    Directory of Open Access Journals (Sweden)

    Małetka Marek

    2017-01-01

    Full Text Available Stand-alone buildings operated periodically require heat supply for hot water and heating purposes to be carefully analyzed in terms of the technical capabilities, the energy and financial outlays. The paper presents the analysis of heat supply for hot water purposes and central heating in the stand-alone cloakroom building located in Poland. The analysis is undertaken for different variants of heat delivery for a building from electric heaters, gas boiler and district heating solutions to renewable sources applications, namely solar panels and heat pumps. For each solution, usage of usable, final and primary energy was calculated. Also the financial analysis for investments and energy costs were carried out. This analysis has been done in according to SPBT and NPV method for different levels of building use.

  17. Method of producing oxidation resistant coatings for molybdenum

    International Nuclear Information System (INIS)

    Timmons, G.A.

    1989-01-01

    A method is described for producing a molybdenum element having adherently bonded thereto a thermally self-healing plasma-sprayed coating consisting essentially of a composite of molybdenum and a refactory oxide material capable of reacting with molybdenum oxide under oxidizing conditions to form a substantially thermally stable refractory compound of molybdenum, the method comprising plasma-spraying a coating formed by the step-wise application of a plurality of interbonded plasma-sprayed layers of a composite of molybdenum/refractory oxide material produced from a particulate mixture thereof. The coating comprises a first layer of molybdenum plasma-sprayed bonded to the substrate of the molybdenum element, a second layer of plasma-sprayed mixture of particulate molybdenum/refactory oxide consisting essentially of predominantly molybdenum bonded to the first layer, and succeeding layers of this mixture. The next step is heating the coated molybdenum element under oxidizing conditions to an elevated temperature sufficient to cause oxygen to diffuse into the surface of the multi-layered coating to react with dispersed molybdenum therein to form molybdenum oxide and effect healing of the coating by reaction of the molybdenum oxide with the contained refractory oxide and thereby protect the substrate of the molybdenum element against oxidation

  18. High-Level Heat Resistance of Spores of Bacillus amyloliquefaciens and Bacillus licheniformis Results from the Presence of a spoVA Operon in a Tn1546 Transposon

    Science.gov (United States)

    Berendsen, Erwin M.; Koning, Rosella A.; Boekhorst, Jos; de Jong, Anne; Kuipers, Oscar P.; Wells-Bennik, Marjon H. J.

    2016-01-01

    Bacterial endospore formers can produce spores that are resistant to many food processing conditions, including heat. Some spores may survive heating processes aimed at production of commercially sterile foods. Recently, it was shown that a spoVA operon, designated spoVA2mob, present on a Tn1546 transposon in Bacillus subtilis, leads to profoundly increased wet heat resistance of B. subtilis spores. Such Tn1546 transposon elements including the spoVA2mob operon were also found in several strains of Bacillus amyloliquefaciens and Bacillus licheniformis, and these strains were shown to produce spores with significantly higher resistances to wet heat than their counterparts lacking this transposon. In this study, the locations and compositions of Tn1546 transposons encompassing the spoVA2mob operons in B. amyloliquefaciens and B. licheniformis were analyzed. Introduction of these spoVA2mob operons into B. subtilis 168 (producing spores that are not highly heat resistant) rendered mutant 168 strains that produced high-level heat resistant spores, demonstrating that these elements in B. amyloliquefaciens and B. licheniformis are responsible for high level heat resistance of spores. Assessment of growth of the nine strains of each species between 5.2°C and 57.7°C showed some differences between strains, especially at lower temperatures, but all strains were able to grow at 57.7°C. Strains of B. amyloliquefaciens and B. licheniformis that contain the Tn1546 elements (and produce high-level heat resistant spores) grew at temperatures similar to those of their Tn1546-negative counterparts that produce low-level heat resistant spores. The findings presented in this study allow for detection of B. amyloliquefaciens and B. licheniformis strains that produce highly heat resistant spores in the food chain. PMID:27994575

  19. An analytical method for defining the pump`s power optimum of a water-to-water heat pump heating system using COP

    Directory of Open Access Journals (Sweden)

    Nyers Jozsef

    2017-01-01

    Full Text Available This paper analyzes the energy efficiency of the heat pump and the complete heat pump heating system. Essentially, the maximum of the coefficient of performance of the heat pump and the heat pump heating system are investigated and determined by applying a new analytical optimization procedure. The analyzed physical system consists of the water-to-water heat pump, circulation and well pump. In the analytical optimization procedure the "first derivative equal to zero" mathematical method is applied. The objective function is the coefficient of performance of the heat pump, and the heat pump heating system. By using the analytical optimization procedure and the objective function, as the result, the local and the total energy optimum conditions with respect to the mass flow rate of hot and cold water i. e. the power of circulation or well pump are defined.

  20. DOUBLE TRIALS METHOD FOR NONLINEAR PROBLEMS ARISING IN HEAT TRANSFER

    Directory of Open Access Journals (Sweden)

    Chun-Hui He

    2011-01-01

    Full Text Available According to an ancient Chinese algorithm, the Ying Buzu Shu, in about second century BC, known as the rule of double false position in West after 1202 AD, two trial roots are assumed to solve algebraic equations. The solution procedure can be extended to solve nonlinear differential equations by constructing an approximate solution with an unknown parameter, and the unknown parameter can be easily determined using the Ying Buzu Shu. An example in heat transfer is given to elucidate the solution procedure.

  1. A novel laboratory scale method for studying heat treatment of cake flour

    OpenAIRE

    Chesterton, AKS; Wilson, David Ian; Sadd, PI; Moggridge, Geoffrey Dillwyn

    2014-01-01

    A lab-scale method for replicating the time–temperature history experienced by cake flours undergoing heat treatment was developed based on a packed bed configuration. The performance of heat-treated flours was compared with untreated and commercially heat-treated flour by test baking a high ratio cake formulation. Both cake volume and AACC shape measures were optimal after 15 min treatment at 130 °C, though their values varied between harvests. Separate oscillatory rheometry tests of cake ba...

  2. Initial estimates of the economical attractiveness of a nuclear closed Brayton combined cycle operating with firebrick resistance-heated energy storage

    Directory of Open Access Journals (Sweden)

    Florian Chavagnat

    2018-04-01

    Full Text Available The Firebrick Resistance-Heated Energy Storage (FIRES concept developed by the Massachusetts Institute of Technology aims to enhance profitability of the nuclear power industry in the next decades. Studies carried out at Massachusetts Institute of Technology already provide estimates of the potential revenue from FIRES system when it is applied to industrial heat supply, the likely first application. Here, we investigate the possibility of operating a power plant (PP with a fluoride-salt-cooled high-temperature reactor and a closed Brayton cycle. This variant offers features such as enhanced nuclear safety as well as flexibility in design of the PP but also radically changes the way of operating the PP. This exploratory study provides estimates of the revenue generated by FIRES in addition to the nominal revenue of the stand-alone fluoride-salt-cooled high-temperature reactor, which are useful for defining an initial design. The electricity price data is based on the day-ahead markets of Germany/Austria and the United States (Iowa. The proposed method derives from the equation of revenue introduced in this study and involves simple computations using MatLab to compute the estimates. Results show variable economic potential depending on the host grid but stress a high profitability in both regions. Keywords: Firebrick Resistance-Heated Energy Storage, Nuclear Power Plant, Revenue Estimate, Storage System

  3. Preparation and property investigation of multi-walled carbon nanotube (MWCNT/epoxy composite films as high-performance electric heating (resistive heating element

    Directory of Open Access Journals (Sweden)

    F. X. Wang

    2018-04-01

    Full Text Available A series of multi-walled carbon nanotube (MWCNT/epoxy composite films with a thickness of ~700 µm is prepared by a sequential process of premixing, post dispersing, film casting, and thermal curing. The effects of the physical shear dispersion on the properties of conductive polymer composites as the electric heating element are investigated. The scanning electron microscope (SEM images show that highly efficient conductive networks form with shear dispersions of MWCNTs in the polymer matrix. The electrical resistivity decreases sharply from ~1015 Ω·cm for the neat epoxy resin to ~102 Ω·cm for the composite film with 2.0 wt% MWCNTs in accordance with the percolation behaviour, and a low percolation threshold of ~0.018 wt% is fitted. The electric heating behaviour of the composite film is observed at a low MWCNT content of 0.05 wt% due to the high electrical conductivity. For the composite film with 2.0 wt% MWCNTs, an equilibrium temperature of 115 °C is reached at an applied voltage of 40 V within 30 s. The excellent electric heating behaviour, including the rapid temperature response, electric heating efficiency, and operational stability, is primarily related to the conductive two-dimensional networks consisting of MWCNTs and the thermodynamically stable polymer matrix.

  4. Theoretical simulation of the dual-heat-flux method in deep body temperature measurements.

    Science.gov (United States)

    Huang, Ming; Chen, Wenxi

    2010-01-01

    Deep body temperature reveals individual physiological states, and is important in patient monitoring and chronobiological studies. An innovative dual-heat-flux method has been shown experimentally to be competitive with the conventional zero-heat-flow method in its performance, in terms of measurement accuracy and step response to changes in the deep temperature. We have utilized a finite element method to model and simulate the dynamic process of a dual-heat-flux probe in deep body temperature measurements to validate the fundamental principles of the dual-heat-flux method theoretically, and to acquire a detailed quantitative description of the thermal profile of the dual-heat-flux probe. The simulation results show that the estimated deep body temperature is influenced by the ambient temperature (linearly, at a maximum rate of 0.03 °C/°C) and the blood perfusion rate. The corresponding depth of the estimated temperature in the skin and subcutaneous tissue layer is consistent when using the dual-heat-flux probe. Insights in improving the performance of the dual-heat-flux method were discussed for further studies of dual-heat-flux probes, taking into account structural and geometric considerations.

  5. Resistive heating enhanced soil vapor extraction of chlorinated solvents from trichloroethylene contaminated silty, low permeable soil

    NARCIS (Netherlands)

    Zutphen, M. van; Heron, G.; Enfield, C.G.; Christensen, T.H.

    1998-01-01

    A 2D-laboratory box experiment (12 x 56 x 116 cm) was conducted to simulate the enhancement of soil vapor extraction by the application of low frequency electrical heating Uoule heating) for the remediation of a low permeable, silty soil contaminated with trichloroethylene. Joule heating enlarged

  6. Variation of microstructures and mechanical properties of hot heading process of super heat resisting alloy Inconel 718

    International Nuclear Information System (INIS)

    Choi, Hong Seok; Ko, Dae Chul; Kim, Byung Min

    2007-01-01

    Metal forming is the process changing shapes and mechanical properties of the workpiece without initial material reduction through plastic deformation. Above all, because of hot working carried out above recrystallization temperature can be generated large deformation with one blow, it can produce with forging complicated parts or heat resisting super alloy such as Inconel 718 has the worst forgeability. In this paper, we established optimal variation of hot heading process of the Inconel 718 used in heat resisting component and evaluated mechanical properties hot worked product. Die material is SKD61 and initial temperature is 300 .deg. C. Initial billet temperature and punch velocity changed, relatively. Friction coefficient is 0.3 as lubricated condition of hot working. CAE is carried out using DEFORM software before marking the tryout part, and it is manufactured 150 ton screw press with optimal condition. It is know that forming load was decreased according to decreasing punch velocity

  7. Improved Stress Corrosion Cracking Resistance and Strength of a Two-Step Aged Al-Zn-Mg-Cu Alloy Using Taguchi Method

    Science.gov (United States)

    Lin, Lianghua; Liu, Zhiyi; Ying, Puyou; Liu, Meng

    2015-12-01

    Multi-step heat treatment effectively enhances the stress corrosion cracking (SCC) resistance but usually degrades the mechanical properties of Al-Zn-Mg-Cu alloys. With the aim to enhance SCC resistance as well as strength of Al-Zn-Mg-Cu alloys, we have optimized the process parameters during two-step aging of Al-6.1Zn-2.8Mg-1.9Cu alloy by Taguchi's L9 orthogonal array. In this work, analysis of variance (ANOVA) was performed to find out the significant heat treatment parameters. The slow strain rate testing combined with scanning electron microscope and transmission electron microscope was employed to study the SCC behaviors of Al-Zn-Mg-Cu alloy. Results showed that the contour map produced by ANOVA offered a reliable reference for selection of optimum heat treatment parameters. By using this method, a desired combination of mechanical performances and SCC resistance was obtained.

  8. Analysis of simplified heat transfer models for thermal property determination of nano-film by TDTR method

    Science.gov (United States)

    Wang, Xinwei; Chen, Zhe; Sun, Fangyuan; Zhang, Hang; Jiang, Yuyan; Tang, Dawei

    2018-03-01

    Heat transfer in nanostructures is of critical importance for a wide range of applications such as functional materials and thermal management of electronics. Time-domain thermoreflectance (TDTR) has been proved to be a reliable measurement technique for the thermal property determinations of nanoscale structures. However, it is difficult to determine more than three thermal properties at the same time. Heat transfer model simplifications can reduce the fitting variables and provide an alternative way for thermal property determination. In this paper, two simplified models are investigated and analyzed by the transform matrix method and simulations. TDTR measurements are performed on Al-SiO2-Si samples with different SiO2 thickness. Both theoretical and experimental results show that the simplified tri-layer model (STM) is reliable and suitable for thin film samples with a wide range of thickness. Furthermore, the STM can also extract the intrinsic thermal conductivity and interfacial thermal resistance from serial samples with different thickness.

  9. A method for increase abrasive wear resistance parts by obtaining on methods casting on gasifying models

    Science.gov (United States)

    Sedukhin, V. V.; Anikeev, A. N.; Chumanov, I. V.

    2017-11-01

    Method optimizes hardening working layer parts’, working in high-abrasive conditions looks in this work: bland refractory particles WC and TiC in respect of 70/30 wt. % prepared by beforehand is applied on polystyrene model in casting’ mould. After metal poured in mould, withstand for crystallization, and then a study is carried out. Study macro- and microstructure received samples allows to say that thickness and structure received hardened layer depends on duration interactions blend harder carbides and liquid metal. Different character interactions various dispersed particles and matrix metal observed under the same conditions. Tests abrasive wear resistance received materials of method calculating residual masses was conducted in laboratory’ conditions. Results research wear resistance showed about that method obtaining harder coating of blend carbide tungsten and carbide titanium by means of drawing on surface foam polystyrene model before moulding, allows receive details with surface has wear resistance in 2.5 times higher, than details of analogy steel uncoated. Wherein energy costs necessary for transformation units mass’ substances in powder at obtained harder layer in 2.06 times higher, than materials uncoated.

  10. Fundamental studies on electron beam welding on heat-resistant superalloys for nuclear plants, 2

    International Nuclear Information System (INIS)

    Arata, Yoshiaki; Terai, Kiyohide; Nagai, Hiroyoshi; Shimizu, Shigeki; Aota, Toshiichi.

    1978-01-01

    In this report, the correlation was discussed between the susceptibility to weld cracking in electron beam welding of heat-resistant superalloys for nuclear plants and its characteristics of hot ductility. Trans-Varestraint and Varestraint tests. Obtained conclusions may be summarized as follows, using technical symbols which are given meanings in this report. 1) Such criteria obtained in the hot ductility test are herein employed to evaluate the susceptibility to microcracking as sub(ND) T sub(H), sub(ND) T sub(C), ΔT sub(H.C) (= sub(ND) T sub(H) - sub(ND) T sub(C)) and sub(B) T sub(R) (= T sub(L) - sub(ND) T sub(C)). Both with the decrease of sub(ND) T sub(H) and sub(ND) T sub(C) and with the increase of ΔT sub(H.C) and sub(B) T sub(R), superalloys are considered to become more susceptible to microcracking. Of these criteria, ΔT sub(H.C.) and sub(B) T sub(R) correlate best with q sub(CR) which is one of the effective criteria to evaluate the susceptibility to microcracking in the electron beam welding. 2) It is recognized that ΔT sub(H.C) and sub(B) T sub(R) in hot ductility test correlate well with sub(TV) T sub(R.5%) in Trans-Varestraint test and sub(V) C sub(m.1%) in the Varestraint test. 3) sub(TV) T sub(R.5%) in the Trans-Varestraint test and sub(V) C sub(m.1%) in the Varestraint test are respectively effective to evaluate the susceptibility to microcracking. Moreover, these criteria clearly correlate with q sub(CR). (auth.)

  11. Aging of a cast 35Cr-45Ni heat resistant alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sustaita-Torres, Ireri A., E-mail: ireri.sustaita@gmail.com [Unidad Academica de Ingenieria, Universidad Autonoma de Zacatecas, 98000 Zacatecas (Mexico); Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, 66450 San Nicolas de los Garza (Mexico); Haro-Rodriguez, Sergio, E-mail: haros907@hotmail.com [Unidad Academica de Ingenieria, Universidad Autonoma de Zacatecas, 98000 Zacatecas (Mexico); Guerrero-Mata, Martha P., E-mail: martha.guerreromt@uanl.edu.mx [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, 66450 San Nicolas de los Garza (Mexico); Garza, Maribel de la, E-mail: maribeldelagarza@yahoo.com.mx [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, 66450 San Nicolas de los Garza (Mexico); Valdes, Eduardo, E-mail: eduardo.valdes.57@gmail.com [Instituto Tecnologico de Saltillo, 25280 Saltillo (Mexico); Deschaux-Beaume, Frederic, E-mail: deschaux@iut-nimes.fr [Mechanical and Civil Engineering Laboratories, Universite de Montpellier 2, IUT Nimes, 30907 Nimes (France); and others

    2012-04-16

    Highlights: Black-Right-Pointing-Pointer The as-cast microstructure is made of an austenitic matrix and primary carbides. Black-Right-Pointing-Pointer The carbides are of two different types: Cr- and Nb-rich. Black-Right-Pointing-Pointer The microstructure changes during aging. Black-Right-Pointing-Pointer These microstructural changes result in the degradation of mechanical properties. - Abstract: The microstructural evolution during aging and its effect on the mechanical properties of a centrifugally cast 35Cr-45Ni heat resistant alloy was studied by means of optical and electron microscopy, and by mechanical testing in samples aged in air at 750 Degree-Sign C for a period of time of up to 1000 h. The as-cast microstructure consisted of an austenitic matrix and a network of two types of primary carbides that were identified as NbC and M{sub 7}C{sub 3} by their light and dark tones when viewed in backscattered electron mode in a scanning electron microscope. Aging promoted the occurrence of different phenomena such as the transformation of primary M{sub 7}C{sub 3} to M{sub 23}C{sub 6} carbides, precipitation of secondary M{sub 23}C{sub 6} carbides and the transformation of NbC to Nb{sub 3}Ni{sub 2}Si. It was found that aging promoted an increase in Vickers microhardness of more than 50%, the increment in tensile strength of around 20% and the reduction in ductility of close to 70%.

  12. Comparison between different methods of measurement of momentum and sensible heat fluxes over canopies

    Directory of Open Access Journals (Sweden)

    Marc Aubinet

    1997-01-01

    Full Text Available Différent methods of measurement of momentum and sensible heat flux densifies are presented and compared above a gras covered fallow. The aerodynamic (AD and eddy covariance (EC methods are presented and compared for both momentum and sensible heat measurements. In addition, the temperature fluctuation (TF method is compared to the HEC method for the sensible heat flux measurement. The AD and EC methods are in good agreement for the momentum flux measurements. For the sensible heat flux, the AD method is very sensible to temperature errors. So it is unusable during night and gives biased estimations during the day. The TF method gives only estimations of the sensible heat flux. It is in good agreement with the EC method during the day but diverges completely during night, being unable to disceming positive from négative fluxes. From the three methods, the EC method is the sole that allows to measure continuously both momentum and sensible heat flux but it requires a loud data treatment. We présent in this paper the algorithm used for this treatment.

  13. Study of new heat treatment parameters for increasing mechanical strength and stress corrosion cracking resistance of 7075 Aluminium alloy

    OpenAIRE

    Silva, G.; Rivolta, B.; Gerosa, R.; Derudi, U.

    2013-01-01

    For many years 7075 Aluminum alloys have been widely used especially in those applications for which highmechanical performances are required. It is well known that the alloy in the T6 condition is characterized bythe highest ultimate and yield strengths, but, at the same time, by poor stress corrosion cracking (SCC)resistance. For this reason, in the aeronautic applications, new heat treatments have been introduced toproduce T7X conditions, which are characterized by lower mechanical strengt...

  14. Evaluation of alternative methods of simulating asymmetric bulk heating in fusion reactor blanket/shield components

    International Nuclear Information System (INIS)

    Deis, G.A.; Longhurst, G.R.; Miller, L.G.; Wadkins, R.P.; Wessol, D.E.

    1981-10-01

    As a part of Phase O, Test Program Element-II of the Office of Fusion Energy First Wall/Blanket/Shield Engineering Test Program, a study was conducted by EG and G Idaho, Inc., to identify, characterize, and recommend alternative approaches for simulating fusion bulk heating in blanket/shield components. This is the report on that effort. Since the usefulness of any simulation approach depends upon the particular experiment considered, classes of problem types (thermal-hydraulic, thermomechanical, etc.) and material types (structure, solid breeder, etc.) are developed. The evaluation of the various simulation approaches is performed for the various significant combinations of problem class and material class. The simulation approaches considered are discrete-source heating, direct resistance, electromagnetic induction, microwave heating, and nuclear heating. From the evaluations performed for each experiment type, discrete - source heating emerges as a good approach for bulk heating simulation in thermal - hydraulics experiments, and nuclear heating appears to be a good approach in experiments addressing thermomechanics and combined thermal-hydraulic/thermomechanics

  15. Thermal resistance of rotating closed-loop pulsating heat pipes: Effects of working fluids and internal diameters

    Directory of Open Access Journals (Sweden)

    Kammuang-Lue Niti

    2017-01-01

    Full Text Available The objective of this study was to experimentally investigate the effects of working fluids and internal diameters on the thermal resistance of rotating closed-loop pul¬sating heat pipes (RCLPHP. The RCLPHP were made of a copper tube with internal diameters of 1.50 mm and 1.78 mm, bent into the shape of a flower petal, and arranged into a circle with 11 turns. The evaporator section was located at the outer end of the tube bundle. R123, ethanol, and water were filled as the working fluids. The RCLPHP was rotated at centrifugal accelerations 0.5, 1, 3, 5, 10, and 20 times of the gravitational acceleration considered at the connection between the evaporator and the condenser sections. The heat input was varied from 30 W to 50 W, and then to 100 W, 150 W, and 200 W. It can be concluded that when the latent heat of evaporation increases, the pressure difference between the evaporator and the condenser sections decreases, and the thermal resistance increases. Moreover, when the internal diameter increases, the driving force increases and the frictional force proportionally decreases, or the Karman number increases, and the thermal resistance decreases.

  16. Non-linear heat transfer computer code by finite element method

    International Nuclear Information System (INIS)

    Nagato, Kotaro; Takikawa, Noboru

    1977-01-01

    The computer code THETA-2D for the calculation of temperature distribution by the two-dimensional finite element method was made for the analysis of heat transfer in a high temperature structure. Numerical experiment was performed for the numerical integration of the differential equation of heat conduction. The Runge-Kutta method of the numerical experiment produced an unstable solution. A stable solution was obtained by the β method with the β value of 0.35. In high temperature structures, the radiative heat transfer can not be neglected. To introduce a term of the radiative heat transfer, a functional neglecting the radiative heat transfer was derived at first. Then, the radiative term was added after the discretion by variation method. Five model calculations were carried out by the computer code. Calculation of steady heat conduction was performed. When estimated initial temperature is 1,000 degree C, reasonable heat blance was obtained. In case of steady-unsteady temperature calculation, the time integral by THETA-2D turned out to be under-estimation for enthalpy change. With a one-dimensional model, the temperature distribution in a structure, in which heat conductivity is dependent on temperature, was calculated. Calculation with a model which has a void inside was performed. Finally, model calculation for a complex system was carried out. (Kato, T.)

  17. System and method for determining the net output torque from a waste heat recovery system

    Science.gov (United States)

    Tricaud, Christophe; Ernst, Timothy C.; Zigan, James A.

    2016-12-13

    The disclosure provides a waste heat recovery system with a system and method for calculation of the net output torque from the waste heat recovery system. The calculation uses inputs from existing pressure and speed sensors to create a virtual pump torque sensor and a virtual expander torque sensor, and uses these sensors to provide an accurate net torque output from the WHR system.

  18. Method for preventing and/or treating insulin resistance

    NARCIS (Netherlands)

    Nieuwdorp, M.; Vos, de W.M.

    2013-01-01

    The present invention describes use of Eubacterium hallii et rel. and/or Alcaligenes faecalis et rel., as well as pharmaceutical, food, or feed compositions comprising these bacteria, as a medicament, in particular for preventing and/or treating insulin resistance and/or insulin resistance-related

  19. Tabular method of critical heat flux description in square packing rod bundles

    International Nuclear Information System (INIS)

    Bobkov, V.P.; Smogalev, I.P.

    2003-01-01

    Elaborations of harnessing tabular method for the description and calculation of critical heat fluxes in square packing rod bundles are presented. The tabular method for fuel rod triangular assemblies derived from using basic table for critical heat fluxes in triangular fuel assemblies demonstrates good results. For the harnessing tabular method in square packing rod bundles correction functions reflecting specific geometry were found. Comparative evaluations of calculated values for the critical heat fluxes with experimental ones are presented. Good agreement of calculations with experiments is noted in all range of parameters [ru

  20. Method of forming oxide coatings. [for solar collector heating panels

    Science.gov (United States)

    Mcdonald, G. E. (Inventor)

    1983-01-01

    This invention is concerned with an improved plating process for covering a substrate with a black metal oxide film. The invention is particularly directed to making a heating panel for a solar collector. A compound is electrodeposited from an aqueous solution containing cobalt metal salts onto a metal substrate. This compound is converted during plating into a black, highly absorbing oxide coating which contains hydrated oxides. This is achieved by the inclusion of an oxidizing agent in the plating bath. The inclusion of an oxidizing agent in the plating bath is contrary to standard electroplating practice. The hydrated oxides are converted to oxides by treatment in a hot bath, such as boiling water. An oxidizing agent may be added to the hot liquid treating bath.