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Sample records for composition heat treatment

  1. Compositions produced using an in situ heat treatment process

    Energy Technology Data Exchange (ETDEWEB)

    Roes, Augustinus Wilhelmus Maria; Nair, Vijay; Munsterman, Erwin Hunh; Van Bergen, Petrus Franciscus; Van Den Berg, Franciscus Gondulfus Antonius

    2013-05-28

    Methods for treating a subsurface formation and compositions produced therefrom are described herein. At least one method for producing hydrocarbons from a subsurface formation includes providing heat to the subsurface formation using an in situ heat treatment process. One or more formation particles may be formed during heating of the subsurface formation. Fluid that includes hydrocarbons and the formation particles may be produced from the subsurface formation. The formation particles in the produced fluid may include cenospheres and have an average particle size of at least 0.5 micrometers.

  2. Compositions produced using an in situ heat treatment process

    Energy Technology Data Exchange (ETDEWEB)

    Roes, Augustinus Wilhelmus Maria [Houston, TX; Nair, Vijay [Katy, TX; Munsterman, Erwin Henh [Amsterdam, NL; Van Bergen, Petrus Franciscus [Amsterdam, NL; Van Den Berg, Franciscus Gondulfus Antonius (Amsterdam, NL)

    2009-10-20

    Systems, methods, and heaters for treating a subsurface formation are described herein. At least one method for producing hydrocarbons from a subsurface formation includes providing heat to the subsurface formation using an in situ heat treatment process. One or more formation particles may be formed during heating of the subsurface formation. Fluid that includes hydrocarbons and the formation particles may be produced from the subsurface formation. The formation particles in the produced fluid may include cenospheres and have an average particle size of at least 0.5 micrometers.

  3. Structural transformations and properties of titanium-aluminum composite during heat treatment

    Science.gov (United States)

    Pervukhin, L. B.; Kryukov, D. B.; Krivenkov, A. O.; Chugunov, S. N.

    2017-08-01

    The link between the parameters of heat treatment of a layered titanium-aluminum composite material obtained by explosive welding with the formation of intermetallic compounds in it has been analyzed. The results of measurements of the microhardness of the composite and the thickness of the interlayer of the intermetallic phase obtained using different regimes of heat treatment have been discussed. Special attention has been paid to estimating the composition of the intermetallic phase in the composite prepared by explosive welding.

  4. 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.

  5. Heat treatment of a direct composite resin: influence on flexural strength

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    Caroline Lumi Miyazaki

    2009-09-01

    Full Text Available The purpose of this study was to evaluate the flexural strength of a direct composite, for indirect application, that received heat treatment, with or without investment. One indirect composite was used for comparison. For determination of the heat treatment temperature, thermogravimetric analysis (TGA and differential scanning calorimetry (DSC were performed, considering the initial weight loss temperature and glass transition temperature (Tg. Then, after photoactivation (600 mW/cm² - 40 s, the specimens (10 x 2 x 2 mm were heat-treated following these conditions: 170ºC for 5, 10 or 15 min, embedded or not embedded in investment. Flexural strength was assessed as a means to evaluate the influence of different heat treatment periods and investment embedding on mechanical properties. The data were analyzed by ANOVA and Tukey's test (α = 0.05. TGA showed an initial weight loss temperature of 180ºC and DSC showed a Tg value of 157°C. Heat treatment was conducted in an oven (Flli Manfredi, Italy, after 37°C storage for 48 h. Flexural strength was evaluated after 120 h at 37°C storage. The results showed that different periods and investment embedding presented similar statistical values. Nevertheless, the direct composite resin with treatments presented higher values (178.7 MPa compared to the indirect composite resin (146.0 MPa and the same direct composite submitted to photoactivation only (151.7 MPa. Within the limitations of this study, it could be concluded that the heat treatment increased the flexural strength of the direct composite studied, leading to higher mechanical strength compared to the indirect composite.

  6. Effect of heat treatment on the flexural properties of a titanium matrix composite

    Science.gov (United States)

    Warrier, S. G.; Lin, R. Y.

    1992-01-01

    Titanium matrix composites (TMC) reinforced with carbon fibers are widely used in the aerospace industry due to their light weight, high strength and modulus and the retention of their strength and modulus at elevated temperatures. Liquid infiltration, a low cost technique for making TMCs, has been little used due to the extent of the reaction between titanium and carbon during fabrication. Rapid infrared processing (RIP) has been developed as a technique for reducing interfacial reaction during composite fabrication. The strength and modulus of composites produced using RIP were higher than or comparable to those for other composites. This paper examines the effect of heat treatment on the room temperature flexural strength and modulus of TMC produced using RIP. The experiments carried out are described and results are presented. Results showed increased flexural strength of the composites upon aging at temperatures of 800 and 900 degrees C. This increased strength may be due to increased strength of the matrix.

  7. Optimization of post-consolidation heat treatment on particulate reinforced metal matrix composites

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    Montilla, K.; Ravichandran, G. [California Institute of Technology, Pasadena, CA (United States)

    1995-12-31

    Titanium/SiC particulate reinforced metal matrix composites (MMC) continue to receive a great deal of attention due to their enhanced strength, stiffness and wear characteristics. A significant limiting factor in the production of Titanium based MMCs has been the detrimental interfacial reaction zone which occurs during conventional processing techniques (i.e., extrusion, hot rolling). Shock wave consolidation has proven to be an efficient technique for producing crack free, fully dense particulate reinforced metal matrix composites with no interfacial reaction zone. The purpose of this work was to look beyond the consolidation process into post consolidation heat treatments of shock consolidated MMCS. The consolidation of the green compact is accomplished by the passage of a strong shock wave through the powder. It is widely recognized that post consolidation heat treatment is essential in achieving good mechanical properties. The identification of the optimal annealing schedule according to reinforcement size and volume fraction must be established in order to improve the overall mechanical response of the composite. A limited amount of research has been directed towards investigating annealing schedules at relatively low temperatures with an extended heating interval. The current status of this research will be presented.

  8. EFFECT OF HEAT TREATMENT ON THERMAL PROPERTIES OF PITCH-BASED AND PAN-BASED CARBON-CARBON COMPOSITES

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Sardar S. [Southern Illinois University; Dinwiddie, Ralph Barton [ORNL; Porter, Wallace D [ORNL; Lance, Michael J [ORNL; Fillip, Peter [Southern Illinois University

    2011-01-01

    Thermal properties of two directional (2D) pitch-based carbon fiber with charred resin and three directional (3D) PAN-based carbon fiber with CVI carbon matrix C/C composite were investigated for non-heat treated (NHT) and heat treated (HT) materials through the thickness (z-direction). Heat treatment was performed at 1800, 2100 and 2400 oC for 1-hr in inert argon atmosphere. Thermal diffusivity, heat capacity and bulk density were measured to calculate thermal conductivity. Thermal diffusivity and conductivity was the highest for 3D C/C heat treated at maximum temperature with non-heat treated one exhibiting the lowest one. Similarly, 2D C/C heat treated at maximum temperature exhibited the highest thermal diffusivity and thermal conductivity. Polarized light microscopy (PLM) images of HTT C/C show a progressive improvement in microstructure when compared to NHT C/C. However, HTT 2D and 3D C/C composites exhibited extensive shrinkage of charred resin and CVI carbon matrix, respectively, from fibers resulting in intra and inter-bundles cracking when compared to NHT one. Raman spectroscopy and XRD results of NHT and HTT C/C indicated increased ordering of structure. A progressive improvement in thermal properties was observed with increased heat treatment temperatures.

  9. Compressive strength measurements of hybrid dental composites treated with dry heat and light emitting diodes (LED post cure treatment

    Directory of Open Access Journals (Sweden)

    Jenny Krisnawaty

    2014-11-01

    Full Text Available Hybrid composites are mostly used on large cavities as restorative dental materials, whether it is used directly or indirectly. The mechanical properties of composite resin shall increase if it is treated with post cure treatment. The aim of this study is to evaluate compressive strength differences between dry heat and Light Emitting Diodes (LED treatment on the hybrid dental composite. A quasi-experimental was applied on this research with a total of 30 samples that were divided into two groups. Each sample was tested using LLOYD Universal Testing Machine with 1 mm/min speed to evaluate the compressive strength. The compressive strength results were marked when the sample was broken. The results of two groups were then analyzed using t-test statistical calculation. The results of this study show that post cure treatment on hybrid composite using LED light box (194.138 MPa was lower than dry heat treatment (227.339 MPa, which was also significantly different from statistical analysis. It can be concluded that compressive strength of LED light box was lower than dry heat post-cure treatment on the hybrid composite resin.

  10. The Role of Alloy Composition and T7 Heat Treatment in Enhancing Thermal Conductivity of Aluminum High Pressure Diecastings

    Science.gov (United States)

    Lumley, Roger N.; Deeva, Natalia; Larsen, Robert; Gembarovic, Jozef; Freeman, Joe

    2013-02-01

    The thermal conductivity of some common and experimental high pressure diecasting (HPDC) Al-Si-Cu alloys is evaluated. It is shown that the thermal conductivity of some compositions may be increased by more than 60 pct by utilizing T7 heat treatments. This may have substantial performance and cost benefits for applications where thermal management is a key design parameter.

  11. Development of a Cast Al-Mg2Si-Si In Situ Composite: Microstructure, Heat Treatment, and Mechanical Properties

    Science.gov (United States)

    Georgatis, E.; Lekatou, A.; Karantzalis, A. E.; Petropoulos, H.; Katsamakis, S.; Poulia, A.

    2013-03-01

    An Al-11Mg2Si-Si in situ composite was prepared by a modified investment casting technique that employs sub-pressure for castability improvement and immersion of ceramic shell molds in fluidized beds of silica sand and iron particles for heat extraction improvement. The microstructure of the as-cast composite is explained according to the pseudoeutectic Al-Mg2Si phase diagram. The positive effect of a decreased number of mold investment layers and cooling assisted by immersion of the mold in a metallic bed on the tensile strength and hardness of the heat treated composite is noted. A minor presence of Fe in the master alloys constitutes an essential factor for the brittleness of the composite. Solution treatment notably improves the tensile strength of the composite; however, prolonged treatment deteriorates its ductility. The effect of time and temperature of the aging treatment on the hardness of the composite is investigated. The positive influence of cooling assisted by a metallic fluidized bed on the effectiveness of the aging treatment is noticed.

  12. The effect of heat treatment on the chemical composition of canned ...

    African Journals Online (AJOL)

    Beef, pork and chicken meat were used in this study. Heat treatments were carried out at 115 ºC in stationary and rotating autoclaves, 125 ºC in stationary and rotating autoclaves, 125 ºC in stationary and 125 ºC but higher Fo value in stationary and rotating autoclaves. The results of the analysis showed higher protein ...

  13. Effects of heat treatment on mechanical properties and microstructure of tungsten fi ber reinforced grey cast iron matrix composites

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    Peng jianHong

    2009-11-01

    Full Text Available In this study, grey cast iron matrix composites reinforced by different volume fractions of tungsten fibers (Vr = 0.95 %, 1.90 %, 2.85 %, 3.80 % were investigated in as-cast and under the heat treatment temperatures of 1,000℃ and 1,100℃. The microstructure and mechanical properties of the composites were analyzed and tested by means of SEM, micro-hardness tester and three-point bend testing. The results show that with increasing of the volume fraction of tungsten fibers, the composites reinforced by the tungsten fiber have higher fl exural strength and modulus than that of cast iron without reinforcement, and the fl exural strength increases with the increasing of heat treatment temperatures. Due to diffusion reaction between matrix and reinforcing phases, the process of heat treatment, the number of graphite fl akes in the matrix seemingly becomes lower; and some hard carbide particles are formed around the residual tungsten fi bers. Not only does the hardness of both matrix and reinforcement change tremendously, but also the region of reinforcement is also extended from the original 0.11 mm to 0.19 mm in radius.

  14. Effect of Heat-Treatment and Composition on Structure and Luminescence Properties of Spinel-Type Solid Solution Nanocrystals.

    Science.gov (United States)

    Sakoda, Kazuki; Hirano, Masanori

    2015-08-01

    The compositional dependence of the structure and properties of spinel-type solid solutions, Zn(A,Ga)2O4 was investigated by comparison with samples hydrothermally prepared and those after heat treatment at 1000 °C in air. Nanocrystalline spinel-type solid solutions in the whole composition range in the ZnAl2O4-ZnGa2O4 system were directly formed from the aqueous precursor solutions of ZnSO4, Al(NO3)3 and Ga(NO3)3 under hydrothermal conditions at 180 °C for 5 h in the presence of tetramethylammonium hydroxide. The incorporation of aluminum into the lattice, Zn(AlxGa1-x)2O4, resulted in lower crystallinity of the spinel. The relationship between the lattice parameter of as-prepared samples and the Al atomic ratio in the spinel composition was slightly apart from the ideal linear relationship that was obtained in the samples after heat treatment at 1000 °C. The optical band gap of both as-prepared solid solutions and those heat treated linearly increased from 4.1~4.2 to 5.25 eV by the incorporation of aluminum ion into the lattice, Zn(AlxGa1-x)2O4. Two main broad-band emission spectra centered at around 360 and 430 nm in the range of 300-600 nm were observed in the spinel solid solutions under excitation at 270 nm, thought their broad-band emission spectra and their peak wavelengths subtly changed depending on the composition and heat treatment.

  15. Research of High-Heat Treatment Effect on Phase and Chemical Composition of the VKNA-1V Alloy

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    M. V. Unchikova

    2015-01-01

    Full Text Available The paper dwells on the features of the chemical composition and structure of alloys based on Ni3Al. It examines the effect of heat treatment on the structure and phase parameters and on the short-term strength of the intermetallic VKNA-1B alloy.Smelting bar stock was made by technique of vacuum induction. A directional solidification method was used to provide heat treatment of samples on the UVNS-4 installation.The heat treatment was performed in the following modes: heating to a temperature of 1200, 1290, 1300 ° C, holding for 100, 4, 4 hours, respectively, furnace cooling to 800 ° C, then air-cooling. For heating was used the batch furnace VEBK S 400/100 with a maximum operating temperature of 1350 ° C. Samples were loaded in the furnace at 800 0C.The phase composition of the VKNA-1B alloy was examined through physicochemical analysis based on electrochemical insulating phases in different electrolytes. The composition and quantity of the isolated phases were determined by the results of X-ray and chemical analysis methods.To analyse the microstructure was used a scanning electron microscope JSM-840. In original cast state the VKNA-1B alloy has a cellular-dendritic structure. In the axes of the dendrites there is a γ'-phase (~ 75-80% vol. surrounded by a viscous γ-phase in the form of thin layers; in the inter-dendritic regions there are large particles of γ'-phase. The increasing temperature of heat treatment comes with coarsening γ'-phase particles in inter-dendritic regions and, essentially, has no effect on the phase composition of the alloy. Results of mechanical tensile tests have shown that the alloy retains high strength values after long-term exposure and the increasing cell size of γ'-phase in the axes of the dendrites when raising the temperature leads to an increase in short-term strength of the alloy.

  16. Rapid automated materials synthesis instrument: exploring the composition and heat-treatment of nanoprecursors toward low temperature red phosphors.

    Science.gov (United States)

    Lin, Tian; Kellici, Suela; Gong, Kenan; Thompson, Kathryn; Evans, Julian R G; Wang, Xue; Darr, Jawwad A

    2010-05-10

    We report on the commissioning experimental run of the rapid automated materials synthesis instrument (RAMSI), a combinatorial robot designed to manufacture, clean, and print libraries of nanocrystal precursor solid compositions. The first stage of RAMSI, parallel synthesis, uses a fully automated high throughput continuous hydrothermal (HiTCH) flow reactor for automatic metal salt precursor mixing, hydrothermal flow reaction, and sample slurry collection. The second stage of RAMSI provides integrated automated cleanup, and the third section is a ceramic printing function. Nanocrystal precursor solid ceramics were synthesized from precursor solutions and collected into 50 mL centrifuge tubes where they were cleaned by multiple centrifugation and redispersion cycles (monitored by intelligent scanning turbidimetry) and printed with an automated pipette. Eight unique compositions of a model phosphor library comprising pure nano-Y(OH)(3) and Eu(3+) doped-yttrium hydroxide, Y(OH)(3):Eu(3+) nanocrystal precursor solid were synthesized (with 2 centrifuge tubes' worth collected per composition), processed, and printed in duplicate as 75, 100, and 125 microL dots in a 21.6 ks (6 h) experiment (note: the actual time for synthesis of each sample tube was only 12 min so up to 60 compositions could easily be synthesized in 12 h if one centrifuge tube per composition was collected instead). The Y(OH)(3):Eu(3+) samples were manually placed in a furnace and heat-treated in air for 14.4 ks (4 h) in the temperature range 200-1200 at 100 degrees C intervals (giving a total of 84 samples plus one as-prepared pure Y(OH)(3) sample). The as-prepared and heat-treated ceramic samples were affixed to 4 mm wide hemispherical wells in a custom-made aluminum well-plate and analyzed using a fluorescence spectrometer. When the library was illuminated with a 254 nm light source (and digitally imaged and analyzed), the 3 mol % Eu(3+) sample heat-treated at 1200 degrees C gave the most intense

  17. Effects of post-heat treatment on microstructure and properties of laser cladded composite coatings on titanium alloy substrate

    Science.gov (United States)

    Li, G. J.; Li, J.; Luo, X.

    2015-01-01

    The composite coatings were produced on the Ti6Al4V alloy substrate by laser cladding. Subsequently, the coatings were heated at 500 °C for 1 h and 2 h and then cooled in air. Effects of post-heat treatment on microstructure, microhardness and fracture toughness of the coatings were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), optical microscopy (OM). Wear resistance of the coatings was evaluated under the dry sliding reciprocating friction condition at room temperature. The results indicated that the coatings mainly consist of a certain amount of coarse white equiaxed WC particles surrounded by the white-bright W2C, a great deal of fine dark spherical TiC particles and the matrix composed of the α(Ti), Ti2Ni and TiNi phases. Effects of the post-heat treatment on phase constituents and microstructure of the coatings were almost negligible due to the low temperature. However, the post-heat treatment could decrease the residual stress and increase fracture toughness of the coatings, and fracture toughness of the coatings was improved from 2.77 MPa m1/2 to 3.80 MPa m1/2 and 4.43 MPa m1/2 with the heat treatment for 1 h and 2 h, respectively. The mutual role would contribute to the reduction in cracking susceptibility. Accompanied with the increase in fracture toughness, microhardness of the coatings was reduced slightly. The dominant wear mechanism for all the coatings was abrasive wear, characterized by micro-cutting or micro-plowing. The heat treatment could significantly decrease the average friction coefficient and reduce the fluctuation of the friction coefficient with the change in sliding time. The appropriate heat treatment time (approximately 1 h) had a minimal effect on wear mass loss and volume loss. Moreover, the improvement in fracture toughness will also be beneficial to wear resistance of the coatings under the long service.

  18. Mechanical and Tribological Characterization of Al-Mg2Si Composites After Yttrium Addition and Heat Treatment

    Science.gov (United States)

    Jafari Nodooshan, H. R.; Liu, Wencai; Wu, Guohua; Bahrami, A.; Pech-Canul, M. I.; Emamy, M.

    2014-04-01

    In this study, the effect of heat treatment and yttrium additions on the microstructure, mechanical properties, and tribological behavior of Al-15% Mg2Si cast composites was investigated. The microstructural study revealed the presence of both primary and secondary Mg2Si phases in all composite specimens and also Y-containing intermetallics (Al2Y phases) at higher concentrations. It was also found that Y addition does not change the size and morphology of primary Mg2Si particles considerably, but the pseudo-eutectic Mg2Si changed from a flake-like morphology to fine fibrous or rod-like one. The results show that proper content of Y additions can reduce the amount of Mg2Si phase through dissolving it into the matrix, lead to the precipitation of Al2Y phase and improve the mechanical properties. Modified composites with 0.5% Y exhibited an ultimate tensile strength (UTS) of 290 MPa with an elongation of 4.3%. After exposing the composite to solution treatment at 520 °C for 4 h, the tensile strength of the composite continuously increased with the increase of Y content, and reached the maximum at 1% Y. The maximum UTS and elongation at room temperature for the heat-treated composites are 294 MPa and 7.4%, respectively. In the cast specimen, fracture surfaces are covered by packets with coarse steps, suggesting a brittle mode of failure. Modified composites with 0.5 wt.% Y contain several cracked particles together with a few decohered primary Mg2Si particles. In solution heat-treated state, dimples present at the fracture surface are rather coarse but homogenous, showing a semi-ductile mode of fracture. Wear test results showed that the wear resistance of all specimens increases with the addition of Y up to 0.3 wt.%. Scanning electron microscopic observations of the worn surfaces revealed that the dominant wear mechanism was abrasive wear accompanied by some delamination wear mode.

  19. Influence of composition, heat treatment and neutron irradiation on the electrical conductivity of copper alloys

    DEFF Research Database (Denmark)

    Eldrup, Morten Mostgaard; Singh, B.N.

    1998-01-01

    The electrical conductivity of three different types of copper alloys, viz. CuNiBe, CuCrZr and Cu-Al(2)O(3) as well as of pure copper are reported. The alloys have undergone different pre-irradiation heat treatments and have been fission-neutron irradiated up to 0.3 dpa. In some cases post......-irradiation annealing has been carried out. The results are discussed with reference to equivalent Transmission Electron Microscopy results on the microstructure of the materials. The CuNiBe has the lowest conductivity (less than or equal to 55% of that of pure Cu), and Cu-Al(2)O(3) the highest (75-90% of pure Cu). (C...

  20. Effect of silicone oil heat treatment on the chemical composition, cellulose crystalline structure and contact angle of Chinese parasol wood.

    Science.gov (United States)

    Okon, Kufre Edet; Lin, Fengcai; Chen, Yandan; Huang, Biao

    2017-05-15

    The effect of silicone oil heat treatment (SOTH) on the chemical composition, cellulose crystalline structure, thermal degradation and contact angle of Chinese parasol wood were examined in this study. Samples were heated at 150°C, 180°C and 210°C for 2h and 8h, after SOHT chemical composition, fourier transformed infrared (FTIR), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) of the treated samples were evaluated. Results showed that the chemical components of the wood were affected after SOHT particularly when treated at 210°C for 8h. Changes in the chemical components was due to the degradation of biopolymer components of the wood during SOHT. The crystallinity index of cellulose and contact angle of the SOHT samples was increased. The findings demonstrate the potential of SOHT for modification of wood. Thus an economical and eco-friendly approach to thermally modified wood was achieved in this study. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Effect of Heat Treatment and Salt Concentration on Free Amino Acids Composition of Sudanese Braided (Muddaffara Cheese during Storage

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    Mohamed O. E. Altahir

    2014-08-01

    Full Text Available The aim of this study was to assess the effect of heat treatment and salt concentrations (0, 5, and 10% on the free amino acids (FAA composition of Sudanese braided cheese (BC ripened for up to 3 months at 5±2°C. Heat and salt concentration significantly affected the FAA of braided cheese. The free amino acids concentrations of BC ripened in 0%, 5%, and 10% salted whey (SW were significantly fluctuated. Under ripening conditions tested (salt level + time, braided cheese made from pasteurized milk (BCPM had consistently lower values of FAA than braided cheese made from raw milk (BCRM. In fresh cheese, the major FAA in BCRM were Glu (36.12 nmol/ml, Leu (26.77nmol/ml and Lys (14.51 nmol/ml while the major ones in BCPM were Lys (2.94 nmol/ml and Ala (2.45 nmol/ml. BCPM stored in 10% SW had shorter quality life compared to that stored in 5% salted whey.

  2. Changes in analytical and volatile compositions of red wines induced by pre-fermentation heat treatment of grapes.

    Science.gov (United States)

    Geffroy, Olivier; Lopez, Ricardo; Serrano, Eric; Dufourcq, Thierry; Gracia-Moreno, Elisa; Cacho, Juan; Ferreira, Vicente

    2015-11-15

    Experiments were carried out on Grenache, Carignan and Fer grapes in order to characterize the changes in nitrogen content of the musts, conventional enological parameters and aroma compounds of the wines induced by pre-fermentation heating of the grapes followed by alcoholic fermentation in liquid phase or in solid phase. In comparison to a standard vinification, we showed that a two-hour heat treatment at 70 °C induced a significant loss in several grape-derived aroma compounds (terpenols, norisoprenoids and some phenols) associated with an increase in α-terpineol, guaiacol and 2,6-dimethoxyphenol, which suggests thermal degradation. A significant increase in most of the ethyl esters, in acetates and in fatty acids were observed in wines fermented in liquid phase, together with a decrease in fusel alcohols. The substantial modification in the amino acid composition of the must seems to be a crucial element for the understanding of these changes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. EFFECTS OF CU AND SOLUTION HEAT TREATMENT ON THE MICROSTRUCTURE AND HARDNESS OF IN-SITU ALUMINIUM MATRIX COMPOSITE CONTAINING AL4SR PHASE

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    K. Tavighi

    2014-12-01

    Full Text Available This study was undertaken to investigate the effects of Cu and solution heat treatment on the microstructure and hardness of cast Al-Al4Sr metal matrix composite. Different amounts of Cu (0.3, 0.5, 1, 3 and 5 wt.% were added to the composite. Specimens were heat treated at 500 °C for 4 hours followed by water quenching. Microstructural studies were assessed by the use of optical microscope, scanning electron microscope (SEM and x-ray diffractometry (XRD. The results showed that addition of 5 wt.% Cu reduces the length of large needle-like Al4Sr phase and refines the microstructure. In addition, the presence of Cu-intermetallics increases hardness of the composite. Cu mainly forms θ phase which segregates at the grain boundaries. Heat treatment partially dissolves Cu-intermetallics and homogenizes the distribution of θ phase in the matrix.

  4. Influence of storage, heat treatment, and solids composition on the bleaching of whey with hydrogen peroxide.

    Science.gov (United States)

    Li, Xiaomeng E; Campbell, Rachel E; Fox, Aaron J; Gerard, Patrick D; Drake, MaryAnne

    2012-07-01

    The residual annatto colorant in liquid whey is bleached to provide a desired neutral color in dried whey ingredients. This study evaluated the influence of starter culture, whey solids and composition, and spray drying on bleaching efficacy. Cheddar cheese whey with annatto was manufactured with starter culture or by addition of lactic acid and rennet. Pasteurized fat-separated whey was ultrafiltered (retentate) and spray dried to 34% whey protein concentrate (WPC34). Aliquots were bleached at 60 °C for 1 h (hydrogen peroxide, 250 ppm), before pasteurization, after pasteurization, after storage at 3 °C and after freezing at -20 °C. Aliquots of retentate were bleached analogously immediately and after storage at 3 or -20 °C. Freshly spray dried WPC34 was rehydrated to 9% (w/w) solids and bleached. In a final experiment, pasteurized fat-separated whey was ultrafiltered and spray dried to WPC34 and WPC80. The WPC34 and WPC80 retentates were diluted to 7 or 9% solids (w/w) and bleached at 50 °C for 1 h. Freshly spray-dried WPC34 and WPC80 were rehydrated to 9 or 12% solids and bleached. Bleaching efficacy was measured by extraction and quantification of norbixin. Each experiment was replicated 3 times. Starter culture, fat separation, or pasteurization did not impact bleaching efficacy (P > 0.05) while cold or frozen storage decreased bleaching efficacy (P whey or 34% (w/w) protein liquid retentate (P whey. Optimization of whey bleaching conditions is important to reduce the negative effects of bleaching on the flavor of dried whey ingredients. This study established that liquid storage and whey composition are critical processing points that influence bleaching efficacy. © 2012 Institute of Food Technologists®

  5. A study on EMI shielding enhancement behaviors of Ni-plated CFs-reinforced polymer matrix composites by post heat treatment

    Science.gov (United States)

    Kim, Kwan-Woo; Han, Woong; Kim, Byoung-Suhk; Kim, Byung-Joo; An, Kay-Hyeok

    2017-09-01

    In order to develop the high quality electromagnetic interference shielding efficiency (EMI-SE) materials, Ni-plated carbon fiber fabrics (Ni-CFFs) were prepared by an electroless method. Effects of post heat-treatment conditions on EMI-SE and electrical conductivity of Ni-CFFs/epoxy composites were also investigated. The morphologies and structural properties of Ni-CFFs were measured by a SEM and a XRD. It was found that all the Ni peaks increased with increasing post-heat treatment temperature, indicating that some impurities were removed and nickel particle sharp crystalline peaks. Also, It was found that the EMI-SE of composites enhanced was increased after post heat-treatment. In the frequency range of electromagnetic wave occurred from appliances (3.0 × 107-6.0 × 108), EMI-SE of post-heat treatment Ni-CFs was increased. This result concludes that the EMI-SE of the composites can be enhanced according to the microstructure of Ni in the Ni-CFFs/epoxy composites.

  6. Heat treatment furnace

    Energy Technology Data Exchange (ETDEWEB)

    Seals, Roland D; Parrott, Jeffrey G; DeMint, Paul D; Finney, Kevin R; Blue, Charles T

    2014-10-21

    A furnace heats through both infrared radiation and convective air utilizing an infrared/purge gas design that enables improved temperature control to enable more uniform treatment of workpieces. The furnace utilizes lamps, the electrical end connections of which are located in an enclosure outside the furnace chamber, with the lamps extending into the furnace chamber through openings in the wall of the chamber. The enclosure is purged with gas, which gas flows from the enclosure into the furnace chamber via the openings in the wall of the chamber so that the gas flows above and around the lamps and is heated to form a convective mechanism in heating parts.

  7. Composite electrolytes of polyethylene glycol methyl ether and TiO{sub 2} for dye-sensitized solar cells-Effect of heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Akhtar, M. Shaheer, E-mail: shaheerakhtar@jbnu.ac.kr [School of Semiconductor and Chemical Engineering and Solar Energy Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); New and Renewable Energy Material Development Center (NewREC), Chonbuk National University (Korea, Republic of); Park, Jung-Guen; Kim, Ui-Yeon [School of Semiconductor and Chemical Engineering and Solar Energy Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Yang, O-Bong, E-mail: obyang@jbnu.ac.kr [School of Semiconductor and Chemical Engineering and Solar Energy Research Center, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); New and Renewable Energy Material Development Center (NewREC), Chonbuk National University (Korea, Republic of)

    2011-06-15

    Highlights: {yields} The heat treatment (80 deg. C) on prepared PEGME-TiO{sub 2} composite was essential step to improve the morphological and electrochemical properties. {yields} Raman spectra of PEGME-acid, PEGME-TiO{sub 2} and PEGME-TiO{sub 2}/80 deg. C composite electrolytes. {yields} PEGME-TiO{sub 2}/80 deg. C shows drastically increased strong peak (I{sub 3}{sup -} species) with a slight shifting at 113.1 cm{sup -1}. {yields} Indicates the significant increase of I{sub 3}{sup -} species in redox electrolytes upon heat treatment. - Abstract: For solid-state dye-sensitized solar cells (DSSCs), a composite electrolyte of polyethylene glycol methyl ether (PEGME) and titania (TiO{sub 2}) nanoparticles was prepared and characterized by Fourier transform-infra red (FT-IR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Raman spectroscopy. The heat treatment on PEGME and TiO{sub 2} composite was found to be an essential step to improve morphology, amorphicity and ionic conductivity of PEGME-TiO{sub 2} composite electrolytes. It was attributed to the increased bond strength of OC-O-Ti between PEGME and TiO{sub 2} and increased surface roughness of composite materials, which may help to absorb a large amount of iodide couple and effective generation of I{sub 3}{sup -} ions. A DSSC fabricated with heat treated PEGME-TiO{sub 2} composite electrolyte showed significantly enhanced overall conversion efficiency of 3.1%, which was 20% higher than that of the DSSC fabricated with bare PEGME-TiO{sub 2} composite electrolyte.

  8. High specific heat superconducting composite

    Science.gov (United States)

    Steyert, Jr., William A.

    1979-01-01

    A composite superconductor formed from a high specific heat ceramic such as gadolinium oxide or gadolinium-aluminum oxide and a conventional metal conductor such as copper or aluminum which are insolubly mixed together to provide adiabatic stability in a superconducting mode of operation. The addition of a few percent of insoluble gadolinium-aluminum oxide powder or gadolinium oxide powder to copper, increases the measured specific heat of the composite by one to two orders of magnitude below the 5.degree. K. level while maintaining the high thermal and electrical conductivity of the conventional metal conductor.

  9. Heat treatment deformations

    Energy Technology Data Exchange (ETDEWEB)

    Bavaro, A. (Soliveri SpA, Caravaggio (Italy))

    1990-02-01

    Types and causes of heat treatement derived isotropic and anisotropic dilatancies in ferrous materials are reviewed. The concepts are developed in such a way as to allow extension to all materials exhibiting martensitic tempering behaviour. This paper intends to illustrate the basic processes of dimensional variations undergone by the materials under heat treatments. The parametric analysis includes an analysis of the interactions amongst the parameters themselves. The relative importance of each parameter is assessed in order to determine methods to attenuate deformation action. Simplified examples are offered to provide technicians explanations as to why specific deformations occur and indications on improved materials working techniques.

  10. Influence of Heat-Treatment Temperature on the Physical Properties and Microstructure of Phosphoric Acid Coated Oxi-PAN Fiber/Phenolic Composites

    Energy Technology Data Exchange (ETDEWEB)

    Cho, D.H. [KUMHO NATIONAL UNIVERSITY OF TECHNOLOGY, KUMI (Korea, Republic of)

    1996-10-01

    Random OXI-PAN fiber/phenolic composites fabricated with uncoated and phosphoric acid coated OXI-PAN fibers were carbonized at various heat-treatment temperatures in an inert atmosphere. An effect of the presence or absence of phosphorous compound on the fiber surface in the composite after heat-treatment upon the physical properties and microstructure was studied. The physical properties of the two types of composite were explained in terms of microstructural behaviour and pore formation in the fiber, the matrix and the interface according to heat-treatment temperature. It was known that with increasing temperature the fiber/matrix interface becomes disappeared and shows a locally dense and indistinguishable phase due to possible chemical reaction between the fiber and the adjacent matrix. It was also noted that the phosphoric acid coating restraints the reduction of fiber diameter and increases the thermal stability under the carbonization condition so that it contributes somewhat to lower the volume shrinkage and to increase the carbon yield of the composite (author). 25 refs. figs.

  11. Effects of heat treatment on microstructure and mechanical properties of Ni60/h-BN self-lubricating anti-wear composite coatings on 304 stainless steel by laser cladding

    Science.gov (United States)

    Lu, Xiao-Long; Liu, Xiu-Bo; Yu, Peng-Cheng; Zhai, Yong-Jie; Qiao, Shi-Jie; Wang, Ming-Di; Wang, Yong-Guang; Chen, Yao

    2015-11-01

    Laser clad Ni60/h-BN self-lubricating anti-wear composite coating on 304 stainless steel were heat treated at 600 °C (stress relief annealing) for 1 h and 2 h, respectively. Effects of the phase compositions, microstructure, microhardness, nano-indentation and tribological properties of the composite coatings with and without heat treatment had been investigated systemically. Results indicated that three coatings mainly consist of the matrix γ-(Ni, Fe) solid solution, the CrB ceramic phases and the h-BN lubricating phases. The maximum microhardness of the coatings was first increased from 667.7 HV0.5 to 765.0 HV0.5 after heat treatment for 1 h, and then decreased to 698.3 HV0.5 after heat treatment for 2 h. The hardness of γ-(Ni, Fe) solid solution without heat treatment and after heat treatment 1 h and 2 h were 5.09 GPa, 7.20 GPa and 3.77 GPa, respectively. Compared with the coating without heat treatment, the friction coefficients of the coating after heat treatment were decreased obviously. Effects of the heat treatment time on friction coefficient were negligible, but were significant on wear volume loss. Comparatively speaking, the laser clad self-lubricating anti-wear composite coating after heat treatment for 1 h presented the best anti-wear and friction reduction properties.

  12. The effect of heat treatment on the magnitude and composition of residual gas in sealed silica glass ampoules

    Science.gov (United States)

    Palosz, W.; Szofran, F. R.; Lehoczky, S. L.

    1994-01-01

    The residual gas pressure and composition in sealed silica glass ampoules as a function of different treatment procedures has been investigated. The dependence of the residual gas on the outgassing and annealing parameters has been determined. The effects of the fused silica brand, of the ampoule fabrication, and of post-outgassing procedures have been evaluated.

  13. Effects of composition and heat treatment at 1150{degrees}C on creep-rupture properties of Fe{sub 3}Al-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    McKamey, C.G.; Maziasz, P.J.; Marrero-Santos, Y. [Oak Ridge National Lab., TN (United States)

    1995-08-01

    The effects of composition and heat treatment at 1150{degrees}C on the creep-rupture properties of Fe3Al-based alloys were studied. Tests of alloy FA-180 (Fe-28Al-5Cr-0.5Nb-0.8Mo-0.025Zr-0.05C-0.005B, at.%) with this heat treatment were performed in air using various test temperatures and stresses in order to obtain creep activation energies and constants. An activation energy for creep of approximately 150 kcal/mole was determined, a value which is approximately twice that obtained earlier for the binary alloy heat treated at 750{degrees}C. Tests were also conducted on alloys containing various combinations of Cr, Mo, Nb, Zr, C, and B in order to better understand the effect of composition on the improved creep resistance with heat treating at 1150{degrees}C. The results suggest an interaction of Mo with Zr and Nb to produce increased creep life.

  14. High Temperature Composite Heat Exchangers

    Science.gov (United States)

    Eckel, Andrew J.; Jaskowiak, Martha H.

    2002-01-01

    High temperature composite heat exchangers are an enabling technology for a number of aeropropulsion applications. They offer the potential for mass reductions of greater than fifty percent over traditional metallics designs and enable vehicle and engine designs. Since they offer the ability to operate at significantly higher operating temperatures, they facilitate operation at reduced coolant flows and make possible temporary uncooled operation in temperature regimes, such as experienced during vehicle reentry, where traditional heat exchangers require coolant flow. This reduction in coolant requirements can translate into enhanced range or system payload. A brief review of the approaches and challengers to exploiting this important technology are presented, along with a status of recent government-funded projects.

  15. Effects of heat treatment and formulation on the phase composition and chemical durability of the EBR-ll ceramic waste form.

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, W. E.; Dietz, N. L.; Janney, D. E.

    2006-01-31

    High-level radioactive waste salts generated during the electrometallurgical treatment of spent sodium-bonded nuclear fuel from the Experimental Breeder Reactor-II will be immobilized in a ceramic waste form (CWF). Tests are being conducted to evaluate the suitability of the CWF for disposal in the planned federal high-level radioactive waste repository at Yucca Mountain. In this report, the results of laboratory tests and analyses conducted to address product consistency and thermal stability issues called out in waste acceptance requirements are presented. The tests measure the impacts of (1) variations in the amounts of salt and binder glass used to make the CWF and (2) heat treatments on the phase composition and chemical durability of the waste form. A series of CWF materials was made to span the ranges of salt and glass contents that could be used during processing: between 5.0 and 15 mass% salt loaded into the zeolite (the nominal salt loading is 10.7%, and the process control range is 10.6 to 11.2 mass%), and between 20 and 30 mass% binder glass mixed with the salt-loaded zeolite (the nominal glass content is 25% and the process control range is 20 to 30 mass%). In another series of tests, samples of two CWF products made with the nominal salt and glass contents were reheated to measure the impact on the phase composition and durability: long-term heat treatments were conducted at 400 and 500 C for durations of 1 week, 4 weeks, 3 months, 6 months, and 1 year; short-term heat treatments were conducted at 600, 700, 800, and 850 C for durations of 4, 28, 52, and 100 hours. All of the CWF products that were made with different amounts of salt, zeolite, and glass and all of the heat-treated CWF samples were analyzed with powder X-ray diffraction to measure changes in phase compositions and subjected to 7-day product consistency tests to measure changes in the chemical durability. The salt loading had the greatest impact on phase composition and durability. A

  16. Magnetic carbon composites with a hierarchical structure for adsorption of tetracycline, prepared from sugarcane bagasse via hydrothermal carbonization coupled with simple heat treatment process.

    Science.gov (United States)

    Rattanachueskul, Natthanan; Saning, Amonrada; Kaowphong, Sulawan; Chumha, Nawapong; Chuenchom, Laemthong

    2017-02-01

    Sugarcane bagasse, an agricultural waste, was successfully converted into novel magnetic carbon composites by low temperature hydrothermal carbonization at 230°C for 24h, followed by heat treatment at 400°C for only 1h in air. Effects of NaOH and iron loading on the chemical properties of the composites were studied. In addition, various techniques were employed to investigate the physicochemical properties of the composites. Adsorption kinetics and isotherms were investigated with tetracycline (TC) for the magnetic composites. The magnetic carbon composite exhibited 48.35mg/g maximum adsorption capacity and was highly stable chemically and mechanically, with also good magnetic properties. The adsorption of TC by the magnetic adsorbent was mainly attributed to H-bonds and π-π interactions. The results indicate that waste sugarcane bagasse from the sugar industries can be efficiently transformed to a magnetic adsorbent for TC removal via a facile environmentally friendly method. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Effect of heat treatment on the efficient adsorption of Cd2+ ions by nanosized SiO2, TiO2 and their composite

    Science.gov (United States)

    Waseem, M.; Muntha, S. T.; Nawaz, M.; Rehman, W.; Rehman, M. A.; Shah, K. H.

    2017-01-01

    In this study nanosized SiO2, TiO2 and their composite were synthesized via the oil in water (o/w) microemulsion method and their thermal treatment was performed at 378, 573, 973 and 1273 K. The physicochemical properties of the samples were studied by surface area measurements, scanning electron microscopy, Fourier transform infra-red spectroscopy and x-ray diffraction analysis. The Brunauer, Emmett and Teller surface area of all the adsorbents increases from 378 to 573 K, while it decreases upon further heat treatment. The average crystallite size decreases by heating the samples from 378 to 573 K while it increases when the adsorbents were thermally heat treated at 973 and 1273 K. The intensity of a few IR bands was reduced along with the disappearance of most of the bands at higher temperatures. The appearance of the beta-cristobalite phase in SiO2 and the rutile phase in TiO2 was confirmed from the diffraction data. The heat treated samples were subjected to preliminary adsorption of Cd2+ ions from aqueous solution at 293 K. Based on the preliminary adsorption experiments, SiO2, TiO2 and their composite heat treated at 573 K were selected for further adsorption studies. The Langmuir model was found to be fitted to the sorption data of TiO2 and the nanocomposite while the adsorption of Cd2+ ions by the SiO2 nanoparticles was explained well based on the Freundlich model. In the present study, the maximum Cd2+ adsorption capacity of SiO2, TiO2 and their composite was found to be 79.72, 98.55 and 107.17 mg g-1, respectively. The q m and K f values obtained in the present study were found to be far better than those reported in the literature. The negative values of ΔG confirm the feasibility of an adsorption process at higher temperatures. The positive values of ΔH and ΔS represent the endothermic and physical nature of the adsorption process with the increased randomness of Cd2+ ions at the solid/solution interface.

  18. Change in Color and Volatile Composition of Skim Milk Processed with Pulsed Electric Field and Microfiltration Treatments or Heat Pasteurization

    Directory of Open Access Journals (Sweden)

    Anupam Chugh

    2014-04-01

    Full Text Available Non-thermal processing methods, such as pulsed electric field (PEF and tangential-flow microfiltration (TFMF, are emerging processing technologies that can minimize the deleterious effects of high temperature short time (HTST pasteurization on quality attributes of skim milk. The present study investigates the impact of PEF and TFMF, alone or in combination, on color and volatile compounds in skim milk. PEF was applied at 28 or 40 kV/cm for 1122 to 2805 µs, while microfiltration (MF was conducted using membranes with three pore sizes (lab-scale 0.65 and 1.2 µm TFMF, and pilot-scale 1.4 µm MF. HTST control treatments were applied at 75 or 95 °C for 20 and 45 s, respectively. Noticeable color changes were observed with the 0.65 µm TFMF treatment. No significant color changes were observed in PEF-treated, 1.2 µm TFMF-treated, HTST-treated, and 1.4 µm MF-treated skim milk (p ≥ 0.05 but the total color difference indicated better color retention with non-thermal preservation. The latter did not affect raw skim milk volatiles significantly after single or combined processing (p ≥ 0.05, but HTST caused considerable changes in their composition, including ketones, free fatty acids, hydrocarbons, and sulfur compounds (p < 0.05. The findings indicate that for the particular thermal and non-thermal treatments selected for this study, better retention of skim milk color and flavor components were obtained for the non-thermal treatments.

  19. INFLUENCE OF SILANE HEAT TREATMENT ON THE TENSILE BOND STRENGTH BETWEEN EX-3 SYNTHETIC VENEERING PORCELAIN AND COMPOSITE RESIN USING FIVE DIFFERENT ACTIVATION TEMPERATURES

    Directory of Open Access Journals (Sweden)

    Spartak Yanakiev

    2017-02-01

    Full Text Available Purpose: The purpose of the present study is to assess the effect of five different silane activation temperatures and eight activation methods on the tensile bond strength between one veneering porcelain and one composite resin material. Material and methods: A total of 81 ceramic rods were made of EX-3 veneering ceramic (Kuraray Noritake Dental, Japan. Sintered ceramic bars were grinded with diamond disks to size 10x2x2mm ± 0,05mm. The front part of each bar was polished. After ultrasonic cleaning in distilled water, the specimens were divided into nine groups. Silane was activated with air at room temperature, 38º С, 50º С, 100º С, 120º С using a custom made blow drier. In a silicone mold, a composite resin Z250 (3М ESPE, St. Paul, USA was condensed toward the bond ceramic surface. A total of 81 specimens approximately 2,0 cm long were prepared for tensile bond testing. One way ANOVA, followed by Bonferroni and Games-Howell tests were used for statistical analysis. Results: The lowest tensile bond strength was observed in the control group (3,51MPa. Group 2 yielded the highest bond strength among all groups (19,54MPa. Silane heat treatment enhanced the bond strength for all treatment methods. Within the polished specimens, the highest bond strength was yielded with warm air at 120ºС (11,31MPa. Conclusion: The most effective method for bonding Z250 composite resin to EX-3 veneering ceramic includes HF etching, silane, and adhesive resin. The most effective heat treatment method for bonding is hot air at 120ºС.

  20. Effect of Heat Treatment on The Crystal Structur, Electrical Conductivity and Surface of Ba1.5Sr0.5Fe2O5 Composite

    Science.gov (United States)

    Purwanto, P.; Adi, WA; Yunasfi

    2017-05-01

    The Composite of Ba1,5Sr0,5Fe2O5 has been synthesized by using powder metallurgy technique. The Ba1.5Sr0.5Fe2O5 were prepared from BaCO3, SrCO3 and Fe2O3 raw materials with a specific weight ratio. The three materials were synthesized by powder metallurgy under heat treatment at 800 °C, 900 °C, and 1000 °C for 5 hours. All the three samples were characterized by using X-ray Diffraction (XRD) to determine the crystal structure and crystal size, LCR meter to determine the conductivity, and Scanning Electron Microscope (SEM) to observe the morphological of the composites. The phase analysis result showed that the composite consists of several minor phases such as BaO2, SrO2, and Fe2O3. The Crystal size of composite Ba1.5Sr0.5Fe2O5 decreased while increases the strain of crystal with increasing of sintering temperature. The crystal size of the Ba1.5Sr0.5Fe2O5 composite is 3.55 nm to 7.23 nm and value of strain is 8.47% until 3.90%. Based on the conductivity measurement, it was obtained that the conductivity of the Ba1.5Sr0.5Fe2O5 composite decreased with increasing sintering temperature. It was also noticed that the conductivity increased with increasing of frequency. The conductivity ranged from 6.619×10-7 S/cm to 65.659×10-7 S/cm. The energy dispersive spectroscopy (EDS) analysis showed that several dominant elements were a good agreement with the phase analysis.

  1. Prestorage Heat Treatment of Apples

    National Research Council Canada - National Science Library

    Skrzyński, Jan

    2007-01-01

    .... The main effect of heat treatment was total reduction of fruit spoilage due to storage diseases, whereas non treated fruits were affected by bitter rot (Gloeosporium), gray mold (Botrytis) and blue mold (Penicillium) respectively...

  2. Effects of Heat Treatment on the Tribological Properties of Sicp/Al-5Si-1Cu-0.5Mg Composite Processed by Electromagnetic Stirring Method

    Directory of Open Access Journals (Sweden)

    Ning Li

    2018-03-01

    Full Text Available This paper investigated the influence of heat treatment (T6 on the dry sliding wear behavior of SiCp/Al-5Si-1Cu-0.5Mg composite that was fabricated by electromagnetic stirring method. The wear rates and friction coefficients were measured using a pin-on-disc tribometer under loads of 15–90 N at dry sliding speeds of 100 r/min, 200 r/min, and 300 r/min, over a sliding time of 15 min. The worn surfaces and debris were examined using a scanning electron microscope and was analyzed with an energy dispersive spectrometer. The experimental results revealed that SiCp/Al-5Si-1Cu-0.5Mg alloy treated with T6 exhibited lower wear rate and friction coefficient than the other investigated alloys. As the applied load increased, the wear rate and friction coefficient increased. While, the wear rate and friction coefficient decreased with the sliding speed increasing. The morphology of the eutectic silicon was spheroidal after the T6 heat treatment. SiCp particles and Al2Cu phase can be considered as the main raisons for improving the wear behavior. Abrasion and oxidation were the wear mechanisms at low load levels. However, the wear mechanisms at high load levels were plastic deformation and delamination.

  3. Production of AA2124/MoSi2/25p composites and effect of heat treatment on their microstructure, hardness and compression properties

    Directory of Open Access Journals (Sweden)

    Piyadeh, Fatemeh

    2014-12-01

    Full Text Available AA2124/25vol%MoSi2 composites were processed by two powder metallurgy routes: high energy ball milling of the reinforcement and alloy powder (B composite and wet blending with cyclohexane (W composite, both followed by extrusion to achieve full consolidation. As-extruded and heat treated composite bars were studied microstructurally and mechanically (hardness and compression tests under quasistatic loading. Microstructure and fracture profiles were observed by scanning electron microscopy and the reaction products formed in the matrix were identified by energy-dispersive X-ray spectroscopy and X-ray diffraction analysis. The results show that for both composites, the hardness of the specimens in solution and aged condition was higher than in the as-extruded condition. The hardness of the B composite was higher than that of the W composite whereas the age-hardenability of the B composite was significantly lower than that of the W composite. After heat treatments, small diffusion reaction phases appeared at the interface between matrix and reinforcements. Compressive yield strength and the ultimate strength of both composites improved considerably after the artificial ageing. The composite fracture surfaces exhibited microscopically a ductile appearance that consisted of dimples in the matrix and a fragile fracture of the MoSi2 particulates.En este trabajo se procesaron materiales compuestos AA2124/25vol% MoSi2 mediante dos rutas pulvimetalúrgicas: mezcla de refuerzo y matriz mediante molino de bolas de alta energía (compuesto B y mezcla húmeda con ciclohexano (compuesto W. Ambos polvos compuestos se consolidaron por extrusión. Los materiales recién extruidos y después de tratados térmicamente se estudiaron desde el punto de vista microestructural y mecánico (dureza y compresión bajo carga cuasiestática. Las microestructuras y los perfiles de fractura se observaron por microscopía electrónica de barrido y los productos de reacci

  4. Fabrication of Na0.7MnO2/C composite cathode material by simple heat treatment for high-power na-ion batteries

    Science.gov (United States)

    Sohn, DongRak; Lim, Sung-Jin; Nam, Do-Hwan; Hong, Kyung-Sik; Kim, Tae-Hee; Oh, SeKwon; Eom, Ji-Yong; Cho, EunAe; Kwon, HyukSang

    2018-01-01

    A Na0.7MnO2/C composite cathode material is synthesized by simple and costeffective two-step heat treatment for an improvement in the rate capability of Na0.7MnO2. The first heat treatment is to synthesize Na0.7MnO2, and the second one is a low temperature annealing at 350 °C for 1 h in air, which is necessary to suppress an interfacial reaction between the Na0.7MnO2 and C in the synthesis process of Na0.7MnO2/C composite. Structural analyses by XRD and XPS reveal that the Na0.7MnO2/C shows the same structural properties as that of the pristine Na0.7MnO2, and hence they exhibit the same initial discharge capacity of 175 mAh g-1 at 20 mA g-1. At a current density of 400 mA g-1, the discharge capacity of Na0.7MnO2 reduces to 50 mAh g-1 (28% of the initial discharge capacity), whereas that of Na0.7MnO2/C reduces to 108 mAh g-1 (61% of the initial discharge capacity). The enhanced rate capability of the Na0.7MnO2/C is attributed to the conductive carbon layer formed on the surface of Na0.7MnO2 particles, enabling the facile transport of electrons from the current collector to the surface of the Na0.7MnO2 particles. [Figure not available: see fulltext.

  5. Heat Generation by Irradiated Complex Composite Nanostructures

    DEFF Research Database (Denmark)

    Ma, Haiyan; Tian, Pengfei; Pello, Josselin

    2014-01-01

    Heating of irradiated metallic e-beam generated nanostructures was quantified through direct measurements paralleled by novel model-based numerical calculations. By comparing discs, triangles, and stars we showed how particle shape and composition determines the heating. Importantly, our results...

  6. Composite heat damage spectroscopic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Janke, C.J.; Muhs, J.D.; Wachter, E.A.; Ziegler, R.E. (Oak Ridge National Lab., TN (USA)); Powell, G.L.; Smyrl, N.R. (Oak Ridge Y-12 Plant, TN (USA)); Philpot, H.E. (Oak Ridge Gaseous Diffusion Plant, TN (USA))

    1990-09-01

    The Oak Ridge National Laboratory/Applied Technology Division (ORNL/ATD) has successfully demonstrated the unique applicability of two spectroscopic techniques that possess the capability of detecting heat damage in IM6/3501-6 laminates and correlation of this damage with the residual mechanical-strength properties. The results on the diffuse reflectance infrared fourier transform (DRIFT) and laser-pumped fluorescence (LPF) spectroscopic techniques, which are capable of rapid, in-service, non-destructive detection and quantitation of heat damage in IM6/3501-6 laminates, is presented. Both of these techniques have been shown to be quite effective at probing the elusive and complex molecular changes that take place in IM6/3501-6 laminates subjected to varying degrees of thermal degradation. Using LPF or DRIFT techniques, it has been shown that laminates having different thermal histories can be readily differentiated from one another due to their characteristic fingerprint'' spectral features. The effects of short-term, elevated temperature heating on the room- temperature compressive interlaminar-shear, and flexural strengths and room-temperature shore-D hardness properties of dry'' and wet'' preconditioned IM6/3501-6 laminates are discussed. Additionally, the geometrical changes and percent-weight-loss measurements of IM6/3501-6 laminates that accompany heat damage are also examined. It was found that below a certain temperature/time exposure threshold, these laminates visually and microscopically appeared to be undamaged but, in fact, may have lost a significant percentage of their original strength. In addition, laminates that were exposed above the temperature/time exposure threshold suffered dramatic geometrical changes and large amounts of weight loss. 32 refs., 39 figs., 10 tabs.

  7. Pre-heating mitigates composite degradation

    Directory of Open Access Journals (Sweden)

    Jessika Calixto da SILVA

    2015-12-01

    Full Text Available ABSTRACT Dental composites cured at high temperatures show improved properties and higher degrees of conversion; however, there is no information available about the effect of pre-heating on material degradation. Objectives This study evaluated the effect of pre-heating on the degradation of composites, based on the analysis of radiopacity and silver penetration using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS. Material and Methods Thirty specimens were fabricated using a metallic matrix (2x8 mm and the composites Durafill VS (Heraeus Kulzer, Z-250 (3M/ESPE, and Z-350 (3M/ESPE, cured at 25°C (no pre-heating or 60°C (pre-heating. Specimens were stored sequentially in the following solutions: 1 water for 7 days (60°C, plus 0.1 N sodium hydroxide (NaOH for 14 days (60°C; 2 50% silver nitrate (AgNO3 for 10 days (60°C. Specimens were radiographed at baseline and after each storage time, and the images were evaluated in gray scale. After the storage protocol, samples were analyzed using SEM/EDS to check the depth of silver penetration. Radiopacity and silver penetration data were analyzed using ANOVA and Tukey’s tests (α=5%. Results Radiopacity levels were as follows: Durafill VSZ-350>Z-250 (p<0.05. After storage in water/NaOH, pre-heated specimens presented higher radiopacity values than non-pre-heated specimens (p<0.05. There was a lower penetration of silver in pre-heated specimens (p<0.05. Conclusions Pre-heating at 60°C mitigated the degradation of composites based on analysis of radiopacity and silver penetration depth.

  8. Effect of chemical compositions and heat treatment on IGSCC resistance for strain hardened low carbon austenitic stainless steels in oxygenated water

    Energy Technology Data Exchange (ETDEWEB)

    Yonezawa, T. [FRRI, Graduate School of Engineering, Tohoku University (Japan); Kanasaki, H.; Fujimoto, K.; Taneike, M. [Takasago R-D Center, Mitsubishi Heavy Industries (Japan); Ooki, S.; Sueishi, Y.; Tezuka, H.; Takamori, K.; Suzuki, S. [Materials Engineering Center, R-D Center, Tokyo Electric Power Company (Japan)

    2011-07-01

    In order to develop the highly resistant alternative materials to intergranular stress corrosion cracking (IGSCC) for the non-sensitized and strain hardened low carbon austenitic stainless steel in oxygenated water, the effects of chemical compositions and heat treatment conditions on the IGSCC resistance and stacking fault energy (SFE) values were studied for 33 laboratory melted steels and commercial type 310S stainless steel. The IGSCC resistance for test materials was compared by the maximum crack length, average crack length and cracked area in fatigue pre-cracked CT specimens after SCC test in oxygenated high temperature water. SFE values for these test materials were measured by the transmission electron microscopy on the width of isolated extended dislocations under g-3g weak beam condition for thin foils taken from the test materials, in this study. From these experiments, the effects of the chromium, molybdenum, nitrogen, silicon and manganese contents on the SCC resistance for non-aged materials were not so pronounced in this study. It is strongly suggested that the SFE value is a key parameter for the IGSCC resistance of the aged or non-aged and strain hardened low carbon austenitic stainless steels. (authors)

  9. Pre-heating mitigates composite degradation.

    Science.gov (United States)

    Silva, Jessika Calixto da; Rogério Vieira, Reges; Rege, Inara Carneiro Costa; Cruz, Carlos Alberto dos Santos; Vaz, Luís Geraldo; Estrela, Carlos; Castro, Fabrício Luscino Alves de

    2015-01-01

    Dental composites cured at high temperatures show improved properties and higher degrees of conversion; however, there is no information available about the effect of pre-heating on material degradation. Objectives This study evaluated the effect of pre-heating on the degradation of composites, based on the analysis of radiopacity and silver penetration using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). Material and Methods Thirty specimens were fabricated using a metallic matrix (2x8 mm) and the composites Durafill VS (Heraeus Kulzer), Z-250 (3M/ESPE), and Z-350 (3M/ESPE), cured at 25°C (no pre-heating) or 60°C (pre-heating). Specimens were stored sequentially in the following solutions: 1) water for 7 days (60°C), plus 0.1 N sodium hydroxide (NaOH) for 14 days (60°C); 2) 50% silver nitrate (AgNO3) for 10 days (60°C). Specimens were radiographed at baseline and after each storage time, and the images were evaluated in gray scale. After the storage protocol, samples were analyzed using SEM/EDS to check the depth of silver penetration. Radiopacity and silver penetration data were analyzed using ANOVA and Tukey's tests (α=5%). Results Radiopacity levels were as follows: Durafill VSZ-350>Z-250 (pheated specimens presented higher radiopacity values than non-pre-heated specimens (pheated specimens (pheating at 60°C mitigated the degradation of composites based on analysis of radiopacity and silver penetration depth.

  10. Heat treatment of milk and its importance

    OpenAIRE

    VOČADLOVÁ, Kateřina

    2016-01-01

    The aim of this work is to assess the public knowledge of heat treatment, its purpose and effect on milk quality and to find out their attitude to raw milk consumption. Heat treatment of milk is a commonly used part of dairy processing. Although the heat treatment has a significant impact on ensuring microbial quality, safety and shelf life of milk, its application still face a public disagreement, primary in connection with potential health benefits, which are lost during heat treatment. The...

  11. Heat Treatment Procedure Qualification for Steel Castings

    Energy Technology Data Exchange (ETDEWEB)

    Mariol Charles; Nicholas Deskevich; Vipin Varkey; Robert Voigt; Angela Wollenburg

    2004-04-29

    Heat treatment practices used by steel foundries have been carefully studied as part of comprehensive heat treatment procedure qualification development trials. These studies highlight the relationships between critical heat treatment process control parameters and heat treatment success. Foundry heat treatment trials to develop heat treatment procedure qualifications have shed light on the relationship between heat treatment theory and current practices. Furnace load time-temperature profiles in steel foundries exhibit significant differences depending on heat treatment equipment, furnace loading practice, and furnace maintenance. Time-temperature profiles of furnace control thermocouples can be very different from the time-temperature profiles observed at the center of casting loads in the furnace. Typical austenitization temperatures and holding times used by steel foundries far exceed what is required for transformation to austenite. Quenching and hardenability concepts were also investigated. Heat treatment procedure qualification (HTPQ) schema to demonstrate heat treatment success and to pre-qualify other alloys and section sizes requiring lesser hardenability have been developed. Tempering success is dependent on both tempering time and temperature. As such, furnace temperature uniformity and control of furnace loading during tempering is critical to obtain the desired mechanical properties. The ramp-up time in the furnace prior to the establishment of steady state heat treatment conditions contributes to the extent of heat treatment performed. This influence of ramp-up to temperature during tempering has been quantified.

  12. Heat Treatment Procedure Qualification for Steel Castings

    Energy Technology Data Exchange (ETDEWEB)

    Voigt, Robert C. [Pennsylvania State Univ., University Park, PA (United States); Charles, Mariol [Pennsylvania State Univ., University Park, PA (United States); Deskevich, Nicholas [Pennsylvania State Univ., University Park, PA (United States); Varkey, Vipin [Pennsylvania State Univ., University Park, PA (United States); Wollenburg, Angela [Pennsylvania State Univ., University Park, PA (United States)

    2004-10-15

    Heat treatment practices used by steel foundries have been carefully studied as part of comprehensive heat treatment procedure qualification development trials. These studies highlight the relationships between critical heat treatment process control parameters and heat treatment success. Foundry heat treatment trials to develop heat treatment procedure qualifications have shed light on the relationship between heat treatment theory and current practices. Furnace load time-temperature profiles in steel foundries exhibit significant differences depending on heat treatment equipment, furnace loading practice, and furnace maintenance. Time-temperature profiles of furnace control thermocouples can be very different from the time-temperature profiles observed at the center of casting loads in the furnace. Typical austenitization temperatures and holding times used by steel foundries far exceed what is required for transformation to austenite. Quenching and hardenability concepts were also investigated. Heat treatment procedure qualification (HTPQ) schema to demonstrate heat treatment success and to pre-qualify other alloys and section sizes requiring lesser hardenability have been developed. Tempering success is dependent on both tempering time and temperature. As such, furnace temperature uniformity and control of furnace loading during tempering is critical to obtain the desired mechanical properties. The ramp-up time in the furnace prior to the establishment of steady state heat treatment conditions contributes to the extent of heat treatment performed. This influence of ramp-up to temperature during tempering has been quantified.

  13. 29 CFR 1919.36 - Heat treatment.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Heat treatment. 1919.36 Section 1919.36 Labor Regulations...) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons § 1919.36 Heat treatment. (a) The annealing of wrought iron gear required by this part shall be...

  14. 29 CFR 1919.80 - Heat treatment.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Heat treatment. 1919.80 Section 1919.80 Labor Regulations...) GEAR CERTIFICATION Certification of Shore-Based Material Handling Devices § 1919.80 Heat treatment. (a) Wherever heat treatment of any loose gear is recommended by the manufacturer, it shall be carried out in...

  15. Hypersonic Composites Resist Extreme Heat and Stress

    Science.gov (United States)

    2007-01-01

    Through research contracts with NASA, Materials and Electrochemical Research Corporation (MER), of Tucson, Arizona, contributed a number of technologies to record-breaking hypersonic flights. Through this research, MER developed a coating that successfully passed testing to simulate Mach 10 conditions, as well as provide several additional carbon-carbon (C-C) composite components for the flights. MER created all of the leading edges for the X-43A test vehicles at Dryden-considered the most critical parts of this experimental craft. In addition to being very heat resistant, the coating had to be very lightweight and thin, as the aircraft was designed to very precise specifications and could not afford to have a bulky coating. MER patented its carbon-carbon (C-C) composite process and then formed a spinoff company, Frontier Materials Corporation (FMC), also based in Tucson. FMC is using the patent in conjunction with low-cost PAN (polyacrylonitrile)-based fibers to introduce these materials to the commercial markets. The C-C composites are very lightweight and exceptionally strong and stiff, even at very high temperatures. The composites have been used in industrial heating applications, the automotive and aerospace industries, as well as in glass manufacturing and on semiconductors. Applications also include transfer components for glass manufacturing and structural members for carrier support in semiconductor processing.

  16. Polymer composites prepared from heat-treated starch and styrene-butadiene latex

    Science.gov (United States)

    Thermoplastic starch/latex polymer composites were prepared using styrene–butadiene (SB) latex and heat-treated cornstarch. The composites were prepared in a compression mold at 130 °C, with starch content 20%. An amylose-free cornstarch, waxy maize, was used for this research and the heat treatment...

  17. Heat release rate of wood-plastic composites

    Science.gov (United States)

    N. M. Stark; R. H. White; C. M. Clemons

    1997-01-01

    Wood-plastic composites are becoming more important as a material that fulfills recycling needs. In this study, fire performance tests were conducted on several compositions of wood and plastic materials using the Ohio State University rate of heat release apparatus. Test results included five-minute average heat release rate in kW/m2 (HRR avg) and maximum heat release...

  18. MODELLING OF HEAT CONDUCTIVITY OF COMPOSITE MATERIALS WITH BALL INCLUSIONS

    Directory of Open Access Journals (Sweden)

    V. Pugachev Oleg

    2017-01-01

    Full Text Available A number of papers deals with the heat conductivity of composite materials: Zarubin et al used new approaches to the problem of evaluation of the effective heat conductivity coefficients of composite material with ball inclusions. We used variational analysis for a simplified model in a vicinity of inclusion. Contemporary computers allow implementing another approach to solving the problem of the effective heat conductivity: it may be modelled by the Brownian motion of virtual heat particles. The main idea is to obtain the exact formula for the heat conductivity for a homogeneous material and subsequently obtain a statistical evaluation of this formula for a composite material.In the present paper we compare two methods for finding the effective heat conductivity coefficients of composite materials by modeling the process of heat conduction via the Brownian motion of virtual heat particles. We consider a composite with ball inclusions of a material with heat conductivity and heat capacity coefficientsdiffering from those of the matrix material. In a computational experiment, we simulate the process of heatconduction through a flat layer of the composite material, which has been heated on one side at the initial moment. In order to find the confidence interval for the effective heat conductivity coefficient, we find, by means of statistics, either the displacement of the center of heat energy, or the probability of a virtual particle to pass through the layer during a certain time. We compare our results with theoretical assessments suggested by other authors.

  19. 29 CFR 1919.16 - Heat treatment.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Heat treatment. 1919.16 Section 1919.16 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) GEAR CERTIFICATION Certification of Vessels' Cargo Gear § 1919.16 Heat treatment. (a) All chains (other...

  20. Effects of heat treatment on deformation characteristics of medium ...

    African Journals Online (AJOL)

    The effects of heat treatment on bending deformation, tensile strength and hardness of RST 37 medium carbon steels were investigated. Steel rod samples of ø12 mm diameter, 100 mm length, and % weight composition of 0.39 wt % C, 0.70 wt % Mn and 0.80 wt % Si and traces of alloying elements were tested.

  1. Effects of moisture content and heat treatment on peroxide value ...

    African Journals Online (AJOL)

    Effects of moisture content and heat treatment on peroxide value and oxidative stability of un-refined sesame oil. ... Its seed contains about 42-54 % quality oil, 22-25 % protein, 20-25 % carbohydrates and 4-6% ash. This composition varies with genetic ... and temperature. Key words: Sesame, Oil, Crude, Oxidation, Storage ...

  2. An Energy Savings Model for the Heat Treatment of Castings

    Energy Technology Data Exchange (ETDEWEB)

    Y. Rong; R. Sisson; J. Morral; H. Brody

    2006-12-31

    An integrated system of software, databases, and design rules have been developed, verified, and to be marketed to enable quantitative prediction and optimization of the heat treatment of aluminum castings to increase quality, increase productivity, reduce heat treatment cycle times and reduce energy consumption. The software predicts the thermal cycle in critical locations of individual components in a furnace, the evolution of microstructure, and the attainment of properties in heat treatable aluminum alloy castings. The model takes into account the prior casting process and the specific composition of the component. The heat treatment simulation modules can be used in conjunction with software packages for simulation of the casting process. The system is built upon a quantitative understanding of the kinetics of microstructure evolution in complex multicomponent alloys, on a quantitative understanding of the interdependence of microstructure and properties, on validated kinetic and thermodynamic databases, and validated quantitative models.

  3. Rapid Heat Treatment of Aluminum High-Pressure Diecastings

    Science.gov (United States)

    Lumley, R. N.; Polmear, I. J.; Curtis, P. R.

    2009-07-01

    Recently, it has been demonstrated that common high-pressure diecasting (HPDC) alloys, such as those based on the Al-Si-Cu and Al-Si-Mg-(Cu) systems, may be successfully heat treated without causing surface blistering or dimensional instability. In some compositions, the capacity to exploit age hardening may allow the proof stress values to be doubled when compared to the as-cast condition. This heat treatment procedure involves the use of severely truncated solution treatment cycles conducted at lower than normal temperatures, followed by quenching and natural or artificial aging. The potential therefore exists to develop and evaluate secondary HPDC alloys designed specifically for rapid heat treatment, while still displaying high castability. This article reports results of an experimental program in which responses of various alloy compositions to age hardening have been investigated with the primary aim of further reducing the duration and cost of the heat treatment cycle while maintaining high tensile properties. Composition ranges have been established for which values of 0.2 pct proof stress exceeding 300 MPa ( i.e., increases of ~100 pct above as-cast values) can be achieved using a procedure that involves a total time for solution treatment plus age hardening of only 30 minutes. This rapid aging behavior is shown to be related to precipitation of the complex Q' phase, which forms primarily when Mg contents of the alloys are above ~0.2 wt pct.

  4. MATHEMATICAL MODELING OF HEATING RATE PRODUCT AT HIGH HEAT TREATMENT

    Directory of Open Access Journals (Sweden)

    M. M. Akhmedova

    2014-01-01

    Full Text Available Methods of computing and mathematical modeling are all widely used in the study of various heat exchange processes that provide the ability to study the dynamics of the processes, as well as to conduct a reasonable search for the optimal technological parameters of heat treatment.This work is devoted to the identification of correlations among the factors that have the greatest effect on the rate of heating of the product at hightemperature heat sterilization in a stream of hot air, which are chosen as the temperature difference (between the most and least warming up points and speed cans during heat sterilization.As a result of the experimental data warming of the central and peripheral layers compote of apples in a 3 liter pot at high-temperature heat treatment in a stream of hot air obtained by the regression equation in the form of a seconddegree polynomial, taking into account the effects of pair interaction of these parameters. 

  5. Influence of age and formalin treatment on the chemical composition ...

    African Journals Online (AJOL)

    The chemical composition and in vitro dry-matter digestibility (IVDMD) of manure collected from steers fed ... Formalin treatment under these conditions negatively influenced the chemical composition and IVDMD of these parameters with respect to nutritive value. .... value comparable to that of heat-damaged haylage.

  6. Heat Pre-Treatment of Beverages Wastewater on Hydrogen Production

    Science.gov (United States)

    Uyub, S. Z.; Mohd, N. S.; Ibrahim, S.

    2017-06-01

    At present, a large variety of alternative fuels have been investigated and hydrogen gas is considered as the possible solution for the future due to its unique characteristics. Through dark fermentation process, several factors were found to have significant impact on the hydrogen production either through process enhancement or inhibition and degradation rates or influencing parameters. This work was initiated to investigate the optimum conditions for heat pre-treatment and initial pH for the dark fermentative process under mesophilic condition using a central composite design and response surface methodology (RSM). Different heat treatment conditions and pH were performed on the seed sludge collected from the anaerobic digester of beverage wastewater treatment plant. Heat treatment of inoculum was optimized at different exposure times (30, 90, 120 min), temperatures (80, 90 and 100°C) and pH (4.5, 5.5, 6.5) in order to maximize the biohydrogen production and methanogens activity inhibition. It was found that the optimum heat pre-treatment condition and pH occurred at 100°C for 50 min and the pH of 6.00. At this optimum condition the hydrogen yield was 63.0476 ml H2/mol glucose (H2 Yield) and the COD removal efficiency was 90.87%. In conclusion, it can be hypothesized that different heat treatment conditions led to differences in the initial microbial communities (hydrogen producing bacteria) which resulted in the different hydrogen yields.

  7. Fatigue and frictional heating in ceramic matrix composites

    DEFF Research Database (Denmark)

    Jacobsen, T.K.; Sørensen, B.F.; Brøndsted, P.

    1997-01-01

    This paper describes an experimental technique for monitoring the damage evolution in ceramic matrix composites during cyclic testing. The damage is related to heat dissipation, which may be measured as radiated heat from the surface of the test specimen. In the present experimental set-up an iso......This paper describes an experimental technique for monitoring the damage evolution in ceramic matrix composites during cyclic testing. The damage is related to heat dissipation, which may be measured as radiated heat from the surface of the test specimen. In the present experimental set......-up an isothermal chamber has been utilized. The chamber walls and the grips are water-cooled to allow a consistent calculation of the conductive heat loss to the grips, the radiative heat loss to the chamber walls, and the convective heat loss to the air. An infrared camera scans the surface continously...

  8. Study on the heat-resistant EB curing composites

    Energy Technology Data Exchange (ETDEWEB)

    Bao Jianwen; Li Yang [Institute of Aeronautical Materials, Beijing (China); Li Fengmei [Institute of Low Energy Nuclear Physics, Beijing Normal Univ., Beijing (China)

    2000-03-01

    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)

  9. Wide-angle X-ray scattering study of heat-treated PEEK and PEEK composite

    Science.gov (United States)

    Cebe, Peggy; Lowry, Lynn; Chung, Shirley Y.; Yavrouian, Andre; Gupta, Amitava

    1987-01-01

    Samples of poly(etheretherketone) (PEEK) neat resin and APC-2 carbon fiber composite were subjected to various heat treatments, and the effect of quenching and annealing treatments was studied by wide-angle X-ray scattering. It is found that high-temperature treatments may introduce disorder into neat resin and composite PEEK when followed by rapid cooling. The disorder is metastable and can revert to ordered state when the material is heated above its glass transition temperature and then cooled slowly. The disorder may result from residual thermal stresses.

  10. Heat Stress in Dairy Cattle Alters Lipid Composition of Milk.

    Science.gov (United States)

    Liu, Z; Ezernieks, V; Wang, J; Arachchillage, N Wanni; Garner, J B; Wales, W J; Cocks, B G; Rochfort, S

    2017-04-19

    Heat stress, potentially affecting both the health of animals and the yield and composition of milk, occurs frequently in tropical, sub-tropical and temperate regions. A simulated acute heat stress experiment was conducted in controlled-climate chambers and milk samples collected before, during and after the heat challenge. Milk lipid composition, surveyed using LC-MS, showed significant changes in triacylglycerol (TAG) and polar lipid profiles. Heat stress (temperature-humidity index up to 84) was associated with a reduction in TAG groups containing short- and medium-chain fatty acids and a concomitant increase in those containing long-chain fatty acids. The abundance of five polar lipid classes including phosphatidylethanolamine, phosphatidylserine, phosphatidylcholine, lysophosphatidylcholine and glucosylceramide, was found to be significantly reduced during heat stress. Lysophosphatidylcholine, showing the greatest reduction in concentration, also displayed a differential response between heat tolerant and heat susceptible cows during heat stress. This phospholipid could be used as a heat stress biomarker for dairy cattle. Changes in TAG profile caused by heat stress are expected to modify the physical properties of milk fat, whereas the reduction of phospholipids may affect the nutritional value of milk. The results are discussed in relation to animal metabolism adaptation in the event of acute heat stress.

  11. Influence of Ear Surface Area on Heat Tolerance of Composite ...

    African Journals Online (AJOL)

    Relative importance of ear surface area on heat tolerance of composite rabbit population was evaluated. The study was conducted during the dry and rainy seasons, climatic data were recorded to obtain categorical heat stress index. Physiological parameters, growth performance, ear length and ear width of the rabbits ...

  12. effects of heat input on the chemical composition and hardness

    African Journals Online (AJOL)

    2012-07-02

    Jul 2, 2012 ... This study examines the thermochemical reactions which alter weld metal chemistry by applying the arc heat ... Keywords: alloying element, brinell hardness number (BHN), chemical composition, heat input, thermochemical reaction ..... national Journal of Advances in Science and Tech- nology, Vol.

  13. 49 CFR 179.500-6 - Heat treatment.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Heat treatment. 179.500-6 Section 179.500-6...-6 Heat treatment. (a) Each necked-down tank shall be uniformly heat treated. Heat treatment shall... treatment of alternate steels shall be approved. All scale shall be removed from outside of tank to an...

  14. Effects of heat treatment on the hierarchical porous structure and electro-capacitive properties of RuO{sub 2}/activated carbon nanofiber composites

    Energy Technology Data Exchange (ETDEWEB)

    Jun, Ye Ri; Kim, Bo Hye [Div. of Science Education, Chemistry Education Major, Daegu University, Daegu (Korea, Republic of)

    2016-11-15

    Electrochemical capacitors based on hierarchical porous activated carbon nanofiber (RuO{sub 2} /ACNF) composites are fabricated by one-step electrospinning, and then stabilized at different activation temperatures. The effect of the activation temperature on the structural properties and electrochemical behavior of the RuO{sub 2} /ACNF composites is intensively investigated in 6 M KOH electrolyte. The RuO{sub 2} /ACNF-800 composites activated at high temperature possess abundant mesopores and larger pores, which improve the electrochemical performance, especially at high charge–discharge rates. The energy storage capabilities of the RuO{sub 2} /ACNF-800 electrode prepared at high temperature are as follows: a maximum specific capacitance of 150 F/g and an energy density of 14–20 Wh/kg in the respective power density range of 400 to 10 000 W/kg in an aqueous solution. Furthermore, this electrode exhibits high-rate electrochemical performance with a specific capacitance reduction of less than 28% of the initial value at a discharge current of 20 mA/cm{sup 2}. Therefore, the hierarchical porous RuO{sub 2} /ACNF composites with well-developed mesoporous structure provide low resistance for charge diffusion and a short pathway for ion transportation, yielding good capacitive behavior.

  15. In situ heat treatment process utilizing a closed loop heating system

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Nguyen, Scott Vinh (Houston, TX)

    2010-12-07

    Systems and methods for an in situ heat treatment process that utilizes a circulation system to heat one or more treatment areas are described herein. The circulation system may use a heated liquid heat transfer fluid that passes through piping in the formation to transfer heat to the formation. In some embodiments, the piping may be positioned in at least two of the wellbores.

  16. Influence of heat processing methods on the nutrient composition ...

    African Journals Online (AJOL)

    Dr. J. T. Ekanem

    ... use of the processed seeds as food for humans and oil extracts for the manufacture of industrial products. Key words: Heat processing methods, Arachis hypogaea seeds, nutrient composition, lipid characterization. ..... the teeth, painful swellings of the joints and decreased .... (1990) Chemical composition of yam beans.

  17. Effect of alumina nanofiller on properties of heat-treated glass composite sealants.

    Science.gov (United States)

    Lee, Dong Bok; Jang, Dong-Hoon; Kim, Bong-Su; Kim, Kwang-Joong; Park, Sung; Lee, Jong-Ho; Lee, Hae-Weon; Lee, Jae Chun

    2014-11-01

    Alkali/alkaline-earth borosilicate glass-alumina composites containing 10 vol% Al2O3 were prepared for use as solid oxide fuel cell sealants. The effect of heat treatment and Al2O3, addition on the viscosities and electrical conductivities was investigated to improve cyclic sealing performance. Upon a 48-h heat treatment, the viscosity of the glass-alumina composites at 750 degrees C was approximately four orders of magnitude higher than that of the base glass owing to the crystallization of the glass in the presence of Al2O3. Heat treatment increased the electrical conductivities of both the base glass and the glass-alumina composites. The electrical conductivities of glass-alumina composites in the range from 400 degrees C to 550 degrees C were three times higher than those of the base glass regardless of heat treatment. This increase in the conductivities and viscosities by heat treatment was attributed to the devitrification and structural densification of the sealing glass and the partial dissolution of the Al2O3 filler in alkali/alkaline-earth borosilicate sealing glass.

  18. Development of glass fibre reinforced composites using microwave heating technology

    Science.gov (United States)

    Köhler, T.; Vonberg, K.; Gries, T.; Seide, G.

    2017-10-01

    Fibre reinforced composites are differentiated by the used matrix material (thermoplastic versus duroplastic matrix) and the level of impregnation. Thermoplastic matrix systems get more important due to their suitability for mass production, their good shapeability and their high impact resistance. A challenge in the processing of these materials is the reduction of the melt flow paths of the thermoplastic matrix. The viscosity of molten thermoplastic material is distinctly higher than the viscosity of duroplastic material. An approach to reduce the flow paths of the thermoplastic melt is given by a commingling process. Composites made from commingling hybrid yarns consist of thermoplastic and reinforcing fibres. Fabrics made from these hybrid yarns are heated and consolidated by the use of heat pressing to form so called organic sheets. An innovative heating system is given by microwaves. The advantage of microwave heating is the volumetric heating of the material, where the energy of the electromagnetic radiation is converted into thermal energy inside the material. In this research project microwave active hybrid yarns are produced and examined at the Institute for Textile Technology of RWTH Aachen University (ITA). The industrial research partner Fricke und Mallah Microwave Technology GmbH, Peine, Germany develops an innovative pressing systems based on a microwave heating system. By implementing the designed microwave heating technology into an existing heat pressing process, FRTCs are being manufactured from glass and nanomodified polypropylene fibre woven fabrics. In this paper the composites are investigated for their mechanical and optical properties.

  19. Improved Heat Treatment Of Steel Alloy 4340

    Science.gov (United States)

    Cooper, Lawrence B.

    1993-01-01

    New process takes significantly less time than prior heat-treatment processes. Involves placing steel plate directly in furnace and heat-treating. Plate then quenched in slowly moving oil to reduce stresses. Any deflection then pressed out. Possible uses of 4340 steel include new and improved bulletproof vests for military and police personnel and armor for bulletproof automobiles for military, police, diplomatic, and private users. Also used in other military land vehicles as tanks and in both military and civilian aircraft. Lighter armorplate enables land vehicles and aircraft to attain greater speed and maneuverability, consume less fuel, and afford better protection from snipers or terrorists.

  20. 7 CFR 305.25 - Dry heat treatment schedules.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Dry heat treatment schedules. 305.25 Section 305.25... SERVICE, DEPARTMENT OF AGRICULTURE PHYTOSANITARY TREATMENTS Heat Treatments § 305.25 Dry heat treatment schedules. Treatment schedule Temperature ( °F) Time Directions T302-a-1-2 168 minimum At least 2 hours...

  1. Shear Properties of Carbon Fiber/Phenolic Resin Composites Heat Treated at High Temperatures

    OpenAIRE

    Homero Paula Silva; Luiz Cláudio Pardini; Edison Bittencourt

    2016-01-01

    ABSTRACT Carbon fiber/phenolic resin composites have long been used as ablative materials in rocketry. Ablation is a complex multiscale problem where radiative and convective heating leads to the pyrolysis of phenolic resin matrix, resulting in the formation of a porous insulation char as thermal protection. This study investigates the shear properties evolution during the heat treatment of a carbon fiber/phenolic resin nozzle extension entrance (exit cone) which is part of an integrated nozz...

  2. Sweat composition in exercise and in heat.

    Science.gov (United States)

    Verde, T; Shephard, R J; Corey, P; Moore, R

    1982-12-01

    Sweat samples were collected from the forearms of eight male volunteers using light gauze pads applied for 20-min periods. Preliminary trials indicated that this technique yielded realistic figures for both sweat volume and sweat composition. Tests were conducted under three conditions: a) outdoor exercise, cool environment; b) indoor exercise, normal room temperatures; and c) sauna exposure. In all environments, proximal forearm samples indicated a larger sweat secretion than distal forearm or hand samples. [Mg2+] decreased as sweat flow increased, but after allowance for interindividual differences of sweat volume, [Na+], [K+], [Ca2+], and [Cl-] were independent of sweat flow rates. The differential effect of sweat flow suggests active regulation rather than contamination. Interindividual differences of sweat composition could not be explained in terms of differences in personal fitness. Sauna bathing yielded sweat with a higher [Mg2+] and [Ca2+] content than did exercise; however, [Na+], [K+], and [Cl-] were similar for the three experimental conditions. Again, the data are best explained in terms of an active regulation of sweat composition. Total ionic losses do not seem sufficient to deplete body mineral reserves unless many days of training are undertaken in a hot climate.

  3. 7 CFR 305.29 - Vacuum heat treatment schedule.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Vacuum heat treatment schedule. 305.29 Section 305.29... SERVICE, DEPARTMENT OF AGRICULTURE PHYTOSANITARY TREATMENTS Heat Treatments § 305.29 Vacuum heat treatment schedule. T111-a-1. Place bay leaves in a vacuum chamber. Starting at 0 hour, gradually reduce to 0.133 Kpa...

  4. Grain Refinement of Low Carbon Martensitic Steel by Heat Treatment

    Directory of Open Access Journals (Sweden)

    N. V. Kolebina

    2015-01-01

    Full Text Available The low-carbon steels have good corrosion and technological properties. Hot deformation is the main operation in manufacturing the parts from these steels. So one of the important properties of the material is a property of plasticity. The grain size significantly influences on the ductility properties of steel. The grain size of steel depends on the chemical composition of the crystallization process, heat treatment, and steel machining. There are plenty methods to have grain refinement. However, taking into account the large size of the blanks for the hydro turbine parts, the thermal cycling is an advanced method of the grain refinement adaptable to streamlined production. This work experimentally studies the heat treatment influence on the microstructure of the low-carbon 01X13N04 alloy steel and proposes the optimal regime of the heat treatment to provide a significantly reduced grain size. L.M. Kleiner, N.P. Melnikov and I.N. Bogachyova’s works focused both on the microstructure of these steels and on the influence of its parameters on the mechanical properties. The paper focuses mainly on defining an optimal regime of the heat treatment for grain refinement. The phase composition of steel and temperature of phase transformation were defined by the theoretical analysis. The dilatometric experiment was done to determine the precise temperature of the phase transformations. The analysis and comparison of the experimental data with theoretical data and earlier studies have shown that the initial sample has residual stress and chemical heterogeneity. The influence of the heat treatment on the grain size was studied in detail. It is found that at temperatures above 950 ° C there is a high grain growth. It is determined that the optimal number of cycles is two. The postincreasing number of cycles does not cause further reducing grain size because of the accumulative recrystallization process. Based on the results obtained, the thermal cycling

  5. Effect of heat treatment on residual stress and wear behaviors of the TiNi/Ti2Ni based laser cladding composite coatings

    Science.gov (United States)

    Tao, Yang-Feng; Li, Jun; Lv, Ying-Hao; Hu, Lie-Feng

    2017-12-01

    The TiNi/Ti2Ni based composite coatings reinforced by TiC and TiB2 were prepared on Ti6Al4V at different circumstance temperatures (25 °C, 400 °C, 600 °C, and 800 °C) by laser cladding, then were preserved for 3 h. Macromorphologies and microstructures of the coatings were examined through an optical microscope (OM), an X-ray diffractometer (XRD), a scanning electron microscope (SEM), and an energy dispersive spectrometer (EDS). Residual stresses along the depth direction of the coatings were measured by the nanoindentation method, and wear behaviors of the coatings were also investigated using an ultra-functional wear testing machine. Results showed that the coatings were mainly composed of TiNi/Ti2Ni as the matrix and TiC/TiB2 as the reinforcement. A small amount of Cr2Ti was formed in the coatings prepared at 400 °C and 600 °C. Besides that, Ti3Al was also observed in the coating prepared at 800 °C. The tensile stress existed in the coatings prepared at 25 °C, 400 °C and 600 °C when the coating prepared at 800 °C was regarded as the stress-free reference. The average residual stress in the surface of coating prepared at 25 °C reached the largest value of about 2.79 GPa and presented a decreasing tendency with increasing the circumstance temperature (1.03 GPa at 400 °C, 0.52 GPa at 600 °C, and 0 GPa at 800 °C). It revealed that the rise in circumstance temperature contributed to the reduction in cracking susceptibility in the laser cladding coating. However, the wear volumes of the coatings were increased with increasing the circumstance temperature (0.1912 mm3 at 25 °C, 0.2828 mm3 at 400 °C, 0.3732 mm3 at 600 °C, and 0.6073 mm3 at 800 °C) due to the weakening in strain-hardening effect and the reduction in reinforcement density. The wear mechanism of the coatings was transformed from the single brittle-debonding into the combination of micro-cutting and brittle-debonding when the circumstance temperature was changed from room temperature to

  6. The Design, Fabrication, and Testing of Composite Heat Exchange Coupons

    Science.gov (United States)

    Quade, Derek J.; Meador, Michael A.; Shin, Euy-Sik; Johnston, James C.; Kuczmarski, Maria A.

    2011-01-01

    Several heat exchanger (HX) test panels were designed, fabricated and tested at the NASA Glenn Research Center to explore the fabrication and performance of several designs for composite heat exchangers. The development of these light weight, high efficiency air-liquid test panels was attempted using polymer composites and carbon foam materials. The fundamental goal of this effort was to demonstrate the feasibility of the composite HX for various space exploration and thermal management applications including Orion CEV and Altair. The specific objectives of this work were to select optimum materials, designs, and to optimize fabrication procedures. After fabrication, the individual design concept prototypes were tested to determine their thermal performance and to guide the future development of full-size engineering development units (EDU). The overall test results suggested that the panel bonded with pre-cured composite laminates to KFOAM Grade L1 scored above the other designs in terms of ease of manufacture and performance.

  7. Heat Conductivity of Composite Materials with Included Balls of Zero Heat Conductivity

    Directory of Open Access Journals (Sweden)

    O. V. Pugachev

    2015-01-01

    Full Text Available The problem under consideration is to estimate the effective coefficient of heat conductivity of a material with included balls of zero heat conductivity, being either in a cubic lattice order or chaotically.The solution of heat conductivity equation can be obtained using a Wiener process. In this mathematical model, the process of heat conduction is represented by random motion of \\heat particles", although these \\particles" do not exist in a physical sense: they are special formal objects, they represent a sample of a distribution the density of which is proportional to the density of heat energy in each time moment. If one has a solid without heat exchange on its surface, the trajectories of randomly moving particles must reflect from the surface.Consider a non-bounded flat layer of a composite with its effective heat conductivity to be evaluated. As a criterion of heat conductivity, consider the probability P, which may be that a heat particle, starting from one side of the layer reaches its other side for the time less than T. For a homogeneous isotropic material, this probability is calculated analytically.Having performed a series of computing experiments simulating heat conductivity through the layer of a composite (the source of heat is applied to its surface, and on the opposite surface is heat absorbing and processed the experiments' results statistically, one obtains confidence intervals for P, wherefrom appear the confidence intervals for the effective temperature conductivity (under what temperature conductivity a homogeneous material yields the same value of P. Finally, the effective coefficient of heat conductivity is calculated by multiplying the effective coefficient of temperature conductivity with the average volume heat capacity.Various ratios of the inclusion radius to the cube lattice period (or the corresponding space densities of chaotic inclusions were considered. For series of 4,300 randomly moving particles, the

  8. Effect of heat treatment on wear resistance of a grinding plate ...

    African Journals Online (AJOL)

    The effects of heat treatment on the hardness and by extension the wear resistance of locally produced grinding plate of known composition were investigated. Specimens were prepared from the grinding plate and were heat treated at 840°C, 860°C and 880°C and quenched at different rate. Some of the specimens were ...

  9. Continuous fiber ceramic matrix composites for heat engine components

    Science.gov (United States)

    Tripp, David E.

    1988-01-01

    High strength at elevated temperatures, low density, resistance to wear, and abundance of nonstrategic raw materials make structural ceramics attractive for advanced heat engine applications. Unfortunately, ceramics have a low fracture toughness and fail catastrophically because of overload, impact, and contact stresses. Ceramic matrix composites provide the means to achieve improved fracture toughness while retaining desirable characteristics, such as high strength and low density. Materials scientists and engineers are trying to develop the ideal fibers and matrices to achieve the optimum ceramic matrix composite properties. A need exists for the development of failure models for the design of ceramic matrix composite heat engine components. Phenomenological failure models are currently the most frequently used in industry, but they are deterministic and do not adequately describe ceramic matrix composite behavior. Semi-empirical models were proposed, which relate the failure of notched composite laminates to the stress a characteristic distance away from the notch. Shear lag models describe composite failure modes at the micromechanics level. The enhanced matrix cracking stress occurs at the same applied stress level predicted by the two models of steady state cracking. Finally, statistical models take into consideration the distribution in composite failure strength. The intent is to develop these models into computer algorithms for the failure analysis of ceramic matrix composites under monotonically increasing loads. The algorithms will be included in a postprocessor to general purpose finite element programs.

  10. Influence of heat processing methods on the nutrient composition ...

    African Journals Online (AJOL)

    The effects of heat processing methods on the proximate composition, caloric value, mineral concentrations, vitamins A and C levels and lipid characterization of seed pastes of Arachis hypogaea were investigated. Moisture content was highest (25.2 ± 0.36%) in boiled seeds (BS) followed by raw seeds (RS) (4.58± 0.24%) ...

  11. Atmospheric composition affects heat- and mass-transfer processes

    Science.gov (United States)

    Blakely, R. L.; Nelson, W. G.

    1970-01-01

    For environmental control system functions sensitive to atmospheric composition, components are test-operated in helium-oxygen and nitrogen-oxygen mixtures, pure oxygen, and air. Transient heat- and mass-transfer tests are conducted for carbon dioxide adsorption on molecular sieve and for water vapor adsorption on silica gel.

  12. HIFU treatment time reduction through heating approach optimisation.

    Science.gov (United States)

    Coon, Joshua; Todd, Nick; Roemer, Robert

    2012-01-01

    This study evaluated the HIFU treatment time reductions attainable for several scan paths when optimising the heating approach used (single, discrete pulses versus volumetric scanning) and the paths' focal zone heating locations'; number (N(FZL)), spacings, sequencing order, number of heating cycles (N(CYCLES)), and heating times. Also evaluated were the effects of focal zone size, increased tissue absorptivity due to heating, and optimisation technique. Treatments of homogeneous constant property tumours were simulated for several simple generic tumour shapes and sizes. The concentrated heating approach (which delivered the desired thermal dose to each location in one discrete heating pulse (N(CYCLES) = 1)) was compared to the fractionated heating approach (which dosed the tumour using multiple, shorter pulses repeatedly scanned around the heating path (i.e. 'volumetric scanning' with N(CYCLES) > 1)). Treatment times were minimised using both simultaneous, collective pulse optimisation (which used full a priori knowledge of the interacting effects of all pulses) and sequential, single pulse optimisation (which used only the information from previous pulses and cooling of the current pulse). Optimised concentrated heating always had shorter treatment times than optimised fractionated heating, and concentrated heating resulted in less normal tissue heating. When large, rapid tissue absorptivity changes were present (doubled or quadrupled immediately after heating) the optimal ordering of the scan path's sequence of focal zone locations changed. Concentrated heating yields significant treatment time reductions and less normal tissue heating when compared to all fractionated scanning approaches, e.g. volumetric scanning.

  13. [Treatment of syphilis with malaria or heat].

    Science.gov (United States)

    Verhave, Jan Peter

    2016-01-01

    Until the end of the Second World War, syphilis was a common sexually transmitted infection. This stigmatising infectious disease caused mental decline, paralysis and eventually death. The history of syphilis was given public attention because of 'malaria therapy', which had been applied from the First World War onwards in patients with paralytic dementia. In 1917, the Austrian physician Julius Wagner-Jauregg (1857-1940) induced fever in these patients by infecting them with malaria parasites; in 1927, he received the Nobel Prize for his discovery of the healing properties of malarial fever. One source, not cited anywhere, is an interview that the American bacteriologist and science writer/medical journalist Paul de Kruif conducted with Wagner-Jauregg in 1930. The reporting of this meeting, and De Kruif's later involvement in the mechanical heat treatment of patients with syphilis, form the inspiration for this article. When penicillin became available, both treatments became obsolete.

  14. Efficacy of heat treatment for disinfestation of concrete grain silos

    Science.gov (United States)

    Field experiments were conducted in 2007 and 2008 to evaluate heat treatment for disinfestations of empty concrete elevator silos. A Mobile Heat Treatment Unit was used to introduce heat into silos to attain target conditions of 50°C for at least 6 h. Ventilated plastic containers with a capacity of...

  15. Changes occurring in vegetable oils composition due to microwave heating

    Directory of Open Access Journals (Sweden)

    Hassan El-Mallah, M.

    2003-12-01

    Full Text Available The effect of microwave heating on three vegetable oils having different lipid compositions was studied. Sunflower, soybean and peanut oils in comparison with oil admixture of soybean and peanut oil (1:1, w/w, were selected for this study. Each oil was heated for 2, 4, 6, 8, 10, 12, 15 and 18 minutes in microwave oven. Peroxide value, free acidity and colour absorbance (at 420 nm were proportionally increasing with the increase of heating period. Colour absorption threw light on the formation of browning products arising from phospholipids during microwave heating. Total tocopherol contents were determined by preparative thin layer chromatography, whereas the fatty acid compositions and formed epoxy acid were analyzed by capillary gas liquid chromatography. The formed conjugated dienes and trienes were determined by UV spectrophotometry. It was found that the total tocopherols of the microwave heated oils, decreased depending on the type of the predominating tocopherols. Also a relation of peroxide formation, during microwave heating, with changes in total tocopherol composition was discussed. It was found that polyunsaturated fatty acids generally decreased by increasing the heating period. The results obtained from the heated oil admixture helped interpret the results obtained from other heated individual oils.Se estudia el efecto del calentamiento en horno de microondas sobre aceites de diferente composición en ácidos grasos. Aceites de girasol, soja, cacahuete y una mezcla de soja y cacahuete al 50%, se calentaron durante 2, 4, 6, 8 10, 12, 15 y 18 minutos. Los valores de índice de peróxidos, acidez libre y absorbancia a 420 nm fueron proporcionales al tiempo de calentamiento. Otras determinaciones incluyeron el contenido total en tocoferoles mediante cromatografía en capa fina, la composición en ácidos grasos y en epoxiácidos mediante cromatografía gas líquido, y la formación de dienos y trienos conjugados mediante

  16. Organic/Inorganic Polymeric Composites for Heat-Transfer Reduction

    Science.gov (United States)

    Smith, Trent; Williams, Martha

    2008-01-01

    Organic/inorganic polymeric composite materials have been invented with significant reduction in heat-transfer properties. Measured decreases of 20-50 percent in thermal conductivity versus that of the unmodified polymer matrix have been attained. These novel composite materials also maintain mechanical properties of the unmodified polymer matrix. The present embodiments are applicable, but not limited to: racing applications, aerospace applications, textile industry, electronic applications, military hardware improvements, and even food service industries. One specific application of the polymeric composition is for use in tanks, pipes, valves, structural supports, and components for hot or cold fluid process systems where heat flow through materials is problematic and not desired. With respect to thermal conductivity and physical properties, these materials are superior alternatives to prior composite materials. These materials may prove useful as substitutes for metals in some cryogenic applications. A material of this type can be made from a blend of thermoplastics, elastomers, and appropriate additives and processed on normal polymer processing equipment. The resulting processed organic/inorganic composite can be made into fibers, molded, or otherwise processed into useable articles.

  17. Induction heat treatment of laser welds

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove; Sørensen, Joakim Ilsing

    2003-01-01

    750º to 450º C. Initially, a simple analytical model was used to calculate the ideal energy contributions from a CO2 high power laser source together with an induction heat source such that the temperature can be kept at 600º C for 2.5 seconds. This knowledge was then used for the design......In this paper, a new approach based on induction heat-treatment of flat laser welded sheets is presented. With this new concept, the ductility of high strength steels GA260 with a thickness of 1.8 mm and CMn with a thickness of 2.13 mm is believed to be improved by prolonging the cooling time from...... of an induction coil. A number of systematic laboratory tests were then performed in order to study the effects of the coil on bead-on-plate laser welded samples. In these tests, important parameters such as coil current and distance between coil and sample were varied. Temperature measurements were made...

  18. Cast construction elements for heat treatment furnaces

    Directory of Open Access Journals (Sweden)

    B. Piekarski

    2011-07-01

    Full Text Available The study presents sketches and photos of the cast creep-resistant components used in various types of heat treatment furnaces. The shape of the elements results from the type of the operation carried out in the furnace, while dimensions are adjusted to the size of the furnace working chamber. The castings are mainly made from the high-alloyed, austenitic chromium-nickel or nickel-chromium steel, selecting the grade in accordance with the furnace operating conditions described by the rated temperature, the type and parameters of the applied operating atmosphere, and the charge weight. Typical examples in this family of construction elements are: crucibles, roller tracks, radiant tubes and guides. The majority of castings are produced in sand moulds.

  19. Hydrolysis and heat treatment of aluminum dust.

    Science.gov (United States)

    López, F A; Peña, M C; López-Delgado, A

    2001-06-01

    Aluminum dust is a toxic and hazardous byproduct of Al remelting. The present research was performed to characterize and evaluate its behavior in water. The materials obtained by hydrolysis were also characterized, and the gases generated during the process were qualitatively analyzed. The effects of hydrolysis reaction time and temperature on the dust were also explored. The hydrolysis of Al dust is an exothermic reaction that gave rise to a solid composed of aluminum oxide, silicon oxide, and spinel (MgAl2O4). Most of the CH4, NH3, and SH2 gases generated were emitted immediately upon the start of the reaction, though their production continued for a long time. This slow reaction, which was moderately accelerated by temperature, led to the formation of a material less reactive than the untreated dust. On the other hand, heat treatment of the dust gave rise to an inert material composed of spinel, alumina, and magnesium and aluminum silicates.

  20. Preparation of fine powdered composite for latent heat storage

    Energy Technology Data Exchange (ETDEWEB)

    Fořt, Jan, E-mail: jan.fort.1@fsv.cvut.cz; Trník, Anton, E-mail: anton.trnik@fsv.cvut.cz; Pavlíková, Milena, E-mail: milena.pavlikova@fsv.cvut.cz; Pavlík, Zbyšek, E-mail: pavlikz@fsv.cvut.cz [Department of Materials Engineering and Chemistry, Faculty of Civil Engineering, Czech Technical University in Prague, Thákurova 7, 166 29 Prague (Czech Republic); Pomaleski, Marina, E-mail: marina-pomaleski@fsv.cvut.cz [Faculty of Civil Engineering, Architecture and Urbanism, University of Campinas, R. Saturnino de Brito 224, 13083-889 Campinas – SP (Brazil)

    2016-07-07

    Application of latent heat storage building envelope systems using phase-change materials represents an attractive method of storing thermal energy and has the advantages of high-energy storage density and the isothermal nature of the storage process. This study deals with a preparation of a new type of powdered phase change composite material for thermal energy storage. The idea of a composite is based upon the impregnation of a natural silicate material by a reasonably priced commercially produced pure phase change material and forming the homogenous composite powdered structure. For the preparation of the composite, vacuum impregnation method is used. The particle size distribution accessed by the laser diffraction apparatus proves that incorporation of the organic phase change material into the structure of inorganic siliceous pozzolana does not lead to the clustering of the particles. The compatibility of the prepared composite is characterized by the Fourier transformation infrared analysis (FTIR). Performed DSC analysis shows potential of the developed composite for thermal energy storage that can be easily incorporated into the cement-based matrix of building materials. Based on the obtained results, application of the developed phase change composite can be considered with a great promise.

  1. The causes of milk deposit formation on the walls of the heat exchangers during the heat treatment of milk

    Directory of Open Access Journals (Sweden)

    Bojan Matijević

    2006-03-01

    Full Text Available The results of research on finding the causes and preventing the formation of milk deposit are described in this paper.During the heat treatment of milk, an unwanted phenomenon occurs; the formation of milk deposit on heating surfaces of heat exchangers. This phenomenon causes the decrease of heat transfer coefficient as well as the pressure drop, it restricts the flow of milk, and causes additional production costs and increases production loss.The formation of milk deposit is a result of complex processes caused by thermal treatment of proteins and mineral substances in milk. Factors which cause milk deposit are: pH - value, the amount of proteins and mineral substances in milk, dissolved gases in milk, characteristics of heating surface, the difference in temperatures of milk and heating surfaces, and the regime of milk circulation. The chemical composition of milk can not be influenced, but the standards of heat treatment in order to minimise this phenomenon can, and that is precisely the topic of the latest researches.

  2. Effects of heat treatment on the mechanical properties of kenaf fiber

    Energy Technology Data Exchange (ETDEWEB)

    Carada, Paulo Teodoro D. L. [Master’s student in the Graduate School of Science and Engineering, Mechanical Engineering, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe City, Kyoto Prefecture, 610-0394 (Japan); Fujii, Toru; Okubo, Kazuya [Professor in the Faculty of Science and Engineering, Department of Mechanical and Systems Engineering, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe City, Kyoto Prefecture, 610-0394 (Japan)

    2016-05-18

    Natural fibers are utilized in various ways. One specific application of it, is in the field natural fiber composite (NFC). Considerable amount of researches are conducted in this field due to rising concerns in the harmful effects of synthetic materials to the environment. Additionally, these researches are done in order to overcome the drawbacks which limit the wide use of natural fiber. A way to improve NFC is to look into the reinforcing component (natural fiber). Treatments, which are classified as mechanical or chemical in nature, can be done in order to improve the performance of the natural fiber. The aim of this study is to assess the effects of heat treatment in the mechanical properties of kenaf fiber. In addition, the response of mechanical properties after exposure to high moisture environment of heat-treated kenaf fibers was observed. Heat treatment was done for one hour with the following heating temperatures: 140, 160, 180, and 200 °C. X-ray diffraction analysis was done to calculate the crystallinity index of kenaf fibers after heat treatment. The results showed that increase in tensile strength can be attained when kenaf fibers are heat treated at 140 °C. However, the tensile modulus showed inconsistency with respect to heat treatment temperature. The computed crystallinity index of the fiber matched the tensile strength observed in non-treated and heat-treated kenaf fibers. The results obtained in this study can be used for applications where heat treatment on kenaf fibers is needed.

  3. Influence of the chemical composition, heat and surface treatment in the biofouling of austenitic stainless steels; Influencia de la composicion quimica, del tratamiento termico y del acabado supreficial en el bioensuciamiento de aceros inoxidables austeniticos

    Energy Technology Data Exchange (ETDEWEB)

    Sarro, M. I.; Aleman, O.; Moreno, D. A.; Roso, M.; Ranninger, C.

    2004-07-01

    The main objective of this study was to analyse the biofouling processes in the kinds of stainless steels used normally in industry (UNS S30400, UNS S30403 and UNS S31600), with different surface treatments after grinding and polishing. The study was developed using two microscopy techniques. Scanning Electron Microscopy (SEM) was used to evaluate the microorganisms distribution in the materials, and Epi fluorescence Microscopy was used to evaluate the viability of cells in the biofilm. The results revealed the influence of the material, heat treatment, surface treatment and roughness in the biofouling processes in the stainless steel assays. (Author) 33 refs.

  4. High-Density Polyethylene and Heat-Treated Bamboo Fiber Composites: Nonisothermal Crystallization Properties

    Directory of Open Access Journals (Sweden)

    Yanjun Li

    2015-01-01

    Full Text Available The effect of heat-treated bamboo fibers (BFs on nonisothermal crystallization of high-density polyethylene (HDPE was investigated using differential scanning calorimetry under nitrogen. The Avrami-Jeziorny model was used to fit the measured crystallization data of the HDPE/BF composites and to obtain the model parameters for the crystallization process. The heat flow curves of neat HDPE and HDPE/heat-treated BF composites showed similar trends. Their crystallization mostly occurred within a temperature range between 379 K and 399 K, where HDPE turned from the liquid phase into the crystalline phase. Values of the Avrami exponent (n were in the range of 2.8~3.38. Lamellae of neat HDPE and their composites grew in a three-dimensional manner, which increased with increased heat-treatment temperature and could be attributed to the improved ability of heterogeneous nucleation and crystallization completeness. The values of the modified kinetic rate constant (KJ first increased and then decreased with increased cooling rate because the supercooling was improved by the increased number of nucleating sites. Heat-treated BF and/or a coupling agent could act as a nucleator for the crystallization of HDPE.

  5. Variation of protein corona composition of gold nanoparticles following plasmonic heating.

    Science.gov (United States)

    Mahmoudi, Morteza; Lohse, Samuel E; Murphy, Catherine J; Fathizadeh, Arman; Montazeri, Abbas; Suslick, Kenneth S

    2014-01-08

    It is well recognized that the primary interaction of most biological environments with nanoparticles (NPs) is strongly influenced by a long-lived ("hard") protein corona that surrounds the NP and remains strongly adsorbed to its surface. The amount and composition of associated proteins in the corona adsorbed onto the NPs is related to several important factors, including the physicochemical properties of the NPs and the composition of the protein solution. Here, for the first time, it is shown that plasmonic heat induction (by laser activation) leads to significant changes in the composition of the hard protein corona adsorbed on low aspect ratio gold nanorods. Using mass spectrometry, several proteins in the corona were identified whose concentrations change most substantially as a result of photoinduced (plasmonic) heating versus simple thermal heating. Molecular modeling suggests that the origin of these changes in protein adsorption may be the result of protein conformational changes in response to much higher local temperatures that occur near the gold nanorods during photoinduced, plasmonic heating. These results may define new applications in vivo for NPs with hyperthermia capability and better define the likely interactions of cells with NPs after plasmonic heating. Potential changes in the protein corona following hyperthermia treatment may influence the final biological fate of plasmonic NPs in clinical applications and help elucidate safety considerations for hyperthermia applications.

  6. Foamable compositions and formations treatment

    Energy Technology Data Exchange (ETDEWEB)

    Clampitt, R.L.

    1981-11-17

    Thermally stable foamable gelled compositions are disclosed suitable for postprimary oil recovery e.g., steam- or gas-foamed systems comprising water, a surfactant, a polymeric viscosifier, an aldehyde component, and at least one phenolic component such as resorcinol, catechol, and the like, as well as selected oxidized phenolic materials such as 1,4-benzoquinone of natural or synthetic origin and natural and modified tannins. The gel compositions can additionally contain gel stabilizers such as sulfomethylated quebracho (Smq) and chemical buffering agents such as sodium bicarbonate.

  7. Process map for laser heat treatment of carbon steels

    Science.gov (United States)

    Ki, Hyungson; So, Sangwoo

    2012-10-01

    We propose a process map for diode-laser heat treatment of carbon steels. After first identifying a heat treatable region in terms of laser intensity and interaction time using a heat conduction model, two most important factors in heat treatment, carbon diffusion time in austenite and cooling time, are calculated and plotted in the heat treatable region. Because overall characteristics of laser heat treatment for a given steel type can be graphically visualized on a map, this map can be used in the determination of optimal process parameters. Hardening depth is also calculated using the concept of the critical effective carbon diffusion time. For demonstration and validation purposes, we have systematically conducted laser heat treatment on AISI 1020 and 1035 steel specimens using a 3 kW diode laser and measured surface hardness and hardening depth. The experimental results are in agreement with the calculated process map.

  8. Enhancing composite durability : using thermal treatments

    Science.gov (United States)

    Jerrold E. Winandy; W. Ramsay Smith

    2007-01-01

    The use of thermal treatments to enhance the moisture resistance and aboveground durability of solid wood materials has been studied for years. Much work was done at the Forest Products Laboratory in the last 15 years on the fundamental process of both short-and long-term exposure to heat on wood materials and its interaction with various treatment chemicals. This work...

  9. Effects of heat treatment of wood on hydroxylapatite type mineral precipitation and biomechanical properties in vitro.

    Science.gov (United States)

    Rekola, J; Lassila, L V J; Hirvonen, J; Lahdenperä, M; Grenman, R; Aho, A J; Vallittu, P K

    2010-08-01

    Wood is a natural fiber reinforced composite. It structurally resembles bone tissue to some extent. Specially heat-treated birch wood has been used as a model material for further development of synthetic fiber reinforced composites (FRC) for medical and dental use. In previous studies it has been shown, that heat treatment has a positive effect on the osteoconductivity of an implanted wood. In this study the effects of two different heat treatment temperatures (140 and 200 degrees C) on wood were studied in vitro. Untreated wood was used as a control material. Heat treatment induced biomechanical changes were studied with flexural and compressive tests on dry birch wood as well as on wood after 63 days of simulated body fluid (SBF) immersion. Dimensional changes, SBF sorption and hydroxylapatite type mineral formation were also assessed. The results showed that SBF immersion decreases the biomechanical performance of wood and that the heat treatment diminishes the effect of SBF immersion on biomechanical properties. With scanning electron microscopy and energy dispersive X-ray analysis it was shown that hydroxylapatite type mineral precipitation formed on the 200 degrees C heat-treated wood. An increased weight gain of the same material during SBF immersion supported this finding. The results of this study give more detailed insight of the biologically relevant changes that heat treatment induces in wood material. Furthermore the findings in this study are in line with previous in vivo studies.

  10. Cryogenic heat treatment — a review of the current state

    Directory of Open Access Journals (Sweden)

    Kamran Amini

    2017-03-01

    Full Text Available The deep cryogenic heat treatment is an old and effective heat treatment, performed on steels and cast irons to improve the wear resistance and hardness. This process includes cooling down to the liquid nitrogen temperature, holding the samples at that temperature and heating at the room temperature. The benefits of this process are significant on the ferrous materials, but recently some studies focused on other nonferrous materials. This study attempts to clarify the different behavior of some materials subjected to the deep cryogenic heat treatment, as well as explaining the common theories about the effect of the cryogenic heat treatment on these materials. Results showed that polymers exhibit different behavior regarding to their crystallinity, however the magnesium alloys, titanium alloys and tungsten carbide show a noticeable improvement after the deep cryogenic heat treatment due to their crystal structure.

  11. Coupled heating/forming optimization of knitted reinforced composites

    Science.gov (United States)

    Pancrace, Johann

    The feasibility of knitted fabric reinforcement for highly flexible composites has been investigated for the thermoforming process. The composite sheets were made through compression molding before being shaped. We used thermoplastic elastomers as matrices: Thermoplastic Elastomers and Thermoplastic Olefins. The knit reinforcement was provided by jersey knitted fabrics of polyester fibers. We first introduced the fundamentals involved in the study. The manufacturing is presented through compression molding and thermoforming. The latter is a two-step process: IR heating and plug/pressure assisted deformations. For the IR heating phase, several material properties have been characterized: the emissivity of matrices, absorption, reflection and transmission of radiations in the composite structure have been studied. We particularly paid attention to the reflection on the composite surfaces. The non-reflected or useful radiations leading to the heating are quantified and simulated for three emitter-composite configurations. It has been found that the emitter temperatures and the angle of incidence have significant roles in the IR heating phase. Thermal properties such as calorific capacity and thermal conductivity of the composites were also presented. Thermograms were carried out with an IR camera. Equipment and Thermogram acquisitions were both presented. Optimization of emitters was performed for a three emitter system. The objective function method has been illustrated. Regarding mechanical purposes, the characterizations of the matrices, reinforcements and flexible composites have been carried out. The studied loadings were uniaxial traction, pure shear and biaxial inflation. For the uniaxial extension, both the reinforcement and the composite were found highly anisotropic regarding the orientation of the loading toward the coursewise of the fabric. The resulting strains and stresses to rupture are also found anisotropic. However, for pure shear loading we observed

  12. Shear Properties of Carbon Fiber/Phenolic Resin Composites Heat Treated at High Temperatures

    Directory of Open Access Journals (Sweden)

    Homero Paula Silva

    2016-07-01

    Full Text Available Carbon fiber/phenolic resin composites have long been used as ablative materials in rocketry. Ablation is a complex multiscale problem where radiative and convective heating leads to the pyrolysis of phenolic resin matrix, resulting in the formation of a porous insulation char as thermal protection. This study investigates the shear properties evolution during the heat treatment of a carbon fiber/phenolic resin nozzle extension entrance (exit cone which is part of an integrated nozzle of launching and sounding vehicles, developed at the Instituto de Aeronáutica e Espaço (SP, Brazil. Specimens of the material (carbon fiber/phenolic resin composite were subjected to heat treatment at 500, 1,000, 1,500 and 2,000°C, and measurements of shear strength and shear modulus were performed using the Iosipescu mode. Experimental data were compared with the results obtained theoretically. Also, morphological analysis was accomplished by optical microscopy and the observation of fractured surfaces, by scanning electron microscopy. Significant morphological changes in the microstructure after heat treatments were observed. The lowest value for shear strength obtained experimentally was 4.05 MPa, which is greater than the ultimate value obtained analytically (2.35 MPa, fulfilling its structural function during the propulsion time.

  13. Prediction of heat treatment in food processing machinery

    DEFF Research Database (Denmark)

    Karlson, Torben; Friis, Alan; Szabo, Peter

    1997-01-01

    The velocity and temperature fields of a shear thinning fluid in a co-rotating disc scraped surface heat exchanger (CDHE) are calculated using the finite element method. By tracking and timingparticles through the heat exchanger residence time and thermal time distributions are computed....... The residence time distributions are compared to experimentally obtained distributions. A prediction of the heat treatment of the fluid passing through several heat exchangers inseries is obtained using the thermal time distributions....

  14. Influence of different heat treatment programs on properties of sol ...

    Indian Academy of Sciences (India)

    DTA) experiments, five heat treatment programs were developed. All programs lead to single phase perovskite KNN films with random crystal orientation, but only the programs that included a treatment after each single spin-coating step ...

  15. Self-healing epoxy composite with heat-resistant healant.

    Science.gov (United States)

    Yuan, Yan Chao; Ye, Xiao Ji; Rong, Min Zhi; Zhang, Ming Qiu; Yang, Gui Cheng; Zhao, Jian Qing

    2011-11-01

    To provide self-healing epoxy composite with adequate heat resistance for high-performance application, we developed a novel microencapsulated epoxy/mercaptan healing agent. The key measure lies in usage of diglycidyl ether of bisphenol A (EPON 828) as the polymerizable component and 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30) as the catalyst. Because of the higher thermal stability of EPON 828 and lower volatility of DMP-30, the healing agent and the self-healing composite not only survive high-temperature curing and thermal exposure, but also offer satisfactory capability of autonomous properties restoration, as characterized by both fracture mechanics and fatigue tests. Especially when the operation temperature is not higher than 200 °C, the performance of the healing system is nearly independent of thermal history.

  16. Effect of heat treatment on structure and magnetic properties of ...

    Indian Academy of Sciences (India)

    Fe46Co35Ni19/CNTs nanocomposites have been prepared by an easy two-step route including adsorption and heat treatment processes. We investigated the effect of heat treatment conditions on structure, morphology, nanoparticle sizes and magnetic properties of the Fe46Co35Ni19 alloy nanoparticles attached on the ...

  17. Effect of heat treatment temperature on microstructure and ...

    Indian Academy of Sciences (India)

    Effect of heat treatment temperature on microstructure and electrochemical properties of hollow carbon spheres prepared in high-pressure argon. Boyang Liu Yun ... 40 cycles. However, the discharge capacity of the HCSs decreases and the cycling performance is improved with the increase of heat treatment temperature.

  18. IMPROVED MANUFACTURING CANNED "COMPOTE CHERRY" USING COMBINED HEAT TREATMENT

    Directory of Open Access Journals (Sweden)

    A. F. Demirova

    2013-01-01

    Full Text Available The results of studies on the development of new modes of heat sterilization compote cherry using stepwise heating in a stream of hot air and hot water dushevaniem air cooled rotating container. Revealed that the modes provide commercial sterility of finished products, reducing the length of the heat treatment and the quality of the finished product. Are some of the modes of heat sterilization step of cherry compote in a stream of heated air and water dushevaniem air-cooled rotating container.

  19. Effect of heat treatment and packaging systems on the stability of fish sausage

    OpenAIRE

    Bruna Rafaela Dallabona; Laura Beatriz Karam; Roberta Wagner; Dayse Aline Ferreira Silva Bartolomeu; Jorge Daniel Mikos; João Gabriel Phabiano Francisco; Renata Ernlund Freitas Macedo; Peter Gaberz Kirschnik

    2013-01-01

    The purpose of this study was to evaluate the physicochemical and microbiological stability of sausages produced from mechanically separated fish meat (MSM) obtained from Nile tilapia filleting residues. Different heat treatments (pasteurization or smoking) and packaging systems (conventional or vacuum) were used. The sausages were characterized for chemical composition, weight loss, water activity, instrumental texture and sensorial analysis. Additionally, microbiological analysis, instrumen...

  20. Effect of Dry Heat Pre-Treatment (Toasting) on the Cooking Time of ...

    African Journals Online (AJOL)

    Four cowpea varieties (Brown beans, Oloka beans, IAR48 and IT89KD-288) were toasted at 105oC, and used to study the effect of dry heat treatment on the cooking time and nutrient composition of cowpea seeds and also its effect on the functional properties of resultant flour of the cowpea seed varieties. Toasting reduced ...

  1. Formosan subterranean termite resistance to heat treatment of Scots pine and Norway spruce

    Science.gov (United States)

    W. Ramsay Smith; Andreas O. Rapp; Christian Welzbacher; Jerrold E. Winandy

    2003-01-01

    New challenges to the durability of wood building materials have arisen in the U.S. The Formosan subterranean termite (Coptotermes formosanus Shiraki) now infests sizable portions of the U.S. south (Figure 1) and their range is extending. Heat treatments offer a unique opportunity for wood-based composites because many of the process techniques already employ various...

  2. Study Of Gear Teeth Distortions Due To Heat Treatment

    Directory of Open Access Journals (Sweden)

    V. Khade

    2015-02-01

    Full Text Available Abstract The work aims to study the distortion occurred due to heat treatment on the Gear teeth. The paper studies various causes of distortion control techniques to eliminate distortion which includes changes in design selection of material heat treatment process mainly due to quenching that includes cooling rates quenching mediums fixtures. An experimental study and results conducted for the effects of the distortion on the Gear teeth and to reduce the distortion with certain changes design modification resulting in shape amp size changes phase changes changes in hardness microstructure and residual stresses. It is observed that adequate velocity of quench oil around the component to be heat treated ensures uniform amp desired cooling rate as per heat treatment cycle. Modification in design of baffles achieved the adequate velocity and minimization of distortion. Also Fixtures for holding finished parts or assemblies during heat treatment may be either support or restraint type to control dimensional relations during aging.

  3. Effects of Heat Stress on Metabolite Accumulation and Composition, and Nutritional Properties of Durum Wheat Grain.

    Science.gov (United States)

    de Leonardis, Anna Maria; Fragasso, Mariagiovanna; Beleggia, Romina; Ficco, Donatella Bianca Maria; de Vita, Pasquale; Mastrangelo, Anna Maria

    2015-12-19

    Durum wheat (Triticum turgidum (L.) subsp. turgidum (L.) convar. durum (Desf.)) is momentous for human nutrition, and environmental stresses can strongly limit the expression of yield potential and affect the qualitative characteristics of the grain. The aim of this study was to determine how heat stress (five days at 37 °C) applied five days after flowering affects the nutritional composition, antioxidant capacity and metabolic profile of the grain of two durum wheat genotypes: "Primadur", an elite cultivar with high yellow index, and "T1303", an anthocyanin-rich purple cultivar. Qualitative traits and metabolite evaluation (by gas chromatography linked to mass spectrometry) were carried out on immature (14 days after flowering) and mature seeds. The effects of heat stress were genotype-dependent. Although some metabolites (e.g., sucrose, glycerol) increased in response to heat stress in both genotypes, clear differences were observed. Following the heat stress, there was a general increase in most of the analyzed metabolites in "Primadur", with a general decrease in "T1303". Heat shock applied early during seed development produced changes that were observed in immature seeds and also long-term effects that changed the qualitative and quantitative parameters of the mature grain. Therefore, short heat-stress treatments can affect the nutritional value of grain of different genotypes of durum wheat in different ways.

  4. Influence of different heat treatment programs on properties of sol ...

    Indian Academy of Sciences (India)

    C, respectively. In the three-step program, T1, the sample was first dried, then pyrolyzed, and finally calcinated, in the two-step pro- gram, T2, the drying step was omitted, while in program. T3 (one step), the sample was directly heated to the calcina- tion temperature. Heat treatment programs T4 and T5 were similar to heat ...

  5. Effect of heat treatment on viability of Taenia hydatigena eggs.

    Science.gov (United States)

    Buttar, Birpal S; Nelson, Mark L; Busboom, Jan R; Hancock, Dale D; Walsh, Douglas B; Jasmer, Douglas P

    2013-04-01

    Effects of heat treatments on activation and infectivity of Taenia hydatigena eggs were assessed. Eggs containing oncospheres were used for in vitro and in vivo studies to determine the response to 5min of heat treatment, ranging from room temperature (22°C) to 60°C. The study demonstrated 99.47% and 100% reduction in oncosphere activation or infectivity after 5min of heat treatment at 60°C and 57.38°C under in vitro and in vivo conditions, respectively. Similar results between the two approaches indicted the appropriateness of the in vitro methods to identify oncosphericidal treatments of practical significance. Similar heat treatments may also be effective against Taenia saginata and help to reduce occurrence of beef cysticercosis. Published by Elsevier Inc.

  6. Effect of Heat Treatment on Properties of Glass Nanocomposite Sealants.

    Science.gov (United States)

    Lee, Dong Bok; Ha, Su-Jeong; Jang, Dong-Hoon; Park, Sung; Bae, Joongmyeon; Lee, Jae Chun

    2015-01-01

    The objective of this study was to investigate the effect of heat treatments on the viscosities and electrical conductivities of glass sealants to be used in solid oxide fuel cells. Glass-based sealants, both with and without an alumina nanopowder added as a nanofiller, were heat treated at temperatures ranging from 750 degrees C to 770 degrees C for periods of up to 240 h. The effects of heat treatments on the viscosities, electrical conductivities and phase transformations of the sealants were investigated. The results showed that alumina nanopowder added to the glass increased both high-temperature electrical conductivities and the viscosities of the sintered glass nanocomposite sealants. However, lengthy heat treatments decreased the electrical conductivities of the glass nanocomposite sealants. This decrease in the conductivities of the heat-treated glass nanocomposites was attributed to the crystallization of glass phase, owing to the dissolution of the alumina nanofiller in the sealing glass.

  7. EFFECT OF POST-WELD HEAT TREATMENT ON THE ...

    African Journals Online (AJOL)

    Effect of post- weld heat treatment on the microstructure and mechanical properties of arc welded medium carbon steel was investigated. Medium carbon steel samples were butt- welded by using the shielded metal arc welding technique and, thereafter, heat treated by annealing, normalising and quench hardening in ...

  8. The effects of heat treatment on physical and technological ...

    African Journals Online (AJOL)

    obtained from Alapli-Zonguldak Forest Enterprises, Turkey, were subjected to heat treatment at varying temperatures and for varying durations. The physical properties of heat-treated and control samples were tested, and oven-dry density, air-dry density, and swelling properties were determined. The mechanical properties ...

  9. (AJST) EFFECT OF HEAT TREATMENT ON WEAR RESISTANCE ...

    African Journals Online (AJOL)

    ABSTRACT: The effects of heat treatment on the hardness and by extension the wear resistance of locally produced grinding plate ... from the grinding plate and were heat treated at 840°C, 860°C and 880°C and quenched at different rate. Some of the ... during dry sliding at low loading conditions has been attributed to the ...

  10. Influence of heat treatment on microstructure and passivity of Cu ...

    Indian Academy of Sciences (India)

    The corrosion resistance in buffer solution (pH 9), H3BO3/Na2B4O7·10H2O, with various concentrations of chloride ions was evaluated by potentiodynamic polarization curves and compared with multi- component Pourbaix diagrams. A correlation between the heat treatment, microstructure and passivity of the heat.

  11. Heat Treatment and Properties of Iron and Steel

    National Research Council Canada - National Science Library

    Digges, Thomas

    1966-01-01

    This monograph is a revision of the previous NBS Monograph 18. Its purpose is to provide an understanding of the heat treatment of iron and steels, principally to those unacquainted with this subject...

  12. Effect of Heat Treatment on Microstructural Changes in Aluminium Bronze

    Directory of Open Access Journals (Sweden)

    Hájek J.

    2016-09-01

    Full Text Available This paper attempts to summarise the microstructural changes which take place in aluminium bronzes during heat treatment. Another objective of this study was to map the potential of a certain type of aluminium bronzes for undergoing martensitic transformation. The methods, which were chosen for assessing the results of heat treatment with regard to their availability, included measurement of hardness and observation of microstructure using light and scanning electron microscopy, Additional tools for evaluation of microstructure comprised measurement of microhardness and chemical analysis by EDS. An important part of the experiment is observation of microstructural changes in the Jominy bar during the end-quench test. Upon completing experiments of this kind, one can define the heat treatment conditions necessary for obtaining optimum properties. In addition, the paper presents important findings on how to improve the corrosion resistance of aluminium bronzes by special heat treatment sequences.

  13. Review on prevention and treatment of severe heat stroke

    Directory of Open Access Journals (Sweden)

    Lei SU

    2011-09-01

    Full Text Available The conventional definition and typing of severe heat stroke are frequently based on its external behavior,not on its pathogenesis and essential characteristics.The present paper introduced the recognition of the essence of severe heat stroke,"the first critical point" and "the second critical point" hypotheses,as well as the academic progresses achieved domestically and abroad.The pathogenesis,clinical prevention,and treatments of heat stroke were discussed and reviewed to combine the basic research and clinical application of severe heat stroke pathogenesis,and to establish a new diagnostic criterion and therapy standard.

  14. Examination of heat treatments at preservation of grape must

    Directory of Open Access Journals (Sweden)

    Péter Korzenszky

    2014-02-01

    Full Text Available Heat treatment is a well-known process in food preservation. It is made to avoid and to slow down food deterioration. The process was developed by Louise Pasteur French scientist to avoid late among others wine further fermentation. The different heat treatments influence the shelf life in food production. In our article we present the process of grape must fermentation, as grape must is the base material of wine production. The treatment of harvested fresh grape juice has a big influence on end product quality. It is our experiments we examined the same grape must with four different methods in closed and in open spaces to determine CO2 concentration change. There are four different methods for treatment of grape juice: boiling, microwave treatment, treatment by water bath thermostat and a control without treatment. As a result of the comparison it can be stated that the heat treatment delays the start of fermentation, thereby increasing shelf life of grape must. However, no significant differences were found between two fermentation of heat-treated grape must by the microwave and water-bath thermostat. The different heat treatment of grape must base materials was done at the laboratory in Faculty of Mechanical Engineering of Szent István University. The origin of the table grapes used for the examination was Gödöllő-hillside. Normal 0 21 false false false HU X-NONE X-NONE

  15. Influence of Heat Treatments on Carotenoid Content of Cherry Tomatoes

    OpenAIRE

    D?Evoli, Laura; Lombardi-Boccia, Ginevra; Lucarini, Massimo

    2013-01-01

    Tomatoes and tomato products are rich sources of carotenoids—principally lycopene, followed by β-carotene and lutein. The aim of this work was to study the effect of heat treatment on carotenoid content in cherry tomatoes. Raw and canned products were sampled and analysed; furthermore whole, skin and pulp fractions of cherry tomatoes were analysed when raw and home-processed, in order to better understand heat treatment effects. Lycopene content in canned tomatoes was two-fold higher than in ...

  16. Transient analysis of heat and mass transfer during heat treatment of wood including pressure equation

    Directory of Open Access Journals (Sweden)

    Younsi Ramdane

    2015-01-01

    Full Text Available In the present paper, three-dimensional equations for coupled heat and mass conservation equations for wood are solved to study the transient heat and mass transfer during high thermal treatment of wood. The model is based on Luikov’s approach, including pressure. The model equations are solved numerically by the commercial package FEMLfor the temperature and moisture content histories under different treatment conditions. The simulation of the proposed conjugate problem allows the assessment of the effect of the heat and mass transfer within wood. A parametric study was also carried out to determine the effects of several parameters such as initial moisture content and the sample thickness on the temperature, pressure and moisture content distributions within the samples during heat treatment.

  17. Optical fiber temperature sensors: applications in heat treatments for foods

    Science.gov (United States)

    Sosa-Morales, María Elena; Rojas-Laguna, Roberto; López-Malo, Aurelio

    2010-10-01

    Heat treatments are important methods to provide safe foods. Conventional heat treatments involve the application of steam and recently microwave treatments have been studied and applied as they are considered as fast, clean and efficient. Optical fiber sensing is an excellent tool to measure the temperature during microwave treatments. This paper shows the application of optical fiber temperature sensing during the heat treatment of different foods such as vegetables (jalapeño pepper and cilantro), cheese and ostrich meat. Reaching the target temperature, important bacteria were inactivated: Salmonella, Listeria and Escherichia coli. Thus, the use of optical fiber sensors has resulted be a useful way to develop protocols to inactivate microorganisms and to propose new methods for food processing.

  18. Effect of heat treatment on corrosion behavior of duplex coatings

    Directory of Open Access Journals (Sweden)

    K. Raghu Ram Mohan Reddy

    2017-01-01

    Full Text Available In the present paper, duplex WC-Co/NiCrAlY coating is coated onto Ti6Al4V substrate and vacuum heat treatment is employed to investigate the corrosion behavior of heat treated samples as well as Ti6Al4V substrate for comparison. In this duplex coating system, High Velocity Oxy Fuel (HVOF process is used to deposit NiCrAlY interlayer with a constant thickness of 200 μm and WC-Co ceramic top layer with varying thickness of 250 μm, 350 μm and 450 μm deposited by Detonation Spray (DS process. Different heat treatment temperatures (600–1150 °C were employed for the coated samples to study the microstructure and the effect on corrosion resistance of the duplex coatings. Potentiodynamic polarization tests were carried to investigate the corrosion performance of duplex coated heat treated samples and the substrate in Ringer’s solution at 37 °C and prepared the pH to 5.7. The microstructure upon corrosion after heat treatment was characterized by SEM analysis to understand the corrosion behavior. The results disclosed that at all heat treatment temperatures, all the coated samples exhibited better corrosion resistance than the base substrate. However, during 950 °C and 1150 °C heat treatment temperatures, it was observed highest corrosion potential than 600 °C and 800 °C. The 350 μm thickness, coated sample exhibited highest corrosion resistance compared to other two coated samples and the substrate at all heat treatment temperatures.

  19. Effect of heat treatment on the magnetic and magnetoelastic properties of cobalt ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Nlebedim, I.C., E-mail: nlebedimci@Cardiff.ac.u [Wolfson Centre for Magnetics, School of Engineering, Cardiff University, Cardiff CF24 3AA (United Kingdom); Ranvah, N.; Williams, P.I.; Melikhov, Y.; Snyder, J.E.; Moses, A.J.; Jiles, D.C. [Wolfson Centre for Magnetics, School of Engineering, Cardiff University, Cardiff CF24 3AA (United Kingdom)

    2010-07-15

    The influence of different heat treatments on the magnetic and magnetoelastic properties of highly magnetostrictive CoFe{sub 2}O{sub 4} has been investigated. The first order cubic anisotropy coefficient, coercive field, magnetostriction and high strain sensitivity were observed to decrease as the heat treatment temperature increased. The saturation magnetization of the samples on the other hand increased with increase in heat treatment temperature. These changes were not accompanied by any observable changes in crystal structure or composition and are indicative of migration of Co{sup 2+} from the octahedral sites (B-sites) to the tetrahedral sites (A-sites) and Fe{sup 3+} from the A-sites to the B-sites of the spinel structure. Different distributions of the cations at the two distinct lattice sites can strongly affect the magnetic and magnetoelastic properties of these materials.

  20. Effect of heat moisture treatment and annealing on physicochemical ...

    African Journals Online (AJOL)

    Red sorghum starch was physically modified by annealing and heat moisture treatment. The swelling power and solubility increased with increasing temperature range (60-90°), while annealing and heatmoisture treatment decreased swelling power and solubility of starch. Solubility and swelling were pH dependent with ...

  1. Evolution of microstructure and hardness of AE42 alloy after heat treatments

    DEFF Research Database (Denmark)

    Huang, Y.D.; Dieringa, H.; Hort, N.

    2008-01-01

    the microstructure of squeeze cast AE42 magnesium alloy and evaluates its hardness before and after heat treatments. The change in hardness is discussed based on the microstructural observations. Some suggestions are given concerning future design of alloy compositions in order to improve high temperature creep...... properties even further. It is shown that the microstructure of the squeeze-cast AE42 alloy is stable at high temperature 450 degrees C. The subsequent solution and ageing treatments have a limited effect on the hardness. The weak age-hardening is attributed to the precipitation of small amount Of Mg17Al12......-phase with the use of about 0.7 wt.% aluminum. The heat treatment to achieve a maximum increase in the hardness is: solution treatment at 450 degrees C for 5-10 h followed by an ageing treatment at 190-220 degrees C for about 5 It. (C) 2007 Elsevier B.V. All rights reserved....

  2. The Effect of Heat Treatments and Coatings on the Outgassing Rate of Stainless Steel Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Mamum, Md Abdullah A. [Old Dominion Univ., Norfolk, VA (United States); Elmustafa, Abdelmageed A, [Old Dominion Univ., Norfolk, VA (United States); Stutzman, Marcy L. [JLAB, Newport News, VA (United States); Adderley, Philip A. [JLAB, Newport News, VA (United States); Poelker, Matthew [JLAB, Newport News, VA (United States)

    2014-03-01

    The outgassing rates of four nominally identical 304L stainless steel vacuum chambers were measured to determine the effect of chamber coatings and heat treatments. One chamber was coated with titanium nitride (TiN) and one with amorphous silicon (a-Si) immediately following fabrication. One chamber remained uncoated throughout, and the last chamber was first tested without any coating, and then coated with a-Si following a series of heat treatments. The outgassing rate of each chamber was measured at room temperatures between 15 and 30 deg C following bakes at temperatures between 90 and 400 deg C. Measurements for bare steel showed a significant reduction in the outgassing rate by more than a factor of 20 after a 400 deg C heat treatment (3.5 x 10{sup 12} TorrL s{sup -1}cm{sup -2} prior to heat treatment, reduced to 1.7 x 10{ sup -13} TorrL s{sup -1}cm{sup -2} following heat treatment). The chambers that were coated with a-Si showed minimal change in outgassing rates with heat treatment, though an outgassing rate reduced by heat treatments prior to a-Si coating was successfully preserved throughout a series of bakes. The TiN coated chamber exhibited remarkably low outgassing rates, up to four orders of magnitude lower than the uncoated stainless steel. An evaluation of coating composition suggests the presence of elemental titanium which could provide pumping and lead to an artificially low outgassing rate. The outgassing results are discussed in terms of diffusion-limited versus recombination-limited processes.

  3. Effect of heat treatment of wood on the morphology, surface roughness and penetration of simulated and human blood.

    Science.gov (United States)

    Rekola, J; Lassila, L V J; Nganga, S; Ylä-Soininmäki, A; Fleming, G J P; Grenman, R; Aho, A J; Vallittu, P K

    2014-01-01

    Wood has been used as a model material for the development of novel fiber-reinforced composite bone substitute biomaterials. In previous studies heat treatment of wood was perceived to significantly increase the osteoconductivity of implanted wood material. The objective of this study was to examine some of the changing attributes of wood materials that may contribute to improved biological responses gained with heat treatment. Untreated and 140°C and 200°C heat-treated downy birch (Betula pubescens Ehrh.) were used as the wood materials. Surface roughness and the effect of pre-measurement grinding were measured with contact and non-contact profilometry. Liquid interaction was assessed with a dipping test using two manufactured liquids (simulated blood) as well as human blood. SEM was used to visualize possible heat treatment-induced changes in the hierarchical structure of wood. The surface roughness was observed to significantly decrease with heat treatment. Grinding methods had more influence on the surface contour and roughness than heat treatment. The penetration of the human blood in the 200°C heat-treated exceeded that in the untreated and 140°C heat-treated materials. SEM showed no significant change due to heat treatment in the dry-state morphology of the wood. The results of the liquid penetration test support previous findings in literature concerning the effects of heat treatment on the biological response to implanted wood. Heat-treatment has only a marginal effect on the surface contour of wood. The highly specialized liquid conveyance system of wood may serve as a biomimetic model for the further development of tailored fiber-composite materials.

  4. Field Heat Treatment Technician: Competency Profile. Apprenticeship and Industry Training. 20908.1

    Science.gov (United States)

    Alberta Advanced Education and Technology, 2008

    2008-01-01

    The graduate of the Field Heat Treatment Technician apprenticeship program is a certified journeyperson who will be able: (1) use heat treatment equipment to apply heat to materials in order to change a material's properties; (2) Use their knowledge of the properties of heat, industry codes and specifications to determine how heat treatment will…

  5. effects of heat input on the chemical composition and hardness

    African Journals Online (AJOL)

    2012-07-02

    Jul 2, 2012 ... Abstract. This study examines the thermochemical reactions which alter weld metal chemistry by applying the arc heat considering the convective, radiation and arc heat losses. From numerical analysis, it was found that the radiation heat loss was dominant in the welding process which confirms the claims ...

  6. High Thermal Conductivity Polymer Composites for Low Cost Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-08-01

    This factsheet describes a project that identified and evaluated commercially available and state-of-the-art polymer-based material options for manufacturing industrial and commercial non-metallic heat exchangers. A heat exchanger concept was also developed and its performance evaluated with heat transfer modeling tools.

  7. Influence of heat treatments on microstructure, mechanical properties, and corrosion resistance of weld alloy 625

    Science.gov (United States)

    Cortial, F.; Corrieu, J. M.; Vernot-Loier, C.

    1995-05-01

    The effects of heat treatments of the industrial type (eight-hour hold times at temperatures between 600 °C and 1000 °C) on the structural, mechanical, and corrosion resistance characteristics of weld alloy 625 have been studied. During the heat treatment, the mean concentration ratios of Nb, Mo, Si, Cr, Ni, and Fe elements between the interdendritic spaces and dendrite cores show little evolution up to 850 °C. Beyond that temperature, this ratio approximates 1, and the composition heterogeneity has practically disappeared at 1000 °C. An eight-hour heat treatment at temperatures between 650 °C and 750 °C results in increased mechanical strength values and reduced ductility and impact strength linked to the precipitation of body-centered tetragonal metastable intermetallic γ″ Ni3Nb phase in the interdendritic spaces. An eight-hour treatment in the temperature range between 750 °C and 950 °C has catastrophic effects on all mechanical characteristics in relation with the precipitation, in the interdendritic spaces, of the stable orthorhombic intermetallic δ Ni3(Nb, Mo, Cr, Fe, Ti) phase. At 1000 °C, the ductility and impact strength are restored. However, the higher the heat treatment temperature, the weaker the mechanical strength. Heat treatments have no effect on the pitting resistance of weld alloy 625 in sea water. The comparison of the results of this study on weld alloy 625 with those previously obtained on forged metal 625 shows that heat treatments below 650 °C and above 1000 °C are the sole treatments to avoid embrittlement and impairment of the corrosion resistance characteristics of alloy 625.

  8. Effect of the heat treatment conditions on the synthesis of Sr-hexaferrite

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Garcia, R., E-mail: rmartinez@fi.uba.ar [Laboratorio de Solidos Amorfos - INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires, Av. Paseo Colon 850, C1063ACV, Buenos Aires (Argentina); Bilovol, V.; Socolovsky, L.M. [Laboratorio de Solidos Amorfos - INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires, Av. Paseo Colon 850, C1063ACV, Buenos Aires (Argentina)

    2012-08-15

    The effect of heat treatment conditions under oxygen atmosphere on the SrFe{sub 12}O{sub 19} synthesis is analyzed. Effect of partial evacuation of decomposition gases of the organometallic precursor on the phase composition of different samples is studied. An accurate structural analysis of samples obtained between 250 Degree-Sign C and 600 Degree-Sign C is reported. From the structural analysis several secondary phases are identified. The amount of secondary phases can be manipulated through the control of the heat treatment conditions, and therefore, this constitutes a methodology to manipulate the composition and the magnetic properties of the obtained nanopowders. The quantitative determination of phases is performed by structural refinement of X-ray powder patterns, using Rietveld analysis. Magnetic study is done by magnetization vs. applied magnetic field at room temperature.

  9. Using geothermal energy to heat a portion of a formation for an in situ heat treatment process

    Science.gov (United States)

    Pieterson, Roelof; Boyles, Joseph Michael; Diebold, Peter Ulrich

    2010-06-08

    Methods of using geothermal energy to treat subsurface formations are described herein. Methods for using geothermal energy to treat a subsurface treatment area containing or proximate to hydrocarbons may include producing geothermally heated fluid from at least one subsurface region. Heat from at least a portion of the geothermally heated fluid may be transferred to the subsurface treatment area to heat the subsurface treatment area. At least some hydrocarbon fluids may be produced from the formation.

  10. Microstructure Evolution during Supersolvus Heat Treatment of a Powder Metallurgy Nickel-Base Superalloy

    Science.gov (United States)

    Semiatin, S. L.; McClary, K. E.; Rollett, A. D.; Roberts, C. G.; Payton, E. J.; Zhang, F.; Gabb, T. P.

    2012-05-01

    Microstructure evolution during the supersolvus heat treatment of a powder-metallurgy, low-solvus, high-refractory (LSHR) superalloy was established. For this purpose, three lots of LSHR with varying initial carbon/boron composition and thermomechanical history were subjected to a series of short-time (induction) and long-time (furnace) heat treatments followed by scanning electron microscopy/electron backscatter diffraction and quantitative metallography. The size of the (pinned) gamma grains exhibited a limited dependence on heating rate and soak time at peak temperature, and it was generally smaller than the predictions based on the classic Smith-Zener model. The differences were rationalized in terms of stereological and pinning-particle location effects. Observations of limited coarsening of the carbide/boride pinning particles were interpreted in the context of prior experimental observations and a modified Lifshitz-Slyosov-Wagner model applied previously for the coarsening of compound phases in steels.

  11. Analyzing of Nonuniform Hardness for Anchorage Clamp Plate after Heat Treatment

    Science.gov (United States)

    Liu, Zhenmin; Wang, Lijun; Ruan, Shipeng; Wang, Ningtao

    2017-09-01

    20CrMnTi wire rod can be used to manufacture the anchorage clamp plate. In the normal production, the test results show that the hardness of anchorage clamp plate is nonuniform. In this paper, the chemical composition, microstructure, grain size of clamp plate billet and the microstructure, hardness of the finished clamp plate product were studied and analyzed. The results show that improper heat treatment technics causes nonuniform hardness for anchorage clamp plate.

  12. INFLUENCE OF THERMAL HEATING ON THE FATTY ACID COMPOSITION OF TURKEY MEAT ENRICHED WITH LINSEED OIL

    Directory of Open Access Journals (Sweden)

    V. V. Gushchin

    2016-01-01

    Full Text Available Abstract The paper examines the problem of optimization of the fatty acid composition of lipids in poultry meat, which is widely used in nutrition. The omega-6 content is significantly higher than the omega-3 content in the composition of poultry meat lipids, which is not optimal for assimilation and needs a correction. The possibility of turkey meat enrichment with linseed oil was investigated with the aim of ensuring the omega-6 to omega-3 ratio in the minced meat formulations, which provides for the nutritionally adequate balance not higher than 10 units. The paper also presents the results of the investigation of the fatty acids composition and fatty acid balance of the lipid fraction of minced meat as well as the changes due to thermal heating of meat formulations in the water medium with a temperature of 95±2  °C to a product core temperature of 70±1  °C. According to the data of the investigations, the omega-6 : omega-3 ratio in the minced meat formulations before thermal treatment was 6.5 to 7.7 units compared to the control (42 units; after thermal treatment, it was 6.5 to 8.0 units for the minced meat formulations, which included vegetable oils with linseed oil. The data on the fatty acid composition of the formulations correspond to the indicators of the fatty acid balance which was RL1…3=0.47 – 0.57 and RL1…6 = 0.32 – 0.37 units for enriched minced meat before thermal treatment and 0.48 – 0.57 and 0.31 – 0.38 units after thermal treatment, respectively. The results confirm the possibility to enrich minced meat formulations with linseed oil when producing meat balls, which can be extended to other types of products.

  13. EFFECT OF HEAT TREATMENT ON SOYBEAN PROTEIN SOLUBILITY

    Directory of Open Access Journals (Sweden)

    RODICA CĂPRIŢĂ

    2007-05-01

    Full Text Available The use of soybean products in animal feeds is limited due to the presence of antinutritional factors (ANF. Proper heat processing is required to destroy ANF naturally present in raw soybeans and to remove solvent remaining from the oil extraction process. Over and under toasting of soybean causes lower nutritional value. Excessive heat treatment causes Maillard reaction which affects the availability of lysine in particular and produces changes to the chemical structure of proteins resulting in a decrease of the nutritive value. The objective of this study was to evaluate the effect of heating time on the protein solubility. The investigation of the heating time on protein solubility in soybean meal (SBM revealed a negative correlation (r = -0.9596. Since the urease index is suitable only for detecting under processed SBM, the protein solubility is an important index for monitoring SBM quality.

  14. 49 CFR 179.220-11 - Postweld heat treatment.

    Science.gov (United States)

    2010-10-01

    ... treated before welding to shell if postweld heat treatment is not practicable due to assembly procedures... SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-11...

  15. intercritical heat treatments effects on low carbon steels quenched

    African Journals Online (AJOL)

    DR B. A. EZEKOYE

    of a duplex structure comprising hard particles embedded in a soft ferrite matrix, but then differ in the way the strain is partitioned between the phases. The purpose of this work was to investigate the effect of diverse intercritical heat treatments on the mechanical properties of six low carbon steels, containing carbon with the ...

  16. Effect of heat treatment on polyphenol oxidase and peroxidase ...

    African Journals Online (AJOL)

    Effect of heat treatment (55°C/20 min) on polyphenol oxidase (PPO) and peroxidase (POD) activities and total phenolic compounds was investigated in Algerian dates (Deglet Nour variety) at Tamar (fully ripe) stage and in dates stored for 5 months at ambient temperature and in cold storage (10°C). Results obtained ...

  17. Effect of heat treatment temperature on microstructure and ...

    Indian Academy of Sciences (India)

    Administrator

    Keywords. Hollow carbon spheres; heat treatment; gas pressure; lithium ion battery. 1. Introduction. The development of portable devices in recent years has ..... project of Shanghai Municipal Education Commission and. Shanghai Education Development Foundation Science and. Technology (No. 09CG53), Science and ...

  18. Heuristic algorithms for scheduling heat-treatment furnaces of steel ...

    Indian Academy of Sciences (India)

    The scheduling of furnaces for heat-treatment of castings is of considerable interest as a large proportion of the total production time is the processing times of these ... Department of Management Studies, Indian Institute of Science, Bangalore 560 012; Singapore-MIT Alliance, School of Mechanical and Aerospace ...

  19. Changes in hydroxyapatite powder properties via heat treatment

    Indian Academy of Sciences (India)

    The properties of hydroxyaptite (HA) powder, especially its physical one, are largely influenced by the heat treatment process. Controlling of these changes is vital in deciding the suitability of applying this powder in wet processing routes for green body fabrication. Chemically, the crystallinity of the HA powder was found to ...

  20. Effects of heat treatment on density, dimensional stability and color ...

    African Journals Online (AJOL)

    The purpose of this study was to evaluate the effect of heat treatment on some physical properties and color change of Pinus nigra wood which has high industrial use potential and large growing stocks in Turkey. Wood samples which comprised the material of the study were obtained from an industrial plant. Samples were ...

  1. Research of Fiber Composite Heat Conductivity by Monte-Carlo Method

    Directory of Open Access Journals (Sweden)

    O. V. Pugachev

    2015-01-01

    Full Text Available The work objective is to evaluate the effective heat conductivity coefficient of a material with parallel cylindrical inclusions with equal diameters.Since an analytical solution of the heat conductivity equation is quite difficult, we apply a mathematical model, in which a random motion of the imaginary "heat particles" represents the process of heat conduction. These particles represent a sample of distribution, which has density being, at every moment, proportional to that of the heat energy. Thus, using the Wiener processes enables obtaining the solution of the heat conductivity equation. The velocity of "heat particles" depends on the temperature conductivity coefficient of the material in which the particles are moving at the moment.The paper considers a layer fragment of the composite material whose effective temperature conductivity coefficient is to be evaluated. As a criterion of heat conduction, we consider the probability P, assuming that a heat particle, having started from one surface of the layer, reaches its opposite surface for a time less than T. For a homogeneous isotropic material, this probability is analytically found.We perform a series of computer experiments to simulate heat conduction through a layer of the composite material, the source of heat being applied to one surface of the layer, and heat being absorbed at the opposite surface. By statistical elaboration of their results we find confidence intervals for P. Therefrom we find confidence intervals for the effective temperature conductivity coefficients (by comparing with homogeneous materials yielding the same value of P. Next, the effective heat conductivity coefficients are obtained through multiplying the effective temperature conductivity by the average volume heat capacity.We took various proportions between cylinder diameters and distances between them. The results obtained are consistent with analytical ones. The method elaborated allows finding effective

  2. Evaluation of High Temperature Composites Thermal Properties under Different Heat Flux Conditions

    Directory of Open Access Journals (Sweden)

    Ahmad Reza Bahramian

    2014-06-01

    Full Text Available The thermal protection of structures in vehicles, at instantaneous high thermal shocks, would be more effective and economically feasible among other thermal protection methods using the passive heat shields especially charring the ablative composites. The most important limitations reported are lack of compiled knowledge on designing heat shield with optimal thickness under real conditions and high surface erosion rate and low mechanical strength of char layer of a composite created by ablation process. In this paper SiAlON ceramic composites, reinforced with short carbon fiber, are identified as high performance heat shields for challenging these limitations. Ablation rate and effective thermal diffusivity at different external heat fluxes are determined and calculated using oxyacetylene flame test and modeling of temperature distributions in ablation process for evaluation of thermal protection performance and effective thermal diffusivity of this composite, as a thermal protection system. The results of this work have indicated that the carbon fiber reinforced SiAlON ceramic composite can be considered as a high ablation heat shield. Under the same condition of ablation test, SiAlON ceramic composites reinforced by carbon fiber show higher ablation performance relative to other commercial carbon fiber reinforced composite heat shields. At 8500 and 5000 kWm-2 external heat flux the ablation rates of this composite are 0.075 and 0.026 mms-1, respectively. Also, at 2500 kWm-2 external heat flux and test duration time of less than 25 s, this composite displays an adequate thermal shock protection with maximum flexural strength loss of about 23.4 %.

  3. Heat transition during magnetic heating treatment: Study with tissue models and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Henrich, Franziska [Technische Universität Dresden, Institute of Fluid Mechanics, Chair of Magnetofluiddynamics, 01062 Dresden (Germany); Max Planck Institute for Polymer Research, Physics at Interfaces, 55128 Mainz (Germany); Rahn, Helene, E-mail: helene.rahn@tu-dresden.de [Technische Universität Dresden, Institute of Fluid Mechanics, Chair of Magnetofluiddynamics, 01062 Dresden (Germany); Odenbach, Stefan [Technische Universität Dresden, Institute of Fluid Mechanics, Chair of Magnetofluiddynamics, 01062 Dresden (Germany)

    2015-04-15

    The magnetic heating treatment (MHT) is well known as a promising therapy for cancer diseases. Depending on concentration and specific heating power of the magnetic material as well as on parameters of the magnetic field, temperatures between 43 and 55 °C can be reached. This paper deals with the evaluation of heat distribution around such a heat source in a tissue model, thereby focusing on the heat transfer from tissue enriched with magnetic nanoparticles to regions of no or little enrichment of magnetic nanoparticles. We examined the temperature distribution with several tissue phantoms made of polyurethane (PUR) with similar thermal conductivity coefficient as biological tissue. These phantoms are composed of a cylinder with one sphere embedded, enriched with magnetic fluid. Thereby the spheres have different diameters in order to study the influence of the surface-to-volume ratio. The phantoms were exposed to an alternating magnetic field. The magnetically induced heat increase within the phantoms was measured with thermocouples. Those were placed at defined positions inside the phantoms. Based on the measured results a 3-dimensional simulation of each phantom was built. We achieved an agreement between the measured and simulated temperatures for all phantoms produced in this experimental study. The established experiment theoretically allows a prediction of temperature profiles in tumors and the surrounding tissue for the potential cancer treatment and therefore an optimization of e.g. the respective magnetic nanoparticles concentrations for the desirable rise of temperature. - Highlights: • Four phantoms built to measure the temperature distribution during magnetic heating. • Simulations have been carried out based on experimental data. • Measured and simulated temperature distribution for different magnetic field strength. • Temperature profiles for with ferrofluid enriched areas of different size. • Comparison of experimental and simulated data.

  4. Structural Design and Analysis of a Light-Weight Laminated Composite Heat Sink for Spaceflight PWBs

    Science.gov (United States)

    Fan, Mark S.; Niemeyer, W. Lee

    1997-01-01

    In order to reduce the overall weight in spaceborne electronic systems, a conventional metallic heat sink typically used for double-sided printed wiring boards was suggested to be replaced by light-weight and high-strength laminated composite materials. Through technology validation assurance (TVA) approach, it has been successfully demonstrated that using laminated composite heat sink can not only reduce the weight of the heat sink by nearly 50%, but also significantly lower the internal thermally-induced stresses that are largely responsible for potential delamination under cyclic temperature variations. With composite heat sink, both thermal and dynamic performance of the double-sided printed wiring board (PWB) exceeds that of its counterpart with metallic heat sink. Also included in this work is the original contribution to the understanding of creep behavior of the worst-case leadless chip carrier (LCC) surface mount solder joint. This was identified as the interconnection most susceptible to thermal fatigue damage in the PWB assembly.

  5. Change in cell surface properties of Lactobacillus casei under heat shock treatment.

    Science.gov (United States)

    Haddaji, Najla; Mahdhi, Abdel Karim; Krifi, Boubaker; Ismail, Manel Ben; Bakhrouf, Amina

    2015-05-01

    We undertake this study in the aim to give new insight about the change in cellular physiological state under heat shock treatment and probiotic strain screening procedure. Different cell properties have been studied like adhesive ability to biotic and abiotic surfaces, the cell surface hydrophobicity and the fatty acids profiles. Compared to the normal cells, the heated cells increased their adhesive ability to biotic surface. However, the adhesion to abiotic surface was decreased. The cell surface hydrophobicity of the heated strains showed a significant decrease (P Lactobacillus casei cells was significantly higher than that of the control cells (P < 0.05). The present finding could firstly add new insight about the response of probiotic to stressful conditions, such us the important role of cell membrane, considered as the first main structure to be damaged by physicochemical stress, in stress resistance because of their composition that can change in adaptation to harsh conditions. Secondly, there is no relationship between changes in membrane composition and fluidity induced by heat shock treatment and adhesion to biotic and abiotic surface. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Heat Transfer in a Concrete Composite Cross-Section

    Directory of Open Access Journals (Sweden)

    Klabník Maroš

    2016-12-01

    Full Text Available The work is concerned with the spread of heat in 2D coupled cross section with respect to the material characteristics and boundary conditions of calculation. Heat transfer was simulated in the program ANSYS in time interval up to 180 minutes. Nine various models were created to investigate the rate of influence of the changes in thermal material characteristics such as the specific heat capacity coefficient and thermal conductivity, upon the course and difference of temperature in the concrete cross-section. The comparison of results obtained using non-linear and constant values of the variables in simulation was made, too.

  7. Gear distortion analysis due to heat treatment process

    Science.gov (United States)

    Guterres, Natalino F. D. S.; Rusnaldy, Widodo, Achmad

    2017-01-01

    One way to extend the life time of the gear is minimizing the distortion during the manufacturing process. One of the most important processes in manufacturing to produce gears is heat treatment process. The purpose of this study is to analyze the distortion of the gear after heat treatment process. The material of gear is AISI 1045, and it was designed with the module (m) 1.75, and a number of teeth (z) 29. Gear was heat-treated in the furnace at a temperature of 800°C, holding time of 30 minutes, and then quenched in water. Furthermore, surface hardening process was also performed on gear teeth at a temperature of 820°C and holding time of 35 seconds and the similar procedure of analysis was conducted. The hardness of gear after heat treatment average 63.2 HRC and the teeth surface hardness after gear to induction hardening was 64.9 HRC at the case depth 1 mm. The microstructure of tested gear are martensitic and pearlite. The highest distortion on tooth thickness to upper than 0.063 can cause high precision at the tooth contact is not appropriate. Besides the shrinkage of tooth thickness will also affect to contact angle because the size of gear tolerance was not standardized.

  8. Compressive strength differences between hybrid composites using post curing light box with LED and dry heating, in vitro

    Directory of Open Access Journals (Sweden)

    Jenny Krisnawaty

    2011-11-01

    Full Text Available A hybrid type of composite resins is used as dental restorative materials in a wide cavity directly or indirectly. The mechanical properties of the composite resin would increase post-curing. The purpose of this study was to determine the differences between the compressive strength of hybrid type composite resin post-curing using LED light box and dry heating. This type of research was a quasi-experimental in vitro with the sample size of 30 samples which were divided into two groups. Each sample was tested using a Universal Testing Machine (Lloyd at a speed of 1 mm/minute to test the compressive strength. Compressive strength values were recorded when the sample broke. The average value of compressive strength of the two treatment groups was statistically calculated using t-test. The results, of this study, showed that a hybrid composite resin with post curing using a light box with LED was at 194.138 Mpa which was lower than using the dry heat of 227.339 Mpa. It showed the statistically significant difference. The conclusion of this study was that the compressive strength of post-cured hybrid composites using a light box with LED was significantly lower than the post-curing using dry heat.

  9. Optimisation of the T6 heat treatment of rheocast alloy A356

    CSIR Research Space (South Africa)

    Moller, H

    2007-11-01

    Full Text Available The heat treatment cycles that are currently applied to processed components are mostly those that are in use for traditional dendritic alloys. These heat treatments are not necessarily the optimum heat treatments for SSM processing. The T6 heat...

  10. Thermal conductivity, electrical conductivity and specific heat of copper-carbon fiber composite

    Science.gov (United States)

    Kuniya, Keiichi; Arakawa, Hideo; Kanai, Tsuneyuki; Chiba, Akio

    1988-01-01

    A new material of copper/carbon fiber composite is developed which retains the properties of copper, i.e., its excellent electrical and thermal conductivity, and the property of carbon, i.e., a small thermal expansion coefficient. These properties of the composite are adjustable within a certain range by changing the volume and/or the orientation of the carbon fibers. The effects of carbon fiber volume and arrangement changes on the thermal and electrical conductivity, and specific heat of the composite are studied. Results obtained are as follows: the thermal and electrical conductivity of the composite decrease as the volume of the carbon fiber increases, and were influenced by the fiber orientation. The results are predictable from a careful application of the rule of mixtures for composites. The specific heat of the composite was dependent, not on fiber orientation, but on fiber volume. In the thermal fatigue tests, no degradation in the electrical conductivity of this composite was observed.

  11. Thermal/Fluid Analysis of a Composite Heat Exchanger for Use on the RLV Rocket Engine

    Science.gov (United States)

    Nguyen, Dalton

    2002-01-01

    As part of efforts to design a regeneratively cooled composite nozzle ramp for use on the reusable vehicle (RLV) rocket engine, an C-SiC composites heat exchanger concept was proposed for thermal performance evaluation. To test the feasibility of the concept, sample heat exchanger panels were made to fit the Glenn Research Center's cell 22 for testing. Operation of the heat exchanger was demonstrated in a combustion environment with high heat fluxes similar to the RLV Aerospike Ramp. Test measurements were reviewed and found to be valuable for the on going fluid and thermal analysis of the actual RLV composite ramp. Since the cooling fluid for the heat exchanger is water while the RLV Ramp cooling fluid is LH2, fluid and thermal models were constructed to correlate to the specific test set-up. The knowledge gained from this work will be helpful for analyzing the thermal response of the actual RLV Composite Ramp. The coolant thermal properties for the models are taken from test data. The heat exchanger's cooling performance was analyzed using the Generalized Fluid System Simulation Program (GFSSP). Temperatures of the heat exchanger's structure were predicted in finite element models using Patran and Sinda. Results from the analytical models and the tests show that RSC's heat exchanger satisfied the combustion environments in a series of 16 tests.

  12. PREPARATION OF PUZZOLANA ACTIVE TWO COMPONENT COMPOSITE FOR LATENT HEAT STORAGE

    Directory of Open Access Journals (Sweden)

    Jan Fort

    2016-10-01

    Full Text Available Application of Phase Change Materials (PCMs represents promising way for an increase of energy efficiency of industrial devices, reduction of energy demands for heating and cooling, waste heat recovery, solar energy storage and smart control of buildings interior climate. In this paper, the potential of diatomite as the bearer for the shape stable PCM was studied in order to develop material applicable in the mix composition of composite materials. Considering availability, endurance and compatibility of diatomite with the cement and lime based materials, preparation of diatomite/wax composite brings pozzolana active PCM with great promises at a reasonable cost. Prepared composite was analysed in detail using laser diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. Also the pozzolanic activity was measured. The prepared two components composite exhibits high latent heat storage and particle size distribution compatible with cement and hydrated lime.

  13. Cleaning graphene: Comparing heat treatments in air and in vacuum

    Science.gov (United States)

    Tripathi, Mukesh; Mittelberger, Andreas; Mustonen, Kimmo; Mangler, Clemens; Kotakoski, Jani; Meyer, Jannik C.; Susi, Toma

    2017-08-01

    Surface impurities and contamination often seriously degrade the properties of two-dimensional materials such as graphene. To remove contamination, thermal annealing is commonly used. We present a comparative analysis of annealing treatments in air and in vacuum, both ex situ and "pre-situ", where an ultra-high vacuum treatment chamber is directly connected to an aberration-corrected scanning transmission electron microscope. While ex situ treatments do remove contamination, it is challenging to obtain atomically clean surfaces after ambient transfer. However, pre-situ cleaning with radiative or laser heating appears reliable and well suited to clean graphene without undue damage to its structure.

  14. Effect of heat treatment on structure and properties of multilayer Zn-Ni alloy coatings

    Directory of Open Access Journals (Sweden)

    VAISHAKA R. RAO

    2013-11-01

    Full Text Available Composition modulated multilayer alloy (CMMA coatings of Zn-Ni were electrodeposited galvanostatically on mild steel (MS for enhanced corrosion protection using single bath technique. Successive layers of Zn-Ni alloys, having alternately different composition were obtained in nanometer scale by making the cathode current to cycle between two values, called cyclic cathode current densities (CCCD’s. The coatings configuration, in terms of compositions and thicknesses were optimized, and their corrosion performances were evaluated in 5 % NaCl by electrochemical methods. The corrosion rates (CR’s of multilayer alloy coatings were found to decrease drastically (35 times with increase in number of layers (only up to 300 layers, compared to monolayer alloy deposited from the same bath. Surface study was carried with SEM, while XRD was used to determine metal lattice parameters, texture and phase composition of the coatings. The effect of heat treatment on surface morphology, thickness, hardness and corrosion behaviour of multilayer Zn-Ni alloy coatings were studied. The significant structural modification due to heat treatment is not accompanied by any decrease in corrosion rate. This effect is related to the formation of a less disordered lattice for multilayer Zn-Ni alloy coatings.

  15. Influence of Heat Treatments on Carotenoid Content of Cherry Tomatoes

    Directory of Open Access Journals (Sweden)

    Laura D'Evoli

    2013-07-01

    Full Text Available Tomatoes and tomato products are rich sources of carotenoids—principally lycopene, followed by β-carotene and lutein. The aim of this work was to study the effect of heat treatment on carotenoid content in cherry tomatoes. Raw and canned products were sampled and analysed; furthermore whole, skin and pulp fractions of cherry tomatoes were analysed when raw and home-processed, in order to better understand heat treatment effects. Lycopene content in canned tomatoes was two-fold higher than in raw tomatoes (11.60 mg/100 g versus 5.12 mg/100 g. Lutein and β-carotene were respectively 0.15 mg/100 g and 0.75 mg/100 g in canned tomatoes versus 0.11 mg/100 g and 1.00 mg/100 g in raw tomatoes. For home-processed tomatoes, β-carotene and lutein showed a content decrease in all thermally treated products. This decrease was more evident for β-carotene in the skin fraction (−17%, while for lutein it was greater in the pulp fraction (−25%. Lycopene presented a different pattern: after heat treatment its concentration increased both in the whole and in pulp fractions, while in the skin fraction it decreased dramatically (−36%. The analysis of the isomers formed during the thermal treatment suggests that lycopene is rather stable inside the tomato matrix.

  16. Influence of Heat Treatments on Carotenoid Content of Cherry Tomatoes.

    Science.gov (United States)

    D'Evoli, Laura; Lombardi-Boccia, Ginevra; Lucarini, Massimo

    2013-07-31

    Tomatoes and tomato products are rich sources of carotenoids-principally lycopene, followed by β-carotene and lutein. The aim of this work was to study the effect of heat treatment on carotenoid content in cherry tomatoes. Raw and canned products were sampled and analysed; furthermore whole, skin and pulp fractions of cherry tomatoes were analysed when raw and home-processed, in order to better understand heat treatment effects. Lycopene content in canned tomatoes was two-fold higher than in raw tomatoes (11.60 mg/100 g versus 5.12 mg/100 g). Lutein and β-carotene were respectively 0.15 mg/100 g and 0.75 mg/100 g in canned tomatoes versus 0.11 mg/100 g and 1.00 mg/100 g in raw tomatoes. For home-processed tomatoes, β-carotene and lutein showed a content decrease in all thermally treated products. This decrease was more evident for β-carotene in the skin fraction (-17%), while for lutein it was greater in the pulp fraction (-25%). Lycopene presented a different pattern: after heat treatment its concentration increased both in the whole and in pulp fractions, while in the skin fraction it decreased dramatically (-36%). The analysis of the isomers formed during the thermal treatment suggests that lycopene is rather stable inside the tomato matrix.

  17. Laboratory tests on heat treatment of ballast water using engine waste heat.

    Science.gov (United States)

    Balaji, Rajoo; Lee Siang, Hing; Yaakob, Omar; Koh, Kho King; Adnan, Faizul Amri Bin; Ismail, Nasrudin Bin; Ahmad, Badruzzaman Bin; Ismail, Mohd Arif Bin; Wan Nik, W B

    2017-05-07

    Waste heat recovery from shipboard machineries could be a potential source for heat treatment of ballast water. Similar to a shipboard schematic arrangement, a laboratory-scale engine-heat exchanger set-up harvesting waste heat from jacket water and exhaust gases was erected to test the level of species' mortalities. Mortalities were also assessed under experimental conditions for cultured and natural plankton communities at laboratory level. Effect of pump impellers on species' mortalities were also tested. Exposures between 60°C and 70°C for 60 sec resulted in 80-100% mortalities. Mortalities due to pump impeller effects were observed in the range of 70-100% for zooplankton. On the laboratory-scale arrangement, >95% mortalities of phytoplankton, zooplankton and bacteria were recorded. It was demonstrated that the temperature of tropical sea waters used as secondary coolant can be raised to cause species' mortalities, employing engine exhaust gases. The results also indicated that pump impeller effects will enhance species' mortalities. The limitations of the shipboard application of this method would be the large ballast volumes, flow rates and time for treatment.

  18. Composition of pyrolysis gas from oil shale at various stages of heating

    Science.gov (United States)

    Martemyanov, S. M.; Bukharkin, A. A.; Koryashov, I. A.; Ivanov, A. A.

    2017-05-01

    Underground, the pyrolytic conversion of an oil shale in the nearest future may become an alternative source of a fuel gas and a synthetic oil. The main scientific problem in designing this technology is to provide a methodology for determination of the optimal mode of heating the subterranean formation. Such a methodology must allow predicting the composition of the pyrolysis products and the energy consumption at a given heating rate of the subterranean formation. The paper describes the results of heating of the oil shale fragments in conditions similar to the underground. The dynamics of composition of the gaseous products of pyrolysis are presented and analyzed.

  19. Drought and heat stress effects on soybean fatty acid composition and oil stability

    Science.gov (United States)

    Previous studies have shown that oil concentration and fatty acid profile (composition) change with genotype, environment (mainly heat and drought), and geographical location. The changes in fatty acid composition under these conditions affect fatty acid stability, creating a challenge to oil proces...

  20. Aeroplastic, New Composite Materials with Reduced Heat Transfer and Increased Flame Retardancy

    Science.gov (United States)

    Williams, Martha K.; Smith, Trent M.; Nichols, James D.; Roberson, Luke B.; Tate, Lanetra C.

    2015-01-01

    A new composite system formulated using commodity grade and engineered grade polymers. The composites can be fabricated into fibers, molded, or otherwise processed into useable articles. Use of this technology reduces the thermal conductivity and peak heat releases rates of the base polymer between 20%-50% while maintaining or enhancing the mechanical properties..

  1. Temperature Evaluation of Heat Transferring Body while Preparing Temperature Chart of Heating Technologies and Metal Thermal Treatment

    Directory of Open Access Journals (Sweden)

    A. P. Nesenchuk

    2011-01-01

    Full Text Available The paper considers problems pertaining to temperature evaluation of a heat transferring body in the operational space of high temperature installations. A formula for evaluation of this temperature has been written down in the paper. Calculation of a heating transferring body (furnace makes it possible to realize temperature chart parameters in the plant heating technologies and steel thermal treatment.

  2. Graphene-Carbon-Metal Composite Film for a Flexible Heat Sink.

    Science.gov (United States)

    Cho, Hyunjin; Rho, Hokyun; Kim, Jun Hee; Chae, Su-Hyeong; Pham, Thang Viet; Seo, Tae Hoon; Kim, Hak Yong; Ha, Jun-Seok; Kim, Hwan Chul; Lee, Sang Hyun; Kim, Myung Jong

    2017-11-22

    The heat generated from electronic devices such as light emitting diodes (LEDs), batteries, and highly integrated transistors is one of the major causes obstructing the improvement of their performance and reliability. Herein, we report a comprehensive method to dissipate the generated heat to a vast area by using the new type of graphene-carbon-metal composite film as a heat sink. The unique porous graphene-carbon-metal composite film that consists of an electrospun carbon nanofiber with arc-graphene (Arc-G) fillers and an electrochemically deposited copper (Cu) layer showed not only high electrical and thermal conductivity but also high mechanical stability. Accordingly, superior thermal management of LED devices to that of conventional Cu plates and excellent resistance stability during the repeated 10 000 bending cycles has been achieved. The heat dissipation of LEDs has been enhanced by the high heat conduction in the composite film, heat convection in the air flow, and thermal radiation at low temperature in the porous carbon structure. This result reveals that the graphene-carbon-metal composite film is one of the most promising materials for a heat sink of electronic devices in modern electronics.

  3. Evaluating the Heat Pump Alternative for Heating Enclosed Wastewater Treatment Facilities in Cold Regions.

    Science.gov (United States)

    1982-05-01

    develop this procedure was obtained from site visits, technical reports and papers, and heating!/I ventilation and air conditioning (HVAC) manuals . It...Calculation Manual (1979) for many U.S., Canadian and foreign cities. Appendix A lists winter design temperatures for a few selected cities in the United...Service Capacity Construction* maintenance materiall area (1000 Btu/hr) costs ($) costs ($/yr) 1 Enclosed 2100 86,676 4,400 Treatment Area 2 Office area

  4. Optimization of size and shape of composite heat sinks with phase change materials

    Science.gov (United States)

    Balaji, C.; Mungara, Praneet; Sharma, Parw

    2011-05-01

    A composite heat sink is one in which a phase change material is interspersed with a high thermal conductivity base material to maximize the thermal performance of the device. Unlike constant area fins considered in literature, this work considers a repeating elemental composite heat sink (ECHS) with variable area fins. The base material is aluminium and the phase change material is n-Eicosane. An in house code was developed in MATLABto determine the time of operation for a vertical fins ECHS for a one dimensional approximation. This was followed by a two dimensional analysis of the problem using FLUENT 6.3. The effects of the shape of the interface surface on the time of operation and overall heat dissipated are determined and design modifications for the composite Heat Sinks based on the results obtained are suggested.

  5. The heat treatment of steel. A mathematical control problem

    Energy Technology Data Exchange (ETDEWEB)

    Hoemberg, Dietmar; Kern, Daniela

    2009-07-21

    The goal of this paper is to show how the heat treatment of steel can be modelled in terms of a mathematical optimal control problem. The approach is applied to laser surface hardening and the cooling of a steel slab including mechanical effects. Finally, it is shown how the results can be utilized in industrial practice by a coupling with machine-based control. (orig.)

  6. On ultrahigh-vacuum preparation of monocrystalline transition metal surfaces by heat treatment

    CERN Document Server

    Krakhmalev, V A; Nimatov, S J; Garafutdinova, I A; Boltaev, N N

    2002-01-01

    The composition and substructure changes in monocrystalline singular W, Mo, Nb surfaces under heat treatment have been studied in the range 30-1900 sup d egC and vacuum approx 5 centre dot 10 sup - sup 8 Pa by electronic Auger spectroscopy, optical microscopy, and X-ray methods. Under multiple thermal-cycled treatment the large carbide inclusions have been found to become the places of local surface polygonization with block disordering >=3 sup d eg. In the case of Nb annealing the carbide in the O sub 2 atmosphere has led to solving O sub 2 in sample volume. In what follows, the solute O sub 2 is found to diffuse to on the surface under heating up to maximal temperatures of the above range. Under 30 min annealing of Nb(110) at approx 550 sup d egC, sulphur (S sub 1 sub 5 sub 2) segregation on surface appears that increases with temperature. (author)

  7. Influence of heat treatment on the wear life of hydraulic fracturing tools

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Chao; Liu, Yonghong; Wang, Hanxiang; Qin, Jie; Shen, Yang; Zhang, Shihong [China University of Petroleum, Qingdao (China)

    2017-02-15

    Wear phenomenon has caused severe damage or failure of fracturing tools in oil and gas industry. In this paper, influence of heat treatment on the mechanical properties and wear resistance of fracturing tool made of lamellar graphite grey cast iron were investigated. The surface composition and microstructure were characterized by X-ray diffraction (XRD) and metallographic microscope. Sliding wear tests were performed to study the tribological behavior. Tests results showed that wear rates of treated specimens decreased by 33 %. Besides, worn morphology and wear debris were analyzed using Scanning electron microscope (SEM) and Energy dispersive Xray spectra (EDS). Wear failure mechanisms of specimens were identified. Furthermore, on-site experiment results indicated that wear loss of treated samples decreased by 37.5 %. The wear life of hydraulic fracturing tools can be improved obviously by the heat treatment.

  8. Effect of heat treatment on precipitation on V-5Cr-5Ti heat BL63

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D.S.; Li, H. [Pacific Northwest National Laboratory, Richland, WA (United States)

    1996-04-01

    The microstructures of V-5Cr-5Ti heat BL63 are compared following heat treatments at 1125{degrees}C for 1 h and 1125{degrees}C for 1 h followed by 890{degrees}C for 24 h. Following the 890{degrees}C treatment, precipitate density was increased due to the presence of a moderate density of highly elongated particles. Microchemical analysis showed that these particles often contained both Ti and V, some particles showed minor amounts of Si, S, and P, but it was also possible to show that these precipitates were enriched in O rather than C or N. Following the 1125{degrees}C heat treatment, only Si was found as a minor impurity in large particles, but S could be identified at grain boundaries, which were coated with a fine distribution of precipitates. The embrittlement observed is ascribed to a combination of interstitial solid solution hardening and grain boundary embrittlement, with interstitial hardening likely the dominant factor.

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

    Directory of Open Access Journals (Sweden)

    Namsone Eva

    2015-12-01

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

  10. THE HEAT TREATMENT ANALYSIS OF E110 CASE HARDENING STEEL

    Directory of Open Access Journals (Sweden)

    MAJID TOLOUEI-RAD

    2016-03-01

    Full Text Available This paper investigates mechanical and microstructural behaviour of E110 case hardening steel when subjected to different heat treatment processes including quenching, normalizing and tempering. After heat treatment samples were subjected to mechanical and metallographic analysis and the properties obtained from applying different processes were analysed. The heat treatment process had certain effects on the resultant properties and microstructures obtained for E110 steel which are described in details. Quenching produced a martensitic microstructure characterized by significant increase in material’s hardness and a significant decreased in its impact energy. Annealed specimens produced a coarse pearlitic microstructure with minimal variation in hardness and impact energy. For normalized samples, fine pearlitic microstructure was identified with a moderate increase in hardness and significant reduction in impact energy. Tempering had a significant effect on quenched specimens, with a substantial rise in material ductility and reduction of hardness with increasing tempering temperature. Furthermore, Results provide additional substantiation of temper embrittlement theory for low-carbon alloys, and indicate potential occurrence of temper embrittlement for fine pearlitic microstructures.

  11. New heat treatment process for advanced high-strength steels

    Science.gov (United States)

    Bublíková, D.; Jeníček, Š.; Vorel, I.; Mašek, B.

    2017-02-01

    Today’s advanced steels are required to possess high strength and ductility. It can be achieved by choosing an appropriate steel chemistry which has a substantial effect on the properties obtained by heat treatment. Mechanical properties influenced the presence of retained austenite in the final structure. Steels of this group typically require complicated heat treatment which places great demands on the equipment used. The present paper introduces new procedures aimed at simplifying the heat treatment of high-strength steels with the use of material-technological modelling. Four experimental steels were made and cast, whose main alloying additions were manganese, silicon, chromium, molybdenum and nickel. The steels were treated using the Q-P process with subsequent interrupted quenching. The resulting structure was a mixture of martensite and retained austenite. Strength levels of more than 2000 MPa combined with 10-15 % elongation were obtained. These properties thus offer potential for the manufacture of intricate closed-die forgings with a reduced weight. Intercritical annealing was obtained structure not only on the basis of martensite, but also with certain proportion of bainitic ferrite and retained austenite.

  12. PECULIARITIES OF GENERALIZATION OF SIMILAR PHENOMENA IN THE PROCESS OF FISH HEAT TREATMENT

    Directory of Open Access Journals (Sweden)

    V. A. Pokhol’chenko

    2015-01-01

    Full Text Available The theoretical presuppositions for the possibility of generalizing and similarity founding in dehydration and wet materials heating processes are studieded in this article. It is offered to carry out the given processes generalization by using dimensionless numbers of similarity. At the detailed analyzing of regularities of heat treatment processes of fish in different modes a significant amount of experienced material was successfully generalized on the basis of dimensionless simplex (similarity numbers. Using the dimensionless simplex allowed to detect a number of simple mathematical models for the studied phenomena. The generalized kinetic models of fish dehydration, the generalized dynamic models (changing moisture diffusion coefficients, the generalized kinetic models of fish heating (the temperature field changing in the products thickness, average volume and center were founded. These generalized mathematical models showed also relationship of dehydration and heating at the processes of fish semi-hot, hot smoking (drying and frying. The relationship of the results from the physical nature of the dehydration process, including a change in the binding energy of the moisture with the material to the extent of the process and the shrinkage impact on the rate of the product moisture removal is given in the article. The factors influencing the internal structure and properties of the raw material changing and retarding the dehydration processes are described there. There was a heating rate dependence of fish products on the chemical composition the geometric dimensions of the object of heating and on the coolant regime parameters. A unique opportunity is opened by using the generalized models, combined with empirically derived equations and the technique of engineering calculation of these processes, to design a rational modes of heat treatment of raw materials and to optimize the performance of thermal equipment.

  13. Effect of heat processing on the proximate composition and energy ...

    African Journals Online (AJOL)

    Dr J. T. Ekanem

    2006-08-05

    Aug 5, 2006 ... In each of these locations, heat processing generally increased moisture content of all the samples (yam, cassava products, cocoyam and maize), but decreased dry matter, crude protein, ash, crude fat, total carbohydrate and calorific value. With the exception of moisture and ash, other nutrients were ...

  14. Composite Structures Materials Testing for the Orion Crew Vehicle Heat Shield

    Science.gov (United States)

    Khemani, Farah N.

    2011-01-01

    As research is being performed for the new heat shield for the Orion capsule, National Aeronautics and Space Administration (NASA) is developing the first composite heat shield. As an intern of the Structures Branch in the Engineering Directorate (ES 2), my main task was to set up a test plan to determine the material properties of the honeycomb that will be used on the Orion Crew Module heat shield to verify that the composite is suitable for the capsule. Before conducting composite shell tests, which are performed to simulate the crush performance of the heat shield on the capsule, it is necessary to determine the compression and shear properties of the composite used on the shell. During this internship, I was responsible for developing a test plan, designing parts for the test fixtures as well as getting them fabricated for the honeycomb shear and compression testing. This involved work in Pro/Engineer as well as coordinating with Fab Express, the Building 9 Composite Shop and the Structures Test Laboratory (STL). The research and work executed for this project will be used for composite sandwich panel testing in the future as well. As a part of the Structures Branch, my main focus was to research composite structures. This involves system engineering and integration (SE&I) integration, manufacturing, and preliminary testing. The procedures for these projects that were executed during this internship included design work, conducting tests and performing analysis.

  15. Fabrication of TiCx-TiB₂/Al Composites for Application as a Heat Sink.

    Science.gov (United States)

    Shu, Shili; Yang, Hongyu; Tong, Cunzhu; Qiu, Feng

    2016-07-29

    Metal matrix composites reinforced with ceramic particles have become the most attractive material in the research and development of new materials for thermal management applications. In this work, 40-60 vol. % TiCx-TiB₂/Al composites were successfully fabricated by the method of combustion synthesis and hot press consolidation in an Al-Ti-B₄C system. The effect of the TiCx-TiB₂ content on the microstructure and compression properties of the composites was investigated. Moreover, the abrasive wear behavior and thermo-physics properties of the TiCx-TiB₂/Al composite were studied and compared with the TiCx/Al composite. The compression properties, abrasive wear behavior and thermo-physics properties of the TiCx-TiB₂/Al composite are all better than those of the TiCx/Al composite, which confirms that the TiCx-TiB₂/Al composite is more appropriate for application as a heat sink.

  16. Exploiting heat treatment effects on SMAs macro and microscopic properties in developing fire protection devices

    Science.gov (United States)

    Burlacu, L.; Cimpoeşu, N.; Bujoreanu, L. G.; Lohan, N. M.

    2017-08-01

    Ni-Ti shape memory alloys (SMAs) are intelligent alloys which demonstrate unique properties, such as shape memory effect, two-way shape memory effect, super-elasticity and vibration damping which, accompanied by good processability, excellent corrosion resistance and biocompatibility as well as fair wear resistance and cyclic stability, enabled the development of important industrial applications (such as sensors, actuators, fasteners, couplings and valves), medical applications (such as stents, bone implants, orthodontic archwires, minimal invasive surgical equipment) as well as environmental health and safety devices (anti-seismic dampers, fire safety devices). The phase transitions in Ni-Ti SMAs are strongly influenced by processing methods, chemical compositions and thermomechanical history. This paper presents a study of the effects of heat treatment on the mechanical and thermal properties of commercial Ni-Ti shape memory alloy (SMA). The experimental work involved subjecting a SMA rod to heat-treatment consisting in heating up to 500°C, 10 minutes-maintaining and water quenching. Mechanical properties were highlighted by microhardness tests while thermal characteristics were emphasized by differential scanning calorimetry (DSC). The presence of chemical composition fluctuations was checked by X-ray energy dispersive spectroscopy performed with an EDAX Bruker analyzer.

  17. Assessment of radio frequency heating on composition, microstructure, flowability and rehydration characteristics of milk powder

    Directory of Open Access Journals (Sweden)

    Yu ZHONG

    2017-10-01

    Full Text Available Abstract Radio frequency heating (RFH provides higher efficiency and more uniform heating zone compared with conventional method. The aim of present work is to evaluate the effect of RFH (at 90 °C for 5 or 10 min on the changes in composition (protein oxidation and fat distribution, microstructure, flow characteristic and rehydration property of infant milk powder. The results indicate that the concentration of protein dityrosine was slightly enhanced, more free fat appeared on powder surfaces (> 50% increase, and porosity in powder matrix as tested by SEM was increased after RFH treatment. For powder flowability, raw sample had low cohesiveness (specific energy = 4.39 mJ/g, and RFH provided better flowability and decreased compressibility. Moreover, RFH had some negative impacts on wettability and solubility of powder particles with contact angle increase at least 5% and solubility decrease of 2%~4%, indicating worse rehydration abilities. Guggenheim-Anderson-de Boer (GAB model was applied to fit moisture vapor sorption isotherms, and longer RFH duration leading to higher c values (about 63% increase at 10 min. In addition, the RFH initiated browning reaction as CIE a* values increased from -1.8 to -1.3.

  18. Effect of composition, heat treatment and processing technologies on the microstructure and properties of HP and IP rotors of large steam turbines from 1CrMoV steels

    Energy Technology Data Exchange (ETDEWEB)

    Tchizhik, A.A. [The Polzunov Central Boiler and Turbine Institute, Department the Fatigue Life of Materials for Power Plant Equipment, St. Petersburg (Russian Federation)

    1998-12-31

    In the presentation the evolution of the technology manufacturing of the large forging from the 1CrMoV steels and the results complex of the long time investigations rotors on virgin state and after different operation times is analyzed. Among the information there are the criterion of the optimization of the composition steel service properties, especially super long - term creep resistance, creep fracture and long time cracks resistance. Two safety coefficients: stress (SSC) and time safety coefficient (TSC) must be used for calculations of the possibility prolongation service life of HP and IP rotors for large steam turbines. (orig.) 11 refs.

  19. Advances in rapid cooling treatment for heat stroke

    Directory of Open Access Journals (Sweden)

    Jia-jia ZHAO

    2014-10-01

    Full Text Available Heat stroke is a life-threatening disease characterized clinically by central nervous system dysfunction and severe hyperthermia (core temperature rises to higher than 40℃. The unchecked rise of body core temperature overwhelms intrinsic or extrinsic heat generation mechanism, thus overwhelms homoeostatic thermoregulation. Hyperthermia causes cellular and organ dysfunction with progressive exacerbation resulting in multi-organ failure and death. Rapid cooling to reduce core temperature as quickly as possible is the primary and most effective treatment, as it has been shown that the major determinant of outcome in heatstroke is the degree and duration of hyperthermia. If suppression of body temperature is delayed, the fatality rate will be elevated. Several cooling methods are available, including physical cooling by conduction, convection and evaporation with ice/cold water immersion, internal cooling by invasive methods such as hemofiltration, intravascular cooling, cold water gastric and rectal lavage, and cooling with drugs. It is crucial to formulate a scientific and reasonable strategy for the subsequent treatment in accordance with the patient's physical condition, the condition of cooling equipment, and the manipulator's proficiency in cooling methods and equipment usage. This article reviews the domestic and international advances in study of rapid and efficient cooling measures for heat stroke. DOI: 10.11855/j.issn.0577-7402.2014.10.17

  20. Fully coupled heat conduction and deformation analyses of nonlinear viscoelastic composites

    KAUST Repository

    Khan, Kamran

    2012-05-01

    This study presents an integrated micromechanical model-finite element framework for analyzing coupled heat conduction and deformations of particle-reinforced composite structures. A simplified micromechanical model consisting of four sub-cells, i.e., one particle and three matrix sub-cells is formulated to obtain the effective thermomechanical properties and micro-macro field variables due to coupled heat conduction and nonlinear thermoviscoelastic deformation of a particulate composite that takes into account the dissipation of energy from the viscoelastic constituents. A time integration algorithm for simultaneously solving the equations that govern heat conduction and thermoviscoelastic deformations of isotropic homogeneous materials is developed. The algorithm is then integrated to the proposed micromechanical model. A significant temperature generation due to the dissipation effect in the viscoelastic matrix was observed when the composite body is subjected to cyclic mechanical loadings. Heat conduction due to the dissipation of the energy cannot be ignored in predicting the factual temperature and deformation fields within the composite structure, subjected to cyclic loading for a long period. A higher creep resistant matrix material or adding elastic particles can lower the temperature generation. Our analyses suggest that using particulate composites and functionally graded materials can reduce the heat generation due to energy dissipation. © 2012 Elsevier Ltd.

  1. Integration of heat treatment of wood with cogeneration production and district heating; Vaermebehandling av trae integrerad med kraftvaermeproduktion och fjaerrvaerme

    Energy Technology Data Exchange (ETDEWEB)

    Delin, Lennart; Essen, Henrik (AaF, Stockholm (Sweden))

    2011-05-15

    Heat treatment of wood changes the properties of wood so that the moisture uptake is reduced and the wood movements are reduced at variations in the ambient air humidity. The wood gets an increased resistance to rot and can therefore replace impregnated wood in certain applications. Heat treated wood is however not suitable for direct contact with soil. The strength is also reduced by heat treatment, so it is not recommended for supporting constructions. No additives whatsoever are used in the treatment, so the heat treated wood is very advantageous from an environmental point of view. The wood is dried completely at the heat treatment and heated to about 200 deg C. The question has hence been put, if it is advantageous to collocate a heat treatment plant with district heating or a power cogeneration plant. The aim of the study is to assess the value of such a collocation. Existing heat treatment plants are both few and small and the calculations have hence been made for how a large plant could be designed. A market study is included to assess the market for this type of plants. This shows that the present market for heat treated wood is very small. A full scale treatment plant of the type discussed in this study could probably not be built, since even single plants of this size would require a too large part of the market. The potential to replace impregnated wood is on the other hand very large. The cost for large scale heat treatment should be significantly lower than for impregnated wood and the cost for handling hazardous waste (which impregnated wood is classified as) is also removed. There should therefore be a potential for a future much larger volume of heat treated wood. The study shows that the energetic profit of collocation of a heat treatment plant for wood with district heating or power cogeneration plants is of lower importance. Maximally about 0.5 MSEK/year can be saved for a 25 000 m3/year plant. The initial drying of all sawn lumber has much more

  2. Effect of supplementary glycerin on milk composition and heat stability in dairy goats.

    Science.gov (United States)

    Thoh, Deela; Pakdeechanuan, Patcharin; Chanjula, Pin

    2017-12-01

    This experiment was studied the effects of various levels of crude glycerin (CG) in dairy goat diet on daily intake, milk yield, milk composition, some physical properties and some quality changes of goat milk after sterilization. Twelve 75% Saanen dairy goats (body weight = 49±3 kg; days in milk = 60±12 d) were randomly assigned in a completely randomized design to evaluate the effects of three experimental diets consisting of 0%, 5%, and 10% CG (dry matter basis) which were formulated to meet or exceed the nutrient requirements of goats. Experimental dairy goats were evaluated for feed and milk yield. Milk samples were analyzed for their composition, including fatty acids, casein profile, fat globule size, and color, and were sterilized to evaluate milk heat stability. There were no significant differences between 0% and 5% CG treatments infeed. Increasing CG supplementation from 0% to 5% increased milk yield from 2.38±0.12 to 2.64±0.23 kg/goat/d. In addition, milk samples from 5% CG treatment had the highest total solids, fat content and lactose content, and largest fat globule size. Increasing CG to 10% resulted in a decrease in milk fat. After sterilizing at 116°C, F 0 = 3 min, goat milk samples from 5% CG treatment had slightly higher sediment content and comparatively higher degree of browning. Considering milk yield, milk fat content and quality of sterilized milk, 5% CG supplementation in a total mixed ration has a potential for implementation in dairy goats.

  3. Effect of supplementary glycerin on milk composition and heat stability in dairy goats

    Directory of Open Access Journals (Sweden)

    Deela Thoh

    2017-12-01

    Full Text Available Objective This experiment was studied the effects of various levels of crude glycerin (CG in dairy goat diet on daily intake, milk yield, milk composition, some physical properties and some quality changes of goat milk after sterilization. Methods Twelve 75% Saanen dairy goats (body weight = 49±3 kg; days in milk = 60±12 d were randomly assigned in a completely randomized design to evaluate the effects of three experimental diets consisting of 0%, 5%, and 10% CG (dry matter basis which were formulated to meet or exceed the nutrient requirements of goats. Experimental dairy goats were evaluated for feed and milk yield. Milk samples were analyzed for their composition, including fatty acids, casein profile, fat globule size, and color, and were sterilized to evaluate milk heat stability. Results There were no significant differences between 0% and 5% CG treatments infeed. Increasing CG supplementation from 0% to 5% increased milk yield from 2.38±0.12 to 2.64±0.23 kg/goat/d. In addition, milk samples from 5% CG treatment had the highest total solids, fat content and lactose content, and largest fat globule size. Increasing CG to 10% resulted in a decrease in milk fat. After sterilizing at 116°C, F0 = 3 min, goat milk samples from 5% CG treatment had slightly higher sediment content and comparatively higher degree of browning. Conclusion Considering milk yield, milk fat content and quality of sterilized milk, 5% CG supplementation in a total mixed ration has a potential for implementation in dairy goats.

  4. Heat Treatment Development for a Rapidly Solidified Heat Resistant Cast Al-Si Alloy

    Science.gov (United States)

    Kasprzak, W.; Chen, D. L.; Shaha, S. K.

    2013-07-01

    Existing heat treatment standards do not properly define tempers for thin-walled castings that solidified with high solidification rates. Recently emerged casting processes such as vacuum high pressure die casting should not require long solution treatment times due to the fine microstructures arising from rapid solidification rates. The heat treatment studies involving rapidly solidified samples with secondary dendrite arm spacing between 10 and 35 μm were conducted for solution times between 30 min and 9 h and temperatures of 510 and 525 °C and for various aging parameters. The metallurgical analysis revealed that an increase in microstructure refinement could enable a reduction of solution time up to 88%. Solution treatment resulted in the dissolution of Al2Cu and Al5Mg8Si6Cu2, while Fe- and TiZrV-based phases remained partially in the microstructure. The highest strength of approximately 351 ± 9.7 and 309 ± 3.4 MPa for the UTS and YS, respectively, was achieved for a 2-step solution treatment at 510 and 525 °C in the T6 peak aging conditions, i.e., 150 °C for 100 h. The T6 temper did not yield dimensionally stable microstructure since exceeding 250 °C during in-service operation could result in phase transformation corresponding to the over-aging reaction. The microstructure refinement had a statistically stronger effect on the alloy strength than the increase in solutionizing time. Additionally, thermal analysis and dilatometer results were presented to assess the dissolution of phases during solution treatment, aging kinetics as well as dimensional stability.

  5. Control of the Size of Silver Nanoparticles and Release of Silver in Heat Treated SiO2-Ag Composite Powders

    Directory of Open Access Journals (Sweden)

    Henrika Granbohm

    2018-01-01

    Full Text Available The growth of silver nanoparticles, the activation energy for silver particle growth, and the release of silver species in heat treated SiO 2 -Ag composite powders are investigated. The silver particle growth is controlled by heat treatment for 75 min of the as-synthesized SiO 2 -Ag composite powder at 300–800 °C. During heat treatment the mean size of the Ag particles increases from 10 nm up to 61 nm with increasing temperature, however, the particle size distribution widens and the mean size increases with increasing heat treatment temperature. Based on X-ray photoelectron spectroscopy (XPS and transmission electron microscopy (TEM studies, silver particles are crystalline and in a metallic state after annealing in all SiO 2 -Ag composite powders. The growth of Ag particles is suggested to take place via diffusion and Ostwald ripening. The activation energy for particle growth was determined as 0.14 eV. The dissolution of silver in aqueous solutions from the SiO 2 -Ag composites heat treated, at 300 °C, 600 °C, and 700 °C, was investigated by varying pH and temperature. The dissolution was reduced in all conditions with increasing silver particle size, i.e., when the total surface area of Ag particles is reduced. It is suggested that the dissolution of silver from the composite powders can conveniently be adjusted by controlling the Ag particle size by the heat treatment of the composite powder.

  6. MICROSTRUCTURAL AND MECHANICAL STUDY OF ALUMINIUM ALLOYS SUBMITTED TO DISTINCT SOAKING TIMES DURING SOLUTION HEAT TREATMENT

    Directory of Open Access Journals (Sweden)

    Valmir Martins Monteiro

    2014-12-01

    Full Text Available This work studies the microstructural characteristics and mechanical properties for different aluminium alloys (1100, 3104 and 8011 hot rolled sheets that were subjected to a solution heat treatment with distinct soaking times, in order to promote microstructural and mechanical changes on these alloys with solute fractions slightly above the maximum solubility limit. Scanning Electronic Microscopy (SEM / Energy Dispersive Spectroscopy X-Ray (EDS, X-Ray Diffraction (XRD and Hardness Tests were employed to observe the microstructural / compositional and mechanical evaluation. For the 1100 and 8011 alloys the more suitable soaking time occur between 1 and 2 hours, and for the 3104 alloy occurs between 2 and 3 hours.

  7. Near field heat transfer between random composite materials. Applications and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Santiago, Eva Yazmin; Esquivel-Sirvent, Raul [Univ. Nacional Autonoma de Mexico (Mexico). Inst. de Fisica

    2017-05-01

    We present a theoretical study of the limits and bounds of using effective medium approximations in the calculation of the near field radiative heat transfer between a composite system made of Au nanoparticles in a SiC host and an homogeneous SiC slab. The effective dielectric function of the composite slab is calculated using three different approximations: Maxwell-Garnett, Bruggeman, and Looyenga's. In addition, we considered an empirical fit to the effective dielectric function by Grundquist and Hunderi. We show that the calculated value of the heat flux in the near field is dependent on the model, and the difference in the effective dielectric function is larger around the plasmonic response of the Au nanoparticles. This, in turn, accounts for the difference in the near field radiative heat flux. For all values of filling fractions, the Looyenga approximation gives a lower bound for the heat flux.

  8. Moist heat treatment on physicochemical change of chitosan salt films.

    Science.gov (United States)

    Ritthidej, Garnpimol C; Phaechamud, Thawatchai; Koizumi, Tamotsu

    2002-01-31

    Chitosan salt films were prepared by casting method using acetic, citric, formic, glycolic, lactic, malic and propionic acids as solubilizers. The films were then exposed to moist heat at 60 degrees C and 75% relative humidity for several time intervals. The influence of moist heat treatment on their physicochemical characteristics was investigated. All freshly prepared films were soluble in deionized water and HCl buffer solution. Chitosan citrate film also dissolved in phosphate buffer solution. After treatment, the percentage of water sorption and dissolution of chitosan films in three media were gradually decreased. Longer alkyl group and less carboxyl and hydroxyl groups in the molecule of organic acid resulted in lower percentage of water sorption and dissolution of treated films. The FT-IR spectra revealed that there was amide formation between chitosan and organic acids after treatment especially in chitosan acetate and propionate films. However, the absorption peaks of ammonium ['NH3+] and free carboxylate groups were still remained in treated chitosan citrate and malate films. Change in the degree of crystallinity from powder X-ray diffractogram and thermal characteristic from DSC thermogram were also related to the water sorption and dissolution of films.

  9. The Effect of Heat Treatment on Alkali Activated Materials

    Directory of Open Access Journals (Sweden)

    Girts BUMANIS

    2017-08-01

    Full Text Available The primary object of the present research was to investigate the porous low calcium alkali activated material (AAM. Traditionally Na+ ions for alkali activation solution ensure highly alkaline media which enhances the dissolution of amorphous phase in the raw materials forming solid cementitious material with sodium aluminosilicate hydrate (N-A-S-H structure afterwards. Almost all alkali ions are partially hydrated filling the pores in the gel structure (N-A-S-H gel, type zeolite precursor and neutralizing the charge on Al(OH-4 groups. These alkali ions are available for leaching in water environment. Due to this property the application of porous AAM in this research is related to the water treatment systems similar to those of natural zeolites which are considered as effective sorbent because of their porous structure, high specific surface and ion exchange. Porous AAM was obtained from metakaolin, sodium silicate glass, modified sodium silicate solution with Ms = 1.68 and diethylene glycol (DEG aluminium paste as pore forming agent. The density of AAM was 1150 ± 12 kg/m3 and compressive strength fc > 12 MPa. The effect of heat treatment to microstructure and structural properties of AAM was investigated. Heat treatment is an effective method for changing the alkali leaching kinetic form AAM structure.DOI: http://dx.doi.org/10.5755/j01.ms.23.3.16280

  10. Effects of Heat Treatment on Interface Microstructure and Mechanical Properties of Explosively Welded Ck60/St37 Plates

    Science.gov (United States)

    Yazdani, Majid; Toroghinejad, Mohammad Reza; Hashemi, Seyyed Mohammad

    2016-12-01

    This study explores the effects of heat treatment on the microstructure and mechanical properties of explosively welded Ck60 steel/St37 steel. The objective is to find an economical way for manufacturing bimetallic plates that can be used in the rolling stand of hot rolling mill units. The explosive ratio and stand-off distance are set at 1.7 and 1.5 t ( t = flyer thickness), respectively. Since explosive welding is accompanied by such undesirable metallurgical effects as remarkable hardening, severe plastic deformation, and even formation of local melted zones near the interface, heat treatment is required to overcome or alleviate these adverse effects. For this purpose, the composites are subjected to heat treatment in a temperature range of 600-700 °C at a rate of 90 °C/h for 1 h. Results demonstrate well-bonded composite plates with a wavy interface. In the as-welded case, vortex zones are formed along the interface; however, they are transformed into fine grains upon heat treatment. Microhardness is also observed to be maximum near the interface in the welded case before it decreases with increasing temperature. Shear strength is the highest in the as-welded specimen, which later decreases as a result of heat treatment. Moreover, the energy absorbed by the heat-treated specimens is observed to increase with increasing temperature so that the lowest value of absorbed energy belongs to the as-welded specimen. Finally, fractography is carried out using the scanning electron microscope to examine the specimens subjected to shear and impact tests. As a result of heat treatment, fracture surfaces exhibit dimpled ruptures and fail in the mixed mode, while failure in the as-welded specimens predominantly occurs in the brittle mode.

  11. COMPUTERIZED HEAT-TREATMENT IN A ZIMBABWEAN FACTORY

    Directory of Open Access Journals (Sweden)

    M. Collier

    2012-01-01

    Full Text Available In the context of Zimbabwe's current economic problems, parts of the manufacturing industry are turning their attention to the possibility of utilising local design talent in upgrading their manufacturing plants. This paper describes a project undertaken by the National University of Science and Technology to convert the heat-treatment process in a major manufacturing plant from semi -manual to a computerized one. The system comprises microcontroller connection to the furnaces and sensors, and communicates with a central computer on which software for a windowed user-interface is hosted. Experimental results for the system are presented, and a strategy for other companies in the same predicament is proposed.

  12. Heat regeneration of hydroxyapatite/attapulgite composite beads for defluoridation of drinking water.

    Science.gov (United States)

    Feng, Li; Xu, Weihua; Liu, Tengfei; Liu, Jason

    2012-06-30

    Regeneration is one of the key factors in evaluating an adsorbent. A novel heat regeneration method for hydroxyapatite/attapulgite (HAP/ATT) composite beads was studied. The investigation included heat regeneration temperature, regeneration time, and regeneration effects. A possible mechanism for the heat regeneration is described that explains the results of XPS, and SEM with EDAX. Exhausted HAP/ATT composite beads can be regenerated for more than 10 cycles using boiling water or steam. The total capacity increases by 10 times compared to a single defluoridation cycle. The regeneration process involves F(-) ions adsorbed on the surface of the beads to move quickly into the bulk of the HAP through the effect of heating this composite material. The surface active sites are thus re-exposed and the beads recover their fluoride sequestration properties. HAP/ATT composite beads were successfully used for the removal of fluoride from field water taken from a nearby village where fluoride contamination is endemic. Defluoridation and regeneration cycles performed in the same container provide a high efficient and simple operation. No chemical agents are used and no waste products are produced during the heat regeneration process, so this is a nearly zero emission process. This method can easily be up-scaled to a large throughput application. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Effect of heat treatment on the microstructure and the mechanical behavior of TZM alloy

    Science.gov (United States)

    Morito, Fumio

    1994-09-01

    The effect of heat treatment on the microstructure and the tensile behavior of the TZM alloys welded by an electron beam process was studied. Strength of the as-welded samples, exhibited a considerable increase. Deformation was concentrated in the weld metal and the heat affected zone due to strain localization. Postweld annealing induced a remarkable elongation by recrystallization of the base metal. Elongation of the as-welded TZM with annealing before welding was significant. ehavior described by an effective strain rate demonstrated that deformation at a very low strain rate induced a ductility of the welds. Carburization was also effective to enhance the intergranular cohesion by additional segregation and precipitation. As a result, it was found that dispersion and composition of segragates and precipitates along grain boundaries contributed to the intergranular cohesion, indicating that intergranular embrittlement can be suppressed by controlling chemical bonding at grain boundaries.

  14. Method and apparatus for real-time measurement of fuel gas compositions and heating values

    Science.gov (United States)

    Zelepouga, Serguei; Pratapas, John M.; Saveliev, Alexei V.; Jangale, Vilas V.

    2016-03-22

    An exemplary embodiment can be an apparatus for real-time, in situ measurement of gas compositions and heating values. The apparatus includes a near infrared sensor for measuring concentrations of hydrocarbons and carbon dioxide, a mid infrared sensor for measuring concentrations of carbon monoxide and a semiconductor based sensor for measuring concentrations of hydrogen gas. A data processor having a computer program for reducing the effects of cross-sensitivities of the sensors to components other than target components of the sensors is also included. Also provided are corresponding or associated methods for real-time, in situ determination of a composition and heating value of a fuel gas.

  15. Simulation of microwave heating of a composite part in an oven cavity

    Science.gov (United States)

    Tertrais, Hermine; Ibanez, Ruben; Barasinski, Anaïs; Ghnatios, Chady; Chinesta, Francisco

    2017-10-01

    Microwave (MW) technology relies on volumetric heating. Thermal energy is transferred to the material that can absorb it at specific frequencies. In this paper, a coupled thermic and electromagnetic model is proposed in order to simulate the emerging process of microwave heating for composite materials. Solving the problem in a laminated composite material requires a high degree of discretization in the thickness direction which is made possible by introducing the in-plane-out-of-plane decomposition approach using the Proper Generalized Decomposition (PGD).

  16. Studies on spin coated PANI/PMMA composite thin film: Effect of post-deposition heating

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, J.B.; Patil, R.B. [Vacuum Techniques and Thin Film Laboratory, USIC, Shivaji University, Kolhapur 416004, MS (India); Puri, R.K. [Vacuum Techniques and Thin Film Laboratory, USIC, Shivaji University, Kolhapur 416004, MS (India)], E-mail: rkp_usic@unishivaji.ac.in; Puri, Vijaya [Department of Physics, Shivaji University, Kolhapur (India)

    2008-12-30

    Adhesion, structural and optical properties of spin coated PANI/PMMA composite thin films of different composition on glass substrate are reported. The effect of post-deposition heating for 100 deg. C, 125 deg. C and 150 deg. C is also reported. The adhesion of the film was found to increase from 712 {+-} 5 x 104 N/m{sup 2} to 1602 {+-} 3 x 10{sup 4} N/m{sup 2} and refractive index decreased from 1.852 {+-} 0.005 to 1.650 {+-} 0.004 with increase in concentration of PMMA. Due to post-deposition heating adhesion, optical band gap increased but refractive index decreased.

  17. Synthesis of Mo{sub 5}SiB{sub 2} based nanocomposites by mechanical alloying and subsequent heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Abbasi, A.R. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Isfahan (Iran, Islamic Republic of); Shamanian, M., E-mail: shamanian@cc.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Isfahan (Iran, Islamic Republic of)

    2011-04-15

    Research highlights: {yields} {alpha}-Mo-Mo{sub 5}SiB{sub 2} nanocomposite was produced after 20 h milling of Mo-Si-B powders. {yields} Heat treatment of 5 h MAed powders led to the formation of boride phases. {yields} Heat treatment of 10 h MAed powders led to the formation of Mo{sub 5}SiB{sub 2} phase. {yields} By increasing heat treatment time, quantity of Mo{sub 5}SiB{sub 2} phase increased. {yields} 5 h heat treatment of 20 h MAed powders led to the formation of Mo{sub 5}SiB{sub 2}-based composite. - Abstract: In this study, systematic investigations were conducted on the synthesis of Mo{sub 5}SiB{sub 2}-based alloy by mechanical alloying and subsequent heat treatment. In this regard, Mo-12.5 mol% Si-25 mol% B powder mixture was milled for different times. Then, the mechanically alloyed powders were heat treated at 1373 K for 1 h. The phase transitions and microstructural evolutions of powder particles during mechanical alloying and heat treatment were studied by X-ray diffractometry and scanning electron microscopy. The results showed that the phase evolutions during mechanical alloying and subsequent heat treatment are strongly dependent on milling time. After 10 h of milling, a Mo solid solution was formed, but, no intermetallic phases were detected at this stage. However, an {alpha}-Mo-Mo{sub 5}SiB{sub 2} nanocomposite was formed after 20 h of milling. After heat treatment of 5 h mechanically alloyed powders, small amounts of MoB and Mo{sub 2}B were detected and {alpha}-Mo-MoB-Mo{sub 2}B composite was produced. On the other hand, heat treatment of 10 h and 20 h mechanically alloyed powders led to the formation of an {alpha}-Mo-Mo{sub 5}SiB{sub 2}-MoSi{sub 2}-Mo{sub 3}Si composite. At this point, there is a critical milling time (10 h) for the formation of Mo{sub 5}SiB{sub 2} phase after heat treatment wherein below that time, boride phase and after that time, Mo{sub 5}SiB{sub 2} phase are formed. In the case of 20 h mechanically alloyed powders, by

  18. Whisker-reinforced ceramic composites for heat engine components

    Science.gov (United States)

    Duffy, Stephen F.

    1988-01-01

    Much work was undertaken to develop techniques of incorporating SiC whiskers into either a Si3N4 or SiC matrix. The result was the fabrication of ceramic composites with ever-increasing fracture toughness and strength. To complement this research effort, the fracture behavior of whisker-reinforced ceramics is studied so as to develop methodologies for the analysis of structural components fabricated from this toughened material. The results, outlined herein, focus on the following areas: the use of micromechanics to predict thermoelastic properties, theoretical aspects of fracture behavior, and reliability analysis.

  19. Specific heat of pristine and brominated graphite fibers, composites and HOPG. [Highly Oriented Pyrolytic Graphite

    Science.gov (United States)

    Hung, Ching-Chen; Maciag, Carolyn

    1987-01-01

    Differential scanning calorimetry was used to obtain specific heat values of pristine and brominated P-100 graphite fibers and brominated P-100/epoxy composite as well as pristine and brominated highly oriented pyrolytic graphite (HOPG) for comparison. Based on the experimental results obtained, specific heat values are calculated for several different temperatures, with a standard deviation estimated at 1.4 percent of the average values. The data presented here are useful in designing heat transfer devices (such as airplane de-icing heaters) from bromine fibers.

  20. Simulation of heat transfer in intricately-configured polymer composite structures of instrumented container type

    Directory of Open Access Journals (Sweden)

    Slitkov Mikhail N.

    2017-01-01

    Full Text Available Method of mathematical simulation of heat transfer processes in polymer composite (PC products with intricate configuration, being an alternative of using up-to-date commercial software complexes has been developed. On the example of PC container with instrumentation and fiberglass electric heaters located in it, a mathematical model describing unsteady temperature field (a system of nonlinear differential heat balance equations for each element has been formulated. Features of heat transfer between elements (heaters, instrumentation, enclosing structures were taken into account. The verification of the method was conducted by comparing of theoretical temperature distributions with results of measurements in experiments with simplified variant of the structure. The developed method is effective, in particular, for such PC products as containers, modules, bunkers and vessels. It allows us to specify optimum operation modes for heating elements, operational parameters for conditioners and funs, heat insulation characteristics for providing a given level of air temperature inside objects in winter and summer service periods.

  1. Capillary-composited microfluidic device for heat shock transformation of Escherichia coli.

    Science.gov (United States)

    Sha, Jun; Wang, Yaolei; Wang, Jianchun; Ren, Li; Tu, Qin; Liu, Wenming; Wang, Xueqin; Liu, Ajing; Wang, Lei; Wang, Jinyi

    2011-10-01

    This work describes chemical heat shock transformation of foreign plasmid DNA into bacterial host Escherichia coli cells using a capillary-composited microfluidic device. Transformation processes of the loading, mixing, heat shock and recovery of the transformation mixture were carried out automatically in a linear fashion. In addition, by utilizing the capillary with a hollow cylindrical chamber as heating source, simple, low cost local heat shock with accurate heat shock time to transformation mixture was obtained on the microdevice. Results demonstrated that plasmid DNA could be effectively transformed into E. coli, and the transformation efficiency and frequency were as the same level or better than conventional tube-based method. This work complements other microfluidic technologies for potential gene cloning and functional genomics studies. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  2. Mineralogical, Spectral, and Compositional Changes During Heating of Hydrous Carbonaceous Chondrites

    Science.gov (United States)

    Nakamura, T.; Matsuoka, M.; Yamashita, S.; Sato, Y.; Mogi, K.; Enokido, Y.; Nakata, A.; Okumura, S.; Furukawa, Y.; Zolensky, M.

    2017-01-01

    Hydrous carbonaceous chondrites experienced hydration and subsequent dehydration by heating, which resulted in a variety of mineralogical and spectral features [e. g., 1-6]. The degree of heating is classified according to heating stage (HS) II to IV based on mineralogy of phyllosilicates [2], because they change, with elevating temperature, to poorly crystal-line phases and subsequently to aggregates of small secondary anhydrous silicates of mainly olivine. Heating of hydrous carbonaceous chondrites also causes spectral changes and volatile loss [3-6]. Experimental heating of Murchison CM chondrite showed flattening of whole visible-near infrared spectra, especially weakening of the 3µm band strength [1, 4, 7]. In order to understand mineralogical, spectral, and compositional changes during heating of hydrous carbonaceous chondrites, we have carried out systematic investigation of mineralogy, reflectance spectra, and volatile composition of hydrated and dehydrated carbonaceous chondrites as well as experimentally-heated hydrous carbonaceous chondrites. In addition, we investigated reflectance spectra of tochilinite that is a major phase of CM chondrites and has a low dehydration temperature (250degC).

  3. Determination of Specific Heat Capacity on Composite Shape-Stabilized Phase Change Materials and Asphalt Mixtures by Heat Exchange System.

    Science.gov (United States)

    Ma, Biao; Zhou, Xue-Yan; Liu, Jiang; You, Zhanping; Wei, Kun; Huang, Xiao-Feng

    2016-05-19

    Previous research has shown that composite shape-stabilized phase change material (CPCM) has a remarkable capacity for thermal storage and stabilization, and it can be directly applied to highway construction without leakage. However, recent studies on temperature changing behaviors of CPCM and asphalt mixture cannot intuitively reflect the thermoregulation mechanism and efficiency of CPCM on asphalt mixture. The objective of this paper is to determine the specific heat capacity of CPCM and asphalt mixtures mixed with CPCM using the heat exchange system and the data acquisition system. Studies have shown that the temperature-rise curve of 5 °C CPCM has an obvious temperature plateau, while an asphalt mixture mixed with 5 °C CPCM does not; with increasing temperature, the specific heat capacities of both 5 °C CPCM and asphalt mixture first increase and then decrease, while the variation rate of 5 °C CPCM is larger than that of the asphalt mixture, and the maximum specific heat capacity of 5 °C CPCM appears around the initial phase change temperature. It is concluded that the temperature intervals of 5 °C CPCM are -18 °C-7 °C, 7 °C-25 °C and 25 °C-44 °C, respectively, and that of the asphalt mixture are -18 °C~10 °C, -10 °C~5 °C and 5 °C~28 °C. A low dosage of 5 °C CPCM has little influence on the specific heat capacity of asphalt mixture. Finally, the functions of specific heat capacities and temperature for CPCM and asphalt mixture mixed with CPCM were recommended by the sectional regression method.

  4. Effects of heating on composition, degree of darkness, and stacking nanostructure of soil humic acids.

    Science.gov (United States)

    Katsumi, Naoya; Yonebayashi, Koyo; Okazaki, Masanori

    2016-01-15

    Wildfires and prescribed burning can affect both the quality and the quantity of organic matter in soils. In this study, we investigated qualitative and quantitative changes of soil humic substances in two different soils (an Entisol from a paddy field and an Inceptisol from a cedar forest) under several controlled heating conditions. Soil samples were heated in a muffle furnace at 200, 250, or 300 °C for 1, 3, 5, or 12h. The humic acid and fulvic acid contents of the soil samples prior to and after heating were determined. The degree of darkness, elemental composition, carbon and nitrogen stable isotope ratios, (13)C nuclear magnetic resonance spectra, and X-ray diffraction patterns of humic acids extracted from the soils before and after heating were measured. The proportion of humic acids in total carbon decreased with increasing heating time at high temperature (300 °C), but increased with increasing heating time at ≤ 250 °C. The degree of darkness of the humic acids increased with increasing heating time and temperature. During darkening, the H/C atomic ratios, the proportion of aromatic C, and the carbon and nitrogen stable isotope ratios increased, whereas the proportions of alkyl C and O-alkyl C decreased. X-ray diffraction analysis verified that a stacking nanostructure developed by heating. Changes in the chemical structure of the humic acids from the heated soils depended on the type of soil. The major structural components of the humic acids from the heated Entisol were aromatic C and carboxylic C, whereas aliphatic C, aromatic C, and carboxylic C structural components were found in the humic acids from the heated Inceptisol. These results suggest that the heat-induced changes in the chemical structure of the humic acids depended on the source plant. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Effect of Post-weld Heat Treatment on the Mechanical Properties of Supermartensitic Stainless Steel Deposit

    Science.gov (United States)

    Zappa, Sebastián; Svoboda, Hernán; Surian, Estela

    2017-02-01

    Supermartensitic stainless steels have good weldability and adequate tensile property, toughness and corrosion resistance. They have been developed as an alternative technology, mainly for oil and gas industries. The final properties of a supermartensitic stainless steel deposit depend on its chemical composition and microstructure: martensite, tempered martensite, ferrite, retained austenite and carbides and/or nitrides. In these steels, the post-weld heat treatments (PWHTs) are usually double tempering ones, to ensure both complete tempering of martensite and high austenite content, to increase toughness and decrease hardness. The aim of this work was to study the effect of post-weld heat treatments (solution treatment with single and double tempering) on the mechanical properties of a supermartensitic stainless steel deposit. An all-weld metal test coupon was welded according to standard ANSI/AWS A5.22-95 using a GMAW supermartensitic stainless steel metal cored wire, under gas shielding. PWHTs were carried out varying the temperature of the first tempering treatment with and without a second tempering one, after solution treatment. All-weld metal chemical composition analysis, metallurgical characterization, hardness and tensile property measurements and Charpy-V tests were carried out. There are several factors which can be affected by the PWHTs, among them austenite content is a significant one. Different austenite contents (0-42%) were found. Microhardness, tensile property and toughness were affected with up to 15% of austenite content, by martensite tempering and carbide precipitation. The second tempering treatment seemed not to have had an important effect on the mechanical properties measured in this work.

  6. Copper matrix composites as heat sink materials for water-cooled divertor target

    Directory of Open Access Journals (Sweden)

    Jeong-Ha You

    2015-12-01

    Full Text Available According to the recent high heat flux (HHF qualification tests of ITER divertor target mock-ups and the preliminary design studies of DEMO divertor target, the performance of CuCrZr alloy, the baseline heat sink material for DEMO divertor, seems to only marginally cover the envisaged operation regime. The structural integrity of the CuCrZr heat sink was shown to be affected by plastic fatigue at 20 MW/m². The relatively high neutron irradiation dose expected for the DEMO divertor target is another serious concern, as it would cause significant embrittlement below 250 °C or irradiation creep above 350 °C. Hence, an advanced design concept of the divertor target needs to be devised for DEMO in order to enhance the HHF performance so that the structural design criteria are fulfilled for full operation scenarios including slow transients. The biggest potential lies in copper-matrix composite materials for the heat sink. In this article, three promising Cu-matrix composite materials are reviewed in terms of thermal, mechanical and HHF performance as structural heat sink materials. The considered candidates are W particle-reinforced, W wire-reinforced and SiC fiber-reinforced Cu matrix composites. The comprehensive results of recent studies on fabrication technology, design concepts, materials properties and the HHF performance of mock-ups are presented. Limitations and challenges are discussed.

  7. Evaluation of conjugate, radial heat transfer in an internally insulated composite pipe

    NARCIS (Netherlands)

    Reurings, C.; Koussios, S.; Bergsma, O.K.; Vergote, K.

    2015-01-01

    In order to compete with steel, a fibre-reinforced composite exhaust wall with a general-purpose resin system requires an effective but lightweight insulation layer. However a lack of experimental methods for heat transfer from turbulent gas flow to pipe walls lined with a porous insulation layer

  8. Periodic composites: quasi-uniform heat conduction, Janus thermal illusion, and illusion thermal diodes

    Science.gov (United States)

    Xu, Liujun; Jiang, Chaoran; Shang, Jin; Wang, Ruizhe; Huang, Jiping

    2017-11-01

    Manipulating thermal conductivities at will plays a crucial role in controlling heat flow. By developing an effective medium theory including periodicity, here we experimentally show that nonuniform media can exhibit quasi-uniform heat conduction. This provides capabilities in proposing Janus thermal illusion and illusion thermal rectification. For the former, we study, via experiment and theory, a big periodic composite containing a small periodic composite with circular or elliptic particles. As a result, we reveal the Janus thermal illusion that describes the whole periodic system with both invisibility illusion along one direction and visibility illusion along the perpendicular direction, which is fundamentally different from the existing thermal illusions for misleading thermal detection. Further, the Janus illusion helps to design two different periodic systems that both work as thermal diodes but with nearly the same temperature distribution, heat fluxes and rectification ratios, thus being called illusion thermal diodes. Such thermal diodes differ from those extensively studied in the literature, and are useful for the areas that require both thermal rectification and thermal camouflage. This work not only opens a door for designing novel periodic composites in thermal camouflage and heat rectification, but also holds for achieving similar composites in other disciplines like electrostatics, magnetostatics, and particle dynamics.

  9. Relationship Between Mechanical Properties of Lead-Free Solders and Their Heat Treatment Parameters

    Science.gov (United States)

    Klasik, A.; Sobczak, N.; Pietrzak, K.; Makowska, K.; Wojciechowski, A.; Kudyba, A.; Sienicki, E.

    2012-05-01

    The research was undertaken to establish mechanical properties of as-cast and heat-treated Sn-Zn-based alloys of binary and ternary systems as candidates for lead (Pb)-free solder materials for high-temperature applications. The heat treatment of as-cast alloys was made under different combinations of processing parameters (168 h/50 °C, 42 h/80 °C, and 24 h/110 °C). The systematic study of structure-property relationships in Sn-Zn, Sn-Zn-Ag, and Sn-Zn-Cu alloys containing the same amount of Zn (4.5, 9, 13.5 wt.%) and 1 wt.% of either Ag or Cu was conducted to identify the effects of chemical composition and heat treatment processing parameters on the alloy microstructure and mechanical behavior. Structural characterization was made using optical microscopy and scanning electron microscopy techniques coupled with EDS analysis. Mechanical properties (initial Young's modulus E, ultimate tensile strength UTS, elastic limit R 0.05, yield point R 0.2, elongation A 5, and necking Z) were determined by means of static tensile tests. All the examined Sn-Zn-based alloys have attractive combination of mechanical characteristics, especially tensile strength, having values higher than that of common leaded solders and their substitutes of Pb-free SAC family. The results obtained demonstrate that the Sn-Zn-based alloys present competitive Pb-free solder candidates for high-temperature applications.

  10. 76 FR 3077 - Notice of Decision To Revise a Heat Treatment Schedule for Emerald Ash Borer

    Science.gov (United States)

    2011-01-19

    ... use hot water to produce heat. That design limits the internal temperature of the kiln to... Animal and Plant Health Inspection Service Notice of Decision To Revise a Heat Treatment Schedule for... are advising the public of our decision to revise a heat treatment schedule for the emerald ash borer...

  11. Effect of pre-cooling and heat treatment on antioxidant enzymes ...

    African Journals Online (AJOL)

    Similarly, application of postharvest quarantine heat treatment (52-55 °C) for 5 minutes to mango showed no heat injury (HI) symptoms like skin scalding, damaged lenticels which could be due to very short duration of exposure. Extent of recommendation of pre-cooling temperature and heat treatment of these fruits after ...

  12. Heat Recovery Apparatus for the Local Air Treatment

    OpenAIRE

    Burlacu, Andrei; Mateescu, Theodor

    2009-01-01

    The present paper presents a heat-recovery apparatus with heat pipes, originally designed by the authors for the controlled mechanical ventila-tion systems to ensure the comfort in the insulated buildings. The paper highlights a close correlation between the heat pipes heat exchangers and the concepts of thermal comfort, energy economy, environment, etc.

  13. Heat Recovery Apparatus for the Local Air Treatment

    Directory of Open Access Journals (Sweden)

    Theodor Mateescu

    2009-01-01

    Full Text Available The present paper presents a heat-recovery apparatus with heat pipes, originally designed by the authors for the controlled mechanical ventila-tion systems to ensure the comfort in the insulated buildings. The paper highlights a close correlation between the heat pipes heat exchangers and the concepts of thermal comfort, energy economy, environment, etc.

  14. Multiple Sclerosis Functional Composite as a Measure of the Effects of Heat in Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Ryosa

    2016-06-01

    Full Text Available Background Heat sensitivity is a common feature of multiple sclerosis (MS, and heat has been found to impair MS patients’ physical and cognitive functioning. There is, however, no simple and specific measurement tool to evaluate the possible effects of heat on these functions. Objectives The aim of this study was to evaluate the compatibility of the multiple sclerosis functional composite (MSFC to demonstrate the effects of heat on functioning in patients with MS. Patients and Methods A total of 22 heat-sensitive MS patients and 19 healthy controls (HCs were considered for the analysis. Moderate heat exposure took place in a Finnish sauna. Functioning was measured with the MSFC, which consists of two physical (the Nine Hole Peg test and the 25-foot timed walk test and one cognitive (the PASAT-3 measure, before, during and one hour after the heat exposure. Results In the MS group the average MSFC scores were -0.48 (SD 0.79 at baseline, -0.99 (SD 1.97 during heat exposure and -0.68 (SD 1.58 after a one-hour delay. The average MSFC scores of the HC group were 0.58 (SD 0.42 at baseline, 0.66 (SD 0.43 during heat exposure and 0.68 (SD 0.41 after a one-hour delay. The MS group had significantly lower MSFC scores than the HC group (P = 0.01. The MS patients’ score deteriorated during the heat exposure, whereas that of the controls did not (P = 0.00. Conclusions The results suggest that the MSFC could be used as a simple tool to detect the negative effects of heat in patients with MS.

  15. Effects of heating on composition, degree of darkness, and stacking nanostructure of soil humic acids

    Energy Technology Data Exchange (ETDEWEB)

    Katsumi, Naoya, E-mail: n-katsu@ishikawa-pu.ac.jp; Yonebayashi, Koyo; Okazaki, Masanori

    2016-01-15

    Wildfires and prescribed burning can affect both the quality and the quantity of organic matter in soils. In this study, we investigated qualitative and quantitative changes of soil humic substances in two different soils (an Entisol from a paddy field and an Inceptisol from a cedar forest) under several controlled heating conditions. Soil samples were heated in a muffle furnace at 200, 250, or 300 °C for 1, 3, 5, or 12 h. The humic acid and fulvic acid contents of the soil samples prior to and after heating were determined. The degree of darkness, elemental composition, carbon and nitrogen stable isotope ratios, {sup 13}C nuclear magnetic resonance spectra, and X-ray diffraction patterns of humic acids extracted from the soils before and after heating were measured. The proportion of humic acids in total carbon decreased with increasing heating time at high temperature (300 °C), but increased with increasing heating time at ≤ 250 °C. The degree of darkness of the humic acids increased with increasing heating time and temperature. During darkening, the H/C atomic ratios, the proportion of aromatic C, and the carbon and nitrogen stable isotope ratios increased, whereas the proportions of alkyl C and O-alkyl C decreased. X-ray diffraction analysis verified that a stacking nanostructure developed by heating. Changes in the chemical structure of the humic acids from the heated soils depended on the type of soil. The major structural components of the humic acids from the heated Entisol were aromatic C and carboxylic C, whereas aliphatic C, aromatic C, and carboxylic C structural components were found in the humic acids from the heated Inceptisol. These results suggest that the heat-induced changes in the chemical structure of the humic acids depended on the source plant. - Highlights: • Darkness of humic acids increased with increasing heating time and temperature. • Aromatic carbon content increased during darkening. • Carbon and nitrogen stable isotope

  16. The empirical evaluation of thermal conduction coefficient of some liquid composite heat insulating materials

    Science.gov (United States)

    Anisimov, M. V.; Rekunov, V. S.; Babuta, M. N.; Bach Lien, Nguyen Thi Hong

    2016-02-01

    We experimentally determined the coefficients of thermal conductivity of some ultra thin liquid composite heat insulating coatings, for sample #1 λ = 0.086 W/(m·°C), for sample #2 λ = 0.091 W/(m·°C). We performed the measurement error calculation. The actual thermal conduction coefficient of the studied samples was higher than the declared one. The manufactures of liquid coatings might have used some "ideal" conditions when defining heat conductivity in the laboratory or the coefficient was obtained by means of theoretical solution of heat conduction problem in liquid composite insulating media. However, liquid insulating coatings are of great interest to builders, because they allow to warm objects of complex geometric shapes (valve chambers, complex assemblies, etc.), which makes them virtually irreplaceable. The proper accounting of heating qualities of paints will allow to avoid heat loss increase above the specified limits in insulated pipes with heat transfer materials or building structures, as well as protect them from possible thawing in the period of subzero weather.

  17. Effect of pre-heating on the viscosity and microhardness of a resin composite.

    LENUS (Irish Health Repository)

    Lucey, S

    2010-04-01

    The effect of pre-heating resin composite on pre-cured viscosity and post-cured surface hardness was evaluated. Groups of uncured specimens were heated to 60 degrees C and compared with control groups (24 degrees C) with respect to viscosity and surface hardness. Mean (SD) viscosities of the pre-heated specimens (n = 15) were in the range of 285 (13)-377 (11) (Pa) compared with 642 (35)-800 (23) (Pa) at ambient temperature. There was a statistically significant difference between the two groups (P < 0.001). Mean (SD) Vickers microhardness (VHN) of the pre-heated group (n = 15) was 68.6 (2.3) for the top surface and 68.7 (1.8) for the bottom surface measured at 24 h post curing (specimen thickness = 1.5 mm). The corresponding values for the room temperature group were 60.6 (1.4) and 59.0 (3.5). There was a statistically significant difference between corresponding measurements taken at the top and bottom for the pre-heated and room temperature groups (P < 0.001). There was no significant difference between top and bottom measurements within each group. Pre-heating resin composite reduces its pre-cured viscosity and enhances its subsequent surface hardness. These effects may translate as easier placement together with an increased degree of polymerization and depth-of-cure.

  18. Gas injection to inhibit migration during an in situ heat treatment process

    Energy Technology Data Exchange (ETDEWEB)

    Kuhlman, Myron Ira (Houston, TX); Vinegar; Harold J. (Bellaire, TX); Baker, Ralph Sterman (Fitchburg, MA); Heron, Goren (Keene, CA)

    2010-11-30

    Methods of treating a subsurface formation are described herein. Methods for treating a subsurface treatment area in a formation may include introducing a fluid into the formation from a plurality of wells offset from a treatment area of an in situ heat treatment process to inhibit outward migration of formation fluid from the in situ heat treatment process.

  19. Effect of erythrocyte heat treatment on pulmonary vascular resistance.

    Science.gov (United States)

    Hakim, T S

    1994-07-01

    The effect of red blood cell deformability on the pulmonary vascular resistance was studied in isolated dog and rat lungs. Blood cells were incubated at 49 degrees C for 1 hr, to render them rigid. The resistance to blood flow in the lung was assessed either by calculating the pulmonary vascular resistance (PVR = arterial - venous pressure difference divided by flow rate) or by examining the vascular pressure-flow relationship for changes in slope and intercept. The resistance in the lung was first assessed during perfusion with normal blood and again during perfusion with rigid cells. The results showed that PVR in dog lungs increased by 15% during perfusion with heat-treated blood and that this increase in PVR was associated with a significant increase in the middle segment resistance (arterial-venous occlusion technique) and with an increase in critical closing pressure (pressure intercept of the pressure-flow curve). In contrast to the small effect in dog lungs, the PVR in rat lungs rose more than 400% during perfusion with heat-treated blood. The marked increase of PVR in rat lungs was prevented with papaverine (PVR increased only 58%), suggesting that vasoconstriction was a primary event in rat lungs. The rise in vascular resistance in rat lungs was further shown to be primarily due to the presence of rigid erythrocytes (RBC). The increase in PVR in the rat lungs was not due to mechanical obstruction of the vasculature but rather to constriction of arteries and veins (double occlusion technique). The conclusion from this study is that RBC deformability plays an important role in the pulmonary vasculature, primarily because of release of vasoactive substances and partially because of the potential mechanical obstruction of capillaries. These events are apparently species dependent and are attributed mostly to red blood cell deformability which decreases during heat treatment.

  20. Structural ordering of Pennsylvania anthracites on heat treatment to 2000-2900{sup o}C

    Energy Technology Data Exchange (ETDEWEB)

    J.V. Atria; F. Rusinko Jr.; H.H. Schobert [Pennsylvania State University, University Park, PA (United States). Energy Institute

    2002-12-01

    Three Pennsylvania anthracites from the Penn State Coal Sample Bank and Data Base were heat-treated to temperatures to 2900{sup o}C. The products were characterized by X-ray diffraction. These anthracites clearly differ in the extent to which they transform to a graphitic structure by heat treatment at ambient pressure. Graphitizability, based on approach of interlayer spacing to the ideal value for graphite and development of crystallite height, is in the order DECS 21 {gt} PSOC 1461 {gt} PSOC 1468. By 2700{sup o}C the interlayer spacing is largely established, since improvements by increasing graphitization temperature to 2900{sup o}C are small. The crystallite stacking continues to develop; significant changes are achieved at 2900 vs 2700{sup o}C. The structural changes can be related to composition via two factors. In heat treatment to 2000{sup o}C, the structural ordering may be impeded by a 'locking' of aromatic sheets in place by cross-linkers, such as oxygen atoms. At the higher temperatures, i.e., 2700 and 2900{sup o}C, the ease of rearrangement of aromatic sheets, which is related to their size, is the dominant issue. The relative sizes of aromatic sheets can be approximated from the net hydrogen content of the anthracites. DECS-21, which has both the highest oxygen content and the highest net hydrogen value, shows the least order after heat treatment to 2000{sup o}C, but the best structural development after reaction at 2700 or 2900{sup o}C. 38 refs., 2 tabs.

  1. [The influence of heat treatment on retention force of magnetic attachments].

    Science.gov (United States)

    Zhuang, Wen-jie; Weng, Wei-min

    2011-10-01

    To study the influence of heat treatment on retention force of magnetic attachments. Three groups of magnetic attachments (including 10 Magfit EX 400W, 10 Magfit EX 600W, 10 Magfit EX 800W) were fixed on universal test machine respectively. The retention force of each attachment was measured. After heat treatment, their retention force was measured again. The difference of retention force before and after heat treatment was compared using SPSS11.0 software package. The average retention force of magnetic attachments (Magfit EX 400W) was (1.58±0.12)N before heat treatment and (1.64±0.11)N after heat treatment. The average retention force of magnetic attachments (Magfit EX 600W) was (2.67±0.19)N before heat treatment and (2.65±0.14)N after heat treatment.The average retention force of magnetic attachments (Magfit EX 800W) was (3.02±0.25)N before heat treatment and (3.02±0.24)N after heat treatment. The retention force of magnetic attachments had no significant change after heat treatment (P>0.05). The magnetic attachments can be treated by waterbath heart treatment in the clinic without significant change of their retention force.

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

    Science.gov (United States)

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

    2013-10-15

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

  3. Cooling methods used in the treatment of exertional heat illness.

    Science.gov (United States)

    Smith, J E

    2005-08-01

    To review the different methods of reducing body core temperature in patients with exertional heatstroke. The search strategy included articles from 1966 to July 2003 using the databases Medline and Premedline, Embase, Evidence Based Medicine (EBM) reviews, SPORTDiscus, and cross referencing the bibliographies of relevant papers. Studies were included if they contained original data on cooling times or cooling rates in patients with heat illness or normal subjects who were subjected to heat stress. In total, 17 papers were included in the analysis. From the evidence currently available, the most effective method of reducing body core temperature appears to be immersion in iced water, although the practicalities of this treatment may limit its use. Other methods include both evaporative and invasive techniques, and the use of chemical agents such as dantrolene. The main predictor of outcome in exertional heatstroke is the duration and degree of hyperthermia. Where possible, patients should be cooled using iced water immersion, but, if this is not possible, a combination of other techniques may be used to facilitate rapid cooling. There is no evidence to support the use of dantrolene in these patients. Further work should include a randomised trial comparing immersion and evaporative therapy in heatstroke patients.

  4. Tailoring carbon nanotube density for modulating electro-to-heat conversion in phase change composites.

    Science.gov (United States)

    Liu, Zhenpu; Zou, Ruqiang; Lin, Zhiqiang; Gui, Xuchun; Chen, Renjie; Lin, Jianhua; Shang, Yuanyuan; Cao, Anyuan

    2013-09-11

    We report a carbon nanotube array-encapsulated phase change composite in which the nanotube distribution (or areal density) could be tailored by uniaxial compression. The n-eicosane (C20) was infiltrated into the porous array to make a highly conductive nanocomposite while maintaining the nanotube dispersion and connection among the matrix with controlled nanotube areal density determined by the compressive strains along the lateral direction. The resulting electrically conductive composites can store heat at driven voltages as low as 1 V at fast speed with high electro-to-heat conversion efficiencies. Increasing the nanotube density is shown to significantly improve the polymer crystallinity and reduce the voltage for inducing the phase change process. Our results indicate that well-organized nanostructures such as the nanotube array are promising candidates to build high-performance phase change composites with simplified manufacturing process and modulated structure and properties.

  5. Structural transitions in alumina nanoparticles by heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Nirmal; Khanna, Atul, E-mail: atul.phy@gndu.ac.in [Glass Physics and Sensors Laboratory, Department of Physics, Guru Nanak Dev University, Amritsar-143005, Punjab (India); Chen, Banghao [Department of Chemistry & Biochemistry, Florida State University, Tallahassee, FL 32306-4390 (United States); González, Fernando [Department of Chemistry and Process & Recourse Engineering, University of Cantabria, Santander-39005 (Spain)

    2016-05-23

    γ-alumina nanoparticles were annealed sequentially at 800°C, 950°C and 1100°C and structural transitions as a function of heat treatment were studied by X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC) and {sup 27}Al Magic Angle Spinning Nuclear Magnetic Resonance (MAS-NMR) methods.. XRD studies found that γ-Al{sub 2}O{sub 3} is stable upto a temperature of at least 950°C and transforms to the thermodynamically stable α-phase after annealing at 1100°C. MAS-NMR revealed that γ-alumina contains AlO{sub 4} and AlO{sub 6} structural units in the ratio 1: 2, while α-phase contains only AlO{sub 6} units. DSC confirmed that γ → α transition initiates at 1060°C.

  6. A study of the effects of prior heat treatment on the skin reaction of mouse feet after heat alone or combined with X-rays: influence of misonidazole

    NARCIS (Netherlands)

    Wondergem, J.; Haveman, J.

    1984-01-01

    The skin of mouse feet was used to study the effects of hyperthermic treatment, either alone or combined with irradiation. The present experiments show that a priming heat treatment induces resistance both to a subsequent heat treatment and to a subsequent combined irradiation-heat treatment. The

  7. Heat Treatment in High Chromium White Cast Iron Ti Alloy

    Directory of Open Access Journals (Sweden)

    Khaled M. Ibrahim

    2014-01-01

    Full Text Available The influence of heat treatment on microstructure and mechanical properties of high chromium white cast iron alloyed with titanium was investigated. The austenitizing temperatures of 980°C and 1150°C for 1 hour each followed by tempering at 260°C for 2 hours have been performed and the effect of these treatments on wear resistance/impact toughness combination is reported. The microstructure of irons austenitized at 1150°C showed a fine precipitate of secondary carbides (M6C23 in a matrix of eutectic austenite and eutectic carbides (M7C3. At 980°C, the structure consisted of spheroidal martensite matrix, small amounts of fine secondary carbides, and eutectic carbides. Titanium carbides (TiC particles with cuboidal morphology were uniformly distributed in both matrices. Irons austenitized at 980°C showed relatively higher tensile strength compared to those austenitized at 1150°C, while the latter showed higher impact toughness. For both cases, optimum tensile strength was reported for the irons alloyed with 1.31% Ti, whereas maximum impact toughness was obtained for the irons without Ti-addition. Higher wear resistance was obtained for the samples austenitized at 980°C compared to the irons treated at 1150°C. For both treatments, optimum wear resistance was obtained with 1.3% Ti.

  8. Comparison of bond strength of composite and acrylic teeth to heat-cured and

    Directory of Open Access Journals (Sweden)

    Amirjan A

    2011-02-01

    Full Text Available "nBackground and Aims: Failure of bonding between artificial teeth and denture base material is a considerable problem for patients who wear dentures. Because of the cost of denture repair and the expensive price of foreign artificial teeth, this study was designed to compare the bond strength of composite and acrylic artificial teeth with heat-cured and auto-polymerized denture base resins."nMaterials and Methods: In this experimental and in vitro study, two type of acrylic resin (heat-cured: Selectaplus H/ Trevalon, Dentsply and auto-polymerized: Rapid Repair, Dentsply and four artificial teeth (acrylic Marjan New, composite Glamour teeth which both of them are Iranian and Ivoclar acrylic and composite teeth were used. Therefore, 8 groups of 14 specimens each were evaluated. A shear bond strenghth test in a Universal Testing Machine was used. Data were analyzed using the 2-way ANOVA test."nResults: The bond strengths of acrylic teeth (Marjan New and Ivoclar to heat-cured resin were similar (P=0.632 and statistically higher than those of composite teeth (Glamour and Ivoclar. Acrylic teeth (Marjan New and Ivoclar and Glamour teeth had similar bond strength to auto-polymerized resin, which showed the highest bond strength values. Ivoclar composite teeth showed significantly the lowest bond strength (P<0.05. All acrylic teeth had the highest mean bond strengths to heat-cured resin which were significantly different from that of "nauto-polymerized resin (P<0.05. However, the bond strengths of all composite teeth to both denture base resins were not significantly different (P>0.05."nConclusion: Based on the results of this study, the type of denture base material and artificial tooth may influence the failure load.

  9. Effect of heating on oxidation stability and fatty acid composition of microwave roasted groundnut seed oil.

    Science.gov (United States)

    Abbas Ali, M; Anowarul Islam, M; Othman, Noor Hidayu; Noor, Ahmadilfitri Md

    2017-12-01

    The oxidative stability and fatty acid composition of groundnut seed oil (GSO) exposed to microwaves were evaluated during heating at 170 °C. During heating, the oxidative indices such as free fatty acid, peroxide value, p -anisidine value, TOTOX, thiobarbituric acid value, specific extinctions, and color value were increased. The increments were found to be higher in unroasted seed oils compared to roasted ones indicating lower release of lipid oxidation products in roasted GSO. After 9 h heating, the relative content of polyunsaturated fatty acid (PUFA) decreased to 89.53% and that of saturated fatty acid (SFA) increased to 117.46% in unroasted sample. The relative content of PUFA decreased to 92.05% and that of SFA increased to 105.76% in 7.5 min roasted sample after 9 h of heating. However, the roasting process slowed down the oxidative deterioration of PUFA. With increased heating times, an appreciable loss was more apparent in the triacylglycerol species OLL and OOL in unroasted samples compared to roasted ones. In FTIR, the peak intensities in unroasted samples were markedly changed in comparison with roasted samples during heating. The roasting of groundnut seed prior to the oil extraction reduced the oxidative degradation of oil samples; thereby increasing heat stability.

  10. Influence of heat treatment on the high temperature oxidation mechanisms of an Fe-TiCN cermet

    OpenAIRE

    Alvaredo Olmos, Paula; Abajo Clemente, Carolina; Tsipas, Sophia Alexandra; Gordo Odériz, Elena

    2014-01-01

    In this study, the oxidation behaviour of an iron matrix cermet containing 50 % vol. Ti(C,N) was investigated before and after heat treatment by oxidation tests performed in static air at temperatures between 500 °C and 1000 °C. The oxidation mechanism for this type of composite materials was established and it was found that the heat treated material presents lower mass gain than the as-sintered material at the early stages of the oxidation, due to the volatilization of oxides. The oxidation...

  11. [Reduction of the immunological rejection in composite tissue allotransplantation by heat stress preconditioning].

    Science.gov (United States)

    Schorr, N; Sauerbier, M; Germann, G; Gebhard, M M; Ofer, N

    2011-12-01

    In spite of great advances in the field of composite tissue allotransplantations (CTA), there is still a major need for optimisation in terms of immunosuppression. Heat shock proteins are produced as a reaction of the body during a stress situation. Once elevated, they protect against a second stress and reduce ischaemia-reperfusion injury within transplantations. In the literature the effect of heat shock and HSP70 on rejection after CTA has not been described. The purpose of this experimental study was to examine the effect of heat shock proteins on rejection in a rat model of CTA. Evaluated was the effect of preconditioning by prior heat stress. Brown Norway rats were systemically heated to a core temperature of 42 °C in order to up-regulate HSP70. The expression of HSP70 in muscle was measured by Western blot analysis and showed a peak 24 h after heat shock. Allogeneic hindlimb transplantations were performed between Brown Norway rats (donor) and Lewis rats (recipients). Group 1 (n=12) was preheated 24 h prior to transplantation. In group 2 (n=12) the transplantation was performed without prior heat shock. Group 3 (n=6) was used as a control group with syngeneic hindlimb transplantations between Lewis rats. Postoperatively the appearance of the transplanted hindlimb was evaluated every 12 h. The beginning of rejection was defined when plantar erythema and foot oedema could be observed at the same time. To verify these discrete signs of rejection, the observation was continued for a further 24 h. In this time erythema and oedema spread over the whole transplanted hindlimb. The rat was sacrificed after specimens of skin and muscle had been taken for histological assessment. The rejection in group 1 (with preconditioning heat shock) began after 4.83±0.44 days, in group 2 (without heat shock) already after 3.88±0.53 days. The difference between these groups was significant because of the small standard deviation (Whitney-Mann U test: p<0.01). In our

  12. A Comparative Analysis of Approaches to Heat Transfer Description in a Disperse Inclusions Composite

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2016-01-01

    Full Text Available Composites comprising a matrix with multishaped inclusions are widely used as the engineering structural, building, and functional materials in a variety of instrumentation devices. Among the composites a majority of materials used in engineering are heterogeneous solids. Among these materials there is a large group of composites that have inclusions in the form of fine particles. Those should also include a variety of nanostructured particles with the outlook for their using to provide a capability to enhance mechanical properties of composites.To improve processability of the binder polymer as a component part of the composite are used fine fillers in the form of powder, flakes or fibrous particles. This makes it possible to receive the exotherm during the curing of the binder, to reduce its shrinkage, and improve the mechanical, thermal, electromagnetic and other operational characteristics of the produced composite. However, such fillers available in the binder can cause porosity that impaires the composite properties. The pore emergence is also caused by a long binder shrinkage during its solidification reaching several percent. Particle sizes can vary from a fraction of micrometer to several tens of micrometers. One would expect a similar range of variation of pore sizes.One of the composite characteristics, which is sensitive to inclusions available therein as pores and fine particles, is an effective thermal conductivity that is significant in terms of defining the scope of use for such composites. Calculation formulas for evaluating this factor obtained in the prior art, as a rule, either as a result of experimental data processing in relation to specific materials, or by setting a priori distribution of temperature and heat flow in models of heterogeneous body structure. However, building the mathematical models of a heat transfer process in the composite allows us to define a quantitative effect of the concentration of pore volume and

  13. Studies on corrosion resistance and bio-activity of plasma spray deposited hydroxylapatite (HA) based TiO2 and ZrO2 dispersed composite coatings on titanium alloy (Ti-6Al-4V) and the same after post spray heat treatment

    Science.gov (United States)

    Kumari, Renu; Majumdar, Jyotsna Dutta

    2017-10-01

    In the present study, the effect of plasma spray deposited hydroxylapatite (HA) based TiO2 dispersed (HA + 50 wt.% TiO2), coating and post spray heat treatment to be referred as HA-TiO2 (heat treated at 650 °C for 2 h) and ZrO2 dispersed (HA + 10 wt.% ZrO2), to be referred as HA-ZrO2 coating (heat treated at 750 °C for 2 h) on corrosion resistance and bioactivity of Ti-6Al-4V substrate has been undertaken. There is partial decomposition of HA to tri-calcium-phosphate (Ca3(PO4)2) and formation of CaTiO3 phase in HA-TiO2 coating and CaZrO3 phase in the HA-ZrO2 coating. Corrosion study in Hank's solution shows that there is shifting of corrosion potential (Ecorr) towards active potential (-1.1 V(SCE) for as-sprayed and post spray heat treated HA-TiO2 coating, -1.1 V(SCE) for as-sprayed HA-ZrO2 coating and -1 V(SCE) for HA-ZO2 coating after post spray heat treatment), and deterioration in pitting corrosion (Epit) resistance in as-sprayed coatings and the same after heat treatment (-0.7 V(SCE) for both HA-TiO2 and HA-ZrO2 coating as compared to as received substrate (-0.3 V(SCE)). The corrosion rate was increased for both the coatings with a maximum increase in HA-ZrO2 coating. Bioactivity test shows a higher degree of apatite deposition in as-sprayed coating and the same after heat treatment as compared to as received Ti-6Al-4V though the as-sprayed one showed a superior behavior.

  14. Effect of Homogenizing Heat Treatment of Liquid Aluminum-Copper Alloys on the Structure of Rapidly Crystallized Specimens

    Science.gov (United States)

    Astaf'ev, V. V.; Kurochkin, A. R.; Yablonskikh, T. I.; Brodova, I. G.; Popel', P. S.

    2017-11-01

    Centrifugal casting into a massive slot chill mold was used to prepare two series of specimens of alloys of the Al - Cu system, containing from 10 to 32.2 at.% Cu. The first series was fabricated without a homogenizing heat treatment of the melt, while the second series was fabricated with heating of the melt to 1400°C. Both kinds of specimens were cast at the same temperature in order to provide for the same cooling rate of about 104 K/sec. The structures, phase compositions and microhardnesses of the structural components are compared. It is established that the homogenizing heat treatment changes the kinetics of crystallization and, hence, the proportion of phases in the alloy structure and the copper content in them.

  15. Effectiveness of sanitizers, dry heat, hot water, and gas catalytic infrared heat treatments to inactivate Salmonella on almonds.

    Science.gov (United States)

    Bari, Md Latiful; Nei, Daisuke; Sotome, Itaru; Nishina, Ikuo; Isobe, Seiichi; Kawamoto, Shinnichi

    2009-10-01

    The majority of almond-related foodborne outbreaks have been associated with Salmonella. Therefore, it is necessary to find an effective method to inactivate these organisms on raw almond prior to market distribution. This study was conducted to assess the effectiveness of sanitizers (strong or mild electrolyzed water, ozonated water, and distilled water), dry heat treatment, and hot water treatments followed by catalytic infrared (IR) heat treatment to inactivate Salmonella populations on raw almond. Raw almonds inoculated with four-strain cocktails of Salmonella were treated either by soaking in different chemical sanitizers or with dry heat and/or hot water for various periods of time followed by catalytic IR heat treatment for 70 seconds. The treated seeds were then assessed for the efficacy of the treatment in reducing populations of the pathogens. After inoculation and air-drying, 5.73 +/- 0.12 log colony-forming units (CFU)/g Salmonella were detected in nonselective medium. Sanitizer treatment alone did not show significant reduction in the Salmonella population, but in combination with IR drying it reduced the population to 3.0 log CFU/g. Dry heating at 60 degrees C for 4 days followed by IR drying for 70 seconds reduced the Salmonella population an additional 1.0 log CFU/g. Hot water treatments at 85 degrees C for 40 seconds followed by IR drying for 70 seconds reduced pathogens to an undetectable level by direct plating, but not by enrichment.

  16. Seed set, pollen morphology and pollen surface composition response to heat stress in field pea.

    Science.gov (United States)

    Jiang, Yunfei; Lahlali, Rachid; Karunakaran, Chithra; Kumar, Saroj; Davis, Arthur R; Bueckert, Rosalind A

    2015-11-01

    Pea (Pisum sativum L.) is a major legume crop grown in a semi-arid climate in Western Canada, where heat stress affects pollination, seed set and yield. Seed set and pod growth characteristics, along with in vitro percentage pollen germination, pollen tube growth and pollen surface composition, were measured in two pea cultivars (CDC Golden and CDC Sage) subjected to five maximum temperature regimes ranging from 24 to 36 °C. Heat stress reduced percentage pollen germination, pollen tube length, pod length, seed number per pod, and the seed-ovule ratio. Percentage pollen germination of CDC Sage was greater than CDC Golden at 36 °C. No visible morphological differences in pollen grains or the pollen surface were observed between the heat and control-treated pea. However, pollen wall (intine) thickness increased due to heat stress. Mid-infrared attenuated total reflectance (MIR-ATR) spectra revealed that the chemical composition (lipid, proteins and carbohydrates) of each cultivar's pollen grains responded differently to heat stress. The lipid region of the pollen coat and exine of CDC Sage was more stable compared with CDC Golden at 36 °C. Secondary derivatives of ATR spectra indicated the presence of two lipid types, with different amounts present in pollen grains from each cultivar. © 2015 John Wiley & Sons Ltd.

  17. Characteristics and composition of fouling caused by pig slurry in a tubular heat exchanger--recommended cleaning systems.

    Science.gov (United States)

    Cunault, C; Coquinot, Y; Burton, C H; Picard, S; Pourcher, A M

    2013-03-15

    The structure and composition of the fouling deposits caused by pig slurry heated in a tubular heat exchanger were characterized to understand their formation and thus be able to minimize fouling and define effective routine cleaning methods. Two temperatures (55 °C and 80 °C) were investigated. Two types of fouling were identified: organic/mineral and biofilm. The first only formed at temperatures above 50 °C, often during the heating phase, and was the main problem encountered in treatments at 80 °C. Organic/mineral deposits formed a thin compact sub-layer and a thick porous top layer composed of 67-76% minerals, 9-15% proteins, 8-20% carbohydrates and 0-5% fats. Biofilms formed at temperatures between 25 °C and 70 °C in both the cooling and heating sections of the exchanger. This type of fouling predominated at temperatures below 55 °C. The biofilm covered a thin mineral base layer. Strongly acidic or alkaline washing cycle are recommended to clean Type I deposits, while in-line gas-rumbling is recommended for Type II fouling. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Novel surface treatment for natural fiber composites

    Science.gov (United States)

    Zhang, Wendy; Yuan, Xiaowen

    2017-07-01

    Poly(lactide) (PLA) — flax fibers stereocomplex composites were prepared by casting commercial poly(L-lactide) (PLA) and flax-g-poly(D-lactide) (flax-g-PDLA), where flax-g-PDLA was synthesized via ring-opening polymerization. Successful surface grafting was revealed by Proton Nuclear Magnetic Resonance (1H NMR) spectroscopy, wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) studies. DSC results showed that stereocomplex crystallites formed between the PLA matrix and flax-g-PDLA, resulting in good fiber/PLA interfacial adhesion.

  19. Online and Compositional Learning of Controllers with Application to Floor Heating

    DEFF Research Database (Denmark)

    Larsen, Kim Guldstrand; Mikučionis, Marius; Muniz, Marco

    2016-01-01

    Controller synthesis for stochastic hybrid switched systems, like e.g. a floor heating system in a house, is a complex computational task that cannot be solved by an exhaustive search though all the control options. The state-space to be explored is in general uncountable due to the presence of c...... of the whole state-space. For additional scalability we propose and apply a compositional synthesis approach. Finally, we demonstrate the applicability of the methodology to a concrete floor heating system of a real family house....

  20. Effect of amphiphilic coupling agent on heat flow and dielectric properties of flax – polypropylene composites

    CSIR Research Space (South Africa)

    John, MJ

    2012-03-01

    Full Text Available to the characteristic class of proteins known as prolamines which occur 105 specifically in cereals. The protein products from corn wet milling are corn gluten meal 106 (CGM) and corn gluten feed (CGF) and zein is obtained as a by-product from corn 107 gluten meal... in electronic products. 37 Though natural fibre reinforced composites have advantageous properties, they also 38 have drawbacks in heat dissipation properties. Thermal conductivity, thermal diffusivity 39 and specific heat are the three most important...

  1. Optimization of Composition and Heat Treating of Die Steels for Extended Lifetime

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Quanyou Zhou

    2002-01-30

    An ''average'' die casting die costs fifty thousand dollars. A die used in making die cast aluminum engine blocks can cost well over one million dollars. These costs provide a strong incentive for extension of die life. While vacuum quenched Premium Grade H13 dies have become the most widely used in the United States, tool makers and die casters are constantly searching for new steels and heat treating procedures to extend die life. This project was undertaken to investigate the effects of composition and heat treating on die life and optimize these parameters.

  2. Thin Film Heat Flux Sensor Development for Ceramic Matrix Composite (CMC) Systems

    Science.gov (United States)

    Wrbanek, John D.; Fralick, Gustave C.; Hunter, Gary W.; Zhu, Dongming; Laster, Kimala L.; Gonzalez, Jose M.; Gregory, Otto J.

    2010-01-01

    The NASA Glenn Research Center (GRC) has an on-going effort for developing high temperature thin film sensors for advanced turbine engine components. Stable, high temperature thin film ceramic thermocouples have been demonstrated in the lab, and novel methods of fabricating sensors have been developed. To fabricate thin film heat flux sensors for Ceramic Matrix Composite (CMC) systems, the rough and porous nature of the CMC system posed a significant challenge for patterning the fine features required. The status of the effort to develop thin film heat flux sensors specifically for use on silicon carbide (SiC) CMC systems with these new technologies is described.

  3. Fabrication of TiCx-TiB2/Al Composites for Application as a Heat Sink

    Directory of Open Access Journals (Sweden)

    Shili Shu

    2016-07-01

    Full Text Available Metal matrix composites reinforced with ceramic particles have become the most attractive material in the research and development of new materials for thermal management applications. In this work, 40–60 vol. % TiCx-TiB2/Al composites were successfully fabricated by the method of combustion synthesis and hot press consolidation in an Al-Ti-B4C system. The effect of the TiCx-TiB2 content on the microstructure and compression properties of the composites was investigated. Moreover, the abrasive wear behavior and thermo-physics properties of the TiCx-TiB2/Al composite were studied and compared with the TiCx/Al composite. The compression properties, abrasive wear behavior and thermo-physics properties of the TiCx-TiB2/Al composite are all better than those of the TiCx/Al composite, which confirms that the TiCx-TiB2/Al composite is more appropriate for application as a heat sink.

  4. Fabrication of TiCx-TiB2/Al Composites for Application as a Heat Sink

    Science.gov (United States)

    Shu, Shili; Yang, Hongyu; Tong, Cunzhu; Qiu, Feng

    2016-01-01

    Metal matrix composites reinforced with ceramic particles have become the most attractive material in the research and development of new materials for thermal management applications. In this work, 40–60 vol. % TiCx-TiB2/Al composites were successfully fabricated by the method of combustion synthesis and hot press consolidation in an Al-Ti-B4C system. The effect of the TiCx-TiB2 content on the microstructure and compression properties of the composites was investigated. Moreover, the abrasive wear behavior and thermo-physics properties of the TiCx-TiB2/Al composite were studied and compared with the TiCx/Al composite. The compression properties, abrasive wear behavior and thermo-physics properties of the TiCx-TiB2/Al composite are all better than those of the TiCx/Al composite, which confirms that the TiCx-TiB2/Al composite is more appropriate for application as a heat sink. PMID:28773765

  5. Effects of Heat-treatments on the Mechanical Strength of Coated YSZ: An Experimental Assessment

    DEFF Research Database (Denmark)

    Toftegaard, Helmuth Langmaack; Sørensen, Bent F.; Linderoth, Søren

    2009-01-01

    The mechanical strength of thin, symmetric sandwich specimens consisting of a dense yttria-stabilized zirconia (YSZ) substrate coated with a porous NiO–YSZ layer at both major faces was investigated. Specimens were loaded in uniaxial tension to failure following heat treatments at various...... temperatures. In comparison with the YSZ material, the failure strength of coated specimens was found to increase for heat treatments at 1100°C, but decreased again with further increased heat-treatment temperatures....

  6. Production of Heat Resistant Composite based on Siloxane Elastomer and Multiwall Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Bessonov I.V.

    2016-01-01

    Full Text Available Development of a new generation of composite with unique thermal properties is an important task in the fields of science and technology where material is operated at high temperatures and exposure to a short-wave radiation. Recent studies show that carbon nanomaterials (fullerenes and carbon nanotubes could improve the thermal, radiation and thermal-oxidative stability of the polymer matrix. In this article the development of a new heat resistant composite based on elastomer and carbon nanotubes (CNT was performed and physicochemical properties of final product were evaluated.

  7. Calculation and Designing of Up-to-Date Gas-Flame Plants for Metal Heating and Heat Treatment

    Directory of Open Access Journals (Sweden)

    V. I. Тimoshpolsky

    2008-01-01

    Full Text Available An analysis of development trends in the CIS machine-building industry and current status of the heating and heat treatment furnaces of main machine-building enterprises of the Republic of Belarus as of the 1st quarter of 2008 is given in the paper.The paper presents the most efficient engineering solutions from technological and economic point of view that concern calculation and designing of up-to-date gas-flame plants which are to be applied for modernization of the current heating and heat treatment furnaces of the machine-building enterprises in the Republic of Belarus.A thermo-technical calculation of main indices of the up-to-date gas-flame plant has been carried out in the paper.

  8. Effect of Graphene Coating on the Heat Transfer Performance of a Composite Anti-/Deicing Component

    Directory of Open Access Journals (Sweden)

    Long Chen

    2017-09-01

    Full Text Available The thermal conductivity of a graphene coating for anti-/deicing is rarely studied. This paper presents an improved anti-/deicing efficiency method for composite material anti-/deicing by using the heat-transfer characteristic of a graphene coating. An anti-/deicing experiment was conducted using the centrifugal force generated by a helicopter rotor. Results showed that the graphene coating can accelerate the internal heat transfer of the composite material, thereby improving the anti-icing and deicing efficiency of the helicopter rotor. The spraying process parameters, such as coating thickness and spraying pressure, were also studied. Results showed that reducing coating thickness and increasing spraying pressure are beneficial in preparing a graphene coating with high thermal conductivity. This study provides an experimental reference for the application of a graphene coating in anti-/deicing.

  9. Effects of processing treatments on the nutritive composition and ...

    African Journals Online (AJOL)

    Effects of processing treatments on the nutritive composition and consumer acceptance of some Nigerian edible leafy vegetables. ... HD Mepba, L Eboh, DEB Banigo. Abstract. Leafy vegetables are highly perishable food items and require special processing treatments to prevent post harvest losses. Leafy vegetables to be ...

  10. Surface Oxide Net Charge of a Titanium Alloy; Comparison Between Effects of Treatment With Heat or Radiofrequency Plasma Glow Discharge

    Science.gov (United States)

    MacDonald, Daniel E.; Rapuano, Bruce E.; Schniepp, Hannes C.

    2010-01-01

    In the current study, we have compared the effects of heat and radiofrequency plasma glow discharge (RFGD) treatment of a Ti6Al4V alloy on the physico-chemical properties of the alloy’s surface oxide. Titanium alloy (Ti6Al4V) disks were passivated alone, heated to 600 °C, or RFGD plasma treated in pure oxygen. RFGD treatment did not alter the roughness, topography, elemental composition or thickness of the alloy’s surface oxide layer. In contrast, heat treatment altered oxide topography by creating a pattern of oxide elevations approximately 50–100 nm in diameter. These nanostructures exhibited a three-fold increase in roughness compared to untreated surfaces when RMS roughness was calculated after applying a spatial high-pass filter with a 200 nm cutoff wavelength. Heat treatment also produced a surface enrichment in aluminum and vanadium oxides. Both RFGD and heat treatment produced similar increases in oxide wettability. Atomic force microscopy (AFM) measurements of metal surface oxide net charge signified by a long range force of attraction to or repulsion from a (negatively charged) silicon nitride AFM probe were also obtained for all three experimental groups. Force measurements showed that the RFGD-treated Ti6Al4V samples demonstrated a higher net positive surface charge at pH values below 6 and a higher net negative surface charge at physiological pH (pH values between 7 and 8) compared to control and heat-treated samples These findings suggest that RFGD treatment of metallic implant materials can be used to study the role of negatively charged surface oxide functional groups in protein bioactivity, osteogenic cell behavior and osseointegration independently of oxide topography. PMID:20880672

  11. Microstructural Evolution in Solution Heat Treatment of Gas-Atomized Al Alloy (7075) Powder for Cold Spray

    Science.gov (United States)

    Sabard, A.; de Villiers Lovelock, H. L.; Hussain, T.

    2018-01-01

    Cold gas dynamic spray is being explored as a repair technique for high-value metallic components, given its potential to produce pore and oxide-free deposits of between several micrometers and several millimeters thick with good levels of adhesion and mechanical strength. However, feedstock powders for cold spray experience rapid solidification if manufactured by gas atomization and hence can exhibit non-equilibrium microstructures and localized segregation of alloying elements. Here, we used sealed quartz tube solution heat treatment of a precipitation hardenable 7075 aluminum alloy feedstock to yield a consistent and homogeneous powder phase composition and microstructure prior to cold spraying, aiming for a more controllable heat treatment response of the cold spray deposits. It was shown that the dendritic microstructure and solute segregation in the gas-atomized powders were altered, such that the heat-treated powder exhibits a homogeneous distribution of solute atoms. Micro-indentation testing revealed that the heat-treated powder exhibited a mean hardness decrease of nearly 25% compared to the as-received powder. Deformation of the powder particles was enhanced by heat treatment, resulting in an improved coating with higher thickness ( 300 μm compared to 40 μm for untreated feedstock). Improved particle-substrate bonding was evidenced by formation of jets at the particle boundaries.

  12. Microstructural Evolution in Solution Heat Treatment of Gas-Atomized Al Alloy (7075) Powder for Cold Spray

    Science.gov (United States)

    Sabard, A.; de Villiers Lovelock, H. L.; Hussain, T.

    2017-11-01

    Cold gas dynamic spray is being explored as a repair technique for high-value metallic components, given its potential to produce pore and oxide-free deposits of between several micrometers and several millimeters thick with good levels of adhesion and mechanical strength. However, feedstock powders for cold spray experience rapid solidification if manufactured by gas atomization and hence can exhibit non-equilibrium microstructures and localized segregation of alloying elements. Here, we used sealed quartz tube solution heat treatment of a precipitation hardenable 7075 aluminum alloy feedstock to yield a consistent and homogeneous powder phase composition and microstructure prior to cold spraying, aiming for a more controllable heat treatment response of the cold spray deposits. It was shown that the dendritic microstructure and solute segregation in the gas-atomized powders were altered, such that the heat-treated powder exhibits a homogeneous distribution of solute atoms. Micro-indentation testing revealed that the heat-treated powder exhibited a mean hardness decrease of nearly 25% compared to the as-received powder. Deformation of the powder particles was enhanced by heat treatment, resulting in an improved coating with higher thickness ( 300 μm compared to 40 μm for untreated feedstock). Improved particle-substrate bonding was evidenced by formation of jets at the particle boundaries.

  13. Theory and practice for the manufacture of a composite thermal heat shield for a space ship

    Science.gov (United States)

    Tarasov, V. A.; Komkov, M. A.; Romanenkov, V. A.; Alyamovsky, A. I.; Kopyl, N. I.; Boyarskaya, R. V.

    2016-10-01

    The technological processes were explored for the manufacture in an autoclave of a space ship heat shield. A mathematical model was created for the determination of the duration of the impregnation of the binder for the composite material. The change in the Nitrogen content is dependent on the time in the autoclave. This dependence relates to the use of the minimum amount of electricity to reduce the expense of the process in practice.

  14. Nano-engineered Multiwall Carbon Nanotube-copper Composite Thermal Interface Material for Efficient Heat Conduction

    Science.gov (United States)

    Ngo, Quoc; Cruden, Brett A.; Cassell, Alan M.; Sims, Gerard; Li, Jun; Meyyappa, M.; Yang, Cary Y.

    2005-01-01

    Efforts in integrated circuit (IC) packaging technologies have recently been focused on management of increasing heat density associated with high frequency and high density circuit designs. While current flip-chip package designs can accommodate relatively high amounts of heat density, new materials need to be developed to manage thermal effects of next-generation integrated circuits. Multiwall carbon nanotubes (MWNT) have been shown to significantly enhance thermal conduction in the axial direction and thus can be considered to be a candidate for future thermal interface materials by facilitating efficient thermal transport. This work focuses on fabrication and characterization of a robust MWNT-copper composite material as an element in IC package designs. We show that using vertically aligned MWNT arrays reduces interfacial thermal resistance by increasing conduction surface area, and furthermore, the embedded copper acts as a lateral heat spreader to efficiently disperse heat, a necessary function for packaging materials. In addition, we demonstrate reusability of the material, and the absence of residue on the contacting material, both novel features of the MWNT-copper composite that are not found in most state-of-the-art thermal interface materials. Electrochemical methods such as metal deposition and etch are discussed for the creation of the MWNT-Cu composite, detailing issues and observations with using such methods. We show that precise engineering of the composite surface affects the ability of this material to act as an efficient thermal interface material. A thermal contact resistance measurement has been designed to obtain a value of thermal contact resistance for a variety of different thermal contact materials.

  15. Raman scattering in Si/SiGe nanostructures: Revealing chemical composition, strain, intermixing, and heat dissipation

    Energy Technology Data Exchange (ETDEWEB)

    Mala, S. A.; Tsybeskov, L., E-mail: tsybesko@njit.edu [Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102 (United States); Lockwood, D. J.; Wu, X.; Baribeau, J.-M. [National Research Council, Ottawa, Ontario K1A 0R6 (Canada)

    2014-07-07

    We present a quantitative analysis of Raman scattering in various Si/Si{sub 1-x}Ge{sub x} multilayered nanostructures with well-defined Ge composition (x) and layer thicknesses. Using Raman and transmission electron microscopy data, we discuss and model Si/SiGe intermixing and strain. By analyzing Stokes and anti-Stokes Raman signals, we calculate temperature and discuss heat dissipation in the samples under intense laser illumination.

  16. Enhanced Thermo-Optical Switching of Paraffin-Wax Composite Spots under Laser Heating.

    Science.gov (United States)

    Said, Asmaa; Salah, Abeer; Fattah, Gamal Abdel

    2017-05-12

    Thermo-optical switches are of particular significance in communications networks where increasingly high switching speeds are required. Phase change materials (PCMs), in particular those based on paraffin wax, provide wealth of exciting applications with unusual thermally-induced switching properties, only limited by paraffin's rather low thermal conductivity. In this paper, the use of different carbon fillers as thermal conductivity enhancers for paraffin has been investigated, and a novel structure based on spot of paraffin wax as a thermo-optic switch is presented. Thermo-optical switching parameters are enhanced with the addition of graphite and graphene, due to the extreme thermal conductivity of the carbon fillers. Differential Scanning Calorimetry (DSC) and Scanning electron microscope (SEM) are performed on paraffin wax composites, and specific heat capacities are calculated based on DSC measurements. Thermo-optical switching based on transmission is measured as a function of the host concentration under conventional electric heating and laser heating of paraffin-carbon fillers composites. Further enhancements in thermo-optical switching parameters are studied under Nd:YAG laser heating. This novel structure can be used in future networks with huge bandwidth requirements and electric noise free remote aerial laser switching applications.

  17. Effect of Austenitizing Heat Treatment on the Microstructure and Hardness of Martensitic Stainless Steel AISI 420

    Science.gov (United States)

    Barlow, L. D.; Du Toit, M.

    2012-07-01

    The effect of austenitizing on the microstructure and hardness of two martensitic stainless steels was examined with the aim of supplying heat-treatment guidelines to the user that will ensure a martensitic structure with minimal retained austenite, evenly dispersed carbides and a hardness of between 610 and 740 HV (Vickers hardness) after quenching and tempering. The steels examined during the course of this examination conform in composition to medium-carbon AISI 420 martensitic stainless steel, except for the addition of 0.13% vanadium and 0.62% molybdenum to one of the alloys. Steel samples were austenitized at temperatures between 1000 and 1200 °C, followed by oil quenching. The as-quenched microstructures were found to range from almost fully martensitic structures to martensite with up to 35% retained austenite after quenching, with varying amounts of carbides. Optical and scanning electron microscopy was used to characterize the microstructures, and X-ray diffraction was employed to identify the carbide present in the as-quenched structures and to quantify the retained austenite contents. Hardness tests were performed to determine the effect of heat treatment on mechanical properties. As-quenched hardness values ranged from 700 to 270 HV, depending on the amount of retained austenite. Thermodynamic predictions (using the CALPHAD™ model) were employed to explain these microstructures based on the solubility of the carbide particles at various austenitizing temperatures.

  18. Synthesis of hydroxyapatite from eggshell powders through ball milling and heat treatment

    Directory of Open Access Journals (Sweden)

    Shih-Ching Wu

    2016-03-01

    Full Text Available Every day, several million tons of eggshells are being generated as bio-waste across the world. This study demonstrates the synthesis of HA powder using dicalcium phosphate dehydrate (CaHPO4·2H2O, DCPD and eggshell powders via ball milling and subsequent heat treatment. The formation of HA phase can be initiated by sintering the 1 h milled sample at 1000 °C for 1 h, while pure HA phase can be obtained upon sintering the 10 h milled sample. Additionally, the final products composed of biphasic calcium phosphate (HA + β-TCP crystals can easily be prepared by ball milling for 5 h followed by heat treatment at 1000 °C for 1 h. The carbonate peaks observed in the FTIR analysis of the as-prepared HA closely matched those of A- and B-type carbonates, which is typical of the biological apatite. The elemental composition of the as-synthesized HA showed the presence of Ca, P, Mg, and Sr.

  19. Enhanced boiling performance of a nanoporous copper surface by electrodeposition and heat treatment

    Science.gov (United States)

    Gao, Jiao; Lu, Long-Sheng; Sun, Jia-Wei; Liu, Xiao-Kang; Tang, Biao

    2017-03-01

    A nanoporous structure was fabricated on the surface of a copper block by electrodeposition and heat treatment compound technology. The influence of the heat treatment parameters on the binding force of a structure was analyzed, and a platform was set up to test the pool boiling heat transfer performance. By observing the SEM morphology, the effect of electrodeposition parameters on the formation of nanoporous structure was determined, and the heat transfer coefficient and wall superheat between different surfaces were compared. At the same time, by means of visualization, the bubble behavior of a smooth surface and a nanoporous surface under different heat fluxes was studied. The results show that the surface structure of nanoporous copper prepared by electrodeposition and heat treatment can improve the bonding strength by 77 %, decrease the wall superheat by 45 %, and increase the heat transfer coefficient by 80 %.

  20. Untargeted analysis to monitor metabolic changes of garlic along heat treatment by LC-QTOF MS/MS.

    Science.gov (United States)

    Molina-Calle, María; Sánchez de Medina, Verónica; Calderón-Santiago, Mónica; Priego-Capote, Feliciano; Luque de Castro, María D

    2017-09-01

    Black garlic is increasing its popularity in cuisine around the world; however, scant information exists on the composition of this processed product. In this study, polar compounds in fresh garlic and in samples taken at different times during the heat treatment process to obtain black garlic have been characterized by liquid chromatography coupled to tandem mass spectrometry in high resolution mode. Ninety-five compounds (mainly amino acids and metabolites, organosulfur compounds, and saccharides and derivatives) were tentatively identified in all the analysed samples and classified as a function of the family they belong to. Statistical analysis of the results allowed establishing that the major changes in garlic occur during the first days of treatment, and they mainly affect to the three representative families. The main pathways involved in the synthesis of the compounds affected by heat treatment, and their evolution during the process were studied. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Pre-heating of high-viscosity bulk-fill resin composites: Effects on shrinkage force and monomer conversion

    OpenAIRE

    Tobias T. Tauböck; Tarle, Zrinka; Marovic, Danijela; Attin, Thomas

    2015-01-01

    OBJECTIVES To investigate the influence of pre-heating of high-viscosity bulk-fill composite materials on their degree of conversion and shrinkage force formation. METHODS Four bulk-fill composite materials (Tetric EvoCeram Bulk Fill-TECBF, x-tra fil-XF, QuixFil-QF, SonicFill-SF) and one conventional nano-hybrid resin composite (Tetric EvoCeram-TEC) were used. The test materials were either kept at room temperature or pre-heated to 68°C by means of a commercial heating device, before being...

  2. Produktivitas Benih Cabai Rawit Setelah Diperlakukan Dry Heat Treatment dan Penyimpanan

    Directory of Open Access Journals (Sweden)

    I GUSTI NGURAH RAKA

    2015-09-01

    Full Text Available Productivity of Pepper Seeds Which are Treated Dry Heat Treatment and Storage Pepper plants (Capsicum frutescens L. is one type of horticultural crops which is very high usage levels therefor, it is necessary to increase productivity dramatically. One effort to fulfil the need is preparing healthy seed with long shelf life . This study aims to determine the growth and yield of pepper plants whose seed was treated with dry heat treatment and storage. The experiment was conducted in Br . Marga Tengah, Kerta Village, Payangan District, Gianyar Regency, since May to October 2013. This study used a randomized block design (RBD with two factors and four replications. The first factor is treated seeds by dry heat treatment at two levels i.e. given dry heat treatment at 70OC for 72 hours (D1 and without dry heat treatment (D0. The second factor is the storage of seeds with three levels, namely: non-stored seeds (T0, seed stored 2 months (T2 and the seeds stored for 4 months (T4. The results showed that there was no interaction between treatment with dry heat treatment and seed storage treatment of all variables of growth and yield of pepper plants. Dry heat treatment resulted the better growth and yield compared to non dry heat treatment. An increase in the number of fruit harvest as much as 33,43% and increased the weight of the fruit harvest per hectare as much as 33,79% on dry heat treatment compared with no dry heat treatment. Treatment of seed storage until the shelf life of 4 months did not affect the growth and yield of pepper plants.

  3. A combination of heat treatment and Pichia guilliermondii prevents cherry tomato spoilage by fungi.

    Science.gov (United States)

    Zhao, Yan; Tu, Kang; Tu, Sicong; Liu, Ming; Su, Jing; Hou, Yue-Peng

    2010-01-31

    This study investigated the effectiveness of heat treatment and Pichia guilliermondii, either alone or in combination, to combat postharvest fungal spoilage in cherry tomato fruit. In vitro experiments demonstrated that heat treatment at 38 degrees C significantly inhibited mycelial growth of three different pathogens (Botrytis cinerea, Alternaria alternata and Rhizopus stolonifer Ehrenb). In vivo experiments unveiled that either heat treatment or P. guilliermondii reduced decay caused by these pathogens. Furthermore, a combination of heat treatment followed by the application of P. guilliermondii (H+P) provided the best efficacy in prevention of cherry tomato from fungal spoilage. Following, H+P treatment, electronic nose detected a reduction of volatility in cherry tomato fruit odor, an indicator of preserving fruit's freshness. Scanning electron microscopy unveiled that heat treatment at 38 degrees C for 24h inhibited hyphae growth and spore germination of R. stolonifer Ehrenb while P. guilliermondii multiplied rapidly on fruit wounds, and its cells had a strong capability of adhesion to the hyphae of R. stolonifer Ehrenb. However, heat treatment also seriously injured P. guilliermondii, therefore P. guilliermondii should be applied after heat treatment. A combination of heat treatment and P. guilliermondii is one of the most effective techniques at controlling postharvest fungal spoilage in cherry tomato fruit. Copyright 2009 Elsevier B.V. All rights reserved.

  4. 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.

  5. Effect of heat treatment on transformation temperatures and bending properties of nickel-titanium endodontic instruments.

    Science.gov (United States)

    Yahata, Y; Yoneyama, T; Hayashi, Y; Ebihara, A; Doi, H; Hanawa, T; Suda, H

    2009-07-01

    To investigate the effect of heat treatment on the bending properties of nickel-titanium endodontic instruments in relation to their transformation behaviour. Nickel-titanium super-elastic alloy wire (1.00 mm Ø) was processed into a conical shape with a 0.30 mm diameter tip and 0.06 taper. The heat treatment temperature was set at 440 or 500 degrees C for a period of 10 or 30 min. Nonheat-treated specimens were used as controls. The phase transformation behaviour was examined using differential scanning calorimetry. A cantilever-bending test was used to evaluate the bending properties of the specimens. Data were analyzed by ANOVA and the Tukey-Kramer test (P = 0.05). The transformation temperature was higher for each heat treatment condition compared with the control. Two clear thermal peaks were observed for the heat treatment at 440 degrees C. The specimen heated at 440 degrees C for 30 min exhibited the highest temperatures for M(s) and A(f), with subsequently lower temperatures observed for specimens heated at 440 degrees C for 10 min, 500 degrees C for 30 min, 500 degrees C for 10 min, and control specimens. The sample heated at 440 degrees C for 30 min had the lowest bending load values (P treatment time was less than that of heat treatment temperature. Change in the transformation behaviour by heat treatment may be effective in increasing the flexibility of nickel-titanium endodontic instruments.

  6. Influence of Heat Treatment on the Conductivity of Nickel-Based Superalloys

    Directory of Open Access Journals (Sweden)

    Nagarajan Balasubramanian

    2015-01-01

    Full Text Available Non-destructive measurement of residual stress at the subsurface of nickel-based alloys using eddy current method has been limited by its sensitivity to its microstructure, especially to the precipitates. This paper investigates the effect of heat treatment on the electrical conductivity of RR1000, a nickel-based superalloy with a large fraction of γ’ precipitates. Different heat treatment conditions, ranging from solution heat treatment to precipitation hardening with different aging times and temperatures, are used to achieve varying initial microstructures. Hardness of the samples is measured first to quantify the heat treated samples followed by the measurement of electrical conductivity using the conductivity probes of frequencies between 1 MHz and 5 MHz. The relationship between the hardness and conductivity of the heat treated samples is then correlated further. The results highlight the significant influence of heat treatment on the sample hardness and the electrical conductivity of RR1000.

  7. Calibration of Discrete Element Heat Transfer Parameters by Central Composite Design

    Science.gov (United States)

    Deng, Zongquan; Cui, Jinsheng; Hou, Xuyan; Jiang, Shengyuan

    2017-03-01

    The efficiency and precision of parameter calibration in discrete element method (DEM) are not satisfactory, and parameter calibration for granular heat transfer is rarely involved. Accordingly, parameter calibration for granular heat transfer with the DEM is studied. The heat transfer in granular assemblies is simulated with DEM, and the effective thermal conductivity (ETC) of these granular assemblies is measured with the transient method in simulations. The measurement testbed is designed to test the ETC of the granular assemblies under normal pressure and a vacuum based on the steady method. Central composite design (CCD) is used to simulate the impact of the DEM parameters on the ETC of granular assemblies, and the heat transfer parameters are calibrated and compared with experimental data. The results show that, within the scope of the considered parameters, the ETC of the granular assemblies increases with an increasing particle thermal conductivity and decreases with an increasing particle shear modulus and particle diameter. The particle thermal conductivity has the greatest impact on the ETC of granular assemblies followed by the particle shear modulus and then the particle diameter. The calibration results show good agreement with the experimental results. The error is less than 4%, which is within a reasonable range for the scope of the CCD parameters. The proposed research provides high efficiency and high accuracy parameter calibration for granular heat transfer in DEM.

  8. Orthodontic treatment finishing with minimally invasive resin composite veneers.

    OpenAIRE

    Maenosono, Rafael Massunari; Department of Operative Dentistry, Endodontics and Dental Materials – Bauru School of Dentistry – University of São Paulo – Bauru – São Paulo – Brazil.; Ramos, Carla Muller; Department of Operative Dentistry, Endodontics and Dental Materials – Bauru School of Dentistry – University of São Paulo – Bauru – São Paulo – Brazil.; Brianezzi, Letícia Ferreira de Freitas; Department of Operative Dentistry, Endodontics and Dental Materials – Bauru School of Dentistry – University of São Paulo – Bauru – São Paulo – Brazil.; Oda, Denise Ferracioli; Department of Operative Dentistry, Endodontics and Dental Materials – Bauru School of Dentistry – University of São Paulo – Bauru – São Paulo – Brazil.; Mondelli, Rafael Francisco Lia; Department of Operative Dentistry, Endodontics and Dental Materials – Bauru School of Dentistry – University of São Paulo – Bauru – São Paulo – Brazil.; Ishikiriama, Sérgio Kiyoshi; Department of Operative Dentistry, Endodontics and Dental Materials – Bauru School of Dentistry – University of São Paulo – Bauru – São Paulo – Brazil.

    2015-01-01

    Anatomic alterations caused by incisal guide wear, even being small, cause the aspect of an aged smile. The objective of this clinical case is to report a highly conservative esthetical treatment, performed through the association of in-office bleaching and resin composite veneers. In-office bleaching was performed with 35% hydrogen peroxide, and in the following week minimal invasive resin composite veneers were implemented on upper incisors and canines. In the next appointment, finishing an...

  9. Seedbed treatment with direct heat from burning stubble and its ...

    African Journals Online (AJOL)

    off was 0, 0.65 and 55.88 per cent, respectively, on the heated, formalin-treated and untreated beds. Tomato seedling growth (seedling height, fresh and dry weights) was significantly greater on the heated bed than on the unheated bed. Higher ...

  10. Simple and Rapid Synthesis of Magnetite/Hydroxyapatite Composites for Hyperthermia Treatments via a Mechanochemical Route

    Science.gov (United States)

    Iwasaki, Tomohiro; Nakatsuka, Ryo; Murase, Kenya; Takata, Hiroshige; Nakamura, Hideya; Watano, Satoru

    2013-01-01

    This paper presents a simple method for the rapid synthesis of magnetite/hydroxyapatite composite particles. In this method, superparamagnetic magnetite nanoparticles are first synthesized by coprecipitation using ferrous chloride and ferric chloride. Immediately following the synthesis, carbonate-substituted (B-type) hydroxyapatite particles are mechanochemically synthesized by wet milling dicalcium phosphate dihydrate and calcium carbonate in a dispersed suspension of magnetite nanoparticles, during which the magnetite nanoparticles are incorporated into the hydroxyapatite matrix. We observed that the resultant magnetite/hydroxyapatite composites possessed a homogeneous dispersion of magnetite nanoparticles, characterized by an absence of large aggregates. When this material was subjected to an alternating magnetic field, the heat generated increased with increasing magnetite concentration. For a magnetite concentration of 30 mass%, a temperature increase greater than 20 K was achieved in less than 50 s. These results suggest that our composites exhibit good hyperthermia properties and are promising candidates for hyperthermia treatments. PMID:23629669

  11. Effect of post-polymerization heat treatments on the cytotoxicity of two denture base acrylic resins.

    Science.gov (United States)

    Jorge, Janaina Habib; Giampaolo, Eunice Teresinha; Vergani, Carlos Eduardo; Machado, Ana Lúcia; Pavarina, Ana Cláudia; Carlos, Iracilda Zeppone

    2006-06-01

    Most denture base acrylic resins have polymethylmethacrylate in their composition. Several authors have discussed the polymerization process involved in converting monomer into polymer because adequate polymerization is a crucial factor in optimizing the physical properties and biocompatibility of denture base acrylic resins. To ensure the safety of these materials, in vitro cytotoxicity assays have been developed as preliminary screening tests to evaluate material biocompatibility. (3)H-thymidine incorporation test, which measures the number of cells synthesizing DNA, is one of the biological assays suggested for cytotoxicity testing. The purpose of this study was to investigate, using (3)H-thymidine incorporation test, the effect of microwave and water-bath post-polymerization heat treatments on the cytotoxicity of two denture base acrylic resins. Nine disc-shaped specimens (10 x 1 mm) of each denture base resin (Lucitone 550 and QC 20) were prepared according to the manufacturers' recommendations and stored in distilled water at 37 degrees C for 48 h. The specimens were assigned to 3 groups: 1) post-polymerization in a microwave oven for 3 min at 500 W; 2) post-polymerization in water-bath at 55 degrees C for 60 min; and 3) without post-polymerization. For preparation of eluates, 3 discs were placed into a sterile glass vial with 9 mL of Eagle's medium and incubated at 37 degrees C for 24 h. The cytotoxic effect of the eluates was evaluated by (3)H-thymidine incorporation. The results showed that the components leached from the resins were cytotoxic to L929 cells, except for the specimens heat treated in water bath (pmicrowave post-polymerization heat treatment.

  12. Thermochemical Characterizations of Novel Vermiculite-LiCl Composite Sorbents for Low-Temperature Heat Storage

    Directory of Open Access Journals (Sweden)

    Yannan Zhang

    2016-10-01

    Full Text Available To store low-temperature heat below 100 °C, novel composite sorbents were developed by impregnating LiCl into expanded vermiculite (EVM in this study. Five kinds of composite sorbents were prepared using different salt concentrations, and the optimal sorbent for application was selected by comparing both the sorption characteristics and energy storage density. Textural properties of composite sorbents were obtained by extreme-resolution field emission scanning electron microscopy (ER-SEM and an automatic mercury porosimeter. After excluding two composite sorbents which would possibly exhibit solution leakage in practical thermal energy storage (TES system, thermochemical characterizations were implemented through simulative sorption experiments at 30 °C and 60% RH. Analyses of thermogravimetric analysis/differential scanning calorimetry (TGA/DSC curves indicate that water uptake of EVM/LiCl composite sorbents is divided into three parts: physical adsorption of EVM, chemical adsorption of LiCl crystal, and liquid–gas absorption of LiCl solution. Energy storage potential was evaluated by theoretical calculation based on TGA/DSC curves. Overall, EVMLiCl20 was selected as the optimal composite sorbent with water uptake of 1.41 g/g, mass energy storage density of 1.21 kWh/kg, and volume energy storage density of 171.61 kWh/m3.

  13. A fractal image analysis methodology for heat damage inspection in carbon fiber reinforced composites

    Science.gov (United States)

    Haridas, Aswin; Crivoi, Alexandru; Prabhathan, P.; Chan, Kelvin; Murukeshan, V. M.

    2017-06-01

    The use of carbon fiber-reinforced polymer (CFRP) composite materials in the aerospace industry have far improved the load carrying properties and the design flexibility of aircraft structures. A high strength to weight ratio, low thermal conductivity, and a low thermal expansion coefficient gives it an edge for applications demanding stringent loading conditions. Specifically, this paper focuses on the behavior of CFRP composites under stringent thermal loads. The properties of composites are largely affected by external thermal loads, especially when the loads are beyond the glass temperature, Tg, of the composite. Beyond this, the composites are subject to prominent changes in mechanical and thermal properties which may further lead to material decomposition. Furthermore, thermal damage formation being chaotic, a strict dimension cannot be associated with the formed damage. In this context, this paper focuses on comparing multiple speckle image analysis algorithms to effectively characterize the formed thermal damages on the CFRP specimen. This would provide us with a fast method for quantifying the extent of heat damage in carbon composites, thus reducing the required time for inspection. The image analysis methods used for the comparison include fractal dimensional analysis of the formed speckle pattern and analysis of number and size of various connecting elements in the binary image.

  14. Industrial heat treatment of R-HPDC A356 automotive brake callipers

    CSIR Research Space (South Africa)

    Chauke, L

    2012-10-01

    Full Text Available Heat treatment of rheo-high pressure die cast (R-HPDC) A356 brake callipers has produced good mechanical properties on the laboratory scale. An industrial heat treatment is required to evaluate the applicability and conformance of the R-HPDC A356...

  15. 49 CFR 179.201-5 - Postweld heat treatment and corrosion resistance.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Postweld heat treatment and corrosion resistance....201-5 Postweld heat treatment and corrosion resistance. (a) Tanks and attachments welded directly... tested to demonstrate that they possess the corrosion resistance specified in § 179.200-7(d), Footnote 2...

  16. Industrial heat treatment of R-HPDC A356 automotive brake callipers [Conference paper

    CSIR Research Space (South Africa)

    Chauke, L

    2012-10-01

    Full Text Available Heat treatment of rheo-high pressure die cast (R-HPDC) A356 brake callipers has produced good mechanical properties on the laboratory scale. An industrial heat treatment is required to evaluate the applicability and conformance of the R-HPDC A356...

  17. Compositions and Methods for the Treatment of Pierce's Disease

    Science.gov (United States)

    Gupta, Goutam

    2008-10-07

    Chimeric anti-microbial proteins, compositions, and methods for the therapeutic and prophylactic treatment of plant diseases caused by the bacterial pathogen Xylella fastidiosa are provided. The anti-microbial proteins of the invention generally comprise a surface recognition domain polypeptide, capable of binding to a bacterial membrane component, fused to a bacterial lysis domain polypeptide, capable of affecting lysis or rupture of the bacterial membrane, typically via a fused polypeptide linker. In particular, methods and compositions for the treatment or prevention of Pierce's disease of grapevines are provided. Methods for the generation of transgenic Vitus vinefera plants expressing xylem-secreted anti-microbial chimeras are also provided.

  18. Study of heat treatment parameters for large-scale hydraulic steel gate track

    Directory of Open Access Journals (Sweden)

    Ping-zhou Cao

    2013-10-01

    Full Text Available In order to enhance external hardness and strength, a large-scale hydraulic gate track should go through heat treatment. The current design method of hydraulic gate wheels and tracks is based on Hertz contact linear elastic theory, and does not take into account the changes in mechanical properties of materials caused by heat treatment. In this study, the heat treatment parameters were designed and analyzed according to the bearing mechanisms of the wheel and track. The quenching process of the track was simulated by the ANSYS program, and the temperature variation, residual stress, and deformation were obtained and analyzed. The metallurgical structure field after heat treatment was predicted by the method based on time-temperature-transformation (TTT curves. The results show that the analysis method and designed track heat treatment process are feasible, and can provide a reference for practical projects.

  19. Effect of heat treatment on mechanical dissipation in Ta2O5 coatings

    Science.gov (United States)

    Martin, I. W.; Bassiri, R.; Nawrodt, R.; Fejer, M. M.; Gretarsson, A.; Gustafson, E.; Harry, G.; Hough, J.; MacLaren, I.; Penn, S.; Reid, S.; Route, R.; Rowan, S.; Schwarz, C.; Seidel, P.; Scott, J.; Woodcraft, A. L.

    2010-11-01

    Thermal noise arising from mechanical dissipation in dielectric reflective coatings is expected to critically limit the sensitivity of precision measurement systems such as high-resolution optical spectroscopy, optical frequency standards and future generations of interferometric gravitational wave detectors. We present measurements of the effect of post-deposition heat treatment on the temperature dependence of the mechanical dissipation in ion-beam sputtered tantalum pentoxide between 11 K and 300 K. We find that the temperature dependence of the dissipation is strongly dependent on the temperature at which the heat treatment was carried out, and we have identified three dissipation peaks occurring at different heat treatment temperatures. At temperatures below 200 K, the magnitude of the loss was found to increase with higher heat treatment temperatures, indicating that heat treatment is a significant factor in determining the level of coating thermal noise.

  20. An electrical-heating and self-sensing shape memory polymer composite incorporated with carbon fiber felt

    Science.gov (United States)

    Gong, Xiaobo; Liu, Liwu; Liu, Yanju; Leng, Jinsong

    2016-03-01

    Shape memory polymers (SMPs) have the ability to adjust their stiffness, lock a temporary shape, and recover the permanent shape upon imposing an appropriate stimulus. They have found their way into the field of morphing structures. The electrically Joule resistive heating of the conductive composite can be a desirable stimulus to activate the shape memory effect of SMPs without external heating equipment. Electro-induced SMP composites incorporated with carbon fiber felt (CFF) were explored in this work. The CFF is an excellent conductive filler which can easily spread throughout the composite. It has a huge advantage in terms of low cost, simple manufacturing process, and uniform and tunable temperature distribution while heating. A continuous and compact conductive network made of carbon fibers and the overlap joints among them was observed from the microscopy images, and this network contributes to the high conductive properties of the CFF/SMP composites. The CFF/SMP composites can be electrical-heated rapidly and uniformly, and its’ shape recovery effect can be actuated by the electrical resistance Joule heating of the CFF without an external heater. The CFF/SMP composite get higher modulus and higher strength than the pure SMP without losing any strain recovery property. The high dependence of temperature and strain on the electrical resistance also make the composite a good self-sensing material. In general, the CFF/SMP composite shows great prospects as a potential material for the future morphing structures.

  1. A New Adsorbent Composite Material Based on Metal Fiber Technology and Its Application in Adsorption Heat Exchangers

    Directory of Open Access Journals (Sweden)

    Ursula Wittstadt

    2015-08-01

    Full Text Available In order to achieve process intensification for adsorption chillers and heat pumps, a new composite material was developed based on sintered aluminum fibers from a melt-extraction process and a dense layer of silico-aluminophosphate (SAPO-34 on the fiber surfaces. The SAPO-34 layer was obtained through a partial support transformation (PST process. Preparation of a composite sample is described and its characteristic pore size distribution and heat conductivity are presented. Water adsorption data obtained under conditions of a large pressure jump are given. In the next step, preparation of the composite was scaled up to larger samples which were fixed on a small adsorption heat exchanger. Adsorption measurements on this heat exchanger element that confirm the achieved process intensification are presented. The specific cooling power for the adsorption step per volume of composite is found to exceed 500 kW/m3 under specified conditions.

  2. Sustainable, heat-resistant and flame-retardant cellulose-based composite separator for high-performance lithium ion battery

    National Research Council Canada - National Science Library

    Zhang, Jianjun; Yue, Liping; Kong, Qingshan; Liu, Zhihong; Zhou, Xinhong; Zhang, Chuanjian; Xu, Quan; Zhang, Bo; Ding, Guoliang; Qin, Bingsheng; Duan, Yulong; Wang, Qingfu; Yao, Jianhua; Cui, Guanglei; Chen, Liquan

    2014-01-01

    A sustainable, heat-resistant and flame-retardant cellulose-based composite nonwoven has been successfully fabricated and explored its potential application for promising separator of high-performance...

  3. Monovarietal extra virgin olive oils. Correlation between thermal properties and chemical composition: heating thermograms.

    Science.gov (United States)

    Chiavaro, Emma; Vittadini, Elena; Rodriguez-Estrada, Maria Teresa; Cerretani, Lorenzo; Bendini, Alessandra

    2008-01-23

    Extra virgin olive oils from drupes of three Sicilian varieties (Biancolilla, Cerasuola, and Nocellara del Belice) collected at three different harvesting periods were analyzed upon heating by means of DSC, and thermal properties were related to the chemical composition of the samples. All thermograms exhibited multiple transitions with a minor exothermic peak, followed by a major endothermic event. Cerasuola samples showed higher overall enthalpy and narrower range of transition at all harvesting periods, as compared to the other oils. A more ordered crystal structure originating from a more uniform chemical composition, with higher triolein content, in Cerasuola may be hypothesized. At different harvesting periods, thermal transitions started at lower temperatures and developed over a narrower range in all cultivars, probably due to the insertion of molecules derived from triacylglycerol lysis (diacylglycerols and free fatty acids) and lipid oxidation products into the triacylglycerol crystal lattice. All heating thermograms were deconvoluted into one exothermic and five endothermic constituent peaks, and the effect of chemical components on thermal properties of the peaks was evaluated. DSC application upon heating appears to be very promising in discriminating among oil samples from olives of different cultivars and/or harvesting periods.

  4. Review of thermo-physical properties, wetting and heat transfer characteristics of nanofluids and their applicability in industrial quench heat treatment

    Directory of Open Access Journals (Sweden)

    Ramesh Gopalan

    2011-01-01

    Full Text Available Abstract The success of quenching process during industrial heat treatment mainly depends on the heat transfer characteristics of the quenching medium. In the case of quenching, the scope for redesigning the system or operational parameters for enhancing the heat transfer is very much limited and the emphasis should be on designing quench media with enhanced heat transfer characteristics. Recent studies on nanofluids have shown that these fluids offer improved wetting and heat transfer characteristics. Further water-based nanofluids are environment friendly as compared to mineral oil quench media. These potential advantages have led to the development of nanofluid-based quench media for heat treatment practices. In this article, thermo-physical properties, wetting and boiling heat transfer characteristics of nanofluids are reviewed and discussed. The unique thermal and heat transfer characteristics of nanofluids would be extremely useful for exploiting them as quench media for industrial heat treatment.

  5. Interactions between goethite particles subjected to heat treatment

    DEFF Research Database (Denmark)

    Madsen, Daniel Esmarch; Hansen, Mikkel Fougt; Koch, C.B.

    2008-01-01

    We have studied the effect of heating on the magnetic properties of particles of nanocrystalline goethite by use of Mossbauer spectroscopy. Heating at 150 degrees C for 24 h leads to a change in the quadrupole shift in the low-temperature spectra, indicating a rotation of the sublattice...... magnetization directions. Fitting of quantiles, derived from the asymmetrically broadened spectra between 80 and 300 K, to the superferromagnetism model indicates that this change is due to a stronger magnetic coupling between the particles....

  6. Studying heat treatment impact on heat resisting properties of Cr-Ni – A. E. system alloy

    Directory of Open Access Journals (Sweden)

    Sv. Kvon

    2017-01-01

    Full Text Available The article presents the results the impact of heat treatment on iron-n ickel alloys with adding Mo, Nb, Ti and Al, at this the content of chrome was increased in comparison with the classical structure to 40-45%.

  7. Industrial application of different heat treatments and cream fat contents for improving the spreadability of butter

    DEFF Research Database (Denmark)

    Tondhoosh, Arash; Nayebzadeh, Kooshan; Mohammadifar, Mohammad Amin

    2016-01-01

    hardening of texture especially in winter. Methods: Firstly, Pasteurized cream with different fat contents (40 & 45% fat) was passed through heat treatments, and then it was injected to a continuous churn. Textural and melting behavior and fatty acid composition of butter were analyzed. Results: Increasing...... the fat content of cream (from 40 to 45 %) and holding time (from 3h to 5h) in mid-temperature (18 °C) and reducing the churning temperature (from 12 °C to 10 °C), resulted in soft butter texture and improved butter spreadability. Loss Tangent (tan δ) was increased from 0.11 to 0.74 (T=15 °C;f=1Hz......). The melting temperature of butter was decreased from 36°C to 32°C and total trans fatty acid content was decreased from 3.2 % to 1.87 %. Conclusion: It was concluded that such heating process (which has been studied and reported in patents) absorbs the low- SFC fats of the cream, integrates them...

  8. Bubble Departure from Metal-Graphite Composite Surfaces and Its Effects on Pool Boiling Heat Transfer

    Science.gov (United States)

    Chao, David F.; Sankovic, John M.; Motil, Brian J.; Yang, W-J.; Zhang, Nengli

    2010-01-01

    The formation and growth processes of a bubble in the vicinity of graphite micro-fiber tips on metal-graphite composite boiling surfaces and their effects on boiling behavior are investigated. It is discovered that a large number of micro bubbles are formed first at the micro scratches and cavities on the metal matrix in pool boiling. By virtue of the non-wetting property of graphite, once the growing micro bubbles touch the graphite tips, the micro bubbles are sucked by the tips and merged into larger micro bubbles sitting on the end of the tips. The micro bubbles grow rapidly and coalesce to form macro bubbles, each spanning several tips. The necking process of a detaching macro bubble is analyzed. It is revealed that a liquid jet is produced by sudden break-off of the bubble throat. The composite surfaces not only have higher temperatures in micro- and macrolayers but also make higher frequency of the bubble departure, which increase the average heat fluxes in both the bubble growth stage and in the bubble departure period. Based on these analyses, the enhancement mechanism of pool boiling heat transfer on composite surfaces is clearly revealed.

  9. Vapor Grown Carbon Fiber/Phenolic Matrix Composites for Rocket Nozzles and Heat Shields

    Science.gov (United States)

    Patton, R. D.; Pittman, C. U., Jr.; Wang, L.; Day, A.; Hill, J. R.

    2001-01-01

    The ablation and mechanical and thermal properties of vapor grown carbon fiber (VGCF)/phenolic resin composites were evaluated to determine the potential of using this material in solid rocket motor nozzles. Composite specimens with varying VGCF loading (30%-50% wt) including one sample with ex-rayon carbon fiber plies were prepared and exposed to a plasma torch for 20 s with a heat flux of 16.5 MW/sq m at approximately 1650 C. Low erosion rates and little char formation were observed, confirming that these materials were promising for rocket motor nozzle materials. When fiber loadings increased, mechanical properties and ablative properties improved. The VGCF composites had low thermal conductivities (approximately 0.56 W/m-C) indicating they were good insulating materials. If a 65% fiber loading in VGCF composite can be achieved, then ablative properties are projected to be comparable to or better than the composite material currently used on the Space Shuttle Reusable Solid Rocket Motor (RSRM).

  10. INFLUENCE ОF MODIFIER THERMAL TREATMENT ОN CHARACTERISTICS ОF COMPOSITE MATERIALS FOR PROTECTIVE COATINGS

    Directory of Open Access Journals (Sweden)

    V. Ivashko

    2012-01-01

    Full Text Available This paper presents results that reveal influence of modifiers characterized by different nature and composition and subjected to heat treatment on operational characteristics of single and binary compositions. Interaction between dispersed clay particles and dependence of  coating properties on  their mass content in oligomeric and polymeric matrices have been justified in the paper. The paper contains data that prove an increase of coating hardness by 15–20 %. The coating composition includes thermally-treated dispersed clay particles.

  11. Experimental and Modelling Study of the Denaturation of Milk Protein by Heat Treatment.

    Science.gov (United States)

    Qian, Fang; Sun, Jiayue; Cao, Di; Tuo, Yanfeng; Jiang, Shujuan; Mu, Guangqing

    2017-01-01

    Heat treatment of milk aims to inhibit the growth of microbes, extend the shelf-life of products and improve the quality of the products. Heat treatment also leads to denaturation of whey protein and the formation of whey protein-casein polymer, which has negative effects on milk product. Hence the milk heat treatment conditions should be controlled in milk processing. In this study, the denaturation degree of whey protein and the combination degree of whey protein and casein when undergoing heat treatment were also determined by using the Native-PAGE and SDS-PAGE analysis. The results showed that the denaturation degree of whey protein and the combination degree of whey protein with casein extended with the increase of the heat-treated temperature and time. The effects of the heat-treated temperature and heat-treated time on the denaturation degree of whey protein and on the combination degree of whey protein and casein were well described using the quadratic regression equation. The analysis strategy used in this study reveals an intuitive and effective measure of the denaturation degree of whey protein, and the changes of milk protein under different heat treatment conditions efficiently and accurately in the dairy industry. It can be of great significance for dairy product proteins following processing treatments applied for dairy product manufacturing.

  12. 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.

  13. Influence of cultivar, soak treatment and brine composition on the ...

    African Journals Online (AJOL)

    The effect of cultivar, soak treatment and brine composition on physico-chemical and sensory properties of unpeeled whole canned tomatoes was investigated with a view to understanding the influence of these process conditions on the canned product characteristics. Two tomato cultivars (Lycopersicon esculentum Var.

  14. In-situ TEM Studies : Heat-treatment and Corrosion

    NARCIS (Netherlands)

    Malladi, S.R.K.

    2014-01-01

    Transmission electron microscopy (TEM) has been well known as a powerful characterisation tool to understand the structure and composition of various materials down to the atomic level. Over the years, several TEM studies have been carried out to understand the compositional, structural and

  15. Heat and Mass Transfer in the Chemical Vapor Deposition of Silicon Carbide in a Porous Carbon-Carbon Composite Material for a Heat Shield

    Science.gov (United States)

    Reznik, S. V.; Mikhailovskii, K. V.; Prosuntsov, P. V.

    2017-03-01

    Physical and mathematical simulations of the chemical vapor deposition of silicon carbide in a porous carbon-carbon composite material in a chemical vapor deposition reactor for formation of a matrix of a carbon-ceramic composite material for a heat shield of an aerospace aircraft have been performed. Results of parametric calculations of the heat and mass transfer at the macro- and microlevels in representative elements of the microstructure of carbon-carbon composite materials different in residual porosity at different temperatures in the reaction zone of the reactor are presented. Features of compaction of the pore space of a carbon-carbon composite material by a silicon-carbide matrix depending on the technological parameters of the reaction medium were analyzed.

  16. Influence of annealing heat treatment on pitting corrosion resistance of stainless steel type 316

    Directory of Open Access Journals (Sweden)

    Amirreza Bakhtiari

    2014-07-01

    Full Text Available The effect of annealing heat treatment on pitting resistance of stainless steel type 316L has been studied using Tafel polarization and ASTM G150 for estimating of the pitting potential and CPT, respectively. The materials were tested in 3.5% NaCl solution. The chemical composition of the material was analyzed via optical emission spectrometry. It was found that the sample treated at 940°C shows better pitting corrosion resistance than samples treated at 520°C and 820°C. The treatment at 940°C produced two types of morphologies, austenitic-ferritic matrix with δ-ferrite and only small amount of the σ phase. In the range up to 820°C the σ phase embedded in the γ phase matrix and at δ/γ interface was causing brittleness of the material and aggravated corrosion resistance. The treatment at 940°C produced the microstructure which prevented the corrosion attack to develop. It was revealed that the pitting size in samples treated at 520°C and 820°C is greater than that at 940°C. In addition, depth of pitting has been considered as a factor of pitting corrosion resistance. The depth of pitting in sample treated at 940°C is low since the pitting is almost superficial, while the pitting size in samples treated in 520°C and 820°C is higher and deeper.

  17. Unique effects of microwave heating on polymerization kinetics of poly(methyl methacrylate) composites

    Energy Technology Data Exchange (ETDEWEB)

    Spasojević, Pavle [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade (Serbia); Jovanović, Jelena, E-mail: jelenaj@ffh.bg.ac.rs [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11001 Belgrade (Serbia); Adnadjevic, Borivoj [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11001 Belgrade (Serbia)

    2013-09-16

    The effects of heating mode (conventional and microwave) on the kinetics of isothermal polymerization of MMA composite materials were investigated. Isothermal kinetics curves at temperature range from 343 K to 363 K for both conventional (CH) and microwave heating (MWH) were determined. It was found that the polymerization of MMA composite materials was kinetically elementary reaction for both CH and MWH. The kinetics of CH polymerization can be described by the model of phase-boundary controlled process (contracting volume), whereas the kinetics of MWH polymerization can be described by the model of first-order chemical reaction. The kinetics parameters (E{sub a} and ln A) of the polymerization under microwave heating are lower than for conventional heating. The established decreases in the activation energy and pre-exponential factor under the MWH compared to the CH is explained with the increase in the energy of ground vibrational level of the C–O valence vibrations (ν = 987 cm{sup −1}) in methyl methacrylate molecule and with the decrease in its anharmonicity factor which is caused with the selective resonant transfer of energy from the energetic reservoir to the oscillators in methyl methacrylate molecules. - Graphical abstract: Display Omitted - Highlights: • The MWH speeds the MMA material polymerization and changes the kinetics model. • A novel concept of MWH action based on activation complexes formation is presented. • The Selective Energy Transfer model is used to explain the effects of MWH. • The kinetics parameters under MWH are lower than for CH. • The activation energy for both MWH and CH polymerization is quantized.

  18. HARDENING OF THE ELECTRODESIEGED IRON CHEMICAL HEAT TREATMENT

    Directory of Open Access Journals (Sweden)

    V. I. Serebrovskii

    2015-01-01

    Full Text Available Summary. Currently in the repair and manufacture at the stage of recovery of steel parts, widely used special coatings formed by electrolytic effects on ferrous ions. This technique offers high performance, ease of implementation, low cost of technological equipment and materials used, as well as easy automation of the process. However, this method has several disadvantages: low fatigue strength of reconditioned parts, insufficiently strong grip of the iron coating to the substrate, particularly in alloy steels, insufficient wear resistance. For the purpose of increasing durability and wear resistance of parts, restored through electrochemical action, it is proposed to use chemical-heat treatment, consisting in the application of carbonitriding. Investigated the efficacy of different modes of carbonitriding in the highly carburizing paste-and their influence on the structure and properties of iron plating. It is established that the nitrocarburizing both low and high temperatures repeatedly (6-7.5 times increases the microhardness of the coatings. The highest hardness is obtained by low-temperature carbonitriding with direct quenching in water. Conducting the carbonitriding process at low temperatures (650 °C, significantly increases the hardness of the iron coatings, increasing the limit of its fluidity, a and also greatly increases its endurance limit. Nitrocarburized fatigue strength of samples with iron precipitation on the surface, as shown by our studies, not only higher strength of the same samples without carbonitriding (more than 2 times, but higher than the fatigue strength of the base metal without coatings. Raising the temperature of the carbonitriding did not increase the hardness of electrolytic iron. Developed a rational technology of hardening of steel parts, re-chain iron fortification. Selected optimum conditions for carbonitriding hardening restored iron fortification, with the purpose of increasing durability of machine

  19. Coarsening of carbides during different heat treatment conditions

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Kai, E-mail: miaok21@126.com; He, Yanlin, E-mail: ylhe@staff.shu.edu.cn; Zhu, Naqiong; Wang, Jingjing; Lu, Xiaogang; Li, Lin

    2015-02-15

    Highlights: • Coarsening of M{sub 7}C{sub 3} and V{sub 4}C{sub 3} carbides was quantitatively described in detail. • Cooling mode is a key factor to the simulation for the coarsening of carbides. • Coarsening of above spherical carbides can be calculated by Ostwald ripening model. • The interfacial energy between the γ matrix with M{sub 7}C{sub 3} and V{sub 4}C{sub 3} carbides are 0.7 J/m{sup 2}. - Abstract: Coarsening of carbides in 1# Fe-5.96Cr-0.35C (wt.%) alloy and 2# Fe-0.5V-0.53C (wt.%) alloy during different heat treatment conditions was investigated by carbon replica, high-resolution transmission electron microscopy (HRTEM) , X-ray diffraction (XRD) and SEM techniques. The equilibrium phases at 850 °C constitute of austenitic matrix (γ) + M{sub 7}C{sub 3} and austenite matrix (γ) + V{sub 4}C{sub 3} for 1# and 2# alloy respectively. Morphology of M{sub 7}C{sub 3} and V{sub 4}C{sub 3} carbides was mainly determined by cooling mode due to the different nucleation sites and growth mechanisms. Under directly aging condition, most carbides nucleate in the grain boundaries and grow into rod-shaped or flake-shaped particles by discontinuous growth mechanism. These particles turn out to be excluded during coarsening simulation using Oswald ripening model to give a more reasonable result. In addition, interfacial energy between M{sub 7}C{sub 3}/γ and V{sub 4}C{sub 3}/γ for the coarsening of M{sub 7}C{sub 3} and V{sub 4}C{sub 3} during aging at 850 °C is evaluated by fitting experimental data using thermodynamic and kinetic calculations. The interfacial energy is determined to be 0.7 J/m{sup 2} for the coarsening of M{sub 7}C{sub 3} and V{sub 4}C{sub 3} in austenitic matrix.

  20. Effects of Adiabatic Heating on the High Strain Rate Deformation of Polymer Matrix Composites

    Science.gov (United States)

    Sorini, Chris; Chattopadhyay, Aditi; Goldberg, Robert K.

    2017-01-01

    Polymer matrix composites (PMCs) are increasingly being used in aerospace structures that are expected to experience complex dynamic loading conditions throughout their lifetime. As such, a detailed understanding of the high strain rate behavior of the constituents, particularly the strain rate, temperature, and pressure dependent polymer matrix, is paramount. In this paper, preliminary efforts in modeling experimentally observed temperature rises due to plastic deformation in PMCs subjected to dynamic loading are presented. To this end, an existing isothermal viscoplastic polymer constitutive formulation is extended to model adiabatic conditions by incorporating temperature dependent elastic properties and modifying the components of the inelastic strain rate tensor to explicitly depend on temperature. It is demonstrated that the modified polymer constitutive model is capable of capturing strain rate and temperature dependent yield as well as thermal softening associated with the conversion of plastic work to heat at high rates of strain. The modified constitutive model is then embedded within a strength of materials based micromechanics framework to investigate the manifestation of matrix thermal softening, due to the conversion of plastic work to heat, on the high strain rate response of a T700Epon 862 (T700E862) unidirectional composite. Adiabatic model predictions for high strain rate composite longitudinal tensile, transverse tensile, and in-plane shear loading are presented. Results show a substantial deviation from isothermal conditions; significant thermal softening is observed for matrix dominated deformation modes (transverse tension and in-plane shear), highlighting the importance of accounting for the conversion of plastic work to heat in the polymer matrix in the high strain rate analysis of PMC structures.

  1. The use of superficial heat for treatment of temporomandibular disorders: an integrative review.

    Science.gov (United States)

    Furlan, Renata Maria Moreira Moraes; Giovanardi, Raquel Safar; Britto, Ana Teresa Brandão de Oliveira e; Oliveira e Britto, Denise Brandão de

    2015-01-01

    To perform an integrative review of scientific bibliographic production on the use of superficial heat treatment for temporomandibular disorders. Research strategy : Literature review was accomplished on PubMed, LiLACS, SciELO, Bireme, Web of Science, and BBO databases. The following descriptors were used: hot temperature, hyperthermia induced, heat transference, temporomandibular joint, temporomandibular joint disorders, temporomandibular joint dysfunction syndrome, and their equivalents in Portuguese and Spanish. Articles that addressed the superficial heat for the treatment of temporomandibular disorders, published in English, Spanish, or Portuguese, between 1980 and 2013. The following data were collected: technique of applying superficial heat, duration of application, stimulated body area, temperature of the stimulus, frequency of application, and benefits. initially, 211 studies were found, but just 13 contemplated the proposed selection criteria. Data were tabulated and presented in chronological order. Several techniques for superficial heat application on treatment of temporomandibular disorders were found in the literature. The moist heat was the most widely used technique. Many studies suggested the application of heat for at least 20 minutes once a day. Most authors recommended the application of heat in facial and cervical regions. The heat treatment resulted in significant relief of pain, reduced muscle tension, improved function of the mandible, and increased mouth opening.

  2. Thermal treatment of low permeability soils using electrical resistance heating

    Energy Technology Data Exchange (ETDEWEB)

    Udell, K.S. [Univ. of California, Berkeley, CA (United States)

    1996-08-01

    The acceleration of recovery rates of second phase liquid contaminants from the subsurface during gas or water pumping operations is realized by increasing the soil and ground water temperature. Electrical heating with AC current is one method of increasing the soil and groundwater temperature and has particular applicability to low permeability soils. Several mechanisms have been identified that account for the enhanced removal of the contaminants during electrical heating. These are vaporization of liquid contaminants with low boiling points, temperature-enhanced evaporation rates of semi-volatile components, and removal of residual contaminants by the boiling of residual water. Field scale studies of electrical heating and fluid extraction show the effectiveness of this technique and its applicability to contaminants found both above and below the water table and within low permeability soils. 10 refs., 8 figs.

  3. Characterization of Aluminum Magnesium Alloy Reverse Sensitized via Heat Treatment

    Science.gov (United States)

    2016-09-01

    during friction stir welding [25] and may be suited for heating Al-Mg alloys in the context of this study. LED arrays can be finely tuned and controlled...25] B. Baker et. al, "Use of High-Power diode Laser Arrays for Pre- and Post- Weld Heating During Friction Stir Welding of Steels," in Friction ...strength prior to welding , but lower yield strength than 5XXX series Al-Mg alloys following welding . This makes 5XXX series Al-Mg alloys the more

  4. Heat-Treatment Aqueous Two Phase System’ for Purification of Serine Protease from Kesinai (Streblus asper Leaves

    Directory of Open Access Journals (Sweden)

    Shuhaimi Mustafa

    2011-12-01

    Full Text Available A ‘Heat treatment aqueous two phase system’ was employed for the first time to purify serine protease from kesinai (Streblus asper leaves. In this study, introduction of heat treatment procedure in serine protease purification was investigated. In addition, the effects of different molecular weights of polyethylene glycol (PEG 4000, 6000 and 8000 at concentrations of 8, 16 and 21% (w/w as well as salts (Na-citrate, MgSO4 and K2HPO4 at concentrations of 12, 15, 18% (w/w on serine protease partition behavior were studied. Optimum conditions for serine protease purification were achieved in the PEG-rich phase with composition of 16% PEG6000-15% MgSO4. Also, thermal treatment of kesinai leaves at 55 °C for 15 min resulted in higher purity and recovery yield compared to the non-heat treatment sample. Furthermore, this study investigated the effects of various concentrations of NaCl addition (2, 4, 6 and 8% w/w and different pH (4, 7 and 9 on the optimization of the system to obtain high yields of the enzyme. The recovery of serine protease was significantly enhanced in the presence of 4% (w/w of NaCl at pH 7.0. Based on this system, the purification factor was increased 14.4 fold and achieved a high yield of 96.7%.

  5. The effects of heat treatment on the physical properties and surface roughness of Turkish Hazel (Corylus colurna L.) wood

    National Research Council Canada - National Science Library

    Korkut, Derya Sevim; Korkut, Süleyman; Bekar, Ilter; Budakçi, Mehmet; Dilik, Tuncer; Cakicier, Nevzat

    2008-01-01

    Heat treatment is often used to improve the dimensional stability of wood. In this study, the effects of heat treatment on the physical properties and surface roughness of Turkish Hazel (Corylus colurna L.) wood were examined...

  6. Effect of Pre-heating on Microtensile Bond Strength of Composite Resin to Dentin.

    Directory of Open Access Journals (Sweden)

    Abdolrahim Davari

    2014-10-01

    Full Text Available Direct composite resin restorations are widely used and the impact of different storage temperatures on composites is not well understood. The purpose of this study was to evaluate the microtensile bond strength of composite to dentin after different pre-curing temperatures.Occlusal surfaces of 44 human molars were ground with diamond burs under water coolant and polished with 600 grit silicon carbide papers to obtain flat dentin surfaces. The dentin was etched with 37% phosphoric acid and bonded with Adper Single Bond 2 according to the manufacturer's instructions. The specimens were randomly divided into two groups (n=22 according to the composite resin applied: FiltekP60 and Filtek Z250. Each group included three subgroups of composite resin pre-curing temperatures (4°C, 23°C and 37°C. Composite resins were applied to the dentin surfaces in a plastic mold (8mm in diameter and 4mm in length incrementally and cured. Twenty-two composite-to-dentin hour-glass sticks with one mm(2 cross-sectional area per group were prepared. Microtensile bond strength measurements were made using a universal testing machine at a crosshead speed of one mm/min. For statistical analysis, t-test, one-way and two-way ANOVA were used. The level of significance was set at P<0.05.Filtek P60 pre-heated at 37ºC had significantly higher microtensile bond strength than Filtek Z250 under the same condition. The microtensile bond strengths were not significantly different at 4ºC, 23ºC and 37ºC subgroups of each composite resin group.Filtek P60 and Filtek Z250 did not have significantly different microtensile bond strengths at 4ºC and 23ºC but Filtek P60 had significantly higher microtensile bond strength at 37 ºC. Composite and temperature interactions had significant effects on the bond strength.

  7. Stone heat treatment in the Early Mesolithic of southwestern Germany: Interpretation and identification.

    Science.gov (United States)

    Schmidt, Patrick; Spinelli Sanchez, Océane; Kind, Claus-Joachim

    2017-01-01

    The Early Mesolithic of southwestern Germany, the so-called Beuronian (9600-7100 BC), is a period of important transformations in the way people lived, in their subsistence and in the stone tools they produced. One of the perhaps most spectacular re-inventions of that time is heat treatment of stones prior to their manufacture into tools. Although heat treatment has been understood as one of the defining characteristics of the Beuronian of southwestern Germany, and although its existence has been known for almost 30 years now, relatively few systematic studies on it are available. In this paper, we present such a study, aiming to shed light on two questions: (1) what technique and heating parameters were used in the Beuronian and (2) how reliable are the macroscopic proxies traditionally used to identify heat treatment in this context? We investigate these questions using a non-destructive archaeometric technique for measuring past heating temperatures of heat-treated stones and a quantitative surface roughness analysis aiming to understand the relations between surface aspect and heat treatment. These methods are applied to 46 Jurassic chert artefacts from the site Helga-Abri located in the Swabian Alb region of southwestern Germany. Our results document that an opportunistic low-investment procedure was used to heat stone, probably relying on the use of the above-ground part of regular camp-fires. We also found that the traditionally used macroscopic criteria, such as colour and surface gloss, cannot be unambiguously used to identify heat treatment in assemblages made from Jurassic chert. These findings have important implications for our understanding of the Beuronian lithic chaîne opératoire in terms of the investment in time and resources necessary, and for the refinement of archaeological techniques used to identify heat treatment in the Mesolithic of the Swabian Alb.

  8. Stone heat treatment in the Early Mesolithic of southwestern Germany: Interpretation and identification.

    Directory of Open Access Journals (Sweden)

    Patrick Schmidt

    Full Text Available The Early Mesolithic of southwestern Germany, the so-called Beuronian (9600-7100 BC, is a period of important transformations in the way people lived, in their subsistence and in the stone tools they produced. One of the perhaps most spectacular re-inventions of that time is heat treatment of stones prior to their manufacture into tools. Although heat treatment has been understood as one of the defining characteristics of the Beuronian of southwestern Germany, and although its existence has been known for almost 30 years now, relatively few systematic studies on it are available. In this paper, we present such a study, aiming to shed light on two questions: (1 what technique and heating parameters were used in the Beuronian and (2 how reliable are the macroscopic proxies traditionally used to identify heat treatment in this context? We investigate these questions using a non-destructive archaeometric technique for measuring past heating temperatures of heat-treated stones and a quantitative surface roughness analysis aiming to understand the relations between surface aspect and heat treatment. These methods are applied to 46 Jurassic chert artefacts from the site Helga-Abri located in the Swabian Alb region of southwestern Germany. Our results document that an opportunistic low-investment procedure was used to heat stone, probably relying on the use of the above-ground part of regular camp-fires. We also found that the traditionally used macroscopic criteria, such as colour and surface gloss, cannot be unambiguously used to identify heat treatment in assemblages made from Jurassic chert. These findings have important implications for our understanding of the Beuronian lithic chaîne opératoire in terms of the investment in time and resources necessary, and for the refinement of archaeological techniques used to identify heat treatment in the Mesolithic of the Swabian Alb.

  9. A study of the impact of moist-heat and dry-heat treatment processes on hazardous trace elements migration in food waste.

    Science.gov (United States)

    Chen, Ting; Jin, Yiying; Qiu, Xiaopeng; Chen, Xin

    2015-03-01

    Using laboratory experiments, the authors investigated the impact of dry-heat and moist-heat treatment processes on hazardous trace elements (As, Hg, Cd, Cr, and Pb) in food waste and explored their distribution patterns for three waste components: oil, aqueous, and solid components. The results indicated that an insignificant reduction of hazardous trace elements in heat-treated waste-0.61-14.29% after moist-heat treatment and 4.53-12.25% after dry-heat treatment-and a significant reduction in hazardous trace elements (except for Hg without external addition) after centrifugal dehydration (P heat treatment, over 90% of the hazardous trace elements in the waste were detected in the aqueous and solid components, whereas only a trace amount of hazardous trace elements was detected in the oil component (heat treatment process did not significantly reduce the concentration of hazardous trace elements in food waste, but the separation process for solid and aqueous components, such as centrifugal dehydration, could reduce the risk considerably. Finally, combined with the separation technology for solid and liquid components, dry-heat treatment is superior to moist-heat treatment on the removal of external water-soluble ionic hazardous trace elements. An insignificant reduction of hazardous trace elements in heat-treated waste showed that heat treatment does not reduce trace elements contamination in food waste considerably, whereas the separation process for solid and aqueous components, such as centrifugal dehydration, could reduce the risk significantly. Moreover, combined with the separation technology for solid and liquid components, dry-heat treatment is superior to moist-heat treatment for the removal of external water-soluble ionic hazardous trace elements, by exploring distribution patterns of trace elements in three waste components: oil, aqueous, and solid components.

  10. Radio Frequency Heat Treatments to Disinfest Dried Pulses of Cowpea Weevil

    Science.gov (United States)

    To explore the potential of radio frequency (RF) heat treatments as an alternative to chemical fumigants for disinfestation of dried pulses, the relative heat tolerance and dielectric properties of different stages of the cowpea weevil (Callosobruchus maculatus) was determined. Among the immature st...

  11. 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

  12. Reactions of lactose during heat treatment of milk : a quantitative study

    NARCIS (Netherlands)

    Berg, H.E.

    1993-01-01

    The kinetics of the chemical reactions of lactose during heat treatment of milk were studied. Skim milk and model solutions resembling milk were heated. Reaction products were determined and the influence of varying lactose, casein and fat concentration on the formation of these products

  13. Composition of sweat of the horse during prolonged epinephrine (adrenaline) infusion, heat exposure, and exercise.

    Science.gov (United States)

    Kerr, M G; Snow, D H

    1983-08-01

    Temporal changes in sweat composition were studied in 4 horses during epinephrine (adrenaline) infusion (0.13 to 0.31 micrograms/kg/min for 3 hours), heat exposure (41 C, [33 C wet bulb] for 5 to 6 hours), and exercise (16 to 18 km/hr for 58 to 80 km). Four ponies also were studied during heat exposure. Sweat produced by each of the stimuli was hypertonic for Na+, K+, and Cl-. These electrolyte concentrations remained constant during the central period of the experiments, with changes occurring near the beginning and toward the end. The Na+ was significantly higher and K+ significantly lower in epinephrine-induced sweat than in heat-induced sweat, and the pattern of change in sweat Na/K ratio varied among the 3 stimuli. The Ca2+ concentration decreased with time and was hypotonic after 15 minutes of epinephrine-induced sweating. Concentrations of Mg2+ and protein decreased exponentially with time. There was a high correlation between them, although the Mg2+ was not protein-bound. Sweat urea concentration was directly related to plasma urea concentration. When plasma glucose concentration became greater than 10 to 12 mmole/L during epinephrine infusion, glucose appeared in the sweat and its concentration rose to 8 to 12 mmole/L of sweat when plasma glucose was more than 20 mmole/L.

  14. Creep properties of PWC-11 base metal and weldments as affected by heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Titran, R.H.; Moore, T.J.; Grobstein, T.L. [Lewis Research Center, Cleveland, OH (United States)

    1994-09-01

    In a preliminary study using single specimens for each condition, PWC-11 (a niobium-base alloy with a nominal composition of Nb-1%Zr-0.1%C) was creep tested at 1350 K and 40 MPa. Base metal specimens and specimens with transverse electrode beam welds were tested with and without a 1000 hr, 1350 K aging treatment prior to testing. In the annealed condition (1 hr at 1755 K + 2 hr at 1475 K), the base metal exhibited superior creep strength compared to the aged condition, reaching 1 percent strain in 3480 hr. A 1000 hr, 1350 K aging treatment prior to creep testing had a severe detrimental effect on creep strength of the base metal and transverse electron beam weldments, reducing the time to attain 1 percent strain by an order of magnitude. Extrapolated temperature compensated creep rates indicate that the present heat of PWC-11 may be four times as creep resistance as similarly tested Nb-1%Zr. The extrapolated stress to achieve 1 percent creep strain in 7 yr at 1350 K is 0.6 MPa for annealed Nb-1%Zr and 2.8 MPa for annealed and aged PWC-11 base metal with and without a transverse electron beam weld.

  15. Advances in the Lightweight Air-Liquid Composite Heat Exchanger Development for Space Exploration Applications

    Science.gov (United States)

    Shin, E. Eugene; Johnston, J. Chris; Haas, Daniel

    2011-01-01

    An advanced, lightweight composite modular Air/Liquid (A/L) Heat Exchanger (HX) Prototype for potential space exploration thermal management applications was successfully designed, manufactured, and tested. This full-scale Prototype consisting of 19 modules, based on recommendations from its predecessor Engineering Development unit (EDU) but with improved thermal characteristics and manufacturability, was 11.2 % lighter than the EDU and achieves potentially a 42.7% weight reduction from the existing state-of-the-art metallic HX demonstrator. However, its higher pressure drop (0.58 psid vs. 0.16 psid of the metal HX) has to be mitigated by foam material optimizations and design modifications including a more systematic air channel design. Scalability of the Prototype design was validated experimentally by comparing manufacturability and performance between the 2-module coupon and the 19-module Prototype. The Prototype utilized the thermally conductive open-cell carbon foam material but with lower density and adopted a novel high-efficiency cooling system with significantly increased heat transfer contact surface areas, improved fabricability and manufacturability compared to the EDU. Even though the Prototype was required to meet both the thermal and the structural specifications, accomplishing the thermal requirement was a higher priority goal for this first version. Overall, the Prototype outperformed both the EDU and the corresponding metal HX, particularly in terms of specific heat transfer, but achieved 93.4% of the target. The next generation Prototype to achieve the specification target, 3,450W would need 24 core modules based on the simple scaling factor. The scale-up Prototype will weigh about 14.7 Kg vs. 21.6 Kg for the metal counterpart. The advancement of this lightweight composite HX development from the original feasibility test coupons to EDU to Prototype is discussed in this paper.

  16. Simulation of Distortion and Residual Stress Development During Heat Treatment of Steel Castings

    Energy Technology Data Exchange (ETDEWEB)

    Beckermann, Christoph; Carlson, Kent

    2011-07-22

    Heat treatment and associated processing, such as quenching, are critical during high strength steel casting production. These processes must be managed closely to prevent thermal and residual stresses that may result in distortion, cracking (particularly after machining), re-work, and weld repair. The risk of casting distortion limits aggressive quenching that can be beneficial to the process and yield an improved outcome. As a result of these distortions, adjustments must be made to the casting or pattern design, or tie bars must be added. Straightening castings after heat treatments can be both time-consuming and expensive. Residual stresses may reduce a casting's overall service performance, possibly resulting in catastrophic failure. Stress relieving may help, but expends additional energy in the process. Casting software is very limited in predicting distortions during heat treatment, so corrective measures most often involve a tedious trial-and-error procedure. An extensive review of existing heat treatment residual stress and distortion modeling revealed that it is vital to predict the phase transformations and microstructure of the steel along with the thermal stress development during heat treatment. After reviewing the state-of-the-art in heat treatment residual stress and distortion modeling, an existing commercial code was selected because of its advanced capabilities in predicting phase transformations, the evolving microstructure and related properties along with thermal stress development during heat treatment. However, this software was developed for small parts created from forgings or machined stock, and not for steel castings. Therefore, its predictive capabilities for heat treatment of steel castings were investigated. Available experimental steel casting heat treatment data was determined to be of insufficient detail and breadth, and so new heat treatment experiments were designed and performed, casting and heat treating modified versions

  17. Effects of heat treatment and welding process on superelastic behaviour and microstructure of micro electron beam welded NiTi

    Directory of Open Access Journals (Sweden)

    Balz Isabel

    2016-09-01

    Full Text Available Medical devices with small dimensions made of superelastic NiTi become more popular, but joining these parts remains challenging. Since laser welding was found to be an option, electron beam welding seems to be an interesting alternative as it provides additional advantages due to the precise beam positioning and the high vacuum. Superelasticity is influenced by microstructure and surface layer composition that are mainly affected by welding process and by heat treatment and therefore will be investigated in the present paper.

  18. Effect of Heat Treatment on Machining Properties of the AlSi9Cu3(Fe Alloy

    Directory of Open Access Journals (Sweden)

    Wieroński P.

    2016-09-01

    Full Text Available Automation of machining operations, being result of mass volume production of components, imposes more restrictive requirements concerning mechanical properties of starting materials, inclusive of machinability mainly. In stage of preparation of material, the machinability is influenced by such factors as chemical composition, structure, mechanical properties, plastic working and heat treatment, as well as a factors present during machining operations, as machining type, cutting parameters, material and geometry of cutting tools, stiffness of the system: workpiece – machine tool – fixture and cutting tool.

  19. Heat treatment effect on erosion behavior of poly(methylmethacrylate) for optical transmittance efficiency

    Science.gov (United States)

    Çoban, Onur

    2014-10-01

    Influence of heat treatment on optical transmittance of poly(methyl methacrylate) (PMMA) samples was investigated under solid particle erosion. Heat treatment was employed at 85 °C for 1, 2 and 3 h. Effect of heat treatment on physical, chemical, mechanical and thermal properties of PMMA samples was investigated by differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, Vickers microhardness measurement methods. After these analysis, both pristine and heat treated PMMA samples were eroded at 15°, 30°, 45°, 60°, 75° and 90° impingement angles. Then, optical transmittance of all eroded PMMA samples was inspected by a UV-Vis spectrometer. Scanning electron microscopy (SEM) was used to explain the erosion mechanisms and to compare the roughness and optical transmittance of eroded PMMA surfaces. Heat treatment under glass transition temperature of PMMA increased the Tg and hardness values. According to erosion test results, both pristine and heat treated PMMA samples were showed ductile erosion behavior. However; maximum and minimum optical transmittance values of eroded pristine PMMA samples were obtained for the angles of 15° and 90°, respectively. A positive effect of heat treatment on optical transmittance of PMMA was obtained for all impingement angles, but most pronounced effect was seen for 15°.

  20. EFFECT OF HEAT TREATMENT ON ANTIOXIDANT ACTIVITY OF SOME SPICES

    OpenAIRE

    Ademoyegun Olufemi Temitope; Adewuyi Gregory Olufemi; Fariyike Timothy Alaba

    2010-01-01

    Spices show potential health benefits as they possess antioxidant activity. The study was to determine the effect of cooking on the antioxidant activity of some selected spices. The total phenol content of five spices (Onion, Garlic, Ginger, Turmeric, and Basil) was determined at different heating periods (1h and 2 h) at 1000c. Although these dietary spice are resistant to thermal denaturation, interestingly, in the case of onion shows reduction in all the tested activities and others show...

  1. Reproducibility of High-Q SRF Cavities by High Temperature Heat Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Dhakal, Pashupati [JLAB; Ciovati, Gianluigi [JLAB; Kneisel, Peter [JLAB; Myneni, Ganapati Rao [JLAB

    2014-07-01

    Recent work on high-temperature (> 600 °C) heat treatment of ingot Nb cavities in a customized vacuum furnace for several hours showed the possibility of achieving Q0-values of up to ~5×1010 at 2.0 K, 1.5 GHz and accelerating gradients of ~20 MV/m. This contribution presents results on further studies of the heat treatment process to produce cavities with high Q0 values for continuous-wave accelerator application. Single-cell cavities of different Nb purity have been processed through few cycles of heat-treatments and chemical etching. Measurements of Q0 as a function of temperature at low RF field and of Q0 as a function of the RF field at or below 2.0 K have been made after each treatment. Measurements by TOF-SIMS of the impurities depth profiles were made on samples heat treated with the cavities.

  2. Effects of Mead Wort Heat Treatment on the Mead Fermentation Process and Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Sławomir Czabaj

    2017-05-01

    Full Text Available The effects of mead wort heat treatment on the mead fermentation process and antioxidant activity were tested. The experiment was conducted with the use of two different honeys (multiflorous and honeydew collected from the Lower Silesia region (Poland. Heat treatment was performed with the use of a traditional technique (gently boiling, the more commonly used pasteurization, and without heat treatment (control. During the experiment fermentation dynamics were monitored using high performance liquid chromatography with refractive index detection (HPLC-RID. Total antioxidant capacity (TAC and total phenolic content (TPC were estimated for worts and meads using UV/Vis spectrophotometric analysis. The formation of 5-hydroxymethylfurfural (HMF was monitored by HPLC analyses. Heat treatment had a great impact on the final antioxidant capacity of meads.

  3. Effect of Carbon Nanofiber Heat Treatment on Physical Properties of Polymeric Nanocomposites—Part I

    Directory of Open Access Journals (Sweden)

    Khalid Lafdi

    2007-01-01

    Full Text Available The definition of a nanocomposite material has broadened significantly to encompass a large variety of systems made of dissimilar components and mixed at the nanometer scale. The properties of nanocomposite materials also depend on the morphology, crystallinity, and interfacial characteristics of the individual constituents. In the current work, vapor-grown carbon nanofibers were subjected to varying heat-treatment temperatures. The strength of adhesion between the nanofiber and an epoxy (thermoset matrix was characterized by the flexural strength and modulus. Heat treatment to 1800C∘ demonstrated maximum improvement in mechanical properties over that of the neat resin, while heat-treatment to higher temperatures demonstrated a slight decrease in mechanical properties likely due to the elimination of potential bonding sites caused by the elimination of the truncated edges of the graphene layers. Both the electrical and thermal properties of the resulting nanocomposites increased in conjunction with the increasing heat-treatment temperature.

  4. Influence of Heat Treatment on the Bending Behaviour of LLDPE Monofilaments

    Directory of Open Access Journals (Sweden)

    Kolgjini Blerina

    2014-09-01

    Full Text Available It is known that artificial turf surfaces based on LLDPE monofilaments have the potential to replace natural turf surfaces used for several sport surfaces. Even though the production parameters have a strong influence on the behaviour of monofilaments and indirectly on the final product, the effect of heat treatment at different stages of the production lines is not studied in detail. Therefore, the influence of heat treatment during the production of monofilaments was investigated. This investigation includes a study of the mechanical properties such as tensile testing and bending behaviour and morphological analyses by employing DSC measurements. The results show that the applied heat treatment has a strong influence on the bending behaviour even though the classical studied morphology structures do not show significant changes. Heat treatment influences quite importantly the characteristics of the non-crystalline part of the monofilaments and results in better long-term properties, such as resilience, deformation recovery and fibrillation resistance.

  5. Microhardness of heat cure acrylic resin after treatment with disinfectants.

    Science.gov (United States)

    Amin, Faiza; Rehman, Abdur; Abbas, Muhammad

    2015-08-01

    To evaluate the effect of disinfectants and distilled water on the micro-hardness of heat cure acrylic resins. The case-control study was conducted at Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences, and Nadirshaw Edulji Dinshaw University of Engineering and Technology, Karachi, from April to October 2011. Specimens were fabricated from heat cure acrylic resin material and they were divided into four equal groups. Group 1 was evaluated at baseline and was taken as the control group. Group 2 was immersed in distilled water for 20 minutes, Group 3 in1% sodium hypochlorite for 20 minutes, and Group 4 in 2% alkaline gluteraldehyde for 10 minutes. All specimens were polished, stored in distilled water for 24 hours prior to experiment. All the specimens were immersed twice daily for a total of 60 days after which they were tested for Vickers micro-hardness test. Statistical analysis was conducted with one-way analysis of variance and Tukey post hoc test (a=0.05). There were 72 specimens divided into four groups of 18(25%) each. Statistically significant differences were found among all groups (pacrylic resins. Group 4 showed the most reduction in the hardness value which was followed by Group 3. The hardness of heat cure acrylic resin was affected by disinfectants.

  6. TEM Characterization and Properties of Cu-1 wt.% TiB2 Nanocomposite Prepared by Rapid Solidification and Subsequent Heat Treatment

    Directory of Open Access Journals (Sweden)

    M. Sobhani

    2012-12-01

    Full Text Available Copper matrix composite reinforced by 1wt.% TiB2 particles was prepared using in situ reaction of Cu-1.4wt.% Ti and Cu-0.7wt.% B by rapid solidification and subsequent heat treatment for 1-20 hrs at 900ºC. High-resolution transmission electron microscopy (HRTEM characterization showed that primary TiB2 particles were formed in liquid copper. Heat treatment of as-solidified samples led to the formation of secondary TiB2 particles via spinodal decomposition of titanium-rich zone inside the grains. Mechanical properties (after 50% reduction in area as well as electrical conductivity of composite were evaluated after heat treatment and were compared with those of pure copper. The results indicated that, due to the formation of secondary TiB2 particles in the matrix, electrical conductivity increased along with hardness up to 10 hrs of heat treatment and reached 65% IACS and 155 HV, respectively. Moreover, the maximum ultimate (i.e. 580 MPa and yield (i.e. 555 MPa strengths of composite were achieved at this time.

  7. Bioactive carbon-PEEK composites prepared by chemical surface treatment.

    Science.gov (United States)

    Miyazaki, Toshiki; Matsunami, Chisato; Shirosaki, Yuki

    2017-01-01

    Polyetheretherketone (PEEK) has attracted much attention as an artificial intervertebral spacer for spinal reconstruction. Furthermore, PEEK plastic reinforced with carbon fiber has twice the bending strength of pure PEEK. However, the PEEK-based materials do not show ability for direct bone bonding, i.e., bioactivity. Although several trials have been conducted for enabling PEEK with bioactivity, few studies have reported on bioactive surface modification of carbon-PEEK composites. In the present study, we attempted the preparation of bioactive carbon-PEEK composites by chemical treatments with H2SO4 and CaCl2. Bioactivity was evaluated by in vitro apatite formation in simulated body fluid (SBF). The apatite formation on the carbon-PEEK composite was compared with that of pure PEEK. Both pure PEEK and carbon-PEEK composite formed the apatite in SBF when they were treated with H2SO4 and CaCl2; the latter showed higher apatite-forming ability than the former. It is conjectured that many functional groups able to induce the apatite nucleation, such as sulfo and carboxyl groups, are incorporated into the dispersed carbon phase in the carbon-PEEK composites. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Influence of heat treatment on antioxidant capacity and (poly)phenolic compounds of selected vegetables

    OpenAIRE

    Juaniz, I. (Isabel); Ludwig, I.A. (Iziar A.); Huarte, E; Pereira-Caro, G.; Moreno-Rojas, J.M.; Cid, C. (Concepción); Peña, M.P. (María Paz) de

    2016-01-01

    The impact of cooking heat treatments (frying in olive oil, frying in sunflower oil and griddled) on the antioxidant capacity and (poly)phenolic compounds of onion, green pepper and cardoon, was evaluated. The main compounds were quercetin and isorhamnetin derivates in onion, quercetin and luteolin derivates in green pepper samples, and chlorogenic acids in cardoon. All heat treatments tended to increase the concentration of phenolic compounds in vegetables suggesting a thermal destruction of...

  9. Produktivitas Benih Cabai Rawit Setelah Diperlakukan Dry Heat Treatment dan Penyimpanan

    OpenAIRE

    I GUSTI NGURAH RAKA; I DEWA NYOMAN NYANA; NI LUH MADE PRADNYAWATHI

    2015-01-01

    Productivity of Pepper Seeds Which are Treated Dry Heat Treatment and Storage Pepper plants (Capsicum frutescens L.) is one type of horticultural crops which is very high usage levels therefor, it is necessary to increase productivity dramatically. One effort to fulfil the need is preparing healthy seed with long shelf life . This study aims to determine the growth and yield of pepper plants whose seed was treated with dry heat treatment and storage. The experiment was conducted in Br . Marga...

  10. The long-term effects of a life-prolonging heat treatment on the Drosophila melanogaster transcriptome suggest that heat shock proteins extend lifespan

    DEFF Research Database (Denmark)

    Sarup, Pernille Merete; Sørensen, Peter; Loeschcke, Volker

    2014-01-01

    Heat-induced hormesis, i.e. the beneficial effect of mild heat-induced stress, increases the average lifespan of many organisms. This effect, which depends on the heat shock factor, decreases the log mortality rate weeks after the stress has ceased. To identify candidate genes that mediate...... this lifespan-prolonging effect late in life, we treated flies with mild heat stress (34 °C for 2 h) 3 times early in life and compared the transcriptomic response in these flies versus non-heat-treated controls 10–51 days after the last heat treatment. We found significant transcriptomic changes in the heat......-treated flies. Several hsp70 probe sets were up-regulated 1.7–2-fold in the mildly stressed flies weeks after the last heat treatment (P stress. We...

  11. Effect of Heat Assisted Bath Sonication on the Mechanical and Thermal Deformation Behaviours of Graphene Nanoplatelets Filled Epoxy Polymer Composites

    Directory of Open Access Journals (Sweden)

    Jin-Luen Phua

    2016-01-01

    Full Text Available Graphene nanoplatelets (GNP filled epoxy composites ranged from 0.2 to 5 vol.% were prepared in this study using simple heat assisted bath sonication for better GNP dispersion and exfoliation. The effects of GNP filler loading via heat assisted bath sonication on the mechanical properties and thermal deformation behaviour were investigated. Improvements on flexural strength and fracture toughness up to 0.4 vol.% filler loading were recorded. Further addition of GNP filler loading shows a deteriorating behaviour on the mechanical properties on the composites. The bulk electrical conductivity of the epoxy composites is greatly improved with the addition of GNP filler loading up to 1 vol.%. The thermal expansion of epoxy composites is reduced with the addition of GNP; however poor thermal stability of the composites is observed.

  12. Influence of heat treatment on the structural, morphological and ...

    Indian Academy of Sciences (India)

    ... and quartz substrates by sputtering composite target of Ti80Si20 using reactive DC magnetron sputtering method. The as-deposited films were annealed in oxygenatmosphere at different temperatures in the range 400–900 ∘ C. X-ray photoelectron spectroscopic indicated that the as-deposited films formed at oxygen flow ...

  13. Mapping QTLs associated to germination stability following dry-heat treatment in rice seed.

    Science.gov (United States)

    Lee, Seung-Yeob; Kim, Yong-Hwan; Lee, Gang-Seob

    2017-07-01

    Using 164 recombinant inbred lines (RILs) derived from a cross between Milyang 23 (indica/japonica) and Gihobyeo (japonica) in rice, dry-heat tolerance was evaluated for the seeds of parents and RILs, whose dormancy was naturally broken in six months after harvesting. Mapping QTLs associated to dry-heat tolerance was carried out through interval mapping using Qgene 3.0. Seed germination after dry-heat treatments (90 °C for 24 h) showed a significant difference between the two parents, when evaluated for percentage germination and mean germination time. Milyang 23 was highly tolerant to the dry-heat treatment, while Gihobyeo was sensitive. Three QTLs (qDHT 1, qDHT 5, and qDHT 7) conferring the dry-heat tolerance were mapped to chromosomes 1, 5 and 7, respectively. qDHT 1 on chromosome 1 was tightly linked at 4 cM from ME1-1. The phenotypic variation explained by the three QTLs was 27.18% of the total variance in the 164 RIL populations, and the parental additive effects of three QTLs affected the Milyang 23 allele increased dry-heat tolerance. The detection of new QTLs associated with dry-heat tolerance will provide important information for disease and insect control, using dry-heat treatment in organic or low input sustainable agriculture.

  14. Heat

    CERN Document Server

    Lawrence, Ellen

    2016-01-01

    Is it possible to make heat by rubbing your hands together? Why does an ice cube melt when you hold it? In this title, students will conduct experiments to help them understand what heat is. Kids will also investigate concepts such as which materials are good at conducting heat and which are the best insulators. Using everyday items that can easily be found around the house, students will transform into scientists as they carry out step-by-step experiments to answer interesting questions. Along the way, children will pick up important scientific skills. Heat includes seven experiments with detailed, age-appropriate instructions, surprising facts and background information, a "conclusions" section to pull all the concepts in the book together, and a glossary of science words. Colorful, dynamic designs and images truly put the FUN into FUN-damental Experiments.

  15. Effect of heat treatment on microstructural and optical properties of CBD grown Al-doped ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chandramohan, R., E-mail: rathinam.chandramohan@gmail.com [Department of Physics, Sree Sevugan Annamalai College, College Road, Devakottai 630303 (India); Vijayan, T.A. [Department of Physics, Sree Sevugan Annamalai College, College Road, Devakottai 630303 (India); Arumugam, S.; Ramalingam, H.B. [Department of Physics, Government Arts College, Udumalpet 642126 (India); Dhanasekaran, V.; Sundaram, K.; Mahalingam, T. [Department of Physics, Alagappa University, Karaikudi 630003 (India)

    2011-02-15

    Research highlights: > Effect of annealing temperature on Al-doped ZnO thin films. > Microstructural properties of Al-doped ZnO thin films. > Optical constants are found to increase with increase of heat treatment. - Abstract: Investigations on the effect of annealing temperature on the structural, optical properties and morphology of Al-doped ZnO thin films deposited on glass substrate by chemical bath deposition have been carried out. X-ray diffraction studies revealed that deposited films are in polycrystalline nature with hexagonal structure along the (0 0 2) crystallographic plane. Microstructural properties of films such as crystallite size, texture coefficient, stacking fault probability and microstrain were calculated from predominant (0 0 2) diffraction lines. The UV-Vis-NIR spectroscopy studies revealed that all the films have high optical transmittance (>60%) in the visible range. The optical band gap values are found to be in the range of 3.25-3.31 eV. Optical constants have been estimated and the values of n and k are found to increase with increase of heat treatment. The films have increased transmittance with increase of heat treatment. Al-doped ZnO thin films fabricated by this simple and economic chemical bath deposition technique without using any carrier gas are found to be good in structural and optical properties which are desirable for photovoltaic applications. Scanning electron microscopic images revealed that the hexagonal shaped grains that occupy the entire surface of the film with its near stoichiometric composition.

  16. Effects of vacuum heat treatment on the photoelectric work function and surface morphology of multilayered silver–metal electrical contacts

    Energy Technology Data Exchange (ETDEWEB)

    Akbi, Mohamed, E-mail: akbi_mohamed@umbb.dz [Laboratoire “Arc Electrique et Plasmas Thermiques”, CNRS, UPRES-A 6069, 24, Avenue des Landais, F-63177 Aubière Cedex (France); Department of Physics, Faculty of Sciences, University of Boumerdes (UMBB), Independence Avenue, 35000 Boumerdes (Algeria); Bouchou, Aïssa [Faculty of Physics, University of Algiers (USTHB), B.P. 32, El-Alia, Bab-Ezzouar, 16111 Algiers (Algeria); Zouache, Noureddine [Laboratoire “Arc Electrique et Plasmas Thermiques”, CNRS, UPRES-A 6069, 24, Avenue des Landais, F-63177 Aubière Cedex (France)

    2014-06-01

    Contact materials used for electrical breakers are often made with silver alloys. Mechanical and thermodynamical properties as well as electron emission of such complicated alloys present a lack of reliable and accurate experimental data. This paper deals mainly with electron work function (EWF) measurements about silver–metal (Ag–Me) electrical contacts (Ag–Ni (60/40) and Ag–W (50/50)), before and after surface heat treatments at 513 K–873 K, under UHV conditions (residual gas pressure of 1.4 × 10{sup −7} mbar). The electron work function (EWF) of silver alloyed contacts was measured photoelectrically, using both Fowler's method of isothermal curves and linearized Fowler plots. An interesting fact brought to light by this investigation is that after vacuum heat treatments, the diffusion and/or evaporation phenomena, affecting the atomic composition of the alloy surface, somehow confine the EWF of the silver–nickel alloy, Φ(Ag–Ni), determined at room temperature in interval]Φ(Ag), Φ(Ni) [=] 4.26 eV, 4.51 eV[. Surface analysis of two specimens before and after heating showed a significant increase of tungsten atomic proportion on the contact surface for Ag–W contacts after VH treatments. A multilayer model, taking into account the strong intergranular and volume segregation gives a good interpretation of the obtained results.

  17. Heat-treatment controlled structural and optical properties of sol-gel fabricated Eu:ZnO thin films

    Science.gov (United States)

    Ghosh, Subhabrata; Uma Mahendra Kumar, K.; Bhaktha, B. N. Shivakiran

    2017-02-01

    We report on the fabrication of sol-gel derived Eu-doped ZnO films and the effects of heat-treatment on their structural and optical properties. X-ray diffraction data analysis confirms the decrease in strain in the thin films with increasing heat-treatment temperatures, and the compressive stress of the samples is found to become tensile for heat-treatments between 650 °C and 800 °C. X-ray-absorption fine-structure spectra performed at the Eu L3-edge confirm the absence of clustering of Eu-ions. The photoluminescence (PL) spectra of undoped and doped films consist of near-band edge emissions along with the defect state emissions of ZnO. Intense red emission (612 nm) is observed under UV excitation attributed to the 5D0 →7F2 energy level transition of Eu3+ ions in the doped films. The elemental composition and the existence of Eu2+ as well as Eu3+ has been discussed with the help of X-ray photoelectron spectroscopy. ZnO → Eu3+ energy transfer has also been confirmed with the help of PL excitation spectra in these transparent ZnO thin films for applications in integrated optic devices operating in the UV-visible region.

  18. Graphene transport properties upon exposure to PMMA processing and heat treatments

    DEFF Research Database (Denmark)

    Gammelgaard, Lene; Caridad, Jose; Cagliani, Alberto

    2014-01-01

    The evolution of graphene's electrical transport properties due to processing with the polymer polymethyl methacrylate (PMMA) and heat are examined in this study. The use of stencil (shadow mask) lithography enables fabrication of graphene devices without the usage of polymers, chemicals or heat......, allowing us to measure the evolution of the electrical transport properties during individual processing steps from the initial as-exfoliated to the PMMA-processed graphene. Heating generally promotes the conformation of graphene to SiO2 and is found to play a major role for the electrical properties...... that flakes conforming poorly to the substrate will have a higher carrier mobility which will however be reduced as heat treatment enhance the conformation. We finally show the electrical properties of graphene to be reversible upon heat treatments in air up to 200°C....

  19. Ruminal Biohydrogenation Kinetics of Defatted Flaxseed and Sunflower Is Affected by Heat Treatment.

    Science.gov (United States)

    Lashkari, Saman; Hymøller, Lone; Jensen, Søren Krogh

    2017-10-11

    The effect of heat treatment on biohydrogenation of linoleic acid (LA) and linolenic acid (LNA) and formation of stearic acid (SA), cis-9, trans-11 conjugated LA (CLA), trans-10, cis-12 CLA and trans-vaccenic acid (VA) was studied in in vitro incubations with diluted rumen fluid as inoculum and partly defatted flaxseed (DF) and partly defatted sunflower (DS) as test feeds. Feeds were heated in a laboratory oven at 110 °C for 0 (unheated), 45, or 90 min. Michaelis-Menten kinetics was applied for quantifying biohydrogenation rate. The DF heated for 90 min showed the lowest biohydrogenation rate of LNA and LA, indicated by the lowest Vmax value (P < 0.04 and P < 0.03, respectively). The DS heated for 45 min had the lowest biohydrogenation rate of LNA, indicated by the lowest Vmax value (P < 0.04). In conclusion, heat treatment decreased biohydrogenation of LA and LNA in DF and LNA in DS.

  20. Pre-heating of high-viscosity bulk-fill resin composites: effects on shrinkage force and monomer conversion.

    Science.gov (United States)

    Tauböck, Tobias T; Tarle, Zrinka; Marovic, Danijela; Attin, Thomas

    2015-11-01

    To investigate the influence of pre-heating of high-viscosity bulk-fill composite materials on their degree of conversion and shrinkage force formation. Four bulk-fill composite materials (Tetric EvoCeram Bulk Fill-TECBF, x-tra fil-XF, QuixFil-QF, SonicFill-SF) and one conventional nano-hybrid resin composite (Tetric EvoCeram-TEC) were used. The test materials were either kept at room temperature or pre-heated to 68°C by means of a commercial heating device, before being photoactivated with a LED curing unit for 20s at 1170mW/cm(2). Shrinkage forces (n=5) of 1.5-mm-thick specimens were recorded in real-time for 15min inside a temperature-controlled chamber at 25°C (simulating intraoral temperature after rubber dam application) with a custom-made stress analyzer. Degree of conversion (n=5) was determined at the bottom of equally thick (1.5mm) specimens using Fourier transform infrared spectroscopy. Data were analyzed with Student's t-test, ANOVA and Tukey's HSD post-hoc test (α=0.05). Composite pre-heating significantly increased the degree of conversion of TECBF, but had no effect on monomer conversion of the other materials investigated. For each of the test materials, pre-heated composite generated significantly lower shrinkage forces than room-temperature composite. At both temperature levels, TECBF created the significantly highest shrinkage forces, and QF caused significantly higher shrinkage forces than both XF and TEC. Both the composite material and the pre-cure temperature affect shrinkage force formation. Pre-heating of bulk-fill and conventional restorative composites prior to photoactivation decreases polymerization-induced shrinkage forces without compromising the degree of conversion. Composite pre-heating significantly reduces shrinkage force formation of high-viscosity bulk-fill and conventional resin composites, while maintaining or increasing the degree of monomer conversion, dependent upon the specific composite material used. Copyright

  1. Heat Treatment of Cr- and Cr-V ledeburitic tool steels

    Directory of Open Access Journals (Sweden)

    Peter Jurči

    2014-11-01

    Full Text Available Cr- and Cr-V ledeburitic cold work tool steels belong to the most important tool materials for large series manufacturing. To enable high production stability, the tools must be heat treated before use. This overview paper brings a comprehensive study on the heat treatment of these materials, starting from the soft annealing and finishing with the tempering. Also, it describes the impact of any step of the heat treatment on the most important structural and mechanical characteristics, like the hardness, the toughness and the wear resistance. The widely used AIS D2- steel (conventionally manufactured and Vanadis 6 (PM are used as examples in most cases.

  2. Aging of iron (hydr)oxides by heat treatment and effects on heavy metal binding

    DEFF Research Database (Denmark)

    Sørensen, Mette Abildgaard; Starckpoole, M. M.; Frenkel, A. I.

    2000-01-01

    their transformations caused by heat treatment prior to disposal or aging at a proper disposal site. The transformations were investigated by XRD, SEM, XANES, EXAFS, surface area measurements, pH static leaching tests, and extractions with oxalate and weak hydrochloric acid. It was found that at 600 and 900 °C the iron...... oxides were transformed to hematite, which had a greater thermodynamic stability but less surface area than the initial products. Heat treatment also caused some volatilization of heavy metals (most notably, Hg). Leaching with water at pH 9 (L/S 10, 24 h) and weak acid extraction showed that heat...

  3. Effect of heat treatments in the silicon eutectic crystal evolution in Al-Si alloys

    Energy Technology Data Exchange (ETDEWEB)

    Forn, A.; Baile, M.T.; Martin, E.; Ruperez, E. [Light Alloys and Surface Treatments Design Centre (CDAL), Univ. Politecnica de Catalunya, Vilanova I la Geltru (Spain)

    2005-07-01

    This paper describes the heat treatment effect on the eutectic silicon evolution in the A357 alloy, obtained by semisolid forming process (SSM). The coarsening rate of the silicon was determined by image analysis technique in specimens from rheocasting ingots and thixocasting components. The study was realized in the temperature range from 450 to 550 C by applying heating times between 1 and 24 hours. The results show that during the heat treatment the coarsening and sphereodization of the silicon particles is produced and the fragmentation stages, which are observed in conventional alloys, do not appear. Kinetic silicon growth has been adjusted to the Oswald's ripening equation. (orig.)

  4. Effect of alkali and heat treatments for bioactivity of TiO{sub 2} nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seo young, E-mail: mast6269@nate.com [Dept. of Dental Biomaterials and Institute of Bio degradable material, Institute of Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Kim, Yu kyoung, E-mail: yk0830@naver.com [Dept. of Dental Biomaterials and Institute of Bio degradable material, Institute of Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Park, Il song, E-mail: ilsong@jbnu.ac.kr [Division of Advanced Materials Engineering, Research Center for Advanced Materials Development and Institute of Biodegradable Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Jin, Guang chun, E-mail: jingc88@126.com [Oral Medical College, Beihua University, Jilin City 132013 (China); Bae, Tae sung, E-mail: bts@jbnu.ac.kr [Dept. of Dental Biomaterials and Institute of Bio degradable material, Institute of Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Lee, Min ho, E-mail: mh@jbnu.ac.kr [Dept. of Dental Biomaterials and Institute of Bio degradable material, Institute of Oral Bioscience and BK21 plus project, School of Dentistry, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of)

    2014-12-01

    Highlights: • TiO{sub 2} nanotubes formed via anodization were treated by alkali and heat. • The surface roughness was increased after alkali treatment (p < 0.05). • After alkali and heat treatment, the wettability was better than before treatment. • Alkali treated TiO{sub 2} nanotubes were shown higher HAp formation in SBF. • Heat treatment affected on the attachment of cells for alkali treated nanotubes. - Abstract: In this study, for improving the bioactivity of titanium used as an implant material, alkali and heat treatments were carried out after formation of the nanotubes via anodization. Nanotubes with uniform length, diameter, and thickness were formed by anodization. The alkali and heat-treated TiO{sub 2} nanotubes were covered with the complex network structure, and the Na compound was generated on the surface of the specimens. In addition, after 5 and 10 days of immersion in the SBF, the crystallized OCP and HAp phase was significantly increased on the surface of the alkali-treated TiO{sub 2} nanotubes (PNA) and alkali and heat-treated TiO{sub 2} nanotubes (PNAH) groups. Cell proliferation was decreased due to the formation of amorphous sodium titanate (Na{sub 2}TiO{sub 3}) layer on the surface of the PNA group. However, anatase and crystalline sodium titanate were formed on the surface of the PNAH group after heat treatment at 550 °C, and cell proliferation was improved. Thus, PNA group had higher HAp forming ability in the simulated body fluid. Additional heat treatment affected on enhancement of the bioactivity and the attachment of osteoblasts for PNA group.

  5. First order reversal curve analysis on NdFeB nanocomposite ribbons subjected to Joule heating treatments

    Energy Technology Data Exchange (ETDEWEB)

    Pampillo, L.G. [INTECIN-Instituto de Tecnologias y ciencias de la Ingenieria ' Hilario Fernandez Long' (UBA-CONICET), Facultad de Ingenieria, Paseo Colon 850 (C1063ACV), C. A. B. A. (Argentina); Saccone, F.D., E-mail: fsaccone@fi.uba.ar [INTECIN-Instituto de Tecnologias y ciencias de la Ingenieria ' Hilario Fernandez Long' (UBA-CONICET), Facultad de Ingenieria, Paseo Colon 850 (C1063ACV), C. A. B. A. (Argentina); Knobel, M. [Instituto de Fisica Gleb Wataghin-Departamento de Fisica de Materia Condensada-Universidade Estadual de Campinas, Cidade Universitaria Zeferino Vaz, Barao Geraldo 13083-970, Campinas, Sao Paulo (Brazil); Sirkin, H.R.M. [INTECIN-Instituto de Tecnologias y ciencias de la Ingenieria ' Hilario Fernandez Long' (UBA-CONICET), Facultad de Ingenieria, Paseo Colon 850 (C1063ACV), C. A. B. A. (Argentina)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Nd-lean amorphous precursors subjected to Joule heating. Black-Right-Pointing-Pointer Exchange-spring magnets. Black-Right-Pointing-Pointer FORC diagrams of irreversible switching fields. Black-Right-Pointing-Pointer This last techniques helped us to verify the optimized treatments conditions. - Abstract: Amorphous precursors with composition Nd{sub 4.5}Fe{sub 72-x}Co{sub 3+x}Cr{sub 2}Al{sub 1}B{sub 17.5} (x = 0, 2, 7, 12) were thermally treated by the Joule heating technique with a linearly varying electrical current. The crystallization kinetics was followed by monitoring the resistance of the ribbons during the heating up to the final applied current. Crystallized nanostructured phases coexist with an amorphous matrix, as it was observed by means of Moessbauer Spectroscopy and X-ray diffraction. The irreversible magnetic response of the Joule heated ribbons was analyzed by the First Order Reversal Curves (FORC) diagram technique. For the optimal treatments, associated with the higher maximum energy products for each sample composition, it was found that the main interaction is of a strongly dipolar characteristic. Over annealed samples show a FORC diagram that gives into account of softening, due to grain growth, for those phases precipitated at the first crystallization stage. When it is measured at 20 K, the hardest magnetic sample (Fe = 72 at.%, Co = 3 at.%, I{sub final} = 0.5 A), exhibits a diagram with characteristics corresponding to dipolar interactions of soft phases. This fact is consistent with an enhancement of the exchange length due to the increase in the soft phase stiffness as it is expected at low temperatures.

  6. Influence of heat treatment on the structure and thermoelectric properties of CrSi2

    Science.gov (United States)

    Solomkin, F. Yu.; Suvorova, E. I.; Zaitsev, V. K.; Novikov, S. V.; Burkov, A. T.; Samunin, A. Yu.; Isachenko, G. N.

    2011-02-01

    Textured CrSi2 crystals obtained by heating finely dispersed constituents (Si, Cr) are studied. The use of a mixture of Cr and Si powders makes it possible to lower the CrSi2 synthesis temperature by 100 K. Crystallization conditions and post-crystallization annealing are found to influence the thermoelectric properties and composition of samples.

  7. Combined heat transfer and kinetic models to predict cooking loss during heat treatment of beef meat.

    Science.gov (United States)

    Kondjoyan, Alain; Oillic, Samuel; Portanguen, Stéphane; Gros, Jean-Bernard

    2013-10-01

    A heat transfer model was used to simulate the temperature in 3 dimensions inside the meat. This model was combined with a first-order kinetic models to predict cooking losses. Identification of the parameters of the kinetic models and first validations were performed in a water bath. Afterwards, the performance of the combined model was determined in a fan-assisted oven under different air/steam conditions. Accurate knowledge of the heat transfer coefficient values and consideration of the retraction of the meat pieces are needed for the prediction of meat temperature. This is important since the temperature at the center of the product is often used to determine the cooking time. The combined model was also able to predict cooking losses from meat pieces of different sizes and subjected to different air/steam conditions. It was found that under the studied conditions, most of the water loss comes from the juice expelled by protein denaturation and contraction and not from evaporation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. The effects of heat treatment on physical and technological ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... elasticity in bending, Janka-hardness (cross-section, parallel and perpendicular to grain), impact bending strength, tensile strength perpendicular to grain and surface roughness values decreased with increasing treatment temperature and treatment times. Increase in temperature and duration further.

  9. Surface development of a brazing alloy during heat treatment-a comparison between UHV and APXPS.

    Science.gov (United States)

    Rullik, L; Johansson, N; Bertram, F; Evertsson, J; Stenqvist, T; Lundgren, E

    2018-01-17

    In an attempt to bridge the pressure gap, APXPS was used to follow the surface development of an aluminum brazing sheet during heating in an ambient oxygen-pressure mimicking the environment of an industrial brazing furnace. The studied aluminum alloy brazing sheet is a composite material consisting of two aluminum alloy standards whose surface is covered with a native aluminum oxide film. To emphasize the necessity of studies of this system in ambient sample environments it is compared to measurements in UHV. Changes in thickness and composition of the surface oxide were followed after heating to 300 °C, 400 °C, and 500 °C. The two sets presented in this paper show that the surface development strongly depends on the environment the sample is heated in.

  10. Structural modifications of Tilia cordata wood during heat treatment investigated by FT-IR and 2D IR correlation spectroscopy

    Science.gov (United States)

    Popescu, Maria-Cristina; Froidevaux, Julien; Navi, Parviz; Popescu, Carmen-Mihaela

    2013-02-01

    It is known that heat treatment of wood combined with a low percent of relative humidity causes transformations in the chemical composition of it. The modifications and/or degradation of wood components occur by hydrolysis, oxidation, and decarboxylation reactions. The aim of this study was to give better insights on wood chemical modifications during wood heat treatment under low temperature at about 140 °C and 10% percentage of relative humidity, by infrared, principal component analysis and two dimensional infrared correlation spectroscopy. For this purpose, hardwood samples of lime (Tilia cordata) were investigated and analysed. The infrared spectra of treated samples were compared with the reference ones, the most important differences being observed in the "fingerprint" region. Due to the complexity of this region, which have contributions from all the wood constituents the chemical changes during hydro-thermal treatment were examined in detail using principal component analysis and 2D IR correlation spectroscopy. By hydro-thermal treatment of wood results the formation of acetic acid, which catalyse the hydrolysis reactions of hemicelluloses and amorphous cellulose. The cleavage of the β-O-4 linkages and splitting of the aliphatic methoxyl chains from the aromatic lignin ring was also observed. For the first treatment interval, a higher extent of carbohydrates degradation was observed, then an increase of the extent of the lignin degradation also took place.

  11. THE CHANGE OF MECHANICAL PROPERTIES IN COLD DRAWN BARS BY HEAT TREATMENT

    Directory of Open Access Journals (Sweden)

    N. Sinan KÖKSAL

    1999-02-01

    Full Text Available Manufacturing methods and the applied heat treatment are important for the properties of materials. Building safe constructions with the materials used depends on the knowledge and correct use of their properties. In this study, cold drawn bar specimens of Ç1040 are heat treated in three different temperatures (500 o C, 650 o C, 840 o C and the strength, hardness, and strain values are compared with those of untreated materials. Cold drawn bars has shown higher strength values when compared with the hot rolled bars. This is because of the type of process selected for manufacturing. By heat treatment, strain has increased, hardness and strength have decreased. It has been observed that the rate of increasing or decreasing depends on the temperature and duration of the heat treatment.

  12. Optimizing the heat treatment of Ni-based superalloy turbine discs

    Science.gov (United States)

    Furrer, D. U.; Shankar, R.; White, C.

    2003-03-01

    The heat-treatment processes for nickel-based superalloys continue to change due to the development of new alloys, new requirements, and subsequent new manufacturing facilities. Nickel-based superalloys are continuing to evolve to meet emerging applications, while new alloys are also being introduced for advanced applications. These new materials are also being optimized for numerous mechanical and physical properties, making the selection of heat-treatment parameters increasingly challenging. New processing facilities and methods are also being implemented to allow tailoring of heat-treating parameters to meet these new challenges. For example, the Ladish SuperCooler technology allows engineering and control of all aspects of the heat-treatment process for nickel-based components, resulting in never-before possible disc properties.

  13. Dry heat treatment affects wheat bran surface properties and hydration kinetics.

    Science.gov (United States)

    Jacobs, Pieter J; Hemdane, Sami; Delcour, Jan A; Courtin, Christophe M

    2016-07-15

    Heat stabilization of wheat bran aims at inactivation of enzymes which may cause rancidity and processability issues. Such treatments may however cause additional unanticipated phenomena which may affect wheat bran technological properties. In this work, the impact of toasting on wheat bran hydration capacity and hydration kinetics was studied. Hydration properties were assessed using the Enslin-Neff and drainage centrifugation water retention capacity methods, thermogravimetric analysis and contact angle goniometry, next to more traditional methods. While equilibrium hydration properties of bran were not affected by the heat treatment, the rate at which the heat treated bran hydrated was, however, very significantly reduced compared to the untreated bran. This phenomenon was found to originate from the formation of a lipid coating during the treatment rendering the bran surface hydrophobic. These insights help to understand and partially account for the modified processability of heat treated bran in food applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. UV-Heat Treatments for the Control of Foodborne Microbial Pathogens in Chicken Broth

    Directory of Open Access Journals (Sweden)

    M. Gouma

    2015-01-01

    Full Text Available This investigation established the process criteria for using UV-C light and mild heat (UV-H treatment to inactivate 5-Log10 cycles (performance criterion of common foodborne pathogen populations, Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus, when inoculated in chicken broth. To define the target microorganism and the proper UV-H treatment conditions (including UV dose, treatment time, and temperature that would achieve the stated performance criterion, mathematical equations based on Geeraerd’s model were developed for each microorganism. For the sake of comparison, inactivation equations for heat treatments were also performed on the same chicken broth and for the same microorganisms. L. monocytogenes was the most UV-H resistant microorganism at all temperatures, requiring a UV dose between 6.10 J/mL (5.6 min and 2.26 J/mL (2.09 min to achieve 5-Log10 reductions. In comparison with UV treatments at room temperatures, the combination of UV and mild heat allowed both the UV dose and treatment time to be reduced by 30% and 63% at 55°C and 60°C, respectively. Compared to heat treatments, the UV-H process reduced the heating time for 5-Log10 reductions of all the investigated microorganisms in chicken broth from 20-fold to 2-fold when the operating temperature varied from 53 to 60°C.

  15. Study on Spheroidization and Related Heat Treatments of Medium Carbon Alloy Steels

    Directory of Open Access Journals (Sweden)

    Harisha S. R.

    2018-01-01

    Full Text Available The importance of medium carbon steels as engineering materials is reflected by the fact that out of the vast majority of engineering grade ferrous alloys available and used in the market today, a large proportion of them are from the family of medium carbon steels. Typically medium carbon steels have a carbon range of 0.25 to 0.65% by weight, and a manganese content ranging from 0.060 to 1.65% by weight. Medium carbon steels are more resistive to cutting, welding and forming as compared to low carbon steels. From the last two decades a number of research scholars reported the use of verity of heat treatments to tailor the properties of medium carbon steels. Spheroidizing is the novel industrial heat treatment employed to improve formability and machinability of medium/high carbon low alloy steels. This exclusive study covers procedure, the effects and possible outcomes of various heat treatments on medium carbon steels. In the present work, other related heat treatments like annealing and special treatments for property alterations which serve as pretreatments for spheroidizing are also reviewed. Medium carbon steels with property alterations by various heat treatment processes are finding increased responsiveness in transportation, aerospace, space, underwater along with other variegated fields. Improved tribological and mechanical properties consisting of impact resistance, stiffness, abrasion and strength are the main reasons for the increased attention of these steels in various industries. In the present scenario for the consolidation of important aspects of various heat treatments and effects on mechanical properties of medium carbons steel, a review of different research papers has been attempted. This review may be used as a guide to provide practical data for heat treatment industry, especially as a tool to enhance workability and tool life.

  16. Periconceptional Heat Stress of Holstein Dams Is Associated with Differences in Daughter Milk Production and Composition during Multiple Lactations

    OpenAIRE

    Brown, Britni M.; Stallings, Jon W.; Clay, John S.; Rhoads, Michelle L.

    2015-01-01

    Heat stress at the time of conception affects the subsequent milk production of primiparous Holstein cows; however, it is unknown whether these effects are maintained across multiple lactations. Therefore, the objective of the current study was to examine the relationship between periconceptional heat stress and measurements of milk production and composition in cows retained within a herd for multiple lactations. National Dairy Herd Improvement Association data was obtained from Dairy Record...

  17. Influence of the heat treatment on the microstructure and properties of austenitic cast steel

    Directory of Open Access Journals (Sweden)

    P. Bała

    2010-07-01

    Full Text Available Exploitation investigations of a centrifugally cast pipe of austenitic cast steel indicated a significant influence of its microstructure on functional properties. Determination of the possibility of forming the microstructure and properties of the investigated cast steel by heat treatments was the aim of the presented paper. According to the Standard ASTM A 297, material from which the pipe was made is determined as HF type cast steel. The solution heat treatment from a temperature of 1080 °C was performed and followed by the microstructure observations and hardness measurements. It was found, that the solution heat treatment from this temperature will notsignificantly improve the material strength properties. However, it will visibly influence its fracture toughness. An influence of agingperformed after the solution heat treatment on microstructure and hardness was also investigated. Cast steel was aged for 1 hour at 600°C (solution heat treatment from 1080 °C. On the basis of the obtained results it was found, that the solution heat treatment temperature should be the maximum permissible by the Standard i.e. 1150 °C. Heating the supersaturated material (from 1150 °C even toa temperature of 600 °C should not cause the carbide precipitation in a form of the continuous network in grain boundaries, which woulddecrease fracture toughness of the investigated cast steel. Due to fracture toughness a service exposure of this material should not exceed 600 °C. The permissible service exposure up to 900 °C, given for this material in the Standard, is correct only on account of heat and high temperature creep resistance but not fracture toughness.

  18. Acute effects of dehydration on sweat composition in men during prolonged exercise in the heat.

    Science.gov (United States)

    Morgan, R M; Patterson, M J; Nimmo, M A

    2004-09-01

    To determine whether acute exercise-heat-induced dehydration affects sweat composition, eight males cycled for 2 h at 39.5 +/- 1.6% VO2peak on two separate occasions in a hot-humid environment (38.0 +/- 0.0 degrees C, 60.0 +/- 0.1% relative humidity). During exercise, subjects ingested either no fluid (dehydration) or a 20 mmol L(-1) sodium chloride solution (euhydration). The volume of solution, calculated from whole-body sweat loss and determined in a familiarization trial, was ingested at 0 min and every 15 min thereafter. Venous blood was collected at 0, 60 and 120 min of exercise and sweat was aspirated from a patch located on the dominant forearm at 120 min. Following the 2-h cycling exercise, sweat [Na+] and [Cl-] was greater (P sweat [Na+] and [Cl-] which was potentially related to greater extracellular fluid [Na+], plasma aldosterone or sympathetic nervous activity.

  19. Exchange bias in sputtered FeNi/FeMn systems: Effect of short low-temperature heat treatments

    Energy Technology Data Exchange (ETDEWEB)

    Savin, Peter, E-mail: peter.savin@urfu.ru [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Guzmán, Jorge [Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain); Lepalovskij, Vladimir [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Svalov, Andrey; Kurlyandskaya, Galina [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Departamento de Electricidad y Electrónica, Universidad del País Vasco (UPV/EHU), 48940 Leioa, Vizcaya (Spain); Asenjo, Agustina [Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain); Vas’kovskiy, Vladimir [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Vazquez, Manuel [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain)

    2016-03-15

    Short (5 min) post-deposition thermal treatments under magnetic field at low temperature (up to 200 °C) performed in exchange-coupled FeNi(40 nm)/FeMn(20 nm) bilayer thin films prepared by magnetron sputtering are shown to be effective to significantly modify their exchange field (from around 40 Oe down to 27 Oe) between FeNi and FeMn layers. A similar exchange field decrease was observed for the first deposited FeNi layer of the FeNi(40 nm)/FeMn(20 nm)/FeNi(40 nm) trilayer films after the same thermal treatments. The exchange field value for the second FeNi layer was not substantially changed. The X-ray diffraction patterns indicates that such a heat treatment has no effect on the grain size and crystalline texture of the films, while atomic force microscope studies reveal an increase of the surface roughness after the treatment which is more noticeable in the case of the trilayer film. Analysis of the experimental results leads us to conclude that the variations of the exchange field after heat treatment are likely caused by a modification of interfacial roughness and/or interfacial magnetic structure, but unlikely by the changes in the microstructure and/or changes of composition of the antiferromagnetic FeMn layer. - Highlights: • FeNi/FeMn bilayers and FeNi/FeMn/FeNi trilayers were prepared by magnetron sputtering. • Post-deposition heat treatments at the temperatures below 200 °C during 5 min were made. • Annealing reduces the exchange field for the first FeNi layer in trilayers. • The exchange field value for the second FeNi layer was not substantially changed. • Exchange field changes are most likely caused by a modification of interface roughness.

  20. Studies on Adhesive Wear Characteristics of Heat Treated Aluminium LM25/AlB2 Composites

    Directory of Open Access Journals (Sweden)

    K.S. Arunagiri

    2016-09-01

    Full Text Available The main aim of this study was to determine the adhesive wear characteristics of heat treated LM 25/AlB2 metal matrix composites fabricated using liquid metallurgy route. The composite samples were solutionized at 525 °C and then water quenched. Aging was done at different temperatures (160 °C, 175 °C, 200 °C and 250 °C for different aging time (4 hrs, 6 hrs, and 8 hrs. Brinell hardness tester was used to evaluate the hardness of all aged samples and maximum hardness (82 HRB was observed in the sample aged for 6 hours at 250°C . Those heat treated specimens were taken for further experimentation on wear characteristics. Pin-on-disc tribometer was used to analyse the dry sliding wear characteristics and the experiments were conducted based on Taguchi’s L16 orthogonal array by varying the process parameters of load (10 N, 20 N, 30 N and 40 N, sliding distance (400 m, 800 m, 1200 m and 1600 m and sliding velocity (1 m/s, 2 m/s, 3 m/s and 4 m/s for four levels. The dependence of wear rate on various parameters was found out using ANOVA and S/N ratio. The experimental result shows that sliding velocity (56.6 % influences more on wear rate followed by load (23.09 % and sliding distance (6.02 %. The regression equation was developed and the confirmatory result shows less error. The worn surfaces were analysed using Scanning Electron Microscope and severe delamination at the sliding velocity of 1m/s was found.

  1. 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)

  2. Welding of 3D-printed carbon nanotube-polymer composites by locally induced microwave heating.

    Science.gov (United States)

    Sweeney, Charles B; Lackey, Blake A; Pospisil, Martin J; Achee, Thomas C; Hicks, Victoria K; Moran, Aaron G; Teipel, Blake R; Saed, Mohammad A; Green, Micah J

    2017-06-01

    Additive manufacturing through material extrusion, often termed three-dimensional (3D) printing, is a burgeoning method for manufacturing thermoplastic components. However, a key obstacle facing 3D-printed plastic parts in engineering applications is the weak weld between successive filament traces, which often leads to delamination and mechanical failure. This is the chief obstacle to the use of thermoplastic additive manufacturing. We report a novel concept for welding 3D-printed thermoplastic interfaces using intense localized heating of carbon nanotubes (CNTs) by microwave irradiation. The microwave heating of the CNT-polymer composites is a function of CNT percolation, as shown through in situ infrared imaging and simulation. We apply CNT-loaded coatings to a 3D printer filament; after printing, microwave irradiation is shown to improve the weld fracture strength by 275%. These remarkable results open up entirely new design spaces for additive manufacturing and also yield new insight into the coupling between dielectric properties and radio frequency field response for nanomaterial networks.

  3. Surface treatment of CFRP composites using femtosecond laser radiation

    Science.gov (United States)

    Oliveira, V.; Sharma, S. P.; de Moura, M. F. S. F.; Moreira, R. D. F.; Vilar, R.

    2017-07-01

    In the present work, we investigate the surface treatment of carbon fiber-reinforced polymer (CFRP) composites by laser ablation with femtosecond laser radiation. For this purpose, unidirectional carbon fiber-reinforced epoxy matrix composites were treated with femtosecond laser pulses of 1024 nm wavelength and 550 fs duration. Laser tracks were inscribed on the material surface using pulse energies and scanning speeds in the range 0.1-0.5 mJ and 0.1-5 mm/s, respectively. The morphology of the laser treated surfaces was investigated by field emission scanning electron microscopy. We show that, by using the appropriate processing parameters, a selective removal of the epoxy resin can be achieved, leaving the carbon fibers exposed. In addition, sub-micron laser induced periodic surface structures (LIPSS) are created on the carbon fibers surface, which may be potentially beneficial for the improvement of the fiber to matrix adhesion in adhesive bonds between CFRP parts.

  4. Effect of friction stir welding and post-weld heat treatment on a nanostructured ferritic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Mazumder, B., E-mail: mazumderb@ornl.gov [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Yu, X.; Edmondson, P.D.; Parish, C.M. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Miller, M.K. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Meyer, H.M.; Feng, Z. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

    2016-02-15

    Nanostructured ferritic alloys (NFAs) are new generation materials for use in high temperature energy systems, such as nuclear fission or fusion reactors. However, joining these materials is a concern, as their unique microstructure is destroyed by traditional liquid-state welding methods. The microstructural evolution of a friction stir welded 14YWT NFA was investigated by atom probe tomography, before and after a post-weld heat treatment (PWHT) at 1123K. The particle size, number density, elemental composition, and morphology of the titanium-yttrium-oxygen-enriched nanoclusters (NCs) in the stir and thermally-affected zones were studied and compared with the base metal. No statistical difference in the size of the NCs was observed in any of these conditions. After the PWHT, increases in the number density and the oxygen enrichment in the NCs were observed. Therefore, these new results provide additional supporting evidence that friction stir welding appears to be a viable joining technique for NFAs, as the microstructural parameters of the NCs are not strongly affected, in contrast to traditional welding techniques.

  5. Magnetic properties of doped Mn-Ga alloys made by mechanical milling and heat treatment

    Directory of Open Access Journals (Sweden)

    Daniel R. Brown

    2016-05-01

    Full Text Available Mn-Ga alloys have shown hard magnetic properties, even though these alloys contain no rare-earth metals. However, much work is needed before rare-earth magnets can be replaced. We have examined the magnetic properties of bulk alloys made with partial replacement of both the Mn and Ga elements in the Mn0.8Ga0.2 system. Bulk samples of Mn-Ga-Bi, Mn-Ga-Al, Mn-Fe-Ga and Mn-(FeB-Ga alloys were fabricated and studied using mechanically milling and heat treatments while altering the atomic percentage of the third element between 2.5 and 20 at%. The ternary alloy exhibits all hard magnetic properties at room temperature with large coercivity. Annealed Mn-Ga-X bulk composites exhibit high coercivities up to 16.6 kOe and remanence up to 9.8 emu/g, that is increased by 115% over the binary system.

  6. Magnetic properties of doped Mn-Ga alloys made by mechanical milling and heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Daniel R. [Department of Material Science and Engineering, Florida State University, Tallahassee, FL 32304 (United States); National High Magnetic Field Laboratory, Tallahassee, FL 32310 (United States); Han, Ke; Niu, Rongmei [National High Magnetic Field Laboratory, Tallahassee, FL 32310 (United States); Siegrist, Theo; Besara, Tiglet [Department of Material Science and Engineering, Florida State University, Tallahassee, FL 32304 (United States); Department of Chemical Engineering, Florida Agricultural and Mechanical University-Florida State University, Tallahassee, FL 32304 (United States)

    2016-05-15

    Mn-Ga alloys have shown hard magnetic properties, even though these alloys contain no rare-earth metals. However, much work is needed before rare-earth magnets can be replaced. We have examined the magnetic properties of bulk alloys made with partial replacement of both the Mn and Ga elements in the Mn{sub 0.8}Ga{sub 0.2} system. Bulk samples of Mn-Ga-Bi, Mn-Ga-Al, Mn-Fe-Ga and Mn-(FeB)-Ga alloys were fabricated and studied using mechanically milling and heat treatments while altering the atomic percentage of the third element between 2.5 and 20 at%. The ternary alloy exhibits all hard magnetic properties at room temperature with large coercivity. Annealed Mn-Ga-X bulk composites exhibit high coercivities up to 16.6 kOe and remanence up to 9.8 emu/g, that is increased by 115% over the binary system.

  7. Effect of heat treatment and packaging systems on the stability of fish sausage

    Directory of Open Access Journals (Sweden)

    Bruna Rafaela Dallabona

    2013-12-01

    Full Text Available The purpose of this study was to evaluate the physicochemical and microbiological stability of sausages produced from mechanically separated fish meat (MSM obtained from Nile tilapia filleting residues. Different heat treatments (pasteurization or smoking and packaging systems (conventional or vacuum were used. The sausages were characterized for chemical composition, weight loss, water activity, instrumental texture and sensorial analysis. Additionally, microbiological analysis, instrumental color, pH, thiobarbituric acid reactive substances (TBARS and total volatile base nitrogen (TVB-N were assessed during storage. No presence of Escherichia coli, Salmonella sp. or coagulase-positive Staphylococcus was detected; however, the psychrotrophic count in pasteurized sausages exceeded the limits allowed for consumption. pH and lipid oxidation speed (TBARS values were reduced when vacuum packaging was used. Volatile nitrogenous bases remained virtually constant during the storage period, and higher values were observed in smoked products. Pasteurized sausages remain stable for 10 and 15 days in conventional and vacuum packages, respectively, and smoked sausages remain stable for 25 and 45 days in conventional and vacuum packages, respectively.

  8. New Approach to Simulation of Heat State of Compartments from Lattice Composite Shells for Space Engineering Products

    Directory of Open Access Journals (Sweden)

    Razin Alexander F.

    2017-01-01

    Full Text Available A new approach to the simulation of the heat state of the compartment of lattice polymer composite materials (PCM, not providing for the use of known commercial software packages, has been proposed. The simulation has been performed using the PCM interstage of the Proton rocket as an example with due account of aerodynamic heating, solar radiation and acting of jets of auxiliary propulsion units. At the first stage of numerical analysis, a problem of unsteady heat conduction in the system “skin-air gap-heat insulation” has been solved. An effect of changing a pressure inside a compartment on thermal conductivity of heat insulation was taken into account. The effective thermal conductivity in gaps was used. An effect of a temperature of equipment on a value of radiant heat flux was also taken into account. At the second stage, the heat state of the system “skin-rib” was analyzed. A mathematical model in the form of a system of nonlinear equations for heat balance of control elements on which a rib and a skin section were partitioned, including an information about a temperature of heat insulation received at the first stage of the simulation, was used.

  9. Susceptibility of Plodia interpunctella (Lepidoptera: Pyralidae) developmental stages to high temperatures used during structural heat treatments.

    Science.gov (United States)

    Mahroof, R; Subramanyam, B

    2006-12-01

    Heating the ambient air of a whole, or a portion of a food-processing facility to 50 to 60 degrees C and maintaining these elevated temperatures for 24 to 36 h, is an old technology, referred to as heat treatment. There is renewed interest in adopting heat treatments around the world as a viable insect control alternative to fumigation with methyl bromide. There is limited published information on responses of the Indian meal moth, Plodia interpunctella (Hübner), exposed to elevated temperatures typically used during heat treatments. Time-mortality relationships were determined for eggs, fifth-instars (wandering-phase larvae), pupae, and adults of P. interpunctella exposed to five constant temperatures between 44 and 52 degrees C. Mortality of each stage increased with increasing temperature and exposure time. In general, fifth-instars were the most heat-tolerant stage at all temperatures tested. Exposure for a minimum of 34 min at 50 degrees C was required to kill 99% of the fifth-instars. It is proposed that heat treatments aimed at controlling fifth-instars should be able to control all other stages of P. interpunctella.

  10. Increased prevalence of Dirofilaria immitis antigen in canine samples after heat treatment.

    Science.gov (United States)

    Velasquez, Luisa; Blagburn, Byron L; Duncan-Decoq, Rebecca; Johnson, Eileen M; Allen, Kelly E; Meinkoth, James; Gruntmeir, Jeff; Little, Susan E

    2014-11-15

    Canine serum samples may contain factors that prevent detection of antigen of Dirofilaria immitis on commercial assays, precluding accurate diagnosis. To determine the degree to which the presence of blocking antibodies or other inhibitors of antigen detection may interfere with our ability to detect circulating antigen in canine samples, archived plasma and serum samples (n=165) collected from dogs in animal shelters were tested for D. immitis antigen before and after heat treatment. Negative samples were also evaluated for their ability to block detection of D. immitis antigen in a sample from a positive dog. All 165 samples were negative prior to heating, but 11/154 (7.1%) became positive after heat treatment, a conversion that was documented and quantified on spectrophotometric plate assays, and 7/165 (4.2%) samples decreased detection of antigen when mixed with a known positive sample, suggesting some blocking ability was present. An additional 103 plasma and serum samples that tested positive prior to heating also were evaluated; the optical density of 14/101 (13.9%) increased by ≥50%, and one sample by as much as 15-fold, after heat treatment. Our results suggest that canine serum and plasma samples from dogs in the southeastern United States can contain inhibitors of D. immitis antigen detection, and that prevalence estimates of heartworm infection based on these assays would benefit from heat treatment of samples prior to testing. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. A Study on Infrared Local Heat Treatment for AA5083 to Improve Formability and Automotive Part Forming

    Science.gov (United States)

    Lee, Eun-Ho; Yang, Dong-Yol; Ko, SeJin

    2017-09-01

    Automotive industries are increasingly employing aluminum alloys for auto parts to reduce vehicle weight. However, the low formability of aluminum alloys has been an obstacle to their application. To resolve the formability problem, some studies involving heat treatments under laboratory conditions have been reported. However, for industrial applications, the heat treatment sequence, heating energy efficiency, and a commercial part test should be studied. This work shows an infrared (IR) local heat treatment, heating only small areas where the heat treatment is required, for an aluminum alloy to improve the formability with a reduction of heating energy. The experiment shows that the formability drastically increases when the aluminum alloy is heat treated between two forming stages, referred to as intermediate heat treatment. The microstructures of the test pieces are evaluated to identify the cause of the increase in the formability. For an industrial application, an aluminum tailgate, which cannot be manufactured without heat treatment, was successfully manufactured by the IR local heat treatment with a reduction of energy. A simulation was also conducted with a stress-based forming limit diagram, which is not affected by the strain path and heat treatment histories. The simulation gives a good prediction of the formability improvement.

  12. Modelling of volumetric composition and mechanical properties of unidirectional hemp/epoxy composites - Effect of enzymatic fibre treatment

    DEFF Research Database (Denmark)

    Liu, Ming; Thygesen, Anders; Meyer, Anne S.

    2016-01-01

    The objective of the present study is to assess the effect of enzymatic fibre treatments on the fibre performance in unidirectional hemp/epoxy composites by modelling the volumetric composition and mechanical properties of the composites. It is shown that the applied models can well predict...... the changes in volumetric composition and mechanical properties of the composites when differently treated hemp fibres are used. The decrease in the fibre correlated porosity factor with the enzymatic fibre treatments shows that the removal of pectin by pectinolytic enzymes results in a better fibre...

  13. Application of C/C composites to the combustion chamber of rocket engines. Part 1: Heating tests of C/C composites with high temperature combustion gases

    Science.gov (United States)

    Tadano, Makoto; Sato, Masahiro; Kuroda, Yukio; Kusaka, Kazuo; Ueda, Shuichi; Suemitsu, Takeshi; Hasegawa, Satoshi; Kude, Yukinori

    1995-04-01

    Carbon fiber reinforced carbon composite (C/C composite) has various superior properties, such as high specific strength, specific modulus, and fracture strength at high temperatures of more than 1800 K. Therefore, C/C composite is expected to be useful for many structural applications, such as combustion chambers of rocket engines and nose-cones of space-planes, but C/C composite lacks oxidation resistivity in high temperature environments. To meet the lifespan requirement for thermal barrier coatings, a ceramic coating has been employed in the hot-gas side wall. However, the main drawback to the use of C/C composite is the tendency for delamination to occur between the coating layer on the hot-gas side and the base materials on the cooling side during repeated thermal heating loads. To improve the thermal properties of the thermal barrier coating, five different types of 30-mm diameter C/C composite specimens constructed with functionally gradient materials (FGM's) and a modified matrix coating layer were fabricated. In this test, these specimens were exposed to the combustion gases of the rocket engine using nitrogen tetroxide (NTO) / monomethyl hydrazine (MMH) to evaluate the properties of thermal and erosive resistance on the thermal barrier coating after the heating test. It was observed that modified matrix and coating with FGM's are effective in improving the thermal properties of C/C composite.

  14. Effects of local heat and cold treatment on surface and articular temperature of arthritic knees

    NARCIS (Netherlands)

    Oosterveld, Frederikus G.J.; Rasker, Hans J.

    1994-01-01

    Objective: To evaluate and compare the effects of locally applied heat and cold treatments on skin and intraarticular temperature in patients with arthritis. Methods. Thirty-nine patients with arthritis of the knee were divided at random into 4 treatment groups (ice chips, nitrogen cold air,

  15. Effects of heating treatment on some of the physical properties of ...

    African Journals Online (AJOL)

    Once heat treatment was conducted, four types of varnish layers (cellulose lacquer, synthetic varnish, polyurethane varnish and water based varnish) were applied to the materials. After the treatments application, color, brightness and surface roughness of varnish film layers of the treated woods were measured. The effects ...

  16. Carotenoids, Fatty Acid Composition and Heat Stability of Supercritical Carbon Dioxide-Extracted-Oleoresins

    Science.gov (United States)

    Longo, Cristiano; Leo, Lucia; Leone, Antonella

    2012-01-01

    The risk of chronic diseases has been shown to be inversely related to tomato intake and the lycopene levels in serum and tissue. Cis-isomers represent approximately 50%–80% of serum lycopene, while dietary lycopene maintains the isomeric ratio present in the plant sources with about 95% of all-trans-lycopene. Supercritical CO2 extraction (S-CO2) has been extensively developed to extract lycopene from tomato and tomato processing wastes, for food or pharmaceutical industries, also by using additional plant sources as co-matrices. We compared two S-CO2-extracted oleoresins (from tomato and tomato/hazelnut matrices), which showed an oil-solid bi-phasic appearance, a higher cis-lycopene content, and enhanced antioxidant ability compared with the traditional solvent extracts. Heat-treating, in the range of 60–100 °C, led to changes in the lycopene isomeric composition and to enhanced antioxidant activity in both types of oleoresins. The greater stability has been related to peculiar lycopene isomer composition and to the lipid environment. The results indicate these oleoresins are a good source of potentially healthful lycopene. PMID:22605975

  17. Heuristic algorithms for scheduling heat-treatment furnaces of steel ...

    Indian Academy of Sciences (India)

    treatment furnaces in a steel-casting foundry, a special problem of batch processor scheduling, ... production management is to maximize throughput and reduce flow time and WIP. This motivated the choice of ..... A computational experiment is appropriate in order to provide a perspective on the relative effectiveness of any ...

  18. Modification of the original color of the Eucalyptus grandis wood by heat treatments

    Directory of Open Access Journals (Sweden)

    Rosilei Aparecida Garcia

    2014-09-01

    Full Text Available The objective of this study was to determine the modification of original color of Eucalyptus grandis Hill ex. Maiden wood after heat-treatment. Wood samples were heat-treated under different temperatures (180, 200, 215 and 230ºC and time conditions (15 minutes, 2 and 4 hours. Color analysis were performed on the CIE L*a*b* system by using a Color Eye XTH-X-Rite 200d spectrophotometer. All heat treatments promoted an alteration of the original color of wood. Heat-treated woods presented lower L* (lightness values than untreated wood (control, characterizing the wood darkness, mainly for more severe conditions of temperature and time. Chromatic coordinates (a* and b* showed different behaviors depending on the temperature-time combination. The modification of the original color of the wood allowed the creation of new color patterns, which can add greater value to the studied wood.

  19. Manufacturing of tailored tubes with a process integrated heat treatment

    Science.gov (United States)

    Hordych, Illia; Boiarkin, Viacheslav; Rodman, Dmytro; Nürnberger, Florian

    2017-10-01

    The usage of work-pieces with tailored properties allows for reducing costs and materials. One example are tailored tubes that can be used as end parts e.g. in the automotive industry or in domestic applications as well as semi-finished products for subsequent controlled deformation processes. An innovative technology to manufacture tubes is roll forming with a subsequent inductive heating and adapted quenching to obtain tailored properties in the longitudinal direction. This processing offers a great potential for the production of tubes with a wide range of properties, although this novel approach still requires a suited process design. Based on experimental data, a process simulation is being developed. The simulation shall be suitable for a virtual design of the tubes and allows for gaining a deeper understanding of the required processing. The model proposed shall predict microstructural and mechanical tube properties by considering process parameters, different geometries, batch-related influences etc. A validation is carried out using experimental data of tubes manufactured from various steel grades.

  20. Staphylococcus aureus dry-surface biofilms are more resistant to heat treatment than traditional hydrated biofilms.

    Science.gov (United States)

    Almatroudi, A; Tahir, S; Hu, H; Chowdhury, D; Gosbell, I B; Jensen, S O; Whiteley, G S; Deva, A K; Glasbey, T; Vickery, K

    2018-02-01

    The importance of biofilms to clinical practice is being increasingly realized. Biofilm tolerance to antibiotics is well described but limited work has been conducted on the efficacy of heat disinfection and sterilization against biofilms. To test the susceptibility of planktonic, hydrated biofilm and dry-surface biofilm forms of Staphylococcus aureus, to dry-heat and wet-heat treatments. S. aureus was grown as both hydrated biofilm and dry-surface biofilm in the CDC biofilm generator. Biofilm was subjected to a range of temperatures in a hot-air oven (dry heat), water bath or autoclave (wet heat). Dry-surface biofilms remained culture positive even when treated with the harshest dry-heat condition of 100°C for 60min. Following autoclaving samples were culture negative but 62-74% of bacteria in dry-surface biofilms remained alive as demonstrated by live/dead staining and confocal microscopy. Dry-surface biofilms subjected to autoclaving at 121°C for up to 30min recovered and released planktonic cells. Recovery did not occur following autoclaving for longer or at 134°C, at least during the time-period tested. Hydrated biofilm recovered following dry-heat treatment up to 100°C for 10min but failed to recover following autoclaving despite the presence of 43-60% live cells as demonstrated by live/dead staining. S. aureus dry-surface biofilms are less susceptible to killing by dry heat and steam autoclaving than hydrated biofilms, which are less susceptible to heat treatment than planktonic suspensions. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  1. Effect of different finishing: polishing systems on the surface roughness of two heat-treated composite resins

    Directory of Open Access Journals (Sweden)

    Gabrielle Ribeiro Lima

    2011-01-01

    Full Text Available The aim of this study was to compare the surface roughness achieved by different finishing/polishing systems on two composite resins for direct use after thermic treatment. The specimens (n = 40 per group (G; G1 = Filtek™ P60; G2 = Fill Magic® were set up on a matrix of stainless steel with circular internal niches (Ø = 10.0 mm; h = 2.0 mm. Next, they were subjected to thermal treatment in a heated chamber at 170 °C for 10 minutes. They were then divided randomly into four subgroups (Sg to receive the surface treatment according to the finishing/polishing systems tested (n = 10: Sg A: Control; Sg B: Diamond® felt disc + Diamond Excel® diamond paste; Sg C: Sof-Lex® discs; and Sg D: Enhance™ silicon tips. The mean roughness (Ra was determined using a digital surface roughnes tester. Data was analyzed by two-way ANOVA and Tukey's post-hoc test (α = 0.05. Differences between the surface treatments were found on both resins (p < 0.05. In G1, the lowest mean Ra values were observed using Sg C (0.07 μm and the highest for Sg D (0.12 μm (p < 0.05. There was no difference between Sg B (0.08 μm and Sg C (0.07 μm (p = 0.076. In G2, there was a progressive increase in mean Ra values from Sg D (0.05 μm to Sg C (0.06 μm and to Sg B (0.07 μm (p < 0.05. It was concluded that the finishing/polishing systems modified Ra on both resins.

  2. Study of the Al-Si-X system by different cooling rates and heat treatment

    Directory of Open Access Journals (Sweden)

    Miguel Angel Suarez

    2012-10-01

    Full Text Available The solidification behavior of the Al-12.6% Si (A1, the hypereutectic Al-20%Si (A2 and the Al-20%Si-1.5% Fe-0.5%Mn (A3 (in wt. (% alloys, at different cooling rates is reported and discussed. The cooling rates ranged between 0.93 °C/s and 190 °C/s when cast in sand and copper wedge-shaped molds, respectively. A spheroidization heat treatment was carried out to the alloys in the as-cast condition at 540 °C for 11 hours and quench in water with a subsequent heat treatment at 170 °C for 5 hours with the purpose of improving the mechanical properties. The samples were characterized by optical microscopy, scanning electron microscopy and mechanically by tensile test, in order to evaluate the response of the heat treatment on the different starting microstructures and mechanical properties. It was found that alloys cooled at rates greater than 10.8 °C/s had a smaller particle size and better distribution, also showed a greater response to spheroidization heat treatment of all silicon (Si phases. The spheroidization heat treatment caused an increase in the ultimate tensile stress (UTS and elongation when compared with the alloys in the as-cast condition. The highest UTS value of 174 MPa was obtained for the (A1 alloy.

  3. Heat treatment of the EN AC-AlSi9Cu3(Fe alloy

    Directory of Open Access Journals (Sweden)

    J. Pezda

    2010-04-01

    Full Text Available Silumins are widely used in automotive, aviation and shipbuilding industries; as having specific gravity nearly three times lower than specific gravity of cast iron the silumins can be characterized by high mechanical properties. Additionally, they feature good casting properties, good machinability and good thermal conductivity. i.e. properties as required for machinery components operating in high temperatures and at considerable loads. Mechanical properties of the silumins can be upgraded, implementing suitably selected heat treatment. In the paper is presented an effect of modification and heat treatment processes on mechanical properties of the EN AC-AlSi9Cu3(Fe alloy. Investigated alloy has undergone typical processes of modification and refining, and next heat treatment. Temperature range of the heat treatment operations was determined on base of curves from the ATD method. Obtained results concern registered melting and solidification curves from the ATD method and strength tests. On base of the performed tests one has determined range of the heat treatment parameters which would assure obtainment of the best possible mechanical properties of the EN AC-AlSi9Cu3(Fe alloy.

  4. Effect of Cold Drawing and Heat Treatment on the Microstructure of Invar36 Alloy Wire

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seung Youb; Jang, Seon Ah; Eun, Hee-Chul; Choi, Jung-Hoon; Lee, Ki Rak; Park, Hwan Seo; Ahn, Do-Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Soo Young; Kim, Jea Youl [RandD Center, KOS Ltd., Yangsan (Korea, Republic of); Shin, Sang Yong [University of Ulsan, Ulsan (Korea, Republic of)

    2016-10-15

    In this study, the effect of cold drawing and heat treatment on the microstructure of Invar36 alloy wire was investigated. Invar36 alloy wire is used as a transmission line core material, and is required to have high strength. The diameter of the Invar36 alloy wire specimens were reduced from 16 mm to 4.3 mm after three cold drawing and two heat treatment processes, thereby increasing tensile strength. Specimens were taken after each of the cold drawing and heat treatment processes, and their microstructure and tensile properties were analyzed. The Invar36 alloy wire had a γ-(Fe, Ni) phase matrix before the cold drawing and heat treatment processes. After the cold drawing processes, {220} and {200} textures were mainly achieved. After the heat treatment processes, a {200} recrystallization γ-(Fe, Ni) phase was formed with fine carbides. The recrystallization γ-(Fe, Ni) phase grains had low dislocation density, so they probably accommodated a large amount of deformation during the cold drawing processes.

  5. Effects of temperature and method of heat treatment on myofibrillar proteins of pork

    Directory of Open Access Journals (Sweden)

    Vujadinović Dragan

    2014-01-01

    Full Text Available During the tests in this paper, meat processing was carried out at different temperatures between the range of 51°C to 100°C. The meat was processed by dry heat (roasting and wet heat treatments (cooking in water at atmospheric pressure. After heat treatment, myofibrillar proteins were extracted from solutions at constant ionic strength. Quantitative and qualitative determinations of protein´s fractions were performed by capillary electrophoresis. Myofibrillar proteins were also analized for fresh pork meat sample. Results obtained in fresh meat were compared with those recorded after roasting and cooking. In the fresh and thermally processed pork the following proteins were identified: myosin, light chain 3; myosin, light chain 2; troponin - C; troponin - I; myosin, light chain 1; tropomyosin; troponin - T; actin; desmin; α - actinin; C - protein; M - protein (Mβ; M - protein (Mα; heavy meromyosin - HMM. For both methods of thermal processing, with increasing heat treatment temperature, concentration of soluble protein in the extract decreases rapidly after 51°C. Cooking treatment had a more intense effect on the proteins change and denaturation than roasting. [Projekat Ministartsva nauke Republike Srbije: Effect of heat treatment temperature on protein structure and properties of pork meat

  6. Functional Properties of Glutinous Rice Flour by Dry-Heat Treatment

    OpenAIRE

    Qin, Yang; Liu, Chengzhen; Jiang, Suisui; Cao, Jinmiao; Xiong, Liu; Sun, Qingjie

    2016-01-01

    Glutinous rice flour (GRF) and glutinous rice starch (GRS) were modified by dry-heat treatment and their rheological, thermal properties and freeze-thaw stability were evaluated. Compared with the native GRF and GRS, the water-holding ability of modified GRF and GRS were enhanced. Both the onset and peak temperatures of the modified samples increased while the endothermic enthalpy change decreased significantly (p < 0.05). Meanwhile, dry heating remarkably increased the apparent viscosities o...

  7. Effect of heat-moisture treatment on the structural, physicochemical, and rheological characteristics of arrowroot starch.

    Science.gov (United States)

    Pepe, Larissa S; Moraes, Jaqueline; Albano, Kivia M; Telis, Vânia R N; Franco, Célia M L

    2016-04-01

    The effect of heat-moisture treatment on structural, physicochemical, and rheological characteristics of arrowroot starch was investigated. Heat-moisture treatment was performed with starch samples conditioned to 28% moisture at 100 ℃ for 2, 4, 8, and 16 h. Structural and physicochemical characterization of native and modified starches, as well as rheological assays with gels of native and 4 h modified starches subjected to acid and sterilization stresses were performed. Arrowroot starch had 23.1% of amylose and a CA-type crystalline pattern that changed over the treatment time to A-type. Modified starches had higher pasting temperature and lower peak viscosity while breakdown viscosity practically disappeared, independently of the treatment time. Gelatinization temperature and crystallinity increased, while enthalpy, swelling power, and solubility decreased with the treatment. Gels from modified starches, independently of the stress conditions, were found to have more stable apparent viscosities and higher G' and G″ than gels from native starch. Heat-moisture treatment caused a reorganization of starch chains that increased molecular interactions. This increase resulted in higher paste stability and strengthened gels that showed higher resistance to shearing and heat, even after acid or sterilization conditions. A treatment time of 4 h was enough to deeply changing the physicochemical properties of starch. © The Author(s) 2015.

  8. Heat Treatment and Properties of Iron and Steel

    Science.gov (United States)

    1966-11-01

    piece of a carbon or low- alloy steel in the low temperature range used for tempering from the color of the thin oxide film that forms on the cleaned... Carbonitriding 16 d. Nitriding : IQ 5.6. Surface hardening 17 a. Induction hardening 17 b. Flame hardening 17 5.7. Special treatments 17 a...steels and in cast irons. These are manganese, silicon , phosphorus, and sulfur. Steels may be broadly classified into two types, (1) carbon and (2

  9. Effect of heat treatment on gravity die-cast Sc-A356 aluminium alloy

    Directory of Open Access Journals (Sweden)

    Lim Ying Pio

    2017-01-01

    Full Text Available The effects of scandium addition (0.00 wt.%, 0.2 wt.%, 0.4 wt.% and 0.6 wt.% and T6 heat treatment on the microstructure and mechanical properties of A356 aluminium alloy have been investigated in the research reported in this paper. The Sc inoculated specimens were prepared by gravity die-casting, according to ASTM B557-06 standard. The cast samples were then subjected to heat treatment at solutionizing temperature of 540 °C for 8 h followed by water quenching and artificial aging at 160 °C for 6 h. The microstructure, microhardness and tensile strength of the heat-treated samples were examined with use of scanning electron microscope (SEM, optical microscope, Vicker’s hardness tester, and Instron static machine respectively. Heat treatment was found to be able to effectively reduce grain size down to 16 μm (0.6 wt.% Sc, from 40 μm (original A356. The tensile strength was significantly improved, up to 338 MPa for heat treated 0.6 wt.% Sc-A356 having been achieved. The microhardness of 118 HV has been obtained for heat treated 0.6 wt.%Sc-A356.

  10. Effects of heat stress on the level of heat shock protein 70 on the surface of hepatocellular carcinoma Hep G2 cells: implications for the treatment of tumors.

    Science.gov (United States)

    Cui, Naizhong; Xu, Yongping; Cao, Zhenhui; Xu, Fanxing; Zhang, Peng; Jin, Liji

    2013-04-01

    The ability to distinguish tumor cells from normal cells is vital to allow the immune system to selectively destroy tumor cells. In order to find an effective marker, we used enzyme-linked immunosorbent assay, immunocytochemistry, immunofluorescence, and flow cytometry to investigate the effects of heat stress on the amount of heat shock protein 70 on the surface of tumor cells (Hep G2 cells). Heat shock protein 70 is the major stress-induced heat shock protein found on the surface of tumor cells. Our results indicate that the percentage of Hep G2 cells with a detectable level of heat shock protein 70 on their cell surface increased significantly (P heat stress at 42 °C for 2 h (up to 1.92 times the level before heat treatment). The detectable level of heat shock protein 70 on the surface of Hep G2 cells reached its peak 12 h after treatment. However, the fluorescent intensity of stressed and unstressed Hep G2 cells was not significantly different (P > 0.05). The increase in the level of heat shock protein 70 on the surface of tumor cells following heat stress could provide a basis for finding novel immunotoxins as targets for drug action and may have application to be used in conjunction with hyperthermia in the treatment of tumors.

  11. The composition, heating value and renewable share of the energy content of mixed municipal solid waste in Finland.

    Science.gov (United States)

    Horttanainen, M; Teirasvuo, N; Kapustina, V; Hupponen, M; Luoranen, M

    2013-12-01

    For the estimation of greenhouse gas emissions from waste incineration it is essential to know the share of the renewable energy content of the combusted waste. The composition and heating value information is generally available, but the renewable energy share or heating values of different fractions of waste have rarely been determined. In this study, data from Finnish studies concerning the composition and energy content of mixed MSW were collected, new experimental data on the compositions, heating values and renewable share of energy were presented and the results were compared to the estimations concluded from earlier international studies. In the town of Lappeenranta in south-eastern Finland, the share of renewable energy ranged between 25% and 34% in the energy content tests implemented for two sample trucks. The heating values of the waste and fractions of plastic waste were high in the samples compared to the earlier studies in Finland. These high values were caused by good source separation and led to a low share of renewable energy content in the waste. The results showed that in mixed municipal solid waste the renewable share of the energy content can be significantly lower than the general assumptions (50-60%) when the source separation of organic waste, paper and cardboard is carried out successfully. The number of samples was however small for making extensive conclusions on the results concerning the heating values and renewable share of energy and additional research is needed for this purpose. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Research on the mechanical, thermal, induction heating and healing properties of steel slag/steel fibers composite asphalt mixture

    NARCIS (Netherlands)

    Liu, Quantao; Li, Bin; Schlangen, H.E.J.G.; Sun, Yihan; Wu, Shaopeng

    2017-01-01

    In this paper, steel slag/steel fiber composite asphalt mixture were prepared. The effects of the addition of steel slag and/or steel fibers on the mechanical, thermal, induction heating and healing properties of asphalt mixture were investigated. The results showed that adding steel slag and/or

  13. Nutrient recovery from airplane wastewater: composition, treatment and ecotoxicological assay.

    Science.gov (United States)

    Filho, Jorge Luiz da Paixão; Tonetti, Adriano Luiz; Guimarães, Martha Tavanielli; Silva, Dailto

    2017-04-01

    For the 2014 World Cup and the 2016 Olympic Games, Brazil has expanded its airport infrastructure. This will lead to an increase in wastewater generation from aircrafts. This wastewater is traditionally taken from the aircrafts and disposed in the public sewage collection system. However, this residual water may have a different composition than the usual sanitary sewage. Therefore, it is important to study an alternative to treat this kind of wastewater. Thus, the objective of this study was to characterize and analyze the treatment of wastewater from airplane toilets through chemical precipitation for the removal of ammonia in the form of struvite. The airplanes' effluent showed a composition similar to human urine with pH 8.9, ammonia nitrogen 4,215 mg L(-1), phosphorus 430 mg L(-1) and a very high acute toxicity (Vibrio fischeri). The best treatment for struvite formation was with pH 9.0 and molar ratio Mg:NH4:PO4 equal to 1.5:1.0:1.0. In this case, the removal of ammonia and phosphorus achieved 97.0% and 95.3%, respectively. After this procedure, the toxicity by Vibrio fischeri decreased.

  14. Hydrogen Degassing Study During the Heat Treatment of 1.3-GHZ SRF Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Joung, Mijoung [Fermilab; Kim, H. J. [IBS, Daejeon; Rowe, A. [Fermilab; Wong, M. [Fermilab

    2013-10-02

    Superconducting radio frequency (SRF) cavities undergo a number of processes as part of its manufacturing procedure in order to optimize their performance. Among these processes is a high temperature hydrogen degas heat treatment used to prevent 'Q' decrease. The heat treatment occurs in the processing sequence after either chemically or mechanically polishing the cavity. This paper summarizes the hydrogen measurements during the heat treatment of a sample of chemically and mechanically polished single-cell and nine-cell 1.3-GHz cavities. The hydrogen measurements are analyzed according the polishing method, the polishing history, the amount of time that the cavity was baked at 800°C, and the temperature ramp rate.

  15. Heat treatment of processing sludge of ornamental rocks: application as pozzolan in cement matrices

    Directory of Open Access Journals (Sweden)

    J.G. Uliana

    Full Text Available The sector of ornamental rocks produces significant volume of waste during the sawing of the blocks and demand to find ways to recycle, given its environmental impact. Considering the possibilities of use of industrial by-products as mineral admixtures, aiming at sustainable development in the construction industry, this paper aims to study the performance of the processing sludge of ornamental rocks and grinding after heat treatment, based on their potential application as partial substitute for cement. The residue was characterized, cast and milled to produce glassy material. Was analyzed the mechanical performance and pozzolanic activity with partial replacement of cement by waste in natural condition and after heat treatment in mortars for comparison. The results were promising, so it was possible to verify that after heat treatment, the treated waste is presented as a material with pozzolanic characteristics.

  16. Heuristic algorithm for planning and scheduling of forged pieces heat treatment

    Directory of Open Access Journals (Sweden)

    R. Lenort

    2012-04-01

    Full Text Available The paper presents a heuristic algorithm for planning and scheduling of forged pieces heat treatment which allows maximizing the capacity exploitation of the heat treatment process and the entire forging process. Five Focusing Steps continuous improvement process was selected as a methodological basis for the algorithm design. Its application was supported by simulation experiments performed on a dynamic computer model of the researched process. The experimental work has made it possible to elicit the general rules for planning and scheduling of the heat treatment process of forged pieces which reduce losses caused by equipment conversion and setup times, and which increase the throughput of this process. The HIPO diagram was used to design the algorithm.

  17. Examination of the influence of heat treatment on the properties of Al-Si alloys

    Energy Technology Data Exchange (ETDEWEB)

    Vuksanovic, D.; Rakocevic, S. [Faculty of Metallurgy, Podgorica (RS); Markovic, S. [Faculty of Technology and Metallurgy, Belgrade (RS); Petrovic, T. [Institute ' Kirilo Savic' , Belgrade (RS); Kovacevic, K. [Institute for Ferrous Metallurgy (RS); Tripkovic, S. [H.K. Petar Drapsin, Mladenovac (RS)

    2007-08-15

    In this paper the influence of heat treatment on the structural and mechanical properties of Al-Si alloys was investigated. Silicon content in the examined alloys was in the range 11 to 14%, the contents of the other alloying elements were in the standard range but all alloys were modified with strontium. The regime of the applied heat treatment was quenching (520 C/6h - cooling in water) + aging (205oC/7h - air cooling). The examinations were carried out at room temperature as well as at 250 C and 300 C. The obtained results showed a positive influence of the applied heat treatment on the mechanical properties of the examined alloys. The improvement of the mechanical properties can be considered as a consequence of a redistribution and change of morphology of the phases present in the structure of the alloys. (orig.)

  18. EFFECT OF HEAT TREATMENT ON THE GERMINATION OF SEEDS SOEL

    Directory of Open Access Journals (Sweden)

    Y. M’Sadak

    2015-01-01

    Full Text Available The object of this work was to study the effect of thermal treatments (in the oven and in the compost on the seed germination SOEL. The laboratory evaluation on the treatment in the oven berries at two temperatures (50°C and 60°C for three exposure time ( one day, two days and three days gave a germination rate zero for 60°C for an exposure time of one day. The spatio-temporal thermal monitoring of forestry compost windrow which was introduced to deal with berries SOEL showed a substantially homogeneous distribution of the temperature rising to 60°C and even longer swath stretching and used for a time period of 5 consecutive days. The germination rate was zero for all fruit seeds treated before the first reversal fact, regardless of the depth and location of the windrow considered that the berries were introduced. Thus, composting can be a solution to prevent the spread of SOEL by seed.

  19. Evolution of the properties of ZnO thin films subjected to heating treatments

    Energy Technology Data Exchange (ETDEWEB)

    Prepelita, Petronela; Stefan, N.; Luculescu, C.; Garoi, F., E-mail: florin.garoi@gmail.com; Birjega, R.

    2012-05-01

    Structural and optical properties of ZnO thin films (200 nm thickness) deposited using magnetron sputtering technique are influenced by structural defects. Therefore, we applied various heating treatments in order to control and improve the crystallinity of the samples. These treatments were realized in air at temperatures of 350 Degree-Sign C, 550 Degree-Sign C and 700 Degree-Sign C respectively, each for a duration of 1 h. The properties of the samples were investigated both before and after the heating treatment. Modern methods like X-ray Diffraction, Atomic Force Microscopy and Scanning Electron Microscopy were used to analyze the structure and morphology of the heated ZnO thin films. These heating treatments may be held responsible for rearrangements in the morphology of the thin films. Thus, it was observed that an increase of porosity and agglomeration of the crystallites is followed by an increase in the size of the crystallites. Inter-crystalline borders will migrate determining a coalescence of several crystallites during the heating process, as well. As a consequence, an increase of the band gap width from 3.26 eV to 3.30 eV (at 350 Degree-Sign C) and 3.32 eV (at 550 Degree-Sign C) respectively, occurred.

  20. Combined effects of chlorine dioxide, drying, and dry heat treatments in inactivating microorganisms on radish seeds.

    Science.gov (United States)

    Bang, Jihyun; Kim, Haeyoung; Kim, Hoikyung; Beuchat, Larry R; Ryu, Jee-Hoon

    2011-02-01

    We determined the combined effectiveness of ClO(2) (200 and 500 μg/ml, 5 min), air drying [25 °C, 40% relative humidity (RH), 2 h], and mild dry heat (55 °C, 23% RH, up to 48 h) treatments in killing total aerobic bacteria (TAB), Escherichia coli O157:H7, and molds and yeasts (MY) on radish seeds. A 5.1-log reduction in the number of TAB was achieved on radish seeds treated with 200 or 500 μg/ml ClO(2) followed by air drying for 2 h and dry heat treatment for 48 h or 24 h, respectively. When radish seeds were treated with 200 and 500 μg/ml ClO(2), air dried, and heat treated for 12 h and 6 h, respectively, the initial population of E. coli O157:H7 (5.6 log CFU/g) on seeds was reduced to an undetectable level (heat treatment up to 48 h. Results show that treating radish seeds with 500 μg/ml ClO(2), followed by air dried at 25 °C for 2 h and heat treatment at 55 °C for 36 h achieved a >5-log CFU/g reduction of TAB and E. coli O157:H7. These observations will be useful when developing effective strategies and practices to enhance the microbiological safety of radish sprouts. Copyright © 2010 Elsevier Ltd. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Kwon; Lee, Jae Young; Lim, Soo Hyun; Park, Ji Hwan; Seo, Bo Min; Kim, Seon Hwa [Soonchunhyang University, Asan (Korea, Republic of)

    2002-06-15

    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({alpha}) 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{approx}71 mV, that of the 900 .deg. C heat treated steel pipe measured only 10mV. The results were explained and discussed

  2. The effects of wet heat treatment on the structural and chemical components of Bacillus sporothermodurans spores.

    Science.gov (United States)

    Tabit, Frederick T; Buys, Elna

    2010-06-15

    The objective of this research was to study the rate of structural damage and survival of Bacillus sporothermodurans spores following treatment at high temperatures by determining the amount of Dipicolinic acid (DPA) and soluble protein leakage over time. A reference strain of B. sporothermodurans (DSM 10599) and a South African strain (UP20A) isolated from UHT milk were used. To determine the survival of spores at 130 degrees C, spores were heated for 4, 8 and 12min. To check the viability of spores plate counts were determined, while structural damage was determined using the Transmission Electron Microscopy. The filtrate of the heated spore suspension was analysed for the amount of DPA and soluble protein release due to heating. The amount of DPA released was quantified by HPLC analysis while the amount of soluble protein released from heated spores was quantified using the Bradford method. The log values of spore counts, released DPA and soluble proteins from triplicate experiments were analysed. The results of this study indicate that the inactivation of B. sporothermodurans spores during wet heat treatment is due to the penetration of hot moisture into the spore which then moistens the spore components, and inactivates enzymes, and because of the high water pressure, vital spore components such as proteins and DPA in solution leak out of the spore. Interestingly a vast majority of heated spores were inactivated before a significant amount of DPA was released. This research is the first to determine the effect of high temperature wet heat treatment on the structure of B. sporothermodurans spores and has given an insight regarding the mechanisms of destruction of B. sporothermodurans spores by wet heat. Copyright 2010 Elsevier B.V. All rights reserved.

  3. Effects of water restriction following feeding on nutrient digestibilities, milk yield and composition and blood hormones in lactating Holstein cows under heat stress conditions

    Directory of Open Access Journals (Sweden)

    Jalil Ghassemi Nejad

    2015-08-01

    Full Text Available The effects of water restriction following feeding under heat stress conditions on nutrient digestibilities, milk yield and composition and some blood hormones in lactating Holstein cows were evaluated. The design was completely randomized with 30 high producing lactating Holstein cows (80.8±40.5 DIM which were assigned to two treatment groups (15 cows per treatment. Treatments were free access to water (FAW and 2 h water restriction (2hWR following feeding. Average temperature-humidity index (THI in the farm was over 80 throughout the experiment which defines heat stress conditions. Neutral detergent fibre, organic matter and ether extract digestibilities increased by water restriction (P0.05. Water intake was recorded daily during the digestibility period and was not different between FAW and 2hWR group (P>0.05. Fat corrected milk was higher in 2hWR group than FAW group (P0.05. Somatic cell counts were greater in 2hWR than FAW group (P0.05. Blood prolactin and growth hormone were higher in 2hWR group than the FAW group (P<0.05. It is concluded that water restriction for 2 hours following feeding improved nutrient digestibility of some dietary components and increased milk fat percentage in lactating Holstein cows under heat stress conditions.

  4. EFFECT OF PRE-HEAT TREATMENT ON MECHANICAL PROPERTIES OF Ti-6Al-4V WELDS

    Directory of Open Access Journals (Sweden)

    Gnofam Jacques TCHEIN

    2016-11-01

    Full Text Available The work presented here is related to the optimization of the Friction Stir Welding (FSW process. The objective is to study the influence of some parameters used in the production of welded joints by FSW. The most important parameters are the welding speed and the rotational speed of the tool. The effect of pre-heat treatment on the plates to be welded is also studied by the design of experimental methods. These pre-heat treatments result not only in a change of mechanical properties of plates to be welded, but also of their microstructure. The experiments were performed following a 16 lines fractional Taguchi table.

  5. Technoeconomic Optimization of Waste Heat Driven Forward Osmosis for Flue Gas Desulfurization Wastewater Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Gingerich, Daniel B [Carnegie Mellon Univ., Pittsburgh, PA (United States); Bartholomew, Timothy V [Carnegie Mellon Univ., Pittsburgh, PA (United States); Mauter, Meagan S [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2017-06-26

    With the Environmental Protection Agency’s recent Effluent Limitation Guidelines for Steam Electric Generators, power plants are having to install and operate new wastewater technologies. Many plants are evaluating desalination technologies as possible compliance options. However, the desalination technologies under review that can reduce wastewater volume or treat to a zero-liquid discharges standard have a significant energy penalty to the plant. Waste heat, available from the exhaust gas or cooling water from coal-fired power plants, offers an opportunity to drive wastewater treatment using thermal desalination technologies. One such technology is forward osmosis (FO). Forward osmosis utilizes an osmotic pressure gradient to passively pull water from a saline or wastewater stream across a semi-permeable membrane and into a more concentrated draw solution. This diluted draw solution is then fed into a distillation column, where the addition of low temperature waste heat can drive the separation to produce a reconcentrated draw solution and treated water for internal plant reuse. The use of low-temperature waste heat decouples water treatment from electricity production and eliminates the link between reducing water pollution and increasing air emissions from auxiliary electricity generation. In order to evaluate the feasibility of waste heat driven FO, we first build a model of an FO system for flue gas desulfurization (FGD) wastewater treatment at coal-fired power plants. This model includes the FO membrane module, the distillation column for draw solution recovery, and waste heat recovery from the exhaust gas. We then add a costing model to account for capital and operating costs of the forward osmosis system. We use this techno-economic model to optimize waste heat driven FO for the treatment of FGD wastewater. We apply this model to three case studies: the National Energy Technology Laboratory (NETL) 550 MW model coal fired power plant without carbon

  6. Vapor-Phase Stoichiometry and Heat Treatment of CdTe Starting Material for Physical Vapor Transport

    Science.gov (United States)

    Su, Ching-Hua; Sha, Yi-Gao; Lehoczky, S. L.; Liu, Hao-Chieh; Fang, Rei; Brebrick, R. F.

    1998-01-01

    Six batches of CdTe, having total amounts of material from 99 to 203 g and gross mole fraction of Te, X(sub Te), 0.499954-0.500138, were synthesized from pure Cd and Te elements. The vapor-phase stoichiometry of the assynthesized CdTe batches was determined from the partial pressure of Te2, P(sub Te2) using an optical absorption technique. The measured vapor compositions at 870 C were Te-rich for all of the batches with partial pressure ratios of Cd to Te2, P(sub Cd)/P(sub Te2), ranging from 0.00742 to 1.92. After the heat treatment of baking under dynamic vacuum at 870 C for 8 min, the vapor-phase compositions moved toward that of the congruent sublimation, i.e. P(sub Cd)/P(sub Te2) = 2.0, with the measured P(sub Cd)/P(sub Te2) varying from 1.84 to 3.47. The partial pressure measurements on one of the heat-treated samples also showed that the sample remained close to the congruent sublimation condition over the temperature range 800-880 C.

  7. Effects of thermal and enzymatic treatments and harvesting time on the microbial quality and chemical composition of fibre hemp (Cannabis sativa L.)

    DEFF Research Database (Denmark)

    Nykter, M.; Kymalainen, H.R.; Thomsen, Anne Belinda

    2008-01-01

    The aim of the present study was to examine the effects of pectinase enzyme treatment followed by thermal treatments (steam explosion and dry heating) on the microbial quality and chemical composition of hemp fibres. Before these treatments, the fibres were separated manually from the stems...... materials. Dry heating had no effect on mould and bacterial counts at temperatures below 120 degrees C and durations less than 60 min. The chemical composition was affected by the enzymatic treatment due to extraction and degradation of water-soluble components, pectin and ash. Thus the cellulose content...... harvested after stand retting in the field before frost, after early frost or in the following spring. The enzymatic treatment of hemp promoted growth of moulds on the fibres (500-fold increase in colony-forming units (cfu)), whereas steam explosion reduced the amount of moulds to a relatively constant...

  8. Compositional and morphological analysis of FeW films modified by sputtering and heating

    Directory of Open Access Journals (Sweden)

    Petter Ström

    2017-08-01

    Full Text Available Surface compositional changes of iron-tungsten films by deuterium (D ion bombardment were studied by means of medium energy ion scattering, elastic recoil detection analysis and Rutherford backscattering spectrometry. The energy of the bombarding ions was 200eV/D and the fluence was varied from 1021 D/m2 to 1024D/m2. A significant increase of the tungsten concentration within the 20nm closest to the sample surface, caused by preferential sputtering of iron, was seen for the films exposed 1023D/m2 or more. In the sample exposed to the highest fluence, 1024D/m2, the concentration of tungsten was increased from an initial 1.7 at. % up to approximately 24 at. % averaged over the 5nm closest to the surface. The analysis was complicated by the presence of oxygen on the sample surfaces. In order to study the thermal stability of the tungsten enriched layer, the sample initially exposed to 1023 D/m2 at room temperature was heated to 400 °C in the measurement chamber for medium energy ion scattering and several spectra were recorded at intermediate temperatures. The obtained data showed that the layer was relatively stable below 200 °C whereas a drastic change in the film composition occurred between 200 °C and 250 °C due to interdiffusion of iron and silicon, the latter of which was the substrate material. The surface morphologies of the films were probed with atomic force microscopy showing that protrusions of 10–100nm width appeared after deuterium bombardment at fluences higher than 1022D/m2.

  9. Vacuum evaporation treatment of digestate: full exploitation of cogeneration heat to process the whole digestate production.

    Science.gov (United States)

    Guercini, S; Castelli, G; Rumor, C

    2014-01-01

    Vacuum evaporation represents an interesting and innovative solution for managing animal waste surpluses in areas with high livestock density. To reduce operational costs, a key factor is the availability of an inexpensive source of heat, such as that coming from an anaerobic digestion (AD) plant. The aim of this study was to test vacuum evaporation for the treatment of cattle slurry digestate focusing on heat exploitation. Tests were performed with a pilot plant fed with the digestate from a full-scale AD plant. The results were used to evaluate if and how cogeneration heat can support both the AD plant and the subsequent evaporation of the whole daily digestate production in a full-scale plant. The concentrate obtained (12% total solids) represents 40-50% of the influent. The heat requirement is 0.44 kWh/kg condensate. Heat power availability exceeding the needs of the digestor ranges from 325 (in winter) to 585 kW (in summer) versus the 382 kW required for processing the whole digestate production. To by-pass fluctuations, we propose to use the heat coming from the cogenerator directly in the evaporator, tempering the digestor with the latent heat of distillation vapor.

  10. Impact of Heat Treatment on the Freezing Points of Cow and Goat Milk

    Directory of Open Access Journals (Sweden)

    Bohumíra Janštová

    2009-01-01

    Full Text Available The aim of this study was to monitor the impact of heat treatment variables on the freezing point of cow and goat milk. The freezing point (FP was established in 30 bulk tank samples of goat milk and in 30 bulk tank samples of cow milk which were subject to laboratory heat treatment at temperatures of 72 °C (A, 85 °C (B, 95 °C (C, with the same exposition times of 20 s. Freezing point measurements of raw and heat-treated milk were carried out in compliance with the Standard CTS 57 0538 by a thermistor cryoscope. The FP of raw cow milk increased with heat treatment from the initial values of -0.5252 ± 0.0114 °C (O by 0.0023 °C (A, 0.0034 °C (B and 0.0051°C (C. Changes in FP values of goat milk were detected, from its initial value of –0.5530 ± 0.0086 °C there was an increase in the FP depending on the mode of heat treatment due to pasteurization by an average of 0.0028 °C (A, 0.0036 °C (B and 0.0054 °C (C. The dynamics of the changes were similar both in goat and cow milk. Freezing point values in cow and goat milk differed (P ⪬ 0.01 when compared to the freezing point of untreated milk after the individual interventions as well as when compared between each other. An increase in the heat treatment temperature of cow and goat milk causes an increase in the freezing point (a shift towards zero. These results can be used in practice for checking the raw material in dairy industry.

  11. Effect of grinding and heat treatment on the mechanical behavior of zirconia ceramic

    Directory of Open Access Journals (Sweden)

    Gabriela Freitas RAMOS

    2016-01-01

    Full Text Available Abstract The present study investigated the effect of grinding on roughness, flexural strength, and reliability of a zirconia ceramic before and after heat treatment. Seven groups were tested (n = 15: a control group (labeled CG, untreated, and six groups of samples ground with diamond discs, simulating diamond burs, with grits of 200 µm (G80; 160 µm (G120, and 25 µm (G600, either untreated or heat-treated at 1200°C for 2 h (labeled A. Yttria tetragonal zirconia polycrystal discs were manufactured, ground, and submitted to roughness and crystalline phase analyses before the biaxial flexural strength test. There was no correlation between roughness (Ra and Rz and flexural strength. The reliability of the materials was not affected by grinding or heat treatment, but the characteristic strength was higher after abrasion with diamond discs, irrespective of grit size. The X-ray diffraction data showed that grinding leads to a higher monoclinic (m phase content, whereas heat treatment produces reverse transformation, leading to a fraction of m-phase in ground samples similar to that observed in the control group. However, after heat treatment, only the G80A samples presented strength similar to that of the control group, while the other groups showed higher strength values. When zirconia pieces must be adjusted for clinical use, a smoother surface can be obtained by employing finer-grit diamond burs. Moreover, when the amount of monoclinic phase is related to the degradation of zirconia, the laboratory heat treatment of ground pieces is indicated for the reverse transformation of zirconia crystals.

  12. Fluxless Brazing and Heat Treatment of a Plate-Fin Sandwich Actively Cooled Panel

    Science.gov (United States)

    Beuyukian, C. S.

    1978-01-01

    The processes and techniques used to fabricate plate-fin sandwich actively cooled panels are presented. The materials were 6061 aluminum alloy and brazing sheet having clad brazing alloy. The panels consisted of small scale specimens, fatigue specimens, and a large 0.61 m by 1.22 m test panel. All panels were fluxless brazed in retorts in heated platen presses while exerting external pressure to assure intimate contact of details. Distortion and damage normally associated with that heat treatment were minimized by heat treating without fixtures and solution quenching in an organic polymer solution. The test panel is the largest fluxless brazed and heat treated panel of its configuration known to exist.

  13. On post-weld heat treatment cracking in tig welded superalloy ATI 718Plus

    Directory of Open Access Journals (Sweden)

    G. Asala

    2016-01-01

    Full Text Available The susceptibility of heat affected zone (HAZ to cracking in Tungsten Inert Gas (TIG welded Allvac 718Plus superalloy during post-weld heat treatment (PWHT was studied. Contrary to the previously reported case of low heat input electron beam welded Allvac 718Plus, where HAZ cracking occurred during PWHT, the TIG welded alloy is crack-free after PWHT, notwithstanding the presence of similar micro-constituents that caused cracking in the low input weld. Accordingly, the formation of brittle HAZ intergranular micro-constituents may not be a sufficient factor to determine cracking propensity, the extent of heat input during welding may be another major factor that influences HAZ cracking during PWHT of the aerospace superalloy Allvac 718Plus.

  14. On post-weld heat treatment cracking in tig welded superalloy ATI 718Plus

    Science.gov (United States)

    Asala, G.; Ojo, O. A.

    The susceptibility of heat affected zone (HAZ) to cracking in Tungsten Inert Gas (TIG) welded Allvac 718Plus superalloy during post-weld heat treatment (PWHT) was studied. Contrary to the previously reported case of low heat input electron beam welded Allvac 718Plus, where HAZ cracking occurred during PWHT, the TIG welded alloy is crack-free after PWHT, notwithstanding the presence of similar micro-constituents that caused cracking in the low input weld. Accordingly, the formation of brittle HAZ intergranular micro-constituents may not be a sufficient factor to determine cracking propensity, the extent of heat input during welding may be another major factor that influences HAZ cracking during PWHT of the aerospace superalloy Allvac 718Plus.

  15. Influence of Heat Treatment on the Morphologies of Copper Nanoparticles Based Films by a Spin Coating Method

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2017-01-01

    Full Text Available We have investigated the influence of heat treatment on the morphologies of copper nanoparticles based films on glass slides by a spin coating method. The experiments show that heat treatment can modify the sizes and morphologies of copper nanoparticles based films on glass slides. We suggest that through changing the parameters of heat treatment process may be helpful to vary the scattering and absorbing intensity of copper nanoparticles when used in energy harvesting/conversion and optical devices.

  16. The influence of distal-end heat treatment on deflection of nickel-titanium archwire

    Directory of Open Access Journals (Sweden)

    Marcelo Faria da Silva

    2016-02-01

    Full Text Available Objective: The aim of this in vitro study was to evaluate the deflection-force behavior of nickel-titanium (NiTi orthodontic wires adjacent to the portion submitted to heat treatment. Material and Methods: A total of 106 segments of NiTi wires (0.019 x 0.025-in and heat-activated NiTi wires (0.016 x 0.022-in from four commercial brands were tested. The segments were obtained from 80 archwires. For the experimental group, the distal portion of each segmented archwire was subjected to heat treatment (n = 40, while the other distal portion of the same archwire was used as a heating-free control group (n = 40. Deflection tests were performed in a temperature-controlled universal testing machine. Unpaired Student's t-tests were applied to determine if there were differences between the experimental and control groups for each commercial brand and size of wire. Statistical significance was set at p < 0.05. Results: There were no statistically significant differences between the tested groups with the same size and brand of wire. Conclusions: Heat treatment applied to the distal ends of rectangular NiTi archwires does not permanently change the elastic properties of the adjacent portions.

  17. Proteomic profiling of camel and cow milk proteins under heat treatment.

    Science.gov (United States)

    Felfoul, Imène; Jardin, Julien; Gaucheron, Frédéric; Attia, Hamadi; Ayadi, M A

    2017-02-01

    Cow and camel milk proteins before and after heat treatment at 80°C for 60min were identified using LC/MS and LC-MS/MS following monodimensional electrophoresis. The database used for the identification of camel and cow proteins was set from http://www.uniprot.org/. The obtained results showed that, after heating, camel milk at 80°C for 60min, camel α-lactalbumin (α-la) and peptidoglycan recognition protein (PGRP) were not detected while camel serum albumin (CSA) was significantly diminished. When heating cow milk at 80°C for 60min, α-lactalbumin (α-la) and β-lactoglobulin (β-lg) were not significantly detected. Moreover, 19 protein bands from SDS-PAGE were analyzed and a total of 45 different proteins were identified by LC-MS/MS. Casein fractions were kept intact under a heat treatment of 80°C during 60min of both camel and cow milks. Camel and bovine whey proteins were affected by a heat treatment of 80°C for 60min. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Improvement in the mechanical properties of PTFE bonded NdFeB magnets by heat treatment

    Science.gov (United States)

    Tattam, C.; Williams, A. J.; Hay, J. N.; Harris, I. R.; Tedstone, S. F.; Ashraf, M. M.

    1996-05-01

    Rotary forging has been used to produce high density bonded magnets using NdFeB based melt spun ribbons (MQP-D). The binder used was polytetrafluoroethylene (PTFE). A post-forging heat treatment at temperatures above the crystalline melting point of PTFE (˜ 340°C) has been seen to improve substantially the mechanical integrity of the compacts. Heat treatments that were undertaken in air resulted in oxidation of the magnets, but the extent of oxidation was reduced with increasing PTFE content, characterised by a greater retention of magnetic properties. This behaviour suggests that to some extent. PTFE is effective as a barrier to oxidation. By heat treating in a vacuum, an improvement of over 100% in the mechanical strength of the compacts could be obtained with little loss in the magnetic properties. The fracture surfaces of both as-forged and heat treated compacts have been examined using scanning electron microscopy and it appears that bonding between the melt spun ribbon (MQI) and PTFE occurs during heat treatment.

  19. Study on Disinfestation of Fruit Fly (Bactrocera dorsalis using Vapor Heat Treatment on Gedong Gincu Mango

    Directory of Open Access Journals (Sweden)

    Rokhani Hasbullah

    2009-04-01

    Full Text Available Since the prohibition of chemical method for insect disinfestations processes such as ethylene dibromide in 1984, heat treatment method was developed as quarantine technology. One of the heat treatment methods is vapor heat treatment (VHT. The objectives of this research were to study mortality of fruit fly (Bactrocera dorsalis and to study the responses of VHT on quality of gedong gincu mango. Fruit fly mortality due to heat has been investigated by immersing fruit fly eggs into heated water at temperatures of 40, 43, 46 and 49OC for 30 minutes immersed, also at temperature of 46OC for 5, 10, 15, 20, 25 and 30 minutes. Gedong gincu mangoes were treated at temperature 46.5OC for 0, 10, 20, and 30 minutes. The results showed that mortality has been achieved 100% at temperature more than and equal to 43OC for 30 minutes and at temperature 46OC for more than and equal to 10 minutes. The VHT has significantly and fungi population although without adversely affecting to the fruit quality and there were no significant change in the fruit weight loss, hardness, color, soluble solid content, water content, vitamin C and organoleptic test. VHT at temperature 46.5OC for 20 up to 30 minutes were effective to kill fruit flies inside mangoes and were able to maintaining mango quality during storage.

  20. Analysis of Thermal Stresses and Strains Developing during the Heat Treatment of Windmill Shaft

    Directory of Open Access Journals (Sweden)

    Cebo-Rudnicka A.

    2017-06-01

    Full Text Available In the paper the results of evaluation of the temperature and stress fields during four cycles of the heat treatment process of the windmill shaft has been presented. The temperature field has been calculated from the solution to the heat conduction equation over the whole heat treatment cycles of the windmill shaft. To calculate the stress field an incremental method has been used. The relations between stresses and strains have been described by Prandtl-Reuss equation for the elastic-plastic body. In order to determine the changes in the temperature and stress fields during heat treatment of the windmill shaft self-developed software utilizing the Finite Element Method has been used. This software can also be used to calculate temperature changes and stress field in ingots and other axially symmetric products. In the mathematical model of heating and cooling of the shaft maximum values of the strains have been determined, which allowed to avoid the crack formation. The critical values of strains have been determined by using modified Rice and Tracy criterion.

  1. Influence of heat treatment on physicochemical and rheological characteristics of natural yogurts

    Directory of Open Access Journals (Sweden)

    Juliana Aparecida Célia

    2017-08-01

    Full Text Available The aim of this study was to assess the influence of heat treatment on physicochemical and rheological characteristics of natural yogurts, as well as the influence of lyophilization process on natural yogurts after reconstitution. In the first experiment, three yogurt treatments were processed, as follows: Treatment 1, yogurt produced with raw refrigerated milk; Treatment 2, yogurt produced with refrigerated pasteurized milk; and Treatment 3, yogurt produced with UHT (ultra-high temperature milk, in addition to analyses of fat, protein, moisture, titratable acidity, and pH. The shelf life of yogurts at 1, 8, 15, 22, and 29 days of storage, as well as pH, acidity, syneresis, viscosity, viable lactic bacteria, and total coliforms were also assessed. In the second experiment, yogurts were submitted to lyophilization process, performed by scanning electron microscopy analysis and subsequently in those reconstituted, in addition to being assessed the physicochemical, rheological, and viable lactic bacteria characteristics. The results found in the first experiment showed that heat treatment was positive for viscosity, syneresis, and lactic bacteria, being viable until the 15th day of storage only for yogurts submitted to heat treatment. In the second experiment, lyophilization preserved the physicochemical characteristics of yogurts, but the number of initial lactic bacteria was different, also negatively affecting yogurt viscosity.

  2. Influence of heat treatment on the strength and fracture toughness of 7N01 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bo [School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan (China); Wang, Xiaomin, E-mail: xmwang991011@163.com [School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan (China); Chen, Hui; Hu, Jie [School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan (China); Huang, Cui [School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan (China); Gou, Guoqing [School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan (China)

    2016-09-05

    7N01 aluminum (Al) alloys are treated by five heat treatment methods as peak aging (T6), over aging (T74), high temperature and subsequently low temperature aging (HLA), retrogression and reaging (RRA) and double retrogression and reaging (DRRA). The strength and fracture toughness of the five samples are tested, and the microstructures are investigated by optical microscopy (OM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The results show that 7N01 Al-alloy treated at T6 condition has high strength but low fracture toughness. Compared with T6 treatment, T74 and HLA treatments increase the fracture toughness by 67% and 90% respectively, while the strength decrease by 9% and 17%. RRA process is a proper treatment method for 7N01 which improves the fracture toughness without sacrificing strength. The fracture toughness of DRRA treated alloy is much lower than that of RRA. Quantitative analysis through TEM images shows that the heat treatment affects the mechanical properties of 7N01 Al-alloy highly through changing the precipitates in grains and on grain boundaries, which can be explained by the coherency strengthening mechanism and Orowan mechanism. - Highlights: • Five heat treatments which can change the properties of 7N01 Al alloy were designed. • Quantitative analysis of precipitates was employed to study the mechanism. • RRA treatment can make proper strength/toughness property balances for 7N01 Al alloy.

  3. Relationship between Secondary Structure and Surface Hydrophobicity of Soybean Protein Isolate Subjected to Heat Treatment

    Directory of Open Access Journals (Sweden)

    Zhongjiang Wang

    2014-01-01

    Full Text Available This study investigated relationship between secondary structure and surface hydrophobicity of soy protein isolate (SPI subjected to a thermal treatment at 70~90°C. Heat denaturation increased the surface hydrophobicity and surface hydrophobicity decreased as aggregate formed. Heat caused an increase in the relative amount of α-helix structures and an overall decrease in the amount of β-sheet structures when compared with nontreated SPI. The relative amounts of secondary structures varied with time, temperature, and intensity of heat treatment applied. The β-sheet structure was most important for its significant role in denaturation of 7S globulin and following formed aggregates and even in denaturation of 11S globulin. The amount of β-sheet structure in SPI had an inverse correlation with the surface hydrophobicity when the temperature was kept below 90°C. Besides, β-turn structure increased as β-7S/B-11S aggregate formated.

  4. Implantable polymer/metal thin film structures for the localized treatment of cancer by Joule heating

    Science.gov (United States)

    Kan-Dapaah, Kwabena; Rahbar, Nima; Theriault, Christian; Soboyejo, Wole

    2015-04-01

    This paper presents an implantable polymer/metal alloy thin film structure for localized post-operative treatment of breast cancer. A combination of experiments and models is used to study the temperature changes due to Joule heating by patterned metallic thin films embedded in poly-dimethylsiloxane. The heat conduction within the device and the surrounding normal/cancerous breast tissue is modeled with three-dimensional finite element method (FEM). The FEM simulations are used to explore the potential effects of device geometry and Joule heating on the temperature distribution and lesion (thermal dose). The FEM model is validated using a gel model that mimics biological media. The predictions are also compared to prior results from in vitro studies and relevant in vivo studies in the literature. The implications of the results are discussed for the potential application of polymer/metal thin film structures in hyperthermic treatment of cancer.

  5. Effect of Intercritical Heat Treatment on Mechanical Properties of Reinforcing Steel Bars

    Directory of Open Access Journals (Sweden)

    MUHAMMAD ISHAQUE ABRO

    2017-07-01

    Full Text Available Intercritical heat treatments attempts were made to enhance the mechanical properties of reinforcing steel bars milled from scrap metal. For this, two grades of steel bars were obtained from different steel mills and their mechanical properties that include hardness, ultimate tensile strength, and percent elongation before and after intercritical heat treatment were determined. Results indicated that 25.5 and 17.6%, improvements in UTS (Ultimate Tensile Strength and 18.8 and 14.3% improvement in percent elongation in two grades of reinforcing steel samples containing 0.17 and 0.24% carbon respectively was achieved while heating at 750oC for 2h. Appreciable improvement in the mechanical properties was noted due to birth of sufficient quantity of martensite along with ferrite

  6. Influence of heat treatment on mechanical property of steel hollow sphere and its sheet construction

    Science.gov (United States)

    Yoshida, Yoshinori; Ozawa, Sho

    2017-10-01

    Heat treatments, water quenching and annealing, are performed on the metallic hollow spheres (MHS) made from steel with 4.0 mm in outer diameter. They are pierced then put on a piece of tungsten alloy wire for making a MHS thread. The thread is set in between two neighboring warps of the tungsten alloy and the thread is placed in a reticular pattern. The MHS fabric sheet which has plain weave structure is produced by the weaving process. Furthermore, a sandwich construction of the sheet with 2 sheets of aluminum plate. The influence of the heat treatments on difference of mechanical and energy absorption property are evaluated by mean of compression test for the sheet along with the thickness direction. In addition, an aluminum pipe is filled with a heat treated MHS sheet and compression test is performed for the pipe along the radial direction. Its difference of compression load and energy consumption property is investigated.

  7. Effect of heat treatment, top coatings and conversion coatings on the corrosion properties of black electroless Ni-P films

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y., E-mail: liu_yunli@hotmail.com [R and D Department, MacDermid plc, 198 Golden Hillock Road, Birmingham B11 2PN (United Kingdom); Beckett, D.; Hawthorne, D. [R and D Department, MacDermid plc, 198 Golden Hillock Road, Birmingham B11 2PN (United Kingdom)

    2011-02-15

    Electroless black nickel-phosphorus plating is an advanced electroless nickel plating process formulated to deposit a black finish when processed through an oxidizing acid solution. Heat treatment, five types of top organic coating techniques and one conversion coating technique with three different experimental conditions were investigated to stabilize the black film and increase the hardness and corrosion resistance. Morphology and compositions of electroless nickel-phosphorous films with or without heat treatment, with five types of top organic coatings, and with three conversion coatings were compared to examine nickel, phosphorus, oxygen, carbon, silicon and chrome contents on the corrosion resistance of black surfaces by energy dispersive X-ray microanalysis and scanning electron microscope. Corrosion resistance of black electroless nickel-phosphorus coatings with or without heat treatment, with five types of top organic coatings, and with three conversion coatings was investigated by the polarization measurements and the salt spray test in 5% NaCl solution, respectively. HydroLac as the top organic coating from MacDermid showed the excellent corrosion resistance and the black EN film did not lose the black color after 48 h salt spray test. Electrotarnil B process with 0.5 ASD for 1 min stabilized the black Ni-P film immediately and increased the hardness and corrosion performance of the black Ni-P film. The black Ni-P coating with Electroarnil B process passed the 5% NaCl salt spray test for 3000 h in the black color and had a minimal corrosion current 0.8547 {mu}A/cm{sup 2} by the polarization measurement.

  8. Structural ordering of coal char during heat treatment and its impact on reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Feng, B.; Bhatia, S.K.; Barry, J.C.

    2002-07-01

    The effect of heat treatment on the structure of an Australian semi-anthracite char was studied between 850-1150{sup o}C using XRD, HRTEM, and electrical resistivity techniques. It was found that the carbon crystallite size in the char does not change during heat treatment, for both the raw coal and its ash-free derivative obtained by acid treatment. However, the fraction of the organized carbon in the raw coal chars, determined by XRD, increased with increase of heat treatment time and temperature, while that for the ash-free coal chars remained unchanged. This suggests the occurrence of catalytic ordering during heat treatment. Electrical resistivity of the raw coal chars decreased with heat treatment, while that of the ash-free coal chars did not vary. High resolution transmission electron micrographs depicted well-organized carbon layers surrounding iron particles. The fraction of organized carbon attains an apparent equilibrium value that increases with increase in temperature. Good temperature-independent correlation was found between the electrical resistivity and the organized carbon fraction, indicating that electrical resistivity is structure sensitive. These results suggest that the thermal deactivation is the result of a crystallite-perfecting process, which is effectively catalyzed by the inorganic matter in the coal char. It is concluded that the process is diffusion controlled, most likely involving transport of iron in the inter-crystallite nanospaces in the temperature range studied. The activation energy of this transport process is found to be low, which is corroborated by model-free correlation of the temporal variation of organized carbon fraction as well as electrical resistivity data using the superposition method, and is suggestive of surface transport of iron.

  9. Applying Thermodynamics to Fossil Fuels: Heats of Combustion from Elemental Compositions.

    Science.gov (United States)

    Lloyd, William G.; Davenport, Derek A.

    1980-01-01

    Discussed are the calculations of heats of combustions of some selected fossil fuel compounds such as some foreign shale oils and United States coals. Heating values for coal- and petroleum-derived fuel oils are also presented. (HM)

  10. Comparison of the heat treatment response of wrought and SSM-HPDC alloy 6082

    CSIR Research Space (South Africa)

    Möller, H

    2011-06-01

    Full Text Available The natural and artificial aging responses of wrought and SSM-HPDC alloy 6082 are compared. It is shown that the heat treatment response of this Al-Mg-Si alloy is not influenced by differences in microstructures produced by different processing...

  11. Effects of heat treatment on antioxidative and anti-inflammatory properties of orange by-products

    Science.gov (United States)

    This study investigated the changes in functional components, antioxidative activities, antibacterial activities, anti-inflammatory activities of orange (Citrus sinensis (L.) Osbeck) by-products (OBP) by heat treatment at 50 and 100 degrees C (hereafter, 50D and 100D extracts, respectively). Optimal...

  12. T5 heat treatment of semi-solid metal processed aluminium alloy F357

    CSIR Research Space (South Africa)

    Moller, H

    2009-04-01

    Full Text Available properties of SSM-HPDC F357 in different temper conditions (F, T4, T5 and T6) are compared. The Quality Index (QI) is used to compare the influence of different T5 heat treatment parameters and different temper conditions....

  13. Effect of prolonged isothermal heat treatment on the mechanical behavior of advanced NANOBAIN steel

    Science.gov (United States)

    Avishan, Behzad

    2017-09-01

    The microstructural evolution and consequent changes in strength and ductility of advanced NANOBAIN steel during prolonged isothermal heat-treatment stages were investigated. The microstructure and mechanical properties of nanostructured bainite were not expected to be influenced by extending the heat-treatment time beyond the optimum value because of the autotempering phenomenon and high tempering resistance. However, experimental results indicated that the microstructure was thermodynamically unstable and that prolonged austempering resulted in carbon depletion from high-carbon retained austenite and carbide precipitations. Therefore, austenite became thermally less stable and partially transformed into martensite during cooling to room temperature. Prolonged austempering did not lead to the typical tempering sequence of bainite, and the sizes of the microstructural constituents were independent of the extended heat-treatment times. This independence, in turn, resulted in almost constant ultimate tensile strength values. However, microstructural variations enhanced the yield strength and the hardness of the material at extended isothermal heat-treatment stages. Finally, although microstructural changes decreased the total elongation and impact toughness, considerable combinations of mechanical properties could still be achieved.

  14. Heat treatment prior to testing allows detection of antigen of Dirofilaria immitis in feline serum.

    Science.gov (United States)

    Little, Susan E; Raymond, Melissa R; Thomas, Jennifer E; Gruntmeir, Jeff; Hostetler, Joe A; Meinkoth, James H; Blagburn, Byron L

    2014-01-13

    Diagnosis of Dirofilaria immitis infection in cats is complicated by the difficulty associated with reliable detection of antigen in feline blood and serum samples. To determine if antigen-antibody complex formation may interfere with detection of antigen in feline samples, we evaluated the performance of four different commercially available heartworm tests using serum samples from six cats experimentally infected with D. immitis and confirmed to harbor a low number of adult worms (mean = 2.0). Sera collected 168 (n = 6), 196 (n = 6), and 224 (n = 6) days post infection were tested both directly and following heat treatment. Antigen was detected in serum samples from 0 or 1 of 6 infected cats using the assays according to manufacturer's directions, but after heat treatment of serum samples, as many as 5 of 6 cats had detectable antigen 6-8 months post infection. Antibodies to D. immitis were detected in all six infected cats by commercial in-clinic assay and at a reference laboratory. These results indicate that heat treatment of samples prior to testing can improve the sensitivity of antigen assays in feline patients, supporting more accurate diagnosis of this infection in cats. Surveys conducted by antigen testing without prior heat treatment of samples likely underestimate the true prevalence of infection in cats.

  15. Effect of heat treatment and artificial ageing on Al-5Mg-2Zn

    CSIR Research Space (South Africa)

    Chauke, Levy

    2017-10-01

    Full Text Available -cast state (F temper condition) there should be non-equilibrium intermetallics remaining at grain boundaries after casting which could be detrimental to corrosion properties of the alloy. This study investigated the effect of heat treatment and artificial...

  16. Acrylamide resulting from heat-time treatment in Cajanus cajan , a ...

    African Journals Online (AJOL)

    The influence that heat-time treatment has on the concentration of acrylamide in roasted Cajanus cajan was analysed. The study focussed on optimising the roasting conditions using Response Surface Methodology (RSM) to minimise concentration of acrylamide in roasted Cajanus cajan. The raw Cajanus cajan was ...

  17. Effect of Heat Treatment on the Lycopene Content of Tomato Puree ...

    African Journals Online (AJOL)

    Lycopene is a powerful antioxidant. Epidemiological studies have associated its consumption with numerous health benefits. In this study the effects of heating on lycopene were investigated by exposing tomato (lycopersicon esculentum) puree to different temperature treatments (60, 90, 100, 120, and 1500C) for 5, 10, 30, ...

  18. Simulation of stretch forming with intermediate heat treatments of aircraft skins - A physically based modeling approach

    NARCIS (Netherlands)

    Kurukuri, S.; Miroux, Alexis; Wisselink, H.H.; van den Boogaard, Antonius H.

    2011-01-01

    In the aerospace industry stretch forming is often used to produce skin parts. During stretch forming a sheet is clamped at two sides and stretched over a die, such that the sheet gets the shape of the die. However for complex shapes it is necessary to use expensive intermediate heat-treatments in

  19. Influence of heat treatment and veneering on the storage modulus and surface of zirconia ceramic

    NARCIS (Netherlands)

    Siavikis, G.; Behr, M.; van der Zel, J.M.; Feilzer, A.J.; Rosentritt, M.

    2011-01-01

    Objectives: Glass-ceramic veneered zirconia is used for the application as fixed partial dentures. The aim of this investigation was to evaluate whether the heat treatment during veneering, the application of glass-ceramic for veneering or long term storage has an influence on the storage modulus of

  20. Investigation of structural modification and thermal characteristics of lignin after heat treatment.

    Science.gov (United States)

    Kim, Jae-Young; Hwang, Hyewon; Oh, Shinyoung; Kim, Yong-Sik; Kim, Ung-Jin; Choi, Joon Weon

    2014-05-01

    Milled wood lignin was subjected to heat treatment between 150 and 300°C to understand the pattern of its structural modification and thermal properties. When the temperature was elevated with interval of 50°C, the color of the lignin became dark brown and the lignin released various forms of phenols from terminal phenolic groups in the lignin, leading to two physical phenomena: (1) gradual weight loss of the lignin, up to 19% based on dry weight and (2) increase in the carbon content and decrease in the oxygen content. Nitrobenzene oxidation and (13)C NMR analyses confirmed a cleavage of β-O-4 linkage (depolymerization) and reduction of methoxyl as well as phenolic hydroxyl group were also characteristic in the lignin structure during heat treatment. Simultaneously with lignin depolymerization, GPC analysis provided a possibility that condensation between lignin fragments could also occur during heat treatment. TGA/DTG/DSC data revealed that thermal stability of lignin obviously increased after heat treatment, implicating the structural rearrangement of lignin to reduction of β-O-4 linkage as well as accumulation of CC bonds. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Effect of solution heat treatment time on a rheocast Al-Zn-Mg-Cu alloy

    CSIR Research Space (South Africa)

    Mazibuko, NE

    2011-06-01

    Full Text Available During rheo-high pressure die casting (R-HPDC) of Al-Zn-Mg-Cu alloys a coarse eutectic phase is formed. This eutectic phase is difficult to take into solution because of its size and it would require longer solution heat treatment times...

  2. Combined action of S-carvone and mild heat treatment on Listeria monocytogenes Scott A

    NARCIS (Netherlands)

    Karatzas, A.K.; Bennik, M.H.J.; Smid, E.J.; Kets, E.P.W.

    2000-01-01

    The combined action of the plant-derived volatile, S-carvone, and mild heat treatment on the food-borne pathogen, Listeria monocytogenes, was evaluated. The viability of exponential phase cultures grown at 8 °C could be reduced by 1.3 log units after exposure to S-carvone (5 mmol 1-1) for 30 min at

  3. Effect of thermal ammoniation and heat treatment on the faecal and ...

    African Journals Online (AJOL)

    Polyphenol content was reduced from 1,24 to 0,55%. This study was therefore conducted to determine the effect of thermal ammoniation and heat treatment of ... high-tannin grain in the diet on the performance of growing pigs. Experimental Procedures. Digestion trial. Grain sorghum with a polyphenol content of 1,24%.

  4. Effect of high-temperature heat treatment duration on the purity and ...

    Indian Academy of Sciences (India)

    The effect of high-temperature heat treatment on purity and structural changes of multiwalled carbon nanotubes (MWCNTs) were studied by subjecting the raw MWCNTs (pristine MWCNTs) to 2600°C for 60 and 120 min. Thermogravimetric analysis (TGA), X-ray diffraction, Raman spectroscopy, transmission electron ...

  5. Heat transfer in hybrid fibre reinforced concrete-steel composite column exposed to a gas-fired radiant heater

    Science.gov (United States)

    Štefan, R.; Procházka, J.; Novák, J.; Fládr, J.; Wald, F.; Kohoutková, A.; Scheinherrová, L.; Čáchová, M.

    2017-09-01

    In the paper, a gas-fired radiant heater system for testing of structural elements and materials at elevated temperatures is described. The applicability of the system is illustrated on an example of the heat transfer experiment on a hybrid fibre reinforced concrete-steel composite column specimen. The results obtained during the test are closely analysed by common data visualization techniques. The experiment is simulated by a mathematical model of heat transfer, assuming the material data of the concrete determined by in-house measurements. The measured and calculated data are compared and discussed.

  6. Retained austenite variation in dual-phase steel after mechanical stressing and heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Giordano, L.; Tiziani, A.; Zambon, A. (Dipt. di Innovazione Meccanica e Gestionale, Padua Univ. (Italy)); Matteazzi, P. (Ist. di Chimica, Univ. di Udine (Italy))

    1991-01-20

    Retained austenite changes in a dual-phase steel have been studied after mechanical and thermal treatments. In order to determine the quantitative variations of retained austenite, whose amount in the examined steel is of the order of 5%, Moessbauer spectroscopy has been used. Retained austenite undergoes a martensitic transformation during deformation, but does not transform under the heat treatments performed on the sheet during anticorrosion and painting processes. (orig.).

  7. Successful Treatment of Cutaneous Botryomycosis with a Combination of Minocycline and Topical Heat Therapy

    Directory of Open Access Journals (Sweden)

    Masaya Ishibashi

    2012-05-01

    Full Text Available Cutaneous botryomycosis is a chronic focal infection characterized by a granulomatous inflammatory response to bacterial pathogens such as Staphylococcus aureus. Treatment requires antibiotic therapy and may also require surgical debridement. We employed topical heat therapy and oral minocycline. The lesions became flattened and pigmented after 1 month. We consider that this simple treatment can be an effective and harmless complementary therapy for cutaneous botryomycosis.

  8. Effect of heat treatment changes on swelling treatment of coal; Sekitan no bojun shori sayo ni oyobosu netsushori henka no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Satsuka, T.; Mashimo, K.; Wainai, T. [Nihon University, Tokyo (Japan). College of Science and Technology

    1996-10-28

    Discussions were given on effects of heat treatment at relatively low temperatures as a pretreatment for coal liquefaction on coal swelling and hydrogenolysis reaction. Taiheiyo coal was heated to 200{degree}C for one hour as a pretreatment. The attempted heating methods consisted of four steps of rapid heating (6.7{degree}C/min)quenching (20{degree}C/min), rapid heating/natural cooling (0.7{degree}C/min), heating (1.0{degree}C/min)/quenching, and heating/natural cooling. The swelling treatment was composed of adding methanol benzene into heat treated coal, and leaving it at room temperature for 24 hours. The hydrogenolysis was carried out by using a tetralin solvent and at an initial hydrogen pressure of 20 kg/cm{sup 2} and a temperature of 350{degree}C and for a time of one hour. Hydrogenolysis conversion in the heat treated coal was found lower than that of the original coal because of generation of liquefaction inactive components due to thermal polymerization. When the heat treated coal is swollen by using the solvent, gas yield from the hydrogenolysis reaction decreased due to gas suppression effect, and the conversion was lower than that of the original coal. Heat treatment suggests densification of the coal structure. Swollen coal shows no conspicuous difference in the heat treatment methods against the hydrogenolysis due to the swelling effect. 3 refs., 5 figs., 1 tab.

  9. Effects of Heat Input on the Chemical Composition and Hardness of ...

    African Journals Online (AJOL)

    This study examines the thermochemical reactions which alter weld metal chemistry by applying the arc heat considering the convective, radiation and arc heat losses. From numerical analysis, it was found that the radiation heat loss was dominant in the welding process which confirms the claims made by other ...

  10. Denaturation and Oxidative Stability of Hemp Seed (Cannabis sativa L.) Protein Isolate as Affected by Heat Treatment.

    Science.gov (United States)

    Raikos, Vassilios; Duthie, Garry; Ranawana, Viren

    2015-09-01

    The present study investigated the impact of heat treatments on the denaturation and oxidative stability of hemp seed protein during simulated gastrointestinal digestion (GID). Heat-denatured hemp protein isolate (HPI) solutions were prepared by heating HPI (2 mg/ml, pH 6.8) to 40, 60, 80 and 100 °C for 10 min. Heat-induced denaturation of the protein isolates was monitored by polyacrylamide gel electrophoresis. Heating HPI at temperatures above 80 °C significantly reduced solubility and led to the formation of large protein aggregates. The isolates were then subjected to in vitro GID and the oxidative stability of the generated peptides was investigated. Heating did not significantly affect the formation of oxidation products during GID. The results suggest that heat treatments should ideally remain below 80 °C if heat stability and solubility of HPI are to be preserved.

  11. Effect of oxidation heat treatment on the bond strength between a ceramic and cast and milled cobalt-chromium alloys.

    Science.gov (United States)

    Li, Jieyin; Ye, Xiuhua; Li, Bohua; Liao, Juankun; Zhuang, Peilin; Ye, Jiantao

    2015-08-01

    There is a dearth of dental scientific literature on the effect of different oxidation heat treatments (OHTs) (as surface pretreatments) on the bonding performance of cast and milled cobalt-chromium (CoCr) alloys. The objective of this study was to evaluate the effect of different OHTs on the bond strength between a ceramic and cast and milled CoCr alloys. Cobalt-chromium metallic specimens were prepared using either a cast or a milled method. Specimens were subjected to four different OHT methods: without OHT; OHT under normal atmospheric pressure; OHT under vacuum; and OHT under vacuum followed by sandblasting. The metal-ceramic bond strength was evaluated using a three-point bending test according to ISO9693. Scanning electron microscopy and energy-dispersive spectroscopy were used to study the specimens' microstructure and elemental composition. The bond strength was not affected by the CoCr manufacturing method. Oxidation heat treatment performed under normal atmospheric pressure resulted in the highest bond strength. The concentration of oxygen on the alloy surfaces varied with the different pretreatment methods in the following order: OHT under normal atmospheric pressure > OHT under vacuum > without OHT ≈ OHT under vacuum followed by sandblasting. © 2015 Eur J Oral Sci.

  12. Structural and Optical Properties of CuInS2 Thin Films Prepared by Magnetron Sputtering and Sulfurization Heat Treatment

    Directory of Open Access Journals (Sweden)

    Rongfeng Guan

    2015-01-01

    Full Text Available CuInS2 thin films were prepared by sulfurization of Cu-In precursor films through magnetron sputtering and the resulting films characterized using X-ray diffraction, Raman spectrometry, and UV-Vis spectrophotometry. The results demonstrate that a sputtering power of 80–120 W is more suitable for sputtered Cu-In precursor films and can be used to obtain CuInS2 films with good crystallinity through vulcanization heat treatment. The sputtering gas pressure and sulfurization temperature were shown to impact on the film quality due to improper processes during the CuInS2 phase. Some of the CuIn11S17 and CuS2 impurities were observed in the composition of the prepared CuInS2 thin films. Optimization of process parameters obtained from the experimental data was determined as a sputtering power of 80~120 W, a sputtering gas pressure of 0.6–0.8 Pa, a heat treatment temperature of 450~470°C, and a holding time of 2~3 hours. The optical band gap obtained for CuInS2 thin films is between 1.48 and 1.5 eV.

  13. Inactivation of Listeria monocytogenes using Water Bath Heat Treatment in Vacuum Packed Ricotta Salata Cheese Wedges.

    Science.gov (United States)

    Spanu, Carlo; Scarano, Christian; Spanu, Vincenzo; Pala, Carlo; Di Salvo, Riccardo; Piga, Carlo; Ullu, Antonio; Casti, Daniele; Lamon, Sonia; Cossu, Francesca; Ibba, Michela; De Santis, Enrico Pietro Luigi

    2015-07-01

    Ricotta salata cheese is frequently contaminated on the surface with Listeria monocytogenes. Water bath heat treatment in vacuum packed whole ricotta salata cheese wheels demonstrated to be effective in inactivating L. monocytogenes. However, the risk of cross-contamination in ricotta salata wedges is increased during cheese cutting. Therefore, the effectiveness of heat treatment in ricotta salata wedges has to be demonstrated conducting a new validation study. In this study, 9 different time temperature combinations, 75, 85, and 90 °C applied for 10, 20, and 30 min each, were tested on artificially contaminated ricotta salata cheese wedges. The extent of the lethal effect on L. monocytogenes was assessed 1 and 30 d after the application of the hot water bath treatment. Five of 9 combinations, 75 °C for 30 min, 85 °C for 20, and 30 min, and 90°C for 20 and 30 min, demonstrated to meet the process criteria of at least 5 log reduction. Sensory analyses were also conducted in order to account for the potential impact on sensory features of ricotta salata wedges, which showed no significant differences between treatments. This study allowed to select water bath heat treatments of vacuum packed ricotta salata wedges effective to reduce L. monocytogenes contamination. Such treatments can be successfully applied by food business operator to meet compliance with microbiological criteria through the designated shelf-life. © 2015 Institute of Food Technologists®

  14. Heat Treatment of Buckypaper for Use in Volatile Organic Compounds Sampling

    Directory of Open Access Journals (Sweden)

    Jonghwa Oh

    2016-01-01

    Full Text Available Three types of buckypapers (BPs, two of them fabricated with arc discharge (AD single-walled carbon nanotubes (SWNTs (acetone-cleaned AD BP and methanol-cleaned AD BP and one with high-pressure carbon monoxide (HiPco SWNTs (HiPco BP, were heat-treated at different conditions to find the specific conditions for each type that improve the adsorption properties. Based on thermogravimetric analysis (TGA data, three heat treatment conditions were designed for the AD BPs and another three conditions for the HiPco BPs. Also, changes in weight and physical integrity before and after the heat treatment were considered. Heating at 300°C for 90 minutes was selected for acetone-cleaned AD BP, in which the BP kept its physical integrity and yielded a relatively high Brunauer, Emmett, and Teller (BET surface area (970 ± 18 m2/g, while methanol-cleaned AD BP was excluded because of its physical change. For HiPco BP, a condition of 300°C heating for 30 minutes was chosen as a relatively higher surface area (933 ± 54 m2/g and less weight loss (5% were observed.

  15. Curie Temperature and Microstructural Changes Due to the Heating Treatment of Magnetic Amorphous Materials

    Directory of Open Access Journals (Sweden)

    Gondro J.

    2016-03-01

    Full Text Available Three distinct alloys: Fe86Zr7Nb1Cu1B5, Fe82Zr7Nb2Cu1B8, and Fe81Pt5Zr7Nb1Cu1B5 were characterized both magnetically and structurally. The samples, obtained with spinning roller method as a ribbons 3 mm in width and 20 μm thick, were investigated as-quenched and after each step of a multi steps heating treatment procedure. Each sample was annealed at four steps, fifteen minutes at every temperature, starting from 573K+600K up to +700K depending on type of alloy. Mössbauer spectroscopy data and transmission electron microscope (HRE M pictures confirmed that the as-quenched samples are fully amorphous. This is not changed after the first stages of treatment heating leads to a reduction of free volumes. The heating treatment has a great influence on the magnetic susceptibilities. The treatment up to 600K improves soft magnetic properties: an χ increase was observed, from about 400 to almost 1000 for the samples of alloys without Pt, and from about 200 to 450 at maximum, for the Fe81Pt5Zr7Nb1Cu1B5. Further heating, at more elevated temperatures, leads to magnetic hardening of the samples. Curie temperatures, established from the location of Hopkinson’s maxima on the χ(T curve are in very good agreement with those obtained from the data of specific magnetization, σ(T, measured in a field of 0.75T. As a critical parameter β was chosen to be equal 0.36 for these calculations, it confirmed that the alloys may be considered as ferromagnetic of Heisenberg type. Heating treatment resulted in decreasing of TC. These changes are within a range of several K.

  16. Preferences for heat, cold, or contrast in patients with knee osteoarthritis affect treatment response

    Directory of Open Access Journals (Sweden)

    Craig R Denegar

    2010-07-01

    Full Text Available Craig R Denegar, Devon R Dougherty, Jacob E Friedman, Maureen E Schimizzi, James E Clark, Brett A Comstock, William J KraemerHuman Performance Laboratory and Physical Therapy Program, Department of Kinesiology, University of Connecticut, Storrs, CT, USAObjective: This investigation assessed preferences for, and effects of, 5 days of twice daily superficial heat, cold, or contrast therapy applied with a commercially available system ­permitting the circulation of water through a wrap-around garment, use of an electric heating pad, or rest for patients with level II–IV osteoarthritis (OA of the knee.Methods: We employed a within subject, randomized order design to study 34 patients ­receiving each treatment in 1-week blocks. A knee injury and osteoarthritis outcome score (KOOS questionnaire and visual analog pain scale was completed at baseline, and twice each week. Treatment preferences were assessed in the last week of the study.Results: Treatment with the device set to warm was preferred by 48% of subjects. Near equal preferences were observed for cold (24% and contrast (24%. Pain reduction and improvements in KOOS subscale measures were demonstrated for each treatment but responses were (P < 0.05 greater with preferred treatments. Most patients preferred treatment with the water circulating garment system over a heating pad.Conclusions: We recommend that when superficial heat or cold is considered in the management of knee OA that patients experiment to identify the intervention that offers them the greatest relief and that contrast is a treatment option.Keywords: pain scales, KOOS, therapeutic agents, knee, patient preferences

  17. Proteomic Profiling Comparing the Effects of Different Heat Treatments on Camel (Camelus dromedarius) Milk Whey Proteins.

    Science.gov (United States)

    Benabdelkamel, Hicham; Masood, Afshan; Alanazi, Ibrahim O; Alzahrani, Dunia A; Alrabiah, Deema K; AlYahya, Sami A; Alfadda, Assim A

    2017-03-28

    Camel milk is consumed in the Middle East because of its high nutritional value. Traditional heating methods and the duration of heating affect the protein content and nutritional quality of the milk. We examined the denaturation of whey proteins in camel milk by assessing the effects of temperature on the whey protein profile at room temperature (RT), moderate heating at 63 °C, and at 98 °C, for 1 h. The qualitative and quantitative variations in the whey proteins before and after heat treatments were determined using quantitative 2D-difference in gel electrophoresis (DIGE)-mass spectrometry. Qualitative gel image analysis revealed a similar spot distribution between samples at RT and those heated at 63 °C, while the spot distribution between RT and samples heated at 98 °C differed. One hundred sixteen protein spots were determined to be significantly different (p milk samples. Eighty protein spots were decreased in common in both the heat-treated samples and an additional 25 spots were further decreased in the 98 °C sample. The proteins with decreased abundance included serum albumin, lactadherin, fibrinogen β and γ chain, lactotransferrin, active receptor type-2A, arginase-1, glutathione peroxidase-1 and, thiopurine S, etc. Eight protein spots were increased in common to both the samples when compared to RT and included α-lactalbumin, a glycosylation-dependent cell adhesion molecule. Whey proteins present in camel milk were less affected by heating at 63 °C than at 98 °C. This experimental study showed that denaturation increased significantly as the temperature increased from 63 to 98 °C.

  18. Proteomic Profiling Comparing the Effects of Different Heat Treatments on Camel (Camelus dromedarius) Milk Whey Proteins

    Science.gov (United States)

    Benabdelkamel, Hicham; Masood, Afshan; Alanazi, Ibrahim O.; Alzahrani, Dunia A.; Alrabiah, Deema K.; AlYahya, Sami A.; Alfadda, Assim A.

    2017-01-01

    Camel milk is consumed in the Middle East because of its high nutritional value. Traditional heating methods and the duration of heating affect the protein content and nutritional quality of the milk. We examined the denaturation of whey proteins in camel milk by assessing the effects of temperature on the whey protein profile at room temperature (RT), moderate heating at 63 °C, and at 98 °C, for 1 h. The qualitative and quantitative variations in the whey proteins before and after heat treatments were determined using quantitative 2D-difference in gel electrophoresis (DIGE)-mass spectrometry. Qualitative gel image analysis revealed a similar spot distribution between samples at RT and those heated at 63 °C, while the spot distribution between RT and samples heated at 98 °C differed. One hundred sixteen protein spots were determined to be significantly different (p milk samples. Eighty protein spots were decreased in common in both the heat-treated samples and an additional 25 spots were further decreased in the 98 °C sample. The proteins with decreased abundance included serum albumin, lactadherin, fibrinogen β and γ chain, lactotransferrin, active receptor type-2A, arginase-1, glutathione peroxidase-1 and, thiopurine S, etc. Eight protein spots were increased in common to both the samples when compared to RT and included α-lactalbumin, a glycosylation-dependent cell adhesion molecule. Whey proteins present in camel milk were less affected by heating at 63 °C than at 98 °C. This experimental study showed that denaturation increased significantly as the temperature increased from 63 to 98 °C. PMID:28350354

  19. Effects Of The Combined Heat And Cryogenic Treatment On The Stability Of Austenite In A High Co-Ni Steel

    Directory of Open Access Journals (Sweden)

    Gruber M.

    2015-09-01

    Full Text Available The stability of austenite is one of the most dominant factors affecting the toughness properties of high Co-Ni steels such as Aermet 100 and AF1410. Thus, the aim of this work was to get a deeper understanding on the impact of combined heat and cryogenic treatment on the stability of retained and reverted austenite. In order to characterize the evolution of the phase fraction of austenite during tempering at different temperatures and times, X-ray diffraction analyses were carried out. The stability of austenite, which was formed during tempering, was analyzed with dilatometric investigations by studying the transformation behavior of the austenite during cooling from tempering temperature down to −100°C. Additionally, transmission electron microscopy investigations were performed to characterize the chemical composition and phase distribution of austenite and martensite before and after tempering.

  20. OBTAINMENT AND PHYSICO-MECHANICAL PROPERTIES OF THE FOAMED HEAT-INSULATING MATERIAL BASED ON ALKALI SILICATE COMPOSITION AND SHUNGITE

    Directory of Open Access Journals (Sweden)

    V. A. Lomonosov

    2015-01-01

    Full Text Available Physical and mechanical properties of foamed heat-insulating material based on alkali silicate composition and shungite were investigated. The studies determined the ratio of the components of the charge with which it is possible to obtain the optimal ratio of mechanical properties/thermal conductivity. Found that composite materials obtained from shungite filler, have a more porous structure (up to 76% of the volume of the material and are more uniform distribution of pore size (from 0.11 to 0.2 mm

  1. Creep rupture properties of P122 and P92 steel HAZs simulated by heat treatments and by a weld simulator

    Energy Technology Data Exchange (ETDEWEB)

    Albert, S.K. [IGCAR, Kalpakkam (India); Matsui, M. [Mitsubushi Heavy Industries, Nagasaki (Japan); Watanabe, T.; Hongo, H.; Kubo, K.; Tabuchi, M. [National Inst. for Materials Science, Ibaraki (Japan)

    2002-07-01

    In the present study, creep rupture properties of the heat affected zones (HAZs) of P122 and P92 steels, simulated by a heat treatments and by a weld simulator, are studied and compared with those of the actual weld joint. Specimen blanks cut out from steel plates were heated to different peak temperatures that corresponds to intercritical HAZ (ICHAZ), fine grained HAZ (FGHAZ) and coarse grained HAZ (CGHAZ) both by heat treatment and by employing a weld simulator. These were then subjected to post weld heat treatment (PWHT) and creep specimens prepared from these blanks were tested at 923 K for various stress levels. Microstructure was uniform for the specimens with HAZ simulated by heat treatment while for those produced by weld simulator, the uniform microstructures corresponding to the peak temperature of simulation was confined to only {proportional_to}10 mm at the center of the specimens. (orig.)

  2. Effect of Heat Treatment on the Hardness and Wear of Grinding Balls

    Science.gov (United States)

    Aissat, Sahraoui; Sadeddine, Abdelhamid; Bradai, Mohand Amokrane; Younes, Rassim; Bilek, Ali; Benabbas, Abderrahim

    2017-09-01

    The effect quenching and tempering by different regimes on Rockwell hardness and wear processes of grinding balls 50 and 70 mm in diameter made of two melts of chromium-molybdenum cast iron is studied. The heating temperature for quenching is 850, 950, and 1050°C; the tempering temperature is 250, 400, and 600°C. Iron is analyzed in an electron microscope. Diffraction patterns are obtained. A model of cast iron wear is suggested and compared to the Davis model and to experimental results. An optimum heat treatment regime is proposed.

  3. 3D numerical modeling of coupled phenomena in induced processes of heat treatment with malice

    Directory of Open Access Journals (Sweden)

    Triwong Peeteenut

    2008-01-01

    Full Text Available This paper describes a multi-method Malice package for three dimension coupled phenomena in induced processes of heat treatment by an algorithm weakly coupled with the Migen package integral method defining the electromagnetic model and the Flux-Expert package finite element method defining the thermal model. The integral method is well suited to inductive systems undergoing sinusoidal excitation at midrange or high frequency. The unknowns of both models are current density, scalar potential and temperature. Joule power in the electromagnetic model is generated by Eddy currents. It becomes the heat source in the thermal model.

  4. Heat Treatment of Cold-Sprayed C355 Al for Repair: Microstructure and Mechanical Properties

    Science.gov (United States)

    Murray, J. W.; Zuccoli, M. V.; Hussain, T.

    2018-01-01

    Cold gas dynamic spraying of commercially pure aluminum is widely used for dimensional repair in the aerospace sector as it is capable of producing oxide-free deposits of hundreds of micrometer thickness with strong bonding to the substrate, based on adhesive pull-off tests, and often with enhanced hardness compared to the powder prior to spraying. There is significant interest in extending this application to structural, load-bearing repairs. Particularly, in the case of high-strength aluminum alloys, cold spray deposits can exhibit high levels of porosity and microcracks, leading to mechanical properties that are inadequate for most load-bearing applications. Here, heat treatment was investigated as a potential means of improving the properties of cold-sprayed coatings from Al alloy C355. Coatings produced with process conditions of 500 °C and 60 bar were heat-treated at 175, 200, 225, 250 °C for 4 h in air, and the evolution of the microstructure and microhardness was analyzed. Heat treatment at 225 and 250 °C revealed a decreased porosity ( 0.14% and 0.02%, respectively) with the former yielding slightly reduced hardness (105 versus 130 HV0.05 as-sprayed). Compressive residual stress levels were approximately halved at all depths into the coating after heat treatment, and tensile testing showed an improvement in ductility.

  5. Effects of heat treatment on mechanical and tribological properties of cobalt-base tribaloy alloys

    Science.gov (United States)

    Liu, Rong; Yao, Matthew X.; Patnaik, Prakash C.; Wu, Xijia

    2005-10-01

    Cobalt-base Tribaloy alloys are important wear-resistant materials, especially for high-temperature applications, because of the outstanding properties of the strengthened cobalt solid solution and the hard Laves intermetallic phase that make up the alloys. The Laves intermetallic phase is so abundant (35-70 vol.%) in these alloys that its presence governs all of the material properties. Heat treatment may alter the volume fraction, the size/shape, and the distribution of the Laves phase in the microstructures as well as the phase and structure of the cobalt solid solution, thus influencing the mechanical and tribological properties of the alloys. In this work, the effects of heat treatment on two cobalt-based Tribaloy alloys, T-400 and T-200, were studied. The former is a well-known Tribaloy alloy, and the latter is a newly developed one. These two alloys were heat treated in different conditions. The phases and microstructures of the alloys before and after the heat treatments were analyzed using x-ray and scanning electron microscopy. The mechanical and tribological properties of the alloys were investigated using a nano-indentation technique and a pin-on-disc tribometer, respectively.

  6. Lama Pemanasan Metode Vapor Heat Treatment (VHT dan Pelilinan untuk Mempertahankan Mutu Pepaya Selama Penyimpanan

    Directory of Open Access Journals (Sweden)

    Rokhani Hasbullah

    2008-04-01

    Full Text Available Horticulture products are host for Tephritidae fruitflies that are considered a quarantine risk by many importing countries. This research was conducted to find out the specific condition for the heat treatment using vapor heat treatment (VHT method to control pest and diseases of papaya and the fruit quality during storage. Papayas were vapor heat treated at medium temperature of 46.5 0C for 0, 15, and 30 minutes. After the treatment, the fruits were waxed using beeswax of 6 % in concentration and then stored at temperature of 10 0C. The results show that the fruitfly of oriental fruitfly (Bactrocera dorsalis was completely killed by treating in deep water testing at temperature of 46 0C for 10 minutes or at 43 0C for 30 minutes. The VHT of papaya at fruit core temperature of 45.5-46.0 0C for 15-30 minutes following waxing using beeswax of 6% in concentration was found to be effective to control pest and diseases until 21 days of storage without any visible signs of heat injury and without adversely affecting the quality of the fruit.

  7. Functional Properties of Glutinous Rice Flour by Dry-Heat Treatment.

    Science.gov (United States)

    Qin, Yang; Liu, Chengzhen; Jiang, Suisui; Cao, Jinmiao; Xiong, Liu; Sun, Qingjie

    2016-01-01

    Glutinous rice flour (GRF) and glutinous rice starch (GRS) were modified by dry-heat treatment and their rheological, thermal properties and freeze-thaw stability were evaluated. Compared with the native GRF and GRS, the water-holding ability of modified GRF and GRS were enhanced. Both the onset and peak temperatures of the modified samples increased while the endothermic enthalpy change decreased significantly (p dry heating remarkably increased the apparent viscosities of both GRF and GRS. Importantly, compared with GRS samples, the storage modulus (G') and loss modulus (G") values of modified GRF increased more greatly and the tanδ values decreased more remarkably, indicating that the dry-heat treatment showed more impact on the GRF and a higher viscoelasticity compared with GRS. Our results suggest the dry-heat treatment of GRF is a more effective method than that of GRS, which omits the complex and tedious process for purifying GRS, and thereby has more practical applications in the food industry.

  8. Heat treatment of TI-6AL-4V produced by lasercusing

    Directory of Open Access Journals (Sweden)

    Becker, Thorsten

    2015-08-01

    Full Text Available LaserCUSING® is a selective laser melting (SLM process that is capable of manufacturing parts by melting powder with heat input from a laser beam. LaserCUSING demonstrates potential for producing the intricate geometries specifically required for biomedical implants and aerospace applications. One main limitation to this form of rapid prototyping is the lack of published studies on the material performance of the resulting material. Studies of the material’s performance are often complicated by dependence on several factors, including starting powder properties, laser parameters, and post-processing heat treatments. This study aims to investigate the mechanical properties of LaserCUSING-produced Ti-6Al-4V and its performance relative to the conventional wrought counterpart. A combination of conventional and LaserCUSING-tailored heat treatments is performed. The resulting microstructures are studied and linked to the properties obtained from hardness tests. The findings highlight that LaserCused Ti-6Al-4V is competitive with traditional materials, provided that optimal parameters are chosen and parts are subject to tailored post-processing. In the as-built condition, LaserCused Ti-6Al-4V displays superior strength and hardness as a result of a martensitic microstructure, and a poorer performance in ductility. However, the material performance can be improved using tailored heat treatments. Careful consideration must be given to suitable post-processing before application in critical components in the aerospace or biomedical industry can occur

  9. Effect of variable heat treatment modes on microstructures of Fe-Cr-B cast iron alloy

    Directory of Open Access Journals (Sweden)

    Guo Changqing

    2008-02-01

    Full Text Available The effect of heat treatment mode on the microstructure of Fe-Cr-B cast iron alloys was investigated in this paper by comparing the difference of precipitation patterns of secondary particles after thermal cycling treatment (TCT with those after normal heat treatment (NHT. No obvious differences were found in precipitation patterns of secondary particles between TCT and NHT when experimental temperature was below Ar1. However, when temperature was over Ar1, there were significant differences, with secondary particles prominently segregated at the grain boundaries under TCT, while the particles evenly distributed in the matrix under NHT. The reason for the microstructure differences could be associated with the development of non-equilibrium segregation of boron during TCT.

  10. Karakteristik Fisikokimia Mie Kering Berbasis Pati Ubi Jalar Varietas Lokal Dengan Menggunakan Metode Heat Moisture Treatment

    Directory of Open Access Journals (Sweden)

    Zaidiyah Zaidiyah

    2015-10-01

    Full Text Available The effects of heat moisture treatment (110°C and pretreatment on the physicochemical properties of sweet potato dried-noodles starch based were investigated. Completely randomized design was performed which arranged by two-factor. The first factor is noodles consist of native starch and treated starch (heat moisture treatment. The second factor is a type of sweet potato local varieties which consists of three levels: orange, purple and cream flesh color, respectively. Native starch and treated starch treatment showed significant effect on water content, protein and carbohydrate/fiber. Water absorption and cooking loss of dried noodle is highly different between native (non-HMT and treated starch (HMT.

  11. Modeling of precipitation and Cr depletion profiles of Inconel 600 during heat treatments and LSM procedure

    Energy Technology Data Exchange (ETDEWEB)

    Bao Gang [Department of Mechanical System Engineering, Hiroshima University, 1-4-1 Higashi-Hiroshima, Hiroshima (Japan); Shinozaki, Kenji [Department of Mechanical System Engineering, Hiroshima University, 1-4-1 Higashi-Hiroshima, Hiroshima (Japan)]. E-mail: kshino@hiroshima-u.ac.jp; Inkyo, Muneyuki [Department of Mechanical System Engineering, Hiroshima University, 1-4-1 Higashi-Hiroshima, Hiroshima (Japan); Miyoshi, Tomohisa [Department of Mechanical System Engineering, Hiroshima University, 1-4-1 Higashi-Hiroshima, Hiroshima (Japan); Yamamoto, Motomichi [Department of Mechanical System Engineering, Hiroshima University, 1-4-1 Higashi-Hiroshima, Hiroshima (Japan); Mahara, Yoichi [Babcock-Hitachi K.K., 3-36 Takara-machi, Kure, Hiroshima (Japan); Watanabe, Hiroshi [Babcock-Hitachi K.K., 3-36 Takara-machi, Kure, Hiroshima (Japan)

    2006-08-10

    A model based on the thermodynamic and kinetic was conducted to simulate the Cr depletion profiles near the grain boundary in Inconel 600 during the heat treatments and laser surface melting (LSM) process using Thermo-Calc and Dictra code. Based on the good agreement of Cr concentration distribution during heat treatments measured by experiments, the microsegregation of Cr induced by cellular microstructure formed during the LSM process was also modeled. The Cr depletion profile was evaluated using the Cr depletion area below the critical Cr concentration for intergranular cracking/intergranular stress corrosion cracking (IGC/IGSCC) susceptibility (8 mass%). Comparing with the result of Streicher test, the Cr depletion area calculated showed good coherence with the IGC/IGSCC susceptibility. The sample after SR + LTS treatment with the largest Cr depletion area showed the worst IGC/IGSCC resistance, while, the sample after LSM process with the smaller Cr depletion area showed the excellent IGC/IGSCC resistance.

  12. Design of heat treatments for 9-12%Cr steels to optimise creep resistance for power plant applications

    Energy Technology Data Exchange (ETDEWEB)

    Morris, P.F.; Sachadel, U.A.; Clarke, P.D. [Tata Steel Europe, Rotherham (United Kingdom). Swinden Technology Centre; CRD and T, IJmuiden (Netherlands)

    2010-07-01

    Optimisation of the creep rupture properties of Steel 92 (9%Cr, 0.5%Mo, 2%W) by modification of heat treatment and C:N ratio has been studied. It was shown that a higher austenization temperature and double tempering at lower temperature can significantly extend creep life of the standard composition. The increase in austenization temperature from 1060 C and double tempering at 660 C/3h instead of single tempering at 780 C/2h resulted in the increase of stress rupture life from 1,734 to 6,179h at 650 C/110MPa. Even greater improvement in creep life was achieved by the combination of the modified heat treatment and decreased C:N ratio. In this case the creep life was extended to 10,255 h at 650 C/110MPa. A further increase in austenitization temperature to 1200 C for the decreased C:N ratio variant extended the rupture life to 17,118h. Initial results indicate that this modified heat treatment schedule does not result in notch brittle behaviour and most of the improvement in creep strength remains after a simulated post weld heat treatment at 740 C. The stress rupture programme is continuing and at 600 C test durations are approaching 60,000h. To explain the effect on rupture life thermodynamic calculations, microscopic investigations and a literature study were performed. Electron metallography investigations revealed that the lower tempering temperature resulted in a finer distribution of nano-size particles. Calculations show that increasing the austenitization temperature gave more dissolved B, N, C, Nb and V. The lower C:N ratio resulted in a higher atomic fraction of N in nano-size particles on subsequent tempering. Dissolved B should stabilize M{sub 23}M{sub 6} and dissolved N, C, Nv, and V should allow precipitation of a higher volume fraction of nano-size carbo-nitrides during tempering. Literature data suggest that lower tempering temperatures could also change their type from MX to M{sub 2}X. (orig.)

  13. 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.

  14. Influence of prolonged storage process, pasteurization, and heat treatment on biologically-active human milk proteins.

    Science.gov (United States)

    Chang, Jih-Chin; Chen, Chao-Huei; Fang, Li-Jung; Tsai, Chi-Ren; Chang, Yu-Chuan; Wang, Teh-Ming

    2013-12-01

    The bioactive proteins in human milk may be influenced by prolonged storage process, pasteurization, and heat treatment. This study was conducted to evaluate the effects of these procedures. Three forms of human milk - freshly expressed, frozen at -20°C for a prolonged duration, and pasteurized milk - were collected from 14 healthy lactating mothers and a milk bank. The concentrations of major bioactive proteins (secretory immunoglobulin A, lactoferrin, lysozyme, and leptin) were quantified using enzyme-linked immunosorbent assay kits. Changes in these proteins by heat treatment at 40°C or 60°C for 30 minutes were further evaluated. The mean concentrations of lactoferrin and secretory immunoglobulin A were significantly reduced by 66% and 25.9%, respectively, in pasteurized milk compared with those in freshly-expressed milk. Heat treatment at 40°C or 60°C did not cause significant changes in lactoferrin and secretory immunoglobulin A, but there was an apparent increase in lysozyme (p = 0.016). There were no significant differences in leptin level among these three forms of milk prior to (p = 0.153) or after heat treatment (p = 0.053). Various freezing/heating/pasteurization processes applied to human milk prior to delivery to neonates could affect the concentration of immunomodulatory proteins, especially lactoferrin, secretory immunoglobulin A, and lysozyme. Leptin was unaffected by the various handling processes tested. Fresh milk was found to be the best food for neonates. Further studies are warranted to evaluate the functional activity of these proteins and their effects on infants' immunological status. Copyright © 2013. Published by Elsevier B.V.

  15. Influence of heat treatment on the structural and magnetic characteristics of (NdxPr1-x2Fe14B-based magnetic material for low-temperature application

    Directory of Open Access Journals (Sweden)

    K. Skotnicová

    2016-10-01

    Full Text Available Sintered Pr-Nd-Fe-B-based permanent magnets with 10 and 13 wt. % of Pr were prepared by traditional technology and then subjected to various heat treatments. Stoichiometric composition of the matrix grains corresponds to (Pr0.3Nd0.72Fe14B and (Pr0.4Nd0.62Fe14B compounds, respectively. Conducted thermomagnetic analysis to samples of these magnets showed the presence of spin-reorientation transition in temperature 95 and 75 K, respectively. This makes the magnet potentially applicable for low temperatures. For these compounds, we have determined the optimum heat-treatment conditions. The magnetic domain structure of the magnet subjected to an optimum heat treatment has been studied. The effect of different low-temperature heat treatments on the magnetic properties of magnets has been demonstrated.

  16. Making use of guava seed (Psidium guajava L): the effects of pre-treatments on its chemical composition.

    Science.gov (United States)

    Chang, Ying Ping; Tan, May Ping; Lok, Wai Li; Pakianathan, Suganthi; Supramaniam, Yasoga

    2014-03-01

    The guava processing industry in Malaysia produces by-products in the form of seed core and peel. These by-products can be regarded as underused resources but there are concerns about their composition that prevent their use in the food and feed industries. This study aims to analyze the respective effects of heat treatments (boiling or autoclaving) and germination periods on the nutritional composition and phytochemical content of guava seeds. The guava seeds were found to contain 618, 78, 72, and 5 mg/g dry weight total dietary fiber, fat, protein, and ash, respectively. The tannin and saponin contents, but not the phytic acid content, were below the respective anti-nutritional thresholds. The heat treatments did not affect the total dietary fiber and ash contents but reduced all other chemical components to different extents (15-91%). Boiling did not reduce the phytic acid content substantially but autoclaving caused a reduction of 91% to a level below the anti-nutritional threshold. Germination for 14 days caused a significant reduction in nutrient contents in the range of 16-79%. Germination also reduced the phytic acid content by 90% in the seed but did not significantly affect the saponin content. Thus, guava seed can be treated thermally or germinated to manipulate its chemical composition to enable its use in the food and feed industries.

  17. The Variations of Thermal Contact Resistance and Heat Transfer Rate of the AlN Film Compositing with PCM

    Directory of Open Access Journals (Sweden)

    Huann-Ming Chou

    2015-01-01

    Full Text Available The electrical industries have been fast developing over the past decades. Moreover, the trend of microelements and packed division multiplex is obviously for the electrical industry. Hence, the high heat dissipative and the electrical insulating device have been popular and necessary. The thermal conduct coefficient of aluminum nitride (i.e., AlN is many times larger than the other materials. Moreover, the green technology of composite with phase change materials (i.e., PCMs is worked as a constant temperature cooler. Therefore, PCMs have been used frequently for saving energy and the green environment. Based on the above statements, it does show great potential in heat dissipative for the AlN film compositing with PCM. Therefore, this paper is focused on the research of thermal contact resistance and heat transfer between the AlN/PCM pairs. According to the experimental results, the heat transfer decreases and the thermal contact resistance increases under the melting process of PCM. However, the suitable parameters such as contact pressures can be used to improve the above defects.

  18. Effects of post heat-treatment on surface characteristics and adhesive bonding performance of medium density fiberboard

    Science.gov (United States)

    Nadir Ayrilimis; Jerrold E. Winandy

    2009-01-01

    A series of commercially manufactured medium density fiberboard (MDF) panels were exposed to a post-manufacture heat-treatment at various temperatures and durations using a hot press and just enough pressure to ensure firm contact between the panel and the press platens. Post-manufacture heat-treatment improved surface roughness of the exterior MDF panels. Panels...

  19. Nanoclay/Polymer Composite Powders for Use in Laser Sintering Applications: Effects of Nanoclay Plasma Treatment

    Science.gov (United States)

    Almansoori, Alaa; Majewski, Candice; Rodenburg, Cornelia

    2017-11-01

    Plasma-etched nanoclay-reinforced Polyamide 12 (PA12) powder is prepared with its intended use in selective laser sintering (LS) applications. To replicate the LS process we present a downward heat sintering (DHS) process, carried out in a hot press, to fabricate tensile test specimens from the composite powders. The DHS parameters are optimized through hot stage microscopy, which reveal that the etched clay (EC)-based PA12 (EC/PA12) nanocomposite powder melts at a temperature 2°C higher than that of neat PA12, and 1-3°C lower than that of the nonetched clay-based nanocompsite (NEC/PA12 composite). We show that these temperature differences are critical to successful LS. The distribution of EC and NEC onto PA12 is investigated by scanning electron microscopy (SEM). SEM images show clearly that the plasma treatment prevents the micron-scale aggregation of the nanoclay, resulting in an improved elastic modulus of EC/PA12 when compared with neat PA12 and NEC/PA12. Moreover, the reduction in elongation at break for EC/PA12 is less pronounced than for NEC/PA12.

  20. Modelling of volumetric composition and mechanical properties of unidirectional hemp/epoxy composites - Effect of enzymatic fibre treatment

    Science.gov (United States)

    Liu, M.; Thygesen, A.; Meyer, AS; Madsen, B.

    2016-07-01

    The objective of the present study is to assess the effect of enzymatic fibre treatments on the fibre performance in unidirectional hemp/epoxy composites by modelling the volumetric composition and mechanical properties of the composites. It is shown that the applied models can well predict the changes in volumetric composition and mechanical properties of the composites when differently treated hemp fibres are used. The decrease in the fibre correlated porosity factor with the enzymatic fibre treatments shows that the removal of pectin by pectinolytic enzymes results in a better fibre impregnation by the epoxy matrix, and the mechanical properties of the composites are thereby increased. The effective fibre stiffness and strength established from the modelling show that the enzymatic removal of pectin also leads to increased mechanical properties of the fibres. Among the investigated samples, the composites with hydrothermally pre-treated and enzymatically treated fibres have the lowest porosity factor of 0.08 and the highest mechanical properties. In these composites, the effective fibre stiffness and strength are determined to be 83 GPa and 667 MPa, respectively, when the porosity efficiency exponent is set equal to 2. Altogether, it is demonstrated that the applied models provide a concept to be used for the evaluation of performance of treated fibres in composites.